Bioelectrical impedance analysis as a nutritional assessment tool in Autosomal Dominant Polycystic Kidney Disease

Autosomal dominant polycystic kidney disease (ADPKD) patients with massive organomegaly suffer from pressure-related complications including malnutrition. In this study, we analyzed the efficacy of segmental bioelectrical impedance analysis (BIA) for objective and quantitative nutritional assessment in ADPKD patients.

We conducted a cross-sectional study, to evaluate the clinical utility of segmental BIA for assessing the nutritional status of ADPKD patients. BIA measurements was assessed according to modified subjective global assessment (SGA) scores and were compared with data from a healthy population. The association between BIA measurements and the height adjusted kidney and liver volumes (htTKLV), were analyzed.

A total of 288 ADPKD patients, aged ≥ 18 years old, were analyzed.

Nutritional status was evaluated with SGA and segmental BIA. The htTKLV were measured in each patients using computed tomonography images.

Higher ratios of extracellular water to total body water (ECW/TBW) in the whole-body (ECW/TBWWB), trunk (ECW/TBWTR), and lower extremities (ECW/TBWLE) and lower phase angle of lower extremities (PhALE) correlated with lower SGA scores in the ADPKD population and in both gender. The four parameters, ECW/TBWWB, ECW/TBWTR, and ECW/TBWLE of >0.38 and PhALE of <5.8 θ were associated with malnutrition in ADPKD patients. These correlations were preserved in the subgroup analysis for chronic kidney disease stages 1-3A. Compared to healthy populations' data, body fluid parameters and segmental ECW/TBW values, except for the upper extremities (ECW/TBWUE), were greater in ADPKD patients. Increased htTKLV was an independent risk factor for malnutrition in ADPKD. The highest correlation with htTKLV was observed for the ECW/TBWTR (r = 0.466), followed by ECW/TBWWB (r = 0.407), ECW/TBWLE (r = 0.385), PhALE (r = -0.279), and PhATR (r = 0.215).

These results demonstrated that segmental BIA parameters of ECW/TBWWB, ECW/TBWTR, ECW/TBWLE and PhALE provide useful information on nutritional status including the impact of organomegaly in ADPKD.