In a recent study published in Journal of Sport and Health Science, a group of researchers evaluated the impact of exercise training on reducing inflammation in adolescents and adults with autoimmune diseases through a systematic review of studies published over two decades.
Study: The anti-inflammatory effects of exercise on autoimmune diseases: A twenty-year systematic review. Image Credit: Ground Picture/Shutterstock.com
Background
The global rise in autoimmune diseases, driven by environmental and lifestyle factors, presents major challenges to individuals and healthcare systems. Lifelong management is often necessary, with physical inactivity worsening conditions.
In conjunction with medical treatment, exercise is recommended to improve the quality of life, improve physical health, and alleviate symptoms.
Regular exercise is scientifically recognized for its anti-inflammatory benefits. It is attributed to its role in hormone and myokine release that suppress pro-inflammatory cytokines, mobilize immune cells such as regulatory T (Treg) cells, natural killer (NK) cells, and decrease visceral fat, thereby mitigating systemic inflammation.
Further research is needed to clarify the specific mechanisms by which exercise modulates immune responses and to identify optimal exercise protocols for individual autoimmune diseases.
About the study
The present systematic review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and was registered in the International Database of Prospectively Registered Systematic Reviews (PROSPERO) database.
A comprehensive literature search was conducted across PubMed, Web of Science, and Embase, targeting studies published from January 2003 to August 2023 that explored exercise interventions in autoimmune disease patients.
Both randomized and non-randomized controlled trials examining the impact of exercise on inflammation-related biomarkers were considered for inclusion.
The review team, comprising members with expertise in various medical specialties, developed the search criteria to capture a broad spectrum of relevant studies.
Inclusion criteria were set to encompass experimental studies focused on exercise's effects on inflammation biomarkers in autoimmune diseases, with no restrictions on exercise type or intervention mode. Studies were excluded if they involved non-autoimmune diseases or combined exercise with non-exercise interventions.
After deduplication and screening processes, the selected studies underwent a thorough independent review by authors, with any differences resolved through discussion. Data extraction was precisely carried out, emphasizing study design, participant demographics, exercise intervention details, and inflammation-related outcomes.
The quality of studies and risk of bias were assessed using the Tool for the assessment of Study qualiTy and reporting in EXercise (TESTEX) scale and the Cochrane tool, ensuring a rigorous evaluation of the evidence base.
Study results
In the comprehensive search that culminated in the review of 14,565 records, 736 full-text articles were scrutinized for eligibility after deduplication and relevance checks.
Ultimately, 87 studies were deemed fit for inclusion in this systematic review. These studies spanned from January 1, 2003, to August 31, 2023, encompassing research from 25 countries and involving 2,779 participants diagnosed with various autoimmune diseases.
Multiple sclerosis (MS) emerged as the most frequently studied condition, followed by rheumatoid arthritis (RA), type 1 diabetes (T1D), and systemic lupus erythematosus (SLE), among others.
The demographic spread included both adults and adolescents, with a notable focus on age and gender as factors influencing both the efficacy of exercise interventions and the prevalence of autoimmune diseases.
The exercise interventions assessed in these studies varied widely, including acute and regular exercise programs across different exercise modalities such as aerobic training (AT), resistance training (RT), high-intensity interval training (HIIT), and others like yoga, Pilates, and Tai Chi.
The studies collectively underscored the frequency of exercise sessions, which ranged from 3 to 5 times per week, and detailed the exercise protocols employed.
Safety data were also collected, focusing on participant withdrawal reasons and any adverse events recorded during the exercise interventions.
The findings from these studies illuminate the effects of exercise on inflammatory biomarkers across different autoimmune diseases.
For instance, in MS, regular exercise interventions demonstrated anti-inflammatory benefits through reductions in C-Reactive Protein (CRP), interleukin (IL)-6, and tumor necrosis factor (TNF)-α, alongside improvements in clinical disability, fatigue, mood, and other health outcomes.
Similar patterns of benefit were observed in RA, with exercise leading to reductions in inflammatory markers and enhancements in disease activity and physical fitness.
However, in conditions like T1D and SLE, the impact of exercise on inflammatory markers was less consistent, indicating the complex interplay between exercise and autoimmune pathology.
The quality and risk of bias assessments revealed varied scores across the included studies, highlighting the need for stringent methodological standards in future research.
While most studies showed low risk in several bias categories, challenges in blinding participants and personnel due to the nature of exercise interventions were noted.
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