Long-term studies demonstrating the effect of pioglitazone use on primary prevention of ischemic cerebrovascular disease in older people with type 2 diabetes mellitus are lacking. This study investigated the relationship between pioglitazone use and first attack of ischemic cerebrovascular disease in Taiwan.

We conducted a case-control study using the database of the Taiwan National Health Insurance Program. There were 2359 type 2 diabetic subjects aged ≥65 years with newly diagnosed ischemic cerebrovascular disease from 2005 to 2011 as the case group and 4592 sex- and age-matched, randomly selected type 2 diabetic subjects aged ≥65 years without ischemic cerebrovascular disease as the control group. The odds ratio (OR) with 95% confidence interval (CI) of ischemic cerebrovascular disease associated with pioglitazone use was measured by the multivariable unconditional logistic regression model.

After adjustment for confounding factors, the multivariable logistic regression analysis disclosed that the adjusted ORs of first attack of ischemic cerebrovascular disease associated with cumulative duration of using pioglitazone were 3.34 for <1 year (95% CI 2.59–4.31), 2.53 for 1 to 2 years (95% CI 1.56–4.10), 2.20 for 2 to 3 years (95% CI 1.05–4.64), and 1.09 for ≥3 years (95% CI 0.55–2.15), respectively.

Our findings suggest that pioglitazone use does not have a protective effect on primary prevention for ischemic cerebrovascular disease among older people with type 2 diabetes mellitus during the first 3 years of use. Whether using pioglitazone for >3 years would have primary prevention for ischemic cerebrovascular disease needs a long-term research to prove.