Cross-talk between muscle and bone in postmenopausal women with hypovitaminosis D.

OBJECTIVES

Visceral fat is more harmful than subcutaneous fat. Women with high amounts of visceral fat have an increased risk of metabolic syndrome (MetS), insulin resistance and low level of serum vitamin D.

METHODS

This was a prospective, randomized and controlled study. Postmenopausal women (n = 101) aged 45-70 years were included. The assessed parameters were: body mass index (BMI), waist circumference (WC), 25-hydroxyvitamin D (25-OHD) status, serum insulin and HOMA-IR, bone mineral density, total fat mass, fat mass index (FMI) measured by DXA, and muscle strength.

RESULTS

Significantly lower values of 25-OHD (35.26 ± 1.61 nmol/l) were found in women with MetS compared to those without MetS (47.52 ± 3.47nmol/l) (t = 3.699; p < 0.000). A significant negative correlation was observed between 25-OHD levels and: WC (rhoWC = -0.94; p < 0.004), BMI (rhoBMI = -0.80; p < 0.002), FMI (rhoFMI = -0.31; p < 0.002) and impaired fasting glucose (IFG) (rhoIFG = -0.23; p < 0.001). The percentage of body fat was statistically significantly higher in the group with insufficient 25-OHD (39.6%) and in the group with a deficit of 25-OHD (48.2%), compared with the maximum permitted percentage body fat of 35% for a female (t = -22.63; p < 0.002). The average hand grip strength of these moderately obese participants was 27.4 ± 4.7 kg. It was significantly lower than the normative grip strength for referent range groups (t = -21.65; p < 0.001).

CONCLUSION

A low 25-OHD level in postmenopausal women is associated with high body fat, metabolic syndrome, low muscular strength and osteopenia.