title: Abnormal inhibin A and inhibin B secretion in obese women with and without insulin resistance.
abstract: OBJECTIVE
  The present study aimed to establish inhibin A and B serum levels during the menstrual cycle of obese women, and its usefulness as an index of luteal-phase follicular development.
  
  
  METHODS
  Twenty-one obese patients (mean body mass index: 34.9+/-3.7 kg/m2; range: 30.0-45.0 kg/m2) were submitted to basal hormonal measurements and an oral glucose tolerance test after challenge with 75 g glucose. Progesterone and inhibin A and B levels were determined 5-7 days after the menstrual cycle and 7 days prior to expected menses.
  
  
  RESULTS
  As expected, an increase in inhibin A and a decrease in inhibin B were observed when first-phase samples were compared with samples obtained after 15-20 days. On the other hand, the percentage variation of both inhibin A and B was at least four times smaller than the values for normal women described previously by other authors employing the same enzyme-linked immunosorbent assays. A small number of obese women presented ovulatory cycles characterized by progesterone concentration higher than 5.8 ng/ml. The percentage elevation (>190%) of inhibin A in the second samples was in agreement with the progesterone levels, but it seemed to be more sensitive for the detection of follicle luteinization.
  
  
  CONCLUSIONS
  We conclude that obese women present less percentage variation of both inhibin A and B during the menstrual cycle, associated with a low frequency of ovulatory cycles. In obese women, the percentage increase of inhibin A can represent an additional marker to recognize follicle luteinization.
authors.affiliation: Department of Gynecology and Obstetrics, Endocrinology Gynecology Unit, Santa Casa de São Paulo - Faculty of Medical Sciences, São Paulo, Brazil. pedroauge@terra.com.br
authors.forename: Antonio Pedro
authors.initials: AP
authors.lastname: Auge
authors.forename: Carlos Alberto
authors.initials: CA
authors.lastname: Longui
authors.forename: Roberto A
authors.initials: RA
authors.lastname: Almeida Prado
authors.forename: Mylene Neves
authors.initials: MN
authors.lastname: Rocha
authors.forename: Mylene Rocha
authors.initials: MR
authors.lastname: Neves
authors.forename: Andrea
authors.initials: A
authors.lastname: Hirota
authors.forename: Newton Eduardo
authors.initials: NE
authors.lastname: Busso
authors.forename: Osmar
authors.initials: O
authors.lastname: Monte
authors.forename: José Mendes
authors.initials: JM
authors.lastname: Aldrighi
mesh_terms: D000293:Adolescent; D000328:Adult; D015992:Body Mass Index; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood; D005951:Glucose Tolerance Test; D006801:Humans; D007265:Inhibins / Q000378:metabolism*; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D007334:Insulin-Like Growth Factor I / Q000032:analysis; D007986:Luteinizing Hormone / Q000097:blood; D008597:Menstrual Cycle / Q000097:blood; D008875:Middle Aged; D009765:Obesity / Q000503:physiopathology*; D010060:Ovulation; D011374:Progesterone / Q000097:blood; D011446:Prospective Studies; D012738:Sex Hormone-Binding Globulin / Q000032:analysis
chemical_list: D007328:Insulin; D012738:Sex Hormone-Binding Globulin; C422362:inhibin A; C422364:inhibin B; D011374:Progesterone; D007265:Inhibins; D007334:Insulin-Like Growth Factor I; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone