Níveis séricos de vitamina D em mulheres com obesidade grave : prevalência de deficiência e fatores associados

Abstract

Vitamin D has several functions in the body having a fundamental role in bone mineralization. Deficiency of this vitamin is frequent in the general population and especially in obese people. Its serum levels are inversely associated with body mass index and fat mass, however, factors associated with the levels of this micronutrient in severely obese women have not yet been studied. The objectives of this study were: to identify deficiency and to assess factors associated with serum vitamin D levels in women with severe obesity. This is a baseline study of a randomized clinical trial entitled “DietBra Trial”, carried out at a Public Hospital in the city of Goiânia - Goiás. Data collection was carried out from June 2015 to February 2016, from in which 128 women with severe obesity participated (body mass index - BMI: ≥ 35 kg / m²). Sociodemographic variables were collected regarding sun exposure, food consumption, clinical conditions and body composition, performed with (DXA). For the classification of vitamin D, <20 ng / nml was considered as deficiency. The outcome variable was serum vitamin D in ng / ml. To check the associations between exposure variables and serum vitamin D level, linear regression was used. Those with p <0.20 in the simple regression were selected for the multiple. P <0,05 was considered significant. The prevalence of women with disabilities was 14.1% (n = 18). Regarding the degree of obesity, vitamin D deficiency was similar between groups. In the bivariate analysis, the age group 40 - 49 years and ≥ 50 years (β: -5,29, p = 0,005; β: -6,27, p=0,014), time of sun / day ≥ 20 min (β: 4,52, p=0,072), use of sunscreen (β: -3.32, p=0,168), inadequate calcium intake (β: -8,84, p=0,030), BMI: 40-49.9 kg / m² (β: 3,53, p=0,192), menopause (β: -4,99, p=0,029) and hypolipidemics (β: 5,16, p=0,150) presented p <0.20. In the final model, the age groups of 40 to 49 years (β: -5,21, p = 0,005), ≥ 50 years of age (β: -6,27, p=0,014), inadequate calcium intake (β : -8.78, p = 0,027) and the use of lipid-lowering drugs (β: 7,43, p=0,031) were associated with serum vitamin D levels. No relationship was found between body composition and serum vitamin D. Being ≥ 40 years old and inadequate calcium intake reduced serum vitamin D levels, and the use of lipid-lowering drugs, in turn, increased them