Plasma free fatty acid concentration during hyperglycemic glucose clamp with and without somatostatin infusion in obese subjects with normal glucose tolerance
Zancanaro, C.; Cigolini, M.; Bonora, E.; Moghetti, P.; Cacciatori, V.; Querena, M.; Muggeo, M.
International Journal of Obesity 14(7): 551-557
1990
ISSN/ISBN: 0307-0565 PMID: 1977721 Document Number: 357859
The regulation of plasma free fatty acid (FFA) concentration by glucose and insulin in human obesity was studied. Plasma FFA concentration was estimated in normoglycaemic, normoinsulinaemic obese (n = 8) and non-obese (n = 8) healthy subjects during 240 min of exogenous hyperglycaemia (hyperglycaemic glucose clamp) in glucose-stimulated (0-120 min and 180-240 min) and somatostatin-inhibited (120-180 min) insulin secretion. Plasma FFA curves were approximately parallel in the 0-120 min period and FFA values of obese subjects were constantly higher throughout the experimental period. Moreover, the difference between the 2 groups was significant when individual data were expressed as a percent of fasting FFA value. Plasma insulin levels were similar in the 2 groups. The amount of glucose metabolized during the 80-120 min period was lower in obese than in non-obese subjects (172+or-7 vs. 341+or-11 mg/msuperscript 2.min, P<0.01; mean+or-s.e.). During the somatostatin period (120-180 min) plasma insulin was lowered to basal values in both groups (116+or-15 and 109+or-11 pmol/litre) and plasma FFA concentrations increased in a linear fashion. Data suggest that suppression of plasma FFA concentrations by glucose and insulin is qualitatively similar in healthy non-obese and obese subjects, the latter having higher FFA values. Insulin action on FFA metabolism is not impaired in obese subjects who are insulin resistant.