Analysis Correlation Between Obesity Phenotypes And Thyroid Function In Middle-aged Patients

Objective:To explore the influences of different obesity phenotypes on thyroid hormones,we try to compare the levels of thyroid hormones and thyroid autoantibodies among the middle-aged obese patients who belong to different obesity phenotypes.Methods:1.201 middle-aged subjects with normal thyroid function in the Affiliated Hospital of North Sichuan Medical College in Nanchong from January 2021 to April 2021 were recruited,and divided into 76 cases of metabolically healthy normal weight(MHNW),39 cases of metabolically healthy obesity(MHO)and 86 cases of metabolically unhealthy obesity(MUO)according to metabolic factors and body mass index(BMI).2.The data of age,BMI,systolic blood pressure(SBP),diastolic blood pressure(DBP),fasting blood glucose(FBG),Glycated hemoglobin A1c(HbA1c),triglyceride(TG),total cholesterol(TC),high density lipoprotein cholesterol(HDL-C),thyroid peroxidase antibody(TPOAb),thyroid globulin antibody(TgAb),free triiodothyronine(FT3),free thyroxine(FT4)and thyroid stimulating hormone(TSH)of the subjects were collected.3.Upon the comparison of the general data and the levels of thyroid function and thyroid autoantibodies in the MHNW group,MHO group and MUO group,the correlation between BMI,thyroid function and other indicators were explored,the influences of different obesity phenotypes on thyroid hormones were analyzed.4.All data analysis relied on SPSS25.0 statistical software.Most data in this study did not obey normal distribution,the data were expressed by median(quartile)or example(%).The comparison of measurement data between groups was tested by Kruskal-Wallis test,multiple comparison was tested by Bonferroni test,and the chi-square test was used for the comparison of count data between groups.Correlation analysis was tested by spearman correlation,and the influences of different obesity phenotypes on thyroid hormones were analyzed by logistic regression analysis.Results:1.In MUO group,the incidence rate of one metabolism disorder,two metabolism disorders,three or more metabolism disorders were 58.14%,26.74%,and 15.12%respectively,hypertension was 69.77%,hyperlipidemia was 61.63%,hyperglycemia was 11.63%.2.BMI of MHO group and of MUO group were significantly higher than those of MHNW group,in which the difference was statistically significant(P<0.05).The levels of FBG,HbAlc,TG,SBP and DBP in MUO group were higher than those in MHNW group(P<0.05),and the levels of TG,SBP and DBP in MUO group were higher than those in MHO group(P<0.05).Compared with that of MHNW group,the level of HDL-C in MHO group and MUO group was decreased(P<0.05).As for other groups,the levels of FBG,HbA1c,TG,HDL-C,BMI,SBP,and DBP showed no significant statistical significance(P>0.05).Similarly,there were no significant differences in age,sex and the level of TC among the three groups(P>0.05).3.The level of FT3 in MUO group was significantly higher than that in MHNW group,in which the difference was statistically significant(P<0.01).The level of FT4 in MUO group was higher than that in MHO group(P<0.05).The TgAb(+)constituent ratio of MHNW group and MHO group were higher than that of MUO group(P<0.05).However,there was no significant difference in the level of TSH and the constituent ratio of TPOAb(+)among the three groups(P>0.05).4.Correlation analysis:①The level of BMI was positively correlated with the levels of SBP(r=0.512,P<0.001),DBP(r=0.468,P<0.001),FBG(r=0.319,P<0.001),HbA1c(r=0.234,P=0.001),TG(r=0.414,P<0.001)and FT3(r=0.193,P=0.006),and negatively correlated with the level of HDL-C(r=-0.408,P<0.001).②The level of FT3 was positively correlated with the levels of SBP(r=0.196,P=0.005),DBP(r=0.337,P<0.001),TG(r=0.177,P=0.012)and FT4(r=0.340,P<0.001),and negatively correlated with the level of HDL-C(r=-0.254,P<0.001).③The level of FT4 was positively correlated with the levels of DBP(r=0.202,P=0.004),TG(r=0.196,P=0.005)and TPOAb(r=0.213,P=0.002).④The level of TSH was negatively correlated with the level of FBG(r=-0.154,P=0.029).5.According to the levels of FT3 and FT4,the subjects were divided into lower group and higher group by P50(median)respectively,which were assigned as dependent variables(lower group=0,higher group=1).Meanwhile,different obesity phenotypes were taken as independent variables(MHNW group as control group),for logistic regression analysis.Results:After adjusting for age,sex,TPOAb and TgAb,there was no risk of increased FT4 among different obesity phenotypes with no risk of FT3 rising in the MHO group and elevated FT3 was found in the MUO group.Conclusion:1.MUO phenotype was mainly characterized by one metabolism disorder,and the most common metabolism disorder was hypertension.2.The levels of thyroid hormones were different in different obesity phenotypes.MUO phenotype tended to have higher FT3 level compared to MHNW phenotype.On the other hand,MHO and MUO phenotypes may have weak influence on FT4 and TSH.3.MUO phenotype was less likely to develop autoimmune thyroid disease.4.Early control of body weight and metabolism disorder to prevent the development of MHO phenotype to MUO phenotype may reduce active thyroid hormones.