Risk of Incident Thyroid Dysfunction in the Post-Acute Phase of COVID-19: A Population-Based Cohort Study in Hong Kong

OBJECTIVE

The evidence of thyroid dysfunction in the post-acute phase of SARS-CoV-2 infection is limited. This study aimed to evaluate the risk of incident thyroid dysfunction in the post-acute phase of COVID-19.

METHODS

This retrospective, propensity-score matched, population-based study included COVID-19 patients and non-COVID-19 individuals between January 2020 and March 2022, identified from the electronic medical records of the Hong Kong Hospital Authority. The cohort was followed up until the occurrence of outcomes, death, or 31 January 2023, whichever came first. Patients with COVID-19 were 1:1 matched to controls based on various variables. The primary outcome was a composite of thyroid dysfunction (hyperthyroidism, hypothyroidism, initiation of antithyroid drug or levothyroxine, and thyroiditis). Cox regression was employed to evaluate the risk of incident thyroid dysfunction during the post-acute phase.

RESULTS

A total of 84 034 COVID-19 survivors and 84 034 matched controls were identified. Upon a median follow-up of 303 days, there was no significant increase in the risk of diagnosed thyroid dysfunction in the post-acute phase of COVID-19 (hazard ratio [HR] 1.058, 95% confidence interval 0.979-1.144, P = .154). Regarding the secondary outcomes, patients with COVID-19 did not have increased risk of hyperthyroidism (HR 1.061, P = .345), hypothyroidism (HR 1.062, P = .255), initiation of antithyroid drug (HR 1.302, P = .070), initiation of levothyroxine (HR 1.086, P = .426), or thyroiditis (P = .252). Subgroup and sensitivity analyses were largely consistent with the main analyses.

CONCLUSION

Our population-based cohort study provided important reassuring data that COVID-19 was unlikely to be associated with persistent effects on thyroid function.

Risks of incident major osteoporotic fractures following SARS-CoV-2 infection among older individuals: a population-based cohort study in Hong Kong

Population-based epidemiological studies on post-acute phase COVID-19-related fractures in older adults are lacking. This study aims to examine the risk of incident major osteoporotic fractures following COVID-19 infection among individuals aged ≥50, compared to individuals without COVID-19. It was a retrospective, propensity-score matched, population-based cohort study of COVID-19 patients and non-COVID individuals identified from the electronic database of the Hong Kong Hospital Authority from January 2020 to March 2022. The primary outcome was a composite of major osteoporotic fractures (hip, clinical vertebral, and upper limb). COVID-19 patients were 1:1 matched to controls using propensity-score according to age, sex, vaccination status, medical comorbidities and baseline medications. Hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated using Cox proportional hazards regression models. A total of 429 459 COVID-19 patients were included, 1:1 matched to non-COVID individuals. Upon median follow-up of 11 months, COVID-19 patients had higher risks of major osteoporotic fractures (5.08 vs 3.95 per 1000 persons; HR 1.22 95%CI [1.15-1.31]), hip fractures (2.71 vs 1.94; 1.33 [1.22-1.46]), clinical vertebral fractures (0.42 vs 0.31; 1.29 [1.03-1.62]) and falls (13.83 vs 10.36; 1.28 [1.23-1.33]). Subgroup analyses revealed no significant interaction. In acute (within 30 days) and post-acute phases (beyond 30 days) following SARS-CoV-2 infection, we consistently observed a significant increase in fractures and falls risks. Our study demonstrated increased risk of major osteoporotic fractures after SARS-CoV-2 infection in both acute and post-acute phases in older adults, partly due to increased fall risk. Clinicians should be aware of musculoskeletal health of COVID-19 survivors.

Effects of SARS-CoV-2 infection on incidence and treatment strategies of hepatocellular carcinoma in people with chronic liver disease

BACKGROUND

Chronic liver disease (CLD) was associated with adverse clinical outcomes among people with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection.

AIM

To determine the effects of SARS-CoV-2 infection on the incidence and treatment strategy of hepatocellular carcinoma (HCC) among patients with CLD.

