Diet and polycystic kidney disease: A pilot intervention study

Area of Science:

• Nephrology
• Dietary Science
• Clinical Nutrition

Background:

• Dietary factors like sodium, protein, acid precursors, and water intake are implicated in polycystic kidney disease (PKD) cyst growth.
• No prior studies have assessed a comprehensive dietary intervention targeting these factors in patients.

Purpose of the Study:

• To evaluate the feasibility of a diet controlling sodium, protein, acid precursors, and water intake in autosomal dominant polycystic kidney disease (ADPKD) patients.
• To determine if this diet reduces urinary sodium, urea, acid excretion, and urine osmolality.
• To assess patient acceptance and adherence to the dietary intervention.

Main Methods:

• A pilot feasibility study involving 12 adult ADPKD patients serving as their own controls.
• Participants followed their usual diet for one week, followed by a four-week isocaloric diet low in sodium and protein, and high in fruits, vegetables, and water.
• Dietary records, 24-hour urine samples, blood pressure, weight, and serum markers were collected at baseline and during the intervention. A modified nutrition hassles questionnaire assessed feasibility.

Main Results:

• The intervention diet significantly reduced sodium (36%), protein (28%), and acid precursor intake (99%), while increasing fluid intake (42%).
• Urinary excretion of sodium, urea, and net acid decreased by 20%, 28%, and 20%, respectively.
• Urine osmolality and osmoles decreased by 15% and 37%, respectively, with a 35% increase in urine volume. 91% reported manageable dietary hassles.

Conclusions:

• A composite diet low in sodium, protein, and acid precursors, with increased fluid intake, is feasible for adult ADPKD patients.
• The diet successfully altered urinary markers, suggesting potential benefits for managing ADPKD.
• High patient acceptance indicates this dietary approach could be a viable management strategy.