Thiazide Diuretics and Fracture Risk: A Systematic Review and Meta-Analysis of Randomized Clinical Trials

Thiazide diuretics are commonly used antihypertensive agents. Until today, whether their use reduces fracture risk remains unclear. Our objective was to conduct a systematic review of thiazide diuretics' effects on fractures and bone mineral density (BMD) in randomized clinical trials (RCT) of adults. MEDLINE, EMBASE, CENTRAL, and the WHO's ICTRP registry were searched from inception to July 31, 2019. Two reviewers assessed studies for eligibility criteria: (i) RCTs; (ii) including adults; (iii) comparing thiazides, alone or in combination; (iv) to placebo or another medication; and (v) reporting fractures or BMD. Conference abstracts and studies comparing thiazides to antiresorptive or anabolic bone therapy were excluded. Bias was assessed using Cochrane Collaboration's Risk of Bias Tool-2. The primary outcome was fracture at any anatomical site. Secondary outcomes were osteoporotic fractures, hip fractures, and BMD at femoral neck, lumbar spine, and/or total hip. Fractures were pooled as risk ratios (RRs) using random-effect models. Prespecified subgroup analyses and post hoc sensitivity analyses were conducted. From 15,712 unique records screened, 32 trials (68,273 patients) met eligibility criteria. Thiazides were associated with decreased fractures at any site (RR = 0.87, 95% confidence interval [CI] 0.77-0.98; I  = 0%) and osteoporotic fractures (RR = 0.80; 95% CI 0.69-0.94; I  = 0%). Results were consistent in most subgroups and sensitivity analyses. Few studies reported hip fractures, and no association was found between thiazides and this outcome (RR = 0.84; 95% CI 0.67-1.04; I  = 0%). Only four studies reported BMD; a meta-analysis was not conducted because BMD reporting was inconsistent. Trials were deemed at low (3 studies, weight = 3%), some concerns (16 studies; 71%), or high (11 studies; 26%) risk of bias for the primary outcome. In conclusion, thiazide diuretics decreases the risk of fractures at any and at osteoporotic sites in a meta-analysis of RCTs. Additional studies are warranted in patients with high fracture risk. © 2022 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.