Risk factors for fractures and falls in older women with type 2 diabetes mellitus

Type 2 diabetes mellitus (DM) is associated with an increased risk of hip fractures despite patients with this condition having normal to high bone mineral density (BMD). Therefore, nonskeletal risk factors may be important in the etiology of fractures in these patients. The aim of this cross-sectional retrospective study was to determine risk factors for falling and fracture in older women with type 2 DM. We randomly recruited 150 women from a community-based diabetes register. They underwent detailed clinical assessment, and BMD was measured by dual-energy X-ray absorptiometry (DXA) and heel quantitative ultrasound (QUS). Mean age was 74 years, mean duration of DM 11 years, mean body mass index 30 kg/m2, and mean HbA1c 7.6%. Mean BMD Z scores were significantly higher than the manufacturer's reference range for all skeletal sites. Previously, 53/150 (35%) of the women had reported a low trauma fracture. The fracture group did not differ significantly from the nonfracture group by age, diabetes-related risk factors or DXA BMD Z scores. However, QUS variables were lower in the fracture group (P = 0.04). A history of one or more falls in the previous 12 months was reported by 61/89 (41%) women. Fallers had a higher vibration perception threshold vs. nonfallers (mean 21.1 vs. 17.6 volts, respectively; P = 0.05). There were no other differences in diabetes or fall-related risk factors. These data suggest that reduced vibration perception (a measure of peripheral neuropathy) is an important risk factor for falling and that QUS, as opposed to DXA, may be a more useful method for fracture risk prediction in older women with type 2 DM. These findings need to be confirmed prospectively.