Treatment intensity-dependent association between the number of oral hypoglycemic agents and insulin use and lung cancer risk in patients with type 2 diabetes.

BACKGROUND

Although diabetes mellitus is a risk factor for lung cancer, the association between oral hypoglycemic agents (OHAs) and insulin use and lung cancer risk remains unclear. We investigated the association between the number of OHAs and insulin and lung cancer risk.

METHODS

Individuals who participated in the 2015-2016 national health examination were screened using the Korean National Health Information Database. A total of 2,338,170 individuals with type 2 diabetes mellitus were followed up until December 2022; among them, 25,198 individuals with newly developed lung cancer were identified. Data on prescription of OHAs and insulin within 1 year after health examination were collected. Multivariable Cox proportional hazards models were used to estimate adjusted hazard ratios (aHRs) for lung cancer risk factors.

RESULTS

The mean participant age was 59.2±12.0 years, with men accounting for 60.5%. Compared with individuals who were not prescribed OHAs and insulin, lung cancer risk increased with the number of OHAs in a treatment-intensity-dependent association [≥3 OHAs, aHR: 1.21, 95% confidence interval (CI): 1.15-1.28]. Insulin users exhibited the highest risk (incidence rate of 2.51 per 1,000 person-years, aHR: 1.35, 95% CI: 1.27-1.43). Stratified analyses revealed that an increased lung cancer risk was more prominent among individuals aged <65 years, males, current smokers, and heavy drinkers.

CONCLUSIONS

A higher number of OHAs was associated with an increased risk of lung cancer in a treatment-intensity-dependent association, and insulin users exhibited the greatest risk in type 2 diabetes. Lung cancer risk was augmented if individuals were aged <65 years, males, current smokers, or heavy drinkers.