Background/Purpose: Patients with (RA) experience impaired inflammation induced arterial and endothelial function. Apelin can improve arterial function by enhancing the expression of endothelial nitric oxide synthase but this effect is dependent on endothelial integrity. We examined the potential effects of apelin on arterial function in RA.

Methods: Associations of apelin concentrations with SphygmoCor determined arterial stiffness (pulse wave velocity), wave reflection (augmentation index, reflected wave pressure and reflection magnitude) and pressure pulsatility (central systolic blood pressure (CSBP), central pulse pressure (CPP), peripheral pulse pressure (PPP), pulse pressure amplification (PPA) and forward wave pressure (FWP)) were identified in comprehensively adjusted multivariate regression models among 170 RA patients (112 white; 32 Asian; 22 black and 4 of mixed ancestry) without cardiovascular disease. Left ventricular stroke volume and ejection fraction were determined by echocardiography.

Results: Apelin concentrations were not independently associated with arterial function measures (p>/=0.15) in all patients. Joint deformity counts impacted the apelin-CSBP, apelin-CPP, apelin-PPamp and apelin-FWP relations (interaction p = 0.004, 0.01, 0.01 and < 0.01, respectively); the Disease Activity Score in 28 joints (DAS28) and erythrocyte sedimentation rate (ESR) influenced the apelin-CSBP association (interaction p = 0.04 and 0.05, respectively). In stratified analysis, apelin was associated with CSBP (partial r=-0.33, p=0.01), CPP (partial r=-0.26, p=0.04), PPamp (partial r=0.27, p=0.03) and FWP (patial r=-0.33, p=0.01) in patients without but not with joint deformities; apelin was related to CSBP (partial r=-0.24, p=0.05) in those with a DAS28 joint<2.8 (median value) (partial r=-0.24, p=0.05) but not >/=2.8, and to CSBP (partial r=-0.30, p=0.01), CPP (partial r=-0.25, p=0.03), PPamp (partial r=0.26, p=0.02) and FWP (patial r=-0.23, p=0.04) in those with an erythrocyte sedimentation rate<18 mm/hr (median value) but not >/= 18mm/hr. Apelin concentrations were not related to left ventricular stroke volume and ejection fraction, and upon additional adjustment for systolic function, the relationships of apelin concentrations with pressure pulsatility were unaltered.

Conclusion: Apelin is associated with reduced pressure pulsatility in RA patients without but not with a high inflammatory burden. Apelin can additionally improve systolic function through enhancing myofilament sensitivity to intracellular calcium whereas pressure pulsatility is mediated by not only arterial properties but also the episodic nature of cardiac contractility. The apelin-pressure pulsatility relations were independent of systolic function in this study. A loss of apelin protective effects on arterial function may contribute to the link between heightened cardiovascular risk and RA severity.

« Back to 2017 ACR/ARHP Annual Meeting

ACR Meeting Abstracts - https://acrabstracts.org/abstract/disease-severity-impacts-the-relationships-of-apelin-concentrations-with-arterial-function-in-patients-with-rheumatoid-arthritis/