Diabetes mellitus and incidence and mortality of kidney cancer: A meta-analysis ★

BackgroundDiabetes is associated with increased risk of a spectrum of cancers, but there are few meta-analyses on the association between diabetes and kidney cancer. We performed a meta-analysis of case–control studies and cohort studies to address the incidence and mortality of kidney cancer in diabetes.MethodsStudies were identified by searching PubMed database and manual assessment of the cited references in the retrieved articles. Study-specific relative risks (RRs) and 95% confidence intervals (CIs) were estimated using a random-effect model. Study quality was assessed using the Newcastle–Ottawa scale.ResultsA total of 24 studies were included. We found that diabetes was significantly associated with increased risk of kidney cancer (RR = 1.40, 95% CI = 1.16 to 1.69), and the results were consistent between case–control and cohort studies. A slightly stronger positive relation was observed in women (RR = 1.47, 95% CI = 1.18 to 1.83) than in men (RR = 1.28, 95% CI = 1.10 to 1.48). Additional analyses indicated that the increased risk of kidney cancer was independent of alcohol consumption, body mass index (BMI)/obesity and smoking. However, there was no association between diabetes and mortality of kidney cancer (RR = 1.12, 95% CI = 0.99 to 1.20), without heterogeneity (P = 0.419, I2 = 1.8%).ConclusionsDiabetes mellitus may increase the risk of kidney cancer in both women and men.