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2.
Nature ; 616(7958): 747-754, 2023 04.
Article in English | MEDLINE | ID: mdl-37046084

ABSTRACT

Chronic liver disease is a major public health burden worldwide1. Although different aetiologies and mechanisms of liver injury exist, progression of chronic liver disease follows a common pathway of liver inflammation, injury and fibrosis2. Here we examined the association between clonal haematopoiesis of indeterminate potential (CHIP) and chronic liver disease in 214,563 individuals from 4 independent cohorts with whole-exome sequencing data (Framingham Heart Study, Atherosclerosis Risk in Communities Study, UK Biobank and Mass General Brigham Biobank). CHIP was associated with an increased risk of prevalent and incident chronic liver disease (odds ratio = 2.01, 95% confidence interval (95% CI) [1.46, 2.79]; P < 0.001). Individuals with CHIP were more likely to demonstrate liver inflammation and fibrosis detectable by magnetic resonance imaging compared to those without CHIP (odds ratio = 1.74, 95% CI [1.16, 2.60]; P = 0.007). To assess potential causality, Mendelian randomization analyses showed that genetic predisposition to CHIP was associated with a greater risk of chronic liver disease (odds ratio = 2.37, 95% CI [1.57, 3.6]; P < 0.001). In a dietary model of non-alcoholic steatohepatitis, mice transplanted with Tet2-deficient haematopoietic cells demonstrated more severe liver inflammation and fibrosis. These effects were mediated by the NLRP3 inflammasome and increased levels of expression of downstream inflammatory cytokines in Tet2-deficient macrophages. In summary, clonal haematopoiesis is associated with an elevated risk of liver inflammation and chronic liver disease progression through an aberrant inflammatory response.


Subject(s)
Clonal Hematopoiesis , Disease Susceptibility , Hepatitis , Liver Cirrhosis , Animals , Mice , Clonal Hematopoiesis/genetics , Hepatitis/genetics , Inflammation/genetics , Liver Cirrhosis/genetics , Non-alcoholic Fatty Liver Disease/genetics , Odds Ratio , Disease Progression
3.
Circ Genom Precis Med ; 15(6): e003598, 2022 12.
Article in English | MEDLINE | ID: mdl-36215124

ABSTRACT

BACKGROUND: A key goal of precision medicine is to disaggregate common, complex diseases into discrete molecular subtypes. Rare coding variants in the low-density lipoprotein receptor gene (LDLR) are identified in 1% to 2% of coronary artery disease (CAD) patients, defining a molecular subtype with risk driven by hypercholesterolemia. METHODS: To search for additional subtypes, we compared the frequency of rare, predicted loss-of-function and damaging missense variants aggregated within a given gene in 41 081 CAD cases versus 217 115 controls. RESULTS: Rare variants in LDLR were most strongly associated with CAD, present in 1% of cases and associated with 4.4-fold increased CAD risk. A second subtype was characterized by variants in endothelial nitric oxide synthase gene (NOS3), a key enzyme regulating vascular tone, endothelial function, and platelet aggregation. A rare predicted loss-of-function or damaging missense variants in NOS3 was present in 0.6% of cases and associated with 2.42-fold increased risk of CAD (95% CI, 1.80-3.26; P=5.50×10-9). These variants were associated with higher systolic blood pressure (+3.25 mm Hg; [95% CI, 1.86-4.65]; P=5.00×10-6) and increased risk of hypertension (adjusted odds ratio 1.31; [95% CI, 1.14-1.51]; P=2.00×10-4) but not circulating cholesterol concentrations, suggesting that, beyond lipid pathways, nitric oxide synthesis is a key nonlipid driver of CAD risk. CONCLUSIONS: Beyond LDLR, we identified an additional nonlipid molecular subtype of CAD characterized by rare variants in the NOS3 gene.


