Article Text
Abstract
Introduction Increased body mass index (BMI) is a risk factor for kidney cancer. However, previous reviews on this topic included only studies that reported on mid-life BMI. We carried out an updated and more comprehensive review to describe the association between lifecourse measures of body composition and kidney cancer risk.
Methods We searched MEDLINE, EMBASE, ISI and four other databases in July 2010. We assessed identified studies against pre-specified criteria, and extracted data using a standard form. We used fixed and random-effects meta-analyses to derive a pooled OR and CIs for the association between kidney cancer risk and measures of body composition.
Results We identified 17898 hits; 741 papers were retrieved and assessed. Seventy-three papers met inclusion criteria and will be included in updated meta-analyses. Based on results from our previous search (April 2007, 52 studies), higher BMI was associated with kidney cancer (OR 1.39; 95% CI 1.30 to 1.47 per 5 kg/m2 increase), with a linear dose-response observed for most studies. Measures of body composition, including waist circumference, waist-to-hip ratio and weight-cycling showed a similar trend, although derived from a smaller number of studies. We are currently updating our meta-analyses with recent studies, focusing on measurements of body composition other than BMI.
Conclusion The linear dose-response, across a range of BMI, suggests that even mildly overweight individuals may decrease their risk of kidney cancer via small reductions in BMI. Updating evidence on other measurements of body composition will further elucidate the relationship between body size and kidney cancer.