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

Date Published: April 4, 2019

Publisher: Public Library of Science

Author(s): Hyunjin Ryu, Hayne Cho Park, Hyunsuk Kim, Jongho Heo, Eunjung Kang, Young-Hwan Hwang, Jeong Yeon Cho, Kyu-Beck Lee, Yun Kyu Oh, Kook-Hwan Oh, Curie Ahn, Wisit Cheungpasitporn.


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.

Partial Text

Malnutrition in chronic kidney disease (CKD), also known as protein-energy wasting is one of the strongest predictors of mortality and morbidity [1, 2]. Not only anorexia or inadequate intake of nutrients due to uremic symptoms in CKD patients but also inflammatory conditions and oxidative stress increase malnutrition risk in CKD patients [3]. In previous studies, nutritional markers such as serum albumin, creatinine, body mass index (BMI), and subjective global assessment (SGA) score were independent predictors of death and treatment failure in CKD [4, 5]. Besides, the pre-transplant nutritional status in CKD patients are known to affect the outcomes of kidney transplantation [6, 7]. Therefore, efforts have been made to establish guidelines for proper nutritional assessment and intervention to improve the outcome of CKD patients [8].

This is a cross-sectional study of ambulatory patients who visited the outpatient ADPKD clinic following HOPE-PKD (coHOrt for genotype-PhenotypE correlation in ADPKD) protocol of Seoul National University Hospital. In the HOPE-PKD, a total of Korean 288 ADPKD patients were registered during December 2013 to March. 2014. Inclusion criteria of HOPE-PKD was subjects of 18 years or older and satisfied the Unified Criteria. The nutritional status of ADPKD patients were evaluated using SGA and BIA in our outpatient PKD clinic per standardized protocols. Patients with active cancer, infection, or renal replacement therapy or with a history of liver resection or transplantation were excluded. Detailed clinical information and reasons for liver resection or transplantation are discussed in a previous publication [21].

In a previous study, we found that even in the early stages of CKD, about 30% of patients had SGA score below 6, and that an increased htTKLV was an independent risk factor for malnutrition in ADPKD patients [10]. Therefore, nutritional assessment is important in ADPKD patients, especially for those with large abdominal volume [12]. In addition to SGA, BIA can be used as a nutritional assessment tool, with the advantage of having objective, continuous variables. In ADPKD, with cystic organs, conventional one-cylinder-model BIA might underestimate the TBW, due to the truncal geometry and tissue interfacing [20]. To overcome the limitation of one-cylinder-model BIA in the use of ADPKD patients, we evaluated segmental BIA, which is based on 5-cylinder model, as a quantitative tool for nutritional assessment in ADPKD patients in this study.

These results showed that segmental BIA can be a suitable tool for assessing nutritional status as well as the impact of abdominal cystic organs in ADPKD patients, which provides continuous and segmental parameters.




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