Clonal haematopoiesis, ageing and kidney disease.

Clonal haematopoiesis of indeterminate potential (CHIP) is a preclinical condition wherein a sizeable proportion of an individual's circulating blood cells are derived from a single mutated haematopoietic stem cell. CHIP occurs frequently with ageing - more than 10% of individuals over 65 years of age are affected - and is associated with an increased risk of disease across several organ systems and premature death. Emerging evidence suggests that CHIP has a role in kidney health, including associations with predisposition to acute kidney injury, impaired recovery from acute kidney injury and kidney function decline, both in the general population and among those with chronic kidney disease. Beyond its direct effect on the kidney, CHIP elevates the susceptibility of individuals to various conditions that can detrimentally affect the kidneys, including cardiovascular disease, obesity and insulin resistance, liver disease, gout, osteoporosis and certain autoimmune diseases. Aberrant pro-inflammatory signalling, telomere attrition and epigenetic ageing are potential causal pathophysiological pathways and mediators that underlie CHIP-related disease risk. Experimental animal models have shown that inhibition of inflammatory cytokine signalling can ameliorate many of the pathological effects of CHIP, and assessment of the efficacy and safety of this class of medications for human CHIP-associated pathology is ongoing.

Analytical and Biological Variability of a Commercial Modified Aptamer Assay in Plasma Samples of Patients with Chronic Kidney Disease.

BACKGROUND: We carried out a study of the aptamer proteomic assay, SomaScan V4, to evaluate the analytical and biological variability of the assay in plasma samples of patients with moderate to severe chronic kidney disease (CKD). METHODS: Plasma samples were selected from 2 sources: (a) 24 participants from the Chronic Renal Insufficiency Cohort (CRIC) and (b) 49 patients from the Brigham and Women's Hospital-Kidney/Renal Clinic. We calculated intra-assay variability from both sources and examined short-term biological variability in samples from the Brigham clinic. We also measured correlations of aptamer measurements with traditional biomarker assays. RESULTS: A total of 4656 unique proteins (4849 total aptamer measures) were analyzed in all samples. Median (interquartile range [IQR] intra-assay CV) was 3.7% (2.8-5.3) in CRIC and 5.0% (3.8-7.0) in Brigham samples. Median (IQR) biological CV among Brigham samples drawn from one individual on 2 occasions separated by median (IQR) 7 (4-14) days was 8.7% (6.2-14). CVs were independent of CKD stage, diabetes, or albuminuria but were higher in patients with systemic lupus erythematosus. Rho correlations between aptamer and traditional assays for biomarkers of interest were cystatin C = 0.942, kidney injury model-1 = 0.905, fibroblast growth factor-23 = 0.541, tumor necrosis factor receptors 1 = 0.781 and 2 = 0.843, P < 10-100 for all. CONCLUSIONS: Intra-assay and within-subject variability for SomaScan in the CKD setting was low and similar to assay variability reported from individuals without CKD. Intra-assay precision was excellent whether samples were collected in an optimal research protocol, as were CRIC samples, or in the clinical setting, as were the Brigham samples.

Multi-ancestry transcriptome-wide association analyses yield insights into tobacco use biology and drug repurposing.

Most transcriptome-wide association studies (TWASs) so far focus on European ancestry and lack diversity. To overcome this limitation, we aggregated genome-wide association study (GWAS) summary statistics, whole-genome sequences and expression quantitative trait locus (eQTL) data from diverse ancestries. We developed a new approach, TESLA (multi-ancestry integrative study using an optimal linear combination of association statistics), to integrate an eQTL dataset with a multi-ancestry GWAS. By exploiting shared phenotypic effects between ancestries and accommodating potential effect heterogeneities, TESLA improves power over other TWAS methods. When applied to tobacco use phenotypes, TESLA identified 273 new genes, up to 55% more compared with alternative TWAS methods. These hits and subsequent fine mapping using TESLA point to target genes with biological relevance. In silico drug-repurposing analyses highlight several drugs with known efficacy, including dextromethorphan and galantamine, and new drugs such as muscle relaxants that may be repurposed for treating nicotine addiction.

Examination of serum metabolome altered by cigarette smoking identifies novel metabolites mediating smoking-BMI association.

