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  <front>
    <journal-meta>
      <journal-id journal-id-type="publisher-id">abc</journal-id>
      <journal-title-group>
        <journal-title>Arquivos Brasileiros de Cardiologia</journal-title>
        <abbrev-journal-title abbrev-type="publisher">Arq. Bras. Cardiol.</abbrev-journal-title>
      </journal-title-group>
      <issn pub-type="ppub">0066-782X</issn>
      <issn pub-type="epub">1678-4170</issn>
      <publisher>
        <publisher-name>Sociedade Brasileira de Cardiologia - SBC</publisher-name>
        <publisher-loc>S&#227;o Paulo, SP, Brazil</publisher-loc>
      </publisher>
    </journal-meta>
    <article-meta>
      <article-id pub-id-type="publisher-id" specific-use="scielo-v3">7DkK7r94ML9KJYWXpzhYJHw</article-id>
      <article-id pub-id-type="publisher-id" specific-use="scielo-v2">S0066-782X2013003000005</article-id>
      <article-id pub-id-type="publisher-id" specific-use="scielo-v1">S0066-782X(13)10100400005</article-id>
      <article-id pub-id-type="doi">10.5935/abc.20130182</article-id>
      <article-categories>
        <subj-group subj-group-type="heading">
          <subject>Artigos Originais</subject>
        </subj-group>
      </article-categories>
      <title-group>
        <article-title>Altera&#231;&#227;o precoce da matriz extracelular e par&#226;metros diast&#243;licos na s&#237;ndrome metab&#243;lica</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <name>
            <surname>Santos</surname>
            <given-names>Angela B. S.</given-names>
          </name>
          <xref ref-type="aff" rid="aff01"/>
          <xref ref-type="aff" rid="aff02"/>
        </contrib>
        <contrib contrib-type="author">
          <name>
            <surname>Junges</surname>
            <given-names>Mauricio</given-names>
          </name>
          <xref ref-type="aff" rid="aff02"/>
        </contrib>
        <contrib contrib-type="author">
          <name>
            <surname>Silvello</surname>
            <given-names>Daiane</given-names>
          </name>
          <xref ref-type="aff" rid="aff02"/>
        </contrib>
        <contrib contrib-type="author">
          <name>
            <surname>Macari</surname>
            <given-names>Adriana</given-names>
          </name>
          <xref ref-type="aff" rid="aff02"/>
        </contrib>
        <contrib contrib-type="author">
          <name>
            <surname>Ara&#250;jo</surname>
            <given-names>Bruno S. de</given-names>
          </name>
          <xref ref-type="aff" rid="aff02"/>
        </contrib>
        <contrib contrib-type="author">
          <name>
            <surname>Seligman</surname>
            <given-names>Beatriz G.</given-names>
          </name>
          <xref ref-type="aff" rid="aff01"/>
          <xref ref-type="aff" rid="aff02"/>
        </contrib>
        <contrib contrib-type="author">
          <name>
            <surname>Duncan</surname>
            <given-names>Bruce B.</given-names>
          </name>
          <xref ref-type="aff" rid="aff02"/>
        </contrib>
        <contrib contrib-type="author">
          <name>
            <surname>Rohde</surname>
            <given-names>Luis Eduardo P.</given-names>
          </name>
          <xref ref-type="aff" rid="aff01"/>
          <xref ref-type="aff" rid="aff02"/>
        </contrib>
        <contrib contrib-type="author">
          <name>
            <surname>Clausell</surname>
            <given-names>Nadine</given-names>
          </name>
          <xref ref-type="aff" rid="aff01"/>
          <xref ref-type="aff" rid="aff02"/>
        </contrib>
        <contrib contrib-type="author">
          <name>
            <surname>Foppa</surname>
            <given-names>Murilo</given-names>
          </name>
          <xref ref-type="aff" rid="aff01"/>
          <xref ref-type="aff" rid="aff02"/>
        </contrib>
      </contrib-group>
      <aff id="aff01">
        <addr-line>
          <named-content content-type="state">Rio Grande do Sul</named-content>
        </addr-line>
        <institution content-type="orgname">Universidade Federal do Rio Grande do Sul</institution>
        <country country="BR">Brazil</country>
      </aff>
      <aff id="aff02">
        <addr-line>
          <named-content content-type="city">Porto Alegre</named-content>
          <named-content content-type="state">Rio Grande do Sul</named-content>
        </addr-line>
        <institution content-type="orgname">Universidade Federal do Rio Grande do Sul</institution>
        <country country="BR">Brazil</country>
      </aff>
      <pub-date date-type="collection" publication-format="electronic">
        <month>10</month>
        <year>2013</year>
      </pub-date>
      <volume>101</volume>
      <issue>4</issue>
      <fpage>311</fpage>
      <lpage>316</lpage>
      <history>
        <date date-type="received">
          <day>01</day>
          <month>12</month>
          <year>2012</year>
        </date>
        <date date-type="accepted">
          <day>07</day>
          <month>06</month>
          <year>2013</year>
        </date>
        <date date-type="rev-recd">
          <day>05</day>
          <month>06</month>
          <year>2013</year>
        </date>
      </history>
      <permissions>
        <license license-type="open-access" xlink:href="http://creativecommons.org/licenses/by-nc/4.0/" xml:lang="en">
          <license-p>This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.</license-p>
        </license>
      </permissions>
      <abstract>
