title: Effect of smoking and smoking cessation on bone mass, bone remodeling, vitamin D, PTH and sex hormones.
abstract: OBJECTIVE
  To assess the effect of smoking and smoking cessation on bone density, bone remodeling markers, sex hormones, and vitamin D-PTH axis in healthy young subjects.
  
  
  METHODS
  We studied 74 healthy people (31 men, 43 women; mean age 32.2 (7) years) divided into 52 never smokers and 22 smokers, 15 of which stopped smoking for one month.
  
  
  RESULTS
  Male smokers compared with never smokers showed lower BMD (0.971 (0.11) g/cm(2) vs. 1.069 (0.09) g/cm(2), P=0.042); higher plasma estrone levels (32.37 (10.13) pg/mL vs. 20.91 (5.46) pg/mL, P=0.001); and lower serum iPTH levels (16.2 (3.5) pg/mL vs. 28.8 (2.0) pg/mL, P=0.008). In women, BMD values were similar in smokers than in never smokers, but 25-hydroxyvitamin D levels were lower in smokers (31.9 (15.1) ng/mL vs. 16.8 (9.9) ng/mL, P=0.002). After adjusting by age and coffee consumption, female smokers had higher urinary-NTX levels than never smokers. After smoking cessation, statistically significant decreases of 25-hydroxyvitamin D and SHBG plasma levels were observed in men and women, respectively.
  
  
  CONCLUSIONS
  Tobacco increases bone resorption and affects bone mass by some alterations in sex hormone metabolism, but also importantly by alterations on the vitamin D-PTH axis.
authors.affiliation: Department of Internal Medicine.
authors.forename: A
authors.initials: A
authors.lastname: Supervía
authors.forename: X
authors.initials: X
authors.lastname: Nogués
authors.forename: A
authors.initials: A
authors.lastname: Enjuanes
authors.forename: J
authors.initials: J
authors.lastname: Vila
authors.forename: L
authors.initials: L
authors.lastname: Mellibovsky
authors.forename: S
authors.initials: S
authors.lastname: Serrano
authors.forename: J
authors.initials: J
authors.lastname: Aubía
authors.forename: A
authors.initials: A
authors.lastname: Díez-Pérez
mesh_terms: D000328:Adult; D015519:Bone Density / Q000502:physiology; D016723:Bone Remodeling / Q000502:physiology; D001842:Bone and Bones / Q000502:physiology*; D024042:Collagen Type I / Q000652:urine; D005260:Female; D012739:Gonadal Steroid Hormones / Q000097:blood*; D006801:Humans; D008297:Male; D010281:Parathyroid Hormone / Q000097:blood*; D010455:Peptides / Q000652:urine; D012737:Sex Factors; D012738:Sex Hormone-Binding Globulin / Q000032:analysis; D012907:Smoking / Q000503:physiopathology*; D016540:Smoking Cessation; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood*
chemical_list: D024042:Collagen Type I; D012739:Gonadal Steroid Hormones; D010281:Parathyroid Hormone; D010455:Peptides; D012738:Sex Hormone-Binding Globulin; C052929:collagen type I trimeric cross-linked peptide; D014807:Vitamin D; C104450:25-hydroxyvitamin D