HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Online-Only Appendix All Versions of this Article: db07-0887v1 57/1/56    most recent Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted 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 Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Pereira, S. Articles by Gougeon, R. Search for Related Content PubMed PubMed Citation Articles by Pereira, S. Articles by Gougeon, R. Social Bookmarking                What's this?

Insulin Resistance of Protein Metabolism in Type 2 Diabetes

McGill Nutrition and Food Science Centre, McGill University Health Centre/Royal Victoria Hospital, Montreal, Quebec, Canada

Address correspondence and reprint requests to Réjeanne Gougeon, McGill Nutrition and Food Science Centre, MUHC/Royal Victoria Hospital, 687 Pine Ave. West, H6.61, Montreal, QC H3A 1A1, Canada. E-mail: rejeanne.gougeon{at}muhc.mcgill.ca

Key Words: -KIC, -ketoisocaproic acid • BCAA, branched-chain amino acid • FFA, free fatty acid • FFM, fat-free mass • HOMA-IR, homeostasis model assessment of insulin resistance • REE, resting energy expenditure

OBJECTIVE—We previously demonstrated that 1) obesity impairs and 2) sex influences insulin sensitivity of protein metabolism, while 3) poor glycemic control in type 2 diabetes accelerates protein turnover in daily fed-fasted states. We hypothesized that type 2 diabetes alters the insulin sensitivity of protein metabolism and that sex modulates it.

RESEARCH DESIGN AND METHODS—Hyperinsulinemic (570 pmol/l), euglycemic (5.5 mmol/l), and isoaminoacidemic (kept at postabsorptive concentrations) clamps were performed in 17 hyperglycemic type 2 diabetic subjects and 23 subjects without diabetes matched for age and body composition, after 7 days on a inpatient, protein-controlled, isoenergetic diet. Glucose and leucine kinetics were determined using tracers.

RESULTS—In type 2 diabetes, postabsorptive (baseline) glycemia was 8–9 mmol/l, glucose production (R_a) and disposal (R_d) were elevated, and once clamped, endogenous glucose R_a remained greater and R_d was less (P < 0.05) than in control subjects. Baseline leucine kinetics did not differ despite higher insulin levels. The latter was an independent predictor of leucine flux within each sex. With clamp, total flux increased less (P = 0.016) in type 2 diabetic men, although protein breakdown decreased equally (20%) in male groups but less in female groups. Whereas protein synthesis increased in male control subjects and in both female groups, it did not in male subjects with type 2 diabetes. In men, homeostasis model assessment of insulin resistance predicted 44%, and, in women, waist-to-hip ratio predicted 40% of the change in synthesis.

CONCLUSIONS—During our clamp, men with type 2 diabetes have greater insulin resistance of protein metabolism than that conferred by excess adiposity itself, whereas women do not. These results may have implications for dietary protein requirements.

CiteULike    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				N. Moller and K. S. Nair Diabetes and Protein Metabolism Diabetes, January 1, 2008; 57(1): 3 - 4. [Full Text] [PDF]