The Association Between Subclinical Hypothyroidism And Carotid Intima-media Thickness

Objective: To investigate the association between Subclinical Hypothyroidism and Carotid Intima-Media Thickness.Methods: Between 2011 and 2012,10207 Chinese adults from general community aged 40 years or older were recruited in Dalian Centre,Liaoning province,China,as a part of the baseline survey of the REACTION study.10300 subjects were informed and10207 subjects signed informed consent and finished questionnaires.Thyroid function and carotid artery intima-media thickness were collected and 312 subclinical hypothyroidism(SCH) patients were recruited in this study for a period of three years of follow-up.253 participants completed the follow-up study,the follow-up rate was81.1%.Social demographic data,anthropometry,blood tests and ultrasound examination were collected before and after the follow-up study.Data were analyzed by SPSS19.0statistical software.Measurement data satisfied normal distribution were represented as x ±s,measurement data not satisfied normal distribution were represented as 25%-75%quatile,and enumeration data were represented as n(%).Correlation analysis were performed by Pearson or Spearman correlation analysis and multiple linear stepwise regression analysis.After 3 years’ follow-up,comparison between base-line data and follow-up data were performed by paired t-test and paired Wilcoxon test.P < 0.05 was defined as statistically significant.Results: 1.In the base-line data,312 SCH patients were included in The average age of them were 57.78 ± 8.38 years; 59 of them were smokers,accounted for 18.9%;HDL 1.46±0.33mmol/L; LDL 3.41±0.94mmol/L TC 5.61±1.09mmol/L; TG1.50±0.88mmol/L FT34.22±0.41pmol/l; FT4 12.39±1.48pmol/l TSH 7.34 ± 3.43 IU/ml;systolic blood pressure 142.79±23.41 mm Hg and diastolic blood pressure79.67±12.45 mm Hg; heart rate 79.61±11.89 /min; BMI 25.76±3.92 Kg/m2 and IMT1.00±0.16 mm.2.By using the Spearman correlation analysis,we found that age,smoking,HDL,LDL,TC,TG,FPG,FT3,TSH,systolicblood pressure,diastolic blood pressure were correlated with IMT(P<0.05).3.Multivariate linear stepwise regression analysis was used to explore the impact factors of IMT of SCH.The results showed that age,TSH,FPG,systolic blood pressure,LDL,CHOL and smoking were entered into the regression equation(P<0.05).TSH was related to IMT in the patients with subclinical hypothyroidism.4.Paired Wilcoxon test was used to analyse the difference of IMT of SCH after three years’ follow up.All objects were divided into two parts,TSH<10 IU/ml group,and TSH ≥ 10IU/ml group,the results were statistically significant in TSH ≥ 10IU/ml group,P<0.05.Conclusion:TSH level is an independent risk factor of IMT in patients with subclinical hypothyroidism.The level of IMT increased significant in TSH≥10μIU/ml subclinical hypothyroidism group after three years’ follow up.