METHODS

A retrospective, territory-wide cohort of CLD patients was identified from an electronic health database in Hong Kong. Patients with confirmed SARS-CoV-2 infection [coronavirus disease 2019 (COVID-19)+CLD] between January 1, 2020 and October 25, 2022 were identified and matched 1:1 by propensity-score with those without (COVID-19-CLD). Each patient was followed up until death, outcome event, or November 15, 2022. Primary outcome was incidence of HCC. Secondary outcomes included all-cause mortality, adverse hepatic outcomes, and different treatment strategies to HCC (curative, non-curative treatment, and palliative care). Analyses were further stratified by acute (within 20 d) and post-acute (21 d or beyond) phases of SARS-CoV-2 infection. Incidence rate ratios (IRRs) were estimated by Poisson regression models.

RESULTS

Of 193589 CLD patients (> 95% non-cirrhotic) in the cohort, 55163 patients with COVID-19+CLD and 55163 patients with COVID-19-CLD were included after 1:1 propensity-score matching. Upon 249-d median follow-up, COVID-19+CLD was not associated with increased risk of incident HCC (IRR: 1.19, 95%CI: 0.99-1.42, P = 0.06), but higher risks of receiving palliative care for HCC (IRR: 1.60, 95%CI: 1.46-1.75, P < 0.001), compared to COVID-19-CLD. In both acute and post-acute phases of infection, COVID-19+CLD were associated with increased risks of all-cause mortality (acute: IRR: 7.06, 95%CI: 5.78-8.63, P < 0.001; post-acute: IRR: 1.24, 95%CI: 1.14-1.36, P < 0.001) and adverse hepatic outcomes (acute: IRR: 1.98, 95%CI: 1.79-2.18, P < 0.001; post-acute: IRR: 1.24, 95%CI: 1.13-1.35, P < 0.001), compared to COVID-19-CLD.

CONCLUSION

Although CLD patients with SARS-CoV-2 infection were not associated with increased risk of HCC, they were more likely to receive palliative treatment than those without. The detrimental effects of SARS-CoV-2 infection persisted in post-acute phase.

Incidence of diabetes following COVID-19 vaccination and SARS-CoV-2 infection in Hong Kong: A population-based cohort study

BACKGROUND

The risk of incident diabetes following Coronavirus Disease 2019 (COVID-19) vaccination remains to be elucidated. Also, it is unclear whether the risk of incident diabetes after Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection is modified by vaccination status or differs by SARS-CoV-2 variants. We evaluated the incidence of diabetes following mRNA (BNT162b2), inactivated (CoronaVac) COVID-19 vaccines, and after SARS-CoV-2 infection.

METHODS AND FINDINGS

In this population-based cohort study, individuals without known diabetes were identified from an electronic health database in Hong Kong. The first cohort included people who received ≥1 dose of COVID-19 vaccine and those who did not receive any COVID-19 vaccines up to September 2021. The second cohort consisted of confirmed COVID-19 patients and people who were never infected up to March 2022. Both cohorts were followed until August 15, 2022. A total of 325,715 COVID-19 vaccine recipients (CoronaVac: 167,337; BNT162b2: 158,378) and 145,199 COVID-19 patients were 1:1 matched to their respective controls using propensity score for various baseline characteristics. We also adjusted for previous SARS-CoV-2 infection when estimating the conditional probability of receiving vaccinations, and vaccination status when estimating the conditional probability of contracting SARS-CoV-2 infection. Hazard ratios (HRs) and 95% confidence intervals (CIs) for incident diabetes were estimated using Cox regression models. In the first cohort, we identified 5,760 and 4,411 diabetes cases after receiving CoronaVac and BNT162b2 vaccines, respectively. Upon a median follow-up of 384 to 386 days, there was no evidence of increased risks of incident diabetes following CoronaVac or BNT162b2 vaccination (CoronaVac: 9.08 versus 9.10 per 100,000 person-days, HR = 0.998 [95% CI 0.962 to 1.035]; BNT162b2: 7.41 versus 8.58, HR = 0.862 [0.828 to 0.897]), regardless of diabetes type. In the second cohort, we observed 2,109 cases of diabetes following SARS-CoV-2 infection. Upon a median follow-up of 164 days, SARS-CoV-2 infection was associated with significantly higher risk of incident diabetes (9.04 versus 7.38, HR = 1.225 [1.150 to 1.305])-mainly type 2 diabetes-regardless of predominant circulating variants, albeit lower with Omicron variants (p for interaction = 0.009). The number needed to harm at 6 months was 406 for 1 additional diabetes case. Subgroup analysis revealed no evidence of increased risk of incident diabetes among fully vaccinated COVID-19 survivors. Main limitations of our study included possible misclassification bias as type 1 diabetes was identified through diagnostic coding and possible residual confounders due to its observational nature.