OBJECTIVE: The authors hypothesize that an untargeted metabolomics study will identify novel mechanisms underlying smoking-associated weight loss. METHODS: This study performed cross-sectional analyses among 1,252 participants in the Bogalusa Heart Study and assessed 1,202 plasma metabolites for mediation effects on smoking-BMI associations. Significant metabolites were tested for associations with smoking genetic risk scores among a subset of participants (n = 654) with available genomic data, followed by direction dependence analysis to investigate causal relationships between the metabolites and smoking and BMI. All analyses controlled for age, sex, race, education, alcohol drinking, and physical activity. RESULTS: Compared with never smokers, current and former smokers had a 3.31-kg/m2 and 1.77-kg/m2 lower BMI after adjusting for all covariables, respectively. A total of 22 xenobiotics and 94 endogenous metabolites were significantly associated with current smoking. Eight xenobiotics were also associated with former smoking. Forty metabolites mediated the smoking-BMI associations, and five showed causal relationships with both smoking and BMI. These metabolites, including 1-oleoyl-GPE (18:1), 1-linoleoyl-GPE (18:2), 1-stearoyl-2-arachidonoyl-GPE (18:0/20:4), α-ketobutyrate, and 1-palmitoyl-GPE (16:0), mediated 26.0% of the association between current smoking and BMI. CONCLUSIONS: This study cataloged plasma metabolites altered by cigarette smoking and identified five metabolites that partially mediated the association between current smoking and BMI.

Association Between Baseline Buccal Telomere Length and Progression of Kidney Function: The Health and Retirement Study.

We aimed to evaluate associations of baseline telomere length with overall and annual change in estimated glomerular filtration rate (eGFR) and trajectory of kidney function during an 8-year follow-up. A total of 3 964 participants of the Health and Retirement Study were included. We identified 3 trajectory groups of kidney function: consistently normal (n = 1 163 or 29.3%), normal to impaired (n = 2 306 or 58.2%), and consistently impaired groups (n = 495 or 12.5%). After controlling for age, sex, race, education, smoking, drinking, diabetes, heart disease, blood pressure, body mass index, total cholesterol, and hemoglobin A1c, participants with longer telomere length were 20% less likely (odds ratio = 0.80, 95% confidence interval: 0.69-0.93, p = .003) to have a normal to impaired kidney function trajectory than a consistently normal function trajectory. Telomere length was not associated with changing rate of eGFR over 8 years (p = .45). Participants with longer telomere length were more likely to have consistently normal kidney function.

Secular Trends in Cardiovascular Health in US Adults (from NHANES 2007 to 2018).

Deceleration in the decline of cardiovascular disease mortality has been observed recently in the US. We aimed to examine the recent secular trends of cardiovascular health metrics in the US general population. A total of 32,832 adults aged ≥20 years from the National Health and Nutrition Examination Surveys 2007 to 2018 were included in this analysis. Cardiovascular health included 7 health metrics: smoking status, body mass index, physical activity, healthy diet score, total cholesterol, blood pressure, and fasting plasma glucose. Age-standardized mean of overall cardiovascular health score did not significantly change during 2007 to 2010, 2011 to 2014, and 2015 to 2018 in the US adult population (7.88, 8.03, and 7.91, respectively, P-trend = 0.85). The age-standardized proportions of ideal smoking status (P-trend = 0.003), ideal physical activity (P-trend = 0.03), and untreated total cholesterol <200 mg/dL (P-trend <0.001) were significantly increased but the proportions of body mass index <25.0 kg/m2 (P-trend <0.001), systolic/diastolic blood pressure <120/80 mmHg (P-trend = 0.02), and fasting plasma glucose <100 mg/dL (P-trend <0.001) were significantly decreased during the same period of time in the US adults. In conclusion, from 2007 to 2018, overall cardiovascular health did not change in the US general adult population. Of note, body mass index, blood pressure, and fasting plasma glucose significantly worsened during the same period.

Serum metabolites associate with physical performance among middle-aged adults: Evidence from the Bogalusa Heart Study.