        <p>FUNDAMENTOS: S&#237;ndrome Metab&#243;lica (SM) est&#225; associada com maior risco cardiovascular, por&#233;m n&#227;o est&#225; claro se as altera&#231;&#245;es mioc&#225;rdicas presentes nessa condi&#231;&#227;o, como a disfun&#231;&#227;o diast&#243;lica, s&#227;o consequ&#234;ncia de mecanismos sist&#234;micos ou de efeitos diretos no mioc&#225;rdio. OBJETIVOS: Comparar fun&#231;&#227;o diast&#243;lica, biomarcadores de atividade da Matriz Extracelular (MEC), inflama&#231;&#227;o e estresse hemodin&#226;mico, em pacientes com SM e controles saud&#225;veis. M&#201;TODOS: Pacientes com SM (n = 76) e controles saud&#225;veis (n = 30) foram avaliados clinicamente e submetidos a exame ecocardiogr&#225;fico e mensura&#231;&#227;o dos n&#237;veis plasm&#225;ticos de metaloproteinase-9 (MMP9), inibidor tecidual da metaloproteinase-1 (TIMP1), prote&#237;na C reativa ultrassens&#237;vel (PCR-us), resist&#234;ncia insul&#237;nica (HOMA-RI) e NT-proBNP. RESULTADOS: O grupo SM apresentou menor onda E' (10,1 &#177; 3,0 cm/s vs. 11,9 &#177; 2,6 cm/s, p = 0,005), maiores valores para onda A (63,4 &#177; 14,1 vs. 53,1 &#177; 8,9 cm/s, p &lt; 0,001), raz&#227;o E/E'(8,0 &#177; 2,2 vs. 6,3 &#177; 1,2; p &lt; 0,001), MMP9 (502,9 &#177; 237,1 vs. 330,4 &#177; 162,7 ng/mL, p &lt; 0,001), PCR-us (p = 0,001) e HOMA-RI (p &lt; 0,001), sem diferen&#231;a nos n&#237;veis de TIMP1 e NT-proBNP. Na an&#225;lise multivariada, apenas MMP9 foi independentemente associada a SM. CONCLUS&#195;O: Pacientes com SM apresentaram diferen&#231;as em medidas ecocardiogr&#225;ficas de fun&#231;&#227;o diast&#243;lica, na atividade da MEC, PCR-us e HOMA-RI em rela&#231;&#227;o aos controles. Por&#233;m, somente MMP9 foi independentemente associada com SM. Esses achados sugerem que os efeitos precoces da SM sobre a atividade da MEC podem n&#227;o ser detectados nas medidas ecocardiogr&#225;ficas de fun&#231;&#227;o diast&#243;lica usuais.</p>
      </abstract>
      <kwd-group xml:lang="pt" kwd-group-type="author-generated">
        <kwd>S&#237;ndrome Metab&#243;lica</kwd>
        <kwd>Fatores de Risco</kwd>
        <kwd>Matriz Extracelular</kwd>
        <kwd>Di&#225;stole</kwd>
      </kwd-group>
      <pub-date publication-format="electronic" date-type="pub">
        <day>06</day>
        <month>09</month>
        <year>2013</year>
      </pub-date>
    </article-meta>
  </front>
  <body>
    <p>
      <bold>Altera&#231;&#227;o precoce da matriz extracelular e par&#226;metros diast&#243;licos na s&#237;ndrome metab&#243;lica</bold>
    </p>
    <p>
      <bold>Angela B. S. Santos<sup>I,II</sup>; Mauricio Junges<sup>II</sup>; Daiane Silvello<sup>II</sup>; Adriana Macari<sup>II</sup>; Bruno S. de Ara&#250;jo<sup>II</sup>; Beatriz G. Seligman<sup>I,II</sup>; Bruce B. Duncan<sup>II</sup>; Luis Eduardo P. Rohde<sup>I,II</sup>; Nadine Clausell<sup>I,II</sup>; Murilo Foppa<sup>I,II</sup></bold>
    </p>
    <p><sup>I</sup>Hospital de Cl&#237;nicas de Porto Alegre </p>
    <p><sup>II</sup>Universidade Federal do Rio Grande do Sul, Porto Alegre, RS - Brasil</p>
    <p>
      <xref ref-type="corresp" rid="enda">Correspond&#234;ncia</xref>
    </p>
    <p>
      <bold>RESUMO</bold>
    </p>
    <p><bold>FUNDAMENTOS:</bold> S&#237;ndrome Metab&#243;lica (SM) est&#225; associada com maior risco cardiovascular, por&#233;m n&#227;o est&#225; claro se as altera&#231;&#245;es mioc&#225;rdicas presentes nessa condi&#231;&#227;o, como a disfun&#231;&#227;o diast&#243;lica, s&#227;o consequ&#234;ncia de mecanismos sist&#234;micos ou de efeitos diretos no mioc&#225;rdio. </p>
    <p><bold>OBJETIVOS:</bold> Comparar fun&#231;&#227;o diast&#243;lica, biomarcadores de atividade da Matriz Extracelular (MEC), inflama&#231;&#227;o e estresse hemodin&#226;mico, em pacientes com SM e controles saud&#225;veis. </p>
    <p><bold>M&#201;TODOS:</bold> Pacientes com SM (n = 76) e controles saud&#225;veis (n = 30) foram avaliados clinicamente e submetidos a exame ecocardiogr&#225;fico e mensura&#231;&#227;o dos n&#237;veis plasm&#225;ticos de metaloproteinase-9 (MMP9), inibidor tecidual da metaloproteinase-1 (TIMP1), prote&#237;na C reativa ultrassens&#237;vel (PCR-us), resist&#234;ncia insul&#237;nica (HOMA-RI) e NT-proBNP. </p>
    <p><bold>RESULTADOS:</bold> O grupo SM apresentou menor onda E' (10,1 &#177; 3,0 cm/s vs. 11,9 &#177; 2,6 cm/s, p = 0,005), maiores valores para onda A (63,4 &#177; 14,1 vs. 53,1 &#177; 8,9 cm/s, p &lt; 0,001), raz&#227;o E/E'(8,0 &#177; 2,2 vs. 6,3 &#177; 1,2; p &lt; 0,001), MMP9 (502,9 &#177; 237,1 vs. 330,4 &#177; 162,7 ng/mL, p &lt; 0,001), PCR-us (p = 0,001) e HOMA-RI (p &lt; 0,001), sem diferen&#231;a nos n&#237;veis de TIMP1 e NT-proBNP. Na an&#225;lise multivariada, apenas MMP9 foi independentemente associada a SM. </p>
    <p><bold>CONCLUS&#195;O:</bold> Pacientes com SM apresentaram diferen&#231;as em medidas ecocardiogr&#225;ficas de fun&#231;&#227;o diast&#243;lica, na atividade da MEC, PCR-us e HOMA-RI em rela&#231;&#227;o aos controles. Por&#233;m, somente MMP9 foi independentemente associada com SM. Esses achados sugerem que os efeitos precoces da SM sobre a atividade da MEC podem n&#227;o ser detectados nas medidas ecocardiogr&#225;ficas de fun&#231;&#227;o diast&#243;lica usuais. </p>
    <p><bold>Palavras-chave:</bold> S&#237;ndrome Metab&#243;lica; Fatores de Risco; Matriz Extracelular; Di&#225;stole / fisiopatologia.</p>
    <p>
      <bold>Introdu&#231;&#227;o</bold>
    </p>
    <p>S&#237;ndrome Metab&#243;lica (SM) tem uma preval&#234;ncia estimada em torno de 35% da popula&#231;&#227;o adulta<sup>1,2</sup> e &#233; definida como uma combina&#231;&#227;o de fatores de risco associados com doen&#231;a cardiovascular e diabetes do tipo 2. N&#227;o est&#225; claro se as altera&#231;&#245;es mioc&#225;rdicas presentes nessa condi&#231;&#227;o s&#227;o consequ&#234;ncia de mecanismos sist&#234;micos ou s&#227;o efeitos diretos sobre o mioc&#225;rdio.</p>
    <p>A avalia&#231;&#227;o da fun&#231;&#227;o diast&#243;lica tem sido utilizada para identificar altera&#231;&#245;es card&#237;acas pr&#233;-cl&#237;nicas. Disfun&#231;&#227;o diast&#243;lica &#233; prevalente em pacientes com SM, mesmo na aus&#234;ncia de hipertens&#227;o e diabetes<sup>3</sup> e ajustado para a massa do ventr&#237;culo esquerdo<sup>4,5</sup>. Disfun&#231;&#227;o diast&#243;lica &#233; um marcador de progn&#243;stico desfavor&#225;vel independente de qualquer outra comorbidade<sup>6</sup>. Na s&#237;ndrome metab&#243;lica, a disfun&#231;&#227;o diast&#243;lica &#233; usualmente atribu&#237;da ao aumento do estresse hemodin&#226;mico<sup>7,8</sup>, mas tamb&#233;m pode ser secund&#225;ria a altera&#231;&#245;es da matriz extracelular decorrentes do ambiente inflamat&#243;rio e altera&#231;&#227;o do metabolismo da glicose presentes nessa condi&#231;&#227;o<sup>9</sup>. O <italic>turnover</italic> do col&#225;geno da matriz extracelular &#233; regulado pelo equil&#237;brio entre metaloproteinases e seus inibidores teciduais plasm&#225;ticos. Modifica&#231;&#245;es nesse equil&#237;brio representam outro mecanismo que afeta o relaxamento e a complac&#234;ncia ventricular<sup>10</sup>.</p>
