상염색체 우성 다낭신병증 환자에서의 영양평가

Abstract

Introduction: In patients with autosomal dominant polycystic kidney disease (ADPKD), malnutrition may develop as renal function declines and the abdominal organs become enlarged. The nutritional status of ADPKD patients was assessed using Subjective Global Assessment (SGA) and the impact of intra-abdominal mass on nutritional status were investigated. SGA is well validated and known as gold standard method in nutritional assessment. However with non-continuous interrupted scale, BIA has limitation in detecting small changes in nutritional status of a patient during follow up. Bioelectrical Impedance Analysis (BIA) is an objective measurement tool, expected to detect the subtle change of nutritional status by repeating measurements during follow ups. Therefore, in this study BIA was used to assess the efficacy as a nutritional assessment tool compared to SGA and analyzed the correlations with abdominal kidney and liver volume and renal function in ADPKD patients.

Methods: This cross-sectional study was performed at a tertiary hospital outpatient clinic. Anthropometric and laboratory data including serum creatinine, albumin, and cholesterol were collected, and kidney and liver volumes were measured. Total kidney and liver volume was defined as the sum of kidney and liver volume and adjusted by height (htTKLV). Nutritional status was evaluated by using modified SGA, which has been validated in many studies of CKD patients and BIA, a tool used for objective and quantitative nutritional assessment in outpatient clinic. Measurement of BIA was done using Inbody S10, an 8 point tactile multi-frequency segmental BIA. The result of BIA measurement in ADPKD patients were compared with result from healthy population pool after 1:1 matching with age, sex and height.

Results: In a total of 288 patients (47.9% female), the mean age was 48.3±12.2 years and the mean estimated glomerular filtration rate (eGFR) was 65.3±25.3 mL/min/1.73 m2. Of these patients, 21 (7.3%) were mildly to moderately malnourished and 63 (21.7%) were at risk of malnutrition. Overall, patients with or at risk of malnutrition were older, had a lower body mass index, lower hemoglobin levels, and poor renal function compared to the well-nourished group. However, statistically significant differences in these parameters were lost in female patients, except for eGFR. In contrast, a higher htTKLV was correlated with a lower SGA score, even in subjects with an eGFR ≥ 45 mL/min/1.73 m2. Subjects with an htTKLV ≥ 2,340 mL/m showed an 8.7-fold higher risk of malnutrition, after adjusting for sex, age, hemoglobin, albumin, and serum creatinine. BIA was measured in same patients with SGA assessment in outpatient setting and compared with healthy population data. In ADPKD patients, compared to control healthy population, the ratio of extracellular water to total body water (ECW/TBW) of whole body and lower extremity were increased but body fat were decreased. Among BIA parameters, ECW/TBW of whole body, trunk and lower extremity and phase angle (PhA) of lower extremity were related to nutritional status. Using ROC curve analysis for malnutrition, whole body ECW/TBW showed highest area under curve (0.762) with cutoff value >0.389 among BIA parameters. Whole body ECW/TBW can predict malnutrition with OR 9.52 for 0.01 increases after adjusting sex, age, Hgb and either sCr or lnhtTKLV. Trunk ECW/TBW correlated with eGFR (r=-0.307) and lnhtTKLV (r=0.466) the most.

Conclusion: Nutritional risk was detected in 30% of ambulatory patients with ADPKD and relatively good renal function. Intra-abdominal organomegaly affected nutritional status independently from renal function deterioration. In ADPKD patients, segmental BIA can be a useful tool for nutritional assessment. High level of ECW/TBW of whole body, trunk and lower extremity and low level of lower extremity PhA can be used as the indicators for malnutrition in ADPKD patients.