title: Cigarette smoking, estrogen levels, and hot flashes in midlife women.
abstract: OBJECTIVE
  The aims of this study were to examine the association of smoking with the occurrence, frequency, and severity of hot flashes and to determine whether the mechanism by which active cigarette smoking increases the risk of hot flashes is by lowering estradiol and estrone levels.
  
  
  METHODS
  A case-control study was conducted among women aged 45-54 years to examine risk factors for hot flashes. Cases were women who reported ever experiencing hot flashes (n = 353). Controls were women who reported never experiencing hot flashes (n = 258). Each participant completed a questionnaire and provided a blood sample that was used to measure estradiol and estrone levels.
  
  
  RESULTS
  The results showed that both current and ever smokers had higher odds than never smokers of experiencing any and more severe hot flashes. Further, significant positive associations were observed between frequency and duration of smoking and the experiencing of any and more severe hot flashes. Smoking was not associated with estradiol or estrone levels in univariate analyses. In addition, the odds ratios for the associations between the cigarette smoking variables and hot flashes did not change when the hormone variables were added to the model.
  
  
  CONCLUSIONS
  These findings indicate that smoking is associated with the occurrence of any and more severe hot flashes, independent of estrogen levels.
authors.affiliation: Department of Epidemiology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD 21205, USA.
authors.forename: Lisa
authors.initials: L
authors.lastname: Gallicchio
authors.forename: Susan R
authors.initials: SR
authors.lastname: Miller
authors.forename: Kala
authors.initials: K
authors.lastname: Visvanathan
authors.forename: Lynn M
authors.initials: LM
authors.lastname: Lewis
authors.forename: Janice
authors.initials: J
authors.lastname: Babus
authors.forename: Howard
authors.initials: H
authors.lastname: Zacur
authors.forename: Jodi A
authors.initials: JA
authors.lastname: Flaws
mesh_terms: D015142:Baltimore / Q000453:epidemiology; D015992:Body Mass Index; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D004522:Educational Status; D004958:Estradiol / Q000097:blood*; D004970:Estrone / Q000097:blood*; D005260:Female; D019584:Hot Flashes / Q000097:blood / Q000453:epidemiology / Q000209:etiology*; D006801:Humans; D008593:Menopause; D008875:Middle Aged; D016017:Odds Ratio; D012307:Risk Factors; D012720:Severity of Illness Index; D012907:Smoking / Q000009:adverse effects / Q000097:blood / Q000453:epidemiology; D011795:Surveys and Questionnaires
chemical_list: D004970:Estrone; D004958:Estradiol