    <p>Com o objetivo de entender melhor os processos envolvidos nas altera&#231;&#245;es cardiovasculares observadas na SM, comparamos par&#226;metros ecocardiogr&#225;ficos de fun&#231;&#227;o diast&#243;lica e n&#237;veis plasm&#225;ticos de metaloproteinase-9 (MMP9), inibidor tecidual da metaloproteinase-1 (TIMP1), prote&#237;na C reativa ultrassens&#237;vel (PCR-us), resist&#234;ncia insul&#237;nica (HOMA-RI) e NT-proBNP em pacientes com SM e controles saud&#225;veis.</p>
    <p>
      <bold>M&#233;todos</bold>
    </p>
    <p>
      <bold>Popula&#231;&#227;o</bold>
    </p>
    <p>Neste estudo transversal, foram selecionados indiv&#237;duos entre 30-55 anos com SM e controles saud&#225;veis (CTR). O grupo SM foi composto por todos os indiv&#237;duos recrutados para um ensaio cl&#237;nico randomizado cujo protocolo e resultados principais j&#225; foram publicados<sup>11</sup>. De uma amostra inicial de 471 volunt&#225;rios avaliados, 76 preencheram os crit&#233;rios de elegibilidade para o estudo, que foram: &#205;ndice de Massa Corporal (IMC) <underline>&gt;</underline> 30 kg/m<sup>2</sup> e <underline>&lt;</underline>40 kg/m<sup>2</sup>, circunfer&#234;ncia abdominal <underline>&gt;</underline> 95 cm e pelo menos dois outros crit&#233;rios para SM de acordo com o <italic>National Cholesterol Education Program Adult Treatment Panel III</italic> (NCEP/ATP III)<sup>12</sup>. Al&#233;m disso, todos os pacientes tinham um teste oral de toler&#226;ncia a glicose negativo para diabetes. Os crit&#233;rios de exclus&#227;o foram gravidez, lacta&#231;&#227;o, creatinina <underline>&gt;</underline>1,5 mg/dL, disfun&#231;&#227;o musculoesquel&#233;tica, doen&#231;as inflamat&#243;rias ou cr&#244;nica do f&#237;gado, tireoide e/ou uso de corticoide ou anorex&#237;genos. Os dados obtidos na linha de base desse grupo foram comparados com uma amostra de controles saud&#225;veis, recrutados localmente, de mesmo sexo e faixa et&#225;ria que o grupo SM. O estudo foi aprovado pelo Comit&#234; de &#201;tica da nossa institui&#231;&#227;o e pelo Comit&#234; de Pesquisa, e todos os participantes assinaram termo de consentimento no in&#237;cio do estudo.</p>
    <p>
      <bold>Avalia&#231;&#227;o cl&#237;nica</bold>
    </p>
    <p>As aferi&#231;&#245;es da press&#227;o arterial e frequ&#234;ncia card&#237;aca foram realizadas em triplicata ap&#243;s cinco minutos de repouso, usando esfigmoman&#244;metro aneroide (Tycos, Welch Allyn, EUA), com valor m&#233;dio relatado. A altura foi medida por um estadi&#244;metro de parede e o peso, por uma balan&#231;a eletr&#244;nica, com os participantes vestindo roupas leves, sem sapatos. A circunfer&#234;ncia abdominal foi medida no ponto m&#233;dio entre o gradil costal e a crista il&#237;aca.</p>
    <p>
      <bold>An&#225;lise bioqu&#237;mica</bold>
    </p>
    <p>Amostras de sangue foram coletadas em jejum. Insulina foi aferida atrav&#233;s de electroquimioluminesc&#234;ncia (Roche, Su&#237;&#231;a), e prote&#237;na C reativa ultrassens&#237;vel (PCR-us), atrav&#233;s de imunonefelometria (Roche, Su&#237;&#231;a). O perfil lip&#237;dico foi medido enzimaticamente (Roche, Su&#237;&#231;a) e o n&#237;vel de LDL-colesterol foi calculado de acordo com a f&#243;rmula de Friedewald, para n&#237;veis de triglicer&#237;deos abaixo de 400 mg/dL. O modelo da homeostase para avalia&#231;&#227;o da resist&#234;ncia a insulina (HOMA-RI) foi usado para determinar resist&#234;ncia insul&#237;nica<sup>13</sup>. Os coeficientes de varia&#231;&#227;o para esses par&#226;metros foram todos abaixo de 6%.</p>
    <p>
      <bold>Estudo ecocardiogr&#225;fico</bold>
    </p>
    <p>As imagens foram obtidas com o aparelho de ultrassom modelo EnVisor C HD (Philips Medical, Andover, MA, EUA), equipado com transdutor sectorial de 4-2 MHz. As imagens digitais est&#225;ticas e din&#226;micas foram enviadas para uma esta&#231;&#227;o de trabalho (ComPACS, Medimatic Srl, It&#225;lia) e lidas <italic>off-line </italic>por um &#250;nico investigador.</p>
    <p>Os di&#226;metros, espessuras do septo e parede posterior do Ventr&#237;culo Esquerdo (VE) foram obtidas atrav&#233;s de imagem bidimensional na janela paraesternal longitudinal. O &#205;ndice do Volume do &#193;trio Esquerdo (IVAE) foi medido na janela apical de 4 c&#226;maras, ao final da s&#237;stole ventricular, utilizando-se o m&#233;todo simplificado de Simpson e indexado para a superf&#237;cie corporal.</p>
    <p>A fun&#231;&#227;o diast&#243;lica foi avaliada a partir do Doppler transmitral<sup>14</sup> e Doppler tecidual do anel mitral<sup>15</sup>, incluindo: velocidade m&#225;xima transmitral de enchimento precoce (onda E) e tardio (onda A) do VE, tempo de desacelera&#231;&#227;o (TD) da onda E e velocidade m&#225;xima de deslocamento do anel mitral septal no in&#237;cio (onda E' ) e no final da di&#225;stole (onda A'). A partir desses valores, as raz&#245;es E/A e E/E' foram calculadas.</p>
    <p>As medidas e sele&#231;&#227;o dos pontos de corte seguiram as recomenda&#231;&#245;es da American Society of Echocardiography, considerando a m&#233;dia de tr&#234;s batimentos card&#237;acos consecutivos<sup>16,17</sup>. Os volumes do VE e fra&#231;&#227;o de eje&#231;&#227;o foram calculados pela f&#243;rmula de Teichholz. A massa do VE foi indexada pela altura &#224; pot&#234;ncia de 2,7(IMVE)<sup>18</sup>. A Espessura Parietal Relativa (EPR) foi definida como (espessura do septo + parede posterior)/di&#226;metro diast&#243;lico do VE. A variabilidade intraleitor foi avaliada em 16 participantes atrav&#233;s do Coeficiente de Varia&#231;&#227;o (CV) e Coeficiente de Correla&#231;&#227;o Intraclasse (CCI), cujos valores foram, respectivamente, onda E' (CV: 5,2% e CCI: 0,99; IC95%: 0,97-0,99), onda E (CV: 4,5% e CCI: 0,98; IC95%: 0,96-0,99), onda A (CV: 3,5% e CCI: 0,98; IC95% 0,97-0,99). As medidas bidimensionais mostraram um CV que variou entre 8% e 13%, com o CCI acima de 0,75, valores semelhantes aos descritos em estudos pr&#233;vios<sup>19,20</sup>.</p>
    <p>
      <bold>ELISA</bold>
    </p>
