In a recent study published in Scientific Reports, researchers estimated the incidence of new-onset diabetes in survivors of coronavirus disease 2019 (COVID-19) employing random-effects meta-analyses using the generic inverse variance method.
Background
Studies have found an association between severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection(s) and a range of new, returning, or ongoing health problems, a condition often called long COVID-19 or post-acute sequelae of SARS-CoV-2 (PASC). Previous studies have investigated the higher risk of new-onset diabetes in survivors of COVID-19; however, the exact underlying mechanism behind its onset remains undetermined.
Moreover, the lack of a control group and small sample size limited the findings of these meta-analyses. Several interrelated processes might be involved, including stress- or steroid-induced hyperglycemia. Perhaps, SARS-CoV-2 directly or indirectly affects the β-cells of pancreatic islets.
About the study
In the present study, researchers thoroughly searched PubMed resources, such as Scopus and MEDLINE, plus the World Health Organization (WHO) Global Literature on COVID-19 and clinical trial registries between December 2019 and October 16, 2022. Two investigators independently assessed all the identified studies before inclusion and adhered to the Newcastle–Ottawa Scale for risk of bias assessment.
Study findings
The researchers identified eight studies that characterized the risk of new-onset diabetes among COVID-19 survivors; the pooled point estimate was 1.66, implying a 66% higher risk of incident diabetes. These eight studies comprised 4,270,747 COVID-19 patients and 43,203,759 controls, with 50% females, and the median age of all the participants was 43 years. Although age, gender, and study quality did not modify the risk, heterogeneity between studies was high.
The overall median risk of bias assessment was seven. However, the risk was higher in studies from the United States than in European studies (1.77 vs. 1.33). Regarding pathophysiological mechanisms governing new-onset diabetes in COVID-19 survivors, the researchers noted that SARS-CoV-2 binds to angiotensin-converting enzyme 2 (ACE-2) and transmembrane serine protease 2 (TMPRSS2) receptors in key organs and tissues. It then offsets pancreatic insulin levels and induces β cell apoptosis.
It is possible that SARS-CoV-2 cause pleiotropic alterations in glucose metabolism that lead to new-onset diabetes or facilitate a rapid transition from normal to prediabetes and diabetes states. SARS-CoV-2 works like other viruses in this aspect, like rotavirus, mumps virus, and cytomegalovirus.