title: Plasma leptin concentrations and lipid profiles during nicotine abstinence.
abstract: BACKGROUND
  Weight gain is a frequent consequence of smoking cessation. Leptin, the protein product of the obese gene, seems to regulate appetite and body fat stores. The purpose of this study was to assess changes in circulating leptin levels and lipid metabolism during nicotine abstinence (NA) and their role in postcessation weight gain.
  
  
  METHODS
  Six sedentary, weight-stable, nonobese adult smokers were studied before and after 7 days of NA while following a weight-maintenance diet of standard composition. All subjects refrained from smoking overnight (as assessed by breath CO) and were instructed to chew nicotine polacrilex gum (4 mg) hourly from 7:00 AM to 8:00 PM [nicotine intake (NI) day]. Venous blood samples were collected at 7:00 AM (after an overnight fast) and 5:00 PM (pre-supper) on NI day and again after 7 days of NA.
  
  
  RESULTS
  Body weight did not change after 7 days of NA (72.0 +/- 2.8 versus 71.8 +/- 2.7 kg). Serum cotinine levels declined from 207 +/- 40 ng/mL during NI to undetectable levels during NA (P < 0.01). Fasting plasma leptin was similar during NI and NA (5.7 +/- 1.4 versus 6.4 +/- 1.9 ng/mL; P = NS). Moreover, plasma concentrations of glucose, insulin, and free fatty acids were unaffected by 7 days of NA. Although plasma triglycerides, total cholesterol, and low-density lipoprotein cholesterol were similar during NI and NA, high-density lipoprotein cholesterol increased by 15% after 7 days of NA (P < 0.05).
  
  
  CONCLUSIONS
  In this group of nonobese, adult smokers consuming an isocaloric diet, NA for 7 days did not affect body weight or circulating concentrations of leptin, glucose, insulin, or free fatty acids. In contrast, HDL cholesterol increased significantly after NA. These results indicate that under controlled dietary conditions, changes in leptin expression do not contribute to the weight gain that commonly accompanies smoking cessation.
authors.affiliation: Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-6303, USA.
authors.forename: A
authors.initials: A
authors.lastname: Oeser
authors.forename: J
authors.initials: J
authors.lastname: Goffaux
authors.forename: W
authors.initials: W
authors.lastname: Snead
authors.forename: M G
authors.initials: MG
authors.lastname: Carlson
mesh_terms: D008076:Cholesterol, HDL / Q000097:blood; D003367:Cotinine / Q000097:blood; D002149:Energy Intake; D005260:Female; D006801:Humans; D020738:Leptin; D008055:Lipids / Q000097:blood*; D008297:Male; D009538:Nicotine / Q000008:administration & dosage / Q000097:blood*; D009765:Obesity / Q000097:blood* / Q000209:etiology; D011446:Prospective Studies; D011506:Proteins / Q000378:metabolism*; D016540:Smoking Cessation; D015430:Weight Gain
chemical_list: D008076:Cholesterol, HDL; D020738:Leptin; D008055:Lipids; D011506:Proteins; D009538:Nicotine; D003367:Cotinine