Abstract 048: Circulating Branched-Chain Amino Acids and Incident Cardiovascular Disease in a Prospective Cohort of US Women
Introduction: Recent metabolomics studies have identified circulating levels of branched-chain amino acids (BCAAs; isoleucine, leucine, valine) as strong predictors of type 2 diabetes (T2D). Whether BCAAs are implicated in cardiovascular disease (CVD) risk has not been established.
Hypothesis: We hypothesized that higher baseline levels of plasma BCAAs are associated with an elevated risk of incident CVD events, and evaluated whether this relationship was dependent on an intermediate diagnosis of T2D.
Methods: Participants enrolled in the Women’s Health Study prospective cohort were eligible if they did not report CVD or cancer prior to baseline blood collection (N=27,172, mean baseline age=54.7 years). Plasma BCAA metabolites were measured via proton NMR spectroscopy, ln-transformed, and standardized for analysis. We used multivariable Cox proportional regression models to estimate hazard ratios (HR) and 95% confidence intervals (CI) per standard deviation (SD) of total and individual BCAAs with incident CVD (myocardial infarction [MI], stroke, coronary revascularization).
Results: 1,917 confirmed CVD events occurred over follow-up (mean 18.6 years). In models adjusted for age, body mass index, smoking status, diet quality, physical activity, and other established CVD risk factors, total BCAAs were positively associated with CVD (per SD, HR=1.13, CI=1.08 to 1.19), comparable in magnitude to the association of LDL cholesterol with CVD (per SD, HR=1.15, CI=1.09 to 1.21). In particular, BCAAs were associated with coronary events (MI: HR=1.21, CI=1.10 to 1.33; revascularization: HR=1.15, CI=1.07 to 1.23), but not with stroke (HR=1.07, CI=0.98 to 1.15). The BCAA-CVD relationship was notably greater (p-interaction=0.008) among participants who developed T2D prior to a CVD event (HR=1.25, CI=1.13 to 1.39), vs. women without T2D (HR=1.07, CI=1.01 to 1.13). Isoleucine, leucine, and valine were each associated with CVD (p<0.05). Further adjusting for biomarkers of potential intermediates, HbA1c, lipids, and a lipoprotein-based insulin resistance score entirely eliminated the associations of BCAAs with CVD.
Conclusions: Circulating plasma BCAAs were positively associated with long-term incident CVD in a cohort of US women, in particular among women who developed T2D prior to a CVD event. Impaired BCAA metabolism may represent a shared pathway of insulin resistance that links the risks of T2D and CVD.
Author Disclosures: D.K. Tobias: None. P.R. Lawler: None. P.H. Harada: None. O.V. Demler: None. P.M. Ridker: None. J.E. Manson: None. S. Cheng: None. S. Mora: None.
- © 2018 by American Heart Association, Inc.