Subject(s)
Coronary Artery Disease , Hypercholesterolemia , Humans , Coronary Artery Disease/genetics , Polymorphism, Genetic , Nitric Oxide , Cholesterol
5.
JAMA Netw Open ; 5(3): e223849, 2022 03 01.
Article in English | MEDLINE | ID: mdl-35333364

ABSTRACT

Importance: Observational studies have consistently proposed cardiovascular benefits associated with light alcohol consumption, while recent genetic analyses (ie, mendelian randomization studies) have suggested a possible causal link between alcohol intake and increased risk of cardiovascular disease. However, traditional approaches to genetic epidemiology assume a linear association and thus have not fully evaluated dose-response estimates of risk across different levels of alcohol intake. Objectives: To assess the association of habitual alcohol intake with cardiovascular disease risk and to evaluate the direction and relative magnitude of cardiovascular risk associated with different amounts of alcohol consumption. Design, Setting, and Participants: This cohort study used the UK Biobank (2006-2010, follow-up until 2016) to examine confounding in epidemiologic associations between alcohol intake and cardiovascular diseases. Using both traditional (ie, linear) and nonlinear mendelian randomization, potential associations between alcohol consumption and cardiovascular diseases (eg, hypertension and coronary artery disease) as well as corresponding association shapes were assessed. Data analysis was conducted from July 2019 to January 2022. Exposures: Genetic predisposition to alcohol intake. Main Outcomes and Measures: The association between alcohol consumption and cardiovascular diseases, including hypertension, coronary artery disease, myocardial infarction, stroke, heart failure, and atrial fibrillation. Results: This study included 371 463 participants (mean [SD] age, 57.0 [7.9] years; 172 400 [46%] men), who consumed a mean (SD) 9.2 (10.6) standard drinks per week. Overall, 121 708 participants (33%) had hypertension. Light to moderate alcohol consumption was associated with healthier lifestyle factors, adjustment for which attenuated the cardioprotective epidemiologic associations with modest intake. In linear mendelian randomization analyses, a 1-SD increase in genetically predicted alcohol consumption was associated with 1.3-fold (95% CI, 1.2-1.4) higher risk of hypertension (P < .001) and 1.4-fold (95% CI, 1.1-1.8) higher risk of coronary artery disease (P = .006). Nonlinear mendelian randomization analyses suggested nonlinear associations between alcohol consumption and both hypertension and coronary artery disease: light alcohol intake was associated with minimal increases in cardiovascular risk, whereas heavier consumption was associated with exponential increases in risk of both clinical and subclinical cardiovascular disease. Conclusions and Relevance: In this cohort study, coincident, favorable lifestyle factors attenuated the observational benefits of modest alcohol intake. Genetic epidemiology suggested that alcohol consumption of all amounts was associated with increased cardiovascular risk, but marked risk differences exist across levels of intake, including those accepted by current national guidelines.


Subject(s)
Cardiovascular Diseases , Coronary Artery Disease , Hypertension , Alcohol Drinking/adverse effects , Alcohol Drinking/epidemiology , Cardiovascular Diseases/etiology , Cohort Studies , Coronary Artery Disease/complications , Humans , Hypertension/complications , Male , Middle Aged
6.
Patterns (N Y) ; 2(12): 100364, 2021 Dec 10.
Article in English | MEDLINE | ID: mdl-34950898

ABSTRACT

Current cardiovascular risk assessment tools use a small number of predictors. Here, we study how machine learning might: (1) enable principled selection from a large multimodal set of candidate variables and (2) improve prediction of incident coronary artery disease (CAD) events. An elastic net-based Cox model (ML4HEN-COX) trained and evaluated in 173,274 UK Biobank participants selected 51 predictors from 13,782 candidates. Beyond most traditional risk factors, ML4HEN-COX selected a polygenic score, waist circumference, socioeconomic deprivation, and several hematologic indices. A more than 30-fold gradient in 10-year risk estimates was noted across ML4HEN-COX quintiles, ranging from 0.25% to 7.8%. ML4HEN-COX improved discrimination of incident CAD (C-statistic = 0.796) compared with the Framingham risk score, pooled cohort equations, and QRISK3 (range 0.754-0.761). This approach to variable selection and model assessment is readily generalizable to a broad range of complex datasets and disease endpoints.

