Endothelial Activation Microparticles and Inflammation Status Improve with Exercise Training in African Americans

Dianne M Babbitt,Kathleen M Sturgeon,Keith M Diaz,Sheara T Williamson,Deborah L Feairheller,Deborah L Crabbe,Heather Grimm,Hojun Lee,Mohammed A Kashem,Amanda M Perkins,Chenyi Ling,Praveen Veerabhadrappa,Michael D Brown,Jan Kretzschmar,Sunny R Thakkar

doi:10.1155/2013/538017

Abstract

African Americans have the highest prevalence of hypertension in the world which may emanate from their predisposition to heightened endothelial inflammation. The purpose of this study was to determine the effects of a 6-month aerobic exercise training (AEXT) intervention on the inflammatory biomarkers interleukin-10 (IL-10), interleukin-6 (IL-6), and endothelial microparticle (EMP) CD62E+ and endothelial function assessed by flow-mediated dilation (FMD) in African Americans. A secondary purpose was to evaluate whether changes in IL-10, IL-6, or CD62E+ EMPs predicted the change in FMD following the 6-month AEXT intervention. A pre-post design was employed with baseline evaluation including office blood pressure, FMD, fasting blood sampling, and graded exercise testing. Participants engaged in 6 months of AEXT. Following the AEXT intervention, all baseline tests were repeated. FMD significantly increased, CD62E+ EMPs and IL-6 significantly decreased, and IL-10 increased but not significantly following AEXT. Changes in inflammatory biomarkers did not significantly predict the change in FMD. The change in VO2 max significantly predicted the change in IL-10. Based on these results, AEXT may be a viable, nonpharmacological method to improve inflammation status and endothelial function and thereby contribute to risk reduction for cardiovascular disease in African Americans.

Highlights

The most recent report (May 2012) from the World Health Organization, as well as the preponderance of published articles on hypertension and race, supports the conclusion that African Americans have the highest prevalence of hypertension in the world
The primary findings of the present study demonstrated that 6 months of aerobic exercise training (AEXT) elicited significant positive improvements in the inflammatory biomarkers IL-6 and CD62E+ endothelial microparticle (EMP), as well as the endothelial function marker flow-mediated dilation (FMD) in a cohort of middle-to-older-aged African Americans
Other studies that measured inflammatory biomarkers and endothelial function prior to and subsequent to AEXT have demonstrated similar results, but to our knowledge this is the first study that measured all of these complementary biomarkers prior to and subsequent to AEXT in an African American population

Summary

Introduction

The most recent report (May 2012) from the World Health Organization, as well as the preponderance of published articles on hypertension and race, supports the conclusion that African Americans have the highest prevalence of hypertension in the world. Research has demonstrated that African Americans have a greater prevalence of endothelial dysfunction when compared to their Caucasian counterparts, and researchers report that they suspect that this predisposes them to hypertension [1, 2]. Bautista reviewed multiple studies and reported a positive association between hypertension and some proinflammatory markers including C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor alpha (TNF-α) [4]. Experimental evidence has established that several proinflammatory cytokines, including IL-6, contribute to endothelial dysfunction which may lead to increased peripheral vascular resistance and hypertension [5]. Elevated circulating levels of IL-10 are associated with improved endothelial function in individuals with ongoing systemic inflammation [7] and in coronary artery disease (CAD) patients [3]

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