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Biomedical subjects

G J Canaris

Publications and source records attributed to G J Canaris.

2 recordsLinked to original sources

The Colorado thyroid disease prevalence study.

CONTEXT: The prevalence of abnormal thyroid function in the United States and the significance of thyroid dysfunction remain controversial. Systemic effects of abnormal thyroid function have not been fully delineated, particularly in cases of mild thyroid failure. Also, the relationship between traditional hypothyroid symptoms and biochemical thyroid function is unclear. OBJECTIVE: To determine the prevalence of abnormal thyroid function and the relationship between (1) abnormal thyroid function and lipid levels and (2) abnormal thyroid function and symptoms using modern and sensitive thyroid tests. DESIGN: Cross-sectional study. PARTICIPANTS: Participants in a statewide health fair in Colorado, 1995 (N = 25 862). MAIN OUTCOME MEASURES: Serum thyrotropin (thyroid-stimulating hormone [TSH]) and total thyroxine (T4) concentrations, serum lipid levels, and responses to a hypothyroid symptoms questionnaire. RESULTS: The prevalence of elevated TSH levels (normal range, 0.3-5.1 mIU/L) in this population was 9.5%, and the prevalence of decreased TSH levels was 2.2%. Forty percent of patients taking thyroid medications had abnormal TSH levels. Lipid levels increased in a graded fashion as thyroid function declined. Also, the mean total cholesterol and low-density lipoprotein cholesterol levels of subjects with TSH values between 5.1 and 10 mIU/L were significantly greater than the corresponding mean lipid levels in euthyroid subjects. Symptoms were reported more often in hypothyroid vs euthyroid individuals, but individual symptom sensitivities were low. CONCLUSIONS: The prevalence of abnormal biochemical thyroid function reported here is substantial and confirms previous reports in smaller populations. Among patients taking thyroid medication, only 60% were within the normal range of TSH. Modest elevations of TSH corresponded to changes in lipid levels that may affect cardiovascular health. Individual symptoms were not very sensitive, but patients who report multiple thyroid symptoms warrant serum thyroid testing. These results confirm that thyroid dysfunction is common, may often go undetected, and may be associated with adverse health outcomes that can be avoided by serum TSH measurement.

Adult↗

Do traditional symptoms of hypothyroidism correlate with biochemical disease?

OBJECTIVE: Hypothyroidism often remains undetected because of the difficulty associating symptoms with disease. To determine the relation between symptoms and biochemical disease, we assessed symptoms and serum thyroid function tests, concurrently, for patients with and without hypothyroidism. DESIGN: Cross-sectional study. SETTING/PATIENTS: Seventy-six newly diagnosed case patients with overt hypothyroidism and 147 matched control patients identified through outpatient laboratories in Michigan and Colorado. MEASUREMENTS AND MAIN RESULTS: Patient symptoms were assessed by questionnaire. Case patients reported a higher proportion of hypothyroid symptoms than did control patients (30.2% vs 16.5%, p < .0001). Univariate analysis identified three significant predictors of an elevated level of thyroid-stimulating hormone (TSH) (p < .05), and 13 symptoms which, when they had changed in the past year, were reported more often by case patients with hypothyroidism than by control patients (p < .005). Individuals reporting changes in 7 or more symptoms were significantly more likely to have hypothyroidism (likelihood ratio [LR] = 8.7, 95% confidence interval [CI] 3.8, 20.2); those reporting changes in 2 or fewer symptoms were less likely to have hypothyroidism (LR = 0.5, 95% CI 0.4, 0.7). CONCLUSIONS: In this sample, the number of hypothyroid symptoms reported was directly related to the level of TSH. The association was stronger when more symptoms were reported. Symptoms that had changed in the past year were more powerful than symptoms reported present at the time of testing. This suggests that traditional symptoms are valuable when deciding which patients to test for hypothyroidism.

Adult↗