Ent of hypertension, only about 50 of individuals have adequate blood SC66 supplier pressure (BP) lowering with any given drug therapy and less than 40 of hypertensive patients have controlled BP [2,3]. Additionally, there are well defined differences in drug response by race but mechanisms underlying these differences in response are poorly understood.b-blockers such as atenolol are important first line antihypertensive treatment, but not all patients respond and these drugs are associated with adverse metabolic effects, specifically adverse changes in glucose, triglycerides and uric acid, all of which can have negative cardiovascular consequences long-term [4,5]. Unfortunately, there are no well-defined biomarkers to identify patients that will have a beneficial therapeutic response or experience the adverse metabolic consequences of these drugs. Metabolomics is a global biochemical approach that provides powerful tools for defining perturbations in metabolic ��-Sitosterol ��-D-glucoside custom synthesis pathways and networks in human disease [6?0]. The metabolome defines a metabolic state as regulated by net interactions between gene and environmental influences and provides information that can possibly bridge the gap between genotype and phenotype. Targeted and non-targeted metabolomic approaches have beenEthnic Differences in Exposure to Atenololused to define pathways implicated in variation of response to drugs such as escitalopram [11] and simvastatin [12,13] leading to the emergence of a new field: pharmacometabolomics [9,14,15]. Indeed, pharmacometabolomics can be used to define a unique signature that represents changes in the metabolome induced by drug treatment. This signature can provide insight into the mechanism of variation in drug response caused by factors including race and genetics. In the present study, a mass spectrometry based global metabolomics approach was used to analyze effects of the bblocker atenolol in patients participating in the Pharmacogenomic Evaluation of Antihypertensive Responses (PEAR) study [16]. PEAR is a randomized clinical trial designed to identify genetic determinants of blood pressure and adverse metabolic responses to a thiazide diuretic and b-blocker. Responses to the b1-selective blocker atenolol or the diuretic 1081537 hydrochlorothiazide as monotherapy and then in combination were determined in 768 patients with mild to moderate hypertension. Metabolomic analyses were conducted in a subset of 272 patients receiving atenolol monotherapy. The objective of this study was to characterize the metabolomic signature of drug treatment as a first step to determine whether metabolomics might provide novel mechanistic insight into racial differences in response to b-blockers. Because the analysis showed a strong fatty acid signature that also differed by race, we tested the hypothesis that genetic variation in genes encoding lipases might be associated with observed atenololinduced changes in different racial groups.triplicate with each activation and to store the average systolic and diastolic BPs and the time of each set of measurements.Plasma samplesSubjects included in the metabolomics analyses (n = 272) were randomly selected from each quartile of blood pressure response, defined as the difference in BP after atenolol treatment 
from the BP at baseline. Subjects were balanced by race and to the extent possible by sex. Pre- and post-treatment fasting plasma samples were collected at baseline and after 9 weeks of atenolol treatment.GC-TOF Mass SpectrometryT.Ent of hypertension, only about 50 of individuals have adequate blood pressure (BP) lowering with any given drug therapy and less than 40 of hypertensive patients have controlled BP [2,3]. Additionally, there are well defined differences in drug response by race but mechanisms underlying these differences in response are poorly understood.b-blockers such as atenolol are important first line antihypertensive treatment, but not all patients respond and these drugs are associated with adverse metabolic effects, specifically adverse changes in glucose, triglycerides and uric acid, all of which can have negative cardiovascular consequences long-term [4,5]. Unfortunately, there are no well-defined biomarkers to identify patients that will have a beneficial therapeutic response or experience the adverse metabolic consequences of these drugs. Metabolomics is a global biochemical approach that provides powerful tools for defining perturbations in metabolic pathways and networks in human disease [6?0]. The metabolome defines a metabolic state as regulated by net interactions between gene and environmental influences and provides information that can possibly bridge the gap between genotype and phenotype. Targeted and non-targeted metabolomic approaches have beenEthnic Differences in Exposure to Atenololused to define pathways implicated in variation of response to drugs such as escitalopram [11] and simvastatin [12,13] leading to the emergence of a new field: pharmacometabolomics [9,14,15]. Indeed, pharmacometabolomics can be used to define a unique signature that represents changes in the metabolome induced by drug treatment. This signature can provide insight into the mechanism of variation in drug response caused by factors including race and genetics. In the present study, a mass spectrometry based global metabolomics approach was used to analyze effects of the bblocker atenolol in patients participating in the Pharmacogenomic Evaluation of Antihypertensive Responses (PEAR) study [16]. PEAR is a randomized clinical trial designed to identify genetic determinants of blood pressure and adverse metabolic responses to a thiazide diuretic and b-blocker. Responses to the b1-selective blocker atenolol or the diuretic 1081537 hydrochlorothiazide as monotherapy and then in combination were determined in 768 patients with mild to moderate hypertension. Metabolomic analyses were conducted in a subset of 272 patients receiving atenolol monotherapy. The objective of this study was to characterize the metabolomic signature of drug treatment as a first step to determine whether metabolomics might provide novel mechanistic insight into racial differences in response to b-blockers. Because the analysis showed a strong fatty acid signature that also differed by race, we tested the hypothesis that genetic variation in genes encoding lipases might be associated with observed atenololinduced changes in different racial groups.triplicate with 
each activation and to store the average systolic and diastolic BPs and the time of each set of measurements.Plasma samplesSubjects included in the metabolomics analyses (n = 272) were randomly selected from each quartile of blood pressure response, defined as the difference in BP after atenolol treatment from the BP at baseline. Subjects were balanced by race and to the extent possible by sex. Pre- and post-treatment fasting plasma samples were collected at baseline and after 9 weeks of atenolol treatment.GC-TOF Mass SpectrometryT.