Clinical Characteristics Of Insulin Resistance In Obese Children And Adolescents

ObjectiveTo study the clinical characteristics of physical growth and metabolic disorder in obese children and adolescents with insulin resistance(IR).Methods 1.Objective: Children and adolescents between 6-and 18-year old were selected to receive health examination or obesity treatment in the department of child health of Nanjing Children's Hospital from September 2015 to April 2018.According to the classification standard of overweight and obesity in Chinese school-age children and adolescents,they were divided into control group and obese group.2.Anthropometric measuring: The body composition of height,weight,body fat quality,body fat percentage(PBF)and skeletal muscle mass were determined by bioelectrical impedance analysis(BIA).The percentage of skeletal muscle(PBM),waist circumference,hip circumference,waist-to-hip ratio(WHtR)and waist-to-hip ratio(WHR)were calculated,as well as the BMI and BMI standard deviation score.And the pubertal stages were determined by Tanner score.3.Blood glucose,total cholesterol(TC),triglycerides(TG)and high-density lipoprotein(HDL-c)were measured by biochemical method.Alanine transaminase(ALT),aspartate transaminase(AST)and uric acid(UA)were quantified by colorimetry;25-(OH)-VD3 was measured by enzyme-linked immunoassay.Non-high-density lipoprotein cholesterol =TC-TG.The homeostasis model evaluation method of insulin resistance index(HOMA-IR)=[fasting blood glucose(mmol/L)*fasting blood insulin(FBI)(mU/L)] /22.5.The insulin resistance was considered as HOMA-IR greater than 2.8.4.Abdominal ultrasoud was made for the liver,gallbladder and adrenal gland.Carotid endometrium thickness,peak systolic velocity and end-diastolic blood flow velocity were examined by carotid b-ultrasonography.5.Statistical analysis: SPSS 22.0 software was used for data analysis.P<0.05 was concidered as statistically significant.Results 1.A total of 741 subjects were recruited in this study,including 348 males in the obesity group,aged 10.3±2.0 years and 145 males in the control group,age 10.5±2.4 years.There were 138 females in the obese group,aged 10.0± 2.2 years,and 120 females in the control group,aged 9.5±2.3.2.BMI(P<0.001),waist circumference(P<0.001),hip circumference(P<0.001),WHR(P<0.001)and WHtR(P<0.001)of the obese group were significantly higher than those of the control group.However,PBM was lower than that of the control group(P<0.001).The fasting insulin level of the obese group was significantly higher than that of control group(male: 12.82 vs 8.81mmol/L,P<0.001;female: 15.64 vs 9.06 mmol/L,P<0.001).The incidence of insulin resistance in the obese group(46.8% in males,55.8% in females)were significantly higher than that in the control group(13.1% in males,14.2% in females,P<0.001).3.Correlation analysis showed that HOMA-IR was positively correlated with age,BMI,waist circumference,hip circumference,WHtR,WHR and PBF(P<0.001)respectively;while it was significantly negative correlatied with PBM(P<0.001).Stepwise regression analysis showed that the waist circumference was significantly related to IR in both males and females(male: B =0.09,P<0.01,female: B =0.08,P<0.01).After puberty initiation,HOMA-IR increased significantly boht in obesity and control group(P<0.05).What's more,the interaction between BMI and puberty increased significantly in obese group(P<0.05).4.There is no significant difference in birth weight and parents' BMI between the obese(244 cases)and obese with IR(242 cases)(P>0.05).However,waist circumference and hip circumference of the IR group were higher than that of the non-IR group(P<0.001).And the results remained significant after adjusting for age.But there was no significant difference in WHR,PBM and DBP(P>0.05).HOMA-IR combined with peak insulin levels after sugar load were used to determine whether IR or not.We find that waist circumference,hip circumference,WHtR,BMI-SDS and PBF in IR group were significantly higher than those in non-IR group(P<0.05).And the difference remained significant after adjusting for age(P< 0.05).5.Obesity with IR had higher SBP,ALT,UA,TG,FBG,FBI and 2-hour-postprandial blood insulin(2h-PBI)compared to the obese group with non-IR(P<0.005).What's more,obesity with IR had high percentage of glucose metoblism dysfunction,nonalcoholic fatty liver disease(NAFLD),high TG,high non-HDL-c,high UA and liver function impirement than non-IR group(P<0.05).6.Obese children with hyperinsulinemia were added to the IR group.The waist circumference,hip circumference,WHtR,BMI-SDS and PBF were significantly higher than those in the non-IR group(P<0.05).Moreover,the number of obese children with abnormal glucose metabolism,NAFLD,high TG,high non-HDL-c,impaired liver function and metabolic syndrome was higher than that of obese children with HOMA-IR>2.8(P<0.05).Conclusion Childhood and adolescent obesity increases the occurrence of insulin resistance.Waist circumference is significantly correlated with HOMA-IR,which is an important indicator to predict obesity combined with insulin resistance.The risk of abnormal glucose metabolism,abnormal lipid metabolism,NAFLD and high UA were significantly increased in children and adolescents with IR.It indicated that besides blood glucose,we should moniter the alternation in ALT,TG and UA;and decrease the obesity-related metabolic disorders,thus to prevent IR.