title: Evidence for competing effects of body mass, hyperinsulinemia, insulin resistance, and androgens on leptin levels among lean, overweight, and obese women with polycystic ovary syndrome.
abstract: OBJECTIVE
  To evaluate the relationships between leptin, body composition, insulin resistance, androgens, and reproductive indices among women with polycystic ovary syndrome (PCOS).
  
  
  METHODS
  Matched case-control study.
  
  
  METHODS
  Academic reproductive endocrine practice; school of public health.
  
  
  METHODS
  Forty-six Caucasian women with PCOS and 46 population-based controls matched by age and body mass index (BMI).
  
  
  METHODS
  None.
  
  
  METHODS
  Leptin, insulin, androgenic hormones, body composition parameters; reproductive parameters.
  
  
  RESULTS
  Overall, leptin levels among women with PCOS did not differ significantly from those of control women (20.4 +/- 14.9 vs. 21.9 +/- 14.3 ng/mL). However, within the lowest BMI tertile, women with PCOS had significantly lower leptin levels (9.6 vs. 18.3 ng/mL), comparable insulin, and higher testosterone concentrations than controls of similar body mass. Within the overweight and obese subgroups, both insulin and testosterone levels were increased among women with PCOS; leptin levels, although higher among obese cases, were not statistically different than those in controls.
  
  
  CONCLUSIONS
  Below a certain BMI, hyperandrogenic women with PCOS have lower leptin levels than controls. Conversely, overweight and obese PCOS subjects appear to produce insufficient leptin for a given fat mass, relative to the degree of hyperinsulinemia, potentially because of the competing effects of adipocyte insulin resistance and androgens on leptin.
authors.affiliation: Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pennsylvania 15261, USA.
authors.forename: Karen E
authors.initials: KE
authors.lastname: Remsberg
authors.forename: Evelyn O
authors.initials: EO
authors.lastname: Talbott
authors.forename: Jeanne V
authors.initials: JV
authors.lastname: Zborowski
authors.forename: Rhobert W
authors.initials: RW
authors.lastname: Evans
authors.forename: Kathleen
authors.initials: K
authors.lastname: McHugh-Pemu
mesh_terms: D000328:Adult; D001823:Body Composition; D015992:Body Mass Index; D001835:Body Weight; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D006946:Hyperinsulinism; D007333:Insulin Resistance / Q000502:physiology*; D020738:Leptin / Q000097:blood*; D009765:Obesity / Q000097:blood* / Q000150:complications; D010414:Pennsylvania; D011085:Polycystic Ovary Syndrome / Q000097:blood*; D012016:Reference Values; D012098:Reproduction / Q000502:physiology; D013851:Thinness / Q000097:blood* / Q000150:complications; D044465:White People
chemical_list: D020738:Leptin