Research of the prevalence of primary hypothyroidism in 721 cases of middle and old-aged people

Objective To determine the current prevalence of hypothyroidism in elderly and middle-aged people and to evaluate the morphology of thyroid.Methods 721 cases,aged 40 to 79,were enrolled in this study.Fasting venous blood were collected for detecting serum thyroid stimulating hormone(TSH),free thyroxine(FT4),thyroid peroxidase antibody(A-TPO) and thyroglobulin antibody(A-TG) with electrochemiluminescence assay.Thyroid in every case was screened by high sensitivity ultrasound.Results Seventeen cases with primary clinical hypothyroidism and 64 cases with primary subclinical hypothyroidism were found in all objects.The ratio of old group vs.middle-aged group was 1.27∶1 in prevalence of clinical hypothyroidism and 2.26∶1 in prevalence of primary subclinical hypothyroidism.The prevalence of subclinical hypothyroidism was 14.77% in old women,which was significantly higher than that in middle-aged women(P0.05).The overall prevalence rate of subclinical hypothyroidism was 11.50% in old people,which was significantly higher than that in middle-aged people(P0.05).The prevalence rate of thyroid antibody-positive in patients with hypothyroidism was higher than that of other people.The prevalence rate of thyroid nodule was 88.24% and 82.81% in clinical hypothyroidism patients and subclinical hypothyroidism patients,respectively.Conclusions Old people have a higher prevalence of primary hypothyroidism than middle-aged people.Patients with hypothyroidism tend to be thyroid antibody positive and to suffer from thyroid nodules easily.Screening of hypothyroidism and thyroid nodules should be strengthened in old people.