Vit D is a determinant of muscle mass
Posted: Tue Apr 14, 2015 9:51 am
Vitamin D Status is a Determinant of Skeletal Muscle Mass in Obesity according to the Body Fat Percentages
Background
Vitamin D deficiency is now being recognized as an emerging problem worldwide. Obesity has been found to be associated with lower serum 25-hydroxyvitamin D (25(OH)D) concentrations due to various mechanisms. There is increasing evidence showing extra-skeletal health benefit of vitamin D. Previous studies demonstrated the relationship between vitamin D and adiposity. However, the association between vitamin D status and skeletal muscle mass has not been established in healthy obese individuals in tropical countries.
Objectives
This cross-sectional study was designed to assess the vitamin D status and its relationship between serum 25(OH)D concentrations and body composition, including skeletal muscle mass and adiposity in healthy obese non-diabetes subjects who live in Thailand, which is located near the equator.
Results
We enrolled163 Thai obese subjects (59.5% were female). The prevalence of vitamin D deficiency (25(OH)D <20 ng/ml) and vitamin D inadequacy (25(OH)D <30 ng/ml) were 49/163 (30.1%) and 148/163 (90.8%) respectively. In all, 98% of obese subjects with BMI>35 kg/m2 had vitamin D inadequacy. Serum 25(OH)D concentrations were negatively associated with percent body fat (%BF) (r = - 0.23, P =0.003). Moreover, vitamin D status was positively associated with skeletal muscle mass (SMM) (r = 0.18, P =0.03) and the association still exist after controlling for body fat mass and age (P= 0.003). Interestingly, in the subjects with lowest tertile of %BF, multiple linear regression analysis revealed that the significant positive predictors of %SMM were the vitamin D status and male gender, the negative predictor was the body mass index after adjusting with age and exercise duration.
Conclusions
Our study demonstrated the high prevalence of vitamin D deficiency in obese, non-diabetes Thai populations. Vitamin D status was an independent predictor of %SMM of patients with lowest tertile of %BF. We speculated that adiposity might play a role in the relationship of vitamin D and skeletal muscle mass.
Background
Vitamin D deficiency is now being recognized as an emerging problem worldwide. Obesity has been found to be associated with lower serum 25-hydroxyvitamin D (25(OH)D) concentrations due to various mechanisms. There is increasing evidence showing extra-skeletal health benefit of vitamin D. Previous studies demonstrated the relationship between vitamin D and adiposity. However, the association between vitamin D status and skeletal muscle mass has not been established in healthy obese individuals in tropical countries.
Objectives
This cross-sectional study was designed to assess the vitamin D status and its relationship between serum 25(OH)D concentrations and body composition, including skeletal muscle mass and adiposity in healthy obese non-diabetes subjects who live in Thailand, which is located near the equator.
Results
We enrolled163 Thai obese subjects (59.5% were female). The prevalence of vitamin D deficiency (25(OH)D <20 ng/ml) and vitamin D inadequacy (25(OH)D <30 ng/ml) were 49/163 (30.1%) and 148/163 (90.8%) respectively. In all, 98% of obese subjects with BMI>35 kg/m2 had vitamin D inadequacy. Serum 25(OH)D concentrations were negatively associated with percent body fat (%BF) (r = - 0.23, P =0.003). Moreover, vitamin D status was positively associated with skeletal muscle mass (SMM) (r = 0.18, P =0.03) and the association still exist after controlling for body fat mass and age (P= 0.003). Interestingly, in the subjects with lowest tertile of %BF, multiple linear regression analysis revealed that the significant positive predictors of %SMM were the vitamin D status and male gender, the negative predictor was the body mass index after adjusting with age and exercise duration.
Conclusions
Our study demonstrated the high prevalence of vitamin D deficiency in obese, non-diabetes Thai populations. Vitamin D status was an independent predictor of %SMM of patients with lowest tertile of %BF. We speculated that adiposity might play a role in the relationship of vitamin D and skeletal muscle mass.