7.
Cell Genom ; 1(3)2021 Dec 08.
Article in English | MEDLINE | ID: mdl-34957434

ABSTRACT

Excess liver fat, called hepatic steatosis, is a leading risk factor for end-stage liver disease and cardiometabolic diseases but often remains undiagnosed in clinical practice because of the need for direct imaging assessments. We developed an abdominal MRI-based machine-learning algorithm to accurately estimate liver fat (correlation coefficients, 0.97-0.99) from a truth dataset of 4,511 middle-aged UK Biobank participants, enabling quantification in 32,192 additional individuals. 17% of participants had predicted liver fat levels indicative of steatosis, and liver fat could not have been reliably estimated based on clinical factors such as BMI. A genome-wide association study of common genetic variants and liver fat replicated three known associations and identified five newly associated variants in or near the MTARC1, ADH1B, TRIB1, GPAM, and MAST3 genes (p < 3 × 10-8). A polygenic score integrating these eight genetic variants was strongly associated with future risk of chronic liver disease (hazard ratio > 1.32 per SD score, p < 9 × 10-17). Rare inactivating variants in the APOB or MTTP genes were identified in 0.8% of individuals with steatosis and conferred more than 6-fold risk (p < 2 × 10-5), highlighting a molecular subtype of hepatic steatosis characterized by defective secretion of apolipoprotein B-containing lipoproteins. We demonstrate that our imaging-based machine-learning model accurately estimates liver fat and may be useful in epidemiological and genetic studies of hepatic steatosis.

9.
Cell Rep Med ; 2(11): 100437, 2021 11 16.
Article in English | MEDLINE | ID: mdl-34841290

ABSTRACT

Non-alcoholic fatty liver disease (NAFLD) is a complex disease linked to several chronic diseases. We aimed at identifying genetic variants associated with NAFLD and evaluating their functional consequences. We performed a genome-wide meta-analysis of 4 cohorts of electronic health record-documented NAFLD in participants of European ancestry (8,434 cases and 770,180 controls). We identify 5 potential susceptibility loci for NAFLD (located at or near GCKR, TR1B1, MAU2/TM6SF2, APOE, and PNPLA3). We also report a potentially causal effect of lower LPL expression in adipose tissue on NAFLD susceptibility and an effect of the FTO genotype on NAFLD. Positive genetic correlations between NAFLD and cardiometabolic diseases and risk factors such as body fat accumulation/distribution, lipoprotein-lipid levels, insulin resistance, and coronary artery disease and negative genetic correlations with parental lifespan, socio-economic status, and acetoacetate levels are observed. This large GWAS meta-analysis reveals insights into the genetic architecture of NAFLD.


Subject(s)
Electronic Health Records , Genetic Predisposition to Disease , Genome-Wide Association Study , Non-alcoholic Fatty Liver Disease/genetics , Genetic Variation , Humans , Linkage Disequilibrium/genetics , Lipoprotein Lipase/genetics , Obesity/genetics , Phenotype
11.
J Hepatol ; 74(1): 20-30, 2021 01.
Article in English | MEDLINE | ID: mdl-32882372

ABSTRACT

BACKGROUND & AIMS: A common genetic variant near MBOAT7 (rs641738C>T) has been previously associated with hepatic fat and advanced histology in NAFLD; however, these findings have not been consistently replicated in the literature. We aimed to establish whether rs641738C>T is a risk factor across the spectrum of NAFLD and to characterise its role in the regulation of related metabolic phenotypes through a meta-analysis. METHODS: We performed a meta-analysis of studies with data on the association between rs641738C>T genotype and liver fat, NAFLD histology, and serum alanine aminotransferase (ALT), lipids or insulin. These included directly genotyped studies and population-level data from genome-wide association studies (GWAS). We performed a random effects meta-analysis using recessive, additive and dominant genetic models. RESULTS: Data from 1,066,175 participants (9,688 with liver biopsies) across 42 studies were included in the meta-analysis. rs641738C>T was associated with higher liver fat on CT/MRI (+0.03 standard deviations [95% CI 0.02-0.05], pz = 4.8×10-5) and diagnosis of NAFLD (odds ratio [OR] 1.17 [95% CI 1.05-1.3], pz = 0.003) in Caucasian adults. The variant was also positively associated with presence of advanced fibrosis (OR 1.22 [95% CI 1.03-1.45], pz = 0.021) in Caucasian adults using a recessive model of inheritance (CC + CT vs. TT). Meta-analysis of data from previous GWAS found the variant to be associated with higher ALT (pz = 0.002) and lower serum triglycerides (pz = 1.5×10-4). rs641738C>T was not associated with fasting insulin and no effect was observed in children with NAFLD. CONCLUSIONS: Our study validates rs641738C>T near MBOAT7 as a risk factor for the presence and severity of NAFLD in individuals of European descent. LAY SUMMARY: Fatty liver disease is a common condition where fat builds up in the liver, which can cause liver inflammation and scarring (including 'cirrhosis'). It is closely linked to obesity and diabetes, but some genes are also thought to be important. We did this study to see whether one specific change ('variant') in one gene ('MBOAT7') was linked to fatty liver disease. We took data from over 40 published studies and found that this variant near MBOAT7 is linked to more severe fatty liver disease. This means that drugs designed to work on MBOAT7 could be useful for treating fatty liver disease.


