title: Testosterone concentrations in young pubertal and post-pubertal obese males.
abstract: OBJECTIVE
  Obesity in adult males is associated with hypogonadotropic hypogonadism. We evaluated the effect of obesity on plasma testosterone concentrations in pubertal and post-pubertal young males.
  
  
  METHODS
  Morning fasting blood samples were obtained from 25 obese [body mass index (BMI) ≥95th percentile] and 25 lean (BMI <85th percentile) males between the ages 14-20 years with Tanner staging ≥4. Total (TT) and free testosterone (FT) and estradiol concentrations were measured by liquid chromatography tandem mass spectrometry and equilibrium dialysis. Free testosterone was also calculated using SHBG and albumin. C-reactive protein (CRP), insulin and glucose concentrations were measured and homoeostasis model of insulin resistance (HOMA-IR) was calculated.
  
  
  RESULTS
  After controlling for age and Tanner staging, obese males had a significantly lower total testosterone (10·5 vs 21·44 nmol/l), free testosterone (0·22 vs 0·39 nmol/l) and calculated free testosterone (0·26 vs 0·44 nmol/l) concentrations as compared to lean males (P < 0·001 for all). Obese males had higher CRP concentrations (2·8 vs 0·8 mg/l; P < 0·001), and HOMA-IR (3·8 vs 1·1; P < 0·001) than lean males. Free testosterone concentrations were positively related to age and negatively to BMI, HOMA-IR and CRP concentrations. Total and free estradiol concentrations were significantly lower in males with subnormal testosterone concentrations.
  
  
  CONCLUSIONS
  Testosterone concentrations of young obese pubertal and post-pubertal males are 40-50% lower than those with normal BMI. Obesity in young males is associated with low testosterone concentrations, which are not secondary to an increase in estradiol concentrations. Our results need to be confirmed in a larger number of subjects.
authors.affiliation: Division of Pediatric Endocrinology, Department of Pediatrics, State University of New York at Buffalo, Buffalo, NY, USA.
authors.forename: Muniza
authors.initials: M
authors.lastname: Mogri
authors.forename: Sandeep
authors.initials: S
authors.lastname: Dhindsa
authors.forename: Teresa
authors.initials: T
authors.lastname: Quattrin
authors.forename: Husam
authors.initials: H
authors.lastname: Ghanim
authors.forename: Paresh
authors.initials: P
authors.lastname: Dandona
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D015992:Body Mass Index; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D006801:Humans; D008297:Male; D009765:Obesity / Q000097:blood* / Q000453:epidemiology; D011627:Puberty / Q000097:blood* / Q000502:physiology; D013739:Testosterone / Q000097:blood*; D013851:Thinness / Q000097:blood / Q000453:epidemiology; D055815:Young Adult
chemical_list: D013739:Testosterone