ASSOCIATIONS BETWEEN PLASMA METABOLOMICS AND BLOOD PRESSURE ACROSS ETHNICITIES: THE HELIUS STUDY

OBJECTIVE: Blood pressure (BP) is regulated by plasma metabolites from different neurohumoral and cardiometabolic systems. Since there are well-established differences in hypertension pathogenesis and treatment response between ethnicities, we hypothesized that plasma metabolites may be differently associated with BP across ethnic groups. DESIGN AND METHOD: From the HELIUS study, 369 subjects (mean age 52 ± 11 years, 51%F) of African and non-African descent were included. Office systolic and diastolic BP levels were recorded. Plasma metabolites were measured with untargeted LC-MS from fasting plasma samples. Associations between metabolite profiles and BP were assessed with machine learning prediction models. Associations between the resulting best predictors and BP were assessed with linear regression models while adjusting for age, sex, renal function and diabetes, and interactions with ethnicity were tested. RESULTS: Plasma metabolite profiles explained 14.1% of systolic BP variance and 10.6% of diastolic BP variance. Top predictors for both systolic and diastolic BP included N-formylmethionine, several acylcarnitines and polyunsaturated fatty acids such as hexadecadienoate. These metabolites were significantly associated with higher systolic BP with estimates ranging from 3.0-4.5 mmHg per 1 SD increase in the adjusted models. Associations with hexadecadienoate, dihomolinoleate and catecholamine metabolites, including vanillactate had significant interactions with ethnicity and were only significant in subjects of non-African descent. The top predictor N-formylmethionine was the most consistent predictor across ethnicities and sex. This metabolite was associated with higher levels of nitric oxide (NO)-related metabolites, including dimethylarginine (r = 0.42, p < 0.001) and citrulline (r = 0.24, p < 0.0001). CONCLUSIONS: Plasma metabolome composition explained a large proportion of BP variance, but best predicting metabolites were differently associated with BP across ethnicities. N-formylmethionine was the most consistent predictor for BP across ethnicities and sex. This metabolite was associated with metabolites in the NO-pathway. We hypothesize that formylmethionine affects BP through the inhibition of endothelial NO formation.