Background/Purpose:
Rheumatoid arthritis
(RA), psoriatic arthritis (PsA), ankylosing spondylitis (AS) and systemic lupus
erythematosus (SLE) are immune-mediated disorders and are associated with a
number of comorbidities, including cardiovascular disease.  However, reported rates
may depend on study design, control population and exposure data. The aim of
this study was to assess the rate of comorbidities in patients with RA, PsA, AS
and SLE compared to the general population without these rheumatological
conditions using data from a large national study.

Methods:
This study was
conducted using UK Biobank data from over 500,000 people aged 40-70 years in
the UK. At entry, participants completed a touchscreen questionnaire on
lifestyle, sociodemographics, and health and medical history, followed by a
verbal interview with a research nurse. Health history questions captured the
occurrence of cardiovascular, pulmonary, allergic and metabolic comorbidities
(Table 2). Patients reporting non-specific arthritis were excluded from the total
population. Indirect standardization was used to adjust the comorbidity prevalence
rates in each of the four rheumatological populations separately (i.e. RA, PsA,
AS, SLE) using the age and gender rates in the population without these
conditions. The Standardized Incidence Ratios (SIR) were estimated by dividing
the observed number of comorbidity events by the “expected” number of events.

Results:
498,611 participants
were included in this study, cohort characteristics are summarised in Table 1. The
incidence rates of all cardiovascular diseases were significantly higher in the
RA and SLE population compared to the general population. Although not significant,
similar trends were observed for the AS and PsA population. Rates of allergies
were similar between the populations with rheumatological conditions and those
observed in the general population without these conditions. Moreover, the
incidence rate of emphysema was significantly higher in all populations with
rheumatological compared to the general population. Finally, the rate of
diabetes in RA patients was higher compared to the general population. However,
this was not observed in the other rheumatological conditions (Table 2).

Conclusion:
In this
cross-sectional study, prevalence rates of cardiovascular diseases and lung
disorders are especially increased in people with RA, AS and SLE. This study is unique in that it
captures morbidities in a similar way across several rheumatic conditions in a
large national-based study.

 Table 1

 Table 2