    <p>Amostras venosas (15 mL) foram coletadas em tubos contendo EDTA, com o participante em jejum. As amostras foram imediatamente centrifugadas a 4&#186; C a 3.000 x g durante 20 minutos e o plasma removido e armazenado a -70&#186;C. Todas as amostras de plasma foram analisadas simultaneamente por um t&#233;cnico de laborat&#243;rio de forma cega. Os n&#237;veis MMP9 e TIMP1 foram medidos em amostras duplicatas com kits dispon&#237;veis comercialmente ELISA (R&amp;D Systems, Minneapolis, MN, EUA). A sensibilidade do ensaio de MMP9 foi &lt; 0,156 ng / mL e a sensibilidade do ensaio de TIMP1 foi &lt; 0,08 ng/mL, com coeficientes de varia&#231;&#227;o intra-e interensaio de 6% e 10%, respectivamente. O n&#237;vel de NT-proBNP foi medido com kit de ELISA comercial (Roche Diagnostic, Fran&#231;a) com sensibilidade do ensaio de &lt; 0,6 pmol/L e coeficientes de varia&#231;&#227;o intra- e interensaio de 1,9% e 3,1%, respectivamente.</p>
    <p>
      <bold>An&#225;lise estat&#237;stica</bold>
    </p>
    <p>Os resultados foram expressos como m&#233;dia e desvio padr&#227;o ou percentagem. Os grupos foram comparados atrav&#233;s do teste <italic>t </italic>de Student para amostras independentes ou qui-quadrado. As associa&#231;&#245;es entre as vari&#225;veis cont&#237;nuas foram testadas com coeficiente de correla&#231;&#227;o de Pearson e regress&#227;o linear m&#250;ltipla para identificar as vari&#225;veis independentemente associadas com a presen&#231;a de SM.</p>
    <p>Foi calculado um tamanho de amostra de 66 SM e 33 CTR, considerando um alfa de 0,05, um poder de 0,8 e uma diferen&#231;a de 0,6 desvios-padr&#227;o nos n&#237;veis de MMP9 entre os grupos. Esse valor foi estimado como equivalente &#224; diferen&#231;a dos n&#237;veis de MMP9 descrita por Tayebjee e cols. <sup>21</sup>, em pacientes hipertensos - que tamb&#233;m apresentam disfun&#231;&#227;o diast&#243;lica - e controles normais. Foi considerado estatisticamente significativo p &lt; 0,05. Todas as an&#225;lises estat&#237;sticas foram realizadas com o pacote de software estat&#237;stico SPSS (SPSS 15.0 Inc., EUA).</p>
    <p>
      <bold>Resultados</bold>
    </p>
    <p>Foram analisados 76 pacientes com SM (43,3 &#144;&#177; 7,9 anos, 65% homens) e 30 controles saud&#225;veis (40,9 &#144;&#177; 6,6 anos, 63% homens). As demais caracter&#237;sticas cl&#237;nicas e os achados laboratoriais dos grupos s&#227;o apresentados na <xref ref-type="table" rid="aop_5302tab01">tabela 1</xref>. O grupo SM, como esperado, tinha maiores peso, circunfer&#234;ncia abdominal, frequ&#234;ncia card&#237;aca, press&#227;o arterial e n&#237;veis de colesterol em compara&#231;&#227;o ao grupo CTR.</p>
    <p content-type="asset">
      <table-wrap id="aop_5302tab01">
        <graphic xlink:href="1678-4170-abc-101-04-0311-30182-gt01.jpg"/></table-wrap>
    </p>
    <p>O &#205;ndice de Massa do Ventr&#237;culo Esquerdo (IMVE) foi maior no grupo SM (<xref ref-type="table" rid="aop_5302tab02">Tabela 2</xref>). O Volume Indexado do &#193;trio Esquerdo (IVAE) e a fra&#231;&#227;o de eje&#231;&#227;o n&#227;o diferiram entre os grupos.</p>
    <p content-type="asset">
      <table-wrap id="aop_5302tab02">
        <graphic xlink:href="1678-4170-abc-101-04-0311-30182-gt02.jpg"/></table-wrap>
    </p>
    <p>Em rela&#231;&#227;o aos par&#226;metros de fun&#231;&#227;o diast&#243;lica, o grupo SM mostrou maior onda A (63,4 &#144;&#177; 14,1 cm/s vs. 53,1 &#144;&#177; 8,9 cm/s, p &lt; 0,001) e menor onda E' (10,1 &#144;&#177; 3,0 cm/s vs. 11,9 &#144;&#177; 2,6 cm/s, p = 0,005) comparados aos controles, mas com valores m&#233;dios ainda dentro da faixa da normalidade<sup>17</sup>. Essas diferen&#231;as refletiram-se em uma menor raz&#227;o E/A (p = 0,05) e maior raz&#227;o E/E' (p &lt; 0,001) no grupo SM. A onda E (p = 0,45) e o tempo de desacelera&#231;&#227;o mitral (p = 0,98) n&#227;o diferiram entre os grupos (<xref ref-type="table" rid="aop_5302tab02">Tabela 2</xref>).</p>
    <p>Os biomarcadores de atividade da matriz extracelular mostraram n&#237;veis de MMP9 maiores no grupo SM (502,9 &#144;&#177; 237,1 ng/mL vs. 330,4 &#144;&#177; 162,7 ng/mL, p &lt; 0,001), mas sem diferen&#231;a nos n&#237;veis de TIMP1 (210,2 &#144;&#177; 55,6 ng/mL vs. 220,2 &#144;&#177; 57,2 ng/mL, p = 0,41) (<xref ref-type="fig" rid="aop_5302fig01">Figura 1</xref>). A resist&#234;ncia a insulina medida pelo HOMA-RI (p &lt; 0,001) e os n&#237;veis de PCR-us (p = 0,001) foram maiores no grupo SM, enquanto os n&#237;veis de NT-proBNP (p = 0,19) n&#227;o apresentaram diferen&#231;a estatisticamente significativa entre os grupos (<xref ref-type="table" rid="aop_5302tab03">Tabela 3</xref>).</p>
    <p content-type="asset">
      <fig id="aop_5302fig01">
        <graphic xlink:href="1678-4170-abc-101-04-0311-30182-gf01.jpg"/></fig>
    </p>
    <p content-type="asset">
      <table-wrap id="aop_5302tab03">
        <graphic xlink:href="1678-4170-abc-101-04-0311-30182-gt03.jpg"/></table-wrap>
    </p>
    <p>Na regress&#227;o linear m&#250;ltipla, investigamos as associa&#231;&#245;es de press&#227;o arterial, IMC, circunfer&#234;ncia abdominal, n&#237;veis de HDL-colesterol, triglicer&#237;deos, HOMA-RI, PCR-us, MMP9, TIMP1 e NT-proBNP, onda E, onda A, onda E' e onda A' com s&#237;ndrome metab&#243;lica. Apenas MMP9 (&#946; = 0,13; p = 0,03) foi independentemente associada com SM.</p>
    <p>
      <bold>Discuss&#227;o</bold>
    </p>
    <p>Em nosso estudo, o grupo SM mostrou diferen&#231;a nos par&#226;metros de fun&#231;&#227;o diast&#243;lica e maiores n&#237;veis de HOMA-RI, PCR-us e MMP9 em compara&#231;&#227;o a controles saud&#225;veis, sem diferen&#231;a nos n&#237;veis de TIMP1 e NT-proBNP. No entanto, quando ajustados para covari&#225;veis, apenas os n&#237;veis de MMP9 foram independentemente associados com SM.</p>
    <p>De las Fuentes e cols. <sup>4</sup>, investigando par&#226;metros ecocardiogr&#225;ficos de fun&#231;&#227;o diast&#243;lica na SM, mostraram aumento da onda A e diminui&#231;&#227;o da onda E', sem diferen&#231;a na onda E no grupo SM. Embora tenhamos encontrado resultados semelhantes, esses par&#226;metros ecocardiogr&#225;ficos n&#227;o foram independentemente associados com SM ap&#243;s o ajuste para covari&#225;veis. J&#225; os n&#237;veis de MMP9 mantiveram-se associados a SM, permitindo inferir que nas fases iniciais da SM, modula&#231;&#245;es da atividade da MEC representadas por aumento dos n&#237;veis de MMP9 antecipam altera&#231;&#245;es hemodin&#226;micas detectadas pelos n&#237;veis de NT-proBNP e por par&#226;metros ecocardiogr&#225;ficos usando o Doppler e dimens&#245;es do &#225;trio esquerdo, m&#233;todos frequentemente utilizados como marcadores de sobrecarga press&#243;rica<sup>22,23</sup>.</p>
