Correlação entre os níveis séricos de 25- hidroxivitamina D e A espessura médio-intimal carotídea em afrodescendentes habitantes de comunidades quilombolas

Abstract

The role of vitamin D in the regulation of bone metabolism is already well established. However, in recent years, the role of vitamin D in extraskeletal health has been widely explored. In the cardiovascular area, vitamin D deficiency has been independently associated with the occurrence of myocardial infarction, stroke and cardiovascular death. The mechanisms to explain the association between hypovitaminosis D and cardiovascular disease are still not fully understood, and their association with atherosclerosis is postulated. However, studies attempting to correlate hypovitaminosis D with atherosclerosis markers have produced conflicting results, in the same way as small randomized trials of oral supplementation to evaluate intermediate outcomes, so there is currently considerable debate about whether hypovitaminosis D represents a new risk or would be just an inflammatory marker. In the first article, a comprehensive review was made of the role of vitamin D deficiency in the pathogenesis of cardiovascular disease, from basic aspects of its biosynthesis to the results of interventional studies, through its oral supplementation. The second article presents the results of a cross - sectional analysis of 382 individuals living in quilombola communities in Alcântara - MA, participants of the PREVRENAL cohort, presenting at least one cardiovascular risk factor, with a mean age of 57.79 (± 15.3) years and a slight predominance, in which the serum levels of 25-hydroxyvitamin D, the stable circulating form of the vitamin, were correlated with an established marker of subclinical atherosclerosis, carotid intima-media thickness, and other cardiovascular risk factors. Socio-demographic, lifestyle, anthropometric and clinical data were collected and biochemical tests were performed, including the dosage of 25-hydroxyvitamin D by means of the electrochemiluminescence assay. The urinary excretion of albumin was evaluated by means of the albumin / creatinine ratio in an isolated sample of urine. Hypovitaminosis D was defined as serum 25- hydroxyvitamin D levels <30 ng / mL. All participants underwent examination of the common carotid arteries by high-resolution ultrasonography to measure the intimamedia thickness, and the mean of the measurements on both sides was adopted. Serum levels of 25-hydroxyvitamin D were 50.4 (± 13.5) ng / mL, with a low prevalence of hypovitaminosis D (<5%). By simple linear correlation, there was a significant inverse association between 25-hydroxyvitamin D levels and carotid intima-media thickness (r = -0.174, p = 0.001). However, after multiple regression analysis, only the variables male gender, age, smoking, systolic blood pressure, fasting blood glucose and LDL-cholesterol remained significantly associated with carotid intima-media thickness. Levels of 25-hydroxyvitamin D were independently associated positively with HDL-cholesterol and inversely with urinary albumin excretion. In conclusion, in this Afrodescendant population, with a low prevalence of hypovitaminosis D, there was no independent association between serum 25- hydroxyvitamin D levels and carotid intima-media thickness, a finding that contradicts the hypothesis of its antiatherosclerotic role. On the other hand, its positive association with HDL-cholesterol and the inverse association with urinary albumin excretion, also considered as an independent predictor of cardiovascular events, does not allow the exclusion of cardiovascular protection actions of the vitamin in this population profile.