Postprandial Plasma Concentrations of ProANP in Patients with Type 2 Diabetes and Healthy Controls

To the Editor: Atrial natriuretic peptide (ANP)1 plays an important role in blood pressure and intravascular water homeostasis. Together with its biosynthetic precursor proANP, ANP is released from cardiomyocytes in response to dietary sodium and volume overload with concomitant cardiac strain. Recently, ANP secretion was also shown to be stimulated by the incretin hormone glucagon-like peptide-1 (GLP-1) in mice (1). In line with this observation, obesity and diabetes (both types) are associated with lower ANP and proANP concentrations in circulation compared to concentrations in individuals with normal weight. This may suggest that the cardiac natriuretic peptides are involved in metabolic regulation (2). In a recent letter published in this journal, we reported that proANP concentrations in healthy individuals decrease 2 h after meal intake (3). To further elucidate this observation, we examined the plasma proANP response to oral glucose and 3 isocaloric and isovolemic liquid meals in patients with type 2 diabetes (T2D) and matched controls.