Incidence of diabetes following COVID-19 vaccination and SARS-CoV-2 infection: a population-based cohort study. The Endocrine Society’s 105th Annual Meeting, Chicago, June 2023.

Abstract

<p><strong>Objectives: </strong>The risk of incident diabetes following COVID-19 vaccination remains to be evaluated. Also, it is unclear whether the risk of incident diabetes after 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. <strong>Methods: </strong>Two separate COVID-19 vaccination and infection cohorts were extracted from a population-based electronic health database in Hong Kong. The vaccination cohort included people who received ≥ 1 dose of COVID-19 vaccine between February and September 2021, matched with those who did not receive any COVID-19 vaccines up to September 2021. The infection cohort consisted of confirmed COVID-19 patients between January 2020 and March 2022, and people who were never infected up to March 2022. Both cohorts were followed until 15 August 2022. COVID-19 vaccine recipients and COVID-19 patients were 1:1 matched to their respective controls using propensity score. Hazard ratios (HRs) for incident diabetes were estimated using Cox regression models. <strong>Results:</strong> In the vaccination cohort, we included 167337 CoronaVac and 158378 BNT162b2 recipients with their respective 1:1 matched control. 442 (0.3%) CoronaVac recipients and 693 (0.4%) BNT162b2 recipients were COVID-19 survivors. Upon median follow-up (FU) of 13 months (IQR 11-14), CoronaVac or BNT162b2 vaccination was not associated with increased risks of incident diabetes (CoronaVac: HR=1.00 [95%CI 0.96-1.04]; BNT162b2: HR=0.86 [95%CI 0.83-0.90]), regardless of type 1 or 2. In the infection cohort, we included 145199 COVID-19 patients and 145199 matched controls. Among COVID-19 survivors, 60348 (41.6%) were fully vaccinated and 25792 (17.8%) did not receive any COVID-19 vaccines. Upon median FU of 5 months (IQR 5-6), 2109 COVID-19 patients (all type 2 diabetes) and 1775 non-COVID-19 people (one case of type 1 diabetes) were diagnosed with diabetes following SARS-CoV-2 infection. SARS-CoV-2 infection was associated with significantly higher risk of incident diabetes (1.45% vs 1.22%, HR=1.23 [95%CI 1.15-1.31]) regardless of the predominant circulating variants (non-Omicron, HR=1.87 [95%CI 1.35-2.59]; Omicron, HR=1.21 [95%CI 1.13-1.29]), albeit lower with Omicron variants (p for interaction=0.009). Subgroup analysis showed that fully vaccinated COVID-19 survivors did not have increased risk of incident diabetes (HR=1.01 [95%CI 0.90-1.12]). <strong>Conclusions: </strong>COVID-19 vaccination was not associated with increased risk of incident diabetes. 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 the risk of incident diabetes following SARS-CoV-2 infection.<br></p>