Change of bone mineral density in postmenopausal women with type 2 diabetes and its related factors

Objective To explore the change in bone mineral density(BMD) and its related factors in postmenopausal women with type 2 diabetes(T2DM).Methods BMD of the lumbar(L 2-4) and proximal femur was measured by dual-energy X-ray absorptiometry in 112 postmenopausal T2DM patients and 74 non-diabetic controls. Serum Ca,P and alkaline phosphatase(ALP) were measured in two groups.HbA1c,cholesterin and triglyceride were also measured in the diabetic patients.Results Postmenopausal T2DM patients had significantly higher BMD at L 2,L 3,L 4,femoral neck,ward triangle and greater trochanter(GT) as compared with non-diabetic controls(P 0.01).Diabetes mellitus(DM) A group(DM course no more than 5 years) and DM-B group(DM course more than 5 years) had higher BMD than non-diabetic controls at the above areas.Over all areas studied except L 2,DM-A group had higher BMD than DM-B group.By stepwise multiple regression analysis,BMD at femoral neck,ward triangle and GT was negatively correlated with age(P 0.01),BMD at L 2,L 3,and L 2-L 4 was negatively correlated with years since menopause(YSM) and HbA1c(P 0.05),BMD at L 2 and GT was positively correlated with body mass index(BMI)(P 0.05).There were no significant difference in Ca,P and ALP values in serum between the diabetes and controls.Conclusion BMD in postmenopausal T2DM patients had significantly higher than non-diabetic controls.Age,HbA1c and YSM appeared to be the risk factors for decreased BMD in the diabetic patients.BMI may be protected against bone loss.