The Changes in Cholinesterase During Overhydration in Hemodialysis Patients

Background/Aim: Overhydration is a serious complication of maintenance hemodialysis patients. Various predictive factors of overhydration have been mentioned, but the role of nutritional condition has not been fully established. We have encountered several cases whose nutritional indices, especially serum cholinesterase (ChE) and serum albumin (Alb), declined one to two months before the onset of overhydration. Then, among cases suffering from overhydration, two groups were divided according to the changes of ChE during before and after 3 months from overhydration attack and were certified the features of both groups concerning cardiothoracic ratio (CTR) and blood pressure as well as body weight changes. Subjects: The subjects were 20 patients suffering from overhydration during maintenance hemodialysis and were hospitalized. Methods: Monthly changes of ChE, Alb, post-dialysis weight, CTR, and blood pressure for 3 months before and after overhydration. Results: Among the 20 patients, 14 had a decrease in ChE values during overhydration, and 6 did not. The ChE-decreased groups tended to have lower BMI, Alb, and ChE than the non-ChE-decreased groups. In the ChE-decreased groups, CTR tended to increase, and ChE and Alb decreased significantly from two months before the onset of overhydration and further increase in CTR (P=0.026) and further decreases in ChE (P<0.001) and Alb (P=0.005) were observed at overhydration attack. Conclusions: In patients with overhydration, there were two types; one is ChE-decreased groups (70%), and the other is non-ChE-decreased groups (30%). Both groups increased CTR and NT-proBNP at overhydration. The former decreased Alb, but latter did not. These results suggested that a decrease in food intake might be the main risk of overhydration and decrease in ChE might be sensitive warning signs for overhydration.