Background Arthritis is one of the most common chronic conditions affecting 4.6 million Canadians. It is also the most common cause of disability between the ages of 40 and 70 years. Arthritis and its comorbidities exert profound stresses on the health care system in both personal and economic terms (PHAC 2011).
Objectives To compare the prevalence of comorbidities in patients with Early Rheumatoid Arthritis (ERA) and Early Psoriatic Arthritis (EPsA).
Methods Patients diagnosed with ERA and EPsA (defined as <2 years from the onset of symptoms) were included in the cohorts. Demographic data, clinical characteristics and the prevalence of comorbid conditions were compared between cohorts using descriptive, chi-square and t-test statistics.
Results A total of 184 patients (100 with ERA and 84 with EPsA) were prospectively enrolled in the study and completed at least 24 months of observation. Patients within the ERA cohort had a significantly higher proportion of females (83% vs. 52.4%; P<0.001). Patients with ERA had moderate/high disease activity compared to low/moderate in EPsA patients with the higher average values of inflammatory markers and HAQ.
Thirty-one comorbidities were identified; 99% of patients with EPsA and 95% with ERA had at least one comorbidity with the maximum 11 and 10 of them per person, respectively. 54.8% of EPsA and 34% of ERA patients had 4 or more comorbidities with their similar distribution between genders. The most prevalent were: Musculoskeletal (apart from RA or PsA), Obesity, Gastrointestinal diseases, Hypertension, and Diabetes with similar distribution between cohorts. 12% of ERA patients had PSO (PASI 2.0 (3.0). The history of 10 different malignancies was ascertained. There was only significant difference in the prevalence of cervical dysplasia/cancer among females with ERA (13% vs. 1.2%, p<0.001). The 10-year Framingham CV risk was comparable among patients in both groups (ERA 12.1 (9.3) vs. EPsA 11.3 (8.1)) and strongly correlated with the conventional risk factors. Risk of cardiovascular event in patients with EPsA was also significantly correlated with age of onset of PSO (r=0.535, p<0.001) and PsA (r=0.708, p<0.001), polyarticular joint involvement (r=0.261, p=0.017) and total number of comorbidities (r=0.375, p<0.001); while in patients with ERA the same risk was correlated with the age of RA onset (r=0.730, p<0.001), co-existing musculoskeletal conditions (r=0.293, p=0.003), and total number of comorbidities (r=0.575, p<0.001). The majority of patients with ERA (89% vs. 49%) were treated by MTX with earlier initiation of biologics.
Conclusions Comorbidities are very common conditions in patients with arthritis even at the early stages of disease. Patients with EPsA have a greater number of comorbidities per person than ERA patients. The comorbidities affected by arthritis activity may in turn lead to more or earlier disability. Cardiovascular risk was clear at an early stage of both cohorts and warrants enhanced intervention strategies to prevent morbidity and mortality in RA and PsA.
Disclosure of Interest None declared