Bone mineral density and its relationship with body mass index in postmenopausal women with type 2 diabetes mellitus in mainland China

Bone mineral density (BMD) and its association with body mass index (BMI) are uncertain in postmenopausal women with type 2 diabetes mellitus (T2DM) in mainland China. This study was performed to assess this association including 1,042 postmenopausal women with T2DM and 919 non-diabetic control subjects. Bone mineral density of the posteroanterior spine and of the left hip was measured by use of dual-energy X-ray absorptiometry. Diabetic participants were divided into three groups according to BMI, i.e. low BMI (DML < 18.5 kg/m²), intermediate BMI (DMM 18.5-24.9 kg/m²), and high BMI (DMH >= 25 kg/m²). The BMD values of diabetic subjects between groups exhibited a significant gradient difference, with DML < DMM < DMH. On the fitting curves, where BMD in various skeletal regions varied with age, BMDs of DML were approximately 15% lower than those of DMM, and those of DMM were approximately 10% lower than those of DMH. For prevalence and risks of osteoporosis a gradient difference was observed among diabetic groups, DML > DMM [almost equal to] control > DMH. The osteoporosis risk was higher for the hip than for the lumbar spine, especially in DML. This study indicated that postmenopausal women with T2DM had higher BMD and lower osteoporosis risk in the lumbar spine, and that lower BMI was an indicator of osteoporosis in mainland China.