Insulin regulation of glucose and lipid metabolism in massive obesity.
Eight obese patients and 12 normal individuals underwent a euglycaemic insulin clamp (20 and 40 mU m2-1.min-1) along with continuous infusion of 3-3H-glucose and 1-14C-palmitate and indirect calorimetry. Basal plasma glucose concentration (4.7 +/- 0.3 vs 4.4 +/- 0.2 mmol/l) was similar in the two groups, whereas hepatic glucose production was slightly higher in obese individuals (1.11 +/- 0.06 vs 0.84 +/- 0.05 mmol/min) in spite of higher plasma insulin levels (17 +/- 2 vs 6 +/- 1 mU/l; p less than 0.01). Insulin inhibition of hepatic glucose production was impaired in obese subjects. Glucose disposal by lean body mass was markedly reduced both at baseline (11.7 +/- 1.1 vs 15.6 +/- 0.6 mumol.kg-1.min-1; p less than 0.05) and during clamp (15.0 +/- 1.1 vs 34.4 +/- 2.8 and 26.7 +/- 3.9 vs 62.2 +/- 2.8 mumol.kg-1.min-1; p less than 0.01) Oxidative (12.2 +/- 1.1 vs 17.8 +/- 1 and 16.1 +/- 1.1 vs 51.1 +/- 1.7 mumol.kg-1.min-1; p less than 0.05-0.002) and non-oxidative glucose metabolism (3.9 +/- 1.1 vs 15.0 +/- 2.8 and 12.8 +/- 3.3 vs 38.2 +/- 2.2 mumol.kg-1.min-1; p less than 0.01-0.001) were impaired. Basal plasma concentrations of non-esterified fatty acids (635 +/- 75 vs 510 +/- 71 mumol/l) and blood glycerol (129 +/- 17 vs 56 +/- 5 mumol/l; p less than 0.01) were increased in obese patients.(ABSTRACT TRUNCATED AT 250 WORDS)
Unit of Metabolic Diseases, University of Padova, Italy.
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Enzi
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Vigili de Kreutzenberg
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Lisato
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Riccio
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Maifreni
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Iori
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Zurlo
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Sergi
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Tiengo
D000328:Adult; D001786:Blood Glucose / Q000378:metabolism*; D001823:Body Composition; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005260:Female; D005947:Glucose / Q000378:metabolism*; D015309:Glucose Clamp Technique; D005990:Glycerol / Q000097:blood*; D006801:Humans; D007332:Insulin Infusion Systems; D007700:Kinetics; D008055:Lipids / Q000097:blood*; D008099:Liver / Q000378:metabolism; D008297:Male; D009767:Obesity, Morbid / Q000097:blood / Q000188:drug therapy* / Q000378:metabolism; D012016:Reference Values
D001786:Blood Glucose; D005230:Fatty Acids, Nonesterified; D008055:Lipids; D005947:Glucose; D005990:Glycerol