Apelin, plasmatic osmolality and hypotension in dialyzed patients

To evaluate the balance between arginine-vasopressin (AVP) and apelin during hemodialysis and its role in hypotension onset and in the inflammation status.

We enrolled 50 patients chronically treated with hemodialysis. We assessed plasmatic osmolality, AVP, apelin, mean blood pressure (BP), high-sensitivity C-reactive protein (hsCRP) and β(2)-microglobulin.

Apelin rises during dialytic treatment (from 0.68 ± 0.34 to 1.89 ± 0.56 pg/ml, p < 0.0001), while plasmatic osmolality (from 325 ± 4.54 to 311 ± 1.20 mosm/kg H(2)O, p < 0.0001), AVP (from 4.28 ± 1.12 to 2.48 ± 0.50 pg/ml, p < 0.0001) and mean BP (from 124 ± 6 to 110 ± 7 mm Hg, p < 0.0001) decrease. At multivariate regression with respect to apelin, only mean BP remains (r = -0.95, p < 0.0001). We also correlated the AVP/apelin ratio with BP. Moreover, apelin is inversely related to hsCRP (r = -0.79, p < 0.0001).

The AVP/apelin balance changes with plasmatic osmolality variations induced by hemodialytic sessions and could represent a physiopathological marker of arterial hypo- and hypertension. Finally, apelin appears inversely related to inflammation markers.