Relationship between polyautoimmunity and sarcopenic obesity in rheumatoid arthritis patients

OBJECTIVE

Sarcopenia is a major cause of morbidity in rheumatoid arthritis patients. Our purpose was to determine whether polyautoimmunity is associated with sarcopenia and alterations in whole body composition in patients with rheumatoid arthritis (RA).

METHODS

We performed a cross-sectional observational study of a series of cases of RA. All patients were recruited consecutively from a rheumatology clinic. Body composition by dual-energy x-ray absorptiometry (DEXA) was assessed. The variables of interest were polyautoimmunity (RA associated with other autoimmune diseases), sarcopenia, fat mass, and body mass index (BMI). Other variables included were clinical-analytical and inflammatory cytokines and adipokines. The relationship between sarcopenic obesity and the presence of polyautoimmunity was studied using multivariate analysis.

RESULTS

Of the 94 patients with RA included in the study, 15 (16%) had polyautoimmunity. A total of 23 patients with RA (24.5%) had sarcopenia, which was more prevalent in patients with polyautoimmunity than in patients without polyautoimmunity (46.7% vs 20.3%; p = .029). Sarcopenia was not associated with body fat content (p = .870) or with BMI (p = .998). The multivariate analysis showed the factors associated with polyautoimmunity in RA to be sarcopenia (odds ratio [95% CI], 4.80 [1.49-13.95]), BMI (1.18 [1.04-1.35]), and resistin (1.249 [1.01-1.53]).

CONCLUSION

Sarcopenia and obesity were more prevalent in patients with RA and polyautoimmunity. Resistin values were also higher in this group than in patients with RA without polyautoimmunity.

Coexistence of Systemic Lupus Erythematosus and Myasthenia Gravis: An Unusual Case of Polyautoimmunity

The relevance of polyautoimmunity, defined as the presence of 2or more autoimmune diseases in the same individual, is one of the issues not yet elucidated in medical practice. The coexistence of myasthenia gravis (MG) and systemic lupus erythematosus (SLE) is a clinical challenge due to the possible differential diagnoses of muscle involvement in patients with SLE. We present the case of a patient who came to the emergency room of Hospital Universitario San Ignacio in Bogotá, Colombia, with a previous diagnosis of SLE, who developed acute weakness in the context of a systemic infection, with a clinical and electrophysiological diagnosis of MG.