Age-related declines in physical performance predict cognitive impairment, disability, chronic disease exacerbation, and mortality. We conducted a metabolome-wide association study of physical performance among Bogalusa Heart Study participants. Bonferroni corrected multivariate-adjusted linear regression was employed to examine cross-sectional associations between single metabolites and baseline gait speed (N=1,227) and grip strength (N=1,164). In a sub-sample of participants with repeated assessments of gait speed (N=282) and grip strength (N=201), significant metabolites from the cross-sectional analyses were tested for association with change in physical performance over 2.9 years of follow-up. Thirty-five and seven metabolites associated with baseline gait speed and grip strength respectively, including six metabolites that associated with both phenotypes. Three metabolites associated with preservation or improvement in gait speed over follow-up, including: sphingomyelin (40:2) (P=2.6×10-4) and behenoyl sphingomyelin (d18:1/22:0) and ergothioneine (both P<0.05). Seven metabolites associated with declines in gait speed, including: 1-carboxyethylphenylalanine (P=8.8×10-5), and N-acetylaspartate, N-formylmethionine, S-adenosylhomocysteine, N-acetylneuraminate, N2,N2-dimethylguanosine, and gamma-glutamylphenylalanine (all P<0.05). Two metabolite modules reflecting sphingolipid and bile acid metabolism associated with physical performance (minimum P=7.6×10-4). These results add to the accumulating evidence suggesting an important role of the human metabolome in physical performance and specifically implicate lipid, nucleotide, and amino acid metabolism in early physical performance decline.

Pooled cohort equations heart failure risk score predicts cardiovascular disease and all-cause mortality in a nationally representative sample of US adults.

BACKGROUND: Heart failure (HF) represents an accumulated burden of systemic vascular damage and is the fastest growing form of cardiovascular disease (CVD). Due to increasing HF-attributable mortality rates, we sought to assess the association of the new 2019 Pooled Cohort equations to Prevent Heart Failure (PCP-HF) risk score with CVD and all-cause mortality. METHODS: We linked data for 6333 black and white men and women aged 40-79 years, whom underwent electrocardiographic examination from the Third National Health and Nutrition Exam Survey, to National Death Index record matches. Sex- and race-specific PCP-HF risk scores were calculated using data on age, smoking, body mass index, systolic blood pressure, total cholesterol, HDL-cholesterol, fasting blood glucose, QRS complex duration, and antihypertensive and/or glucose-lowering medications. Cox regression estimated hazard ratios for the association of the PCP-HF risk score with CVD and all-cause mortality. RESULTS: Individuals were on average 54.9 years old (51.7% women, 25.4% black) and the median 10-year HF risk was 1.6% (Q1 = 0.5, Q3 = 4.8). There were 3178 deaths, 1116 from CVD, over a median follow-up time of 22.3 years. Black women had a higher 10-year HF risk compared to white women (2.1% vs. 1.1%; p < 0.01), while no significant difference was observed in predicted HF risk between black men and white men (2.3% vs. 2.1%, p = 0.16). A two-fold higher PCP-HF risk score was associated with a significant 58% (HR = 1.58; 95% CI, 1.48-1.70; p < 0.0001) and 38% (HR = 1.38; 95% CI, 1.32-1.46; p < 0.0001) greater risk of CVD and all-cause mortality, respectively. CONCLUSION: The PCP-HF risk score predicts CVD and all-cause mortality, in addition to the 10-year risk of incident HF among white and black men and women. These results underline the expanded utility of the PCP-HF risk score and suggest that its implementation in the clinical and population health settings may improve primary CVD prevention in the United States.

Coronary Artery Calcium and the Age-Specific Competing Risk of Cardiovascular Versus Cancer Mortality: The Coronary Artery Calcium Consortium.

BACKGROUND: Coronary artery calcium (CAC) is a guideline recommended cardiovascular disease (CVD) risk stratification tool that increases with age and is associated with non-cardiovascular disease outcomes including cancer. We sought to define the age-specific change in the association between CAC and cause-specific mortality. METHODS: The Coronary Artery Calcium Consortium includes 59,502 asymptomatic patients age 40-75 without known CVD. Age-stratified mortality rates and parametric survival regression modeling was performed to estimate the age-specific CAC score at which CVD and cancer mortality risk were equal. RESULTS: The mean age was 54±8 years (67% men) and there were 2,423 deaths over a mean 12±3 years follow-up. Among individuals with CAC = 0, cancer was the leading cause of death, with low CVD mortality rates for both younger (40-54 years) 0.2/1,000 person-years and older participants (65-75 years) 1.3/1,000 person-years. When CAC ≥400, CVD was consistently the leading cause of death among younger (71% of deaths) and older participants (56% of deaths). The CAC score at which CVD overtook cancer as the leading cause of death increased exponentially with age and was approximately 115 at age 50 and 380 at age 65. CONCLUSIONS: Regardless of age, when CAC = 0 cancer was the leading cause of death and the cardiovascular disease mortality rate was low. Our age-specific estimate for the CAC score at which CVD overtakes cancer mortality allows for a more precise approach to synergistic prediction and prevention strategies for CVD and cancer.

