The effects of exercise therapy on immune cells and function in patients with overweight or obesity: A systematic review

Abstract

Background

Obesity is a global health challenge linked to chronic inflammation and numerous diseases. The immune dysregulation in obesity is characterized by increased pro-inflammatory cytokines and decreased anti-inflammatory cytokines. Exercise is known to modulate immune function and inflammation, but its specific effects on immune cells in overweight and obese individuals need further exploration. This systematic review aims to summarize the impact of exercise interventions on immune cells in this population.

Materials and methods

A systematic review was conducted according to the PRISMA guidelines. Articles were sourced from PubMed, SCOPUS, COCHRANE, and Ovid up to June 14, 2024. Keywords included "Exercise Therapy", "physical activity", "Immune System", "immune modulation", "Obesity", "overweight", and "adiposity". Studies were included if they involved overweight or obese individuals undergoing exercise therapy for more than three weeks and measured immune cell outcomes. Articles discussing only inflammatory markers or genetic pathways were excluded. Methodological quality was assessed using the Newcastle-Ottawa scale (NOS), and inter-rater agreement was calculated with Cohen’s kappa

Results

From 2571 articles, 12 studies met the inclusion criteria. Exercise interventions varied widely but generally included aerobic, resistance, high-intensity interval training (HIIT), and combined regimens. Results demonstrated significant reductions in pro-inflammatory cells (e.g., neutrophils, monocytes) and increased anti-inflammatory responses (e.g. immunoglobulins). High-intensity training showed substantial immunomodulatory effects, while moderate exercise was associated with enhanced immune function without suppression. We observed that neutrophils, monocytes, and lymphocytes were the primary immune cells showing significant changes in response to various exercise interventions. These changes strongly correlated with improvements in inflammatory markers such as CRP and IL-6, which were consistently reduced following regular exercise.

Conclusion

Given the variability in exercise interventions, it is crucial to develop standardized exercise recommendations that can be tailored to the needs of overweight and obese individuals, taking into account factors such as age, gender, and baseline health status. Exercise therapy significantly influences immune cell profiles in overweight and obese individuals, reducing chronic inflammation and enhancing immune function. High-intensity training is particularly effective in reducing pro-inflammatory markers, while moderate exercise supports overall immune health. Tailored exercise programs are crucial for optimizing these benefits, with future studies needed to refine exercise recommendations for this demographic.