Nephrology Department, Infanta Cristina University Hospital, Badajoz, Spain.
Nefrologia. 2011;31(5):537-44. doi: 10.3265/Nefrologia.pre2011.Apr.10936.
Body composition assessment has the potential to improve the care of patients with chronic kidney disease (CKD). Whole-body multiple-frequency bioimpedance spectroscopy (BIS) appears to be a useful and appropriate technique for assessing hydration status and body composition in CKD patients.
The aims of this study were to determine the hydration status by BIS in patients with advanced CKD, and to analyse the association of body fluid status with common clinical and biochemical characteristics. The prognostic value of the phase angle at 50 KHz (PA) was also evaluated.
The study group consisted of 175 patients (66 ± 14 year, 77 females) with eGFR < 40 ml/min not yet on dialysis. Body composition was assessed by BIS (BCM, Fresenius). Hydration status was expressed as a percentage of the total body water (TBW). Patients were prospectively followed-up for a median of 481 days, and the main determinants of mortality were estimated by Cox regression analysis.
The majority of patients (85%) showed a hydration status within ± 5% TBW. Patients with oedemas or uncontrolled arterial hypertension showed mean estimate fluid overload significantly higher than that of the other study patients. Fluid overload was negatively associated with serum albumin levels, body mass index and urinary sodium/potassium ratio; and positively with male gender and diabetes. During the follow-up period, 16 patients died (9%). The main determinants of mortality adjusted for other potential covariates were: Davies comorbidity index (HR = 4.304; P = .001), and PA (per each °; HR = 0.491; P = .026).
BIS may help identify changes in hydration status in CKD patients not fully appreciated by clinical or biochemical assessment. PA was a significant predictor of mortality in these patients.
人体成分评估有可能改善慢性肾脏病（CKD）患者的治疗效果。全身多频生物阻抗谱（BIS）似乎是一种评估 CKD 患者水合状态和身体成分的有用且合适的技术。
本研究旨在通过 BIS 确定晚期 CKD 患者的水合状态，并分析体液状态与常见临床和生化特征的关系。还评估了 50 KHz 时的相位角（PA）的预后价值。
该研究组包括 175 名 eGFR < 40 ml/min 尚未接受透析的患者（66 ± 14 岁，77 名女性）。身体成分通过 BIS（Fresenius 的 BCM）进行评估。水合状态表示为总水量（TBW）的百分比。前瞻性随访患者中位数为 481 天，并通过 Cox 回归分析估计死亡率的主要决定因素。
大多数患者（85%）的水合状态在± 5% TBW 内。有水肿或未控制的动脉高血压的患者的平均估计液体过载明显高于其他研究患者。液体过载与血清白蛋白水平、体重指数和尿钠/钾比呈负相关，与男性和糖尿病呈正相关。在随访期间，16 名患者死亡（9%）。经其他潜在协变量调整后的死亡主要决定因素为：Davies 合并症指数（HR = 4.304；P =.001）和 PA（每增加 1°；HR = 0.491；P =.026）。
BIS 可帮助识别临床或生化评估不完全了解的 CKD 患者的水合状态变化。PA 是这些患者死亡率的重要预测因素。
