Background: Coronavirus disease 2019 (COVID-19) can cause various extrapulmonary sequelae, including diabetes. However, it is unclear whether these effects persist 30 days after diagnosis. Hence, we investigated the incidence of newly diagnosed type 2 diabetes mellitus (T2DM) in the post-acute phase of COVID-19. Methods: This cohort study used data from the Health Insurance Review and Assessment Service, a representative national healthcare database in Korea. We established a cohort of 348,180 individuals diagnosed with COVID-19 without a history of diabetes between January 2020 and September 2021. The control group consisted of sex- and age-matched individuals with neither a history of diabetes nor COVID-19. We assessed the hazard ratios (HR) of newly diagnosed T2DM patients with COVID-19 compared to controls, adjusted for age, sex, and the presence of hypertension and dyslipidemia. Results: In the post-acute phase, patients with COVID-19 had an increased risk of newly diagnosed T2DM compared to those without COVID-19 (adjusted HR, 1.30; 95% confidence interval [CI], 1.27 to 1.33). The adjusted HRs of non-hospitalized, hospitalized, and intensive care unit-admitted patients were 1.14 (95% CI, 1.08 to 1.19), 1.34 (95% CI, 1.30 to 1.38), and 1.78 (95% CI, 1.59 to 1.99), respectively. The risk of T2DM in patients who were not administered glucocorticoids also increased (adjusted HR, 1.29; 95% CI, 1.25 to 1.32). Conclusion COVID-19 may increase the risk of developing T2DM beyond the acute period. The higher the severity of COVID-19 in the acute phase, the higher the risk of newly diagnosed T2DM. Therefore, T2DM should be included as a component of managing long-term COVID-19.

Background: The correlation between acute coronavirus disease 2019 (COVID-19) and subacute thyroiditis (SAT) has not been clearly investigated in “long COVID” patients. We aimed to investigate the incidence of SAT during convalescence and after the acute phase of COVID-19, comparing with that of the general population. Methods: Data from a total of 422,779 COVID-19 patients and a control group of 2,113,895 individuals were analyzed. The index date was defined as the date 3 months after confirmation of COVID-19. The incidence rate (IR) of SAT and hazard ratios (HRs) were calculated per 100,000 persons. Subgroup analysis included analysis of HRs 90–179 and 180 days post-COVID-19 diagnosis; and additional analysis was conducted according to hospitalization status, sex, and age group. Results: The IR of SAT was 17.28 per 100,000 persons (95% confidence interval [CI], 12.56 to 23.20) in the COVID-19 group and 8.63 (95% CI, 6.37 to 11.45) in the control group. The HR of COVID-19 patients was 1.76 (95% CI, 1.01 to 3.06; P=0.045). The HR of SAT was 1.39 (95% CI, 0.82 to 2.34; P=0.220) up to 6 months after the index date and 2.30 (95% CI, 1.60 to 3.30; P<0.001) beyond 6 months. The HR for SAT among COVID-19 patients was 2.00 (95% CI, 1.41 to 2.83) in hospitalized patients and 1.76 (95% CI, 1.01 to 3.06) in non-hospitalized patients compared to the control group. The IR of SAT was 27.09 (95% CI, 20.04 to 35.82) for females and 6.47 (95% CI, 3.34 to 11.30) for males. In the 19 to 64 age group, the IR of SAT was 18.19 (95% CI, 13.70 to 23.67), while the IR was 9.18 (95% CI, 7.72 to 10.84) in the 65 to 69 age group. Conclusion SAT could be a potential long-term complication of COVID-19. Long-term surveillance for thyroid dysfunction is needed especially in hospitalized, female and young-aged subjects.

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.

Background: This study evaluated the efficacy and safety of add-on gemigliptin in patients with type 2 diabetes mellitus (T2DM) who had inadequate glycemic control with metformin and dapagliflozin. Methods: In this randomized, placebo-controlled, parallel-group, double-blind, phase III study, 315 patients were randomized to receive either gemigliptin 50 mg (n=159) or placebo (n=156) with metformin and dapagliflozin for 24 weeks. After the 24-week treatment, patients who received the placebo were switched to gemigliptin, and all patients were treated with gemigliptin for an additional 28 weeks. Results: The baseline characteristics were similar between the two groups, except for body mass index. At week 24, the least squares mean difference (standard error) in hemoglobin A1c (HbA1c) changes was –0.66% (0.07) with a 95% confidence interval of –0.80% to –0.52%, demonstrating superior HbA1c reduction in the gemigliptin group. After week 24, the HbA1c level significantly decreased in the placebo group as gemigliptin was administered, whereas the efficacy of HbA1c reduction was maintained up to week 52 in the gemigliptin group. The safety profiles were similar: the incidence rates of treatment-emergent adverse events up to week 24 were 27.67% and 29.22% in the gemigliptin and placebo groups, respectively. The safety profiles after week 24 were similar to those up to week 24 in both groups, and no new safety findings, including hypoglycemia, were noted. Conclusion Add-on gemigliptin was well tolerated, providing comparable safety profiles and superior efficacy in glycemic control over placebo for long-term use in patients with T2DM who had poor glycemic control with metformin and dapagliflozin.