Subject(s)
Acyltransferases/genetics , Liver Cirrhosis , Liver/pathology , Membrane Proteins/genetics , Non-alcoholic Fatty Liver Disease , Alanine Transaminase/blood , Drug Discovery , Genetic Predisposition to Disease , Humans , Liver Cirrhosis/metabolism , Liver Cirrhosis/pathology , Non-alcoholic Fatty Liver Disease/drug therapy , Non-alcoholic Fatty Liver Disease/genetics , Polymorphism, Single Nucleotide
12.
Gastroenterology ; 160(5): 1620-1633.e13, 2021 04.
Article in English | MEDLINE | ID: mdl-33310085

ABSTRACT

BACKGROUND & AIMS: In contrast to most other common diseases, few genetic variants have been identified that impact risk of cirrhosis. We aimed to identify new genetic variants that predispose to cirrhosis, to test whether such variants, aggregated into a polygenic score, enable genomic risk stratification, and to test whether alcohol intake or body mass index interacts with polygenic predisposition. METHODS: We conducted a multi-trait genome-wide association study combining cirrhosis and alanine aminotransferase levels performed in 5 discovery studies (UK Biobank, Vanderbilt BioVU, Atherosclerosis Risk in Communities study, and 2 case-control studies including 4829 individuals with cirrhosis and 72,705 controls and 362,539 individuals with alanine aminotransferase levels). Identified variants were replicated in 3 studies (Partners HealthCare Biobank, FinnGen, and Biobank Japan including 3554 individuals with cirrhosis and 343,826 controls). A polygenic score was tested in Partners HealthCare Biobank. RESULTS: Five previously reported and 7 newly identified genetic variants were associated with cirrhosis in both the discovery studies multi-trait genome-wide association study (P < 5 × 10-8) and the replication studies (P < .05), including a missense variant in the APOE gene and a noncoding variant near EFN1A. These 12 variants were used to generate a polygenic score. Among Partners HealthCare Biobank individuals, high polygenic score-defined as the top quintile of the distribution-was associated with significantly increased risk of cirrhosis (odds ratio, 2.26; P < .001) and related comorbidities compared with the lowest quintile. Risk was even more pronounced among those with extreme polygenic risk (top 1% of the distribution, odds ratio, 3.16; P < .001). The impact of extreme polygenic risk was substantially more pronounced in those with elevated alcohol consumption or body mass index. Modeled as risk by age 75 years, probability of cirrhosis with extreme polygenic risk was 13.7%, 20.1%, and 48.2% among individuals with no or modest, moderate, and increased alcohol consumption, respectively (Pinteraction < .001). Similarly, probability among those with extreme polygenic risk was 6.5%, 10.3%, and 19.5% among individuals with normal weight, overweight, and obesity, respectively (Pinteraction < .001). CONCLUSIONS: Twelve independent genetic variants, 7 of which are newly identified in this study, conferred risk for cirrhosis. Aggregated into a polygenic score, these variants identified a subset of the population at substantially increased risk who are most susceptible to the hepatotoxic effects of excess alcohol consumption or obesity.


