ABSTRACT
Objective To investigate the predictive value of nutritional and fluid status measured by bioelectrical impedance methods for the prognosis of acute kidney injury (AKI) patients undergoing continuous renal replacement therapy (CRRT). Methods Patients with severe AKI received CRRT in the First Affiliated Hospital of Nanjing Medical University from September 2016 to September 2018 were enrolled, and divided into death group and survival group according to 28-day survival. Cox regression was used to analyze the association between 28-day survival and lean tissue index (LTI), fat tissue index (FTI), the ratio of extracellular water (ECW) and body cell mass (BCM) (ECW/BCM), and overhydration (OH), respectively. Results A total of 156 patients were included, including 101 males and 55 females. The age was (62.7 ± 15.4) years, with sequential organ failure assessment (SOFA) score of 9.9±3.9. The 28-day mortality rate was 46.2％. The pre-CRRT OH values in the 28-day survival group and death group were 2.95(1.80, 5.50) L and 4.20(2.95, 5.70) L(P=0.016), and ECW/BCM values were 1.00(0.76, 1.18) and 1.07(0.88, 1.25) (P=0.033), respectively. Univariate Cox regression analysis showed that pre-CRRT high OH values (HR=1.08, 95％CI 1.00-1.17, P=0.040) and high ECW/BCM values (HR=3.02, 95％CI 1.46-6.22, P=0.003) were associated with 28-day death. The changes of OH values (HR=0.83, 95％CI 0.72-0.95, P=0.008) and ECW/BCM values (HR=6.79, 95％CI 1.72-26.82, P=0.006) between pre - CRRT and the 7th day after CRRT initiation were significantly associated with 28-day mortality in patients who survived 7 days after CRRT initiation. After adjusting for age, gender, and SOFA scores, multivariate Cox regression analysis showed that the high OH value (HR=1.16, 95％CI 1.06-1.27, P=0.002) and the high ECW/BCM value (HR=2.80, 95％CI 1.30-6.06, P=0.003) before CRRT, the change of OH value (HR=0.82, 95％CI 0.72-0.95, P=0.008) and ECW/BCM value (HR=2.79, 95％CI 1.30-5.98, P=0.009) between the 7th day after CRRT initiation and pre-CRRT, were independently associated with 28-day death, while LTI (HR=0.93, 95％CI 0.86-1.02, P=0.113) and FTI (HR=0.98, 95％ CI 0.92-1.04, P=0.475) before CRRT were uncorrelated with 28-day death. Conclusions In bioelectrical impedance analysis, the high OH value and high ECW/BCM value before CRRT are associated with 28-day mortality in patients with AKI, while the nutritional indicators LTI and FTI before CRRT are not significantly related. The correction of fluid overload by CRRT within 7 days may reduce the risk of 28-day mortality.
ABSTRACT
Objective@#Currently, parathyroid hormone (PTH) is mainly measured by the second generation intact PTH (iPTH) assay which detects both full-length (1-84)PTH and (7-84)PTH fragments. The third generation whole PTH (wPTH) assay however has turned out to be specific for (1-84) PTH. The aim of this study is to investigate the features of plasma iPTH, (1-84)PTH, (7-84)PTH levels in patients with stage 5 chronic kidney disease (CKD), and evaluate the effects of parathyroidectomy (PTX) on above markers in severe secondary hyperparathyroidism (SHPT) patients.@*Methods@#A cross-sectional study including 90 controls and 233 stage 5 CKD patients, and a prospective follow-up study in 31 severe SHPT patients were conducted. Plasma iPTH and (1-84)PTH levels were measured by the second and third generation assay, respectively. Circulating (7-84)PTH level was calculated by subtracting the (1-84)PTH value from the iPTH value.@*Results@#Plasma levels of iPTH, (1-84)PTH, (7-84)PTH were higher (P<0.01), and (1-84)PTH/iPTH was lower (P<0.01) in stage 5 CKD patients than in controls. For severe SHPT patients with PTX (n=74), plasma iPTH, (1-84)PTH and (7-84)PTH concentrations were significantly increased compared to non-PTX group (n=159) (P<0.01), and the increase of (7-84)PTH level was more striking than (1-84)PTH. Meanwhile, the value of (1-84)PTH/iPTH was decreased (P<0.01). Plasma iPTH level was strongly correlated with (1-84)PTH level (r=0.980, P<0.01) in stage 5 CKD patients. Also, both iPTH and (1-84)PTH levels were positively correlated with serum alkaline phosphatase, dialysis vintage and serum phosphorus (P<0.01). After PTX (median interval of follow-up: 7.1 months), plasma iPTH, (1-84)PTH, (7-84)PTH concentrations were decreased (by 92.9%, 89.7%, 95.8%, P<0.01, respectively) greatly and (1-84)PTH/iPTH was increased (P<0.01).@*Conclusions@#In stage 5 CKD patients, plasma iPTH, (1-84)PTH, (7-84)PTH levels are greatly increased while (1-84)PTH/iPTH is decreased, and PTX can significantly improve abnormality of above markers in severe SHPT patients. The second generation PTH assay overestimates the severity of SHPT, and the accurate measurement of (1-84)PTH by the third assays is more conducive to diagnosis and treatment of CKD and SHPT patients.