Circulating obestatin is increased in patients with cardiorenal syndrome and positively correlated with vasopressin

Obestatin regulates fluid and electrolyte homeostasis mainly by opposing the action of vasopressin (AVP). We measured plasma concentration of obestatin and AVP in patients with cardiorenal syndrome (CRS). Plasma AVP and obestatin concentration were measured in 34 patients with type II CRS. The data were compared to that in 31 patients with chronic kidney disease (CKD), 41 patients with chronic heart failure (CHF) and 30 healthy subjects. Obestatin was significantly higher in the patients with CRS (355.8 ± 85.1 pg/ml) than that in the healthy controls (212.3 ± 37.9 pg/ml, P<0.01), the patients with CKD (246.7 ± 34.3 pg/ml, P<0.01) and the patients with CHF (258.4 ± 112.1 pg/ml, P<0.01). AVP was also significantly higher in the patients with CRS (65.1 ± 36.0 pg/ml) than that in the healthy controls (38.5 ± 20.1 pg/ml, P<0.01), the patients with CKD (50.4 ± 24.8 pg/ml, P<0.01) and the patients with CHF (54.6 ± 16.3 pg/ml, P<0.01). Plasma concentration of obestatin was positively correlated with AVP plasma concentration in the overall analysis that included subjects from all disease categories (r = 0.219, P<0.05), but not within the CRS group. Plasma obestatin and vasopressin were elevated in patients with CRS. Plasma obestatin concentration seemed to be positively correlated with plasma AVP.