Subject(s)
Gene-Environment Interaction , Genetic Variation , Liver Cirrhosis/genetics , Adult , Age Factors , Aged , Alcohol Drinking/adverse effects , Alcohol Drinking/epidemiology , Case-Control Studies , Comorbidity , Female , Genetic Predisposition to Disease , Genome-Wide Association Study , Humans , Liver Cirrhosis/diagnosis , Liver Cirrhosis/epidemiology , Male , Middle Aged , Multifactorial Inheritance , Obesity/epidemiology , Phenotype , Risk Assessment , Risk Factors
13.
Nature ; 586(7831): 769-775, 2020 10.
Article in English | MEDLINE | ID: mdl-33057200

ABSTRACT

Myeloproliferative neoplasms (MPNs) are blood cancers that are characterized by the excessive production of mature myeloid cells and arise from the acquisition of somatic driver mutations in haematopoietic stem cells (HSCs). Epidemiological studies indicate a substantial heritable component of MPNs that is among the highest known for cancers1. However, only a limited number of genetic risk loci have been identified, and the underlying biological mechanisms that lead to the acquisition of MPNs remain unclear. Here, by conducting a large-scale genome-wide association study (3,797 cases and 1,152,977 controls), we identify 17 MPN risk loci (P < 5.0 × 10-8), 7 of which have not been previously reported. We find that there is a shared genetic architecture between MPN risk and several haematopoietic traits from distinct lineages; that there is an enrichment for MPN risk variants within accessible chromatin of HSCs; and that increased MPN risk is associated with longer telomere length in leukocytes and other clonal haematopoietic states-collectively suggesting that MPN risk is associated with the function and self-renewal of HSCs. We use gene mapping to identify modulators of HSC biology linked to MPN risk, and show through targeted variant-to-function assays that CHEK2 and GFI1B have roles in altering the function of HSCs to confer disease risk. Overall, our results reveal a previously unappreciated mechanism for inherited MPN risk through the modulation of HSC function.


Subject(s)
Genetic Predisposition to Disease/genetics , Hematopoietic Stem Cells/pathology , Myeloproliferative Disorders/genetics , Myeloproliferative Disorders/pathology , Neoplasms/genetics , Neoplasms/pathology , Cell Lineage/genetics , Cell Self Renewal , Checkpoint Kinase 2/genetics , Female , Humans , Leukocytes/pathology , Male , Proto-Oncogene Proteins/genetics , Repressor Proteins/genetics , Risk , Telomere Homeostasis
14.
Circ Genom Precis Med ; 13(5): 417-423, 2020 10.
Article in English | MEDLINE | ID: mdl-32862661

ABSTRACT

BACKGROUND: Familial sitosterolemia is a rare Mendelian disorder characterized by hyperabsorption and decreased biliary excretion of dietary sterols. Affected individuals typically have complete genetic deficiency-homozygous loss-of-function (LoF) variants-in the ABCG5 or ABCG8 genes and have substantially elevated plasma sitosterol and LDL (low-density lipoprotein) cholesterol (LDL-C) levels. The impact of partial genetic deficiency of ABCG5 or ABCG8-as occurs in heterozygous carriers of LoF variants-on LDL-C and risk of coronary artery disease (CAD) has remained uncertain. METHODS: We first recruited 9 sitosterolemia families, identified causative LoF variants in ABCG5 or ABCG8, and evaluated the associations of these ABCG5 or ABCG8 LoF variants with plasma phytosterols and lipid levels. We next assessed for LoF variants in ABCG5 or ABCG8 in CAD cases (n=29 321) versus controls (n=357 326). We tested the association of rare LoF variants in ABCG5 or ABCG8 with blood lipids and risk for CAD. Rare LoF variants were defined as protein-truncating variants with minor allele frequency <0.1% in ABCG5 or ABCG8. RESULTS: In sitosterolemia families, 7 pedigrees harbored causative LoF variants in ABCG5 and 2 pedigrees in ABCG8. Homozygous LoF variants in either ABCG5 or ABCG8 led to marked elevations in sitosterol and LDL-C. Of those sitosterolemia families, heterozygous carriers of ABCG5 LoF variants exhibited increased sitosterol and LDL-C levels compared with noncarriers. Within large-scale CAD case-control cohorts, prevalence of rare LoF variants in ABCG5 and in ABCG8 was ≈0.1% each. ABCG5 heterozygous LoF variant carriers had significantly elevated LDL-C levels (25 mg/dL [95% CI, 14-35]; P=1.1×10-6) and were at 2-fold increased risk of CAD (odds ratio, 2.06 [95% CI, 1.27-3.35]; P=0.004). By contrast, ABCG8 heterozygous LoF carrier status was not associated with increased LDL-C or risk of CAD. CONCLUSIONS: Although familial sitosterolemia is traditionally considered as a recessive disorder, we observed that heterozygous carriers of an LoF variant in ABCG5 had significantly increased sitosterol and LDL-C levels and a 2-fold increase in risk of CAD.


