Objective:

To determine the effects of gender, race, and fat redistribution on growth hormone (GH) secretory patterns in HIV-infected patients.

Design:

We investigated GH responses to growth hormone releasing hormone (GHRH)+ arginine stimulation testing in HIV-infected subjects with fat redistribution, comparing HIV-infected males (n= 139) and females (n= 25) to non HIV-infected male (n= 25) and female (n= 26) control subjects similar in age, body mass index and race.

Methods:

A standard GHRH+ arginine stimulation test [GHRH 1 μg/kg and arginine 0.5 g/kg (maximum dose 30 g)] was performed, and fat redistribution was assessed by anthropometry.

Results:

HIV-infected women had significantly higher peak GH in response to GHRH+ arginine (36.4±7.3 versus 18.9±2.0 ng/ml; P= 0.003) and GH area under curve (AUC)(2679±593 versus 1284±133 (mg-min)/dl, P< 0.001) compared to HIV-infected men. Among men, a cutoff of 7.5 ng/ml for peak GH response on the GHRH+ arginine test achieved good specificity and sensitivity and optimally separated the HIV and control groups (eg, the failure rates were 37% versus 8%; P= 0.004, respectively). Among women, no specific cutoff could be determined to separate the HIV-infected and control subjects. Non-Caucasians demonstrated a higher GH AUC response compared to Caucasians, among the HIV-infected male subjects. In stepwise regression modeling waist-to-hip ratio was most significantly related to peak GH in response to GHRH+ arginine in HIV-infected men.

Conclusions:

HIV-infected men with fat redistribution have significantly reduced GH peak responses and increased failure rates to standardized GH stimulation testing in comparison to healthy male control subjects and to HIV-infected women of similar age and body mass index. GH secretion is related to gender and race in HIV-infected patients.