The Association Between Abdominal Obesity And Hip Fracture

Objective:Epidemiological investigations evaluating the association of abdominal obesity with hip fracture risk have yielded conflicting results.The present study investigated the association between abdominal obesity and hip fracture through cross-sectional study and meta-analysis.Methods:In the cross-sectional study,data were collected from 5147 adults aged 50years or older who participated in 2005-2006、2007-2008 and 2009-2010 National Health and Nutrition Examination Survey.The information of hip fracture and anthropometric measurements were collected from this database.Abdominal obesity was defined by waist circumference>102 cm in men and waist circumference>88 cm in women.A body shape index（ABSI）was based on waist circumference and was approximately independent of weight,height and body mass index（BMI）.Logistic regression model was performed to estimate odds ratio（OR）with 95%confidence interval（CI）.In the meta-analysis,three databases including 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:In the cross-sectional study,when comparing the highest tertile with the lowest tertile of ABSI,the OR（95%CI）of hip fracture was 0.88（95%CI:0.42-1.87）after adjusting for the effects of age,gender,marriage,education,smoking,alcohol,health status.When comparing the group of abdominal obesity with the group without abdominal obesity,the OR（95%CI）of hip fracture was 0.32（95%CI:0.17-0.62）after adjusting for the effects of age,gender,marriage,education,smoking,alcohol,health status.After further adjustment for BMI,abdominal obesity was not associated with hip fracture risk.In the meta-analysis,seven studies involving 180600 participants for hip circumference,six studies involving 199828 participants for waist-hip ratio and five studies involving 170796 participants for waist circumference were included.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(P_nonlinearity<0.001)between waist circumference and the risk of hip fracture,and a linear relationship(P_nonlinearity=0.911)suggested that the risk of hip fracture increased about 3.0%（1.03（1.01-1.04））for each 0.1unit increment of waist-hip ratio.Conclusion:The cross-sectional study indicated that abdominal obesity was not associated with hip fracture risk.The meta-analysis suggested that abdominal obesity might be associated with an increased risk of hip fracture.