Plasma proANP Decreases after Meal Intake

To the Editor:Cardiac natriuretic peptides and their molecular precursor fragments are sensitive plasma markers of congestive heart failure and left ventricular dysfunction. Most studies on their value as markers in cardiac diseases have also addressed the effects of aging and sex, in which increasing age and female sex are associated with higher concentrations per se and thus are recommended to be included in establishing reference intervals. Biological variation has also been associated with the circadian pattern of cardiac natriuretic peptide mRNA contents in mice and the concomitant plasma concentrations in humans.New findings have demonstrated that natriuretic peptides and their receptors are involved in fat and muscle metabolism (1). These data, combined with the observation that obese people display lower plasma concentrations than individuals of normal weight, suggest that cardiac natriuretic peptides are also involved, for instance, in the metabolic syndrome and perhaps even in diabetes. No study thus far has tested whether plasma concentrations of pro–atrial-type natriuretic peptide (proANP)1 and pro–brain-type natriuretic peptide (BNP) may be affected by meal intake, a standard stimulus for the gastrointestinal output of hormones involved in glucose metabolism. Therefore, …