Plasma concentrations of natriuretic peptides in normal cats and normotensive and hypertensive cats with chronic kidney disease

To determine if natriuretic peptide concentrations are increased in cats with systemic hypertension and/or chronic kidney disease (CKD). 22 normal cats, 13 normotensive cats with mild-moderate CKD (NT-CKD), 15 hypertensive cats with mild-moderate CKD (HT-CKD) and 8 normotensive cats with severe CKD (NT-CKD-severe). N-terminal pro-B-type (NT-proBNP) and pro-A-type (NT-proANP) natriuretic peptides were measured in plasma samples from all cats using commercially available assays and concentrations in the normal and diseased groups compared using non-parametric statistical tests. Spearman's rank correlation was used to test for an association between natriuretic peptide and creatinine concentrations. NT-proANP was significantly higher in the NT-CKD-severe than the normal group of cats ( P = 0.006) but there were no other differences between groups. NT-proBNP concentrations were significantly higher in the HT-CKD group than both the normal ( P < 0.001) and the NT-CKD ( P < 0.001) groups. NT-proBNP concentrations were also higher in the NT-CKD-severe ( P < 0.001) and the NT-CKD ( P = 0.005) groups than the normal group. NT-proANP but not NT-proBNP was significantly and positively associated with plasma creatinine concentration. Measurement of NT-proBNP shows promise as a diagnostic marker for systemic hypertension in the cat. Its concentration is not significantly increased in cats with mild-moderate normotensive CKD.