Can HbA1c levels be used as an independent marker of mortality and morbidity risk in patients with COVID-19 positive swabs?

ABSTRACT

Background: Diabetes mellitus has been considered a significant risk factor for morbidity and mortality for COVID-19.1 HbA1c levels are often used as a marker of poor glycaemic control and are one way of diagnosing pre-diabetes as well as diabetes.2,3 We tried to explore whether HbA1c levels could be an independent risk factor for mortality and morbidity in patients with positive coronavirus (SARS-COv-2) swabs. Methods: This was a retrospective multicentre study of coronavirus swab positive patients who had a recent HbA1c test. Their demographic data, medical history, COVID-19 swab and laboratory results, and final outcomes were analysed. Patients were divided into three groups;HbA1c in normal (group 1), pre-diabetic (group 2) and diabetic (group 3) ranges. Data were analysed using JASP and statistical computation using a χ2 test. Results: A total of 1,226 patients had SARS-CoV-2 RNA identification swabs between 10 February 2020 and 1 May 2020. A cohort of 120 of these patients had positive swab results and recent HbA1c results. Mortality rates for group 1 (normal HbA1c) and 3 (diabetic HbA1c) were relatively higher than group 2 (pre-diabetic HbA1c). Among group 2, female patients had greater mortality, perhaps because of fewer male patients, although overall co-morbidity was less (4/120 (3.33%) in group 2 compared with 18/120 (15%) in group 1 and 14/120 (11.66%) in group 3. Overall, 36/120 (30%) patients died and 84/120 (70%) survived. Survival curves after analysis of data showed that increasing HbA1c levels were associated with poorer outcomes across all groups. Analysis was significant with p=0.003. Conclusions: HbA1c levels in this study were an independent marker of increased risk of mortality in COVID-19 swab positive patients. The findings are statistically significant (p=0.003). Increased co-morbidities at normal HbA1c seem to have a contributing role in enhanced mortality.