Novel associations between blood metabolites and kidney function among Bogalusa Heart Study and Multi-Ethnic Study of Atherosclerosis participants.

INTRODUCTION: Chronic kidney disease (CKD) is a major public health challenge given its high global prevalence and associated risks of cardiovascular disease and progression to end stage renal disease. Although it is known that numerous metabolic changes occur in CKD patients, identifying novel metabolite associations with kidney function may enhance our understanding of the physiologic pathways relating to CKD. OBJECTIVES: The objective of this study was to elucidate novel metabolite associations with kidney function among participants of two community-based cohorts with carefully ascertained metabolomics, kidney function, and covariate data. METHODS: Untargeted ultrahigh-performance liquid chromatography-tandem mass spectrometry was used to detect and quantify blood metabolites. We used multivariate adjusted linear regression to examine associations between single metabolites and creatinine-based estimated glomerular filtration rate (eGFRcr) among 1243 Bogalusa Heart Study (BHS) participants (median eGFRcr: 94.4, 5th-95th percentile: 66.0-119.6 mL/min/1.73 m2). Replication, determined by statistical significance and consistent effect direction, was tested using gold standard measured glomerular filtration rate (mGFR) among 260 Multi-Ethnic Study of Atherosclerosis (MESA) participants (median mGFR: 72.0, 5th-95th percentile: 43.5-105.0 mL/min/1.73 m2). All analyses used Bonferroni-corrected alpha thresholds. RESULTS: Fifty-one novel metabolite associations with kidney function were identified, including 12 from previously unrelated sub-pathways: N6-carboxymethyllysine, gulonate, quinolinate, gamma-CEHC-glucuronide, retinol, methylmalonate, 3-hydroxy-3-methylglutarate, 3-aminoisobutyrate, N-methylpipecolate, hydroquinone sulfate, and glycine conjugates of C10H12O2 and C10H14O2(1). Significant metabolites were generally inversely associated with kidney function and smaller in mass-to-charge ratio than non-significant metabolites. CONCLUSION: The 51 novel metabolites identified may serve as early, clinically relevant, kidney function biomarkers.

Novel Metabolites Are Associated With Augmentation Index and Pulse Wave Velocity: Findings From the Bogalusa Heart Study.

BACKGROUND: Metabolomics study may help identify novel mechanisms underlying arterial stiffening. METHODS: We performed untargeted metabolomics profiling among 1,239 participants of the Bogalusa Heart Study. After quality control, 1,202 metabolites were evaluated for associations with augmentation index (AI) and pulse wave velocity (PWV), using multivariate linear regression adjusting for age, sex, race, education, smoking, drinking, body weight, body height, physical activity, and estimated glomerular filtration rate. Heart rate, blood pressure and antihypertensive medication usage, lipids, and fasting glucose were sequentially adjusted in the sensitivity analyses for significant metabolites. Weighted correlation network analysis was applied to build metabolite networks. RESULTS: Six novel metabolites were negatively associated with AI, of which, 3-methyl-2-oxobutyrate had the lowest P value and the largest effect size (ß = -6.67, P = 5.99 × 10-6). Heart rate contributed to a large proportion (25%-58%) of the association for each metabolite. Twenty-one novel metabolites were identified for PWV, of which, fructose (ß = 0.61, P = 6.18 × 10-10) was most significant, and histidine had the largest effect size (ß = -1.09, P = 2.51 × 10-7). Blood pressure played a major contribution (9%-54%) to the association for each metabolite. Furthermore, 16 metabolites were associated with arterial stiffness independent of traditional risk factors. Network analysis identified 2 modules associated with both AI and PWV (P < 8.00 × 10-4). One was composed of metabolites from the glycerolipids synthesis and recycling pathway, and the other was involved in valine, leucine, and isoleucine metabolism. One module related to sphingomyelin metabolism was associated with PWV only (P = 0.002). CONCLUSIONS: This study has identified novel and important metabolites and metabolic networks associated with arterial stiffness.

