Research suggests that people with allergic asthma or eczema are at increased risk for osteoarthritis compared with those without allergies.
Osteoarthritis is the most common type of arthritis, impacting approximately one in seven adults in the U.S. “Osteoarthritis is associated with considerable morbidity—it is one of the major contributors to the global years lived with disability and the principal cause of lower extremity disability in older adults,” write Matthew Baker, an assistant professor of medicine at Stanford University, and colleagues in the Annals of the Rheumatic Diseases.
“Despite the high prevalence, substantial economic burden and debilitating impact of osteoarthritis, the current therapeutic armamentarium is limited and focuses on symptom management.”
Previously thought to be a result of ‘wear and tear’ and aging, there is now increasing data that inflammation plays a significant role in this condition. “Mounting evidence suggests that mast cell activation and allergic pathways may play key roles in osteoarthritis pathogenesis,” write Baker and team.
Following the hypothesis that if mast cells are involved in osteoarthritis, then people with a history of allergies may be at increased risk for the condition, first-author Baker and colleagues carried out a study of insurance claims data in the U.S. The study group included 117,346 people with allergic asthma or eczema (average age 52 years, 60% women) and 1,247,196 without these conditions (aged 50 on average, 48% women) who did not initially have osteoarthritis.
By combining health records data with insurance claims data, the researchers were able to calculate the risks of developing osteoarthritis over an average follow-up time of 8 years.
Patients with asthma or eczema were 58% more likely to develop osteoarthritis during the follow-up period than those with neither condition, after adjusting for potential confounding factors. Individuals with both asthma and eczema had a 2.15-fold increased risk compared to those without allergies.
Notably, patients with asthma had an 83% increased risk for osteoarthritis compared with chronic obstructive pulmonary disease patients.
Baker and team replicated their results in a separate cohort of patients, the Stanford Research Repository, and the association was confirmed. Patients with asthma or eczema in this group had a 42% increased risk for osteoarthritis compared with non-allergic controls, although with a weaker (but still significant) association than the initial cohort after obesity was accounted for.
“The association between atopic disease and osteoarthritis is supported by recent observations that mast cells and type II cytokines may play important roles in the pathogenesis of osteoarthritis broadly, not just in patients with atopic disease,” conclude the authors.
“Our findings provide further support for the concept that allergic pathways may contribute to the development of osteoarthritis. If this is indeed true, non-atopic patients may also benefit from the use of treatments that inhibit mast cells and allergic cytokines to treat or prevent osteoarthritis.”
