Immune-inflammatory biomarkers and the risk of cardiac injury in COVID-19 patients with diabetes: a retrospective cohort study

Background: To determine the risk-assessment role of the immune-inflammatory biomarkers on myocardial damage in COVID-19 patients with diabetes mellitus (DM).

Methods: This retrospective study was conducted on 822 COVID-19 inpatients from 1 January to 10 March 2020 at Renmin Hospital of Wuhan University. The demographic data, clinical data, and immune-inflammatory parameters of participants were collected. The predictors of cardiac injury were assessed by Logistics regression analysis.

Results: A total of 246 COVID-19 inpatients were diagnosed with DM (29.9%). The incidence of cardiac injury was higher in patients with DM than in non-DM cases (28.9% vs 9.0%, p < 0.001), even grouped by age, gender, and the level of fasting plasma glucose (FPG). The mortality in diabetic COVID-19 patients with cardiac injury and without cardiac injury was 42.9% and 3.4%, respectively (p < 0.001). COVID-19 patients with DM and cardiac injury presented a decreased number of immunocyte subsets, lower C3 concentration, and a higher level of interleukin-6 (IL-6) and immunoglobulin A (IgA). The independent risk factors for cardiac injury in COVID-19 patients with DM were CD3⁺CD4⁺ T cells counts ≤ 288 cells/μl (adjusted Odds ratio (OR), 2.501; 95% confidence interval (CI) 1.282-4.877; p = 0.007) and IL-6 > 25.68mpg/ml (adjusted OR, 4.345; 95% CI 2.192-10.374; p < 0.001) (all P_interaction < 0.05).

Conclusions: For diabetic patients with COVID-19, cardiac injury not only induce severer immune-inflammatory responses, but also increase in-hospital mortality. The decreased number of CD3⁺CD4⁺ T cells and increased IL-6 are recommended to distinguish the people who refer to high risk of cardiac injury and mortality from those persons. However, it remains a testable theory whether decision-making strategies based on the risk status of cardiac injury in COVID-19 patients, especially with DM, would be expected to get better outcomes.