History of Asthma From Childhood and Arterial Stiffness in Asymptomatic Young Adults: The Bogalusa Heart Study.

Asthma is related to various cardiovascular risk. Whether a history of asthma from childhood contributes to arterial stiffness in adulthood, a noninvasive surrogate for cardiovascular events, is unknown. Prospective analyses were performed among 1746 Bogalusa Heart Study participants aged 20 to 51 years with data on self-report asthma collected since childhood. Aorta-femoral pulse wave velocity (af-PWV, m/s) was repeatedly assessed among adults ≥aged 18 years. Generalized linear mixed models and generalized linear models were fitted for the repeated measurements of af-PWV and its changes between the last and the first measurements, respectively. After a median follow-up of 11.1 years, participants with a history of asthma from childhood had a higher af-PWV (6.78 versus 6.13; P=0.048) and a greater increase in af-PWV (8.99 versus 2.95; P=0.043) than those without asthma, adjusted for age, sex, race, smoking status, heart rate, body mass index, systolic blood pressure, lipids, and glycemia. In addition, we found significant interactions of asthma with body mass index and systolic blood pressure on af-PWV and its changes (P for interaction <0.01). The associations of asthma with af-PWV and its changes appeared to be stronger among participants who were overweight and obese (body mass index ≥25 kg/m2) or with prehypertension and hypertension (systolic blood pressure ≥120 mm Hg) compared with those with a normal body mass index or systolic blood pressure. Our findings indicate that a history of asthma from childhood is associated with higher af-PWV and greater increases in af-PWV, and such associations are stronger among young adults who are overweight or with elevated blood pressure.

Differential sex effects of systolic blood pressure and low-density lipoprotein cholesterol on type 2 diabetes: Life course data from the Bogalusa Heart Study.

BACKGROUND: There may be sex-specific cardiometabolic mechanisms early in life that affect the development of type 2 diabetes mellitus (T2DM) through mid-adulthood. However, few studies have examined whether early life course interactions between cardiometabolic risk factors and sex are associated with incident T2DM. METHODS: This study followed 7725 children (3834 [49.6%] females, 3891 [50.4%] males) from the Bogalusa Heart Study through mid-adulthood to examine whether low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), body mass index (BMI), or systolic blood pressure (SBP) differentially affect the risk of T2DM for females versus males. Potential sex interactions were tested after adjusting for age, race, triglycerides, smoking, follow-up time, puberty stage, use of birth control, and enrollment year. RESULTS: Mean (± SD) age at baseline was 9.4 ± 3.5 years. There were 176 cases of T2DM (cumulative incidence = 2.3%) during a median follow-up of 9.1 years. In females versus males, LDL-C and SBP were differentially associated with T2DM (P ≤ 0.001 and P = 0.017, respectively). The relationships of BMI and HDL-C with T2DM were non-differential between females and males (P = 0.79 and P = 0.27, respectively). CONCLUSIONS: This study is the first to show evidence of sex-specific differential effects of LDL-C and SBP on the risk of T2DM from childhood to adulthood. Greater LDL-C places girls at disproportionally higher risk of T2DM as women, whereas greater SBP differentially exposes boys to a greater risk of T2DM as men. Additional studies within existing child cohorts are needed to confirm and investigate the mechanisms underlying these differential effects.

A History of Asthma From Childhood and Left Ventricular Mass in Asymptomatic Young Adults: The Bogalusa Heart Study.

