Investigation On Selenium Levels In Community Patients With Type 2 Diabetes Mellitus And Its Influence Factors

ObjectivesThe present study aimed at understanding the status of selenium levels in patients with type 2 diabetes mellitus(T2DM)through measuring selenium levels in Suzhou community patients with T2DM and comparing with healthy residents enrolled as controls.Meanwhile,the main influence factors of selenium levels were analyzed to provide appropriate reference for the epidemiological study of T2DM and the dietary guidance for patients based on selenium levels.MethodsThis was a cross-sectional survey study and the convenient sampling method was applied.The community T2DM patients(case group)who met the criterias of both inclusion and exclusion,and the age-and sex-matched healthy residents(control group)were also recruited from Dec.2017 to Dec.2018.The general information questionnaire was used to collect general demographic and clinical data of the two groups.The subjects'fasting venous blood samples were collected in the morning to measure(1)Selenium Levels:selenoprotein P(SelP),glutathione peroxidase(GPx3),and serum selenium;(2)Biochemical Parameters:1)glycometabolism:fasting plasma glucose(FPG)and hemoglobin Ale(HbAlc);2)lipid metabolism:total cholesterol(TC),triglycerides(TG),high-density lipoprotein(HDL),and low-density lipoprotein(LDL);3)liver function:alanine aminotransferase(ALT),aspartate aminotransferase(AST),total protein(TP),albumin(ALB),total bilirubin(TBIL),and alkaline phosphatase(ALP);4)kidney function:urea nitrogen(BUN),creatinine(CREA),and uric acid(UA).The hair samples were taken to measure selenium content in the hair at the same time.ResultsA total of 336 subjects,including 176 T2DM patients and 160 healthy residents were finally recruited.1.Comparisons of selenium levels between T2DM patients and healthy residents(1)SelP concentration:The SelP concentration was substantially higher in T2DM patients compared to healthy controls with either unadjusted BMI(1816.4± 488.2 vs.1681.7 ± 468.4 ng/mL)or adjusted BMI(1811.1 ± 36.3 vs.1688.2± 40.5 ng/mL),respectively(P<0.05).(2)GPx3 activity:There was no significant difference of GPx3 activity in T2DM patients compared to healthy subjects with either unadjusted BMI(229.1±29.4 vs.231.9 ±30.6 U/mL)or adjusted BMI(230.1± 2.2 vs.230.8 ± 2.3 U/mL),respectively(P>0.05).(3)Serum selenium level:The serum selenium level was substantially higher in T2DM patients compared to healthy controls(105.2 ± 58.1 vs.94.7± 59.1 ?g/L)(P<0.01).(4)Hair selenium level:There was no significant difference of hair selenium level between T2DM patients and healthy residents(372.9± 99.4 vs.358.8±99.8 ?g/kg)(P>0.05).2.Analysis of influence factors affecting subjects' selenium levels(1)SelP concentration:The binary logistic regression was performed with serum SelP as a dependent variable.The results showed that:1)ALP[?=-1.373;95%CI(0.087-0.736);P=0.012],systolic blood pressure[?=-0.047;95%CI(0.930-0.978);P<0.001],duration of T2DM[?=-0.074;95%CI(0.877-0.983);P=0.011],and with or without clinical complications[?=1.237;95%CI(1.465-8.109);P=0.005]were influence factors of serum SelP in patients with T2DM.2)Length of residence in Suzhou[?=-0.919;95%CI(1.004-1.033);P=0.021]was the influence factor of serum SelP in healthy residents.3)Payment manner of medical expenses[?=0.786;95%CI(1.084-4.448);P=0.029]was the influence factor of serum SelP in total subjects.(2)GPx3 activity:The multiple linear regression analysis was performed with GPx3 as a dependent variable.The results showed that:1)CREA(?=-0.378;P<0.001),UA(?=-0.069;P=0.009),BMI(?=-2.177;P=0.002),systolic blood pressure(?=-0.275;P=0.031),and payment manner of medical expenses(?=29.160;P<0.001)were influence factors of GPx3 in patients with T2DM.2)UA(?=-0.088;P=0.008),TP(?=-0.804;P=0.034),and marital status(? 13,160;P=0.017)were influence factors of GPx3 in healthy residents.3)UA(?=-0.062;P=0.009),BMI(?=-2.001;P<0.001),and CREA(?=-0.290;P=0.004)were influence factors of GPx3 in total subjects.(3)Serum selenium level:The binary logistic regression was performed with serum selenium as a dependent variable.The results showed that:1)ALB[?=-1.391;95%CI(0.065-0.959);P=0.043]and CREA[?=-1.482;95%CI(0.072-0.718);P=0.012]were influence factors of serum selenium in patients with T2DM.2)ALP[?=-1.915;95%CI(0.038-0.568);P=0.005],UA[?=-1.272;95%CI(0.099-0.789);P=0.016],systolic blood pressure[?=0.025;95%CI(1.002-1.049);P=0.033],and whether drinking or not[?=1.896;95%CI(1.182-37.497);P=0.032]were influence factors of serum selenium in healthy residents.3)With or without T2DM[?=-0.799;95%CI(0.267-0.757);P=0.003],CREA[?=-0.982;95%CI(0.142-0.985);P=0.047],and UA[?=-0.973;95%CI(0.184-0.774);P=0.008]were influence factors of serum selenium in total subjects.(4)Hair selenium level:The binary logistic regression was performed with hair selenium as a dependent variable.The results showed that:1)whether smoking or not[?=-1.151;95%CI(0.133-0.755);P=0.010],whether drinking or not[?=1.366;95%CI(1.191-12.909);P=0.025],and whether perming/dyeing or not[?=-1.113;95%CI(0.124-0.867);P=0.025]were influence factors of hair selenium in T2DM patients.2)HDL[?=-1.276;95%CI(0.083-0.936);P=0.039]and whether perming/dyeing or not[?=-1.554;95%CI(0.079-0.565);P=0.002]were influence factors of hair selenium in healthy residents.3)ALB[?=-1.410;95%CI(0.095-0.626);P=0.003]and whether perming/dyeing or not[?=-1.300;95%CI(0.137-0.542);P<0.001]were influence factors of hair selenium in total subjects.Conclusions1.The serum SelP concentration and serum selenium level in community patients with T2DM are significantly higher than those in healthy residents,while no significant differences of GPx3 activity and hair selenium level are observed between the two groups of subjects.2.In summary,the liver and kidney function parameters are the main influence factors of selenium levels in subjects.With impairment in the liver or kidney,the expressions of serum SelP,GPx3,serum selenium,and hair selenium in vivo would be reduced.