CONCLUSIONS

There was no evidence of increased risks of incident diabetes following COVID-19 vaccination. The risk of incident diabetes increased following SARS-CoV-2 infection, mainly type 2 diabetes. The excess risk was lower, but still statistically significant, for Omicron variants. Fully vaccinated individuals might be protected from risks of incident diabetes following SARS-CoV-2 infection.

Risk of thyroid dysfunction associated with mRNA and inactivated COVID-19 vaccines: a population-based study of 2.3 million vaccine recipients

BACKGROUND

In view of accumulating case reports of thyroid dysfunction following COVID-19 vaccination, we evaluated the risks of incident thyroid dysfunction following inactivated (CoronaVac) and mRNA (BNT162b2) COVID-19 vaccines using a population-based dataset.

METHODS

We identified people who received COVID-19 vaccination between 23 February and 30 September 2021 from a population-based electronic health database in Hong Kong, linked to vaccination records. Thyroid dysfunction encompassed anti-thyroid drug (ATD)/levothyroxine (LT4) initiation, biochemical picture of hyperthyroidism/hypothyroidism, incident Graves' disease (GD), and thyroiditis. A self-controlled case series design was used to estimate the incidence rate ratio (IRR) of thyroid dysfunction in a 56-day post-vaccination period compared to the baseline period (non-exposure period) using conditional Poisson regression.

RESULTS

A total of 2,288,239 people received at least one dose of COVID-19 vaccination (57.8% BNT162b2 recipients and 42.2% CoronaVac recipients). 94.3% of BNT162b2 recipients and 92.2% of CoronaVac recipients received the second dose. Following the first dose of COVID-19 vaccination, there was no increase in the risks of ATD initiation (BNT162b2: IRR 0.864, 95% CI 0.670-1.114; CoronaVac: IRR 0.707, 95% CI 0.549-0.912), LT4 initiation (BNT162b2: IRR 0.911, 95% CI 0.716-1.159; CoronaVac: IRR 0.778, 95% CI 0.618-0.981), biochemical picture of hyperthyroidism (BNT162b2: IRR 0.872, 95% CI 0.744-1.023; CoronaVac: IRR 0.830, 95% CI 0.713-0.967) or hypothyroidism (BNT162b2: IRR 1.002, 95% CI 0.838-1.199; CoronaVac: IRR 0.963, 95% CI 0.807-1.149), GD, and thyroiditis. Similarly, following the second dose of COVID-19 vaccination, there was no increase in the risks of ATD initiation (BNT162b2: IRR 0.972, 95% CI 0.770-1.227; CoronaVac: IRR 0.879, 95%CI 0.693-1.116), LT4 initiation (BNT162b2: IRR 1.019, 95% CI 0.833-1.246; CoronaVac: IRR 0.768, 95% CI 0.613-0.962), hyperthyroidism (BNT162b2: IRR 1.039, 95% CI 0.899-1.201; CoronaVac: IRR 0.911, 95% CI 0.786-1.055), hypothyroidism (BNT162b2: IRR 0.935, 95% CI 0.794-1.102; CoronaVac: IRR 0.945, 95% CI 0.799-1.119), GD, and thyroiditis. Age- and sex-specific subgroup and sensitivity analyses showed consistent neutral associations between thyroid dysfunction and both types of COVID-19 vaccines.

CONCLUSIONS

Our population-based study showed no evidence of vaccine-related increase in incident hyperthyroidism or hypothyroidism with both BNT162b2 and CoronaVac.