Subject(s)
ATP Binding Cassette Transporter, Subfamily G, Member 5/genetics , Coronary Artery Disease/genetics , Lipoproteins/genetics , ATP Binding Cassette Transporter, Subfamily G, Member 8/genetics , Adult , Case-Control Studies , Cholesterol, LDL/blood , Coronary Artery Disease/diagnosis , Female , Heterozygote , Humans , Hypercholesterolemia/genetics , Hypercholesterolemia/pathology , Intestinal Diseases/genetics , Intestinal Diseases/pathology , Lipid Metabolism, Inborn Errors/genetics , Lipid Metabolism, Inborn Errors/pathology , Loss of Function Mutation , Male , Middle Aged , Odds Ratio , Phytosterols/adverse effects , Phytosterols/genetics , Risk Factors , Sitosterols/blood
15.
PLoS Genet ; 16(4): e1008629, 2020 04.
Article in English | MEDLINE | ID: mdl-32282858

ABSTRACT

Analyzing 12,361 all-cause cirrhosis cases and 790,095 controls from eight cohorts, we identify a common missense variant in the Mitochondrial Amidoxime Reducing Component 1 gene (MARC1 p.A165T) that associates with protection from all-cause cirrhosis (OR 0.91, p = 2.3*10-11). This same variant also associates with lower levels of hepatic fat on computed tomographic imaging and lower odds of physician-diagnosed fatty liver as well as lower blood levels of alanine transaminase (-0.025 SD, 3.7*10-43), alkaline phosphatase (-0.025 SD, 1.2*10-37), total cholesterol (-0.030 SD, p = 1.9*10-36) and LDL cholesterol (-0.027 SD, p = 5.1*10-30) levels. We identified a series of additional MARC1 alleles (low-frequency missense p.M187K and rare protein-truncating p.R200Ter) that also associated with lower cholesterol levels, liver enzyme levels and reduced risk of cirrhosis (0 cirrhosis cases for 238 R200Ter carriers versus 17,046 cases of cirrhosis among 759,027 non-carriers, p = 0.04) suggesting that deficiency of the MARC1 enzyme may lower blood cholesterol levels and protect against cirrhosis.


Subject(s)
Fatty Liver/genetics , Fatty Liver/prevention & control , Genetic Predisposition to Disease , Liver Cirrhosis/genetics , Liver Cirrhosis/prevention & control , Mitochondrial Proteins/genetics , Mutation, Missense/genetics , Oxidoreductases/genetics , Alleles , Cholesterol, LDL/blood , Coronary Artery Disease/genetics , Datasets as Topic , Fatty Liver/blood , Fatty Liver/enzymology , Female , Homozygote , Humans , Liver/enzymology , Liver Cirrhosis/blood , Liver Cirrhosis/enzymology , Liver Cirrhosis, Alcoholic/blood , Liver Cirrhosis, Alcoholic/enzymology , Liver Cirrhosis, Alcoholic/genetics , Liver Cirrhosis, Alcoholic/prevention & control , Loss of Function Mutation/genetics , Male , Middle Aged
17.
Obes Res Clin Pract ; 14(1): 99-102, 2020.
Article in English | MEDLINE | ID: mdl-31839475

