Patients with inflammatory arthritis (IA) frequently also have other chronic medical conditions. These may preceed or follow after the diagnosis of IA. From the patient's perspective their IA may not be the most important of these medical conditions and, acknowledging this, it is better to refer to multimorbidity rather than co-morbidity.
Some chronic medical conditions occur more frequently in IA than the general population. This may reflect the genetic and environmental risk factors for IA which, by definition, occur more frequently in IA patients than in the general population. Examples include smoking related illnesses such as chronic obstructive pulmonary disease and lung cancer; and other auto-immune conditions.
After IA onset, the inflammatory disease process may predispose to other medical conditions such as coronary heart disease (CHD) and peripheral vascular disease. Immunosuppressant treatment may lead to patients being more susceptible to infection and certain types of cancer. Steroid therapy is associated with a wide range of co-morbid conditions including diabetes, hypertension and obesity.
Treatment of IA is inevitably more difficult in the presence of other medical conditions. The treatment of IA may exacerbate a co-morbid condition. For example some of the drugs used (NSAIDs, leflunomide, ciclosporin, steroids) may make hypertension more difficult to control. Many anti-rheumatic drugs are associated with an increased risk of infection which may be particularly problematic in patients with chronic lung disease. Thus patients with multi-morbidity tend to have more severe IA because it is more challenging to control disease activity and also for the patients to maintain their physical activity and general fitness.
Nevertheless the imperative to achieve disease remission is often greater in patients with multimorbidity. There is evidence that the increased prevalence of CHD in IA is related to cumulative disease activity - and so complete suppression of disease activity will reduce the patient's risk of CHD as well as benefitting the joints. Stopping smoking will not only help the patient's chest and heart, but also increase their likelihood of responding to certain anti-rheumatic drugs.
The patient needs to receive consistent advice and not to attend multiple clinics for their conditions if this is possible; hence the importance of multidisciplinary clinics and a holistic approach to management.
Disclosure of Interest None declared