This Article Full Text Full Text (PDF) All Versions of this Article: 93/7/2786    most recent Author Manuscript (PDF) Submit a related Letter to the Editor Purchase Article View Shopping Cart Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Copyright Permission Google Scholar Articles by Kowalska, I. Articles by Górska, M. PubMed PubMed Citation Articles by Kowalska, I. Articles by Górska, M. Related Collections Diabetes and Insulin Female Endocrinology Metabolism Obesity

Serum Retinol Binding Protein 4 Is Related to Insulin Resistance and Nonoxidative Glucose Metabolism in Lean and Obese Women with Normal Glucose Tolerance

Irina Kowalska, Marek Strczkowski, Agnieszka Adamska, Agnieszka Nikolajuk, Monika Karczewska-Kupczewska, Elbieta Otziomek and Maria Górska

Department of Endocrinology, Diabetology, and Internal Medicine, Medical University of Bialystok, 15-276 Bialystok, Poland

Address all correspondence and requests for reprints to: Irina Kowalska, M.D., Department of Endocrinology, Diabetology, and Internal Medicine, Medical University of Bialystok, M.C. Sklodowskiej 24a, 15-276, Bialystok, Poland. E-mail: irinak{at}poczta.onet.pl.

Context: Retinol-binding protein (RBP) 4 is secreted by adipose tissue and is postulated to be a determinant of insulin sensitivity. The mechanisms of RBP4 insulin desensitizing action remain unclear.

Objective: The aim of the present study was to estimate the relationships between serum RBP4 concentration with insulin sensitivity and oxidative and nonoxidative glucose metabolism in lean and obese women.

Design and Participants: The study group consisted of 67 women with normal glucose tolerance, 27 lean and 40 overweight or obese. Insulin sensitivity was estimated with the euglycemic hyperinsulinemic clamp. Glucose and lipid oxidation was measured with indirect calorimetry in the basal state and during the last 30 min of the clamp. Nonoxidative glucose metabolism was calculated in insulin-stimulated conditions by subtracting glucose oxidation from total glucose metabolism.

Results: There was no difference in serum RBP4 concentration between lean and obese women. Serum RBP4 was inversely related to insulin sensitivity and nonoxidative glucose metabolism in the entire group (r = –0.36, P =0.003 in both cases) and within the subgroups of lean (r = –0.41, P =0.034 and r = –0.41, P =0.031) and obese women (r = –0.41, P =0.009 and r = –0.40, P =0.01, respectively). These relationships were independent of potential confounding factors. RBP4 levels were not associated with oxidative metabolism of glucose or lipid.

Conclusions: Our data indicate that serum RBP4 is related to decreased insulin sensitivity, mostly through its association with nonoxidative glucose metabolism.