Concentrações de 25-hidroxivitamina d: fatores associados e relação com níveis pressóricos em idosos hipertensos

Abstract

Hypovitaminosis D has been studied in recent years and has a significant prevalence worldwide in all stages of life, especially in the elderly, which are at greater risk due to their reduced capacity to generate the vitamin D precursor in the skin, change in lifestyle and reduced practice of outdoor physical activity. Vitamin D deficiency has implications for health, among them, the inverse relationship with blood pressure. This study evaluated factors related to the prevalence of inadequate 25-hydroxyvitamin D levels and its relationship with blood pressure in elderly hypertensive patients belonging to Reference Health Centers of the city of Pessoa-PB/BR. A cross-section study was developed, where the following variables were analyzed: 25-hydroxyvitamin D, parathyroid hormone, magnesium, albumin, creatinine, glucose and ionized calcium, as well as blood pressure values, skin type, consumption of foods rich in vitamin D and BMI. For the descriptive statistical analysis of data, absolute distributions, percentages, means and standard deviations were used. Comparison between means of two continuous variables was performed using the Student t-test and for the analysis of variance, one-way ANOVA was used with significance level of p <0.05. The sample consisted of 91 elderly patients with mean age of 69.73 +7.0 years, 89% women and 11% men. The prevalence of vitamin inadequacy (25-hydroxyvitamin D <29 ng / mL) was 33% and in relation to other biochemical parameters, calcium and creatinine were significantly higher in the group of patients with inadequate levels; however, there were no values outside the cutoff point for each parameter in the entire sample. It is noteworthy that in the group of patients with inadequate levels, only 7.7% showed high PTH levels, but not confirming secondary hyperparathyroidism. There was no statistically significant association between skin type (p = 0.96), sun exposure (p = 0.71), permanence or not at home during the day (p = 0.39) and BMI (p = 0.91) with 25-hydroxyvitamin D levels in adequate and inadequate groups. Regarding the consumption of foods containing vitamin D, high fish consumption was positively associated with higher serum 25-hydroxyvitamin D levels (p = 0.006); on the other hand, the consumption of egg, whole milk and skim milk seemed not to influence. Regarding blood pressure, the mean systolic blood pressure was significantly higher (p = 0.03) in elderly patients with inadequate vitamin D levels, which did not occur for diastolic pressure (p = 0.26). It could be concluded that the prevalence of inadequate 25-hydroxyvitamin D levels was high and its relationship with higher systolic pressure levels is worrying. Based on results shown here, the weekly consumption of fish should be encouraged, since it may play a role in the hypertension treatment.