OBJECTIVES: This study aimed to examine whether a history of asthma from childhood is associated with left ventricular (LV) mass in adulthood. BACKGROUND: Asthma has been related to various cardiovascular risk factors affecting LV hypertrophy. The authors saw a need for a prospective study to analyze the relationship between a history of asthma from childhood and markers of LV mass among asymptomatic young adults. METHODS: Prospective analyses were performed among 1,118 Bogalusa Heart Study participants (average age at follow-up 36.7 ± 5.1 years), with a baseline history of self-reported asthma collected since childhood (average age at baseline 26.8 ± 10.1 years). LV mass (g) was assessed using 2-dimensional guided M-mode echocardiography and was indexed for body height (m2.7) as LV mass index (LVMI; g/m2.7). A multivariate linear mixed model was fitted for the repeated measures. RESULTS: After an average of 10.4 ± 7.5 years of follow-up, participants with a history of asthma from childhood had a greater LV mass (167.6 vs. 156.9; p = 0.01) and LVMI (40.7 vs. 37.7; p < 0.01) with adjustment for age, sex, race, smoking status, antihypertensive medication, heart rate, and systolic blood pressure (SBP). The difference of LVMI between group with asthma and the group without asthma remained significant after additional adjustment for body mass index (39.0 vs. 37.1; p = 0.03) and high-sensitivity C-reactive protein (38.4 vs. 36.6; p = 0.04). In addition, the authors found significant interactions between SBP and asthma on LV mass and LVMI (p for interaction <0.01, respectively). The associations between asthma and LV measures appeared to be stronger among pre-hypertensive and hypertensive participants (SBP ≥130 mm Hg) compared with participants with normal SBP (<130 mm Hg) (regression coefficient: 39.5 vs. 2.3 for LV mass and 9.0 vs. 0.9 for LVMI). CONCLUSIONS: The findings of this study indicate that a history of asthma is associated with higher LVMI, and this association is stronger among participants with pre-hypertension and hypertension.

Diabetes mellitus and colorectal cancer prognosis: a meta-analysis.

BACKGROUND: Diabetes mellitus is associated with an increased incidence of colorectal cancer, but the impact of diabetes mellitus on colorectal cancer prognosis is not clear. OBJECTIVE: We conducted a meta-analysis of observational studies to examine the association between preexisting diabetes mellitus and colorectal cancer all-cause mortality, cancer-specific mortality, and recurrence. DATA SOURCES: Medline and Embase were searched through August 22, 2012. STUDY SELECTION: We included studies reporting all-cause mortality, cancer-specific mortality, disease-free survival, or recurrence in patients who have colorectal cancer according to diabetic status. INTERVENTION: Meta-analyses were performed by the use of random-effects models. MAIN OUTCOME MEASURES: The primary outcomes measured were all-cause mortality, cancer-specific mortality, and disease-free survival. RESULTS: Twenty-six articles met our inclusion criteria. Patients with colorectal cancer who had diabetes mellitus had a 17% increased risk of all-cause mortality (relative risk, 1.17; 95% CI, 1.09-1.25) and a 12% increased risk of cancer-specific mortality (relative risk, 1.12; 95% CI, 1.01-1.24) in comparison with those who did not have diabetes mellitus. Those with diabetes mellitus also had poorer disease-free survival (relative risk, 1.54; 95% CI, 1.08-2.18) compared with their nondiabetic counterparts. In subgroup analyses, diabetes mellitus was associated with all-cause mortality in both rectal (relative risk, 1.24; 95% CI, 1.07-1.29) and colon cancer patients (relative risk, 1.17; 95% CI, 1.07-1.29). Sensitivity analyses including only patients with nonmetastatic disease identified stronger associations between diabetes mellitus and both all-cause (relative risk, 1.32; 95% CI, 1.21-1.44) and cancer-specific (relative risk, 1.27; 95% CI, 1.06-1.52) mortality. LIMITATIONS: Some studies had short follow-up or did not report mean or median follow-up. The included studies were heterogeneous in study population, diabetes mellitus diagnostic criteria, and outcome ascertainment. CONCLUSION: Patients with colorectal cancer who have diabetes mellitus are at greater risk for all-cause and cancer-specific mortality and have worse disease-free survival than those who do not have diabetes mellitus. Studies are warranted to determine whether the proper treatment could attenuate the excess mortality among patients with colorectal cancer who have diabetes mellitus.

Analysis of sex hormone genes reveals gender differences in the genetic etiology of blood pressure salt sensitivity: the GenSalt study.