ABSTRACT

BACKGROUND: Obesity is prevalent in Indigenous populations who exhibit significant differences in body fat composition. While excess regional adiposity can be partially inferred from clinical measurements, noninvasive imaging allows for direct quantification of specific fat depots. Epicardial fat is a visceral adipose tissue that has been strongly associated with cardiometabolic disease in other populations. However, this ectopic fat depot has yet to be characterized in Indigenous populations. METHODS: We studied 100 individuals matched for ethnicity (Indigenous Australian and Caucasian descent), age, gender, and body mass index. Epicardial and subcutaneous adipose tissue volumes was quantified with computed tomography. Associations of ethnicity and adiposity measures were assessed using linear regression. RESULTS: Indigenous individuals had significantly greater epicardial fat volumes compared to non-Indigenous individuals (95.8±37.5 vs 54.1±27.6cm3, p<0.001). In contrast, subcutaneous fat volumes were comparable in Indigenous compared to non-Indigenous individuals (22.1±15.1 vs 20.3±13.5cm3, p=0.54). Sequential adjustment for age, gender, comorbidities, biochemical parameters, and medication use did not attenuate the association between Indigenous ethnicity and greater epicardial fat volume in multivariable models (B=43.0, p<0.001). Furthermore, this association did not materially change with the inclusion of various adiposity measures, such as body mass index, subcutaneous adipose tissue, or weight. CONCLUSIONS: Indigenous individuals have significantly greater epicardial fat, but similar subcutaneous fat volumes, compared to non-Indigenous individuals. This finding extends previous observations on body fat composition differences in these individuals, and supports the possibility that epicardial fat and other visceral adipose depots may be contributing to the greater burden of cardiovascular disease in Indigenous populations.


Subject(s)
Metabolic Syndrome/ethnology , Native Hawaiian or Other Pacific Islander/statistics & numerical data , Pericardium/pathology , Subcutaneous Fat/pathology , White People/statistics & numerical data , Adult , Australia/ethnology , Body Mass Index , Cardiometabolic Risk Factors , Coronary Angiography , Female , Humans , Male , Middle Aged , Multidetector Computed Tomography , Pericardium/diagnostic imaging , Subcutaneous Fat/diagnostic imaging
18.
Arterioscler Thromb Vasc Biol ; 39(6): 1253-1261, 2019 06.
Article in English | MEDLINE | ID: mdl-31070453

ABSTRACT

Objective- Arterial stiffness index (ASI) is independently associated with blood pressure (BP) and coronary artery disease (CAD) epidemiologically. However, it is unknown whether these associations represent causal relationships. Here, we assess whether genetic predisposition to increased ASI is associated with elevated BP and CAD risk. Approach and Results- We first performed a large-scale epidemiological association of finger photoplethysmography-derived ASI in the UK Biobank, finding significant associations with systolic BP (ß=0.55 mm Hg; [95% CI, 0.45-0.65]; P=5.77×10-24; N=137 858), diastolic BP (ß=1.05 mm Hg; [95% CI, 0.99-1.11]; P=7.27×10-272; N=137 862), and incident CAD (hazard ratio, 1.08; [95% CI, 1.04-1.11]; P=1.5×10-6; N=3692 cases, 126 615 controls) in multivariable models. We then performed an ASI genome-wide association study analysis in 131 686 participants from the UK Biobank. Across participants not in the ASI genome-wide association study, a 6-variant ASI polygenic risk score was calculated. Each SD increase in genetic ASI was associated with systolic BP (ß=4.63 mm Hg; [95% CI, 2.1-7.2]; P=3.37×10-4; N=208 897), and diastolic BP (ß=2.61 mm Hg; [95% CI, 1.2-4.0]; P=2.85×10-4; N=208 897); however, no association was observed with incident CAD (hazard ratio, 1.12; [95% CI, 0.55-2.3]; P=0.75; N=223 061; 7534 cases). The lack of CAD association observed was replicated among 184 305 participants (60 810 cases) from the CARDIOGRAMplusC4D (Coronary Artery Disease Genetics Consortium; odds ratio, 0.56; [95% CI, 0.26-1.24]; P=0.15). Conclusions- Our data support the conclusion that finger photoplethysmography-derived ASI is an independent, genetically causal risk factor for BP, but do not support the notion that ASI is a suitable surrogate for CAD risk.


