Background: Diabetes is associated with reduced tolerance to heat. Theinsulin sensitizer rosiglitazone (RSG), administered for glycemic control, has a secondary effect inincreasing vascular endothelial function. The hypothesis to be tested was if administration of rosiglitazonewould increase heat tolerance in people with diabetes. Material/Methods: Thirty subjects with diabetesand thirty control subjects were examined. A subset of 21 subjects with diabetes had RSG administeredat 4 mg per day for a period of 1 year. At 2 weeks, 4 weeks, 3 months, 6 months, and 1 year post administration,measurements were taken to assess any potential impact of this drug on thermoregulation. Parameters measuredwere sweat rate, skin temperature, body core temperature, and skin blood flow. Results: Results of theseexperiments showed that subjects with diabetes at baseline had 1) sensory impairment, 2) sweat glandimpairment 3) high skin temperatures, 4) and low blood flow reduction during heat exposure, all leadingto higher core temperature compared to controls subjects. After administration of rosiglitazone for 1year significant improvements in thermoregulation were observed. Trends for improvement in thermoregulationwere observed close to that of age matched control subjects. Conclusions: Heat tolerance can be improvedin people with diabetes when taking the insulin sensitizer RSG for Glycemic control, probably due toincreased endothelial cell function.

Keywords: Body Temperature Regulation - drug effects, Diabetes Mellitus, Type 2 - physiopathology, Hot Temperature, Hypoglycemic Agents - pharmacology, Skin Temperature - drug effects, Thiazolidinediones - pharmacology