The impact of rosiglitazone on heat tolerance in patients with type 2 diabetes

Abstract

Background: Diabetes is associated with reduced tolerance to heat. The insulin sensitizer rosiglitazone (RSG), administered for glycemic control, has a secondary effect in increasing vascular endothelial function. The hypothesis to be tested was if administration of rosiglitazone would increase heat tolerance in people with diabetes.

Material/methods: Thirty subjects with diabetes and thirty control subjects were examined. A subset of 21 subjects with diabetes had RSG administered at 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 measured were sweat rate, skin temperature, body core temperature, and skin blood flow.

Results: Results of these experiments showed that subjects with diabetes at baseline had 1) sensory impairment, 2) sweat gland impairment 3) high skin temperatures, 4) and low blood flow reduction during heat exposure, all leading to higher core temperature compared to controls subjects. After administration of rosiglitazone for 1 year significant improvements in thermoregulation were observed. Trends for improvement in thermoregulation were observed close to that of age matched control subjects.

Conclusions: Heat tolerance can be improved in people with diabetes when taking the insulin sensitizer RSG for Glycemic control, probably due to increased endothelial cell function.