Abstract
BACKGROUND: Few studies have scrutinized the spectrum of symptoms in subclinical hypothyroidism.
METHODS: From 3 Danish Investigation on Iodine Intake and Thyroid Diseases (DanThyr) cross-sectional surveys performed in the period 1997 to 2005, a total of 8903 subjects participated in a comprehensive investigation including blood samples and questionnaires on previous diseases, smoking habits, alcohol intake, and education. From the 3 surveys we included patients with subclinical hypothyroidism (n = 376) and euthyroid controls (n = 7619). We explored to what extent patients with subclinical hypothyroidism reported 13 previously identified hypothyroidism-associated symptoms (tiredness, dry skin, mood lability, constipation, palpitations, restlessness, shortness of breath, wheezing, globus 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, interquartile range), 2 (0-4) vs 2 (0-4), P = .25] compared with euthyroid controls. Within the group of subclinical hypothyroid patients, comorbidity had the highest impact on symptoms (tiredness, shortness of breath, wheezing; all P < .001); TSH level had no impact on symptom score; and younger age was accompanied by higher mental burden (tiredness, P < .001; mood lability, P < .001; restlessness, P = .012), whereas shortness of breath was associated with high body mass index (P < .001) and smoking (P = .007).
CONCLUSION: Patients with a thyroid function test suggesting subclinical hypothyroidism do not experience thyroid disease-related symptoms more often than euthyroid subjects. In subclinical hypothyroidism, clinicians should focus on concomitant diseases rather than expecting symptomatic relief following levothyroxine substitution.
| Originalsprog | Engelsk |
|---|---|
| Tidsskrift | American Journal of Medicine |
| Vol/bind | 134 |
| Udgave nummer | 9 |
| Sider (fra-til) | 1115-1126.e1 |
| ISSN | 0002-9343 |
| DOI | |
| Status | Udgivet - sep. 2021 |
Bibliografisk note
Funding Information:Funding: The present study is based on previous cross-sectional studies (C1+C2) and a register study of hypothyroid patients. Funding has been acknowledged in several papers. For the present study we were supported by the Beckett Foundation.
Funding Information:
We are indebted to the general practitioners in Copenhagen and Northern Jutland, and to clinical chemical laboratories at Aalborg Hospital, Bispebjerg Hospital, and Frederiksberg Hospital, as well as the Laboratory of General Practitioners in Copenhagen for their helpful collaboration in identifying patients. Funding: The present study is based on previous cross-sectional studies (C1+C2) and a register study of hypothyroid patients. Funding has been acknowledged in several papers. For the present study we were supported by the Beckett Foundation.
Publisher Copyright:
© 2021 Elsevier Inc.