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

Abstract

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.

Keywords: COVID-19; SARS-CoV-2; diabetes; type 1 diabetes; type 2 diabetes; “Post-COVID sequelae”.

Figure 1.

Screening and study selection protocol.

Figure 2.

Summary of the number of studies and number of COVID-19 patients who developed type 1 or type 2 diabetes (T1D or T2D) post-COVID-19. (a) Total number of patients who developed any type of diabetes post-COVID-19 out of the total COVID-19 patients as reported by the included studies (1.37%). (b) Total number of patients who developed diabetes post-COVID-19 with no history of diabetes or were prediabetic. (c) Number of studies that reported T1D, T2D or any type of diabetes post-COVID-19. d: Number of patients who developed T1D, T2D or any type of diabetes. All numbers are based on the studies that reported the number of patients as some studies reported cases of post-COVID-19 diabetes without reporting the numbers.

Figure 3.

Possible mechanisms for post-COVID-19 new onset diabetes.