Who Gets Ankylosing Spondylitis?

A skeleton of the pelvis, sacrum, lumbar spine, hip joints and femur bones.
A skeleton of the pelvis, sacrum, lumbar spine, hip joints and femur bones. sciencepics

Ankylosing spondylitis, (AS) is a chronic, debilitating, painful type of inflammatory arthritis that affects the hips, pelvis and especially the spine.

Contrary to what many people believe, ankylosing spondylitis is not a rare disease. Rather, the Spondylitis Association of America says it is more prevalent than multiple sclerosis, cystic fibrosis and Lou Gehrig's disease combined.

For a number of reasons, AS is particularly tricky to diagnose.

The Spondylitis Association reports that getting an accurate diagnosis can take up to 10 years from the time the first symptom is experienced, and that along the way, patients often have to see five or more health professionals. Over 60% (finally) get their diagnosis from a rheumatologist.

But as more people get diagnosed and research studies are completed, our understanding of who is most vulnerable to AS grows.This article talks about who is likely to develop AS, and why one particular AS demographic may someday go down in medical history as a myth.

AS and Age

AS has a reputation as a young man's disease; this is in contrast to many other forms of arthritis that are associated with the aging process.

The Spondylitis Association of America characterizes AS as arthritis of the spine that strikes young people.

The main symptom of AS is an inflammatory type of back pain. It first affects the sacroiliac joints and over time may lead to partial or even complete fusion of the backbone, which, of course, causes symptoms.

 You may start noticing stiffness in your SI joints as early as age 15, but generally, the Spondylitis Association says, the onset of the disease occurs between the ages of 17 and 45. 

Because AS isn't usually top of mind as a possible reason for back pain in young people, it is difficult to diagnose in this age group.

In fact, the Spondylitis Association says that AS is the most overlooked cause of persistent back pain in young adults.

Gender and AS

According to the website Physiopedia, AS is a rare disease that has been identified in three times as many men as women.

But Kelly Christal Johnston, a forward-thinking AS patient advocate who lives with the disease, questions the status quo regarding how many, and what type of people get it. 

"Although AS is said to be a mans' disease, I believe that in actuality, it may be pretty evenly distributed among the sexes."  

Johnston explains that for this as well as other reasons, many cases of AS may go undetected in women, making early treatment and effective management more difficult for females.

Research on AS is sorely needed, Johnston informs me.

Michael Smith, another patient advocate who lives with AS disagrees with Johnston. "The facts say that while AS is not exclusively a man's disease, it does primarily affect men. This is a simple citation of the number of reported cases."

And a 2016 epidemiological study focusing specifically on gender and spondylitis backs him up. The study authors reviewed the records of over 2000 patients with AS and found overwhelmingly, it's the males who are affected (73%.)

But as Smith acknowledges, and as the statistic indicates, women are not fully excluded from getting AS. Perhaps more relevant, says the Spondylitis Association of America, is that the severity of AS symptoms is not dependent on gender.

Recent advances in medical technology have enabled the use of MRI for diagnosing AS. Based on this, a group of Canadian researchers wanted know if this new diagnostic capacity has resulted in changes in what we know about the gender make up of those who have (or get) the disease. Their 2014 study analyzed almost 25,000 AS patients to learn more and update their understanding.

The researchers found that proportionally speaking, the number of women with new a diagnosis (i.e., the incidence) of AS is increasing. They say this trend started around the year 2003, and it does correspond with the entry of diagnosis by MRI into the medical landscape.

The authors also comment that males tend to be diagnosed at an earlier age than females, a factor that may contribute to the perception that AS is man's disease. 

So if you're a woman and your doctor has trouble pinpointing the cause of your symptoms, perhaps testing you for things like fibromyalgia or chronic fatigue syndrome, it may not be a bad idea to suggest ankylosing spondylitis as a possible direction.

And you might take heart in the fact that the Spondylitis Association of America was co-founded by a woman, plus the current executive director, as well as the current associate executive director are both women. Women sit on the board in other capacities, too.

AS and Race

Finally, AS can occur in anyone, but it appears to be most common in people of European ancestry.

Living with Ankylosing Spondylitis

Whether or not ankylosing spondylitis strikes your particular demographic, if you have it, you'll likely need to find ways to live with it effectively. It's important to work with a physical therapist to manage your posture and (hopefully) slow the disease's progression. Working with a physical therapist may help you feel more comfortable, as well.

And you might check out Ankylosing Spondylitis Awareness Project on Facebook for support and other sources of helpful information.

 

Sources:

Bakland, G., et. al., Increased mortality in ankylosing spondylitis is related to disease activity. Ann Rheum Dis. Nov 2011. https://www.ncbi.nlm.nih.gov/pubmed/21784726

Helmick, C. et. al. Estimates of the Prevalence of Arthritis and Other Rheumatic Conditions in the United States. Arthritis & Rheumatism. Jan. 2008. http://www.rheumatology.org/about/newsroom/prevalence/prevalence-one.pdf

Masi, A., Savage, L. Integrated Biomechanical Influences on Ankylosing Spondylitis. Spondylitis Association of America website. April 2009. https://web.archive.org/web/20100616015825/http://spondylitis.org/research/pdf/biomechanical_ankylosing_spondylitis.pdf

Landi, M., M.D., et. al. Gender differences among patients with primary ankylosing spondylitis and spondylitis associated with psoriasis and inflammatory bowel disease in an iberoamerican spondyloarthritis cohort. Medicine (Baltimore) Dec. 2016 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5181818/

Reveille JD. Epidemiology of spondyloarthritis in North America. Am J Med Sci. April 2011.

 

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