Correlation Between Serum Carnosinase-1 And Skin Advanced Glycation End Products And Diabetic Microvascular Complications In Patients With Type 2 Diabetes

Objective1.To explore the difference of serum carnosinase-1(CN-1)and skin advanced glycation end products(AGEs)between type 2 diabetes(T2DM)patients with and without microvascular complications.2.To explore the influencing factors of skin AGEs and serum CN-1 in patients with T2 DM.3.To explore the relationship between skin AGEs and serum CN-1 in patients with T2 DM.Methods1.134 patients with type 2 diabetes who were admitted to the Department of Endocrinology,the First Affiliated Hospital of Anhui Medical University from September 2016 to September 2017 were selected.The general indicators such as age,sex,height and weight of the subjects were collected,and the biochemical indicators such as fasting C-peptide,Hb A1 c,24h urine protein,and ratio of Urine Albumin to Creatinine(ACR)were detected.2.The patient was assessed for the presence or absence of diabetic nephropathy according to three independent measurements of ACR;the patient was assessed for the presence or absence of diabetic retinopathy based on the results of the sacral fundus imaging.3.Serum CN-1 concentration was measured by enzyme-linked immunosorbent assay(ELISA),and skin AGEs were measured by skin AGEs fluorescence spectrometer.4.To analyze the differences of skin AGEs and serum CN-1 between T2 DM patients with complications such as DR and DN and T2 DM patients without associated complications,the influencing factors of skin AGEs and serum CN-1,and the relationship between them relationship.Results1.There were no significant differences in gender,age,duration,body weight,BMI,blood pressure,Hb A1 c,fasting C-peptide,Scr,e GFR,24 h urine protein between the DR group and the NDR group(P>0.05).The skin AGEs and ACR were significantly higher than those in the NDR group,and the difference was statistically significant(P<0.05).2.There were no significant differences in gender,age,disease duration,body weight,BMI,blood pressure,Hb A1 c,fasting C-peptide,Scr,CN-1 between the DN group and the NDN group(P>0.05).The e GFR in the DN group was significantly lower than that in the NDN group.The ACR,24 h urine protein and skin AGEs were significantly higher than those in the NDN group(P<0.05).3.Multivariate analysis showed that gender,DR,and serum CN-1 concentrations were factors influencing skin AGEs.Compared with women,male patients had higher skin AGE,and the difference was statistically significant(P <0.01).There was a positive correlation between age and skin AGEs(r2=0.15,P<0.0001).4.Serum CN-1 was stratified into 4 quartiles,and there was a significant difference in skin AGE levels between the four serum CN-1 quartiles(P < 0.05).There was a negative correlation between skin AGEs and serum CN-1 concentration(r2=0.05,P<0.05).5.ACR <30 mg/g group,30 ?ACR <300 mg/g group and ACR?300 mg/g group have significant difference in skin AGEs.Patients with ACR <30 mg/g skin AGEs are significantly lower than 30 ?ACR < The AGEs of the skin in the 300 mg/g group and the ACR?300 mg/g group were significantly higher than those in the other two groups(P<0.05).There was no significant difference in serum CN-1 concentration between the three groups(P>0.05).Conclusions1.Skin AGEs in patients with type 2 diabetes may be involved in the pathogenesis of diabetic nephropathy and diabetic retinopathy,and can be used as an indicator to predict the occurrence and severity of complications in T2 DM patients.2.Serum CN-1 concentration is negatively correlated with skin AGEs,and the specific mechanism needs further investigation.