MO904: Potassium Intake Does Not Predict High Serum Potassium Levels in Haemodialysis Dash Diet Consumers
Authors: Garagarza Cristina , Valente Ana , Caetano Cristina , Ramos Inês , Sebastião Joana , Pinto Mariana , Oliveira Telma , Anibal A. Ferreira Manuel , Sousa Guerreiro Catarina 
Published: May 2022

Abstract

BACKGROUND AND AIMS
As high serum potassium levels can lead to adverse outcomes in haemodialysis (HD) patients, dietary potassium is frequently restricted in these patients. However, recent studies have questioned whether dietary potassium really affects serum potassium levels. Dietary approaches to stop hypertension (DASH) emphasizes the consumption of potassium rich foods, specially from plant sources, such as: fruits, vegetables, whole grains, nuts and seeds. The aim of this study was to analyze the association between the DASH dietary pattern and serum potassium levels.

METHOD
This was an observational cross-sectional multicentre study with 582 HD patients from 37 dialysis centers. Clinical and biochemical data were registered. Dietary intake was obtained using the Food Frequency Questionnaire. Adherence to DASH dietary pattern was obtained from Fung´s DASH index (8–40 points). For the statistical analysis, Fung´s DASH index was categorized into terciles and mean differences were analyzed with one-way ANOVA. Linear regression was used to analyze the relationship between serum potassium and adherence to the Dash dietary pattern. The multivariate model was adjusted to age, gender, presence of diabetes mellitus, energy intake, dietary potassium intake, residual diuresis, dialysis adequacy (Kt/V), dialysis vintage and intake of potassium binders. All statistical tests were performed using SPSS 26.0 software. A P-value lower than 0.05, was considered statistically significant.

RESULTS
Patients’ mean age was 67.8 ± 17.7 years and median HD vintage was 65 (43–104) months. Mean serum potassium was 5.3 ± 0.67 mEq/L, dietary potassium intake was 2465 ± 1005 mg/day and mean Fung´s Dash Index was 23.9 ± 3.9. Of the whole sample, 36.4% of the patients presented low adherence to the DASH dietary pattern (0–22 points), 39.0% presented a moderate adherence (23–26 points) whereas 24.6% a high adherence (≥27 points).
Comparing to the lower adherence, patients with a higher adherence to the DASH dietary pattern were older (P &lt; 0.005), presented lower serum potassium (P = 0.021), serum sodium (P = 0.028), albumin (P = 0.030), creatinine (P &lt; 0.005), energy intake (P = 0.006), protein intake (P = 0.010), total fat intake (P = 0.001), sodium intake (P &lt; 0.005), lean tissue index (P = 0.006) and higher carbohydrates intake (P = 0.007), fiber intake (P &lt; 0.005), potassium intake (P &lt; 0.005), body mass index (P = 0.002) and fat tissue index (P &lt; 0.005). No differences were observed in potassium binders, Kt/V, C-reactive protein nor haemoglobin. A higher adherence to this dietary pattern was a predictor of lower serum potassium levels (P = 0.004), even in the adjusted model (P = 0.016).

CONCLUSION
Most of the patients presented a moderate adherence to the DASH dietary pattern. Following this dietary pattern, which is rich in potassium, is not associated with increased serum potassium levels in HD patients. What is more, a higher adherence to the DASH dietary pattern predicts lower serum potassium levels. Therefore, tight dietary potassium restrictions may not be adequate, at least for those with a DASH diet plan as a more flexible diet, especially regarding plant-based foods rich in potassium, may promote other health benefits and reduce patient´s dietary plan limitations.