Background: The associations between thyroid cancer and skeletal outcomes have not been thoroughly investigated. We aimed to investigate the risk of osteoporotic fractures in patients with thyroid cancer compared to that in a matched control group. Methods: This retrospective cohort study included 2,514 patients with thyroid cancer and 75,420 matched controls from the Korean National Health Insurance Service-National Sample Cohort (NHIS-NSC, 2006–2019). The rates of osteoporotic fractures were analyzed, and associations with the levothyroxine dose were evaluated. Results: Patients with thyroid cancer had a significantly lower risk of fracture than did the control group (hazard ratio [HR], 0.81; 95% confidence interval [CI], 0.69 to 0.94; P=0.006). Patients diagnosed with thyroid cancer after the age of 50 years (older cancer group) had a significantly lower risk of fracture than did those in the control group (HR, 0.72; 95% CI, 0.6 to 0.85; P<0.001), especially those diagnosed with spinal fractures (HR, 0.66; 95% CI, 0.51 to 0.85; P=0.001). Patients in the older cancer group started osteoporosis treatment earlier than did those in the control group (65.5±7.5 years vs. 67.3±7.6 years, P<0.001). Additionally, a lower dose of levothyroxine was associated with a reduced risk of fractures. Conclusion In the clinical setting, the risk of fracture in women diagnosed with thyroid cancer after the age of 50 years was lower than that in the control group, which was caused by more proactive osteoporosis treatment in postmenopausal women with thyroid cancer.

Background: The associations between thyroid cancer and skeletal outcomes have not been thoroughly investigated. We aimed to investigate the risk of osteoporotic fractures in patients with thyroid cancer compared to that in a matched control group. Methods: This retrospective cohort study included 2,514 patients with thyroid cancer and 75,420 matched controls from the Korean National Health Insurance Service-National Sample Cohort (NHIS-NSC, 2006–2019). The rates of osteoporotic fractures were analyzed, and associations with the levothyroxine dose were evaluated. Results: Patients with thyroid cancer had a significantly lower risk of fracture than did the control group (hazard ratio [HR], 0.81; 95% confidence interval [CI], 0.69 to 0.94; P=0.006). Patients diagnosed with thyroid cancer after the age of 50 years (older cancer group) had a significantly lower risk of fracture than did those in the control group (HR, 0.72; 95% CI, 0.6 to 0.85; P<0.001), especially those diagnosed with spinal fractures (HR, 0.66; 95% CI, 0.51 to 0.85; P=0.001). Patients in the older cancer group started osteoporosis treatment earlier than did those in the control group (65.5±7.5 years vs. 67.3±7.6 years, P<0.001). Additionally, a lower dose of levothyroxine was associated with a reduced risk of fractures. Conclusion In the clinical setting, the risk of fracture in women diagnosed with thyroid cancer after the age of 50 years was lower than that in the control group, which was caused by more proactive osteoporosis treatment in postmenopausal women with thyroid cancer.

Background: The associations between thyroid cancer and skeletal outcomes have not been thoroughly investigated. We aimed to investigate the risk of osteoporotic fractures in patients with thyroid cancer compared to that in a matched control group. Methods: This retrospective cohort study included 2,514 patients with thyroid cancer and 75,420 matched controls from the Korean National Health Insurance Service-National Sample Cohort (NHIS-NSC, 2006–2019). The rates of osteoporotic fractures were analyzed, and associations with the levothyroxine dose were evaluated. Results: Patients with thyroid cancer had a significantly lower risk of fracture than did the control group (hazard ratio [HR], 0.81; 95% confidence interval [CI], 0.69 to 0.94; P=0.006). Patients diagnosed with thyroid cancer after the age of 50 years (older cancer group) had a significantly lower risk of fracture than did those in the control group (HR, 0.72; 95% CI, 0.6 to 0.85; P<0.001), especially those diagnosed with spinal fractures (HR, 0.66; 95% CI, 0.51 to 0.85; P=0.001). Patients in the older cancer group started osteoporosis treatment earlier than did those in the control group (65.5±7.5 years vs. 67.3±7.6 years, P<0.001). Additionally, a lower dose of levothyroxine was associated with a reduced risk of fractures. Conclusion In the clinical setting, the risk of fracture in women diagnosed with thyroid cancer after the age of 50 years was lower than that in the control group, which was caused by more proactive osteoporosis treatment in postmenopausal women with thyroid cancer.

