title: A brief exposure to moderate passive smoke increases metabolism and thyroid hormone secretion.
abstract: BACKGROUND
  Active smoking influences normal metabolic status and thyroid function.
  
  
  OBJECTIVE
  The objective was to assess experimentally the effects of 1 h of moderate passive smoking in a controlled simulated bar/restaurant environment on the metabolism and thyroid hormone levels in healthy nonsmokers.
  
  
  METHODS
  Eighteen (nine females, nine males) healthy individuals (mean +/- sd: age, 25.3 +/- 3.1 yr; height, 174.0 +/- 10.1 cm; weight, 65.2 +/- 13.7 kg) participated in the study.
  
  
  METHODS
  In repeated-measures randomized blocks, participants visited the laboratory on 2 consecutive days. In the experimental condition, they were exposed to 1 h of moderate passive smoking at a carbon monoxide concentration of 23 +/- 1 ppm in an environmental chamber, whereas in the control condition participants remained in the same chamber for 1 h breathing normal atmospheric air.
  
  
  METHODS
  In both conditions, cotinine serum and urine levels, resting energy expenditure (REE), as well as concentration of T3, free T4, and TSH were assessed before participants entered the chamber and immediately after their exit. Heart rate and blood pressure were tested in 10-min intervals during all REE assessments.
  
  
  RESULTS
  The mean +/- sd difference of serum and urine cotinine levels (-0.27 +/- 3.94 vs. 14.01 +/- 6.54 and 0.05 +/- 2.07 vs. 7.23 +/- 3.75, respectively), REE (6.73 +/- 98.06 vs. 80.58 +/- 120.91) as well as T3 and free T4 (0.05 +/- 0.11 vs. 0.13 +/- 0.12 and 0.02 +/- 0.15 vs. 0.22 +/- 0.20) were increased in the experimental compared with the control condition at baseline and follow-up (P < 0.05). No statistically significant variation was observed in the mean difference of the remaining parameters (P > 0.05). Serum and urine cotinine values were linearly associated with REE (P < 0.05).
  
  
  CONCLUSIONS
  One hour of passive smoking at bar/restaurant levels is accompanied by significant increases in metabolism and thyroid hormone levels.
authors.affiliation: Laboratory of Applied Physiology, Department of Sports and Exercise Science, University of Thessaly, Karies, Trikala GR42100, Greece. gm@wlv.ac.uk
authors.forename: Giorgos S
authors.initials: GS
authors.lastname: Metsios
authors.forename: Andreas D
authors.initials: AD
authors.lastname: Flouris
authors.forename: Athanasios Z
authors.initials: AZ
authors.lastname: Jamurtas
authors.forename: Andres E
authors.initials: AE
authors.lastname: Carrillo
authors.forename: Demetrios
authors.initials: D
authors.lastname: Kouretas
authors.forename: Anastasios E
authors.initials: AE
authors.lastname: Germenis
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Gourgoulianis
authors.forename: Theodoros
authors.initials: T
authors.lastname: Kiropoulos
authors.forename: Manolis N
authors.initials: MN
authors.lastname: Tzatzarakis
authors.forename: Aristeidis M
authors.initials: AM
authors.lastname: Tsatsakis
authors.forename: Yiannis
authors.initials: Y
authors.lastname: Koutedakis
mesh_terms: D000328:Adult; D003367:Cotinine / Q000097:blood / Q000652:urine; D004734:Energy Metabolism; D005260:Female; D006801:Humans; D008297:Male; D013963:Thyroid Hormones / Q000378:metabolism*; D013974:Thyroxine / Q000097:blood; D014028:Tobacco Smoke Pollution / Q000009:adverse effects*; D014284:Triiodothyronine / Q000097:blood
chemical_list: D013963:Thyroid Hormones; D014028:Tobacco Smoke Pollution; D014284:Triiodothyronine; D003367:Cotinine; D013974:Thyroxine