    <p>A atividade da matriz extracelular tem sido associada ao relaxamento e &#224; rigidez do ventr&#237;culo esquerdo<sup>9</sup>. O aumento dos n&#237;veis de MMP9, na s&#237;ndrome metab&#243;lica, pode representar um maior <italic>turnover</italic> de col&#225;geno da matriz extracelular e contribuir para rigidez do ventr&#237;culo esquerdo e remodelamento ventricular adverso. Gon&#231;alves e cols.<sup>24</sup>, estudando 25 pacientes com SM e 25 controles saud&#225;veis, encontraram n&#237;veis aumentados tanto de MMP9 como TIMP1 no grupo SM, refletindo o estado mais avan&#231;ado de dismetabolismo comparados aos nossos pacientes.</p>
    <p>A simplifica&#231;&#227;o de mecanismos multifatoriais com o emprego de um n&#250;mero restrito de marcadores &#233; uma limita&#231;&#227;o inerente a esse tipo de estudo, assim como a impossibilidade de infer&#234;ncias causais. Um potencial vi&#233;s dessa an&#225;lise foi a aquisi&#231;&#227;o dos exames ecocardiogr&#225;ficos de forma n&#227;o cega para os grupos, minimizado pela leitura <italic>off-line</italic> por um &#250;nico investigador. Devemos tamb&#233;m chamar a aten&#231;&#227;o para o potencial papel das tecnologias mais recentes, como o <italic>speckle tracking</italic>, que poderiam identificar altera&#231;&#245;es subcl&#237;nicas precoces de forma mais precisa.</p>
    <p>
      <bold>Conclus&#245;es</bold>
    </p>
    <p>Encontramos diferen&#231;as em medidas ecocardiogr&#225;ficas de fun&#231;&#227;o diast&#243;lica, atividade da MEC medida pelos n&#237;veis de MMP9, PCR-us e HOMA-RI em pacientes com SM comparados a controles saud&#225;veis. Por&#233;m, somente MMP9 foi independentemente associada com SM. Esses achados sugerem que os efeitos precoces da SM sobre a atividade da MEC podem n&#227;o ser detectados nas medidas ecocardiogr&#225;ficas usualmente empregadas para avaliar fun&#231;&#227;o diast&#243;lica.</p>
    <p>
      <bold>Contribui&#231;&#227;o dos autores</bold>
    </p>
    <p>Concep&#231;&#227;o e desenho da pesquisa: Santos ABS, Junges M, Silvello D, Macari A, Ara&#250;jo BS, Seligman BG, Duncan BB, Clausell N, Foppa M; Obten&#231;&#227;o de dados: Santos ABS, Junges M, Silvello D, Macari A, Ara&#250;jo BS, Seligman BG, Foppa M; An&#225;lise e interpreta&#231;&#227;o dos dados: Santos ABS, Junges M, Silvello D, Seligman BG, Rohde LEP, Clausell N, Foppa M; An&#225;lise estat&#237;stica: Santos ABS, Foppa M; Obten&#231;&#227;o de financiamento: Santos ABS, Duncan BB, Foppa M; Reda&#231;&#227;o do manuscrito: Santos ABS, Seligman BG, Duncan BB, Clausell N, Foppa M; Revis&#227;o cr&#237;tica do manuscrito quanto ao conte&#250;do intelectual: Santos ABS, Seligman BG, Duncan BB, Rohde LEP, Clausell N, Foppa M.</p>
    <p>
      <bold>Potencial Conflito de Interesses</bold>
    </p>
    <p>Declaro n&#227;o haver conflito de interesses pertinentes.</p>
    <p>
      <bold>Fontes de Financiamento</bold>
    </p>
    <p>O presente estudo foi financiado pelo CNPq e FIPE/HCPA.</p>
    <p>
      <bold>Vincula&#231;&#227;o Acad&#234;mica</bold>
    </p>
    <p>Este artigo &#233; parte de disserta&#231;&#227;o de Mestrado de Angela Barreto Santiago Santos pela Universidade Federal do Rio Grande do Sul.</p>
    <p>
      <fn id="enda" fn-type="corresp">
        <label>
          <bold>Correspond&#234;ncia:</bold>
        </label>
        <p> Angela Barreto Santiago Santos </p>
        <p> Hospital de Clinicas de Porto Alegre - Divis&#227;o Cardiovascular </p>
        <p> Rua Ramiro Barcelos, 2350, Sala 2061 </p>
        <p> CEP 90035-903, Porto Alegre, RS &#150; Brasil </p>
        <p> E-mail: </p>
        <p>
          <email xlink:href="angelabssantos@yahoo.com.br">angelabssantos@yahoo.com.br</email>
        </p>
      </fn>
    </p>
    <p>Artigo recebido em 01/12/12; revisado em 05/06/13; aceito em 07/06/13.</p>
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  <sub-article article-type="translation" id="TRen" xml:lang="en">
    <front-stub>
      <article-categories>
        <subj-group subj-group-type="heading">
          <subject>Original Articles</subject>
        </subj-group>
      </article-categories>
      <title-group>
        <article-title xml:lang="en">Early change of extracellular matrix and diastolic parameters in metabolic syndrome</article-title>
      </title-group>
      <abstract xml:lang="en">
        <p>BACKGROUND: Metabolic syndrome (MS) is associated with increased cardiovascular risk. It is not clear whether myocardial changes showed in this syndrome, such as diastolic dysfunction, are due to the systemic effects of the syndrome, or to specific myocardial effects. OBJECTIVES: Compare diastolic function, biomarkers representing extracellular matrix activity (ECM), inflammation and cardiac hemodynamic stress in patients with the MS and healthy controls. METHODS: MS patients (n=76) and healthy controls (n=30) were submitted to a clinical assessment, echocardiographic study, and measurement of plasma levels of metalloproteinase-9 (MMP9), tissue inhibitor of metalloproteinase-1 (TIMP1), ultrasensitive-reactive-C-Protein (us-CRP), insulin resistance (HOMA-IR) and natriuretic peptide (NT-proBNP). RESULTS: MS group showed lower E' wave (10.1 &#65533;&#177; 3.0 cm/s vs 11.9 &#65533;&#177; 2.6 cm/s, p = 0.005), increased A wave (63.4 &#65533;&#177; 14.1 cm/s vs. 53.1 &#65533;&#177; 8.9 cm/s; p &lt; 0.001), E/E' ratio (8.0 &#65533;&#177; 2.2 vs. 6.3 &#65533;&#177; 1.2; p &lt; 0.001), MMP9 (502.9 &#65533;&#177; 237.1 ng/mL vs. 330.4&#65533;&#177;162.7 ng/mL; p &lt; 0.001), us-CRP (p = 0.001) and HOMA-IR (p &lt; 0.001), but no difference for TIMP1 or NT-proBNP levels. In a multivariable analysis, only MMP9 was independently associated with MS. CONCLUSION: MS patients showed differences for echocardiographic measures of diastolic function, ECM activity, us-CRP and HOMA-IR when compared to controls. However, only MMP9 was independently associated with the MS. These findings suggest that there are early effects on ECM activity, which cannot be tracked by routine echocardiographic measures of diastolic function.</p>
