title: Endocrine and metabolic effects of physiologic r-metHuLeptin administration during acute caloric deprivation in normal-weight women.
abstract: Leptin is a nutritionally regulated hormone that may modulate neuroendocrine function during caloric deficit. We hypothesized that administration of low-dose leptin would prevent changes in neuroendocrine function resulting from short-term caloric restriction. We administered physiologic doses of r-metHuLeptin [(0.05 mg/kg sc daily or identical placebo in divided doses (0800, 1400, 2000, and 0200 h)] to 17 healthy, normal-weight, reproductive-aged women during a 4-d fast. Leptin levels were lower in the placebo-treated group during fasting (3.3 +/- 0.2 vs. 9.6 +/- 1.0 ng/ml, P < 0.001, placebo vs. leptin-treated at end of study). Fat mass decreased more in the leptin than the placebo-treated group (-0.6 +/- 0.1 vs. -0.2 +/- 0.1 kg, P = 0.03). Both overnight LH area (38.9 +/- 21.5 vs. 1.2 +/- 11.1 microIU/ml.min, P = 0.05) and LH peak width increased (15.8 +/- 7.1 vs. -2.3 +/- 6.7 min, P = 0.06) and LH pulsatility decreased (-2.0 +/- 0.9 vs. 1.0 +/- 0.8 peaks/12 h, P = 0.03) more in the leptin vs. placebo group. LH pulse regularity was higher in the leptin-treated group (P = 0.02). Twenty-four-hour mean TSH decreased more in the placebo than the leptin-treated group, respectively (-1.06 +/- 0.27 vs. -0.32 +/- 0.18 microIU/ml, P = 0.03). No differences in 24-h mean GH, cortisol, IGF binding protein-1, and IGF-I were observed between the groups. Hunger was inversely related to leptin levels in the subjects randomized to leptin (r = -0.76, P = 0.03) but not placebo (r = -0.18, P = 0.70) at the end of the study. Diminished hunger was seen among subjects achieving the highest leptin levels. Our data provide new evidence of the important role of physiologic leptin regulation in the neuroendocrine response to acute caloric deprivation.
authors.affiliation: Program in Nutritional Metabolism, Massachusetts General Hospital, Harvard Medical School, 55 Fruit Street, LON 207, Boston, Massachusetts 02114, USA.
authors.forename: Sunita
authors.initials: S
authors.lastname: Schurgin
authors.forename: Bridget
authors.initials: B
authors.lastname: Canavan
authors.forename: Polyxeni
authors.initials: P
authors.lastname: Koutkia
authors.forename: Alex M
authors.initials: AM
authors.lastname: Depaoli
authors.forename: Steven
authors.initials: S
authors.lastname: Grinspoon
mesh_terms: D000328:Adult; D001823:Body Composition / Q000187:drug effects; D001835:Body Weight; D031204:Caloric Restriction; D004311:Double-Blind Method; D004734:Energy Metabolism / Q000187:drug effects; D005260:Female; D006801:Humans; D006815:Hunger; D020738:Leptin / Q000031:analogs & derivatives* / Q000097:blood / Q000494:pharmacology*; D007986:Luteinizing Hormone / Q000097:blood; D013963:Thyroid Hormones / Q000097:blood; D013972:Thyrotropin / Q000097:blood
chemical_list: D020738:Leptin; D013963:Thyroid Hormones; C122136:recombinant methionyl human leptin; D007986:Luteinizing Hormone; D013972:Thyrotropin