Association between first-step analgesic use and cancer in patients with diabetes.

Objectives: This study aimed to determine the effectiveness of analgesics in inhibiting cancer development in patients with diabetes based on a sample cohort supplied by the Korean National Health Insurance Service.

Materials and methods: Regular users of analgesics included those using prescription analgesics ≥ 15 days per month at least 6 times over 2 years after the diagnosis of diabetes mellitus (baseline). The effectiveness of analgesics in patients with diabetes was evaluated using metformin adherence and three models: model 1 was adjusted for age and sex; model 2 was further adjusted for body mass index (BMI), exercise, cholesterol, hypertension, and Charlson comorbidity index (CCI); and model 3 was further adjusted for analgesics.

Results: Based on stringent extraction criteria, the sample had a cancer incidence of 4.6%. The hazard ratios of models 1 and 2 were 0.830 and 0.865, respectively. The adjusted hazard ratio for all variables, including acetaminophen and nonsteroidal anti-inflammatory drugs such as aspirin and ibuprofen, was 0.871 (model 3).

Conclusion: Regular use of analgesics by patients with diabetes decreased their risk of subsequent cancer development in this large national cohort. Compared with participants who did not develop cancer, those with cancer were older and more likely to be male, did not exercise, have more comorbidities (as assessed by CCI), and did not use analgesics regularly.