      </abstract>
      <kwd-group xml:lang="en">
        <kwd>Metabolic Syndrome</kwd>
        <kwd>Risk Factors</kwd>
        <kwd>Extracellular Matrix</kwd>
        <kwd>Diastole</kwd>
      </kwd-group>
    </front-stub>
    <body>
      <p>
        <fn id="end-body2">
          <label>
            <bold>Early change of extracellular matrix and diastolic parameters in metabolic syndrome</bold>
          </label>
          <p>
            <bold>Angela B. S. Santos<sup>I,II</sup>; Mauricio Junges<sup>II</sup>; Daiane Silvello<sup>II</sup>; Adriana Macari<sup>II</sup>; Bruno S. de Ara&#250;jo<sup>II</sup>; Beatriz G. Seligman<sup>I,II</sup>; Bruce B. Duncan<sup>II</sup>; Luis Eduardo P. Rohde<sup>I,II</sup>; Nadine Clausell<sup>I,II</sup>; Murilo Foppa<sup>I,II</sup></bold>
          </p>
        </fn>
      </p>
      <p><sup>I</sup>Hospital de Cl&#237;nicas de Porto Alegre</p>
      <p><sup>II</sup>Universidade Federal do Rio Grande do Sul, Porto Alegre, RS - Brazil</p>
      <p>Mailing Address</p>
      <p>
        <bold>ABSTRACT</bold>
      </p>
      <p><bold>BACKGROUND:</bold> Metabolic syndrome (MS) is associated with increased cardiovascular risk. It is not clear whether myocardial changes showed in this syndrome, such as diastolic dysfunction, are due to the systemic effects of the syndrome, or to specific myocardial effects.</p>
      <p><bold>OBJECTIVES:</bold> Compare diastolic function, biomarkers representing extracellular matrix activity (ECM), inflammation and cardiac hemodynamic stress in patients with the MS and healthy controls.</p>
      <p><bold>METHODS:</bold> MS patients (n=76) and healthy controls (n=30) were submitted to a clinical assessment, echocardiographic study, and measurement of plasma levels of metalloproteinase-9 (MMP9), tissue inhibitor of metalloproteinase-1 (TIMP1), ultrasensitive-reactive-C-Protein (us-CRP), insulin resistance (HOMA-IR) and natriuretic peptide (NT-proBNP).</p>
      <p><bold>RESULTS:</bold> MS group showed lower E' wave (10.1 &#144;&#177; 3.0 cm/s vs 11.9 &#144;&#177; 2.6 cm/s, p = 0.005), increased A wave (63.4 &#144;&#177; 14.1 cm/s vs. 53.1 &#144;&#177; 8.9 cm/s; p &lt; 0.001), E/E' ratio (8.0 &#144;&#177; 2.2 vs. 6.3 &#144;&#177; 1.2; p &lt; 0.001), MMP9 (502.9 &#144;&#177; 237.1 ng/mL vs. 330.4&#144;&#177;162.7 ng/mL; p &lt; 0.001), us-CRP (p = 0.001) and HOMA-IR (p &lt; 0.001), but no difference for TIMP1 or NT-proBNP levels. In a multivariable analysis, only MMP9 was independently associated with MS.</p>
      <p><bold>CONCLUSION:</bold> MS patients showed differences for echocardiographic measures of diastolic function, ECM activity, us-CRP and HOMA-IR when compared to controls. However, only MMP9 was independently associated with the MS. These findings suggest that there are early effects on ECM activity, which cannot be tracked by routine echocardiographic measures of diastolic function. </p>
      <p><bold>Keywords:</bold> Metabolic Syndrome; Risk Factors; Extracellular Matrix; Diastole / physiopathology.</p>
      <p>
        <bold>Introduction</bold>
      </p>
      <p>The metabolic syndrome (MS) is defined as a combination of several risk factors associated with cardiovascular disease and type 2 diabetes; estimates suggest that this disease affects approximately 35% of the adult population<sup>1,2</sup>. It is unclear whether myocardial changes associated with the metabolic syndrome are consequences of the systemic effects of the syndrome or due to direct myocardial effects.</p>
      <p>The diastolic function evaluation has been used to identify cardiac preclinical changes. Diastolic dysfunction is prevalent in patients with MS, even in the absence of hypertension and diabetes<sup>3</sup>, and regardless the left ventricular mass<sup>4,5</sup>. Diastolic dysfunction predicts a worse outcome independently of any other co-morbidity<sup>6</sup>. In MS, diastolic dysfunction is usually attributed to the increased hemodynamic stress<sup>7,8</sup>. Alternatively, diastolic dysfunction may also be secondary to changes in the cardiac extracellular matrix resulting from the altered metabolic-inflammatory milieu and glucose metabolism<sup>9</sup>. Extracellular matrix collagen turnover is tightly regulated by the interaction between metalloproteinases and its plasma tissue inhibitors. Changes in this balance may therefore influence ventricular relaxation and compliance<sup>10</sup>.</p>
      <p>Aiming to a better understand on the underlying processes involved in the cardiovascular abnormalities seen in MS, we studied echocardiographic parameters of diastolic function and quantified plasma levels of metalloproteinase-9 (MMP9), tissue inhibitor of metalloproteinase-1 (TIMP1), ultrasensitive-reactive-C-Protein (us-CRP), insulin resistance (HOMA-IR) and natriuretic peptide (NT-proBNP) in patients with MS compared to healthy controls.</p>
      <p>
        <bold>Methods</bold>
      </p>
      <p>
        <bold>Population</bold>
      </p>
      <p>In this cross-sectional analysis, we selected subjects ranging from 30-55 years of age with MS and healthy controls (CTR). The MS group consisted of all subjects recruited for a randomized clinical trial whose protocol and results have already been published<sup>11</sup>. From the initial sample of 471 evaluated volunteers, 76 matched the clinical trial eligibility criteria, which were: Body Mass Index (BMI) <underline>&gt;</underline> 30 kg/m<sup>2 </sup>and <underline>&lt;</underline> 40 kg/m<sup>2</sup>, waist circumference <underline>&gt;</underline> 95 cm and at least two other Metabolic Syndrome criteria according to the National Cholesterol Education Program Adult Treatment Panel III (NCEP/ATP III)<sup>12</sup>. Moreover, all patients had an oral glucose tolerance test that was negative for diabetes. The exclusion criteria were pregnancy, lactation, creatinine <underline>&gt;</underline> 1.5 mg/dL, musculoskeletal dysfunction, inflammatory or chronic liver disease, thyroid dysfunction and/or use of corticosteroids or anorectic drugs. The baseline data in this group were compared with locally recruited healthy subjects of same gender and age range as that of MS group. The study was approved by the Ethics Committee of our Institution and by the Research Committee, and all participants signed a written informed consent prior to enrollment.</p>
