Subclinical hypothyroidism in a biethnic, urban community

OBJECTIVES: To evaluate the association between hypothyroidism, and the hea lth status of older Hispanic and non-Hispanic white (NHW) men and women. To accomplish this, we determined the prevalences of the treated and untreate d conditions and examined the associations between an elevated serum thyroi d stimulating hormone (TSH) and cognitive and affective (mood) functions an d the prevalences of symptoms and comorbidity, specifically coronary heart disease (CHD), diabetes, hypertension, and hyperlipidemia. DESIGN AND SETTING: A cross-sectional study of equal numbers of Hispanic an d NHW men and women selected randomly from the Health Care Financing Admini stration (Medicare) rolls and recruited for a home interview followed by a 4-hour interview/examination in a senior health clinic. PARTICIPANTS: 883 volunteers, mean age 74.1 years, participated in intervie ws/examinations MEASUREMENTS: Serum TSH was determined in 825 participants responding to qu estions about thyroid replacement therapy. Serum free thyroxine (free T-4) concentrations were determined in 139 participants with elevated TSH concen trations (>4.6 mu U/mL). Symptoms, cognitive tests, a screen for depression , comorbidities (e.g., CHD), and risk factors (e.g., lipid abnormalities, d iabetes, and hypertension) were compared in participants with high versus n ormal TSH values. RESULTS: Subclinical hypothyroidism is more common in women than in men and in non-Hispanic white women compared with Hispanic women. No differences w ere observed between participants with TSH elevations from 4.7 to 10 mu U/m L and those with normal TSH concentrations, and only a few differences were observed in those with TSH concentrations above 10. CONCLUSIONS: Subclinical hypothyroidism is a common condition in community- living older people, especially women. However, it appeared to have no effe ct on any of the measures of health status utilized until serum TSH concent rations exceeded 10 mu U/mL, and even then the effects were rarely signific ant.