#4964 ASSOCIATION OF DIETARY INTAKE WITH SERUM LEVELS OF PHOSPHORUS AND POTASSIUM IN THE ELDERLY HEMODIALYSIS PATIENTS IN KOREA

Background and Aims Dietary management of elderly (>60 years old) hemodialysis(HD) patients is very important for solving health problems and improving quality of life. Hyperphosphatemia and hyperkalemia in elderly HD patients are closely related to intake of dietary phosphorus and potassium from Koreans’ unique eating patterns. It is very difficult to manage the diet of hemodialysis patients due to the unique eating patterns of elderly Koreans. In the daily meal pattern, sodium and potassium contents are high in grain-based foods, soups, stews, and seasoned vegetables. And, there are various recipes for meals using a range of condiments, which increase serum phosphorus level. For this reason, it is necessary to educate dietary management using real-time Apps for the elderly in Korea. This study was designed to provide the base data for the development of a self-dietary management App for Korean elderly HD patients. Method This study was conducted on 237 elderly HD patients (149 males and 88 females) at nationwide 18 university hospitals. We collected anthropometric data, biochemical parameters, and dietary data of the subjects. Dietary data for usual intake were obtained by use of a food-frequency questionnaire (FFQ) consisting of 23 food meal items based on the Korean usual diets. For this dietary status evaluation, a newly constructed potassium and phosphorus content DB was used. Results The average age of the patients was 69.7± 11.6 years for men and 69.2±6.9 years for women and the duration of HD was 5.4 ± 4.9 years for men and 5.5±4.2 for women. The mean body mass index (BMI) was 23.24 ± 2.99 kg/m2, mean serum phosphorus level was 5.03 ± 9.59 mg/dl, and mean serum potassium level was 5.41 ± 8.58 mEqL. Hyperphosphatemia (> 4.5 mg/dl) was found in 45.8% of the subjects, and hyperkalemia(> 5.0 mEq/L) in 35.4%. Energy and protein were significantly lower than recommended intakes of HD patients(P = .027, P = .015). Lower intake of energy and protein was more significant in women. The intake of sodium and potassium was significantly higher than recommendation(P = .014, P = .021), which was more excessive in men. Serum phosphorus levels showed positive correlation with intake frequency of mixed grains rice (P = .011), noodle without broth(P = .000), vegetable soup(P = .039), and roasted beef(P = .047) in male patients. In case of female patients, intake of sweet potatoes was correlated with hyperphosphatemia (P = .047). Serum potassium levels showed a positive correlation with intake of Kimchi(P = .000), noodle without broth(P = .000), and ham(P = .018) in men. In women, sweet potatoes(P = .027) and medium-potassium fruits(P = .047) were correlated with serum potassium level. On the other hand, intake of white rice showed negative correlation with serum potassium levels(P = .037) in both sex. Conclusion Dietary management along with medical treatment is essential for maintaining serum phosphorus and potassium levels within acceptable ranges because the composition of the daily routine diet is very unique and varies in Korea. The results of this study showed that the intake of white rice rather than mixed grains is an important factor in sustaining normal serum phosphorus and potassium levels in the elderly Korean HD patients. In addition, limiting intake of sweet potatoes, medium and high potassium vegetables & fruits to under three servings per week is recommended. Therefore, customized dietary management needs to be regulated according to each individual's dietary pattern for the Korean elderly HD patients. Major variables found in this study can be used in the development of new App for customized self-dietary management.