Evaluation of thyroid diseases and metabolic factors in district of Yiğilca in Duzce province

Introduction: The most common disease of the thyroid gland is thyroid gland nodules and it is also seen commonly in our country. Metabolic Syndrome (MS) is a cluster of risk factors related with increased risk for cardiovascular diseases including premature atherosclerosis, impaired glucose metabolism, diabetes mellitus (DM), abdominal obesity, essential hypertension, dyslipidemia and with proinflammatory and prothrombotic components. Both pathologies (nodular goiter and MS) are quite frequent in the adult populations of industrialized countries and studies showed that some constitutive traits of MS could influence thyroid size and the occurence of thyroid nodules in the absence of clinical or subclinical thyroid dysfunction and this may occur independently of the effects of thyroid hormones. And also studies showed that the relationship between the both pathology could be related with insulin effect, so thyroid gland could be another victim of the insulin resistance syndrome. In this study, our aim is to evaluate the relationship between the thyroid nodularity and metabolic syndrome.Material - Method: The MELEN Study is a prospectively designed survey on the prevalence of cardio metabolic risk factors in 2298 Turkish adults with a mean age of 50. The baseline visits were carried out in May and June, 2010 and biennial follow-up visits were planned. Datas were collected by questionnaires, pysical examination and measurements, doppler ultrasound examination of carotid intima media thickness, echocardiographic examination, ECG recording, bioempedance meter analysis of body composition, thyroid ultrasonography and various biochemical analysis. The final study cohort was included 2233 participants (1430 women, 803 men).Results: In our study, 30.5% of the participants had goiter and also 80% of them were euthyroid. Thyroid nodule (MNG ve NG) detection rate was very high with 58.4%. In participants with goiter, rates of ultrasonographic thyroid disease, TSH abnormalities and comorbidities were found to be significantly higher. The relationship between metabolic parameters and the increase in nodularity was almost independent of TSH value in the assessments of euthyroid sub-group. In the presence of MS, the presence of goiter and MNG rate (61.5%) were detected as significantly higher. In MS group, BMI, mean thyroid volume, HOMA-IR values were significantly higher and there was no meaningful effect of IR on the mean thyroid volume and thyroid nodularity. In logistic regression analysis, when age, gender, active smoking, alcohol use and the presence of MS evaluated, the only factor affecting the presence of NG was found to be as age, but in the presence of MNG, age, parity, and the presence of MS were found to be associated with. So the presence of MS suggested to be associated with the presence of MNG rather than NG. When the relationship between the presence of MNG and MS components were assessed only significant effect of systolic blood pressure elevation was detected but there was not any effect of IR, waist circumference, and lipid parameters.Conclusion: As a result, MS, regardless of TSH values, have effects on thyroid cell growth. Although the main pathway for this interaction was thought to be the effect of insulin and also has been shown in some studies, in our study there was no significant correlation between insulin resistance and thyroid nodularity. When the results are evaluated, the presence of MNG is seen to be closely associated with age, systolic blood pressure, increase in number of births and the presence of MS. In conclusion, especially in MS patients, screening of the thyroid diseases may be useful in early diagnosis of thyroid diseases.Key words: Metabolic syndrome, nodular guatr, insulin resistance