Frequency of intake of dietary fiber food groups, its determinants, and the relationship with hyperkalemia in hemodialysis patients in a multicenter study

Abstract

Purpose: Patients undergoing hemodialysis (HD) treatment can have a low intake of dietary fiber-rich food groups to decrease hyperkalemia risk. This multicenter cross-sectional study aimed to investigate the frequency of intake of dietary fiber sources, its determinants, and the relationship with hyperkalemia in HD patients. Methods: HD patients from four dialysis clinics answered a food frequency questionnaire (FFQ) involving the main dietary fiber sources with seven frequency possibilities. The answers were converted into scores. Each score point corresponded to one time per week. Demographic, nutritional, and laboratory data were obtained from the medical records. Univariate analysis was used to assess total score associations, and variables with P<0.20 were included in the regression analysis model.Results: A total of 305 HD patients were included (male: 51%; age: 52.2±14.7 years; hyperkalemia: 29%). The median (interquartile) FFQ scores were as follows: fruits, 6 (2–14); vegetables, 6 (3–10); legumes, 3 (1–7); whole-grain, 0 (0–1); and seeds, 0 (0–0); total score, 19 (14–28). No difference was found between the dietary fiber food groups and total scores with hyperkalemia. Independent predictors of dietary fiber total score were older age, higher HD vintage, higher body mass index (BMI), and higher educational level.Conclusion: The usual frequency of dietary fiber food groups intake was low, and its independent determinants were age, HD vintage, BMI, and education. The lack of association with hyperkalemia suggests that other dietary sources and clinical factors should be considered when managing hyperkalemia in this population.