Type 2 diabetes mellitus does not increase the risk of lung cancer among never-smokers: a nationwide cohort study

Abstract

Previous studies have reported higher incidences of lung cancer among smokers diagnosed with diabetes than those without. Accordingly, this study investigated whether type 2 diabetes mellitus (T2DM) diagnosis alone can be associated with increased lung cancer incidences among never-smokers in the Korean population. Newly diagnosed never-smoking T2DM patients were identified from the nationwide longitudinal cohort of health examination data of South Korea (2002-2013). Cox proportional hazards regression model was employed to estimate the hazard ratios (HRs) and 95% confidence interval (CI) of lung cancer in the T2DM patient and abnormal fasting blood sugar (FBS) groups. T2DM (HR =0.91, 95% CI: 0.71 to 1.17) and abnormal FBS level are no significant association with lung cancer incidence based on the given HR. T2DM does not increase the risk of lung cancer among never-smokers. A large cohort study affirms minimal impact of T2DM on lung cancer development in the never-smoking Korean population.

Keywords: Lung cancer; longitudinal study; type 2 diabetes mellitus cohort analysis (T2DM cohort analysis).

Figure 1

Flow chart of inclusion in the study population. ^a, missing values for sociodemographic characteristics (age, gender, household income), behavioral factors (alcohol consumption, tobacco smoking, physical activity), and medical conditions (CCI score, body mass index, type 2 diabetes, systolic blood pressure, FBS, total serum cholesterol). T2DM, type 2 diabetes mellitus; FBS, fasting blood sugar; CCI, Charlson Comorbidity Index.