Abstract P193: Prospective Association of Allostatic Load with Incident CVD in American Indians: The Strong Heart Study
Background: Chronic stress increases the risk of CVD. Allostatic load (AL) is a measure of multisystem physiological dysregulation resulting from long-term response to stress. American Indians (AIs) suffer higher rates of chronic stress and CVD, but no study has examined the association of AL with CVD in this high risk population.
Objective: To examine whether baseline AL predicts incident CVD in AIs in the Strong Heart Study.
Methods: Among 1400 apparently healthy AIs (free of CVD and diabetes at baseline) followed for an average of 7.8 years, we calculated AL score using 10 markers at baseline, including leukocyte telomere length, fasting glucose, total cholesterol, triglycerides, low- and high- density lipoprotein, estimated glomerular filtration rate, body mass index, and systolic and diastolic blood pressure. Each of the 10 markers was categorized as high or low risk according to criteria listed in Table 1. A composite AL score was calculated by summing the number of high-risk markers. CVD events were defined as fatal and nonfatal MI, congestive heart failure, and stroke. The association of baseline AL with incident CVD was examined by Cox proportional hazard model, adjusting for age, sex, study site, socioeconomic status, smoking and drinking at baseline.
Results: The mean age at baseline was 55±8 years. Participants with AL scores of 0, 1, 2, 3 and 4+ comprised of 20%, 30%, 28%, 13%, and 9%, respectively, of the study population. A total of 224 participants developed CVD during the follow-up period. Compared to participants with an AL score of 0, those with a score of 1, (HR=1.62 [1.00 - 2.62]), 2 (HR=2.28 [1.42 - 3.66]), 3 (HR=2.25 [1.33 - 3.80]), or 4+ (HR=3.06 [1.77 - 5.30]) had significantly higher risk for developing CVD. Moreover, there was a dose-response relationship between AL and CVD (trend P <0.001).
Conclusion: A higher AL score at baseline significantly predicts incident CVD among AIs, independent of sociodemographic and behavioral risk factors. The mechanisms underlying this association warrant further investigation.
Author Disclosures: H. Peng: None. F. Yeh: None. S. Cole: None. L. Best: None. M. Roman: None. E. Lee: None. B. Howard: None. J. Zhao: None.
- © 2016 by American Heart Association, Inc.