High blood pressure (HBP) is the main preventable risk factor for morbidity and mortality from cardiovascular causes in the world. It has a more unfavorable impact on low- and middle-income countries.¹ The global estimate of hypertension for 2019 among individuals aged 30 to 79 years was 626 million cases among women and 652 million among men,² with a prevalence of 32% and 34%, respectively.² In Brazil, the National Health Survey from 2019 estimated HBP self-reported prevalence at 23.9%: 2.29% in individuals 18-24 years old, 7.25% in individuals 25-39 years old, 27.21% in individuals 40-59 years old, and 54,99% in individuals over 60 years old.³ In Spain, the IBERICAN cohort study has found a prevalence of 1.5% of hypertensive individuals under 40 years old, 7.1% in individuals 40-49 years old, 20.5% in individuals 50-59 years old, 31.2 in individuals 60-69 years old, 30.7% in individuals 70-79 years old, and 9.0% in individuals over 80 years old.⁴

HBP prevention can be achieved both through initiatives by individuals and public health interventions.^1,5 In the first case, lifestyle changes are important for preventing and treating hypertension,⁶ bringing to light the role of lifestyle medicine (LM) in the care of hypertensive patients. LM is an evidence-based medical specialty⁷ that proposes health interventions in primary and secondary prevention to reduce the impact of chronic diseases.^7,8 The domains assessed by LM are diet, physical activity, substance use, sleep, social support, stress management, and environmental exposure. Lifestyle habits are assessed in a multidimensional way,^7,9–12 and the main risk factors for hypertension and cardiovascular mortality are directly related to these domains. The Lancet Commission on Hypertension cites a healthy diet, physical activity, weight loss, stress management, and a reduction in alcohol consumption and smoking as key measures to prevent and treat hypertension.¹

In 2020, due to social isolation, the world population changed behavior patterns associated with lifestyle, such as diet, physical activity, and sleep. Some studies have shown a reduction in physical activity,¹³ worsening in eating habits¹⁴ and in sleep quality,¹⁵ increased screen time and alcohol and tobacco use,^15–17 as well as increased cases of depression and anxiety.¹⁵ On the other hand, certain studies have shown improvements in workout¹⁸ and in the quality of family relationships.¹⁵ Evidence is controversial when concluding about the consequences of these behaviors, even if temporary, on HBP.^5,19 In this context, the purpose of this study was to analyze the association between lifestyle and HBP during the first year of the COVID-19 pandemic in Brazil and Spain. In a previous work, we found that the lifestyles in Spain and Brazil are different and that Brazilians had a worse lifestyle.²⁰

A total of 5224 individuals responded to the survey, 1590 in Brazil and 3634 in Spain. We analyzed data from 5216 individuals (99.8% of the total), who responded about the HBP diagnosis. Most participants (76.2%) were female and 66.9% had finished higher education. When analyzing age ranges, we found that 38.3% were between 18 and 39 years old, 45.4% were between 40 and 59 years old, and 16.2% were over 60 years old. Table 1 shows the sociodemographic characteristics, alcohol and substance use, and comorbidities stratified by country. Brazil displayed higher frequencies of women, individuals over 60 years, overweight and obesity, alcohol abuse, depression, and anxiety as compared to Spain (p<0.001).

The overall self-reported HBP prevalence was 19.6% (in Brazil) and 9.2% (in Spain). Table 2 displays the sociodemographic characteristics, according to the HBP diagnosis and stratified by country.

Scores from the SMILE-C scale, including its domains, according to the previous diagnosis of HBP and stratified by country, are found in Table 3. Overall, lifestyle was better (higher SMILE-C scores) in Spain as compared to Brazil. Among the Brazilian population, no statistically significant differences were found in the general lifestyle score, according to the diagnosis of hypertension. Among the Spanish population, we did find a statistically significant better lifestyle score among hypertense individuals (p < 0.001). When observing the results by domains, individuals with HBP had lower SMILE-C scores (worse lifestyle) in the physical activity (p < 0.05) and sleep (p < 0.05) domains in Brazil and higher SMILE-C scores (better lifestyle) in the diet in Spain (p < 0.001). Environmental exposure was better among people with HBP in both countries (p < 0.001).

