Elevated serum levels of pancreatic polypeptide are related to impaired glucose handling in inflammatory states.

Glucose handling and insulin secretion were studied in patients with inflammatory connective tissue diseases and correlated to circulating levels of immunoreactive pancreatic polypeptide (PP). The patients had normal fasting serum levels of insulin and normal insulin response to intravenous glucose loading. Ten of 16 patients had an impaired glucose tolerance, defined as a K rate of less than one. The basal PP levels, which were elevated in half of the patients, were inversely correlated to the K values but showed no relationship to basal or maximum insulin levels. The degree of the impaired glucose handling in the patients was related to the degree of the inflammatory activity as defined by acute-phase reactants. Elevated PP levels may be partly responsible for impaired glucose tolerance in inflammatory states either as an inhibitor of peripheral insulin activity or as an inhibitor of hypersecretion of insulin, needed to overcome decreased tissue sensitivity for insulin.