Relationship Of Metabolic Syndrome And Its Components With Thyroid Nodule(s)

Objective:To investigate the association between metabolic syndrome (MS), body mass index (BMI), hyperglycemia, dyslipidemia, hypertension and thyroid nodule(s) or thyroid functions in euthyroid subjects. Screen for the risk factors that affect the incidence of thyroid nodule(s).Method:419cases who received routain physical and laboratory examinations in the Health Management Centre of QianFoShan Hospital from Jun.2013to Dec.2013were enrolled in this retrospective study. All these subjects have complete clinical data. Their laboratory examinations, the ultrasonographic characteristics of their thyroid and other examinations were analyzed to explore their relationship with the incidence of thyroid nodule(s).Results:(1) A total of419cases were enrolled in this study, including288men and131women. Thyroid nodule(s) were found in217subjects and the total prevalence was51.79%. The prevalence of thyroid nodule(s) was significantly higher in female than in male (66.41%vs.45.14%, P<0.001), even in the same subgroup of age (40-49years,50-59years,≥60years). In addition, the prevalence of thyroid nodule(s) increased with age.(2) The prevalence of MS was higher in male (29.9%) than in female (6.1%) and the difference was statistically significant (P<0.001). The prevalence of thyroid nodule(s) was significantly higher in MS (+) group than MS (-) group (P=0.016<0.05).(3) Subjects were grouped according to gender and the existence of thyroid nodule(s). In male, patients who have thyroid nodule(s) have higher systolic blood pressure (SBP), diastolic blood pressure (DBP) and fasting plasma glucose (FPG). And the SBP and DBP have statistical difference (P<0.05). In female, patients with thyroid nodule(s) have higher level of SBP, DBP, FPG, triglycerol (TG) and lower level of high density lipoprotein-cholesterol (HDL-C), and the SBP, DBP, TG and HDL-C have statistical difference (P<0.05).(4) Multifactor logistic regression analysis showed that gender, age and DBP were independently correlated with the incidence of thyroid nodule(s)(gender:β=-1.115, OR=0.328, P<0.05; age:β=0.042, OR=1.043, P<0.05; DBP:β=0.019, OR=1.020, P<0.05). Moreover, higher FPG has relationship with the incidence of thyroid nodule(s)(OR=1.191). Subjects were subgrouped according to gender, blood pressure and FPG. Chi-square test showed that the prevalence of thyroid nodule(s) was higher both in the high-blood pressure group (62.80%vs.44.71%, P<0.001) and high-FPG group (63.53%vs.48.80%, P<0.05).(5) The relationship between MS and thyroid function was shown by multiple linear regression analysis. It showed that BMI has linear regression relationship with free triiodothyronine (FT3)(F=20.740, P=0.000). Analysis in subgroups found that free triiodothyronine (FT3) and free thyroxine (FT4) were significantly higher in the high-BMI group than the normal-BMI group (P<0.001, P=0.015<0.05). In addition, there were more subjects with thyroid stimulating hormone (TSH)>2.0ulU/ml in obesity-group than overweight-group (49.30%vs.41.12%).(6) Subjects were divided into different groups by the level of serum TSH. In the group with TSH<4.0uIU/ml, there was no significant differences between multiple comparison (P>0.05). The prevalence of thyroid nodule(s) was significantly higher in the group of TSH>4.0ulU/ml than TSH<4.0ulU/ml (77.78%vs.51.22%, OR=3.33). Multiple linear regression analysis showed that gender and TSH values have linear regression relation which can influence the level of TSH (r=0.212, P<0.05).Conclusions:(1) The prevalence of thyroid nodule(s) is high in euthyroid subjects. Female and elderly has significant higher prevalence than male and young people.(2) The prevalence of thyroid nodule(s) is significantly more frequent in MS(+) group than in MS(-) group. (3) Female, elderly and high blood pressure are the independent risk factor of the incidence of thyroid nodule(s). High-FPG is another risk factor for development of thyroid nodule(s).(4) Higher BMI may potential related to the changes of thyroid function.(5) Higher TSH level is a risk factor for thyroid nodule(s), and gender is related to the level of TSH.