Incidence of subclinical thyroid dysfunction in Beijing population by physical check-ups

Abstract

Objective To understand the incidence of subclinical thyroid dysfunction in adult population of Beijing.Methods Serum levels of thyroid-stimulating hormone(TSH),T3,T4 and thyroid peroxidase antibody(TPOAb)were measured for 1966 persons living in Beijing by physical examinations in 2002,and 1646 of them(83.72%)were followed-up in 2004.Results Overall incidence of subclinical hypothyroidism and subclinical hyperthyroidism were 1.72 percent and 0.25 percent,respectively.Incidence of subclinical hypothyroidism in females aged ＞40 years was significantly higher than that in those ≤40 years(χ2=10.869,P＜0.01),but no significant difference between those ＞40 and ≤40 years in males was found.Incidence of subclinical hypothyroidism in females was significantly higher than that in males ＞40 years of age(χ2=24.122,P＜0.01),but no significant difference between females and males ≤40 years was found.No significant difference in incidence of subclinical hypothyroidism was noticed between varied age groups and between males and females.Incidence of subclinical hypothyroidism was significantly higher in those with history of subclinical hypothyroidism than that in those without it(χ2= 6.898,P＜0.01).No significant difference in incidence of subclinical hypothyroidism between those with family history of thyroid disease and those without it was found.Incidence of subclinical hypothyroidism was significantly higher in those with positive TPOAb than that in those with negative one(χ2=14.084,P＜0.01),but no significant difference in incidence of subclinical hyperthyroidism between those with positive and negative TPOAb was found.Conclusion Incidence of subclinical hypothyroidism was a little bit higher in population of Beijing area by physical examinations,particularly in females,elder age and positive TPOAb. Key words: Thyroid diseases; Incidence; Cross-sectional studies; Questionnaire