Exploring the Relationship Between Acute Respiratory Illnesses, blood inflammatory biomarkers, and Acute Cardiac Events through a cross-sectional study

  1. Mohammad Abdul Aleem
  2. C. Raina Macintyre
  3. Bayzidur Rahman
  4. Mohammed Ziaur Rahman
  5. Mustafizur Rahman
  6. A. K. M. Monwarul Islam
  7. Probir Kumar Ghosh
  8. Zubair Akhtar
  9. Fahmida Chowdhury
  10. Firdausi Qadri
  11. Abrar Ahmad Chughtai
Read the full article See related articles

Discuss this preprint

Start a discussion What are Sciety discussions?

Listed in

This article is not in any list yet, why not save it to one of your lists.
Log in to save this article

Abstract

Introduction

Recent respiratory illness, especially influenza, may trigger acute cardiac events via elevated inflammatory mediators. During the 2018 influenza season in Bangladesh, this study examined whether recent acute clinical respiratory illness (CRI) or laboratory-confirmed influenza was associated with elevated hs-CRP and IL-6, linked to acute cardiac events.

Methods

A total of 139 participants aged ≥40 were recruited from a Dhaka cardiac hospital: 70 with acute myocardial infarction (AMI), 30 with other acute cardiac events, and 39 healthy individuals. CRI was defined as fever with cough and/or respiratory symptoms within seven days. Respiratory swabs were tested for influenza, and blood was analyzed for hs-CRP and IL-6.

Results

Median hs-CRP and IL-6 were higher in participants with CRI or influenza but not significantly. Cardiac patients had elevated hs-CRP (9.98 mg/L in other cardiac; 4.86 mg/L in AMI vs. 1.73 mg/L in healthy) and IL-6 (0.1 pg/mL in other cardiac; 0.145 pg/mL in AMI vs. 0.08 pg/mL in healthy) (p<0.001). CRI was not significantly associated with elevated hs-CRP or IL-6, though influenza in healthy participants was linked to higher IL-6. Cardiac patients had a higher risk of hs-CRP ≥3 mg/L and elevated IL-6.

Conclusion

Cardiac patients showed significantly increased inflammatory markers, but CRI was not clearly linked to inflammation. Further research should assess biomarker utility for early cardiac risk.

Highlights

  • The study explores inflammatory biomarkers linking recent respiratory illness and acute cardiac events.

  • Cardiac patients showed elevated hs-CRP and IL-6, confirming inflammation–cardiac risk association.

  • Association between prior influenza infection and high IL-6 was significant among healthy individuals as opposed to the cardiac group, suggesting effect modification.

  • hs-CRP and IL-6 may indicate underlying cardiac pathology and potential early cardiac risk markers.

Article activity feed

  1. Version published to 10.64898/2026.05.15.26353350 on medRxiv