Objective — To characterize the demographic and clinical profiles of older persons with diabetes treated with a thiazolidinedione (TZD) in comparison to other groups of patients, including all patients with diabetes and those taking other oral hypoglycemic agents (OHAs).
Research Design and Methods — We studied Ontario residents aged 66 and older and alive on 31 March 2008. Five groups were created based on diabetes status and history of treatment with OHAs, including patients prescribed rosiglitazone, patients prescribed pioglitazone, and a sample of three other groups: patients prescribed any other OHA in the preceding year, all patients with diabetes, and elderly Ontarians regardless of diabetes status. We excluded patients receiving insulin or multiple TZDs from the three OHA groups. Study groups were compared based on demographic information, measures of comorbidity, history of cardiovascular diseases, and concomitant use of drugs for cardiovascular disease.
Results — People treated with pioglitazone (n = 16 206) were highly similar to those treated with rosiglitazone (n = 16 066). Individuals treated with either TZD tended to be younger, less likely to reside in a long-term care facility, and had similar cardiovascular profiles to samples of patients with diabetes (n = 50 000) and those taking other OHAs (n = 50 000).
Conclusions — Older patients started on TZDs have cardiovascular risk profiles comparable to other individuals with diabetes, including those taking other OHAs, suggesting that observational studies of TZD safety are not likely confounded by selection bias.