Do traditional symptoms of hypothyroidism correlate with biochemical disease?

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.

Cross-sectional study.

Seventy-six newly diagnosed case patients with overt hypothyroidism and 147 matched control patients identified through outpatient laboratories in Michigan and Colorado.

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).

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.