title: Smoking reduces breast tenderness during oral estrogen-progestogen therapy.
abstract: OBJECTIVE
  We wished to study the influence of smoking upon the occurrence of breast tenderness during oral estrogen-progestogen therapy (EPT).
  
  
  METHODS
  Data from 626 healthy postmenopausal women participating in three double-blind, randomized, controlled long-term trials of EPT versus placebo were included. The studies covered sequential, continuous and interrupted regimens of estradiol opposed by a selection of progestins. All studies were mono-center studies and performed in the period 1988-1997. Data on breast tenderness were collected from adverse event reporting and information on smoking status was obtained by interview.
  
  
  RESULTS
  Smoking was associated with an earlier age at menopause (difference: 1.3 years, p < 0.001) and a slightly lower body mass index (difference: 0.8 kg/m2, p < 0.01). Smoking women in the EPT groups had significantly lower on-treatment estradiol levels compared to non-smoking women (p < 0.001), whereas no differences were observed in the placebo group. In parallel, the incidence of breast tenderness during EPT was reduced by about one-half (p < 0.001) in smokers compared to non-smokers, whereas no differences were seen on placebo.
  
  
  CONCLUSIONS
  Current smoking reduces the incidence of breast tenderness in women receiving oral EPT. This may be caused by the increased degradation of estradiol during smoking.
authors.affiliation: Center for Clinical & Basic Research, Ballerup, Denmark.
authors.forename: N H
authors.initials: NH
authors.lastname: Bjarnason
authors.forename: C
authors.initials: C
authors.lastname: Jørgensen
authors.forename: H
authors.initials: H
authors.lastname: Kremmer
authors.forename: P
authors.initials: P
authors.lastname: Alexandersen
authors.forename: C
authors.initials: C
authors.lastname: Christiansen
mesh_terms: D015992:Body Mass Index; D001940:Breast / Q000503:physiopathology*; D004958:Estradiol / Q000097:blood; D015914:Estrogen Replacement Therapy / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008875:Middle Aged; D010146:Pain / Q000139:chemically induced / Q000503:physiopathology / Q000517:prevention & control*; D017698:Postmenopause / Q000502:physiology; D016032:Randomized Controlled Trials as Topic; D012907:Smoking / Q000097:blood
chemical_list: D004958:Estradiol