title: The effects of transdermal estrogen therapy on bone mass and turnover in early postmenopausal smokers: a prospective, controlled study.
abstract: OBJECTIVE
  The purpose of this study was to investigate whether smoking reduces the effects of transdermal estrogen replacement therapy on bone.
  
  
  METHODS
  One hundred forty-eight women (0.5-5 years after menopause, aged 46-58 years) completed the study. Smokers were assigned randomly to receive either 1.0 mg (n=32 women) or 1.5 mg (n=31 women) of transdermal estradiol in gel daily, and nonsmokers (n=46 women) were assigned to receive 1.0 mg of transdermal estradiol for 2 years. The control group consisted of 17 smokers and 22 nonsmokers. Bone mineral density was measured by dual-energy x-ray absorptiometry. Bone turnover was assessed by measurements of urinary aminoterminal telopeptide of type I collagen and serum aminoterminal propeptide of type I procollagen.
  
  
  RESULTS
  Lumbar spine bone mineral density increased similarly in smoking (+3.6%) and nonsmoking (+2.6%) estrogen users (P<.0001 to a decrease of 2.5% in the control group). Femoral neck bone mineral density increased 2.2% to 2.4% in smoking and nonsmoking estrogen users but decreased 0.2% in control subjects (P<.05). Urinary aminoterminal telopeptide of type I collagen decreased similarly in all estrogen-using groups (P<.05 to control group), but serum aminoterminal propeptide of type I procollagen decreased more in smoking than in nonsmoking estrogen users (P=.006). Serum 25-hydroxyvitamin D was 20% lower (P=.004) in smokers than in nonsmokers.
  
  
  CONCLUSIONS
  Transdermal estrogen treatment protects smoking women as effectively as nonsmokers from osteoporosis. Smoking worsens the vitamin D state of postmenopausal women.
authors.affiliation: Division of Endocrinology, Department of Medicine, Helsinki University Central Hospital, FIN-00290 Helsinki, Finland. matti.valimaki@hus.fi
authors.forename: Matti J
authors.initials: MJ
authors.lastname: Välimäki
authors.forename: Kalevi A
authors.initials: KA
authors.lastname: Laitinen
authors.forename: Riitta K
authors.initials: RK
authors.lastname: Tähtelä
authors.forename: Erkki J
authors.initials: EJ
authors.lastname: Hirvonen
authors.forename: Juha P
authors.initials: JP
authors.lastname: Risteli
mesh_terms: D000279:Administration, Cutaneous; D015415:Biomarkers / Q000032:analysis; D015519:Bone Density / Q000187:drug effects; D001842:Bone and Bones / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D004958:Estradiol / Q000008:administration & dosage* / Q000097:blood; D015914:Estrogen Replacement Therapy; D005260:Female; D006801:Humans; D008875:Middle Aged; D010024:Osteoporosis / Q000517:prevention & control*; D017698:Postmenopause / Q000097:blood / Q000378:metabolism; D012907:Smoking / Q000009:adverse effects*; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood
chemical_list: D015415:Biomarkers; D014807:Vitamin D; D004958:Estradiol; C104450:25-hydroxyvitamin D