Circulating growth hormone, insulin-like growth factor I, cortisol and free thyroxine in children with schistosomiasis with and without hepatic fibrosis.

Serum insulin, growth hormone (GH), cortisol, free thyroxine (T4) and plasma insulin-like growth factor I(IGF-I) concentrations were measured in 20 children suffering from schistosomiasis as well as 10 healthy age-matched controls. Circulating GH and insulin levels were determined after an intravenous infusion of arginine HCl (10 per cent solution, 0.5 g/kg). Children with schistosomal hepatic fibrosis (n = 10) had heights more than 2 SD below the mean for their age and sex. Their circulating IGF-I, free T4, and cortisol levels were significantly reduced. They had markedly elevated serum insulin concentrations with normal response to arginine infusion. Their basal GH levels were normal with significantly reduced GH response to arginine provocation. Compared to controls, they had significantly lower serum albumin concentrations, prolonged prothrombin time and elevated alanine transferase (ALT) levels. Free T4 and IGF-I concentrations, and GH increments after provocation correlated significantly with the percentile heights of these patients (r = 0.90, 0.70, and 0.83, P less than or equal to 0.001, less than or equal to 0.05 and less than or equal to 0.01 respectively). Their IGF-I levels correlated closely with the prothrombin time and ALT concentrations (r = 0.87 and 0.77, P less than or equal to 0.002 and less than or equal to 0.01, respectively). It is suggested that the depressed circulating IGF-I and free T4 levels in addition to deficient GH reserve may be responsible for stunted stature in patients with schistosomal hepatic fibrosis.