Abdominal obesity and risk of hip fracture: a meta-analysis of prospective studies

Abstract

Summary: We conducted a meta-analysis to qualitatively summarize the evidence of the association between abdominal obesity and hip fracture risk. The results indicated that abdominal obesity as measured by waist circumference and waist-hip ratio might be associated with an increased risk of hip fracture. Introduction: Epidemiological investigations evaluating the association of abdominal obesity with hip fracture risk have yielded conflicting results. Therefore, a meta-analysis was conducted to qualitatively summarize the evidence of the associations between waist circumference, waist-hip ratio, and hip circumference and the risk of hip fracture, respectively. Methods: PubMed, Embase, and Web of Science were searched for relevant articles published up to March 2017. Pooled relative risks (RRs) with 95% confidence intervals (CIs) were calculated with a random-effects model. Dose-response relationship was assessed by restricted cubic spline. Results: Seven studies involving 180,600 participants for hip circumference, six studies involving 199,828 participants for waist-hip ratio, and five studies involving 170,796 participants for waist circumference were finally included in this meta-analysis. The combined RRs with 95% CIs of hip fracture for the highest versus lowest category of waist circumference, waist-hip ratio, and hip circumference were 1.58 (95% CI 1.20–2.08), 1.32 (95% CI 1.15–1.52), and 0.87 (95% CI 0.74–1.02), respectively. For dose-response analysis, a nonlinear relationship was found (Pnonlinearity < 0.001) between waist circumference and the risk of hip fracture, and a linear relationship (Pnonlinearity = 0.911) suggested that the risk of hip fracture increased about 3.0% (1.03 (1.01–1.04)) for each 0.1 unit increment of waist-hip ratio. Conclusions: This meta-analysis suggested that abdominal obesity as measured by waist circumference and waist-hip ratio might be associated with an increased risk of hip fracture. From a public health perspective, indicators of abdominal obesity may be usable predictors of hip fracture risk.