Diabetes in postmenopause: different influence on bone mass according to age and disease duration.

Objective: Studies addressing the influence of diabetes mellitus on bone metabolism have yielded conflicting results. The aim of the present study is to investigate the bone mineral density (BMD) status of postmenopausal diabetic women with different ages or diabetes duration.

Methods: Two hundred postmenopausal women with type 2 diabetes (DM) and 800 postmenopausal healthy women (PMP), serving as control subjects, were studied. Subjects were divided into either 6 groups according to 5 year age segments, or 6 groups according to 5 year segments of diabetes duration. BMD was measured at the femoral neck and at the trochanter major with dual energy X-ray absorptiometry.

Results: Diabetic women studied as a whole, exhibited significantly higher BMD values compared to healthy postmenopausal women at both femoral neck and trochanter. Diabetic women of 48-53, 53-58, 58-63 and 63-68 age groups had significantly higher BMD values than the respective control groups, whereas BMD values of DM 73-78 were significantly lower compared to the PMP 73-78 group at both anatomic sites. When the same diabetic women were divided according to diabetes duration (DUR), groups DUR 6-10 and DUR 11-15 exhibited significantly higher BMD values at both anatomic sites compared to control groups. In contrast, BMD values of group DUR 21-25 were significantly lower only at the femoral neck.

Conclusions: Type 2 diabetes mellitus' influence on bone metabolism seems to depend on the patient's disease duration and age. The initial positive effect on bone mass appears to be ameliorated as age or disease duration advance. Studies concerning type 2 diabetes and bone mass should take these parameters into account.