Prevalence and Predictors of Osteopenia and Osteoporosis in Postmenopausal Chinese Women with Type 2 Diabetes

Aims: To determine the prevalence and biochemical/hormonal determinants of osteopenia/osteoporosis in postmenopausal Chinese women with type 2 diabetes.

Methods: This cross-sectional study was carried out in 890 postmenopausal women with type 2 diabetes and 689 age-matched non-diabetic women. Of the total subjects included in both groups were classified as obese (BMI ≥ 25 kg/m²) and non-obese (BMI< 25 kg/m²). Bone mineral density (BMD) at the sites (lumbar spine, femoral neck, and hip), obtained by dual X-ray absorptiometry and some other relevant clinical and laboratory indices of bone mineral metabolism were investigated. The prevalence of osteopenia and that of osteoporosis were evaluated.

Results: BMDs, T- and Z-scores at the total hip, femoral neck and ward's triangle were significantly lower in non-obese diabetic women than those in BMI-matched control subjects (P < 0.038). Obese diabetic patients and control subjects had similar BMDs and T- and Z-scores at various skeletal regions. Osteopenia/osteoporosis was more common at the hip and femoral neck in non-obese diabetic women than in obese diabetic women and control subjects (P = 0.026). On multiple linear regression analysis, which was adjusted for the sex hormone concentration, BMI, fasting insulin level, and serum osteocalcin were positively associated with BMDs at the hip and lumbar spine. Age, mean HbA₁(c) levels, and NTx/Cr showed negative correlation (P < 0.0284) with BMD at the lumbar spine and femoral neck.

Conclusions: Postmenopausal non-obese women with type 2 diabetes have lower BMD levels and higher osteopenia/osteoporosis rate than BMI-matched control subjects. Impaired bone formation may occur in Chinese postmenopausal women with type 2 diabetes.