Knowledge of renal diet restrictions in patients with non-dialysis dependent chronic kidney disease stages 3-5

Proper nutrition can delay disease progression and manage complications of non-dialysis dependent chronic kidney disease (NDD-CKD). Little research has investigated knowledge of a renal diet in patients with NDD-CKD stages 3-5. The objective of this paper was to describe knowledge of diet restrictions for sodium, potassium and phosphorus and food sources of these nutrients in patients with NDD-CKD stages 3-5. Patients (n=266) with NDD-CKD and glomerular filtration rate (GFR) less than 45mL/min were recruited from an urban nephrology clinic in the United States. Knowledge of diet restriction and food sources of sodium, potassium and phosphorus were assessed via a questionnaire. Diet restriction knowledge was reported as percent of patients aware of the diet restriction. Food nutrient knowledge was reported as the percentage of foods correctly identified as high in that nutrient. Most patients were aware of the need to limit sodium (96%) and food sources of sodium (77%). Fewer were aware of the need to limit potassium (81% of those with hyperkalaemia) and phosphorus (40%). Knowledge of food sources of potassium (42%) and phosphorus (17%) were poor. Patients with hyperkalaemia were more aware of the potassium diet restriction (p<0.05) than those without. Sodium food knowledge was higher in patients with greater education or living in higher income neighbourhoods (p<0.05). Higher food knowledge scores for all nutrients were found for patients who reported following a diet restriction (p<0.05). Patients with NDD-CKD stages 3-5 are aware of the need to restrict sodium for kidney heath and understand food sources of sodium. However, knowledge of potassium and phosphorus is suboptimal.