New onset of type 1 and type 2 diabetes post-COVID-19 infection: a systematic review

COVID-19 may primarily cause respiratory symptoms but can lead to long-term effects known as long COVID. COVID-19-induced diabetes mellitus was reported in many patients which shares characteristics of types 1 and 2 (T1DM and T2DM). This study aims to identify and analyse the reported cases of new onset diabetes post-COVID-19 infection. Several databases were used to conduct a comprehensive literature search to target studies reporting cases of T1DM or T2DM post-COVID-19 infection. Screening, data extraction, and cross-checking were performed by two independent reviewers. Only 43 studies met our inclusion criteria. Our results revealed that the overall prevalence of new onset diabetes post-COVID-19 was 1.37% with higher prevalence for T2DM (0.84%) as compared to T1DM (0.017%) while the type of diabetes was not reported in 0.51% of the cases. Several risk factors for developing diabetes post-COVID-19 infection were identified including the type of SARS-CoV-2 variant, age, comorbidities, and the vaccination status. The direct viral attack of the pancreatic beta cells as well as inflammation and the anti-inflammatory corticosteroids were proposed as possible mechanisms of the COVID-19 induced diabetes. A multidisciplinary approach involving endocrinologists, primary care physicians, and infectious disease specialists should be implemented in the management of post-COVID patients to address both the acute and long-term complications, including metabolic changes and risk of diabetes.