The impact of cardiorespiratory fitness on classical cardiovascular disease risk factors in rheumatoid arthritis: a cross-sectional and longitudinal study.

Rheumatoid arthritis (RA) is associated with an increased risk of cardiovascular disease (CVD). Advanced measures of cardiorespiratory fitness (CRF) are associated with CVD risk factors. The present study aimed to examine whether CVD risk factors can predict clinic-based measures of CRF, using the Siconolfi step test and to determine if exercise can improve RA patients' cardiovascular health. Sixty-five RA patients (46 females, age 58 ± 11 years) completed assessments of CRF, CVD risk factors, body composition and RA characteristics. Ten patients participated in a follow-up 8-week exercise intervention. CRF was low (22 ml kg-1 min-1) and associated with higher diastolic blood pressure (r = - 0.37, p = 0.002), higher global CVD risk (r = - 0.267, p = 0.031) and worse body composition profile (body fat, r = - 0.48, p < 0.001; waist, r = - 0.65, p < 0.001; hip, r = - 0.58, p < 0.001). Regular exercise significantly improved CRF (p = 0.021), lower body strength (p < 0.001), agility (p < 0.001), systolic blood pressure (p = 0.021), body fat (p = 0.018), waist circumference (p = 0.035), hip circumference (p = 0.016), disease activity (p = 0.002), disability (p = 0.007) and QoL (p = 0.004). Elevated diastolic blood pressure and worse body composition profile are strong predictors of clinic-based measures of CRF. CRF is an important determinant of CVD risk and warrants inclusion in the routine assessment of RA patients. Regular exercise can improve CRF and CVD risk factors without any exacerbation of disease activity and should be offered as part of routine care.

Prediction of cardiovascular risk in rheumatoid arthritis: performance of original and adapted SCORE algorithms.

OBJECTIVES: Predictive performance of cardiovascular disease (CVD) risk calculators appears suboptimal in rheumatoid arthritis (RA). A disease-specific CVD risk algorithm may improve CVD risk prediction in RA. The objectives of this study are to adapt the Systematic COronary Risk Evaluation (SCORE) algorithm with determinants of CVD risk in RA and to assess the accuracy of CVD risk prediction calculated with the adapted SCORE algorithm. METHODS: Data from the Nijmegen early RA inception cohort were used. The primary outcome was first CVD events. The SCORE algorithm was recalibrated by reweighing included traditional CVD risk factors and adapted by adding other potential predictors of CVD. Predictive performance of the recalibrated and adapted SCORE algorithms was assessed and the adapted SCORE was externally validated. RESULTS: Of the 1016 included patients with RA, 103 patients experienced a CVD event. Discriminatory ability was comparable across the original, recalibrated and adapted SCORE algorithms. The Hosmer-Lemeshow test results indicated that all three algorithms provided poor model fit (p<0.05) for the Nijmegen and external validation cohort. The adapted SCORE algorithm mainly improves CVD risk estimation in non-event cases and does not show a clear advantage in reclassifying patients with RA who develop CVD (event cases) into more appropriate risk groups. CONCLUSIONS: This study demonstrates for the first time that adaptations of the SCORE algorithm do not provide sufficient improvement in risk prediction of future CVD in RA to serve as an appropriate alternative to the original SCORE. Risk assessment using the original SCORE algorithm may underestimate CVD risk in patients with RA.

Associations between asymmetric dimethylarginine, homocysteine, and the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism (rs1801133) in rheumatoid arthritis.

OBJECTIVES: The aim of our study was to determine whether asymmetric dimethylarginine (ADMA) levels are associated with homocysteine (Hcy) and methylenetetrahydrofolate reductase (MTHFR) C677T (rs1801133) gene variants in patients with rheumatoid arthritis (RA). METHOD: Serum ADMA and Hcy levels were measured in 201 RA individuals [155 (77.1%) females, median age 67 years (interquartile range 59-73)]. The MTHFR C677T polymorphism was assessed by using the LightCyclerTM System. Initially, ADMA was compared across the categories of MTHFR using a one-way analysis of variance (ANOVA), followed by a multivariate model, which accounted for Hcy, age, erythrocyte sedimentation rate (ESR), and homeostatic model assessment (HOMA). RESULTS: In univariable analysis, ADMA differed significantly across the categories of MTHFR (p = 0.037). Patients with the MTHFR 677TT genotype had the highest ADMA levels, with a mean of 0.62 (SE = 0.03), significantly higher than either those patients carrying the MTHFR 677CT (0.55, SE = 0.01) or the MTHFR 677CC (0.55, SE = 0.01) genotype (p = 0.042) in both cases. In the multivariable model, Hcy (p = 0.022) and ESR (p < 0.001) were found to have significant positive associations with ADMA but the relationship between MTHFR gene variants and ADMA was found to be non-significant (p = 0.102). CONCLUSIONS: Hcy and ADMA are significantly associated in RA. It is plausible that abnormal Hcy metabolism plays an important role in premature atherosclerosis in RA by promoting ADMA accumulation and leading to the derangement of vascular haemostasis.

