Uncoupling Protein 3 Content Is Decreased in Skeletal Muscle of Patients With Type 2 Diabetes
- Patrick Schrauwen1,
- Matthijs K.C. Hesselink2,
- Ellen E. Blaak1,
- Lars B. Borghouts2,
- Gert Schaart2,
- Wim H.M. Saris1 and
- Hans A. Keizer2
- 1Department of Human Biology, Maastricht University, Maastricht, the Netherlands
- 2Department of Movement Sciences, Maastricht University, Maastricht, the Netherlands
Abstract
Recently, a role for uncoupling protein-3 (UCP3) in carbohydrate metabolism and in type 2 diabetes has been suggested. Mice overexpressing UCP3 in skeletal muscle showed reduced fasting plasma glucose levels, improved glucose tolerance after an oral glucose load, and reduced fasting plasma insulin levels. However, data regarding the expression of UCP3 in patients with type 2 diabetes is inconsistent, and so far, there have been no reports of UCP3 protein content. Here we compared, for the first time, the protein levels of UCP3 in vastus lateralis muscle in 14 male type 2 diabetic patients (age 49.8 ± 2.1 years; BMI 27.2 ± 1.2 kg/m2; mean ± SE) with 16 male control subjects (age 48.0 ± 1.9 years; BMI 23.4 ± 0.6 kg/m2). We found that UCP3 protein levels were twice as low in patients with type 2 diabetes compared with control subjects (117 ± 16 vs. 58 ± 12 AU; P = 0.007). There was no correlation between UCP3 content and BMI. In conclusion, UCP3 content is lower in type 2 diabetic patients compared with healthy control subjects. These results are consistent with a role for UCP3 in glucose homeostasis and suggest a role for UCP3 in type 2 diabetes.
Footnotes
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Address correspondence and reprint requests to Dr. P. Schrauwen, Nutrition and Toxicology Research Institute Maastricht (NUTRIM), Department of Human Biology, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands. E-mail: p.schrauwen{at}hb.unimaas.nl.
Received for publication 6 April 2001 and accepted in revised form 12 September 2001.
UCP, uncoupling protein.
