Does subclinical hypothyroidism add on any symptoms? evidence from a Danish population-based study.

Abstract Background Few studies have scrutinized the spectrum of symptoms in subclinical hypothyroidism. Methods From three DanThyr cross-sectional surveys performed in the period 1997 to 2005, a total of 8,903 subjects participated in a comprehensive investigation including blood samples and questionnaires on previous diseases, smoking habits, alcohol intake, and education. From the three surveys we included patients with subclinical hypothyroidism (n=376) and euthyroid controls (n=7,619). We explored to which extent patients with subclinical hypothyroidism reported 13 previously identified hypothyroidism-associated symptoms (tiredness, dry skin, mood lability, constipation, palpitations, restlessness, shortness of breath, wheezing, globuluss sensation, difficulty swallowing, hair loss, dizziness/vertigo, and anterior neck pain). In various uni- and multivariate regression models we searched for circumstances predicting why some patients have more complaints than others. Results Subclinically hypothyroid patients did not report higher hypothyroidism score ((median, IQR), 2 (0-4) vs. 2 (0-4), p=0.25) compared to euthyroid controls. Within the group of subclinical hypothyroid patients: co-morbidity had the highest impact on symptoms (tiredness, shortness of breath, wheezing; all p Conclusion Patients with a thyroid function test suggesting subclinical hypothyroidism do not express thyroid disease related symptoms more often than euthyroid subjects. In subclinical hypothyroidism, clinicians should focus on concomitant diseases rather than expecting symptomatic relief following levo-thyroxine substitution.