Body Adiposity and Endothelial Dysfunction Assessed By Laser Speckle Contrast Imaging in Obese and Overweight Individuals With Suboptimal Vitamin D Status: Sex Differences

Abstract

Background:

Low Vitamin D levels are prevalent in obesity and have been linked to adverse cardiovascular and metabolic outcomes.

Objective:

This cross-sectional study aimed to assess anthropometric indices, vascular, autonomic function in obese and overweight individuals with suboptimal vitamin D status.

Methods:

Participants of both sexes, 40-69 years, Body Mass Index (BMI) 25-40 kg/m², were divided into two groups above and under the median vitamin D level (22,6 ng/ml), named Suboptimal (SUB-D) and Lower (LOW-D) vitamin D, respectively. Vascular function was assessed using central hemodynamic parameters (Mobil-O-Graph®), endothelial function (microvascular reactivity; Laser Speckle Contrast Image system), and heart rate variability (Polar® monitor). The groups were compared using an unpaired Student’s t-test, and p-values < 0,05 were considered statistically significant.

Results:

The groups (n = 90) had similar ages and blood pressures. The LOW-D group had a higher body fat percentage (%BF; 29 ± 4 vs. 33 ± 3, p = 0.020) and glycated Hb (5.4 ± 0.4 vs. 5.8 ± 0.4, p = 0.029) in males. Females had higher Visceral Adiposity Index (VAI; 2.33 ± 0.86 vs. 3.32 ± 1.86, p = 0.008) and Lipid Accumulation Products (LAP; 39 ± 23 vs. 63 ± 40, p = 0.005). The LOW-D group showed a lower percentage increase in the area under the curve in post-occlusive reactive hyperemia (%AUC-PORH) (70 ± 30 vs. 55 ± 32%, p = 0.034). Females showed inverse correlation of vitamin D levels and VAI and LAP, and a positive correlation with %AUC-PORH.

Conclusions:

In obese and overweight individuals, lower vitamin D content was associated with higher levels of body adiposity in males. Furthermore, impaired metabolic functions and endothelial dysfunction were related to lower vitamin D levels in females, as in the central illustration.