Objective: To identify factors that regulate glucose metabolism in rheumatoid arthritis (RA).Methods: We evaluated the homeostatic model assessment of insulin resistance (HOMA‐IR) and beta cell function (HOMA‐B) in 94 RA patients. We investigated the relationship between characteristics known to affect glucose metabolism in the general population (age, abdominal obesity [waist circumference], hypertension, antihypertensive therapy) as well as characteristics of RA (disease activity, glucocorticoid therapy) and insulin resistance and beta cell function.Results: Patients with high‐grade inflammation (high‐sensitivity C‐reactive protein value >1.92 mg/liter) (n = 81) were more insulin resistant than patients with low‐grade inflammation (n = 13), whereas beta cell function was similar in both groups. Insulin resistance and beta cell function were similar in both groups after adjustment for waist circumference. All recorded characteristics except for age were associated with HOMA‐IR or/and HOMA‐B in univariate analyses. In mixed regression models, abdominal obesity and patient's assessment of disease activity (by visual analog scale) were predictors of insulin resistance. The Disease Activity Score assessed using 28‐joint counts for swelling and tenderness, tender joint count, and patient's assessment of disease activity were associated with reduced beta cell function, and the cumulative dose of glucocorticoids was associated with enhanced beta cell function. The cumulative glucocorticoid dose in all study patients was a mean of only 536 mg (95% confidence interval 239–1,173). In patients with high‐grade inflammation, age was further associated with impaired beta cell function, whereas use of angiotensin‐converting enzyme inhibitors or angiotensin II type 1 receptor blockers was associated with enhanced beta cell function.Conclusion: The modifiable factors of abdominal obesity, antihypertensive therapy, disease activity, and use of glucocorticoids appear to affect glucose metabolism in RA.

Objective.: Depending on physiological context, the adipokine chemerin can reduce or enhance cardiovascular risk. We investigated whether chemerin concentrations represent cardiovascular disease risk in rheumatoid arthritis (RA).Methods.: We assessed ELISA-determined chemerin concentrations and those of 4 early endothelial activation molecules as well as angiopoietin 2, which mediates angiogenesis and thereby contributes to advanced atherosclerosis, the common carotid artery intima-media thickness (cIMT), and carotid artery plaque by ultrasound in 236 patients (114 black and 122 white) with RA. Relationships were identified in potential confounder and mediator-adjusted mixed regression models.Results.: Mean (SD) chemerin and median (interquartile range) angiopoietin 2 concentrations were 114 (35) ng/ml and 2560 (2044–3341) pg/ml, respectively; the mean (SD) cIMT was 0.708 (0.110) mm, and 40.3% of patients had plaque. Chemerin concentrations were not related to those of early endothelial activation molecules, but associated with those of angiopoietin 2 [β SE = 0.002 (0.0004), p < 0.0001] and plaque [OR 1.006 (95% CI 1.00–1.013), p = 0.05] in all patients. The presence of major conventional cardiovascular risk factors, generalized and abdominal obesity, and RA severity markers modified the independent chemerin-cardiovascular risk relations (interaction p < 0.05). Consequently, chemerin concentrations were associated with cIMT in those with but not without overweight or generalized obesity and abdominal obesity [β SE = 0.001 (0.0003), p = 0.005 and 0.001 (0.0001), p = 0.001 vs −0.001 (0.0004), p = 0.2 and −0.0002 (0.0004), p = 0.6, respectively], and with plaque in those without but not with generalized obesity [OR 1.008 (95% CI) 1.000–1.016, p = 0.03 vs 1.003 (0.990–1.017), p = 0.6, respectively]. The β (SE) for the chemerin-intima-media thickness relations in patients with overweight or generalized obesity and abdominal obesity were larger than in those without these characteristics (p < 0.0001 and = 0.04, respectively).Conclusion.: Chemerin is associated with endothelial activation and atherosclerosis in RA. Adiposity influences the chemerin-atherosclerotic phenotype relations in RA.

Objective.: Osteoprotegerin (OPG) may contribute to the link between systemic inflammation and increased cardiovascular risk. We investigated the relationship of OPG concentrations with endothelial activation and carotid atherosclerosis in rheumatoid arthritis (RA).Methods.: OPG concentrations and those of endothelial activation molecules were measured by using ELISA in 34 patients who were treated with infliximab (IFX), both immediately before and after an IFX infusion. Carotid intima-media thickness (CIMT) and plaque were determined by ultrasound in 27 of the study participants.Results.: Median (interquartile range) OPG concentrations decreased from 4.8 pmol/l (2.8–6.5) to 4.4 pmol/l (2.9–6.1; p = 0.04) upon IFX infusion. Baseline OPG concentrations were inversely associated with those of total and low-density lipoprotein (LDL) cholesterol (partial R = −0.50, p = 0.004, and R = −0.48, p = 0.007, respectively). Prior to IFX administration, OPG concentrations were associated with those of intercellular adhesion molecule (ICAM)-1 (partial R = 0.34, p = 0.05), CIMT (partial R = 0.51 to 0.52, p < 0.009), and plaque (OR = 1.52, 95% CI 1.01–2.29 to OR = 1.61, 95% CI 1.03–2.51; p < 0.04), independent of conventional risk factors and C-reactive protein concentrations or disease activity. Except for the OPG concentrations-plaque association (p = 0.09), these relationships remained significant subsequent to IFX administration (p < 0.05). Reductions in OPG levels related to those in vascular cell adhesion molecule (VCAM)-1 concentrations (partial R = 0.35, p = 0.04) and had borderline significance (p = 0.09) with those in ICAM-1 (partial R = 0.29) concentrations.Conclusion.: OPG concentrations are independently associated with endothelial activation and carotid atherosclerosis in RA. Reductions in OPG concentrations upon IFX administration are associated with decreased endothelial activation. OPG may be involved in increased cardiovascular disease risk and may improve its stratification in patients with RA.

Objective.: We determined whether osteoprotegerin (OPG) concentrations are associated with established cardiovascular disease (CVD) among patients with rheumatoid arthritis (RA).Methods.: OPG concentrations were measured by ELISA in 151 patients with RA (54 with CVD) and 62 age-matched control subjects without CVD. Established CVD was composed of documented ischemic heart disease, cerebrovascular disease, and peripheral artery disease.Results.: In patients with RA, age, body mass index (BMI), rheumatoid factor (RF) positivity, anticyclic citrullinated peptide (anti-CCP) antibody positivity, and joint erosion status were associated with OPG concentrations [partial R (p) = 0.175 (0.03), −0.277 (0.0009), 0.323 (< 0.0001), 0.217 (0.008), and 0.159 (0.05), respectively]. Median (interquartile range) OPG concentrations increased from 6.38 (3.46–9.31) to 7.07 (5.04–10.65) and 8.64 (6.00–11.52) ng/ml in controls and patients with RA who had CVD and those who did not, respectively (p = 0.0002). Upon adjustment for age, sex, traditional risk factors, and BMI in mixed regression models, OPG concentrations remained lower in controls compared to patients with RA without CVD (p = 0.05) and in the latter compared to those with CVD (p = 0.03); the association of OPG concentrations with CVD among patients with RA also persisted after additional adjustment for RF and anti-CCP antibody positivity, and erosion status (p = 0.04).Conclusion.: OPG concentrations are associated with disease severity and CVD prevalence in patients with RA. Whether consideration of OPG concentrations can improve CVD risk stratification in RA merits future longitudinal investigation.