Low copeptin levels in patients with intradialytic hypotension.

BACKGROUND: Intradialytic hypotension (IDH) is related with high morbidity and mortality. There is evidence that arginine-vasopressin (AVP) responses could play a role. Copeptin is the reliable biomarker of AVP. In this study, copeptin, aldosterone, epinephrine, and norepinephrine levels in patients with IDH were evaluated throughout a hemodialysis (HD) session and compared with control group.

METHODS: Study is composed of 15 patients that are normotensive during HD and 15 patients IDH with a minimum HD vintage of 1 year. Blood samples were collected before initiation of HD session (T0 ), in the mid-session for control group, 30 minutes after mean arterial pressure (MAP) drop for IDH patients (T1 ), and at the end of the session (T2 ).

RESULTS: Groups had similar demographic features and health parameters, interdialytic weight gains, and ultrafiltration amounts. IDH group had a MAP decline of 39,9 (±6,4) mmHg. Copeptin levels of control group elevated averagely 79.9 (±97.5) pmol/l at T1 and additionally 24.8 (±33.9) pmol/l at T2 . In IDH group, copeptin level rise at T1 and T2 were 3.2 (±5.5) pmol/l and 34 (±44.6) pmol/l; respectively. Copeptin levels of IDH group were significantly lower at T1 (p<0,001), and at T0 -T2 interval than control group (p=0,05). In control group, aldosterone levels distinctly decreased and, in IDH group, aldosterone levels elevated (p<0,001). Small changes were detected in epinephrine and norepinephrine levels for both groups and did not reach significance (p=0,6 and p=0,3; respectively).

CONCLUSIONS: Lower copeptin level alterations suggest inadequate AVP responses in patients with IDH.