In most cases, atherosclerotic cardiovascular disease (ACVD) is preventable through primary prevention and control of traditional risk factors. Smoking cessation, regular physical activity, and adherence to healthy dietary patterns, such as a diet rich in fruits and vegetables and low in salt, may decrease the risk of ACVD. ¹ Moreover, healthy dietary habits include the consumption of fish, vegetables, and poultry as the main protein sources, combined with decreased intake of trans fats, added sugar, red meats, sodium, and saturated fatty acids. ² Even in patients with established ACVD, adherence to nutritional treatment that improves diet quality can provide numerous health benefits. ³

The assessment of diet quality of patients with or at risk of ACVD has been important for dietary intervention. ³ The Revised Diet Quality Index (IQD-R) was developed for the Brazilian population ⁴ and is used to simultaneously analyze several components of the diet, considering energy density and quality, regardless of the amount of food consumed. A population-based study conducted in São Paulo ⁵ showed significant differences in IQD-R between adult men and women. Furthermore, it demonstrated that some sociodemographic and lifestyle factors can affect the quality of diet. The same research group showed the need to improve the quality of the diet of the elderly population and highlighted that some factors, such as physical activity and diabetes, may be correlated with better IQD-R scores. ⁶

Recently, our group showed that Brazilian patients with ACVD who consume sugary drinks had higher body mass index (BMI), waist circumference (WC), and serum triglyceride levels, which are important risk factors for ACVD. ⁷ It has also been shown that patients with ACVD in the southern region of Brazil consume more sodium than recommended. ⁸ Our group also demonstrated that more than 80% of patients with ACVD from Pelotas/RS had metabolic syndrome, ⁹ and the food groups with the highest energy contribution to their diets were meats, cereals, breads, and sweets. ¹⁰ The present study aimed to evaluate dietary quality of ACVD patients and associated clinical factors.

This is a cross-sectional substudy of a randomized clinical trial entitled “ Efeito do Programa Alimentar Brasileiro Cardioprotetor (DICA Br) na redução de eventos e fatores de risco na prevenção secundária para doença cardiovascular: Um Ensaio Clínico Randomizado ”, ¹¹ coordinated by the Hospital do Coração de São Paulo (HCor) in partnership with the national program for support and development of the Brazilian Unified Health System ( Programa de Apoio ao Desenvolvimento Institucional do Sistema Único de Saúde , PROADI-SUS). The data presented refer to patients from a collaborating center in the HCor and were collected from August 2013 to December 2014.

Eighty patients were included in the study, of whom 76 patients were assessed for economic level and education. Mean age of patients was 60 years; most patients were male, had a low socioeconomic status, elementary education, and had hypertension, dyslipidemia, increased WC, and were overweight ( Table 1 ).

Table 1

Variable	N (%)
Sex
Male	53 (66.25)
Female	27 (33.75)
Age
Adults	38 (47.50)
Elderly individuals	42 (52.50)
Socioeconomic status *
A/B	13 (17.11)
C	51 (67.10)
D/E	12 (15.79)
Education*
Illiterate	20 (26.32)
Elementary school	47 (61.84)
High school	7 (9.21)
College	2 (2.63)
Current smoking
No	68 (85.00)
Yes	12 (15.00)
Nutritional status (BMI)
Underweight	3 (3.75)
Normal weight	18 (22.50)
Overweight	27 (33.75)
Obesity	32 (40.00)
Abdominal obesity
No	13 (16.25)
Yes	67 (83.75)
Hypertension
No	17 (21.25)
Yes	63 (78.75)
Diabetes
No	50 (62.50)
Yes	30 (37.50)
Dyslipidemia
No	33 (41.25)
Yes	47 (58.75)

* Four patients with missing data; BMI: body mass index

The average global IQD-R score was 56.70 ± 12.56 points, ranging from 25.00 to 78.70 points. The IQD-R items with the lowest scores were “whole grains,” “dark green and orange vegetables,” “total fruits,” and “whole fruits,” and those with the highest scores were “meats, eggs and pulses” and “total cereals” ( Table 2 ). Approximately 80% of patients scored zero for “whole grains,” and 50% of patients scored zero for “whole fruits,” and “dark green and orange vegetables.”

Table 2

IQD-R components	Highest score	Mean (points)	Standard deviation
Total fruits	5	0.55	1.41
Whole fruits	5	2.47	2.41
Total vegetables	5	3.16	2.15
Dark green and orange vegetables	5	2.44	2.48
Total cereals	5	4.28	1.21
Whole grains	5	0.98	1.81
Milk and dairy products	10	4.20	3.56
Meats, eggs, and pulses	10	8.53	2.57
Oils	10	6.20	2.68
Saturated fat	10	7.35	2.97
Sodium	10	3.63	3.10
Gord_AA	20	12.71	7.10
Total IQD-R	100	56.70	12.56

Gord_AA: calories from solid fats (saturated and trans fats), alcohol, and added sugar; IQD-R: Revised Diet Quality Index

As shown in Table 3 , patients with diabetes presented significantly higher IQD-R scores than those without diabetes (61.14 versus 53.97 points; p = 0.014). Of the patients with diabetes, 23 had hypertension, 20 had dyslipidemia, and 17 had both hypertension and dyslipidemia. There was no statistical difference in IQD-R score (data not shown) or in any of the other variables analyzed between patients with and without diabetes.

