DAGOGO-JACK, SAMUEL, INDIRA UMAMAHES-WARAN, HASAN ASKARI, AND GUNJAN TYKODI.Leptin response to glucocorticoid occurs at physiological doses and is abolished by fasting. Obes Res. 2003; 11:232-237. Objective: To examine the effects of graded doses of hydrocortisone (HC) on leptin secretion, and determine the effect of fasting.
Research Methods and Procedures:This was a randomized, placebo-controlled, crossover study, with a 1-week "washout" period between interventions. Eight healthy subjects [age ϭ 36 Ϯ 2.3 years (ϮSE), body mass index ϭ 31.5 Ϯ 1.6 kg/m 2 ] completed the dose-response study in which an intravenous infusion of saline (placebo) or HC (30 or 100 mg) was administered for 24 hours. Four healthy subjects (age ϭ 35.2 Ϯ 3.0 years, body mass index ϭ 27.1 Ϯ 2.1 kg/m 2 ) completed the fasting study, which entailed continuous infusion of saline, HC (300 mg/24 hours) in the fed state, or HC (300 mg/24 hours) with total caloric deprivation for 24 hours. Blood sampling was performed every 1 to 2 hours for measurement of leptin, cortisol, insulin, and glucose levels. Results: Peak hyperleptinemia occurred after 16 hours of HC infusion; peak/baseline leptin levels were 129% (placebo), 140% (30 mg of HC for 24 hours, p ϭ 0.05), and 185% (100 mg of HC for 24 hours, p Ͻ 0.01). During infusion of HC (300 mg/24 hours or placebo), the peak/ baseline plasma leptin levels were 16.1 Ϯ 5.8/12.8 Ϯ 5.9 ng/mL (placebo with food, 126%), 14.6 Ϯ 6.0/12.5 Ϯ 6.5 ng/mL (HC fasting, 117%), and 32.5 Ϯ 12.5/12.0 Ϯ 8.4 ng/mL (HC with food, 271%, p Ͻ 0.001). Discussion: Leptin secretory responses occur at physiological doses of HC, are obliterated by fasting, and thus may be of metabolic significance.
