Metabolic syndrome in rheumatoid arthritis: role of adiponectin (preliminary results)

Abstract

The clinical value of the disorders and diseases integrated within the metabolic syndrome (MS) is in the combination of traditional risk factors for cardiovascular diseases (CVD), which significantly accelerates the development of cardiovascular events (CVEs). The detection rate for MS in patients with rheumatoid arthritis (RA) is shown to be higher than in the controls regardless of the diagnostic criteria for MS. At present, there are confusing data on the role of adipokins in RA. Objective: to determine the rate of MS and its components in RA patients and the association of the level of adipokin (adiponectin) with the components of MS in relation to the duration of RA. Subjects and methods: The investigation enrolled 69 RA patients divided into two groups: 1) 34 patients with early-stage (<2-year) RA and 2) 35 patients with end-stage (>2-year) RA. Results. MS occurred in 12 (17.4%) of the 69 patients with RA. There was central (abdominal) obesity in 37 (53.6%) patients with RA, hypertension in 29 (42%), low high-density cholesterol levels in 20 (29%), hyperglycemia in 11 (15.9%), and hypertriglyceridemia in 10 (14.5%). According to the presence or absence of MS, the patients were divided into 2 groups: 1) 12 patients with MS; 2) 57 without MS. In the patients with RA and MS, the duration of the disease was shorter; DAS28 and CDAI were higher than in those without MS: 15.4 [7; 24] months versus 51.8 [6; 72] months; DAS28 was 5.8 [4.9; 6.7] scores versus 5.1 [4.5; 5.8] scores; CDAI: 34.8 [21.8; 41.4] scores versus 24.2 [18; 31] scores, respectively (p < 0.05 in all cases). The serum level of adiponectin was lower: 13.1 [5.7; 10.7] ng/ml versus 20.6 [6.9; 30.9] ng/ml in the patients with RA and MS as compared to those without MS; but there were no significant differences. In the patients with early-end RA, the rate of MS was twice higher than that in those with end-stage RA; however, the differences were statistically insignificant (p = 0.1). The components of MS were encountered with the same frequency in early- and end-stage RA. The early RA group showed a correlation between SDAI (r = -0.34), body mass index (r = -0.41), high-density lipoprotein cholesterol (r = 0.33), erythrocyte sedimentation rate (r =-0.35), and adiponectin. The >2-year RA group displayed no relationship between adipokins, activity markers, and metabolic disturbances. Conclusion. The preliminary results suggest the high rate of MS in patients with a high level of early RA disease activity untreated with disease-modifying antirheumatic drugs, thus determining the high risk of CVEs just at disease onset. The role of adiponectin in the development of MS, CVEs in rheumatic diseases remains to be solved, which is the subject of further investigations. It is possible that normalization of adiponectin concentrations may promote reductions in the incidence of CVD, mortality rates due to atherosclerosis-induced CVEs, and the prevalence of MS and insulin resistance.

Keywords

• metabolic syndrome
• rheumatoid arthritis
• adiponectin
• cardiovascular events