Weight and Psoriatic Arthritis: Does Body Size Impact PsA Severity?

There are many factors that may impact how severe your psoriatic arthritis is and how well you might respond to treatment. One factor that may influence your psoriatic arthritis course is your weight. For this reason, your rheumatologist may suggest safe and sustainable weight loss as part of your treatment plan.

How does weight affect psoriatic arthritis symptoms?

Psoriatic arthritis can happen to anyone of any body size. That said, people with larger bodies may have a higher risk of more severe symptoms. 

The technical term for fat cells in the body is adipose tissue. This tissue releases inflammatory substances called cytokines. As a result, people who have more adipose tissue are more likely to experience chronic, low-grade inflammation.

Psoriatic arthritis is also an inflammatory condition. During a flare, the immune system is attacking certain parts of the joints, causing inflammation. This creates pain, stiffness, and swelling in the joint. The added inflammation from adipose tissue could worsen the body’s inflammation and lead to more severe symptoms.

How does weight affect psoriatic arthritis treatment?

In studies, people with larger body sizes may not respond as well to biologics and DMARDs (disease-modifying anti-rheumatic drugs) for psoriatic arthritis. This is especially true for a type of DMARD known as TNF inhibitors. These are all common options to treat moderate-to-severe psoriatic arthritis.

One way of measuring treatment effectiveness is called minimal disease activity. This basically means reaching a state where you are having little to no pain, skin symptoms, or disability from your psoriatic arthritis. 

In one 2013 study, participants who had a BMI (body mass index) over 30 were less likely to achieve minimal disease activity. Plus, those who did achieve minimal disease activity were less likely to have sustained it a year later.

Does weight loss help improve psoriatic arthritis?

In one 2014 study, weight loss of 5 percent or higher was associated with better chances of achieving minimal disease activity. Those who lost more than 5 percent had better treatment outcomes than those who lost less than 5 percent.

Keep in mind that losing weight doesn’t guarantee that psoriatic arthritis symptoms and treatment outcomes will improve. There are many factors that may contribute to disease severity.

What does safe and sustainable weight loss look like?

Losing weight can be difficult, and there is a lot of untrustworthy information about how to lose weight. Certain “diet tricks” may result in rapid weight loss, but they can also lead to yo-yo dieting (or “weight cycling”). This can have negative effects on your overall health in the long run.

Safe and sustainable weight loss takes time and consistency. A reasonable goal is to lose 5 to 10 percent of your starting body weight in six months. In general, this may look like losing one to two pounds a week. Losing weight more rapidly than this may be unsafe and unsustainable.

Working with a registered dietitian or other healthcare professional may help you make effective lifestyle changes that may aid in weight loss.

Can I still get psoriatic arthritis treatment even if I don’t lose weight?

Regardless of your body size, your rheumatologist should work with you to find the most effective treatment plan. If you feel like anyone on your care team is discriminating against you due to your weight, it may be worthwhile to make adjustments to your healthcare team. You could also try raising the issue with a trusted member of the care team. 

While weight loss may generally help your psoriatic arthritis, it should not be a requirement to receive the healthcare you deserve.