BACKGROUND: We examined the association between 799 single-nucleotide polymorphisms in 39 sex hormone genes and blood pressure (BP) responses to a dietary-sodium intervention. METHODS: A 7-day low-sodium feeding study (51.3 mmol sodium/day) followed by a 7-day high-sodium feeding study (307.8 mmol sodium/day) was conducted among 1,906 Han Chinese participants. Nine BP measurements were obtained at baseline and the end of each intervention period using a random-zero sphygmomanometer. RESULTS: Among men, absolute BP responses to sodium interventions decreased with the number of minor alleles of estrogen receptor 1 (ESR1) markers rs9340844, rs9397453, rs9371562, rs9397459, and rs9383951. For example, mean diastolic blood pressure (DBP) responses to low-sodium intervention (95% confidence interval) were -2.67 (-3.13, -2.22) mm Hg among those with the rs9397453 C/C genotype, -1.23 (-1.98, -0.48) mm Hg among those with the C/T genotype, and 0.08 (-2.31, 2.47) mm Hg among those with the T/T genotype (P = 1×10(-4); false discovery rate (FDR)-q = 0.04). Mean DBP responses to high sodium according to the rs9397453 genotypes were 1.46 (1.03, 1.89) mm Hg among those with C/C, 0.19 (-0.54, 0.91) mm Hg among those with C/T, and -1.10 (-2.82, 0.61) mm Hg among those with T/T (P = 2×10(-4); FDR-q = 0.04). Similar trends were noted for the association between these ESR1 variants and SBP responses to the dietary intervention. There were no significant associations between sex hormone gene variants and salt sensitivity in women, with genotype-gender interactions noted for the ESR1 markers that achieved significance in men. CONCLUSIONS: We identified strong, consistent associations between ESR1 gene variants and salt sensitivity in men. Our results support a gender-specific role for ESR1 in the etiology of this complex trait.

Association of inflammation and endothelial dysfunction with metabolic syndrome, prediabetes and diabetes in adults from Inner Mongolia, China.

BACKGROUND: We examined the association of biomarkers of inflammation and endothelial dysfunction with diabetes and metabolic syndrome (MetS) in persons from Inner Mongolia. METHODS: A cross-sectional study was conducted among 2,536 people aged 20 years and older from Inner Mongolia, China. Overnight fasting blood samples were obtained to measure plasma concentrations of high sensitivity C-reactive protein (hsCRP), soluble inter-cellular adhesion molecule-1 (sICAM-1), sE-selectin, angiotensin II, high density lipoprotein cholesterol, triglycerides, and blood glucose. Waist circumference and blood pressure were measured by trained staff. MetS was defined according to the modified ATP III definition for Asians. Elevated level of the biomarker was defined as values in the upper tertile of the distribution. Participants were categorized into one of four groups based on the presence or absence of metabolic and glycemic abnormalities: 1) free of prediabetes, diabetes and MetS (reference group), 2) prediabetes or diabetes only, 3) MetS without prediabetes or diabetes, and 4) MetS plus prediabetes or diabetes. The multivariable models are adjusted for age, gender, smoking, drinking, family history of hypertension, and body mass index. RESULTS: Among study participants, 18.5% had prediabetes, 3.6% had diabetes, and 27.4% of the entire study population had 3 or more components of the MetS. Elevated hsCRP was associated with an increased odds of prediabetes or diabetes only, MetS without prediabetes or diabetes, and MetS plus prediabetes or diabetes with multivariable adjusted odds ratios (95% confidence intervals) of 2.3 (1.7-3.1), 3.0 (2.4-3.8), and 5.8 (4.5-7.5), respectively. Elevated sICAM-1 was associated with increased odds (95% CI) of prediabetes or diabetes only (2.1, 1.6-2.9) and MetS plus prediabetes or diabetes (4.2, 3.2-5.3) but was not associated with MetS alone. Elevated sE-selectin was associated with a modestly increased risk of MetS (OR 1.7, 95% CI 1.4-2.2). Elevated levels of Angiotensin II were not associated with the MetS plus prediabetes or diabetes in this study. CONCLUSIONS: Diabetes and the MetS are common in the Inner Mongolia population. The biomarkers of inflammation and endothelial dysfunction are associated with increased risk for diabetes and MetS in this population. These results are consistent with results from other populations.

Interactions of genetic variants with physical activity are associated with blood pressure in Chinese: the GenSalt study.

