Association of body composition with bone mineral density and fractures in Chinese male type 2 diabetes mellitus

The association between body composition and bone health in men over 50 years with type 2 diabetes mellitus remains unclear. We aimed to investigate how fat and lean mass affect bone health in male patients with diabetes over 50 years. A total of 233 hospitalized male type 2 diabetes mellitus patients with aged 50 to 78 years were enrolled. Lean mass, fat mass and bone mineral density (BMD) were estimated. The clinical fractures were also assessed. Glycosylated hemoglobin, bone turnover markers, and biochemical parameters were measured. The normal BMD group had a higher lean mass index (LMI) and fat mass index (FMI) and lower levels of bone turnover markers. glycosylated hemoglobin was negatively correlated with LMI (r = -0.224, P = .001) and FMI (r = -0.158, P = .02). In partial correlation adjusted for age and body weight, FMI was negatively correlated (r = -0.135, P = .045) with lumbar spine, while LMI was still positively correlated with lumbar spine (R = 0.133, P = .048) and total hip (R = 0.145, P = .031). In multiple regression analysis, LMI was consistently associated with BMD at the spine (beta = 0.290, P < .01), hip (beta = 0.293, P < .01), and femoral neck (beta = 0.210, P = .01), whereas FMI was only positively associated with BMD at the femoral neck (beta = 0.162, P = .037). A total of 28 patients diagnosed with diabetic osteoporotic fractures had lower LMI and FMI than their non-fractured counterparts. LMI was negatively associated with fracture, whereas FMI had such an effect only before adjusting for BMD. Lean mass is dominant in maintaining BMD and is a BMD-independent protective factor for diabetic osteoporotic fracture in male patients aged over 50 years. Fat mass in gravity is positively associated with BMD in the femoral neck, which may mediate fracture protection.