Long-term thiazide use and risk of low-energy fractures among persons with Alzheimer’s disease—nested case-control study

SUMMARY: We investigated the association between thiazide use and the risk of low-energy fractures among community dwellers with Alzheimer’s disease. Longer use was associated with a decreased risk of low-energy fractures. This study extends the previous knowledge of reduced fracture risk of thiazides to persons with Alzheimer’s disease. INTRODUCTION: To investigate the association between thiazide use and the risk of low-energy fractures (LEF), and hip fracture among community dwellers with Alzheimer’s disease (AD). No prior study has evaluated the effect of thiazides on LEF risk of AD patients. METHODS: LEF cases were identified from the MEDALZ study, including all community-dwelling persons diagnosed with AD in Finland 2005–2011. During the follow-up from AD diagnoses until the end of 2015, cases with LEF (N = 10,416) and hip fracture (N = 5578) were identified. LEF cases were matched with up to three controls without LEF, according to time since AD diagnosis, age and gender. Thiazide use identified from the Prescription register data was modeled with PRE2DUP method. Current use was defined in 0–30 days’ time window before the fracture/matching date, and duration of current use was assessed. The association between thiazide exposure and LEFs was assessed with conditional logistic regression. RESULTS: Current thiazide use was observed in 10.5% of LEF cases and 12.5% of controls. Current thiazide use was associated with a decreased risk of LEF (adjusted OR [aOR] 0.83, 95% CI 0.77–0.88). In terms of the duration of use, no association was observed with short-term use (< 1 year or 1–3 years), while longer use (> 3 years) was associated with a reduced risk of LEF (aOR 0.77, 95% CI 0.71–0.83) and hip fracture (aOR 0.68, 95% CI 0.60–0.78). CONCLUSIONS: Our study extends the previous knowledge of reduced fracture risk of thiazides to persons with AD, a population with significantly increased background risk of fractures. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s00198-019-04957-0) contains supplementary material, which is available to authorized users.