Subject(s)
Blood Pressure/genetics , Coronary Artery Disease/genetics , Coronary Artery Disease/physiopathology , Fingers/blood supply , Photoplethysmography , Polymorphism, Single Nucleotide , Vascular Stiffness/genetics , Case-Control Studies , Coronary Artery Disease/diagnosis , Coronary Artery Disease/epidemiology , Female , Genetic Predisposition to Disease , Genome-Wide Association Study , Humans , Incidence , Male , Middle Aged , Phenotype , Predictive Value of Tests , Risk Assessment , Risk Factors , United Kingdom/epidemiology
19.
J Hypertens ; 37(1): 16-23, 2019 01.
Article in English | MEDLINE | ID: mdl-30499920

ABSTRACT

OBJECTIVE: To assess the clinical relevance of regression to the mean for clinical trials and clinical practice. METHODS: MEDLINE was searched until February 2018 for randomized trials of BP lowering with over 1000 patient-years follow-up per group. We estimated baseline mean BP, follow-up mean (usual) BP amongst patients grouped by 10 mmHg strata of baseline BP, and assessed effects of BP lowering on coronary heart disease (CHD) and stroke according to these BP levels. RESULTS: Eighty-six trials (349 488 participants), with mean follow-up of 3.7 years, were included. Most mean BP change was because of regression to the mean rather than treatment. At high baseline BP levels, even after rigorous hypertension diagnosis, downwards regression to the mean caused much of the fall in BP. At low baseline BP levels, upwards regression to the mean increased BP levels, even in treatment groups. Overall, a BP reduction of 6/3 mmHg lowered CHD by 14% (95% CI 11-17%) and stroke by 18% (15-22%), and these treatment effects occurred at follow-up BP levels much closer to the mean than baseline BP levels. In particular, more evidence was available in the SBP 130-139 mmHg range than any other range. Benefits were apparent in numerous high-risk patient groups with baseline mean SBP less than 140 mmHg. CONCLUSION: Clinical practice should focus less on pretreatment BP levels, which rarely predict future untreated BP levels or rule out capacity to benefit from BP lowering in high cardiovascular risk patients. Instead, focus should be on prompt, empirical treatment to maintain lower BP for those with high BP and/or high risk.


Subject(s)
Antihypertensive Agents/therapeutic use , Hypertension , Blood Pressure/physiology , Humans , Hypertension/complications , Hypertension/drug therapy , Hypertension/epidemiology , Randomized Controlled Trials as Topic , Regression Analysis
20.
Diabetes ; 68(1): 226-234, 2019 01.
Article in English | MEDLINE | ID: mdl-30389748

ABSTRACT

A genetic predisposition to higher waist-to-hip ratio adjusted for BMI (WHRadjBMI), a measure of body fat distribution, associates with increased risk for type 2 diabetes. We conducted an exome-wide association study of coding variation in UK Biobank (405,569 individuals) to identify variants that lower WHRadjBMI and protect against type 2 diabetes. We identified four variants in the gene ACVR1C (encoding the activin receptor-like kinase 7 receptor expressed on adipocytes and pancreatic ß-cells), which independently associated with reduced WHRadjBMI: Asn150His (-0.09 SD, P = 3.4 × 10-17), Ile195Thr (-0.15 SD, P = 1.0 × 10-9), Ile482Val (-0.019 SD, P = 1.6 × 10-5), and rs72927479 (-0.035 SD, P = 2.6 × 10-12). Carriers of these variants exhibited reduced percent abdominal fat in DEXA imaging. Pooling across all four variants, a 0.2 SD decrease in WHRadjBMI through ACVR1C was associated with a 30% lower risk of type 2 diabetes (odds ratio [OR] 0.70, 95% CI 0.63, 0.77; P = 5.6 × 10-13). In an analysis of exome sequences from 55,516 individuals, carriers of predicted damaging variants in ACVR1C were at 54% lower risk of type 2 diabetes (OR 0.46, 95% CI 0.27, 0.81; P = 0.006). These findings indicate that variants predicted to lead to loss of ACVR1C gene function influence body fat distribution and protect from type 2 diabetes.


Subject(s)
Activin Receptors, Type I/genetics , Diabetes Mellitus, Type 2/genetics , Sequence Analysis, DNA/methods , Algorithms , Exome/genetics , Genetic Predisposition to Disease/genetics , Genome-Wide Association Study , Humans
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