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This Article Full Text Full Text (PDF) All Versions of this Article: 107/1/200    most recent 90812.2008v1 Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Horton, T. J. Articles by Donahoo, W. T. PubMed PubMed Citation Articles by Horton, T. J. Articles by Donahoo, W. T.

Greater systemic lipolysis in women compared with men during moderate-dose infusion of epinephrine and/or norepinephrine

¹Section of Nutrition, Department of Pediatrics, ²Department of Anesthesiology, and ³Division of Endocrinolgy, Diabetes and Metabolism, Department of Medicine, University of Colorado Denver, Aurora, Colorado

Submitted 24 June 2008 ; accepted in final form 23 April 2009

Women have lower circulating catecholamine levels during metabolic perturbations, such as exercise or hypoglycemia, but similar rates of systemic lipolysis. This suggests women may be more sensitive to the lipolytic action of catecholamines, while maintaining similar glucoregulatory effects. The aim of the present study, therefore, was to determine whether women have higher rates of systemic lipolysis compared with men in response to matched peripheral infusion of catecholamines, but similar rates of glucose turnover. Healthy, nonobese women (n = 11) and men (n = 10) were recruited and studied on 3 separate days with the following infusions: epinephrine (Epi), norepinephrine (NE), or the two combined. Tracer infusions of glycerol and glucose were used to determine systemic lipolysis and glucose turnover, respectively. Following basal measurements of substrate kinetics, the catecholamine infusion commenced, and measures of substrate kinetics continued for 60 min. Catecholamine concentrations were similarly elevated in women and men during each infusion: Epi, 182–197 pg/ml and NE, 417–507 pg/ml. There was a significant sex difference in glycerol rate of appearance and rate of disappearance with the catecholamine infusions (P < 0.0001), mainly due to a significantly greater glycerol turnover during the first 30 min of each infusion: glycerol rate of appearance during Epi was only 268 ± 18 vs. 206 ± 21 µmol/min in women and men, respectively; during NE, only 173 ± 13 vs. 153 ± 17 µmol/min, and during Epi+NE, 303 ± 24 vs. 257 ± 21 µmol/min. No sex differences were observed in glucose kinetics under any condition. In conclusion, these data suggest that women are more sensitive to the lipolytic action of catecholamines, but have no difference in their glucoregulatory response. Thus the lower catcholamine levels observed in women vs. men during exercise and other metabolic perturbations may allow women to maintain a similar or greater level of lipid mobilization while minimizing changes in glucose turnover.

sex differences; glucose kinetics; glycerol kinetics