Association Between Glycemic Status and the Risk of Kidney Cancer in Men and Women: A Nationwide Cohort Study.

OBJECTIVE:Kidney cancer predominantly affects men, suggesting a biological protection against kidney cancer in women. We investigated the dose-response association between glycemic status and kidney cancer risk in men and women. RESEARCH DESIGN AND METHODS:In this nationwide cohort study, 9,492,331 adults without cancer who underwent national health screening in 2009 were followed up until 31 December 2018. We estimated kidney cancer risk using multivariable Cox proportional hazard regression models after adjusting for potential confounders. RESULTS:During the 78.1 million person-years of follow-up, incident kidney cancer occurred in 8,834 men and 3,547 women. The male-to-female ratio of the incidence rate was 2.1:1 in never-smokers with normoglycemia (17.8 vs. 8.5/100,000 person-years). Among never-smokers, men with diabetes, but not prediabetes, had an increased risk of kidney cancer (adjusted hazard ratio [aHR] 1.25 [95% CI 1.12-1.38] and 1.06 [0.97-1.15], respectively). Among never-smokers, women with both diabetes and prediabetes had an increased risk (aHR 1.34 [95% CI 1.21-1.49] and 1.19 [1.10-1.29], respectively) (Ptrend <0.01). Among smokers, men and women with diabetes had 49% and 85% increased kidney cancer risk (aHR 1.49 [95% CI 1.37-1.61] and 1.85 [1.26-2.73], respectively). CONCLUSIONS:Glycemic status and kidney cancer risk exhibited a dose-response association in women. Diabetes, but not prediabetes, was associated with an increased risk in men. Although women have a lower risk of kidney cancer than men, women with even prediabetes have an increased risk. These findings should not be overlooked when monitoring for kidney complications.