BACKGROUND: Blood pressure (BP) homeostasis involves complex interactions among genetic and nongenetic factors, providing major challenges to dissection of the genetic components that influence BP and hypertension. In this study, we examine the effects of interaction of genetic variants with physical activity on BP in a relatively genetically homogenous cohort of rural Chinese villagers. METHODS: Generalized estimating equations analysis was used to test for associations of systolic blood pressure (SBP) and diastolic blood pressure (DBP) with variants in 24 genes in BP pathways (196 single-nucleotide polymorphisms (SNPs)) among 3,142 Chinese participants divided according to physical activity (active vs. inactive groups). RESULTS: In the physically active group, two SNPs in NR3C2 were significantly associated with lower SBP, and a SNP in SCNN1B was significantly associated with lower SBP and DBP. In the physically inactive group, a SNP in APLNR was associated with lower SBP, a SNP in GNB3 (guanine nucleotide binding protein, ß polypeptide 3) was associated with higher SBP and DBP, and a SNP in BDKRB2 (bradykinin receptor B2) was associated with lower DBP. Cumulative effects in carriers of minor alleles of these SNPs showed reductions of SBP and DBP as large as 8 and 5 mm Hg, respectively, in the active individuals compared to inactive individuals carrying the same number of minor alleles. CONCLUSIONS: We found that physical activity modifies the effects of genetic variants on BP. However, our results also show that active individuals with specific genotypes always have lower BP than inactive individuals with the same genotypes, demonstrating the overall beneficial effects of physical activity on BP.

Polymorphisms in the GNB3 and ADD1 genes and blood pressure in a Chinese population.

A large proportion of the phenotypic variation in blood pressure (BP) appears to be inherited as a polygenic trait. This study examined the association between 12 single nucleotide polymorphisms (SNPs) in the guanine nucleotide binding protein beta polypeptide 3 (GNB3) and adducin 1 alpha (ADD1) genes and systolic (SBP), diastolic (DBP), and mean arterial (MAP) BP. A total of 3,142 individuals from 636 families were recruited from rural north China, and 2,746 met the eligibility criteria for analysis. BP measurements were obtained using a random-zero sphygmomanometer. Genetic variants were determined using SNPlex assays on an automated DNA Sequencer. A mixed linear model was used to estimate the association between each SNP and BP level. After Bonferroni correction, marker rs4963516 of the GNB3 gene remained significantly associated with DBP (corrected P values = 0.006, 0.007 and 0.002 for co-dominant, additive, and recessive models, respectively) and MAP (corrected P values = 0.02, 0.049, and 0.005, respectively). Compared to carriers of the major A allele, CC homozygotes had higher mean DBP (75.81 +/- 0.62 vs. 73.46 +/- 0.25 mmHg, P = 0.0002) and MAP (91.87 +/- 0.68 vs. 89.42 +/- 0.28 mmHg, P = 0.0004) after adjusting for covariates of age, gender, BMI, study site, and room temperature during BP measurement. In summary, these data support a role for the GNB3 gene in BP regulation in the Chinese population. Future studies aimed at replicating these novel findings are warranted.

Novel genetic variants in the alpha-adducin and guanine nucleotide binding protein beta-polypeptide 3 genes and salt sensitivity of blood pressure.

BACKGROUND: We examined the association between 12 single-nucleotide polymorphisms (SNPs) in the alpha-adducin (ADD1) and guanine nucleotide binding protein (G protein) beta-polypeptide 3 (GNB3) genes and systolic (SBP), diastolic (DBP), and mean arterial (MAP) pressure responses to salt intake. METHODS: A 7-day low-sodium (51.3 mmol sodium/day) followed by a 7-day high-sodium intervention (307.8 mmol sodium/day) was conducted among 1,906 Han participants from rural North China. Blood pressure (BP) measurements were obtained at baseline and at the end of each intervention period using a random-zero sphygmomanometer. RESULTS: We identified a significant association between a rare ADD1 variant rs17833172 and SBP, DBP, and MAP responses to high sodium (P values <0.0001) and DBP response to low sodium (P value = 0.002). Participants homozygous for the variant A allele of this marker had SBP, DBP, and MAP responses (95% confidence interval) to high salt of 1.6 (-1.8, 4.9), -0.8 (-5.6, 4.0), and -0.1 (-4.0, 3.9) mm Hg, respectively, vs. corresponding responses of 4.6 (2.5, 6.6), 1.7 (-0.2, 3.6), and 2.7 (0.9, 4.4) mm Hg, respectively, for those who were heterozygous or homozygous for the G allele. In addition, participants with at least one copy of the A allele of SNP rs1129649 of the GNB3 gene had significantly decreased MAP response to low salt compared to homozygotes for the C allele (P value = 0.004) with responses of -3.4 (-3.8, -3.0) vs. -4.2 (-4.6, -3.8) mm Hg, respectively. CONCLUSIONS: These data support a role for the ADD1 and GNB3 genes in BP salt sensitivity. Future studies aimed at replicating these novel findings are warranted.