Metabonomics Of Insulin Resistance In Patients With Chronic Kidney Disease

Backround and objective:Chronic kidney disease(CKD)progression to end stage renal disease(ESRD)has become an important public health challenge in the world.Recent studies have shown that insulin resistance(IR)often occurs in patients with CKD.Both of them cause a vicious cycle of cause and effect,leading to the progression of kidney disease and metabolic disorders.IR,as an independent risk factor for non-diabetic CKD patients,is closely related to nutritional imbalance,cardiovascular events,etc.Although the main cause of IR is related to obesity,However,IR can also occur in CKD patients with normal or even low body weight.As an intervention risk factor,to study the IR of CKD patients,to identify the relevant risk factors and targeted intervention,it may be possible to improve the prognosis of patients with CKD and ESRD.At present,there is still a lack of correlation analysis and mechanism study of non-obese CKD patients with IR.This study established the HOMA-IR homeostasis model to assess IR status and explore the occurrence of IR in CKD patients,especially non-obese CKD patients.Analyze the influencing factors,and then use metabonomics to study the blood metabolism of ESRD patients without obesity with IR Products,and ELISA validation,screening for IR-related metabolites in patients with CKD,to further explore the mechanism of insulin resistance in patients with CKD.Methods:(1)According to the inclusion and exclusion criteria,CKD patients who visited the Department of Nephrology at the PLA General Hospital from January 2016 to November 2017 were retrospectively analyzed.The patients were calculated based on the clinical indicators such as height,weight,fasting insulin,serum creatinine,and blood urea nitrogen.Body mass index(BMI)is defined as obesity with a BMI>28 kg/m2.The CKD staging was performed according to the glomerular filtration rate(eGFR)level,and the HOMA homeostasis model was established to evaluate the IR status.The incidence of IR in non-obese CKD patients at each stage was compared,and the univariate correlation analysis was used.Multiple stepwise regression analysis was used to study IR related factors.(2)A total of 25 non-obese patients with ESRD who were admitted to PLA General Hospital Department of Nephrology from April 2016 to December 2016 were enrolled in the study.Three groups of control subjects,non-obese non-insulin-resistance ESRD patients,obese patients with insulin resistance,and healthy subjects were selected,with 25 patients in each group.100 cases of blood were detected by liquid chromatography-mass spectrometry(LC-MS).Partial least squares discriminant analysis(PLS-DA)and principal component analysis(PCA)were performed by metabolomics.),combined with statistical analysis,screening out potential differential metabolites.Different metabolites were searched for their functions and involved metabolic pathways through KEGG and HMDB databases to screen potential differential metabolites.A total of 18 ESRD patients with non-obese insulin resistance were enrolled in the PLA General Hospital Department of Nephrology from July 2017 to December 2017.Three groups of control subjects,non-obese non-insulin resistant ESRD patients,obese patients with insulin resistance,and healthy subjects were selected,with 18 patients in each group.According to the results of mass spectrometry and data analysis,potential differential metabolites screened out by enzyme linked immunosorbent assay(ELISA)were verified.Results:(1)In non-obese CKD patients,the incidence of IR increases gradually with the progressive deterioration of renal function.The incidence of IR in non-obese CKD patients was statistically significant(P=0.000).The univariate correlation analysis showed that the HOMA-IR index was positively correlated with urea nitrogen,triglyceride,parathyroid hormone,CKD stage,and negatively correlated with total protein,albumin,and high-density lipoprotein in non-obese CKD patients.Multiple regression analysis showed that the urea nitrogen,parathyroid hormone,and CKD stages of non-obese CKD patients entered the final regression equation,and HOMA-IR was positively correlated with urea nitrogen,parathyroid hormone,and CKD stage(P<0.05).(2)A total of 301 metabolites were produced in the positive ion mode and 417 metabolites in the negative ion mode using the liquid chromatography-mass spectrometry technique.Through PLS-DA analysis and PCA analysis combined with the rank sum test,a total of 80 metabolites in the positive and negative ion modes were screened,and differentially selected metabolites were searched through the KEGG and HMDB databases to identify 40 potentially related differential metabolites.It was found that it participates in important metabolic processes including glycolysis,gluconeogenesis,amino acid synthesis and metabolism,and fat metabolism,and it also participates in other metabolite processes such as vitamin metabolism and the AMPK signaling pathway process.Combined with the pathogenesis of CKD and IR,6 potentially significant biomarkers were screened,of which?-cryptoxanthin was significantly lower than the other three groups,AICAR,SAM,pantothenic acid,hippuric acid,4-HPPA.Significantly higher than the other three groups.The above blood metabolites were tested by ELISA.The results of ELISA showed that the level of ?-cryptoxanthin in ESRD with IR group was significantly lower than that in healthy group,obese with IR group and ESRD without IR group,P<0.05;ESRD The levels of blood AICAR,hippuric acid and 4-HPPA in IR group were significantly higher than those in healthy group,obese IR group and ESRD non-IR group,P<0.05;SAM,pantothenic acid levels in ESRD with IR group,and healthy group There was no significant difference between the obesity group with IR and the ESRD without IR group.Conclusions:(1)This study found that with non-obese CKD patients,with the progression of kidney disease,the incidence of IR gradually increased,elevated blood urea nitrogen,elevated parathyroid hormone,decreased renal function are related risk factors for non-obese CKD patients with IR.(2)In this study,liquid chromatography-mass spectrometry techniques were used to determine the ESRD-IR specific blood metabolite expression profile and participate in important metabolic processes including glycolysis,gluconeogenesis,amino acid synthesis and metabolism,and fat metabolism,and participate in other metabolisms.Physical processes,such as vitamin metabolism and AMPK signaling pathway processes,indicate that there are serious metabolic disorders in patients with ESRD and IR.Different potentially metabolites were screened out.Six potential biomarkers were tested by ELISA.Considering the decrease of blood ?-cryptoxanthin,the elevation of AICAR,hippuric acid,and 4-HPPA was helpful for CKD with IR.The auxiliary diagnosis can be used as potentially relevant differential metabolites.