Thermogenic effect of slight hyperglycemia during a lipid infusion.
Resistance to the glucoregulatory action of insulin is a common finding in obesity and may affect thermogenesis. In 13 healthy subjects, we studied the influence of acute insulin resistance induced by a lipid infusion on thermogenesis without any glucose load (n = 4) or during a euglycemic-hyperinsulinemic clamp (n = 5) and an oral glucose tolerance test (OGTT, n = 8). When substrates were not administered at the same time, the energy cost of storage was significantly (P < .05) lower for lipids (3.9%+/-0.9%) than for glucose (11.9%+/-0.5% during the clamp and 14.9%+/-4.0% during the OGTT, NS). The lipid infusion decreased glucose storage during the clamp (control, 3.99+/-0.40 mg x kg(-1) x min(-1); lipid infusion, 0.92+/-0.39; P < .05) but increased it during the OGTT (control, 1.76+/-0.22 mg x kg(-1) x min(-1); lipid infusion, 2.94+/-0.27; P < .05). Infused lipids were stored more (clamp, 3.31+/-0.16; OGTT, 2.65+/-0.11 mg x kg(-1) x min(-1); P < .01) and oxidized less (clamp, 0.64+/-0.21; OGTT, 1.02+/-0.09 mg x kg(-1) x min(-1); P < .05) during the clamp than during the OGTT. When lipids were infused, the energy cost of substrate storage was lower during the clamp versus the OGTT (clamp, 3.2%+/-0.8%; OGTT, 7.3%+/-1.0%; P < .05). This effect was attributed to a lipid-induced impairment of glucose tolerance, which overcomes the inhibitory effect of lipid infusion on glucose storage observed in euglycemia. A slight elevation of plasma glucose in response to a lipid infusion impairs thermogenesis by redirecting the storage of substrates from lipids to glucose, which has a higher energy cost.
Rigalleau
V
V
Service de Nutrition et Diabétologie, Hôpital Haut-lévêque, Pessac, France.
Beylot
M
M
Laville
M
M
Pachiaudi
C
C
Normand
S
S
Nlend
E
E
Gin
H
H
D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D001831:Body Temperature / Q000187:drug effects*; D002153:Calorimetry, Indirect; D004734:Energy Metabolism / Q000187:drug effects; D005260:Female; D015309:Glucose Clamp Technique; D005951:Glucose Tolerance Test; D006801:Humans; D006943:Hyperglycemia / Q000503:physiopathology*; D006946:Hyperinsulinism / Q000097:blood; D007262:Infusions, Intravenous; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D008055:Lipids; D008297:Male; D010084:Oxidation-Reduction
D001786:Blood Glucose; D007328:Insulin; D008055:Lipids