Endocrine Abstracts

Background: SUB:Pituitary – Clinical (Generously supported by IPSEN)GH response to GHRH+Arg is impaired in HIV-infected men and women, compared to gender matched controls. Moreover, reduced GH secretion seems to occur more frequently in HIV-infected males than females.

Methods: To determine gender effects on GH secretion in HIV-infected patients with lipodystrophy, we compared GH/IGF1 status and body composition in 103 males and 97 females. A standardized GHRH+Arg test was performed. Anthropometric measurements were obtained by means of BMI, waist/hip, dual-energy X-ray absorptiometry (DEXA) and abdominal CT scan.

Results: Considering the threshold of GH peak of 7.5 μg/l, 21% of women and 38% of men demonstrated an impaired GH peak. Comparing males and females with insufficient GH peak, they did not differ with regard to BMI, fat mass measured by DEXA (total, at arm, at leg, at trunk) and VAT, SAT and TAT measured by CT. However, men showed higher values of VAT/SAT and VAT/TAT ratios (P<0.05). The intra-gender comparison showed that body composition was not significantly different between women with GH peak ≤7.5 and >7.5 μg/l. Conversely, men with GH deficiency had higher values of trunk fat mass at DEXA and of VAT and TAT at CT (P<0.05), compared to men with normal GH peak.

Conclusions: Impaired GH response to GHRH+Arg is very common in HIV-lipodystrophic subjects. Men demonstrate a higher rate of GH deficiency compared to women. Adipose tissue seems to influence GH peak in males more than in females. However, distribution of adipose tissue more than fat mass per se seems to have a role in the upset of GH/IGF1 status in these patients. Both in men and women body composition changes alone do not fully account for gender differences in GH secretory response in HIV-infected patients. Thus, an impairment of hypothalamic-pituitary function due to other factors (e.g. viral infection, antiretroviral drugs) could not be ruled out.