What is ankylosing spondylitis?
Ankylosing spondylitis (AS) is a type of arthritis in which inflammatory processes lead to stiffness and fusion of vertebrae and other joints. Because AS involves axial (spine) changes detected with radiographic imaging, it can also be called radiographic axial spondyloarthritis.
What are the main symptoms of ankylosing spondylitis?
- Inflammatory back pain, which may alternate between sides of the low spine
- Sleep disturbances due to back pain
- Morning stiffness that improves with movement
- Eye inflammation
- Psoriasis[1]
- Inflammatory bowel disease[2]
How is ankylosing spondylitis diagnosed?
Diagnosis of AS is based upon a combination of clinical, laboratory, and imaging findings characteristic of the disease alongside the exclusion of other relevant diagnoses such as chronic mechanical back pain, fibromyalgia, or sacroiliac joint infection.[3]
What are some of the main medical treatments for ankylosing spondylitis?
Drugs that limit inflammation, such as non-steroidal anti-inflammatory drugs (NSAIDs), or if necessary, tumor necrosis factor alpha (TNF-alpha) inhibitors or interleukin 17 (IL-17) inhibitors. Physical therapy is often prescribed to improve balance and mobility.
Have any supplements been studied for ankylosing spondylitis?
Although some research has been conducted, there isn’t much conclusive evidence. One small trial found that high doses of omega-3 fatty acids reduced AS disease activity, and another found that nanocurcumin reduced the expression of inflammatory markers in people with AS. High serum Vitamin D is correlated with lower risk and severity of AS, but no causal evidence for this relationship exists. Finally, calcium may support bone health for people with AS and osteoporosis, but it doesn’t seem to directly influence AS itself.
How could diet affect ankylosing spondylitis?
Although 78% of individuals with AS believe diet influences their symptoms, individual preferences and sensitivities vary. A low starch diet has been proposed to reduce Klebsiella bacteria, which has been implicated in triggering spondyloarthritis activity. Research suggests the diet is effective for AS management, and results in reductions of disease activity and reliance on NSAIDs.[4]
Are there any other treatments for ankylosing spondylitis?
Symptom management strategies vary based on individual needs and the presence of comorbidities. Research suggests exercise programs can reduce AS disease activity and improve quality of life.[5]
What causes ankylosing spondylitis?
Although the cause of AS is unknown, genetics play a large role in an individual’s susceptibility. In particular, the human leukocyte antigen HLA-B27 is strongly correlated with AS.[6] Men are more likely to present with the radiographic signs of AS, but spondyloarthritis occurs with a more even frequency.[7] The absence of radiographic indications among women can result in a diagnostic delay, during which time the disease can progress unmanaged.[8]
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Frequently asked questions
Ankylosing spondylitis (AS) is a type of arthritis in which inflammatory processes lead to stiffness and fusion of vertebrae and other joints. Because AS involves axial (spine) changes detected with radiographic imaging, it can also be called radiographic axial spondyloarthritis.
Spondyloarthritis can be broadly classified as axial or peripheral, depending on where symptoms are concentrated. Axial spondyloarthritis predominantly affects the spine and sacroiliac joints; there are two types:
- Radiographic axial spondyloarthritis, also known as ankylosing spondylitis (AS), features characteristic damage on imaging
- Non-radiographic axial spondyloarthritis is characterized by similar symptoms to AS but without signs of AS on imaging
Peripheral spondyloarthritis predominantly affects areas outside the spine or sacroiliac joints, and includes:
- Psoriatic arthritis, which typically features psoriasis and is characterized by swelling of small joints in the hands and feet
- Reactive arthritis, in which symptoms are triggered by an infection
- Enteropathic arthritis, a type of arthritis associated with inflammatory bowel disease
- Undifferentiated spondyloarthritis, in which symptoms of peripheral spondyloarthritis present without a clear classification
Juvenile spondyloarthritis presents in children 16 years and younger, and can predominantly feature axial or peripheral symptoms.
- Inflammatory back pain, which may alternate between sides of the low spine
- Sleep disturbances due to back pain
- Morning stiffness that improves with movement
- Eye inflammation
- Psoriasis[1]
- Inflammatory bowel disease[2]
Inflammatory back pain generally develops gradually, whereas mechanical back pain may follow an injury. Inflammatory pain can alternate from side to side, and may cause awakening during the second half of the night. Morning stiffness is common, and may persist for 45 minutes after arising from bed. Many rheumatologists look for pain that persists for 3 months when diagnosing inflammatory back pain, and couple the diagnosis with serum markers of inflammation.[9][10][11]
Diagnosis of AS is based upon a combination of clinical, laboratory, and imaging findings characteristic of the disease alongside the exclusion of other relevant diagnoses such as chronic mechanical back pain, fibromyalgia, or sacroiliac joint infection.[3]
Drugs that limit inflammation, such as non-steroidal anti-inflammatory drugs (NSAIDs), or if necessary, tumor necrosis factor alpha (TNF-alpha) inhibitors or interleukin 17 (IL-17) inhibitors. Physical therapy is often prescribed to improve balance and mobility.
Although some research has been conducted, there isn’t much conclusive evidence. One small trial found that high doses of omega-3 fatty acids reduced AS disease activity, and another found that nanocurcumin reduced the expression of inflammatory markers in people with AS. High serum Vitamin D is correlated with lower risk and severity of AS, but no causal evidence for this relationship exists. Finally, calcium may support bone health for people with AS and osteoporosis, but it doesn’t seem to directly influence AS itself.
Although 78% of individuals with AS believe diet influences their symptoms, individual preferences and sensitivities vary. A low starch diet has been proposed to reduce Klebsiella bacteria, which has been implicated in triggering spondyloarthritis activity. Research suggests the diet is effective for AS management, and results in reductions of disease activity and reliance on NSAIDs.[4]
The guidelines for a low-starch diet generally advise reductions in bread, potatoes, chips, rice, spaghetti, cereals, cakes, and biscuits. Those foods contain indigestible starch, which passes through the small intestine intact and is fermented into sugars in the colon (large intestine). This production of sugar in the colon fuels Klebsiella growth.[12]
Symptom management strategies vary based on individual needs and the presence of comorbidities. Research suggests exercise programs can reduce AS disease activity and improve quality of life.[5]
Although the cause of AS is unknown, genetics play a large role in an individual’s susceptibility. In particular, the human leukocyte antigen HLA-B27 is strongly correlated with AS.[6] Men are more likely to present with the radiographic signs of AS, but spondyloarthritis occurs with a more even frequency.[7] The absence of radiographic indications among women can result in a diagnostic delay, during which time the disease can progress unmanaged.[8]