Journal of Nutrition & Food Sciences
Open Access
ISSN: 2155-9600
+32 25889658
ISSN: 2155-9600
+32 25889658
Ayla Coussa, Errol B Marliss, Stephanie Chevalier, Jose A Morais, Marie Lamarche, Michael Tsoukas and Rejeanne Gougeon
McGill University, Canada
Posters & Accepted Abstracts: J Nutr Food Sci
Background: Visceral adiposity is an important factor in insulin resistance as it contributes to blunted protein anabolism in diabetes, also known as sarcopenic obesity. Insulin sensitivity of protein metabolism (rate of anabolism and catabolism) in obese type-2 diabetics does not improve with glycemic control with medication or when enhancing dietary protein, although rates of protein turnover decrease. Maintaining protein intakes at a fixed percentage of energy in weight-loss diets exacerbate insulin sensitivity of protein metabolism. Purpose: To investigate changes in insulin sensitivity of glucose and protein metabolism in obese diabetic adults over 5 weeks of energy restriction with maintained abundant protein intake. Methodology: 6 adult diabetics were enrolled. The energy-restricted diet provided 60% of energy requirements with 26% as protein (1.8-1.9 g/kg lean body mass/day). Isotopic tracers were used to quantify whole-body glucose (3-3H-glucose) and protein (13C-leucine) metabolism both pre and post weight loss, post absorptive and during a hyperinsulinemic (~500 pM), isoglycemic (149.4�±9.0 Pre vs. 104.4�±5.4 mg/dl post), isoaminoacidemic clamp. Changes in body composition were measured by dual-energy X-ray absorptiometry. Results: At 5 weeks of energy restriction, weight-loss was mainly attributed to total and visceral fat losses, while lean mass was preserved. Fasting plasma glucose was near normal and serum insulin, C-peptide and HOMA-IR decreased significantly as well as other cardiovascular risk factors. Post absorptive protein turnover decreased by 12% and rates of oxidation by 32% resulting in sparing of body protein, rates of glucose turnover decreased by 29% and glucose metabolic clearance rate improved by 24%. During clamp, protein turnover rates were lower and catabolism was suppressed by 12%. Conclusion: Maintaining abundant protein intake preserves lean body mass in conditions of energy deficit and insulin resistance. Our data is critical to guide future clinical trials and serves as a gauge for future clinical applicability of new medical practices.
Email: ayla.coussa@mail.mcgill.ca