title: Low pulse oxygen saturation in post-menopausal women at high altitude is related to a high serum testosterone/estradiol ratio.
abstract: OBJECTIVE
  The present study was designed to determine if low pulse oxygen saturation (SpO(2)) in post-menopausal women at high altitude was related to high serum testosterone/estradiol (T/E(2)) ratio.
  
  
  METHODS
  Studies were carried out in 191 women living in Cerro de Pasco, Peru (4340 m above sea level) and in 56 women living in Lima (150 m asl). Body weight, height, SpO(2), hematocrit, serum follicle stimulating hormone (FSH), T and E(2) levels were measured in all women. Body mass index (BMI), menopausal status and serum T/E(2) ratio were calculated from data.
  
  
  RESULTS
  At high altitude, the values of SpO(2), serum T, and serum E(2) were significantly lower in post-menopausal than in pre-menopausal women. Hematocrit, serum FSH levels, and serum T/E(2) ratios were significantly higher in post-menopausal women. Serum T and E(2) levels, T/E(2) ratio, SpO(2), and hematocrit levels were not further changed with time after menopause. Women with SpO(2)<85% had lower serum E(2), a higher serum T/E(2) ratio, and higher hematocrit values than women with SpO(2)>90%. At high altitude, multiple regression analysis showed that low SpO(2) was related to menopausal status (-2.6+/-0.83; beta+/-S.E.; P<0.002) and not to chronological age (-0.06+/-0.04; P: NS). Further analysis showed that low SpO(2) was related to high basal serum FSH levels and a high serum T/E(2) ratio in the presence of an interaction between FSH and T/E(2).
  
  
  CONCLUSIONS
  Low values of SpO(2) in women at high altitude were related to a high T/E(2) ratio.
authors.affiliation: Department of Physiological Sciences and Instituto de Investigaciones de la Altura, Universidad Peruana Cayetano Heredia, and Hospital Nacional Cayetano Heredia, Lima, Peru. iiad@upch.edu.pe
authors.forename: G F
authors.initials: GF
authors.lastname: Gonzales
authors.forename: A
authors.initials: A
authors.lastname: Villena
mesh_terms: D000328:Adult; D000368:Aged; D000531:Altitude; D000532:Altitude Sickness / Q000097:blood / Q000503:physiopathology; D016022:Case-Control Studies; D004958:Estradiol / Q000097:blood*; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood; D006400:Hematocrit; D006801:Humans; D008875:Middle Aged; D010092:Oximetry; D010100:Oxygen / Q000097:blood*; D010568:Peru; D017698:Postmenopause / Q000097:blood*; D017697:Premenopause / Q000097:blood; D013739:Testosterone / Q000097:blood*
chemical_list: D013739:Testosterone; D004958:Estradiol; D005640:Follicle Stimulating Hormone; D010100:Oxygen