The effect of COVID-19 pandemic on new-onset adult diabetes and its one-year follow-up.

Aims: Bidirectional detrimental relationships between COVID-19 infection and diabetes have been described globally. However, new-onset diabetes in adults and its follow-up during the pandemic have not been sufficiently investigated. In this study, new-onset autoimmune and type 2 diabetes cases during the pandemic were compared to those before the pandemic, and the clinical course of new-onset diabetes during the pandemic was examined.

Methods: In this single-center retrospective cohort study, clinical and laboratory characteristics of new-onset diabetes patients before the pandemic (n = 161) and during the pandemic (n = 144) were evaluated between March 2018 and March 2022.

Results: A 1.85-fold increase in new-onset adult diabetes cases was observed during the pandemic compared to pre-pandemic period (p = 0.010), while the proportion of autoimmune and type 2 diabetes (T2D) did not change. During the pandemic, there was a 6.2-fold increase in autoimmune diabetes presented with DKA (p = 0.003). Insulin was preferred 1.7 times more frequently as initial treatment during the pandemic (p = 0.014), and mean HbA1c (p = 0.003) and C-peptide (p = 0.010) were higher. Clinical and laboratory data did not differ between PCR (+) and PCR (-) patients. At one-year follow-up, while only HbA1c decreased in the autoimmune diabetes; in T2D group fasting glucose, HbA1c, C-peptide, and lipid profile were significantly improved.

Conclusions: The pandemic led to increased new-onset adult diabetes presented with DKA. However, clinical and laboratory features were similar between PCR positive and negative cases. PCR-confirmed COVID-19 may not adversely affect the medium-term clinical course of new diabetes in adults.