ABSTRACT
Objective To investigate the value of chloride clearance test in differential diagnosis of Gitelman syndrome (GS). Methods For patients with hypokalemic metabolic alkalosis and highly suspected GS,clinical data were documented and SLC12A3 gene screening was performed as gold standard to diagnose GS. Hydrochlorothiazide (HCT) test and furosemide (FUR) test were performed according to the standard process. Baseline and maximal increasement of chloride excretion fraction (FECl,the net and relative increase measured as εFECl) were compared between patients and controls to evaluated the reaction to the corresponding diuretics. Receiver operating characteristic (ROC) curve was used to evaluate the sensitivity and specificity of HCT test in GS diagnosis. Results Totally 27 patients and 20 health controls received HCT test. Among those patients,23 were diagnosed with GS genetically. When using the net and relative εFECl to diagnose GS,the areas under the ROC curve were 0.987 (95% CI:0.963～1.000,P<0.001) and 0.984 (95%CI:0.950～1.000,P<0.001),respectively. When a reasonable cutoff value for εFECl was selected,the sensitivity and specificity were both higher than 95%. Eight patients received both HCT test and FUR test. Five of them showed decreased reaction to HCT(net εFECl≤2.86% or relative εFECl≤223%),while normal reaction to FUR.SLC12A3 mutations confirmed their GS. Three patients with blunt reaction to FUR showed normal reaction to HCT,finally they were diagnosed as BS clinically because no SLC12A3 gene mutation was detected. Conclusion Comprehensive application of HCT test and FUR test to evaluate the diuretic reaction can effectively differentiate GS and BS.
Subject(s)
Humans , Case-Control Studies , Chlorides , Metabolism , Diagnosis, Differential , Gitelman Syndrome , Diagnosis , Hydrochlorothiazide , Kinetics , Mutation , ROC Curve , Sensitivity and Specificity , Solute Carrier Family 12, Member 3 , Genetics , MetabolismABSTRACT
<p><b>OBJECTIVE</b>To observe the features of lipid metabolism disorders of peritoneal dialysis(PD)patients and hemodialysis(HD)patients and explore the association of lipid metabolism disorder with peritoneum transport ability and mortality.</p><p><b>METHODS</b>The clinical data of 127 PD patients and 95 HD patients who had received regular dialysis for more than 3 months in Peking Union Medical College Hospital since March 2009 were retrospectively analyzed.Serum lipid profiles were tested.Serum hypersensitive C reactive protein(hsCRP)was examined by immune turbidimetric method.Serum carbohydrate antigen 125(CA125)and iPTH were detected by electrochemical luminescence method.Peritoneum transport ability was evaluated through peritoneal equilibration test(PET).After a 2-year follow-up,the levels of CA125 and the peritoneum transport abilities were compared between the baseline data and the end point,and the relationship between lipid disorder and the mortality was analyzed.</p><p><b>RESULTS</b>After the 2-year follow-up,25(19.7%)PD patients died.The leading cause of death was congestive heart failure(56.0%),followed by myocardial infarction(12.0%),septic shock(12.0%),respiratory failure(8.0%),asphyxiation(8.0%),and gastrointestinal bleeding(4.0%).Compared with the survivors,the death patients were older(P=0.005),with significant lower albumin level(P=0.000)and pre-albumin level(P=0.001).However,there was no significant difference in other clinical features including body mass index(BMI),blood pressure,dialysis time,nPCR,iPTH,hemoglobin,hsCRP,and serum lipid level(all P>0.05).COX regression analysis showed that diabetes mellitus(P=0.030)and mean SBP(P=0.048)were significantly associated with the mortality of PD patients.At the baseline,the CA125 level in patients with high,high average,and low average transport status of peritoneum was(38.02±64.37),(21.21±19.41),and(17.55±23.2)U/ml,respectively(P=0.09).There was no association between the transport status and lipid(TC,TG and LDL).</p><p><b>CONCLUSIONS</b>Congestive heart failure is the leading cause of death among PD patients.Diabetes and blood pressure are the dependent risk factors of mortality.Lipid disorder is associated with CA125,while its association with peritoneum transport ability or mortality was not found.</p>