title: Postmenopausal osteoporosis is more related to hormonal aberrations than to lifestyle factors.
abstract: OBJECTIVE
  Serum insulin-like growth factor-1 (IGF-1) decreases with increasing age and this process is more pronounced in women after the menopause in parallel with the increasing prevalence of osteoporosis. This study was designed to compare IGF-1 concentrations, vitamin D, intact parathyroid hormone (PTH) and lifestyle factors in postmenopausal, osteoporotic women with and without oestrogen replacement therapy (HRT), with an age-matched random population sample of women.
  
  
  METHODS
  Case control study.
  
  
  METHODS
  Postmenopausal, osteoporotic women, n = 128, mean age 59 +/- 6 years, were compared with a female random population sample matched for age, n = 227, mean age 59 +/- 5 years, from the WHO MONICA Project, Göteborg, Sweden. Osteoporotic fractures had occurred in 56% of the patients compared with 4% of the controls (P < 0.001).
  
  
  METHODS
  Anthropometry, occupation, smoking habits, physical activity, blood pressure, IGF-1, vitamin D, intact PTH, blood lipids.
  
  
  RESULTS
  There were no differences in occupational class, current or previous smoking habits, degree of physical activity during occupational or leisure time between the patients and controls. Osteoporotic women had lower body weight and body mass index than the controls (P < 0.001). Height, waist/hip ratio and osteocalcin were similar. 25(OH) vitamin D and 1,25(OH)2 vitamin D were lower (P < 0.05 and P < 0.01, respectively), PTH was higher (P < 0.001) and IGF-1 lower (P < 0.01) in osteoporotic women compared with the controls. IGF-1 was lower (P < 0.05), in spite of similar bone mineral density, in osteoporotic women without HRT than in those with HRT, who had IGF-1 concentrations similar to those of the population sample, of whom fewer than 10% had HRT. Among patients, IGF-1 did not correlate with serum oestradiol or bone mineral density. PTH correlated negatively to bone mineral density at the femoral site (r = - 0.29; P = 0.003).
  
  
  CONCLUSIONS
  Osteoporosis in postmenopausal women is more related to hormonal aberrations than to lifestyle factors.
authors.affiliation: Research Centre for Endocrinology and Metabolism, Department of Medicine, Sahlgrenska University Hospital, Göteborg, Sweden. kerstin.landin@sahlgrenska.se
authors.forename: K
authors.initials: K
authors.lastname: Landin-Wilhelmsen
authors.forename: L
authors.initials: L
authors.lastname: Wilhelmsen
authors.forename: B A
authors.initials: BA
authors.lastname: Bengtsson
mesh_terms: D015992:Body Mass Index; D001835:Body Weight; D015519:Bone Density; D002112:Calcifediol / Q000097:blood*; D002117:Calcitriol / Q000097:blood*; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D015444:Exercise; D005260:Female; D020249:Hormone Replacement Therapy; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D008019:Life Style; D008875:Middle Aged; D015663:Osteoporosis, Postmenopausal / Q000097:blood / Q000209:etiology*; D010281:Parathyroid Hormone / Q000097:blood; D012907:Smoking / Q000097:blood
chemical_list: D010281:Parathyroid Hormone; D007334:Insulin-Like Growth Factor I; D002117:Calcitriol; D002112:Calcifediol