Predictors of asymmetric dimethylarginine levels in patients with rheumatoid arthritis: the role of insulin resistance.

OBJECTIVE: To determine whether demographic, inflammatory, and metabolic factors predict elevated asymmetric dimethylarginine (ADMA) levels in rheumatoid arthritis (RA). METHOD: A total of 67 RA patients [mean age 56 ± 12 years, median disease duration 8 (3-15) years] were assessed. Routine biochemistry tests, lipid profile, glycaemic profile [glucose, insulin, homeostasis model assessment (HOMA), quantitative insulin sensitivity check index (QUICKI)], and inflammatory markers were measured in all patients. ADMA levels were measured by enzyme-linked immunosorbent assay (ELISA). Regression analyses were performed to identify predictors of ADMA in RA. RESULTS: Regression analysis revealed that HOMA (ß = 0.149, p = 0.003) was an independent predictor of ADMA in RA. From the drug factors, anti-hypertensive medication use was associated with lower ADMA levels (ß = -0.081, p = 0.004). ADMA was not associated with RA disease-related parameters or any of the other cardiovascular risk factors that were assessed. CONCLUSIONS: HOMA, a strong indicator of insulin resistance, seems to be the main predictor of elevated ADMA levels in RA patients; ADMA may reflect an important pathway linking abnormal insulin metabolism with endothelial dysfunction in RA.

Lack of association between asymmetric dimethylarginine and in vivo microvascular and macrovascular endothelial function in patients with rheumatoid arthritis.

OBJECTIVES: The aim of the present study was to investigate if assymetric dimethylarginine (ADMA) is increased in patients with rheumatoid arthritis (RA) compared to healthy controls and to examine associations between ADMA, RA disease activity and in vivo assessments of microvascular and macrovascular endothelial function. METHODS: Sixty-seven RA patients (age [mean ± standard deviation]: 56 ± 12 years, disease duration median [25th-75th percentile]: 8 [3-15] years, 48 women) and 29 healthy controls (age [mean ± standard deviation]: 42 ± 12, 21 women) underwent assessments of microvascular endothelial function (Laser Doppler imaging with iontophoresis of acetylcholine and sodium-nitroprusside), and macrovascular endothelial function (flow-mediated dilatation and glyceryl-trinitrate-mediated dilatation) as well as arterial stiffness. ADMA levels were measured in contemporary specimens using an immunoassay ELISA kit. RESULTS: ADMA levels were significantly higher (p=0.004) in RA patients compared with healthy controls after adjustment for age (difference=0.088, 95% confidence interval 0.029-0.147). ADMA levels did not correlate with demographic or disease characteristics. No correlation was found between ADMA and microvascular and macrovascular endothelial function or with arterial stiffness. CONCLUSIONS: ADMA levels are increased in patients with RA but there was no significant correlation with in vivo assessments of endothelial function. Further studies are needed to unfold the pathophysiological role of nitric oxide/ADMA pathway derangement in endothelial dysfunction and cardiovascular risk in RA.

Rheumatoid cachexia and cardiovascular disease.

OBJECTIVE: It has been frequently stated that rheumatoid cachexia (RC) associates with increased cardiovascular risk; however, no studies to date have investigated this. The aim of this study was to investigate the association of RC with multiple novel and classical cardiovascular disease (CVD) risk factors and the presence of established CVD in rheumatoid arthritis (RA). METHODS: A total of 34 RA patients with RC (RA+RC) were identified from a database of 400 RA patients using published RC criteria and compared to the remaining patients (RA-RC) who did not fulfil RC criteria. All patients were assessed for fat and fat-free mass, albumin (indicator of catabolism), disease activity/severity, novel and classical risk CVD factors and established CVD. RESULTS: Fat-free mass (kg) and albumin (g/L) were significantly decreased in RA+RC vs. RA-RC patients: 37.3(33.9-41.6) vs. 45.9(41.2-55.5), p<0.001 and 39.6 + or - 6.7 vs. 42.4 + or - 4.9, p=0.001). Percent body fat was not significantly different. No significant differences were detected in either the classical or novel CVD risk factors, 10-year CVD risk or the prevalence of established CVD. CONCLUSIONS: RC does not appear to be associated with worse CVD profile in RA patients, but this needs to be confirmed in prospective studies.