The Insulin Sparing Effect of Telmisartan in a Case of Type 2 Diabetes Mellitus Associated with Schizophrenia under Treatment of Risperidone

Abstract

A male patient was diagnosed with diabetes mellitus at age 37 and insulin treatment was introduced at age 49. About 2 years after the introduction of insulin, the antihypertensive agent was switched from candesartan (4 mg/day) to telmisartan (20 mg/day). The alteration improved his glycemic control dramatically, with the HbA1c levels decreasing from 8.3% to 6.0% in 6 months. Gradual marked reduction in insulin requirement was observed as it was reduced from 62 U/day to 46 U/day in 6 months and to 18 U/day in 15 months. Also his body weight was reduced from 81 kg to 65 kg in 15 months without remarkable life-style modification. Throughout the whole clinical course mentioned above, he was under treatment for schizophrenia with drugs including risperidone which possibly affects glucose metabolism. The medication for schizophrenia was not changed during this period. We present here the marked glycemia improvement effect and insulin sparing effect of telmisartan in a case of type 2 diabetes mellitus.