Clinical Value Research Of Peritoneal Dialysis Effluent Aquaporin-1 In Peritoneal Dialysis

Objective:To investigate whether there are differences in peritoneal dialysis effluent aquaporin-1(AQP1)level in continuous ambulatory peritoneal dialysis(CAPD)patients with different peritoneal transport types and different ultrafiltration,and the correlation between AQP1 level and peritoneal transport status and ultrafiltration,and to explore whether peritoneal dialysis effluent AQP1 can be used to assess peritoneal transport function in peritoneal dialysis(PD)patients.To explore the influencing factors of rapid peritoneal transport in PD patients.Methods:In this study,35 follow-up patients who underwent peritoneal equilibration test(PET)in the Peritoneal Dialysis Center of the Affiliated Hospital of Inner Mongolia Medical University from July 2022 to October 2022 were selected as the research objects.Peritoneal dialysis effluent(PDE)samples were collected during PET,and the level of AQP1 was detected by enzyme-linked immunosorbent assay(ELISA).Basic data,peritoneal dialysis data,laboratory indicators,and echocardiographic results of patients were recorded.the patients were grouped according peritoneal transport type and ultrafiltration volume.Statistical analysis was performed using SPSS 26.0,and Graph Pad Prism 8.0 was used for plotting.Results:(1)A total of 35 patients were included,including 19 males(54.3%)and 16 females(45.7%),with an average age of 52.14±13.86 years old,14.00(5.40,36.30)months of peritoneal dialysis,and an average BMI of 22.36±3.10 kg/m2.The primary disease was chronic glomerulonephritis in 12 patients(34.3%),hypertensive nephropathy in 9 patients(25.7%),diabetic nephropathy in 4 patients(11.4%),and other causes in 10 patients(28.6%).The ultrafiltration volume of all patients was 300(100,500)ml,and the 4-hour dialysis creatinine to blood creatinine ratio(4h D/PCr)was 0.63±0.09.According to the types of peritoneal transport,there were 22 cases of low-low-average transport(62.9%)and 13 cases of high-high-average transport(37.1%).16 patients(45.7%)received 2.5% glucose dialysate.(2)According to the types of peritoneal transport,all patients were divided into low-low-average transport group(L+LA)and high-high-average transport group(H+HA).There were statistically significant differences in age and primary diseases between L+LA group and H+HA group(P < 0.05),and the age of H+HA group was significantly higher than that of L+LA group.In comparison of primary diseases,chronic glomerulonephritis accounted for the highest proportion in L+LA group,and diabetic nephropathy accounted for the highest proportion in H+HA group.There were no significant differences in gender and BMI between the two groups(P > 0.05).Ultrafiltration and 4h ultrafiltration volume in L+LA group were higher than those in H+HA group,and the differences between the two groups were statistically significant(P < 0.05).The anterior and posterior diameter of left atrium in L+LA group was smaller than that in H+HA group,and the difference between the two groups was statistically significant(P < 0.05).Serum albumin and blood calcium in L+LA group were higher than those in H+HA group,and the difference between the two groups was statistically significant(P < 0.05).(3)There was a statistically significant difference in the level of AQP1 in PDE between L+LA group and H+HA group(t=4.372,P < 0.05).The level of AQP1 in PDE in L+LA group was significantly higher than that in H+HA group.(4)According to the median ultrafiltration volume of 300 ml,all enrolled patients were divided into low ultrafiltration group(<300ml)and high ultrafiltration group(≥300ml).Compared with the low ultrafiltration group,the level of AQP1 in the high ultrafiltration group was higher,and the difference between the two groups was statistically significant(t= 3.287,P <0.05).(5)Correlation analysis between AQP1 level in PDE and various indicators showed that the AQP1 level in PDE of peritoneal dialysis patients was positively correlated with ultrafiltration volume(r=0.617,P<0.001),4h ultrafiltration volume(r=0.376,P=0.026)and dialysis age(r=0.337,P=0.047).There was a negative correlation with 4h D/PCr(r=-0.633,P <0.001).(6)The ROC curve was plotted using the AQP1 level in PET according to the type of peritoneal transport in two groups,L+LA and H+HA,and the area under the curve(AUC)was 0.872(95% CI=0.74-1.00,P<0.05),with a maximum youden index of 0.647.When AQP1 level was higher than 2.025ng/ml,the sensitivity and specificity of being diagnosed with peritoneal low-low-average transport were 95.5% and 69.2%,respectively.(7)Single factor correlation analysis showed 4h D/PCr and ultrafiltration(r=-0.515,P<0.05),4h ultrafiltration(r=-0.380,P<0.05),serum albumin(r=-0.432,P<0.05),uric acid(r=-0.36,P<0.05)and AQP1 level(r=-0.633,P < 0.001)were negatively correlated.It was positively correlated with age(r=0.354,P<0.05).(8)Binary logistic regression analysis showed that age(OR=1.123,95%CI(1.007～1.252),P<0.05)and AQP1 level in PDE had significant influence on rapid peritoneal transport in peritoneal dialysis patients(OR=0.016,95%CI(0.001～0.458),P=0.016).Conculsions:1.AQP1 level of peritoneal dialysis effluent was positively correlated with the ultrafiltration and dialysis age,and negatively correlated with 4h D/PCr.AQP1 level is an independent protective factor for rapid peritoneal transport,and has a certain accuracy in determining the type of peritoneal transport,and is a potential noninvasive biological marker for evaluating the function of peritoneal transport.2.Age,serum albumin,uric acid and AQP1 level in PET are correlated with peritoneal transport characteristics in peritoneal dialysis patients.Age and AQP1 level in PDE have significant effects on the increase of peritoneal transport rate,and age is an independent risk factor for rapid peritoneal transport.