The Effect of Dietary Fiber on Hyperkalemia in Maintenance Hemodialysis Patients: A Cross-Sectional Study

To explore the relationship between dietary fiber (DF) intake and hyperkalemia in maintenance hemodialysis (MHD) patients.

A total of 110 MHD patients were included, including 67 males and 43 females. Patients were divided into normal serum potassium group (N) and a hyperkalemia group (H) according to the serum potassium level before dialysis. The daily diet was recorded by the 3-day dietary recording method. The daily dietary nutrient intake of patients was analyzed. Logistic regression was used to analyze the relationship between hyperkalemia and DF intake. A receiver operating characteristic curve was used to analyze the cutoff value of DF intake to prevent hyperkalemia.

Of the 110 patients, 38 had hyperkalemia (serum potassium >5.5 mmol/L) before dialysis. There was no difference in sex, residual kidney function, body mass index, energy intake, fat intake, protein intake, calcium intake, sodium intake, phosphorus intake or the administration history of potassium-lowering drugs between the 2 groups (P > .05). Compared with the H group, patients in the N group had higher carbohydrate intake (315 ± 76 g/d vs. 279 ± 66 g/d, P = .016), dietary fiber intake (19 ± 5 g/d vs. 12 ± 8 g/d, P < .0001), and potassium intake (1,698 ± 392 mg/d vs. 1,533 ± 413 mg/d, P = .041), and more patients in group N used renin-angiotensin-aldosterone system inhibitors (52.78% vs. 23.68%, P = .003). However, the number of patients with constipation in group N was less than that in group H (20.83% vs. 42.11%, P = .018). Logistic regression analysis showed that DF intake was an independent protective factor for hyperkalemia [P < .0001, odds ratio = 0.766 (95% confidence intervals: 0.675-0.870)]. Receiver operating characteristic analysis showed that daily intake of DF greater than 15.33 g may be helpful to prevent hyperkalemia.

Insufficient dietary nutrient intake is prevalent in MHD patients, especially DF intake, which may be associated with hyperkalemia. Clinically, attention should be given to the dietary balance of MHD patients, especially DF intake.