Prevalence and correlates of metabolic syndrome in patients with rheumatoid arthritis in Argentina

Abstract

Background: The increased mortality reported among patient with rheumatoid arthritis (RA) has been attributed to cardiovascular disease. Metabolic syndrome (MS) is a cluster of major risk factors for cardiovascular disease such as dyslipidemia, obesity, hypertension, and diabetes. There is a lack of reporting on the prevalence of MS in RA patients in Argentina.

Objectives: The objectives of this study were to determine and compare the frequency of MS in patients with RA and a control group and to assess the factors associated with MS.

Methods: This is a cross-sectional study involving 1033 (409 RA and 624 age- and sex-matched control subjects) patients, followed up at 9 different rheumatology units in Argentina. Metabolic syndrome was defined according to the Adult Treatment Panel III (ATP III) and the International Diabetes Federation (IDF). The relationship between demographic variables, clinical data (disease duration, disease activity by Disease Activity Score of 28 joints, presence of rheumatoid factor [RF] and/or anti-cyclic citrullinated peptide antibody, presence of extra-articular manifestations), pharmacological treatment, and MS was examined by descriptive statistics. Variables with P ≤ 0.10 in these analyses were then examined by logistic regression.

Results: The frequency of MS in RA patients and the control group was 30% versus 39% (P = 0.002) when defined as per the ATP III and 35% versus 40% (P = 0.10) as per the IDF. Variables independently associated with MS in RA patients were age (odds ratio [OR], 1.03; 95% confidence interval [CI], 1.01-1.06 [P = 0.01] for the ATP III and OR, 1.03; 95% CI, 1.01-1.05 [P < 0.001] for the IDF), the presence of RF and/or anti-cyclic citrullinated peptide antibody (OR, 2.91; 95% CI, 1.11-7.61 [P = 0.02] for the ATP III and OR, 2.37; 95% CI, 1.09-5.16 [P = 0.02] for the IDF), and the use of hydroxychloroquine (OR, 0.48; 95% CI, 0.23-0.97 [P = 0.04] only for the IDF).

Conclusions: In this study, we were not able to demonstrate a higher frequency of MS in RA patients. However, older patients with positive RF or CCP have a higher risk of MS. A protective effect to develop MS was seen in the population treated with hydroxychloroquine.