Does COVID-19 predispose patients to type 1 diabetes mellitus?

The novel coronavirus disease (COVID-19) has emerged as a global pandemic. This was a prospective, case-control study conducted in Izmir, Turkey. The aim of this study was to assess the relationship between COVID-19 and new-onset T1DM. We included pediatric patients (aged 6 mo-18 yr) with new-onset type-1 diabetes mellitus (T1DM) diagnosed during the COVID-19 pandemic, between April 2020 and January 2021. Polymerase chain reaction was used to diagnose COVID-19 after hospital admission. An enzyme-linked immunoassay for IgM and IgG against SARS-CoV-2 was performed after the diagnosis was confirmed. In the control group, the blood antibody test was conducted as close as possible to the time of the T1DM patient referral. A total of 118 participants were included in the study, comprising 57 (48%) patients with new-onset T1DM and 61 (52%) healthy controls. Of the 57 patients, 36 (63.2%) presented with DKA, 17 (29.7%) with diabetic ketosis, and four (7%) incidentally. The SARS-CoV-2 antibody test was positive in five (8.7%) patients with T1DM and six (10%) controls. The rate of positivity did not differ between the two groups (p = 0.901). It was not possible to demonstrate a clear association between SARS-CoV-2 infection and new-onset T1DM. Whether SARS-CoV-2 increases susceptibility to diabetes by triggering islet cell autoimmunity and affects the timing of overt diabetes in patients with existing autoimmunity should be studied in large cohorts.