Context: Lipodystrophic HIV patients frequently display impaired pituitary GH response. Objective. To investigate the GH response to GHRH+Arg in women with HIV-related lipodystrophy (HARS) compared with healthy females. To identify possible predictive factors for such a GH response in these patients.
Patients: Forty-nine female patients with HARS were compared with 10 healthy women matched for age and BMI.
Methods: Patients and controls underwent a standard GHRH+Arg test; demographics, anthropometric, metabolic and hormonal variables were evaluated. Basal serum GH, IGF-1, IGFBP-3, glycaemic-lipid profile, GH after GHRH+Arg and HIV disease characteristics were assessed. Body composition was evaluated by DXA in patients and controls, abdominal CT scan being performed only in the HIV patients.
Results: Using cut-offs of 4.2 and 5 ng/ml, 6.12% of the HIV-infected patients failed to reach GH peaks above these values, the percentage increasing to 22.44% with a threshold of 7.5 ng/dl; none of the controls showed a GH peak less than 7.5 ng/dl. IGF-1 was significantly lower in the HIV-infected patients with a GH peak <7.5 ng/dl than in patients with a GH peak >7.5 ng/dl and healthy females. Total lean body mass was the most significant predictive factor for GH peak after GHRH+Arg (r2=0.13), followed by age in the HIV-infected females, while age was the only predictive factor (r2=0.46) in the controls.
Conclusions: The study suggests that relative GH deficiency is common among females with HARS if compared with matched controls, even when the most restrictive thresholds are used. The lack of correlations among GH peak, parameters of fat distribution and low serum IGF-1 in HIV patients suggests that impaired GH secretion may be not related to fat redistribution. Anyhow, these results do not permit to establish definitively whether females with HARS and with impaired GH response to GHRH+Arg are truly or functionally GH deficient.