Endocrine Abstracts

Background: Levothyroxine (LT4) is considered the standard of care for hypothyroidism, however 5-10% of hypothyroid individuals complain of persistent symptoms despite achieving biochemical euthyroidism on LT4.

Methods: 17,247 thyroid specialists from 28 countries were invited to participate in a survey. It enquired about respondents’ perceptions of the cause of hypothyroid-like persistent symptoms and how the prevalence of such complaints had changed over time. Geographic regions were defined according to the UN Statistics Division. Gross national income (GNI) information stems from https://data.worldbank.org/.

Findings: The response rate was 32.9%. Persistent symptoms despite normal TSH while receiving LT4 treatment was reported to affect up to 10.0% of patients by 75.4% of respondents. Main assumed causes for symptom persistence included psychosocial factors (77.1%), comorbidities (69.2%), and unrealistic patient expectations (61.0%). Multivariate analysis showed that the prevalence of persistent symptoms in Eastern Europe (OR 0.44; 95% CI 0.37-0.52), Southern Europe (OR 0.49; 95% CI 0.41-0.59), and Western Asia (OR 0.74; 95% CI 0.57-0.96) was lower than Western and Northern Europe. A lower frequency of persistent symptoms was also associated with longer respondent clinical experience (OR 0.40; 95% CI 0.30-0.52). In contrast, being an endocrinologist (OR 1•93; 95% CI 1.51-2.48), working at a university center (OR 1.26; 95% CI 1.11-1.42) and having a high-volume practice (OR 1.26; 95% CI 1.10-1.44) were associated with higher estimates of prevalence of persistent symptoms. Most respondents perceived either a stable or increasing trend (40.9% and 28.4%, respectively). Multivariate analysis showed that compared to Western Europeans, Northern Europeans and Western Asian respondents reported an increasing, while Eastern Europeans reported a decreasing trend. An increasing trend was also reported by respondents with a private practice and those with a high-volume practice.

Interpretation: The majority of THESIS respondents attributed the persistence of hypothyroid-like symptoms to psychosocial factors. It could be postulated that the higher prevalence of persistent symptoms reported by the specialists in endocrinology who work in academic and tertiary level structures is possibly due to referral of unresolved clinical conditions to these structures. The prevalence of dissatisfaction in hypothyroid patients seems to be rather stable over time. However, the prevalence of dissatisfied patients is increasing in countries with higher GNI, like the northern region of Europe, while is reported as decreasing in regions with lower GNI, like the eastern area of Europe.