Plasma concentrations of pro-
Atrial natriuretic peptide, proANP, are decreased in
obesity and diabetes. Decreased proANP concentrations have also been noted after meal intake, and recently, a
glucose-mediated regulation of
ANP gene expression was reported. Hence, we evaluated the effects of
insulin,
glucagon and
glucose on plasma proANP in a series of observational and experimental studies. Six healthy men underwent seven days of
bed rest. Before and after the
bed rest, hyperinsulinemic euglycemic clamps with serial plasma measurements of proANP were performed. Moreover, plasma proANP was quantified in 65 individuals with normal or impaired
glucose regulation. Finally, the effects of infusion-induced hyperglucagonemia were examined in ten healthy men.
Bed rest decreased
insulin sensitivity and plasma proANP. The decrease in proANP was not associated with
insulin sensitivity and the
peptide concentrations remained constant during euglycemic
hyperinsulinemia and hyperglycemic hyperglucagonemia. Impaired
glucose regulation was not associated with decreased proANP concentrations.
Bed rest per se induces a marked decrease in plasma proANP concentrations whereas
insulin resistance and impaired
glucose regulation was not associated with lower proANP concentrations. Neither acute
hyperinsulinemia nor hyperglucagonemia seems to affect plasma proANP. Our findings thus suggest that decreased plasma proANP concentrations occur late in the development of
insulin resistance.