J ZHANG1,2, C MANNIX1, C WOOLNOUGH3, GK RANGAN1, A RANGAN2, ATY WONG1
1Centre for Transplant and Renal Research, Westmead Institute for Medical Research, University of Sydney, Westmead, NSW; 2School of Life and Environmental Sciences, Charles Perkins Centre, University of Sydney, Camperdown, NSW; 3Department of Chemical Pathology, Royal Prince Alfred Hospital, Camperdown, NSW
Aim: To analyse the usual food and nutrient intake of an Australian population of patients with autosomal dominant polycystic kidney disease (ADPKD).
Background: Dietary factors have been associated with cyst growth, renal function and disease progression.
Methods: A structured diet history interview was used to obtain usual intake over 3 months from 29 participants (21-61 y). Nutrient intakes were compared to the KHA-CARI ADPKD Diet and Lifestyle Management Guidelines. A twenty-four-hour urine collection and blood sample were collected to measure urinary sodium and serum copeptin (B.R.A.H.M.S. assay).
Results: Mean (SD) daily nutrient intakes were: energy 8529 (2338) kJ; protein 1.5 (0.7) g/kg body weight; sodium 97 (43) mmol; caffeine 119 (90) mg and fluid 3154 (1403) g. Seventy-nine percent of participants exceeded protein recommendations (1.0 g/kg body weight/d); 31% (41% males, <1% females) exceeded sodium recommendations (100 mmol/d); and 17% exceeded caffeine recommendations (200 mg/d). Average total fluid intake was comprised of 46% plain water, 28% other beverages and 26% solid food. Recommendations from the Australian Dietary Guidelines (ADG) for total fluid (from food and beverages) and for fluid from beverages only were not met by 62% and 66% of participants, respectively. Consumption of vegetables and dairy was low with 79% and 90% not meeting the ADG recommended serves, respectively. Excluding Stage 3 CKD patients, mean 24-h urinary sodium excretion (145 (71) mmol) had a weak correlation with reported sodium intake (r=0.363; P=0.089) and a strong correlation with serum copeptin (r=0.772; P<0.001).
Conclusions: The usual diet of ADPKD patients does not comply with current recommendations. Targeted interventions to reduce protein and sodium intake, increase consumption of vegetables and dairy and increase fluid intake are warranted.