Abstract
In differentiated thyroid cancer (DTC), the standard treatment includes total thyroidectomy
and lifetime levothyroxine (LT4) replacement. However, long-term exogenous LT4 has
become controversial due to the adverse effects of oversuppression. The study included
191 patients (aged 18–76 years) with a prospective diagnosis of non-metastatic DTC
and 79 healthy individuals. The patients with DTC were stratified into three groups
according to their TSH levels: suppressed thyrotropin if TSH was below 0.1 μIU/ml,
mildly suppressed thyrotropin if TSH was between 0.11 and 0.49 μIU/ml, and low-normal
thyrotropin if THS was between 0.5 and 2 μIU/ml. The Beck Depression Inventory (BDI),
Beck Anxiety Inventory (BAI), Anxiety Sensitivity Index (ASI), Short Symptom Inventory
(SSI), and Pittsburgh Sleep Quality Index (PSQI) were administered to all participants.
It was found that the BDI, BAI, SSI and PSQI scores were worse in patients with DTC
(p=0.024, p=0.014, p=0.012, and p=0.001, respectively). According to theTSH levels,
the mean ASI was found to be higher in the suppressed and mildly suppressed thyrotropin
groups (19±14.4 vs. 10.6±11.1; 16.4±14.9 vs. 10.6±11.1, p=0.024, respectively), the
mean SSI was found higher in the suppressed group (61.0±55.5 vs. 35.1±37.0, p=0.046),
and the mean PSQI was higher in all three groups (7.94±3.97 vs. 5.35±4.13; 7.21±4.59
vs. 5.35±4.13; 7.13±4.62 vs. 5.35±4.13, p=0.006) when compared with the controls.
No significant difference was found between the groups. A positive correlation was
detected in the duration of LT4 use and BDI and SSI, and a weak, negative correlation
was detected between TSH levels and ASI and PSQI. Based on our study, it was found
that depression, anxiety disorders, and sleep problems were more prevalent in patients
with DTC, being more prominent in the suppressed TSH group. These results were inversely
correlated with TSH values and positively correlated with the duration of LT4 use.
Unnecessary LT4 oversuppression should be avoided in patients with DTC.
Key words differentiated thyroid cancer - levothyroxine - subclinical hyperthyroidism - thyroid-stimulating
hormone