# The metabolic-immune interface of obesity in Covid-19: a role for angiotensin ii and inflammatory cytokines

## TL;DR

Obesity worsens COVID-19 outcomes by increasing inflammation and RAAS imbalance, with angiotensin II and cytokines as potential early indicators.

## Contribution

Identifies angiotensin II and inflammatory cytokines as predictive biomarkers linking obesity to severe COVID-19.

## Key findings

- Obese patients had higher Ang II, IL-1β, IL-6, and TNF, and lower IL-10 compared to lean individuals.
- Ang II levels positively correlated with BMI, and severe cases required more ventilatory support.
- Mortality occurred only in obese patients, highlighting the role of metabolic-immune interactions in disease severity.

## Abstract

Obesity is a major risk factor for severe COVID-19, partly explained by chronic systemic low-grade inflammation and renin-angiotensin-aldosterone system (RAAS) dysregulation.

To investigate the relationship between obesity and COVID-19 severity by measuring plasma angiotensin II (Ang II) and pro and anti-inflammatory cytokines across BMI categories.

In a cross-sectional cohort of 142 adults (Lean and Obese), including mild and severe COVID-19 cases and matched uninfected controls. Plasma Ang II, IL-1β, IL-6, IL-10, and TNF were quantified by ELISA. Associations with BMI and clinical severity were assessed using ANOVA and correlation analyses.

Obese patients showed elevated Ang II, IL-1β, IL-6, and TNF, alongside reduced IL-10, compared to lean individuals and controls. Ang II positively correlated with BMI. Severe cases showed elevated neutrophil-to-lymphocyte ratios and greater need for ventilatory support requirements. Notably, mortality occurred exclusively among obese patients.

Obesity exacerbates COVID-19 severity through RAAS imbalance and, amplified inflammatory responses. Ang II and pro-inflammatory cytokines may serve as early predictive biomarkers of disease progression in obese individuals, highlighting the metabolic-immune interface as a critical determinant of COVID-19 outcomes.