Table 3

Variables	Mean	Standard deviation	p
Sex			0.386*
Male	54.92	13.28
Female	57.54	12.46
Age			0.549*
Adults	55.75	13.28
Elderly individuals	57.47	12.30
Economic levels			0.608†
A/B	59.62	14.60
C	56.78	12.30
D/E	54.51	13.07
Education			0.143†
Illiterate	57.77	10.55
Elementary/high school	55.97	13.33
College	73.76	1.12
Current smoking			0.229*
No	57.38	12.57
Yes	52.57	13.34
Hypertension			0.732*
No	55.71	13.81
Yes	56.91	12.52
Diabetes			0.014*
No	53.97	12.58
Yes	61.14	11.83
Dyslipidemia			0.484*
No	55.46	11.85
Yes	57.50	13.36

*Student’s t-test; †ANOVA; IQD-R: Revised Diet Quality Index

The main finding of this study was that patients with ACVD with diabetes had higher IQD-R scores than those without diabetes. This result corroborates the findings of another population-based study conducted in Campinas, Brazil, which found a higher diet quality score among elderly patients with diabetes compared to those who did not have the comorbidity. ⁶ In Australia, a survey on 9,435 adults ¹⁸ used a diet quality index similar to that of the IQD-R and found better diet quality among patients with diabetes. In North America, another population-based study, which included 4,356 adults, highlighted better quality of diet in patients with chronic disease compared to healthy individuals. ¹⁹ However, a study on 295 elderly individuals from São Caetano, Brazil, who were users of public health centers, did not detect a significant difference in IQD-R scores between patients with and without diabetes. ²⁰

A better diet quality can decrease mortality risk by 40% and prolong life expectancy by 2.5 years in elderly patients with cardiovascular disease. ²¹ However, this association was not statistically significant in healthy subjects. Moreover, a higher diet quality score was found in elderly patients with cardiovascular disease than in healthy elderly individuals. ²¹ These findings were attributed to the fact that 17% of healthy elderly patients versus more than half (54%) of the elderly patients with cardiovascular disease followed a prescribed eating plan. In our sample, all patients had cardiovascular disease; however, when stratified by the presence or absence of diabetes, there was a difference in diet quality. This suggests that cardiovascular disease patients with diabetes are more concerned about their diet, especially due to glycemic control, and that they had even received dietary advice. However, this information was not analyzed in this study.

Another relevant finding of the current study was the global IQD-R score, which was 56 points. Although there is no cutoff point, it is valid to compare the scores obtained from other samples. A study ⁴ with 949 adults (mean age of 37 years), conducted in Sao Paulo, Brazil, showed an overall IQD-R score of 52.7, which was significantly higher in women. Our sample consisted of older patients (mean age of 60 years), who showed a slightly higher IQD-R score. Furthermore, we found no significant differences between sexes. Another survey ⁶ also conducted in Sao Paulo, Brazil, whose sample consisted of 1,509 elderly individuals with a mean age of 69.9 years, showed a higher IQD-R score (62.4 points) than our study. In this same study, ⁶ the IQD-R items with the lowest scores were “whole grains,” “sodium,” “milk and dairy products,” “total fruits,” and “whole fruits,” which was similar to our results. The items with the lowest contributions to the IQD-R score were “whole grains,” “dark green and orange vegetables,” “pulses,” “total fruits,” and “whole fruits.”

A Swedish survey ²² that enrolled more than 17,000 individuals aged 44–74 years concluded that a dietary pattern rich in fiber, fruits, and vegetables (> 400 g/day) was associated with a decrease in cardiovascular events in both men and women. In the present study, we found a low consumption of these food groups, and half of the sample did not consume these foods daily. These data corroborate the food intake pattern in the Brazilian population, evaluated in 27 cities in Brazil by the Surveillance System for Risk and Protective Factors for Chronic Diseases by Telephone Survey (VIGITEL 2018). ²³ The survey revealed that only 23% of the sample consumed the recommended servings of fruits and vegetables, and that consumption was lower in men (18.4%) than in women (27.2%). ²³

Another component worth mentioning is sodium. In the present study, most patients had hypertension and a high consumption of sodium, and only 1.2% of participants reached the maximum daily recommendation of up to 2 g/day. ²⁴ However, approximately 60% of patients reached the recommendations for “meat, eggs, and pulses” and “total cereals,” with the highest scores. It is important to emphasize that IQD-R adds pulses to the meat group, and this may contribute to a high score for this component, since the consumption of beans is part of the traditional Brazilian culture. Moreover, it is important to consider the high consumption of meat in the state of Rio Grande do Sul, as confirmed by a study conducted in Pelotas, where 99.1% of adults reported having consumed some type of meat in the past year and approximately 32% reported daily meat consumption. ²⁵

We did not find an association between diet quality and sociodemographic variables, such as age, sex, purchasing power, and education, corroborating the results of other studies on the elderly population. ^{6 , 20} There was also no association between diet quality and smoking, which is different from other studies. ^{6 , 18}

The main limitation of this study was the sample size. Furthermore, the method used to assess food consumption may not reflect habitual consumption because it was applied in only one day. Despite these limitations, the present study is one of the first to assess diet quality of cardiovascular disease patients using the IQD-R in Brazil, thus contributing to a better understanding of the dietary pattern of this population, which can guide future nutritional interventions.

Based on the IQD-R results obtained in this study, there is a need to improve diet quality among ACVD patients in Brazil, especially regarding the consumption of fiber, fruits, and vegetables, in addition to reducing sodium consumption. Patients with cardiovascular disease and diabetes had better diet quality than those without diabetes. No association was found between diet quality score and other factors tested. More studies that provide additional details of dietary patterns of ACVD patients are needed to guide more specific dietary interventions.