Hyperparathyroidism in hepatobiliary disease in infancy.

Metabolism of calcium and magnesium may be disturbed in hepatobiliary disease because of deficient or absent bile flow into the gut, since bile is important for the intestinal absorption of these elements. In the present paper the tubular reabsorption of phosphate (TRP), calcium (TRCa), and magnesium (TRMg) were determined in an attempt to evaluate the parathyroid function of infants and children with hepatobiliary disease. In unrepaired biliary atresia TRP was conspicuously reduced (mean 49.8%, SD 15.1). In successfully repaired biliary atresia the value was increased near the normal range (mean 80.7%, SD 8.1). In neonatal hepatitis the value was variable in individual cases, but significantly lower than the normal (mean 47.6%, SD 19.9). TRCa was reduced in one third of the patients with unrepaired biliary atresia and in one fifth of the cases of neonatal hepatitis. The value was within the normal range in repaired biliary atresia. TRMg was decreased in both unrepaired and repaired biliary atresia and in neonatal hepatitis. The effect of intravenous calcium infusion on TRP, TRCa and TRMg was evaluated in 3 patients with unrepaired biliary atresia. TRP was conspicuously enhanced after infusion. TRCa was decreased in 3 to a variable extent. TRMg was moderately increased in 2 and greatly decreased in 1. These results indicate that infants with hepatobiliary disease are in a state of secondary hyperparathyroidism because of deficient or absent bile flow into the intestines.