The results of the adjusted logistic models (Tables 4 and 5) showed that the factors associated with a higher likelihood of self-reported HBP were: living in Brazil, male gender, older age, lower educational attainment, self-reported diagnosis of diabetes, and BMI greater than or equal to 25 (overweight or obesity). Regarding lifestyle, a better lifestyle was associated with a decreased likelihood of HBP (p = 0.034), but scores by domains did not show significant associations. The supplementary tables show that the association of education and lifestyle with HBP was only statistically significant in Brazil. We present a summary of our main results in the Central Illustration.

In our study, approximately twice as many Brazilians as Spanish people reported hypertension diagnosis or treatment (19.60% vs. 9.22%, respectively). The prevalence of risk factors for HBP (such as overweight/obesity and alcohol abuse) was also higher in Brazil, while the lifestyle score was worse. After adjusting for confounding, male and older individuals living in Brazil, with lower educational attainment and worse lifestyles, were more likely to report HBP.

Hypertension prevalence was lower than that estimated by the WHO,² 40.0% - 50.0% in Brazil and 20.0% - 40.0% in Spain (probably because the WHO estimates refer to individuals between 30 and 79 years old).² However, our results from Brazil are similar to the ones found in the National Health Survey,³ and rates in Spain were similar to the IBERICAN cohort in some age ranges.⁴ These numbers provide some evidence that, although our sample was not probabilistic, our results are still comparable to those that were collected using a similar question. It is worth noting that the HBP may still be underestimated in our study because it was not objectively measured, and some individuals may not be aware of their diagnosis.

We observed a huge difference in the frequencies of risk factors for HBP between the countries. Obesity prevalence in Brazil was twice the obesity prevalence in Spain, for instance, which is similar to results from other studies.^24,25 Those differences likely reflect cultural habits, as well as socioeconomic and environmental factors that have a role in obesity epidemics. Regarding cultural habits, it is important to highlight the differences in dietary patterns among countries, since diet is one of the key factors for the primary and secondary prevention of hypertension.^26,27 We found that the SMILE-C diet score was better in Spain, which may reflect the historical adherence to the Mediterranean diet in the country. The Mediterranean diet has been studied as a tool for HBP²⁸ and cardiovascular disease²⁹ prevention since the late 1990s and is recommended for the prevention and management of HBP. Other studies have also identified improvements in dietary habits of some populations during the pandemic period,^13,30,31 including in Spain,³² and an increased adherence to the Mediterranean diet during the pandemic.³²

Diet, however, is only one of the seven lifestyle domains evaluated by the SMILE-C. We found that the multidimensional evaluation of lifestyle was better in Spain and was an independent protective factor associated with HBP. There are many factors associated with better lifestyle behaviors, including demographic and socioeconomic factors. Thus, some of the differences observed in lifestyle between the countries may be due to the differences in those characteristics of the samples. For instance, older individuals often exhibit better lifestyle behaviors, such as healthier diets and increased compliance with health promotion activities, although they may also show higher physical inactivity.^33,34 Men are more likely to engage in physical activity, while women tend to have better dietary habits and lower rates of smoking and alcohol consumption. Besides, higher education and higher income are associated with increased physical activity, better dietary habits, lower alcohol and tobacco use and more frequent health check-ups.³⁵

Social determinants of health and social disparity may also influence lifestyle. In a 2021 study, Zhou et al. argued hypertension patterns must be analyzed differently between high-income and middle- and low-income countries because the two groups have, for instance, different access to fresh diet and low-sodium diet, hence different factors causing hypertension trends.⁵ Urban violence might discourage individuals from working out outdoors, increasing sedentarism and obesity. Food insecurity and the burden of malnutrition are also of particular interest.³⁶ Considering that lifestyle is directly correlated with HBP in our study, promoting strategies to improve lifestyle may be an important step for primary and secondary hypertension prevention.

The limitations of this study encompass the non-probabilistic nature of the sample, which generates a selection bias (including more individuals with higher education and women), and results may not be extended to the entire population; the nature of data collection, which excludes individuals without access to the Internet and, therefore, represents a vulnerable portion of the population (in Brazil, around 19% of the population aged >10 years does not have Internet access).³⁷ The third limitation is the use of self-reported measures, which may underestimate the HBP prevalence, given the lack of knowledge about the diagnosis itself. Finally, this is a cross-sectional study and, therefore, does not allow inferring causality.

Our data reinforce the importance of primary and secondary prevention in the population strategy to combat hypertension, where LM can be a useful tool. In this sense, health professionals must be familiar with the main lifestyle domains to implement habit change strategies.