Context: Type 2 diabetes is associated with a higher risk for major osteoporotic fracture (MOF) and
hip fracture than predicted by the World Health Organization fracture risk assessment (FRAX) tool.
Objective: The objective of the study was to examine the impact of diabetes duration on fracture
risk.
Methods: Using a clinical dual-energy x-ray absorptiometry registry linked with the Manitoba
administrative databases, we identified all women age 40 years or older with 10 or more years of
prior health care coverage undergoing hip dual-energy x-ray absorptiometry measurements
(1996 –2013). Incident MOF and incident hip fractures were each studied over 7 years. Cox proportional
hazards models were adjusted for FRAX (FRAX adjusted) and then FRAX plus comorbidity,
falls, osteoporosis therapy, or insulin (fully adjusted). FRAX calibration was assessed comparing
observed vs predicted probabilities.
Results: There were 49 098 women without and 8840 women with diabetes (31.4%10 y duration;
20.1% 5–10 y; 23.7%5 y; 24.8% new onset). In FRAX-adjusted analyses, only duration longer than
10 years was associated with a higher risk for MOF (hazard ratio [HR] 1.47, 95% confidence interval
[CI] 1.30 –1.66), and this was similar in the fully adjusted models (HR 1.34, 95% CI 1.17–1.54). In
contrast, a higher risk for hip fracture was seen for all durations in a dose-dependent fashion (eg,
FRAX adjusted HR 2.10, 95% CI 1.71–2.59 for duration 10 y vs HR 1.32, 95% CI 1.03–1.69 for new
onset). FRAX significantly underestimated the MOF risk (calibration ratio 1.24, 95% CI 1.08 –1.39)
and hip fracture risk (1.93, 95% CI 1.50 –2.35) in those with a diabetes duration longer than 10 years.
Conclusion: Diabetes is a FRAX-independent risk factor for MOF only in women with a long duration
of diabetes, but diabetes increases hip fracture risk, regardless of duration. Those with
diabetes longer than 10 years are at particularly high risk of fracture, and this elevated risk is
currently underestimated by FRAX.
CORE (COnnecting REpositories)
CORE (COnnecting REpositories)