Associations of diabetes status, duration, and onset age with the risk of lung cancer: Results from the China Kadoorie Biobank study

This study examined the associations of diabetes status, duration, and age at onset with lung cancer risk in the China Kadoorie Biobank. We prospectively assessed the association between diabetes status and lung cancer risk in 510,148 cancer-free participants, with analyses of duration and age at onset among 29,962 participants with diabetes at baseline. Multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox regression models, and effect modification was assessed across stratified subgroups using likelihood ratio tests. During a median 9.17-year follow-up, 5007 lung cancer cases occurred. Compared with participants without diabetes, those with diabetes had a higher lung cancer risk (HR = 1.15, 95% CI: 1.01-1.32). Diabetic patients with onset <40 years showed a 2.81-fold higher lung cancer risk (95% CI: 1.31-6.02) compared to ≥60-year onset groups. Longer duration (≥15 vs. <1 year) was associated with increased risk (HR = 2.06, 95% CI: 1.33-3.19). The association with diabetes status was stronger among individuals with below-median physical activity, while the association with diabetes duration was more pronounced in overweight participants. Overall, these findings indicate that diabetes, especially with earlier onset and longer duration, significantly increases lung cancer risk, highlighting the need for screening and targeted management in high-risk populations.