Admission eGFR predicts in-hospital mortality independently of admission glycemia and C-peptide in patients with type 2 diabetes mellitus and COVID-19

Abstract

Objective

Type 2 diabetes mellitus (T2DM) and impaired kidney function are associated with a higher risk of poor outcomes of coronavirus disease 2019 (COVID-19). We conducted a retrospective study in hospitalized T2DM patients with COVID-19 to assess the association between in-hospital mortality and admission values of different hematological/biochemical parameters, including estimated glomerular filtration rate (eGFR), plasma glucose and C-peptide (the latter serving as a marker of beta-cell function).

Methods

The study included T2DM patients with confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection who were consecutively admitted to our Institution between 1 October 2020 and 1 April 2021.

Results

Patients (n = 74) were categorized into survivors (n = 55) and non-survivors (n = 19). Non-survivors exhibited significantly higher median white blood cell (WBC) count, D-dimer, neutrophil-to-lymphocyte ratio, high-sensitivity C-reactive protein (hsCRP), and procalcitonin levels, as well as significantly lower median serum 25-hydroxyvitamin D [25(OH)D] levels compared to survivors. Non-survivors exhibited significantly higher median admission plasma glucose (APG) values compared to survivors (210 vs. 166 mg/dL; p = .026). There was no statistically significant difference in median values of (random) plasma C-peptide between non-survivors and survivors (3.55 vs. 3.24 ng/mL; p = .906). A significantly higher percentage of patients with an eGFR < 60 mL/min/1.73 m² was observed in the non-survivor group as compared to the survivor group (57.9% vs. 23.6%; p = .006). A multivariate analysis performed by a logistic regression model after adjusting for major confounders (age, sex, body mass index, major comorbidities) showed a significant inverse association between admission eGFR values and risk of in-hospital mortality (OR, 0.956; 95% CI, 0.931-0.983; p = .001). We also found a significant positive association between admission WBC count and risk of in-hospital mortality (OR, 1.210; 95% CI, 1.043–1.404; p = .011).

Conclusions

Admission eGFR and WBC count predict in-hospital COVID-19 mortality among T2DM patients, independently of traditional risk factors, APG and random plasma C-peptide. Hospitalized patients with COVID-19 and comorbid T2DM associated with impaired kidney function at admission should be considered at high risk for adverse outcomes and death.

Keywords:

• SARS-CoV-2
• T2DM
• kidney function
• admission glycemia
• beta-cell function
• inflammation
• mortality

Transparency

Declaration of funding

The authors received no funding for this article.

Declaration of financial/other relationships

The authors declare that they have no financial, employment and other significant/relevant relationships to disclose. Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Author contributions

Marco Infante and Maria Morello conceived and designed the research project, wrote the paper, interpreted data, supervised the project and equally contributed to the manuscript. Santina Lupisella, Ali Mohamad Lorenzo Ansaldo and Angela Crea collected and retrieved clinical and biochemical data, analyzed results and contributed to the research project. Massimo Pieri performed the statistical analysis. Sergio Bernardini, David Della-Morte, Andrea Fabbri, Alberto De Stefano, Marco Iannetta and Massimo Andreoni supervised the research project, revised and approved the final version of the manuscript. All authors read, edited and approved the final version of the manuscript.

Acknowledgements

Authors acknowledge all medical staff involved in the diagnosis and treatment of patients with COVID-19 at our Institution.

Data availability statement

Data supporting the findings of this study are available from the corresponding author, [MM], upon reasonable request.