Background: The associations between thyroid cancer and skeletal outcomes have not been thoroughly investigated. We aimed to investigate the risk of osteoporotic fractures in patients with thyroid cancer compared to that in a matched control group. Methods: This retrospective cohort study included 2,514 patients with thyroid cancer and 75,420 matched controls from the Korean National Health Insurance Service-National Sample Cohort (NHIS-NSC, 2006–2019). The rates of osteoporotic fractures were analyzed, and associations with the levothyroxine dose were evaluated. Results: Patients with thyroid cancer had a significantly lower risk of fracture than did the control group (hazard ratio [HR], 0.81; 95% confidence interval [CI], 0.69 to 0.94; P=0.006). Patients diagnosed with thyroid cancer after the age of 50 years (older cancer group) had a significantly lower risk of fracture than did those in the control group (HR, 0.72; 95% CI, 0.6 to 0.85; P<0.001), especially those diagnosed with spinal fractures (HR, 0.66; 95% CI, 0.51 to 0.85; P=0.001). Patients in the older cancer group started osteoporosis treatment earlier than did those in the control group (65.5±7.5 years vs. 67.3±7.6 years, P<0.001). Additionally, a lower dose of levothyroxine was associated with a reduced risk of fractures. Conclusion In the clinical setting, the risk of fracture in women diagnosed with thyroid cancer after the age of 50 years was lower than that in the control group, which was caused by more proactive osteoporosis treatment in postmenopausal women with thyroid cancer.

Purpose: Current clinical practices favor less or no thyroid-stimulating hormone (TSH) suppression for low- to intermediate-risk thyroid cancer patients who receive thyroid lobectomy. The association of TSH suppression on healthrelated quality of life (HR-QoL) in patients after thyroid lobectomy is not well studied. This study aimed to evaluate the effect of TSH suppression on patient HR-QoL after thyroid lobectomy. Methods: This study included patients enrolled in an ongoing, multicenter, randomized controlled study investigating the effects of TSH suppression. Patients were randomized to either the low-TSH group (TSH target range, 0.3–1.99 μIU/ mL) or the high-TSH group (TSH target range, 2.0–7.99 μIU/mL). The HR-QoL, hyperthyroidism symptom, and depression symptom questionnaires performed preoperatively and 2 weeks and 3 months postoperatively were evaluated. Results: Total of 669 patients (low-TSH group, 340; high-TSH group, 329) were included. Although total HR-QoL score changes were not different between the 2 groups, the high-TSH group had a significantly higher score in the physical domain at postoperative 3 months (P = 0.046). The 2 groups did not have significant differences in hyperthyroidism and depression scores. Conclusion In the short-term postoperative period, the physical HR-QoL scores in thyroid lobectomy patients were better when they did not receive TSH suppression. This study suggests the importance of considering HR-QoL when setting TSH suppression targets in thyroid lobectomy patients.

Background: The severity of coronavirus disease 2019 (COVID-19) among patients with long-term glucocorticoid treatment (LTGT) has not been established. We aimed to evaluate the association between LTGT and COVID-19 prognosis. Methods: A Korean nationwide cohort database of COVID-19 patients between January 2019 and September 2021 was used. LTGT was defined as exposure to at least 150 mg of prednisolone (≥5 mg/day and ≥30 days) or equivalent glucocorticoids 180 days before COVID-19 infection. The outcome measurements were mortality, hospitalization, intensive care unit (ICU) admission, length of stay, and mechanical ventilation. Results: Among confirmed patients with COVID-19, the LTGT group (n=12,794) was older and had a higher proportion of comorbidities than the control (n=359,013). The LTGT group showed higher in-hospital, 30-day, and 90-day mortality rates than the control (14.0% vs. 2.3%, 5.9% vs. 1.1%, and 9.9% vs. 1.8%, respectively; all P<0.001). Except for the hospitalization rate, the length of stay, ICU admission, and mechanical ventilation proportions were significantly higher in the LTGT group than in the control (all P<0.001). Overall mortality was higher in the LTGT group than in the control group, and the significance remained in the fully adjusted model (odds ratio [OR], 5.75; 95% confidence interval [CI], 5.31 to 6.23) (adjusted OR, 1.82; 95% CI, 1.67 to 2.00). The LTGT group showed a higher mortality rate than the control within the same comorbidity score category. Conclusion Long-term exposure to glucocorticoids increased the mortality and severity of COVID-19. Prevention and early proactive measures are inevitable in the high-risk LTGT group with many comorbidities.

