Context
Type 2 diabetes is associated with higher bone density (BMD) and, paradoxically, with increased fracture risk. It is not known if low BMD, central to fracture prediction in older adults, identifies fracture risk in diabetic patients.
Objective
Determine if femoral neck (FN) BMD T-score and FRAX score are associated with fracture in older diabetic adults.
Design
Three observational studies: Study of Osteoporotic Fractures, Osteoporotic Fractures in Men, and Health, Aging and Body Composition study.
Setting
Older community-dwelling adults in U.S.
Participants
9,449 women; 7,436 men.
Main outcome measure(s)
Self-reported incident fractures, verified by radiology reports.
Results
Of 770 diabetic women, 84 experienced a hip and 262 a non-spine fracture during mean (SD) follow-up of 12.6 (5.3) years. Of 1,199 diabetic men, 32 experienced a hip and 133 a non-spine fracture during mean follow-up of 7.9 (2.5) years. Age-adjusted hazard ratios (HR) for one unit decrease in FN BMD T-score in diabetic women were 1.88 (95% confidence interval [CI], 1.43–2.48) for hip and 1.52 (95% CI, 1.31–1.75) for non-spine fracture. HRs in diabetic men were 5.71 (95% CI, 3.42–9.53) for hip and 2.17 (95% CI, 1.75–2.69) for non-spine fracture. FRAX score was also associated with fracture risk in diabetic participants. However, for a given T-score and age or FRAX score, diabetic participants had a higher fracture risk than those without diabetes. For a similar hip fracture risk, diabetic participants had a higher T-score than non-diabetic participants. The difference in T-score was 0.59 (95% CI, 0.31–0.87) for women and 0.38 (95% CI, 0.09–0.66) for men.
Conclusions
Among older adults with type 2 diabetes, FN BMD T-score and FRAX score were associated with hip and non-spine fracture risk. However, in these patients, compared with participants without diabetes, fracture risk was higher for a given T-score and age or a given FRAX score.