Ankylosing spondylitis (AS)
Ankylosing spondylitis (AS) is a chronic inflammatory disease that may eventually lead to the fusion of certain vertebrae in the spine. Ankylosing spondylitis mainly affects the spine and may have associated peripheral arthritis, enteritis (inflammation of your small intestine), dactylitis (severe inflammation of the finger) etc.
The trend in getting younger?
The younger generation should pay more attention to this disease as ankylosing spondylitis usually initially presents during the first 30 years of life, and rarely does the first onset of ankylosing spondylitis happen after the age of 45.
According to data, the prevalence of AS ranges from 0.1% to 1.4% worldwide. The mean ankylosing spondylitis prevalence per 10000 was 23.8 in Europe, 16.7 in Asia, 31.9 in North America, 10.2 in Latin America, and 7.4 in Africa, respectively.
The disease is found more commonly in men than women.
According to the data conducted in the US, the age-adjusted incidence in males was more than three times that in females, with the highest age group between 25-34 and the lowest among those aged 55 or above.
Mean AS prevalence (per 10000)
Why getting it?
The cause of ankylosing spondylitis is still unknown nowadays.
However, it was suggested that some genes are likely related to the disease. At least 113 genetic variants contribute roughly 10% of the heritability of ankylosing spondylitis, in which gene HLA-B27 is suspected of having a major effect on the disease, as the HLA-B27 allele is found in more than 85% of ankylosing spondylitis patients.
Risk Factors
Gut inflammation: Up to 70% of ankylosing spondylitis patients have mild intestinal inflammation, while 5%–10% of these patients have more severe intestinal inflammation.
Smoking: Smoking is associated with disease activity levels in those who suffer from ankylosing spondylitis, as smoking has pro-inflammatory and pro-oxidative effects, especially when it comes to triggering disease in someone who already has a hereditary predisposition.
Consequences on our bones
Ankylosing spondylitis usually affects the spine (vertebrate), but the peripheral joints and extra-articular structures may also be affected. Ankylosing spondylitis can cause some of the bones in the spine and joint to fuse. In detail, the affected joints may show irregular erosion and sclerosis (hardening of body tissue). When these lesions occur in the spine, the outer annular fibres are replaced by bone and the vertebrae fuse, making the spine less flexible and resulting in a hunched posture.
How to prevent AS?
Reduce smoking
Since ankylosing spondylitis is thought to be caused by genes, it is suggested that people can reduce smoking in order to prevent the disease.
Take sufficient vitamin D
The lack of vitamin D may be associated with both susceptibility and disease severity in ankylosing spondylitis because both innate and acquired immunity are affected by vitamin D. It was found that ankylosing spondylitis patients had lower vitamin D levels than in the general population.
