title: Beneficial effects of a long-term oral L-arginine treatment added to a hypocaloric diet and exercise training program in obese, insulin-resistant type 2 diabetic patients.
abstract: Because chronic L-arginine supplementation improves insulin sensitivity and endothelial function in nonobese type 2 diabetic patients, the aim of this study was to evaluate the effects of a long-term oral L-arginine therapy on adipose fat mass (FM) and muscle free-fat mass (FFM) distribution, daily glucose levels, insulin sensitivity, endothelial function, oxidative stress, and adipokine release in obese type 2 diabetic patients with insulin resistance who were treated with a combined period of hypocaloric diet and exercise training. Thirty-three type 2 diabetic patients participated in a hypocaloric diet plus an exercise training program for 21 days. Furthermore, they were divided into two groups in randomized order: the first group was also treated with L-arginine (8.3 g/day), and the second group was treated with placebo. Although in the placebo group body weight, waist circumference, daily glucose profiles, fructosamine, insulin, and homeostasis model assessment index significantly decreased, L-arginine supplementation further decreased FM (P < 0.05) and waist circumference (P < 0.0001), preserving FFM (P < 0.03), and improved mean daily glucose profiles (P < 0.0001) and fructosamine (P < 0.03). Moreover, change in area under the curve of cGMP (second messenger of nitric oxide; P < 0.001), superoxide dismutase (index of antioxidant capacity; P < 0.01), and adiponectin levels (P < 0.02) increased, whereas basal endothelin-1 levels (P < 0.01) and leptin-to-adiponectin ratio (P < 0.05) decreased in the L-arginine group. Long-term oral L-arginine treatment resulted in an additive effect compared with a diet and exercise training program alone on glucose metabolism and insulin sensitivity. Furthermore, it improved endothelial function, oxidative stress, and adipokine release in obese type 2 diabetic patients with insulin resistance.
authors.affiliation: Diabetology, Endocrinology and Metabolic Disease Unit, Fondazione Centro San Raffaele del Monte Tabor, Milan, Italy.
authors.forename: Pietro
authors.initials: P
authors.lastname: Lucotti
authors.forename: Emanuela
authors.initials: E
authors.lastname: Setola
authors.forename: Lucilla D
authors.initials: LD
authors.lastname: Monti
authors.forename: Elena
authors.initials: E
authors.lastname: Galluccio
authors.forename: Sabrina
authors.initials: S
authors.lastname: Costa
authors.forename: Emilia P
authors.initials: EP
authors.lastname: Sandoli
authors.forename: Isabella
authors.initials: I
authors.lastname: Fermo
authors.forename: Giovanni
authors.initials: G
authors.lastname: Rabaiotti
authors.forename: Roberto
authors.initials: R
authors.lastname: Gatti
authors.forename: PierMarco
authors.initials: P
authors.lastname: Piatti
mesh_terms: D000284:Administration, Oral; D001120:Arginine / Q000008:administration & dosage*; D001786:Blood Glucose / Q000378:metabolism; D001794:Blood Pressure; D001835:Body Weight / Q000187:drug effects; D003131:Combined Modality Therapy; D003924:Diabetes Mellitus, Type 2 / Q000178:diet therapy / Q000188:drug therapy*; D004038:Diet, Reducing; D002149:Energy Intake; D015444:Exercise; D005260:Female; D019270:Fructosamine / Q000097:blood; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000178:diet therapy / Q000188:drug therapy*; D014280:Triglycerides / Q000097:blood
chemical_list: D001786:Blood Glucose; D007328:Insulin; D014280:Triglycerides; D019270:Fructosamine; D001120:Arginine