Comparison of anthropometric profile, bone-related parameters, biochemical parameters, functional capacity, and vitamin D status – a study on postmenopausal Malaysian women

Introduction: The optimal level of total 25(OH)D in Malaysian postmenopausal women that is necessary to ameliorate the combined effects of decreased bone mineral and muscle mass, and increase in adiposity, as seen in osteosarcopenic obesity, is unknown. Given that these are common pathologies existing in bone, muscle and excess fat-related disorders, this study investigated the association between body composition, functional capacity and total 25(OH)D levels. Methods: This was a cross-sectional study involving 117 postmenopausal Malaysian women aged 50-88 years. Total 25(OH)D was analysed by chemiluminescent microparticle immunoassay CMIA on Siemens® platforms. Bone mineral was measured by broadband ultrasound attenuation. Functional performance was assessed using modified components of short physical performance battery test. Statistical analysis was performed using the Statistical Package for Social Sciences (SPSS Version 25.0). Results: Overall, 47% women were vitamin D deficient; 3% had none, 22% had one, 65% had two, and 10% had all three adverse body composition indicators (osteosarcopenic obesity). Individuals without any adverse body composition indicator had higher total 25(OH) D (74.7±7.0nmol/L, p=0.004) compared to all the other groups [1 (53.0±3.8nmol/L); 2 (48.7±1.9nmol/L) and 3 (58.3±5.4nmol/L)]. The single inflection point (ROC curve) for total 25(OH)D in predicting osteosarcopenic obesity was 58.9nmol/L. Conclusion: Higher vitamin D levels were associated with lower body fat, enhanced bone quality, and improved functional capacity. Maintaining vitamin D levels above >58.9nmol/L may protect Malaysian postmenopausal women against the combined pathologies of bone, muscle and excess fat.