Background and aims: Type 2 diabetes mellitus (DM) has a high prevalence in aging obese postmenopausal women. It is not clear whether or not diabetes produces an increase in bone mineral density or an increase in fracture rates.
Objective: The main objective of this study was to investigate whether type 2 DM produces a higher prevalence of vertebral, hip and non-vertebral fractures in obese postmenopausal Caucasian women. A secondary objective was to study the influence of DM in quantitative ultrasound measurements of the heel (QUS) and bone mineral density (BMD) measured by dual X-ray absorptiometry (DXA), in both lumbar spine (L2-L4) and proximal femur.
Method: This study was a prospective cohort of 111 patients with type 2 DM and 91 control individuals (CTR) over age 65 and obese, recruited from 16 centers in Spain.
Main outcome measures: Lateral dorsal and lumbar X-rays were performed to assess vertebral fractures. Hip and non-vertebral fractures were noted from medical records, written reports or Xray studies. QUS measurements were made of the calcaneus and BMD measurements of the lumbar spine (L2-L4) and proximal femur.
Results: Patients had higher BMD in the lumbar spine (L2-L4) than controls (0.979 g/cm2 vs 0.927 g/cm2, p=0.035), but we found no statistically significant differences in the proximal femur. QUS measurements showed similar values in both groups: BUA (69.3 dB/Mhz vs 66.7 dB/Mhz, p=0.291), SOS (1537 m/sg vs 1532 m/sg, p=0.249) and QUI (87.5 vs 83.7, p=0.153). No statistically significant differences were found in any case. There was no association between vertebral, hip and non-vertebral fractures and DM. The crude odds ratio, without adjusting was 1.045 (CI 95% 0.531 ; 2.059), and the adjusted odds ratio was 0.927 (CI 95% 0.461 ; 1.863).
Conclusions: In obese postmenopausal Caucasian women, type 2 DM produces an increase in BMD of the lumbar spine without changes in BMD of the proximal femur or in QUS measurements of the heel. The prevalence of vertebral, hip and non-vertebral fractures did not increase in type 2 DM.