Subclinical hypothyroidism (SCH) is characterized by elevated thyroid-stimulating hormone (TSH) and normal free thyroxine levels. The Korean Thyroid Association recently issued a guideline for managing SCH, which emphasizes Korean-specific TSH diagnostic criteria and highlights the health benefits of levothyroxine (LT4) treatment. A serum TSH level of 6.8 mIU/L is presented as the reference value for diagnosing SCH. SCH can be classified as mild (TSH 6.8 to 10.0 mIU/L) or severe (TSH >10.0 mIU/L), and patients can be categorized as adults (age <70 years) or elderly (age ≥70 years), depending on the health effects of LT4 treatment. An initial increase in serum TSH levels should be reassessed with a subsequent measurement, including a thyroid peroxidase antibody test, preferably 2 to 3 months after the initial assessment. While LT4 treatment is not generally recommended for mild SCH in adults, it is necessary for severe SCH in patients with underlying coronary artery disease or heart failure and it may be considered for those with concurrent dyslipidemia. Conversely, LT4 treatment is generally not recommended for elderly patients, regardless of SCH severity. For those SCH patients who are prescribed LT4 treatment, the dosage should be personalized, and serum TSH levels should be regularly monitored to maintain the optimal LT4 regimen.

Background: This study investigated the incidence of endocrine immune-related adverse events (irAEs) for recently developed immune checkpoint inhibitor (ICI) drugs. Methods: We collected studies on newly developed ICI drugs using PubMed/Medline, Embase, and Cochrane Library from inception through January 31, 2023. Among ICI drugs, nivolumab, pembrolizumab, and ipilimumab were excluded from the new ICI drugs because many papers on endocrine-related side effects have already been published. Results: A total of 44,595 patients from 177 studies were included in this analysis. The incidence of hypothyroidism was 10.1% (95% confidence interval [CI], 8.9% to 11.4%), thyrotoxicosis was 4.6% (95% CI, 3.8% to 5.7%), hypophysitis was 0.8% (95% CI, 0.5% to 1.1%), adrenal insufficiency was 0.9% (95% CI, 0.7% to 1.1%), and hyperglycemia was 2.3% (95% CI, 1.6% to 3.4%). Hypothyroidism and thyrotoxicosis occurred most frequently with programmed cell death protein-1 (PD-1) inhibitors (13.7% and 7.5%, respectively). The rate of endocrine side effects for the combination of a programmed death-ligand 1 inhibitor (durvalumab) and cytotoxic T lymphocyte-associated antigen 4 inhibitor (tremelimumab) was higher than that of monotherapy. In a meta-analysis, the combination of tremelimumab and durvalumab had a 9- to 10-fold higher risk of pituitary and adrenal-related side effects than durvalumab alone. Conclusion Newly developed PD-1 inhibitors had a high incidence of thyroid-related irAEs, and combined treatment with durvalumab and tremelimumab increased the risk of pituitary- and adrenal-related irAEs. Based on these facts, it is necessary to predict the endocrine side effects corresponding to each ICI drug, diagnose and treat them appropriately, and try to reduce the morbidity and mortality of patients.

Subclinical hypothyroidism (SCH), characterized by elevated serum thyroid-stimulating hormone (TSH) levels and normal free thyroxine levels, usually presents without symptoms, and is often discovered incidentally during routine blood test. The Task Force of the Korean Thyroid Association Committee of Clinical Practice Guidelines has established a guideline to evaluate and manage SCH; the guideline emphasizes the implementation of diagnostic criteria based on the TSH reference range for Koreans and focuses on the proven health benefits of levothyroxine (LT4) treatment. Based on the Korea National Health and Nutrition Examination Survey (2013-2015), serum TSH level of 6.8 mIU/L is considered the reference value for SCH. SCH can be categorized as mild (TSH 6.8-10.0 mIU/L) or severe (TSH ＞10.0 mIU/L), and patients are classified as adults (age ＜70 years) or elderly patients (age ≥70years) depending on the health effects of LT4 treatment. An initial increase in serum TSH levels should be reassessed with a subsequent measurement, along with the thyroid peroxidase antibody test, preferably 2-3 months after the initial evaluation. Usually, LT4 treatment is not recommended for mild SCH in adults; however, treatment is necessary for severe SCH in patients with underlying coronary artery disease or heart failure and can be considered for coexisting dyslipidemia. LT4 treatment is not recommended for mild or even severe SCH in elderly patients, in general. Patients with SCH who receive LT4 treatment, the LT4 dosage should be personalized, and serum TSH levels should be monitored to ensure optimal LT4 dosage (dosage that is neither excessive nor insufficient). Patients with SCH who do not receive LT4 treatment require periodic follow-up at appropriate testing intervals determined by disease severity. The guideline also provides several educational points applicable in clinical settings.