People with psoriatic arthritis (PsA) and those with severe psoriasis are at higher risk than the general population for a type of fracture typically associated with osteoporosis, according to a new study published online in January 2017 in Annals of the Rheumatic Diseases. In fact, the increase in risk for these two groups is comparable or even higher than that of people with rheumatoid arthritis (RA), a group known to have higher than average risks of osteoporosis and fracture related to low bone mineral density.
This is the first study to estimate the risk for a first fracture in patients with psoriasis and PsA , the authors say.
Researchers analyzed data from The Health Improvement Network (THIN) in the United Kingdom from 1994 to January 2014. In total, 9,788 people with PsA, 158,323 people with psoriasis, 39,306 with RA and 821,834 people with no disease (matched controls) were identified. The people with psoriasis were further classified as having mild or severe disease according to the type of treatment they received for their psoriasis. People with a history of fracture or osteoporosis were excluded from this analysis.
Looking at data from the participants’ doctor visits over time, the researchers noted when anyone had a hip fracture, vertebral (spine) fracture, or “any” fracture. They also looked for factors that affect osteoporosis risk, such as age, sex, body mass index, menopausal status, smoking, alcohol use, the use of certain medications, and the presence of particular other diseases including diabetes and depression.
Osteoporosis Risk Factors
Participants with PsA and/or psoriasis were found to have more risk factors for osteoporosis – including diabetes, depression, heavy alcohol use, smoking and the use of certain medications – than those without PsA or psoriasis. Researchers also found that, even after taking into account these osteoporosis risk factors, PsA patients had a 16 percent increased risk of fracture compared to controls, patients with mild psoriasis had a 7 percent increased risk and those with severe psoriasis had a 26 percent increased risk. In comparison, people with RA had a 23 percent increased risk of fracture.
Lead study author Alexis Ogdie, MD, assistant professor of medicine and director of the Penn Psoriatic Arthritis Clinic at the University of Pennsylvania, in Philadelphia, says that the information in THIN database did not allow them to specifically analyze fracture risk for people with PsA who also had severe psoriasis.
“We would hypothesize that if a person has PsA with severe skin disease, their risk would be at least as high as the higher one,” she says. “Severe psoriasis had a higher risk than psoriatic arthritis in our study so it’s probably at least that high, and there could be an additive component, but we don’t know that.”
Dafna D. Gladman, MD, professor of medicine at the University of Toronto and the deputy director at Centre for Prognosis Studies in The Rheumatic Diseases, says one of the major strengths of the study is that it involved a very large number of individuals.
But she notes that Dr. Ogdie couldn’t figure out relationships between disease specifics – like arthritis severity or presence of nail changes – and fracture risk. “The limitations are that there is not a lot of information related to the disease process in these databases and there are limitations on what they can study in terms of correlations and associations with disease features,” she says.
“The major message here is that there is an increased risk for fracture in people with PsA and psoriasis,” Dr. Ogdie says, “so we need to be doing what we would do for the general population, which is screening with DEXA scans [a type of X-ray that measures bone loss] and teaching them about protective measures.”
Dr. Gladman urges people with PsA to make sure disease-related inflammation is under control. Additionally, she advises, don’t smoke, perform weight-bearing exercise when possible, drink alcohol only in moderation, get plenty of calcium and vitamin D, and ask if you should be taking medications to improve bone mineral density.
Author: Beth Axtell for the Arthritis Foundation