Association between ankylosing spondylitis and neurodegenerative diseases: Systematic review and meta-analysis

Increasing evidence indicates the mechanism of overlapping immune dysfunction and inflammation disorder shared by ankylosing spondylitis (AS) and neurodegenerative diseases (NDs). However, the exact correlation between the two is still unclear. Different studies have reported inconsistent results about how AS and NDs are related.

This study aimed to investigate the association between AS and risk of NDs.

We searched electronic databases including PubMed, EMBASE, Web of Science, and Cochrane Central Register of Controlled Trials to identify studies reporting relationship between NDs risk and AS published before April 10th, 2024. Pooled odds ratios (ORs) and corresponding 95% confidence intervals (95% CIs) were estimated. All analyses were conducted using Stata V.12.0 software.

A total of 15 comparisons out of 10 studies involving 851,936 participants were included. The results showed that the risk of NDs was higher among AS patients than those who were not (OR: 1.36, 95% CI: 1.15-1.60, P<0.001). In addition, subgroup analysis showed that AS was associated with an increased risk of Parkinson's disease (PD) development (OR: 1.55, 95% CI: 1.31-1.83, P<0.001), whereas there is no observed association with Alzheimer's disease (AD) and dementia (OR: 1.22, 95% CI: 0.96-1.55, P=0.098; OR: 1.34, 95% CI: 0.96-1.87, P=0.089, respectively).

The current meta-analysis identified AS as a risk factor for the development of NDs. Clinicians should be aware of the potential association between these diseases. Further research is necessary to confirm the causal relationship and underlying mechanisms between AS and NDs.