Prevalence of osteoporosis among postmenopausal females with diabetes mellitus

OBJECTIVE: To assess the prevalence of osteopenia and osteoporosis among Saudi postmenopausal women with non-insulin dependent type 2 diabetes mellitus (T2DM).

METHODS: The study was carried out at King Khalid University Hospital, Riyadh, Kingdom of Saudi Arabia from February 2000 to September 2002. Bone mineral density (BMD) of the lumbar spine and femoral neck using dual x-ray absorptiometry (DXA; Lunar Wisconsin), were performed in 104 postmenopausal Saudi women with T2DM, and 101 postmenopausal non-diabetic women (control). Bone mineral density was measured in gm/cm2 and both T-score and Z-score were measured but only T-score was used for analysis based on World Health Organization criteria. Bone profile, 25(OH) Vitamin D, 1,25(OH)2 Vitamin D, parathyroid hormone and urine deoxypyridinoline (DPD) were measured in most patients and controls. Body fat measurement around the biceps muscles using Futrex (body composition analyzer) were performed in patients and controls. Years postmenopausal, duration of diabetes mellitus, parity, exercise, sun exposure and milk consumption were also recorded.

RESULTS: In the diabetic group, the mean spine BMD was 0.928 gm/cm2 (T-score = -2.28 SD) and for femoral neck the mean BMD was 0.817 gm/cm2 (T-score = -1.21 SD). In control group, the mean spine BMD was 1.036 gm/cm2 (T-score = -1.2) and mean femoral neck BMD was 0.914 gm/cm2 (T-score = -0.608). In the diabetic group, there was 16 (16.64%) patients with normal BMD of the spine, 42 patients (43.68%) with osteopenia (mean T-score = -1.8 SD) and 45 (46.8%) with osteoporosis (mean T-score = -3.3 SD).

CONCLUSION: Osteoporosis is more common among Type 2 postmenopausal females in this ethnic group. Since both groups are postmenopausal, having equal percentage of Vitamin D deficiency, multi-parity, non exposure to sun, lack of exercise and negligible milk intake, one can conclude that the low BMD can be attributed to DM in the absence of other causes of osteoporosis.