Exogenous insulin sensitivity as well as the dynamics of blood serum levels of immunoreactive insulin and growth hormone (GH) after oral glucose loading were studied in patients with glomerulonephritis of different clinical manifestations and varying renal functions. A correlation between disturbances in carbohydrate metabolism on the one hand, and the degree of renal failure and protein depletion on the other, was established. Disturbances in carbohydrate metabolism were detected as early as in the preazotemic phase of the disease. The clinical significance of the disorders and methods for evaluation of insulin response to oral glucose are discussed.