The frequency at which rheumatoid arthritis (RA) is accompanied by comorbid conditions such as hypertension or diabetes is often higher than might be expected, an observation that researchers say should be remembered when designing disease management strategies.
Outlining the reasons for the current study, the authors explain that "a better characterization of multi-morbid patients with rheumatic diseases would help rheumatologists in their evaluation in daily practice, as well as health authorities in decision-making progress.
"In addition, determining which specific combinations of diseases are more prevalent than expected may help to generate hypotheses on common ethiopathogenesis, an issue that was known previously in epidemiology but that is arising from genome-wide scan studies where gene polymorphisms are found to be shared among various diseases," the investigators add.
Accordingly, Loreto Carmona (Fundación Española de Reumatología, Madrid, Spain) and co-workers studied self-reported data on chronic conditions among 2192 randomly selected members of the general Spanish population.
Statistical evaluation revealed that arterial hypertension, Type 2 diabetes, hypercholesterolemia, cardiovascular disease, and digestive disease all occurred at higher than expected prevalence in patients with RA, giving observed to expected prevalence ratios of 1.88, 2.07, 1.87, 1.83, and 2.07, respectively.
Carmona et al note that, in younger individuals, the higher than expected prevalence of comorbidities could be at least partially attributed to the presence of RA, whereas in older individuals, who suffered comorbidities more frequently, conditions might be occurring by chance.
Concluding in the Annals of the Rheumatic Diseases, the authors suggest that the statistical methods used in the current study might be used in future work to determine whether the links between RA and the comorbidities described here are co-incidental or causal.