Abstract 19721: Circulating miR-146a Shows Positive Correlation with Arterial Stiffness and Negative Correlation with Aerobic Exercise Capacity Among Healthy Adults
Background: miR-146a is a micro-RNA expressed in many cell types, with increased expression in response to inflammation via TLR activation, leading to negative feedback regulation of inflammatory pathways. miR-146a has been associated with atherosclerosis, abdominal aortic aneurysm and ischemic stroke. Circulating miR-146a (c-miR-146a) levels are higher in hyperglycemia, hyperlipidemia and acute coronary syndrome. c-miR-146a levels may change variably in response to exercise in healthy individuals. We hypothesized that c-miR-146a will be associated with sub-clinical vascular disease and explored its relationship with measures of arterial stiffness and cardiopulmonary fitness.
Methods: In 39 healthy (no medications, screened for absence of hypertension, hyperlipidemia, diabetes and obesity) non-smoking volunteers, 56% male, aged 46.53 ± 11years, enrolled in Emory’s preventive health initiative study, we performed qPCR (TaqMan) for serum miR-146a levels and normalized to miR-346 (shown to have stable levels in serum among healthy individuals and CAD patients). Arterial stiffness was assessed using carotid-femoral pulse wave velocity (PWV) and cardiopulmonary fitness using peak oxygen uptake at maximal exercise expressed as percent of predicted value (%pPVO2). Relationships between these parameters and c-miR-146a levels were explored using Spearman’s correlation in bivariate analysis and after multivariate correction for age, gender and BMI.
Results: The mean PWV was 6.78 ± 1.03m/s, %pPVO2 110.7 ± 31.7 and relative c-miR-146a expression 0.39 ± 0.29. There was a strong correlation between increasing PWV (r=0.451, p=0.006) and decreasing %pPVO2 (r=-0.277, p=0.044) with higher c-miR-146a expression. After multivariate adjustment for age, gender and BMI, relative c-miR-146a expression correlated independently with PWV (β=0.43; p=0.013) and %pPVO2 (β=-0.336, p=0.024).
Conclusion: In healthy subjects, higher c-miR-146a levels are associated with increased arterial stiffness and reduced cardiopulmonary fitness. Circulating miR-146a levels may be used as a biomarker for subclinical vascular disease and whether at this stage it is mechanistically involved in disease or is a consequence of inflammation needs further study.
Author Disclosures: A. Rezvan: None. K. Rooney: None. I. Al Mheid: None. N. Ghasemzadeh: None. H. Jo: None. A.A. Quyyumi: None. C.D. Searles: None.
- © 2014 by American Heart Association, Inc.