      <p>
        <bold>Clinical Assessment</bold>
      </p>
      <p>Blood pressure and heart rate were measured in triplicate after five minutes at rest using an aneroid sphygmomanometer (Tycos, Welch Allyn, USA), with reported average. Height was measured by a wall-mounted stadiometer, and patients had their weight measured by an electronic scale, wearing light clothes and no shoes. Waist circumference was measured midway between the costal border and the iliac crest.</p>
      <p>
        <bold>Biochemical Analysis</bold>
      </p>
      <p>Blood samples were collected in a fasting state. Insulin was measured via electrochemiluminescence (Roche, Switzerland), and ultra-sensitive plasma C-reactive protein (us-CRP) was measured via immunonephelometry (Roche, Switzerland). The lipid profile was enzymatically measured (Roche, Switzerland), and the LDL-cholesterol level was calculated according to the Friedewald formula whenever the triglycerides were below 400 mg/dL. The homeostasis model assessment for insulin resistance (HOMA-IR) was performed to determine insulin resistance<sup>13</sup>. The coefficients of variation for these parameters were all below 6%.</p>
      <p>
        <bold>Echocardiographic Study</bold>
      </p>
      <p>Images were obtained with an EnVisor C HD ultrasound system (Philips Medical, Andover, MA, USA) equipped with a 4 to 2 MHz sectorial transducer. The cine loops and static images were digitally recorded, including the M-mode, 2-dimensional, and Doppler modalities. Images were read off-line in a dedicated workstation (ComPACS, Medimatic Srl, Italy) by a single investigator.</p>
      <p>The left ventricle (LV) internal dimension, septum and posterior wall thicknesses were measured from the parasternal longitudinal two-dimensional image. The left atrial volume index (LAVi) was measured at the end-ventricular systole from the apical 4-chamber view, using the simple Simpson's rule and indexed to the body surface area.</p>
      <p>The diastolic function was evaluated from the mitral inflow Doppler<sup>14</sup> and tissue Doppler<sup>15</sup> measurements, including: mitral inflow early (E wave) and late (A wave) diastolic velocities, deceleration time (DT) of early diastolic velocity, and early (E' wave) and late (A' wave) diastolic annular velocities assessed at the septal mitral anulus. The E/A ratio and the E/E' ratio were calculated from previous parameters.</p>
      <p>All measurements and definitions of relevant cut-offs followed the American Society of Echocardiography recommendations; all of the data were an average of up to 3 consecutive cardiac cycles<sup>16,17</sup>. Left ventricle volume and ejection fraction were calculated using the Teichholz formula. Left ventricle mass index (LVMI) was calculated according to the American Society Echocardiography formula (16) and indexed to the body height to the power of 2.7<sup>18</sup>. Relative wall thickness (RWT) was defined as (septum + posterior wall thickness)/LV diastolic diameter. The intra-reader reproducibility was assessed in 16 participants as a coefficient of variation (CV) and intra-class correlation (ICC), which were, respectively, E' wave (CV: 5.2% and ICC: 0,99;95%CI: 0.97-0.99), E wave (CV 4.5% and ICC: 0.98; IC95% 0.96-0.99) and A wave (CV 3.5% and ICC: 0.98;IC95% 0.97-0.99). Additionally, for the two-dimensional measurements, CVs ranged between 8% and 13% and ICCs were above 0.75, whose values are similar to those described in previous studies<sup>19,20</sup>.</p>
      <p>
        <bold>ELISA Assays</bold>
      </p>
      <p>Fasting venous blood samples (15 mL) were collected in ethylenediamine tetraacetic acid-containing tubes. Samples were immediately centrifuged at 4&#186;C at 3,000 x g for 20 min, and the plasma removed and stored at -70&#186;C. The plasma samples were all blinded analyzed simultaneously by a laboratory technician. MMP9 and TIMP1 levels were measured in duplicate using commercially available ELISA kits (R &amp; D Systems, Minneapolis, MN, USA). The MMP9 assay sensitivity was &lt;0.156 ng/mL, and the TIMP1 assay sensitivity was &lt;0.08 ng/mL; the intra- and inter-assay coefficients of variation were 6% and 10%, respectively. The NT-proBNP level was also measured with a commercial ELISA kit (Roche Diagnostic, France). The NT-proBNP assay sensitivity was &lt;0.6 pmol/L with intra- and inter-assay coefficients of variation of 1.9% and 3.1%, respectively.</p>
      <p>
        <bold>Statistical Analysis</bold>
      </p>
      <p>Results are expressed as mean and SD, or as percentage. Groups were compared with a Chi-square or independent Student's <italic>t</italic> test analysis. The associations between continuous variables were tested with Pearson correlation coefficient. Multivariable linear regression analyses models were performed to identify which variables were independently associated with the presence of the MS.</p>
      <p>We calculated a sample size of 66 MS and 33 CTR, considering an alpha value of 0.05, a power of 0.8 and 0.6 standard deviation of difference in MMP9 levels between groups. This value was estimated based on MMP9 differences described by Tayebjee et al<sup>21 </sup>- between hypertensive patients - which frequently showed diastolic dysfunction - and normal controls. P values &lt;0.05 were considered to be statistically significant. All of the statistical analyses were performed with the SPSS software package (SPSS 15.0 Inc., USA).</p>
      <p>
        <bold>Results</bold>
      </p>
      <p>We studied 76 patients in the MS group (43.3 &#144;&#177; 7.9 years, 65% male), and 30 healthy controls (CTR; 40.9 &#144;&#177; 6.6 years, 63% male). Further clinical characteristics and laboratory parameters of the groups are shown in <xref ref-type="table" rid="en_aop_5302tab01-body2">Table 1</xref>. The MS group, as expected, had increased weight, waist circumference, heart rate, blood pressure, and cholesterol levels when compared with the CTR group.</p>
      <p content-type="asset">
        <table-wrap id="en_aop_5302tab01-body2">
          <graphic xlink:href="1678-4170-abc-101-04-0311-30182-gt01-en.jpg"/></table-wrap>
      </p>
