Metabolic effects of fish-oil supplementation in patients with impaired glucose tolerance

Abstract

To determine the impact of fish-oil supplementation on glucose and lipid metabolism in patients with impaired glucose tolerance (IGT), 30 ml fish oil containing 3.8 g eicosapentaenoic acid (EPA; 20:5 omega 3) and 2.5 g docosahexaenoic acid (DHA; 22:5 omega 3) were given to eight obese subjects with IGT (mean +/- SD age 50.3 +/- 8.0 yr) in addition to their regular diet for 2 wk. Studies were performed in randomized order versus an isocaloric control period with a washout phase of 3 wk. Hyperinsulinemic clamp examinations (1 and 10 mU.kg-1.min-1) were performed. Glucose disposal rate (M value) rose from basal 14.3 +/- 5.1 to 17.9 +/- 4.4 mumol.kg-1.min-1 after fish oil (P less than 0.001) during the 1-mU clamp, whereas no change was seen during the 10-mU clamp (without fish oil, 42.2 +/- 8.9 mumol.kg-1.min-1; with fish oil, 45.1 +/- 9.8 mumol.kg-1.min-1;NS). Basal hepatic glucose output remained unaffected by fish oil, whereas fractional glucose clearance after intravenous glucose loading (2.4 mmol/kg body wt, t = 30 min) tended to increase (K value: without fish oil, 2.15 +/- 1.02%/min; with fish oil, 2.74 +/- 1.26%/min; NS). Neither the fasting concentrations of glucose and insulin nor induced glycemia and insulin response during intravenous glucose loading calculated as incremental area under the curve changed after fish-oil supplementation.(ABSTRACT TRUNCATED AT 250 WORDS)