Prevalence and influencing factors of thyroid diseases among adults in Liaoning province: a community based survey

  Objective  To examine the prevalence and influencing factors of thyroid disease among adult residents in Liaoning province.

  Methods  Using age and sex stratified cluster sampling, we surveyed 2 931 residents aged 18 – 85 years and living in local regions at least 5 years in 2 villages and 2 communities from coastal Yingkou city and inland Shenyang city. Questionnaire interview, thyroid ultrasound examination, detections of serum iodine (SI), urine iodine (UI), iodine in table salt, thyroid function and antibodies, thyroid-stimulating hormone (TSH), free thyroxine (fT4), free triiodothyronine (fT3), thyroid peroxidase antibody (TPOAb), and thyroglobulin antibody (TgAb) were conducted among the participants from 2017 through 2018. Iodine nutrition, prevalence of thyroid diseases and its influencing factors among the participants were analyzed.

  Results  For all the participants, the median of UI and SI were 167.6 µg/L and 62.1 µg/L, indicat-ing an appropriate overall iodine level; the proportions of the participants with lower (40 < µg /L) and higher (90 > µg /L) SI were 4.3% (n = 125) and 6.4% (n = 186). The overall detection rate of thyroid diseases was 37.15%, and the detection rates were 20.37% for thyroid nodules, 16.17% for autoimmune thyroiditis (AITD), 1.91% for endemic goiter, 1.43% for hypothyroidism, 5.53% for subclinical hypothyroidism, 0.92% for hyperthyroidism, and 0.61% for subclinical hyperthyroidism, respectively. The detection rate of hypothyroidism, hyperthyroidism, AITD, goiter and all thyroid diseases differed significantly among the participants with different SI (P < 0.05 for all). The results of multivariate logistic regression analysis revealed following risk factors for thyroid disease: female gender (odds ratio OR = 2.03), family history of thyroid disease (OR = 1.65), advanced age (OR = 1.33), and overweight or obesity (OR = 1.60); the results also indicated that SI, intake of iodine-rich foods and income were significant influencing factors of thyroid disease.

  Conclusion  The prevalence of thyroid disease is at a moderate level and closely influenced by gender, age, family history of thyroid disease, and body mass index among adult residents in Liaoning province. The results suggest that women and middle-aged/elderly people are key populations in thyroid disease prevention and treatment.