Here’s a breakdown of the key findings from the study on SARS-CoV-2 infection in lean and obese macaques:
Main Findings:
Differential Long-Term Effects: The study found that the long-term consequences of SARS-CoV-2 infection differed significantly between lean and obese macaques.
Widespread Long COVID: Long COVID symptoms (post-acute sequelae of COVID or PASC) were found to be widespread in the animals studied, even after seemingly mild initial infections.
Obesity-Specific Risks: Obesity was associated with increased risks of persistent lung damage and longer-term weight loss.
Lean Animal Risks: Lean animals were more prone to developing signs of metabolic disruption. A notable finding was a meaningful decline in the adiponectin to leptin ratio in lean animals, bringing their metabolic health marker down to the level seen in obese individuals.
Physiological vs. Symptomatic: Many long-term effects were physiological rather than symptomatic, suggesting that long COVID might be more prevalent than human self-report data indicates.
Obesity-Dependent and Independent Effects: The authors concluded that persistent effects of SARS-CoV-2 infection are both dependent on and independent of obesity.
Delayed symptom Onset: Some symptoms of long COVID may not become apparent untill long after the initial infection, as evidenced by increased inflammatory factors and changes in cardiometabolic disease risk biomarkers observed 6 months post-infection.
Study Details:
Model: Adult male rhesus macaques.
Infection: SARS-CoV-2 delta variant.
Duration: 6-month time course.
Comparison Groups: Lean and obese/insulin-resistant macaques.
Key Measurements: Virus levels in the respiratory system, viral antibodies, inflammatory factors in blood, lung damage, weight changes, and hormone levels (adiponectin and leptin).
Significance:
Understanding Long COVID: The study provides valuable insights into how pre-existing conditions like obesity can influence the long-term impact of COVID-19.
macque model for Research: The development of this macaque model of long COVID is crucial for future research,allowing for direct comparisons of different SARS-CoV-2 variants (like delta vs.omicron) without the confounding factor of pre-existing immunity in humans.
* implications for Human Health: The findings suggest that even mild COVID-19 infections can lead to significant long-term physiological changes, and that metabolic health plays a critical role in these outcomes.