Insulin sensitivity in post-obese women.
1. Both increased and decreased sensitivity to insulin has been proposed to precede the development of obesity. Therefore, insulin sensitivity was measured during a 2 h hyperinsulinaemia (100 m-units min-1 m-2) euglycaemic (4.5 mmol/l) glucose clamp combined with indirect calorimetry in nine weight-stable post-obese women and in nine matched control women preceded by 12 h fasting after 48 h on a standardized diet. 2. Both glucose disposal rate (post-obese women, 9.5 +/- 2.2 mg min-1 kg-1, control women, 11.2 +/- 1.4 mg min-1 kg-1, not significant) and glucose oxidation (3.6 +/- 0.5 mg min-1 kg-1 versus 4.0 +/- 0.7 mg min-1 kg-1, not significant) were similar in the two groups during the last 30 min of the clamp. Lipid oxidation also decreased similarly during the clamp in the post-obese women (from 30.4 +/- 12 to 2.0 +/- 7 J min-1 kg-1) and in the control women (from 33.6 +/- 11 to 5.4 +/- 8 J min-1 kg-1, not significant). Basal plasma concentrations of free fatty acids were similar, but at the end of the clamp free fatty acids were lower in the post-obese women than in the control women (139 +/- 19 and 276 +/- 48 mumol/l, P = 0.02). 3. We conclude that the insulin sensitivity of glucose metabolism is unaltered in the post-obese state. The study, however, points to an increased antilipolytic insulin action in post-obese subjects, which may favour fat storage and lower lipid oxidation rate postprandially.(ABSTRACT TRUNCATED AT 250 WORDS)
Research Department of Human Nutrition, Royal Veterinary and Agricultural University, Frederiksberg, Denmark.
S
S
Toubro
P
P
Western
J
J
Bülow
I
I
MacDonald
A
A
Raben
N J
NJ
Christensen
J
J
Madsen
A
A
Astrup
D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D001835:Body Weight; D002096:C-Peptide / Q000097:blood; D004734:Energy Metabolism / Q000502:physiology; D005260:Female; D005947:Glucose / Q000378:metabolism*; D015309:Glucose Clamp Technique; D006801:Humans; D007328:Insulin / Q000097:blood / Q000502:physiology*; D009765:Obesity / Q000178:diet therapy / Q000235:genetics / Q000378:metabolism*; D010084:Oxidation-Reduction
D001786:Blood Glucose; D002096:C-Peptide; D007328:Insulin; D005947:Glucose