Vitamin D deficiency is associated with insulin resistance independent of intracellular calcium, dietary calcium and serum levels of parathormone, calcitriol and calcium in premenopausal women (2015)

1 de janeiro de 2015 às 15:15

Autores: Thaís da Silva Ferreira, Tatiana Martins Rocha, Márcia Regina Simas Torres Klein and Antonio Felipe Sanjuliani

Abstract

Background: There is evidence that vitamin D deficiency is associated with increased risk of cardiovascular disease. However, it is not known if this association is independent of dietary calcium, intracellular calcium and
serum levels of parathormone, calcitriol and calcium.

Objectives: To investigate the independent relationship of vitamin D deficiency with insulin resistance, lipid profile, inflammatory status, blood pressure and endothelial function.

Method: Cross-sectional study conducted with 73 healthy Brazilian premenopausal women aged 18 – 50 years. All participants were evaluated for: 25 hydroxyvitamin D serum levels, anthropometric parameters, body
composition, calcium metabolism, insulin resistance, lipoprotein profile, inflammatory status, blood pressure and endothelial function. Endothelial function was assessed by reactive hyperemia index using Endo-PAT 2000®. Women were stratified in two groups: with vitamin D deficiency (25 hydroxyvitamin D < 20 ng/ml; n=12) and without vitamin D deficiency (25 hydroxyvitamin D ≥ 20 ng/ml; n=61).

Results and discussion: Participants with vitamin D deficiency compared with those without deficiency of this vitamin had significantly higher levels of glucose (88.25 ± 3.24 vs. 80.15 ± 1.13 mg/dl), greater HOMA-IR (6.43
± 0.73 vs. 4.42 ± 0.25) and lower reactive hyperemia index (1.68 ± 0.1 vs. 2.17 ± 0.1). After adjustments for confounding factors including age, body mass index, waist circumference, dietary calcium, intracellular calcium and serum levels of parathormone, calcitriol and calcium differences between groups remained significant, regarding glucose and HOMA-IR.

Conclusions: The findings of the present study suggest that vitamin D deficiency is associated with insulin resistance independent of dietary calcium, intracellular calcium and serum levels of parathormone, calcitriol and calcium in healthy premenopausal women.

Keywords: Vitamin D, Insulin resistance, Endothelial function, Glucose, Parathormone