Angiotensin Receptor Blockade and Risk of Cancer in Type 2 Diabetes Mellitus: A Nationwide Case-Control Study

Abstract

Purpose The objective of this case-control study was to evaluate the risk of malignancy in diabetic patients who received angiotensin receptor blockers (ARBs). Patients and Methods A total of 21,750 new diabetic patients who started antihypertensive treatment were identified from the Taiwan National Health Insurance claims database during the period from July 1, 2000, to December 31, 2000. As of December 31, 2007, patients with incident cancer were included as cases and up to four age- and sex-matched controls were selected by risk-set sampling. Logistic regression models were applied to estimate the odds ratios (ORs) and 95% CIs between ARB use and cancer incidence, adjusted for other types of antihypertensive drugs, insulin, oral hypoglycemic agents, statins, and underlying diseases. Results Among the 1,281 patients with incident cancer and 5,104 controls, 333 (26.0%) and 1,341 (26.3%), respectively, received ARBs (OR, 0.98; 95% CI, 0.85 to 1.14). There was no statistically significant association between the effect of ARBs as a class and cancer incidence after adjustment for covariates (OR, 0.94; 95% CI, 0.80 to 1.10). Among the individual ARBs, losartan decreased the risk (OR, 0.78; 95% CI, 0.63 to 0.97) and candesartan (OR, 1.79; 95% CI, 1.05 to 3.06) and telmisartan (OR, 1.54; 95% CI, 0.97 to 2.43) possibly increased the risk of occurrence of malignancy. Conclusion The results did not show an effect of ARBs as a class on increasing cancer incidence in patients with diabetes. However, there was a negative association of losartan but a positive one of candesartan and telmisartan with the overall occurrence of cancer. The underlying mechanism certainly requires further investigation.