Knowledge Does Not Correspond to Adherence of Renal Diet Restrictions in Patients With Chronic Kidney Disease Stage 3-5.

OBJECTIVES

Nutrition plays a critical role in delaying the progression of chronic kidney disease (CKD); however, adherence to nutrition recommendation in patients with non-dialysis-dependent CKD (NDD-CKD) has been underexplored. The objective of this research is to determine patients with NDD-CKD adherence to nutrition recommendation, and whether knowledge of dietary recommendations impacts adherence.

DESIGN AND

METHODS

Patients with NDD-CKD and a glomerular filtration rate <45 mL/min were recruited from an urban, outpatient nephrology clinic. To assess adherence, patients completed an online Food Frequency Questionnaire. Knowledge of renal diet restrictions and food sources of sodium, potassium, and phosphorus was assessed by a CKD Knowledge Questionnaire.

RESULTS

A total of 63 patients completed both the Food Frequency Questionnaire and CKD Knowledge Questionnaire. Patients were consuming excess protein (average intake of 1.16 g/kg; 65-81% of patients' intake above goal), sodium (average intake of 3,117 mg, 67-91% of patients' intake above goal), and phosphorus (average intake of 1,153 mg, 59-70% of patients' intake above goal). In patients without hyperkalemia, only 32-43% of patients consumed adequate potassium. People with hyperkalemia did not consume less potassium than those without hyperkalemia (2,327 vs. 2,564 mg, P = .36). Awareness of diet restriction was not associated with reduced intake of phosphorus (785 vs. 907 mg, P = .21), protein (54.4 vs. 57.0 g, P = .71), or potassium (1,793 vs. 2,076 mg, P = .27). Greater knowledge of nutrient food sources did not correlate to reduced intake of sodium (r = -0.078, P = .54) or phosphorus (r = -0.053, P = .68), or potassium in people with hyperkalemia (r = 0.025, P = .92).

CONCLUSIONS

Patients with NDD-CKD consume excess sodium, phosphorus, and protein, whereas potassium intake is inadequate in people without hyperkalemia. Greater knowledge of the renal diet was not associated with increased adherence to dietary restrictions. Instruction efforts should go beyond providing nutrient-based diet information, and instead emphasize healthy food patterns and incorporate counseling to promote behavior change.