Aims: To evaluate associations between reproductive health with incident fracture and new osteoporosis diagnosis in women with self-reported type 1 diabetes (T1D) and type 2 diabetes (T2D) compared with controls.
Methods: Longitudinal observational study using data from the Australian Longitudinal Study in Women’s Health (ALSWH). Women aged 45 to 50 years were followed up every three years, for up to 15 years.
Outcomes: Self-reported fracture and osteoporosis diagnosis.
Statistical analyses: Poisson regression analyses for evaluation of incidence rate ratios for fracture and osteoporosis, and multiple linear regression analyses for evaluation of associations between time-to-fracture/osteoporosis between diabetes types.
Results: 107 women with T1D, 1230 with T2D and 10874 controls were included. 1260 incident fractures and 1085 new cases of osteoporosis occurred over 165315 person-years of follow-up. Mean age at baseline was 47 years in all groups. Women in the T1D group had lower mean BMI, (25.5±5.0 vs. 27.5±6.3 vs. 25.8±5.0 kg/m2, p<0.001). Age of natural menopause was significantly lower in T1D (47.4±3.4 vs. 50.2± 4.5 vs. 50.4±3.6, p<0.001). Women with T1D and T2D had a significantly higher prevalence of injurious falls, compared to controls (35.2% vs. 31.7% vs. 26.4%, p<0.001). Neither T1D nor T2D were associated with increased incident fracture risk, although osteoporosis incidence was significantly higher in T1D and T2D, compared with controls (T1D: IRR 1.94, 95%CI 1.10–3.46; T2D: IRR 1.33, 95%CI 1.05–1.70). T1D status was independently associated with a 1.5- and five-year earlier onset of fracture and osteoporosis diagnosis, respectively (fracture: ß -1.68 years, p=0.004; osteoporosis: ß -5.04 years, p<0.001).
Conclusions: Women with T1D have earlier menopause and shorter time to fracture and osteoporosis, compared with both T2D and controls. Diabetes is associated with osteoporosis, and this work confirms the need for consideration of bone health assessment in diabetes, especially around the midlife transition.