Obesity Comorbidity Hip circumference, height and risk of type 2 diabetes: systematic review and meta-analysis M. Janghorbani, F. Momeni and M. Dehghani Department of Epidemiology and Biostatistics, Isfahan University of Medical Sciences, Isfahan, Iran Received 7 June 2012; revised 7 August 2012; accepted 7 August 2012 Address for correspondence: Professor M Janghorbani, Department of Epidemiology and Biostatistics, School of Public Health, Isfahan University of Medical Sciences, Isfahan 81745, Iran. E-mail: janghorbani@hlth.mui.ac.ir Summary Although several epidemiological studies have investigated the relationship between type 2 diabetes mellitus (T2DM) and hip circumference or height, the results are inconsistent. The present systematic review and meta-analysis of pub- lished observational studies was conducted to assess the effects of hip circumfer- ence and height on diabetes risk. Online databases were searched through January 2012, and the reference lists of pertinent articles reporting observational studies in humans were examined. Pooled relative risks (RR) and 95% confidence intervals (CI) were calculated with a random-effects model. Eighteen studies (nine cross- sectional and nine cohort) were included, with 250,497 participants and 7,765 cases of T2DM. Hip circumference was inversely associated with an increased risk of T2DM in men (summary RR [95% CI] 0.60 [0.45, 0.80]) and women (0.54 [0.42, 0.70]). These results were consistent between cross-sectional and cohort studies. An inverse association between height and T2DM was observed in women only (summary RR [95% CI] 0.83 [0.73, 0.95]). Our meta-analysis strongly supports an inverse relationship between hip circumference and risk of T2DM in men and women. The inverse association between height and risk was significant only in women. Keywords: Diabetes mellitus, height, hip circumference, meta-analysis. obesity reviews (2012) 13, 1172–1181 Introduction Type 2 diabetes mellitus (T2DM) is a major cause of mor- bidity and premature mortality worldwide, and its preva- lence is increasing in both developed and developing countries. It is well established that obesity is associated with increased risk of T2DM (1,2). Epidemiological studies have demonstrated that different anthropometric measures of obesity such as body mass index (BMI), waist circum- ference (WC), waist-hip ratio and waist-height ratio (WHtR) are strong and consistent predictors of type 2 diabetes (1,2). The relationship between increased BMI, waist-hip ratio or WHtR and T2DM risk may be due to a direct effect of obesity or to inverse effects of hip circum- ference (HC) or height. Although several epidemiological studies have investi- gated the association between HC or height and risk of T2DM, the role of HC and height as risk factors for T2DM remains uncertain, and reports about the risk of T2DM and HC or height have produced conflicting results (3–18). HC appears to be inversely associated with T2DM in most (3,6–10,16–18) but not all studies (5,8,14), and some studies found an association only in women (4). There have also been conflicting reports about the possible association obesity reviews doi: 10.1111/j.1467-789X.2012.01030.x 1172 © 2012 The Authors obesity reviews © 2012 International Association for the Study of Obesity 13, 1172–1181, December 2012