Risk for progression to overt hypothyroidism in an elderly Japanese population with subclinical hypothyroidism.
نویسندگان
چکیده
BACKGROUND Few population-based studies report the changes with time in thyroid function tests in patients with subclinical hypothyroidism. We compared the risk for developing overt hypothyroidism in patients with subclinical hypothyroidism and euthyroid controls from the same population of elderly Japanese. We also sought associations of selected parameters with the development of overt hypothyroidism in the subclinical hypothyroid and euthyroid groups. METHODS We measured thyrotropin (TSH) and free thyroxine (T4) levels at baseline examinations performed from 2000 to 2003 in the cohort of Japanese atomic-bomb survivors and identified 71 patients with spontaneous subclinical hypothyroidism (normal free T4 and TSH >4.5 mIU/L without a history of thyroid treatment, mean age 70 year) and 562 euthyroid controls. We re-examined TSH and free T4 levels an average of 4.2 years later (range, 1.9-6.9). RESULTS The risk for progression to overt hypothyroidism was significantly increased in subclinical hypothyroid patients (7.0%) compared with control subjects (1.6%) after adjusting for age and sex (odds ratio, 4.56; p=0.009). Higher baseline TSH levels were associated with progression from subclinical to overt hypothyroidism (p=0.02) in the multivariate analysis, including age, sex, antithyroid peroxidase antibody, and ultrasonography (US) findings. The analysis using binary TSH data suggested that a TSH level >8 mIU/L was a predictive value for development of overt hypothyroidism (p=0.005). On the other hand, serum TSH levels spontaneously normalized in 38 (53.5%) of the patients with subclinical hypothyroidism. In the multivariate analysis, normalization of TSH levels was associated with lower baseline TSH levels (p=0.004) and normal and homogenous thyroid US findings (p=0.04). Atomic-bomb radiation dose was not associated with subclinical hypothyroidism or its course. CONCLUSIONS Subclinical hypothyroidism was four times more likely to be associated with development of overt hypothyroidism than euthyroid controls in the sample population of Japanese elderly. TSH levels in half of the patients normalized spontaneously when assessed after an average follow-up period of 4.2 years. Baseline TSH level and thyroid US findings are potential predictors of future thyroid function in subclinical hypothyroidism.
منابع مشابه
Hypothyroidism in the elderly: diagnosis and management
Thyroid disorders are highly prevalent, occurring most frequently in aging women. Thyroid-associated symptoms are very similar to symptoms of the aging process; thus, improved methods for diagnosing overt and subclinical hypothyroidism in elderly people are crucial. Thyrotropin measurement is considered to be the main test for detecting hypothyroidism. Combined evaluations of thyroid stimulatin...
متن کاملLetter: The Biochemical Prognostic Factors of Subclinical Hypothyroidism (Endocrinol Metab 2014;29:154-62, Myung Won Lee et al.)
Subclinical hypothyroidism is defined as a serum thyroid stimulating hormone (TSH) concentration above the upper limit of its reference range plus a serum free thyroxine (FT4) concentration within its reference range. There are several controversies regarding the effect of subclinical hypothyroidism on the risk of heart failure, cardiovascular disease risk, cholesterol metabolism and mortality,...
متن کاملThe Prevalence of Thyroid Disorders in Pregnant Women of Hamadan
Introduction: Different studies have demonstrated that maternal thyroid dysfunction during pregnancy is associated with adverse obstetrics and fetal outcomes. There is no international consensus regarding to use a guidelines for screening in high risk women. The aim of the present study was to determine prevalence of thyroid disorders in high and low risk pregnant women. Methods: In a cross-se...
متن کاملThe Prevalence of Hypothyroidism Based on Risk Factors in Pregnant Women Referred to Shahid Dadbin Clinic, Kerman, Iran
Background & Aims: Since at early pregnancy (<20 week) fetal thyroid gland is undeveloped, normal development of the Fetal brain is highly dependent on maternal thyroid hormones. There are excessive adverse perinatal outcomes associated with overt and subclinical hypothyroidism such as increase of Abortion, preeclampsia, placenta Abruption, LBW, preterm labor, impaired fetal neuropsychological ...
متن کاملNatural history of subclinical hypothyroidism in children and adolescents
Diagnosis of subclinical hypothyroidism (SH) is based on interpretation of biochemical tests in the absence of the evident clinical symptoms. Mildly elevated TSH with normal fT4 are common in adults and the prevalence of this finding is reported to be 1-10% of general population, being higher in the elderly. In pediatric population its prevalence is lower than 2%. Moreover in about 60% of subje...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Thyroid : official journal of the American Thyroid Association
دوره 21 11 شماره
صفحات -
تاریخ انتشار 2011