      <p>Left ventricular mass index was higher in the MS group (<xref ref-type="table" rid="en_aop_5302tab02-body2">Table 2</xref>). Left atrial volume index and ejection fraction did not differ between groups.</p>
      <p content-type="asset">
        <table-wrap id="en_aop_5302tab02-body2">
          <graphic xlink:href="1678-4170-abc-101-04-0311-30182-gt02-en.jpg"/></table-wrap>
      </p>
      <p>The diastolic function parameters showed that MS had higher A wave (63.4 &#144;&#177; 14.1 cm/s vs. 53.1 &#144;&#177; 8.9 cm/s; p &lt; 0.001), and lower E' wave (10.1 &#144;&#177; 3.0 cm/s vs. 11.9 &#144;&#177; 2.6 cm/s; p = 0.005) compared with controls, but with mean values within the normality range<sup>17</sup>. These differences resulted in a reduced E/A ratio (p = 0.05) and an increased E/E' ratio (p &lt; 0.001) in the MS group. E wave (p = 0.45) and deceleration time (p = 0.98) did not differ between the groups (<xref ref-type="table" rid="en_aop_5302tab02-body2">Table 2</xref>).</p>
      <p>Extracellular matrix activity biomarkers showed that MMP9 levels were higher in the MS group (502.9 &#144;&#177; 237.1 ng / mL vs. 330.4 &#144;&#177; 162.7 ng/mL; p &lt; 0.001), but with no differences in TIMP1 (210.2 &#144;&#177; 55.6 ng/mL vs 220.2 &#144;&#177; 57.2 ng/mL; p = 0.41) levels (<xref ref-type="fig" rid="en_aop_5302fig01-body2">Figure 1</xref>). Insulin resistance measured by HOMA-IR (p &lt; 0.001) and us-CRP (p = 0.001) levels were higher in the MS group, while NT-proBNP levels (p = 0.19) did not show statistically significant difference between the groups (<xref ref-type="table" rid="en_aop_5303tab03-body2">Table 3</xref>).</p>
      <p content-type="asset">
        <fig id="en_aop_5302fig01-body2">
          <graphic xlink:href="1678-4170-abc-101-04-0311-30182-gf01-en.jpg"/></fig>
      </p>
      <p content-type="asset">
        <table-wrap id="en_aop_5303tab03-body2">
          <graphic xlink:href="1678-4170-abc-101-04-0311-30182-gt03-en.jpg"/></table-wrap>
      </p>
      <p>In a multiple linear regression, we investigated the independent associations of blood pressure, BMI, waist circumference, HDL-cholesterol, triglyceride, HOMA-IR, us-CRP, MMP9, TIMP1, NT-proBNP, E wave, A wave, E' wave, and A' wave with MS. Only MMP9 (&#946; = 0.13, p = 0.03) was independently associated to MS.</p>
      <p>
        <bold>Discussion</bold>
      </p>
      <p>In this study, the MS group showed difference in diastolic function parameters and higher levels of HOMA-IR, us-CRP and MMP9 when compared to healthy controls, with no difference in TIMP1 and NT-proBNP levels. However, when adjusted for covariates, only MMP9 was independently associated with the MS.</p>
      <p>De las Fuentes et al<sup>4</sup>, investigating echocardiographic parameters of diastolic function in MS patients, showed increased A wave, decreased E' wave, and no difference in E wave. Although we have found similar results for these parameters, they were not independently associated with MS after adjustment for covariates, whereas MMP9 was still significant. We could infer that, in the early phases of metabolic syndrome, modulations in ECM activity measured by the increase in MMP9 levels, anticipate measurable changes in cardiac pressures measured by diastolic Doppler parameters, NT- proBNP levels or left atrial dimensions, which are frequently used as surrogate markers of loading conditions<sup>22,23</sup>.</p>
      <p>Extracellular matrix activity has been associated with relaxation and LV stiffness<sup>9</sup>. The increased MMP9 in the metabolic syndrome may represent a collagen turnover state in the extracellular matrix, which may contribute to adverse ventricular remodeling and left ventricular stiffness. Gon&#231;alves et al<sup>24</sup>, studying 25 patients with MS and 25 healthy controls, found increased levels of both MMP9 and TIMP1 in the MS group; reflecting the advanced dysmetabolic state in those patients compared to our sample.</p>
      <p>Oversimplification of multifactorial mechanisms based upon a limited subset of markers is inherent to this study design and precludes causal inferences. A potential bias of this analysis was the non-blinded echocardiographic acquisition for the groups, minimized by the off-line reading by a single investigator. It must also be brought to attention the potential role of newer technologies, such as the speckle tracking, which could more accurately find these early adaptive changes related to the metabolic syndrome.</p>
      <p>
        <bold>Conclusions</bold>
      </p>
      <p>We have found that patients with MS showed differences in echocardiographic measures of diastolic function, in ECM activity measured by MMP9, us-CRP and HOMA-IR when compared to healthy controls. However, only MMP9 was independently associated with the MS. These findings suggest that there are early effects on extracellular matrix activity in metabolic syndrome, which cannot be tracked by routine echocardiographic measures of diastolic function.</p>
      <p>
        <bold>Author contributions</bold>
      </p>
      <p>Conception and design of the research: Santos ABS, Junges M, Silvello D, Macari A, Ara&#250;jo BS, Seligman BG, Duncan BB, Clausell N, Foppa M; Acquisition of data: Santos ABS, Junges M, Silvello D, Macari A, Ara&#250;jo BS, Seligman BG, Foppa M; Analysis and interpretation of the data: Santos ABS, Junges M, Silvello D, Seligman BG, Rohde LEP, Clausell N, Foppa M; Statistical analysis: Santos ABS, Foppa M; Obtaining funding: Santos ABS, Duncan BB, Foppa M; Writing of the manuscript: Santos ABS, Seligman BG, Duncan BB, Clausell N, Foppa M; Critical revision of the manuscript for intellectual content: Santos ABS, Seligman BG, Duncan BB, Rohde LEP, Clausell N, Foppa M.</p>
      <p>
        <bold>Potential Conflict of Interest</bold>
      </p>
      <p>No potential conflict of interest relevant to this article was reported.</p>
      <p>
        <bold>Sources of Funding</bold>
      </p>
      <p>This study was funded by CNPq and FIPE/HCPA.</p>
      <p>
        <bold>Study Association</bold>
      </p>
      <p>This article is part of the thesis of master submitted by Angela Barreto Santiago Santos from Universidade Federal do Rio Grande do Sul.</p>
      <p>
        <bold>References</bold>
      </p>
    </body>
  </sub-article>
</article>
