title: Gender differences in GH response to GHRH+ARG in lipodystrophic patients with HIV: a key role for body fat distribution.
abstract: OBJECTIVE
  Gender influence on GH secretion in human immunodeficiency virus (HIV)-infected patients is poorly known.
  
  
  METHODS
  To determine the effect of gender, we compared GH response to GH-releasing hormone plus arginine (GHRH+Arg), and body composition in 103 men and 97 women with HIV and lipodystrophy. The main outcomes were IGF1, basal GH, GH peak and area under the curve (AUC) after GHRH+Arg, body composition, visceral adipose tissue (VAT), and subcutaneous adipose tissue (SAT).
  
  
  RESULTS
  Men had lower GH peak and AUC than women (P<0.001). Of the study population, 21% of women and 37% of men had biochemical GH deficiency (GHD; GH peak <7.5 μg/l). VAT-to-SAT ratio was higher in men than in women with GHD (P<0.05). Unlike women, VAT, SAT, and trunk fat were greater in men with GHD than in men without GHD. IGF1 was significantly lower in women with GHD than in women without GHD, but not in men. At univariate analysis, BMI, trunk fat mass, VAT, and total adipose tissue were associated with GH peak and AUC in both sexes (P<0.05). BMI was the most significant predictive factor of GH peak, and AUC at multiregression analysis. Overall, abdominal fat had a less pronounced effect on GH in females than in males.
  
  
  CONCLUSIONS
  These data demonstrate that GH response to GHRH+Arg is significantly lower in HIV-infected males than females, resulting in a higher percentage of GHD in men. Adipose tissue distribution more than fat mass per se seems to account for GH gender differences and for the alteration of GH-IGF1 status in these patients.
authors.affiliation: Chair of Endocrinology and Metabolism, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy.
authors.forename: Giulia
authors.initials: G
authors.lastname: Brigante
authors.forename: Chiara
authors.initials: C
authors.lastname: Diazzi
authors.forename: Anna
authors.initials: A
authors.lastname: Ansaloni
authors.forename: Lucia
authors.initials: L
authors.lastname: Zirilli
authors.forename: Gabriella
authors.initials: G
authors.lastname: Orlando
authors.forename: Giovanni
authors.initials: G
authors.lastname: Guaraldi
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Rochira
mesh_terms: D050153:Abdominal Fat / Q000473:pathology*; D050154:Adiposity; D000328:Adult; D001120:Arginine; D001823:Body Composition; D015992:Body Mass Index; D015331:Cohort Studies; D005260:Female; D013007:Growth Hormone-Releasing Hormone; D039682:HIV-Associated Lipodystrophy Syndrome / Q000097:blood / Q000473:pathology* / Q000503:physiopathology*; D019382:Human Growth Hormone / Q000097:blood / Q000172:deficiency / Q000378:metabolism*; D006801:Humans; D007018:Hypopituitarism / Q000209:etiology*; D007334:Insulin-Like Growth Factor I / Q000032:analysis; D050152:Intra-Abdominal Fat / Q000473:pathology; D008297:Male; D010903:Pituitary Gland, Anterior / Q000378:metabolism* / Q000503:physiopathology; D011446:Prospective Studies; D012727:Sex Characteristics; D050507:Subcutaneous Fat, Abdominal / Q000473:pathology
chemical_list: C583557:IGF1 protein, human; D019382:Human Growth Hormone; D007334:Insulin-Like Growth Factor I; D013007:Growth Hormone-Releasing Hormone; D001120:Arginine