title: Lorcaserin, a 5-HT(2C) receptor agonist, reduces body weight by decreasing energy intake without influencing energy expenditure.
abstract: BACKGROUND
  Lorcaserin, a selective 5-hydroxytryptamine (5-HT)(2C) receptor agonist, reduces body weight. It is unclear whether weight loss is due to reduced energy intake (EI) or also to enhanced energy expenditure (EE).
  
  
  OBJECTIVE
  This study tested the effect of lorcaserin on EI and EE.
  
  
  METHODS
  In a double-blind, randomized, placebo-controlled trial, 57 (39 women) overweight and obese (body mass index, 27-45 kg/m(2)) adults were randomized to placebo (n = 28) or 10 mg twice daily lorcaserin (n = 29) for 56 d. Weight maintenance was imposed during d 1-7. Beginning on d 8, participants followed a diet and exercise plan targeting a 600 kcal/d deficit.
  
  
  RESULTS
  At baseline and after 7 and 56 d of treatment, we measured body weight, body composition (dual x-ray absorptiometry), blood pressure, heart rate, EI at lunch and dinner, subjective appetite ratings, and 24-h EE and 24-h-respiratory quotient (RQ), measured by indirect calorimetry in a respiratory chamber.
  
  
  RESULTS
  After 7 d of weight maintenance, EI was significantly (P < 0.01) reduced with lorcaserin but not placebo (mean ± sem for lorcaserin, -286 ± 86 kcal; placebo, -147 ± 89 kcal). After 56 d, lorcaserin resulted in significantly larger reductions in body weight (lorcaserin, -3.8 ± 0.4 kg; placebo, -2.2 ± 0.5 kg; P < 0.01), EI (lorcaserin, -470 ± 87 kcal; placebo, -205 ± 91 kcal; P < .05), and appetite ratings than in placebo. Changes in 24-h EE and 24-h RQ did not differ between groups, even after 24-h EE was adjusted for body weight and composition. Compared with placebo, lorcaserin had no effect on systolic or diastolic blood pressure or heart rate after 56 d.
  
  
  CONCLUSIONS
  Lorcaserin reduces body weight through reduced EI, not altered EE or RQ.
authors.affiliation: Pennington Biomedical Research Center, 6400 Perkins Road, Baton Rouge, Louisiana 70808, USA.
authors.forename: Corby K
authors.initials: CK
authors.lastname: Martin
authors.forename: Leanne M
authors.initials: LM
authors.lastname: Redman
authors.forename: Jinkun
authors.initials: J
authors.lastname: Zhang
authors.forename: Matilde
authors.initials: M
authors.lastname: Sanchez
authors.forename: Christen M
authors.initials: CM
authors.lastname: Anderson
authors.forename: Steven R
authors.initials: SR
authors.lastname: Smith
authors.forename: Eric
authors.initials: E
authors.lastname: Ravussin
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001066:Appetite / Q000187:drug effects; D001552:Benzazepines / Q000009:adverse effects / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D001823:Body Composition / Q000187:drug effects; D015992:Body Mass Index; D001835:Body Weight / Q000187:drug effects*; D004311:Double-Blind Method; D002149:Energy Intake / Q000187:drug effects*; D004734:Energy Metabolism / Q000187:drug effects*; D005260:Female; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology; D006801:Humans; D008055:Lipids / Q000097:blood; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology; D009765:Obesity / Q000188:drug therapy / Q000523:psychology; D050177:Overweight / Q000188:drug therapy / Q000523:psychology; D010084:Oxidation-Reduction; D044405:Receptor, Serotonin, 5-HT2C / Q000187:drug effects*; D017366:Serotonin Receptor Agonists / Q000009:adverse effects / Q000494:pharmacology*; D011795:Surveys and Questionnaires; D055815:Young Adult
chemical_list: D001552:Benzazepines; D008055:Lipids; D044405:Receptor, Serotonin, 5-HT2C; D017366:Serotonin Receptor Agonists; C506658:lorcaserin