key: cord-0814638-1la5wrc9 authors: Sathish, Thirunavukkarasu; Cao, Yingting; Kapoor, Nitin title: Preexisting prediabetes and the severity of COVID-19 date: 2020-09-09 journal: Prim Care Diabetes DOI: 10.1016/j.pcd.2020.09.002 sha: d16664e38aa21dffa8877b2e7c0f5aabc4571c3f doc_id: 814638 cord_uid: 1la5wrc9 nan The emergence of a novel coronavirus disease in Wuhan, China, is spreading rapidly across the globe. A frequent preexisting comorbidity in COVID-19 patients is type 2 diabetes [1] . Several reports published in Primary Care Diabetes and elsewhere have consistently shown that preexisting type 2 diabetes is associated with the disease severity of COVID-19. This includes increased episodes of acute respiratory distress syndrome, intensive care unit admission, mechanical ventilation, and mortality [2, 3] . However, the impact of preexisting prediabetes on the course of this disease is far less well studied. Prediabetes and type 2 diabetes share similar pathophysiology, with the two primary defects being impaired insulin secretion and insulin resistance [4] . Most importantly, the key underlying mechanisms behind the severity of COVID-19 in known type 2 diabetes patients, including chronic low-grade inflammation, impaired innate immunity, poor adaptive immune response to infections, and pro-coagulative state [2] , also characterize the prediabetes phenotype, although to a lesser degree than type 2 diabetes [4] . Thus, it can be hypothesized that people with preexisting prediabetes could also experience poor outcomes of COVID-19. For example, in a study by Li et al. in China, out of 453 hospitalized COVID-19 patients, 129 (28.5%) had possible preexisting prediabetes (fasting plasma glucose (FPG) 5.6-6.9 mmol/l and/or HbA1c 5.7-6.4%) [5] . This was associated with a trend towards a higher risk of mortality (Hazard ratio 3.30, 95% CI 0.65, 16.6), compared with those with normal glucose. In a large suburban hospital study from New Jersey, among 184 hospitalized COVID-19 patients, 44 (23.9%) had preexisting prediabetes (HbA1c 5.7-6.4%) [6] . Slightly more than 50% of these patients had persistently elevated FPG in the absence of steroid therapy. These preliminary observations suggest that preexisting prediabetes is much more prevalent in COVID-19 patients than known type 2 diabetes (7 to 17% depending on the disease severity) [1] . They also provide early indications for a possible association between preexisting prediabetes and COVID-19 disease severity. However, large-scale observational studies are required to study this relationship further. To ascertain the status of preexisting prediabetes, it is essential that clinicians utilize the electronic health records and/or screen all COVID-19 patients with HbA1c in addition to blood glucose [7] . Compared with type 2 diabetes, prediabetes is highly common, the prevalence is rapidly increasing, and most people are unaware of their high-risk status [8] . Thus, even its minimal influence on COVID-19 can impact a large number of individuals. It is therefore crucial to understand the link between preexisting prediabetes and the severity of COVID-19. J o u r n a l P r e -p r o o f Prevalence of diabetes mellitus in 2019 novel coronavirus: A meta-analysis COVID-19 in people with diabetes: understanding the reasons for worse outcomes Diabetes and COVID-19: A pooled analysis related to disease severity and mortality Profile of the Immune and Inflammatory Response in Individuals With Prediabetes and Type 2 Diabetes Newly diagnosed diabetes is associated with a higher risk of mortality than known diabetes in hospitalized patients with COVID-19 Impaired glucose metabolism in patients with diabetes, prediabetes, and obesity is associated with severe COVID-19 Newly diagnosed diabetes in COVID-19 International Diabetes Federation, IDF Diabetes Atlas None of the authors have any financial disclosures. None of the authors have any conflict of interest.