An Epidemiological Study Of The Relationship Between Thyroid Dysfunction And Metabolic Syndrome In Adults

Objective To estimate the prevalence of thyroid dysfunction among the staff of a Petrochemical Corporation in Ningbo. Methods A population survey was conducted.10461 workers (including retired workers) were enrolled. Their medical history were investigated by questionairys,and blood samples were collected for thyroid function detection. Results In this petrochemical employees cohort, the prevalences of thyroid dysfunctions were 4.62%,2.70% and 9.11% in total population, male and female, repectively, while the standardized rates were 2.95%,2.06% and 5.31%, accordingly. The prevalence of diagnosed thyroid diseases was 1.81%,0.86% in male and 4.09% in female. Twenty-five percent of individuals with thyroid surgery or medications had abnormal thyroid function. The prevalence of unrecognized thyroid dysfunctions was 2.87%,1.88% in male and 5.29% in female. Subclinical hypothyroidism accounted for 81.7% of unrecognized thyroid dysfunctions.The prevalence of subclincical hypothyroidism was higher in aged people over 70 yrs than in other ages. Conclusions The prevalence of thyroid dysfunctions was over 4.5% in all workers of a Petrochemical Corporation in Ningbo. Subclinical hypothyroidism was the most popular form in all kinds of unrecognized thyroid functional disorders. The prevalence of subclinical hypothyroidism increased with age and was higher in female than in male.Objective To estimate the prevalence of thyroid dysfunctions among the retired staff of a Petrochemical Corporation in Ningbo. Methods A population survey was conducted.1759 retired workers over age 60 years were investigated to participate in a health survey with a questionnaire, and blood samples were collected for thyroid function detection. Results In this elderly cohort, the prevalence of diagnosed thyroid diseases was 3.9%,7.6% in female and 1.9% in male. The prevalence of unrecognized thyroid dysfunctions was 4.7%,6.9% in female and 3.5% in male. The prevalence of total thyroid dysfunctions was 8.5%,14.0% in female and 5.4% in male. Subclinical hypothyroidism accounted for 81.0% of unrecognized thyroid dysfunctions. The prevalence of thyroid dysfunction was higher in elderly people than in non-elderly persons.Conclusions The prevalence of thyroid dysfunctions was over 10% in the elderly retired workers of a Petrochemical Corporation in Ningbo. Subclinical hypothyroidism was the most popular form in all kinds of unrecognized thyroid functional disorders. The prevalence of subclinical hypothyroidism was higher in females than in males.Objective To explore the prevalence of metabolic syndrome in an occupational population.Methods The data of totally 10461 employees aged 20-90 collected from a Petrochemical Corporation in Ningbo were analyzed. The prevalence of metabolic syndrome was calculated using the criteria of IDF definition pulished in 2005. Results①The prevalence of central overweight, blood pressure over 130/85 mmHg or hypertension, impaired fasting glucose or diabetes mellitus, low HDL-C, high TG and metabolic syndrome were 21.2%,43.5%,11.1%,12.1%,27.1% and 10.2%.②The standardized prevalence of metabolic syndrome was 5.8%. The prevalence of metabolic syndrome was 10.1% in male and 10.5% in female, while the standardized rates were 5.9% and 5.7%, accordingly.③The prevalence of these diseases were increased with aging, and compared with the people yonger than 40 years old, the prevalence of hyperglucemia, hyertention and metabolic syndrome were 2-9 times higher in the people older than 40. Conclusion High prevalence of metabolic syndrome and its related diseases among the employees were observed in the Petrochemical Corporation in Ningbo. Objective To study the relationship between the prevalence of thyroid dysfunction and components of metabolic syndrome in Ningbo. Methods A total of 10461 workers aged 20 to 90 years of a Petrochemical Corporation in Ningbo were included. Body mass index (BMI), waist circumference, blood pressure, fasting plasma glucose and lipid profile concentrations were measured in all subjects. Metabolic syndrome was diagnosed according to the International Diabetes Federation (IDF) criteria. Results①The prevalences of metabolic syndrome and overall thyroid dysfunction were 10.2% and 4.6%, respectively.②About one fifth of petrochemical employees had abdominal obesity with at least one component of metabolic syndrome.③There was no significant difference in the prevalence of metabolic syndrome within lowered TSH, normal TSH and elevated TSH groups.④Logistic regression analyses revealed that low HDL-C was associated with lowered TSH (OR=2.808,95%CI:1.632-4.833), and high TG was associated with elevated TSH (OR=1.483,95%CI:1.128-1.950).⑤There were significant correlations between serum TSH levels and lipid parameters such as TC in males, TG and LDL-C in females, and HDL-C in both gender. Conclusion The prevalence of thyroid dysfunction was not associated with central obesity, hypertension and hyperglycemia. Lipid disorder was correlation with serum TSH levels.Objective To study the relationship between the prevalence of hyperuicemia and thyroid dysfunction. Methods 10461 active and retired workers aged 20 to 90 years of a Petrochemical Corporation in Ningbo were included. Serum thyroid-stimulatin hormone (TSH), free thyroxine (FT4), free triiodothyronine (FT3) and serum uric acid (SUA) were measured. Results①The prevalence of hyperuricemia was 18.9% in total workers,23.6% in males and 7.7% in females, respectively.②The prevalence of former diagnosed thyroid diseases was 1.8% in total,0.8% in males and 4.1% in females, respectively.③In 10272 individuals without a history of thyroid disease, the prevalence of thyroid dysfunction was 2.9% in total,1.9%in males and 5.3% in females, respectively. The percentage of subjects with a low TSH concentration was 0.3% in males and 0.8% in females; the percentage of subjects with an elevated TSH concentration was 1.6% in males and 4.5% in females.④Compared with normal TSH workers, the serum uric acid was significantly increased in subjects with either high TSH or low TSH (P<0.001) in females.⑤Logistic regression analysis revealed that low TSH was an independent factor associated with hyperuricemia (OR=1.93 for males and 1.97 for females, P all<0.001, respectively). Conclusion The prevalence of hyperuricemia was independently associated with increased TSH concentration. Overt or subclinical hypothyroidism may be risk factors for hyperuricemia.Objective To study the effect of mild subclinical hypothyroidism on the endothelium-dependent relaxing function in middle-aged persons. Methods Seventy participants in middle-aged persons without cardiovascular disease and thyroid surgry history were included in this study. Thirty-five of them with normal thyroid function and the others with little-mild subclinical hypothyroidism (TSH 4.7-9.9 mU/L). Endothelial-dependent relaxing function was measured with high-resolution B-mode ultrasound in all participants. Results Flow-mediated dilatation was not significantly impaired in the group of mild subclinical hypothyroidism compared with matched controls with normal thyoid function (16.0%±4.5% vs 16.4%±6.7%, P>0.05). There were no significant difference in baseline (3.82±0.25 mm vs 3.83±0.25 mm) and the nitroglycerin-induced dilatation (17.8%±5.5% vs 17.3%±5.4%) in two groups. Conclusion Endothelium-dependent relaxing function was not impaired in middle-aged patients with mild subclinical hypothyroidism, and mild increased TSH levels may not as a direct risk factor of cardiovascular disease.