Nível sérico de vitamina D e sua relação com a doença arterial obstrutiva periférica em usuários de um ambulatório de referência para doenças vasculares no Sul do Brasil

Abstract

Vitamin D plays a key role in bone metabolism, besides taking part in many body functions, for instance in the cardiovascular system. Low serum levels of this vitamin can predict the onset of peripheral arterial disease (PAD), a cardiovascular disease caused by atherosclerotic lesions in blood vessels. Evaluate vitamin D serum levels and their relation with PAD among users of a vascular disease outpatient clinic in Southern Brazil. Cross-sectional study with a consecutive sample of 144 individuals of both sexes, aged at least (≥) 40 years, between March 2016 and January 2017. We considered PAD patients those with ankle-brachial index (ABI) ≤ 0.90 or with arterial revascularization. Demographic, socioeconomic, and behavioral variables and comorbidities were obtained through standardized survey. Vitamin D serum level was biochemically assessed and rated as sufficient (≥30 ng/mL), insufficient (>20 a 29 ng/mL) and deficient (<20 ng/mL). A gender layered analysis was performed in the research of vitamin D serum level associated factors. Pearson's chi-square test was used for the bivariate analysis, Mann–Whitney U test for categorical variables, and T test for symmetries on numerical variables. Multiple linear regression was used to evaluate the relation between independent variables and vitamin D serum level and Poisson regression to analyze the association between this vitamin's serum levels and PAD. The participants presented 36.1% (CI95% 28-44) vit D insufficiency and 45.1% (CI95% 36-53) vit D deficiency. Age was inversely associated with vitamin D serum level (β = -0.22; CI95% -0.38; -0.07), while variables like sun exposure (β = 0.49; CI95% 0.13; 0.84) and vitamin D intake (β = 2.92; CI95% 0.84; 5.00) were positively associated. In a gender layered sample, an independent and inverse effect was demonstrated on age, a direct effect – although bordering – on sun exposure on vitamin D serum levels among men, and an independent and direct effect of vitamin D intake on women serum levels of this vitamin. PAD prevalence was 50.7% (CI95% 42-59). After adjustment for PAD, PRs were 1.08 (CI95% 0.66-1.76) for insufficient serum level and 1.57 (CI95% 0.96-2.57) for deficient vitamin D serum level; (p for trend = 0.020). The present study found a high prevalence of vitamin D deficiency among the studied population. The vitamin D associated variables were age and sun exposure among men and vitamin D intake among women. Vitamin D serum level showed an inverse and significant dose-response relationship with PAD. Considering the high prevalence of lower vitamin D serum levels and the different body functions performed by this vitamin, including its effect on PAD, it is important to guide the population towards sun exposure and vitamin D rich food intake adequate.