Covid -19, An Acute on Chronic Metabolic Syndrome? HbA1c-A Marker of Severe Infection.

Abstract Background: The comorbidities commonly observed in severe Covid-19 are diagnoses that comprise the metabolic syndrome. The metabolic status of patients when infected with SARS-Cov-2 and its significance for the severity of the disease is not yet fully understood. We investigated the association between respiratory symptoms and the levels of HbA1c in hospitalized patients infected with SARS-CoV-2. Methods: In this retrospective observational study, we included all inpatients at the Karolinska University Hospital, Sweden who had both a positive SARS-CoV-2 test and who had a HbA1c test obtained within 3 months of admission. The primary reasons for hospitalization included trauma, stroke, myocardial infarction, acute or elective surgery as well as infection. Based on HbA1c level and diabetes history, we classified patients into the following dysglycemia categories: prediabetes, unknown diabetes, controlled diabetes or uncontrolled diabetes. We used multivariable logistic regression analysis adjusted for age, sex and body mass index, to assess the association between dysglycemia categories and development of respiratory failure when infected with SARS-CoV-2. Primary outcome was respiratory failure associated with SARS-CoV-2.Results: Of the 385 study patients, 88 (22.9%) had prediabetes, 68 (17.7%) had unknown diabetes, 36 (9.4%) had controlled diabetes, and 83 (21.6%) had uncontrolled diabetes. Overall, 299 (77.7%) patients were admitted with or developed SARS-CoV-2-assoociated respiratory failure during hospitalization. The proportion of patients in need of intensive care (62.5% vs 26.7%, p<0.001), mechanical ventilation (60.9% vs. 26.7%, p<0.001) and renal replacement therapy (14% vs. 1.2%, p<0.001) were all higher in patients with SARS-CoV-2 associated respiratory failure vs. patients without. In addition, 83% of the ICU patients with SARS-CoV-2 associated respiratory failure had a HbA1c > 42 mmol/mol. In multivariable logistic regression analysis compared with no chronic dysglycemia, prediabetes (OR 14.41, 95% CI 5.27-39.43), unknown diabetes (OR 15.86, 95% CI 4.55-55.36), and uncontrolled diabetes (OR 17.61, 95% CI 5.77-53.74) was independently associated with increased risk of SARS-CoV-2-induced respiratory failure.Conclusion: Metabolic imbalance, reflected by elevated HbA1c with or without previous diagnosed diabetes mellitus, was associated with a more severe course of SARS-CoV-2-respratory infection. We suggest that HbA1c could be used as a marker of risk for severe Covid-19.