The risk of cancer among insulin glargine users in Lithuania: A retrospective population-based study.

Objectives: The aim of this study was to determine the association between insulin glargine usage and the potential increase in cancer risk among the Lithuanian population diagnosed with type 2 diabetes mellitus (T2DM).

Methods: A retrospective cohort study was conducted. The cohort of insulin users was established by identifying all male and female patients diagnosed with T2DM, as recorded in the National Health Insurance Fund database between 1 January 2000 and 31 December 2012. The risk of cancer among insulin glargine users was compared with the risk in non-glargine insulin users. Cox proportional hazard models were used to estimate hazard ratios (HR) and their 95% confidence intervals (CI).

Results: The overall cancer risk for all sites combined showed no significant difference (HR 0.84, 95% CI 0.67-1.05). Although a general decrease in the risk of cancers was observed at most sites for glargine users, the use of insulin glargine was associated with a non-significant increase in the risk of mouth and pharynx, stomach, non-melanoma skin, breast, cervical, ovarian, and central nervous system cancers. There was a tendency for a lower risk of colon, rectum, rectosigmoid, and anus cancer among glargine users (HR 0.45, 95% CI 0.18-1.12, p = 0.09).

Conclusions: Our research contributes to the growing body of evidence showing that insulin glargine is not associated with an increased risk of all cancers or specific types of cancer.