Assessing the Relationship Between D-dimer and IL-6 Levels and Clinical Outcomes in Elderly COVID-19 Patients

Abstract

Background: This study aimed to evaluate serum levels of interleukin-6 (IL-6) and D-dimer and their association with morbidity and mortality in elderly coronavirus disease-19 (COVID-19) patients and to assess their clinical outcomes. Materials & Methods: This retrospective observational study was conducted on elderly COVID-19 patients (≥60 years) diagnosed via reverse transcription-polymerase chain reaction (RT-PCR) or radiological tests in a South Indian tertiary care hospital. Data encompassed demographics, comorbidities, symptoms, IL-6 and D-dimer levels, oxygen (O 2 ) requirement, duration of hospital stay, and outcomes. Statistical analysis involved Chi-square test. A p-value of < .05 was considered statistically significant.Findings: Among 1448 screened patients, 1380 patients with a mean age of 68.85±6.985 years were included in this study, of whom 61.67% were male. The mortality rate was 12.1% in males and 11% in females. Fever, cough, hypertension, and diabetes were common in most of the patients. The mean D-dimer and IL-6 levels were 2.687±5.189 mg/L fibrinogen equivalent units (FEU) and 95.72±335.62 pg/mL, respectively. Elevated D-dimer (71%) and IL-6 (87.7%) levels were significantly associated with oxygen requirement, morbidity, and mortality (p= .000). Sub-group analysis revealed a significant association between D-dimer and IL-6 levels and O 2 requirement and mortality in diabetic and hypertensive patients (p= .000). Conclusion: Serum IL-6 and D-dimer levels are significantly associated with morbidity and mortality in elderly COVID-19 patients. Elevated levels of these biomarkers also influence O 2 requirement and mortality in patients with comorbidities, suggesting their potential use in risk stratification and management strategies for this vulnerable population.