Men with rheumatoid arthritis have a two-thirds greater risk of developing erectile dysfunction than men without the disease, based on the results of the first study to show such an association.
The odds ratio for prior rheumatoid arthritis (RA) among men with erectile dysfunction (ED) was 1.67 that of controls, based on conditional logistic regression analysis, after adjusting for the possible confounding effects of monthly income, geographical location, urbanization level, hypertension, diabetes, coronary heart disease, hyperlipidemia, obesity, and alcohol abuse/alcohol dependence syndrome. The study was published in a letter in Annals of the Rheumatic Diseases on Jan. 4 (Ann. Rheum. Dis. 2011 Jan. 4 [doi:10.1136/annrheumdis-2011-200890]).
"This study succeeded in making a novel association between ED and prior RA. It is important for physicians treating RA patients to be sensitive to any complaints concerning sexual function and consider referring them for an erectile function assessment and possible treatment," wrote Dr. Joseph J Keller and Herng-Ching Lin, Ph.D., of the Taipei (Taiwan) Medical University.
The study included 6,310 patients (aged 18-80 years) who had received a first-time diagnosis of ED between 2001 and 2009 as cases and 37,860 control patients (six controls per case) were matched with cases in terms of age (in intervals of 10 years) and index year.
"It is important for physicians treating RA patients to be sensitive to any complaints concerning sexual function."
The researchers used administrative claims data from the Taiwan Longitudinal Health Insurance Database 2000 for this study. The database includes all the claims data and registration files of 1 million individuals under the Taiwan National Health Insurance program.
The researchers included only ED patients who had been diagnosed at least twice during the period between 2001 and 2009 – with at least one of the diagnoses being made by a urologist – in order to increase the diagnostic validity of ED.
The researchers also selected patients with RA who had received two or more RA diagnoses prior to the index date – with at least one being made by a rheumatologist. In addition, RA cases were included only if they had been prescribed at least one type of disease-modifying antirheumatic drug.
It has been suggested that patients with RA may be more likely to develop other conditions – such as ED – that are associated with increased cardiovascular risks and chronic inflammation. However, no study has explored the possible association between ED and RA to date.
The researchers noted that "it is possible that the association seen in this study between RA and ED proceeds through RA-induced endothelial dysfunction. Although a plethora of mechanisms have been proposed to underpin ED’s association with other diseases. ... [F]urther studies will be necessary to explore the mechanistic underpinnings of the association detected in this study."
Both authors reported that they have no competing interests.