Individuality and ethnicity eclipse a short-term dietary intervention in shaping microbiomes and viromes.

Many diseases linked with ethnic health disparities associate with changes in microbial communities in the United States, but the causes and persistence of ethnicity-associated microbiome variation are not understood. For instance, microbiome studies that strictly control for diet across ethnically diverse populations are lacking. Here, we performed multiomic profiling over a 9-day period that included a 4-day controlled vegetarian diet intervention in a defined geographic location across 36 healthy Black and White females of similar age, weight, habitual diets, and health status. We demonstrate that individuality and ethnicity account for roughly 70% to 88% and 2% to 10% of taxonomic variation, respectively, eclipsing the effects a short-term diet intervention in shaping gut and oral microbiomes and gut viromes. Persistent variation between ethnicities occurs for microbial and viral taxa and various metagenomic functions, including several gut KEGG orthologs, oral carbohydrate active enzyme categories, cluster of orthologous groups of proteins, and antibiotic-resistant gene categories. In contrast to the gut and oral microbiome data, the urine and plasma metabolites tend to decouple from ethnicity and more strongly associate with diet. These longitudinal, multiomic profiles paired with a dietary intervention illuminate previously unrecognized associations of ethnicity with metagenomic and viromic features across body sites and cohorts within a single geographic location, highlighting the importance of accounting for human microbiome variation in research, health determinants, and eventual therapies. Trial Registration: ClinicalTrials.gov ClinicalTrials.gov Identifier: NCT03314194.

Gut Microbiota and Microbial Metabolism in Early Risk of Cardiometabolic Disease.

Cardiometabolic disease comprises cardiovascular and metabolic dysfunction and underlies the leading causes of morbidity and mortality, both within the United States and worldwide. Commensal microbiota are implicated in the development of cardiometabolic disease. Evidence suggests that the microbiome is relatively variable during infancy and early childhood, becoming more fixed in later childhood and adulthood. Effects of microbiota, both during early development, and in later life, may induce changes in host metabolism that modulate risk mechanisms and predispose toward the development of cardiometabolic disease. In this review, we summarize the factors that influence gut microbiome composition and function during early life and explore how changes in microbiota and microbial metabolism influence host metabolism and cardiometabolic risk throughout life. We highlight limitations in current methodology and approaches and outline state-of-the-art advances, which are improving research and building toward refined diagnosis and treatment options in microbiome-targeted therapies.

Microbiome-associated human genetic variants impact phenome-wide disease risk.

Human genetic variation associates with the composition of the gut microbiome, yet its influence on clinical traits remains largely unknown. We analyzed the consequences of nearly a thousand gut microbiome-associated variants (MAVs) on phenotypes reported in electronic health records from tens of thousands of individuals. We discovered and replicated associations of MAVs with neurological, metabolic, digestive, and circulatory diseases. Five significant MAVs in these categories correlate with the relative abundance of microbes down to the strain level. We also demonstrate that these relationships are independently observed and concordant with microbe by disease associations reported in case-control studies. Moreover, a selective sweep and population differentiation impacted some disease-linked MAVs. Combined, these findings establish triad relationships among the human genome, microbiome, and disease. Consequently, human genetic influences may offer opportunities for precision diagnostics of microbiome-associated diseases but also highlight the relevance of genetic background for microbiome modulation and therapeutics.

The consumption of animal products is associated with plasma levels of alpha-aminoadipic acid (2-AAA).

BACKGROUND AND AIMS: The cardiometabolic disease-associated metabolite, alpha-aminoadipic acid (2-AAA) is formed from the breakdown of the essential dietary amino acid lysine. However, it was not known whether elevated plasma levels of 2-AAA are related to dietary nutrient intake. We aimed to determine whether diet is a determinant of circulating 2-AAA in healthy individuals, and whether 2-AAA is altered in response to dietary modification. METHODS AND RESULTS: We investigated the association between 2-AAA and dietary nutrient intake in a cross-sectional study of healthy individuals (N = 254). We then performed a randomized cross-over dietary intervention trial to investigate the effect of lysine supplementation (1 week) on 2-AAA in healthy individuals (N = 40). We further assessed the effect of a vegetarian diet on 2-AAA in a short-term (4-day) dietary intervention trial in healthy omnivorous women (N = 35). We found that self-reported dietary intake of animal products, including meat, poultry, and seafood, was associated with higher plasma 2-AAA cross-sectionally (P < 0.0001). Supplementary dietary lysine (5g/day) caused no significant increase in plasma 2-AAA; however, plasma 2-AAA was altered by general dietary modification. Further, plasma 2-AAA was significantly reduced by a short-term vegetarian diet (P = 0.003). CONCLUSION: We identified associations between plasma 2-AAA and consumption of animal products, which were validated in a vegetarian dietary intervention trial, but not in a trial designed to specifically increase the 2-AAA amino acid precursor lysine. Further studies are warranted to investigate whether implementation of a vegetarian diet improves cardiometabolic risk in individuals with elevated 2-AAA.

Heart Disease and Stroke Statistics-2022 Update: A Report From the American Heart Association.

BACKGROUND: The American Heart Association, in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs). METHODS: The American Heart Association, through its Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update. The 2022 Statistical Update is the product of a full year's worth of effort by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. This year's edition includes data on the monitoring and benefits of cardiovascular health in the population and an enhanced focus on social determinants of health, adverse pregnancy outcomes, vascular contributions to brain health, and the global burden of cardiovascular disease and healthy life expectancy. RESULTS: Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics. CONCLUSIONS: The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Heart Disease and Stroke Statistics-2021 Update: A Report From the American Heart Association.

BACKGROUND: The American Heart Association, in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs). METHODS: The American Heart Association, through its Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update. The 2021 Statistical Update is the product of a full year's worth of effort by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. This year's edition includes data on the monitoring and benefits of cardiovascular health in the population, an enhanced focus on social determinants of health, adverse pregnancy outcomes, vascular contributions to brain health, the global burden of cardiovascular disease, and further evidence-based approaches to changing behaviors related to cardiovascular disease. RESULTS: Each of the 27 chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics. CONCLUSIONS: The Statistical Update represents a critical resource for the lay public, policy makers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Genome-wide analysis identifies novel susceptibility loci for myocardial infarction.

AIMS: While most patients with myocardial infarction (MI) have underlying coronary atherosclerosis, not all patients with coronary artery disease (CAD) develop MI. We sought to address the hypothesis that some of the genetic factors which establish atherosclerosis may be distinct from those that predispose to vulnerable plaques and thrombus formation. METHODS AND RESULTS: We carried out a genome-wide association study for MI in the UK Biobank (n∼472 000), followed by a meta-analysis with summary statistics from the CARDIoGRAMplusC4D Consortium (n∼167 000). Multiple independent replication analyses and functional approaches were used to prioritize loci and evaluate positional candidate genes. Eight novel regions were identified for MI at the genome wide significance level, of which effect sizes at six loci were more robust for MI than for CAD without the presence of MI. Confirmatory evidence for association of a locus on chromosome 1p21.3 harbouring choline-like transporter 3 (SLC44A3) with MI in the context of CAD, but not with coronary atherosclerosis itself, was obtained in Biobank Japan (n∼165 000) and 16 independent angiography-based cohorts (n∼27 000). Follow-up analyses did not reveal association of the SLC44A3 locus with CAD risk factors, biomarkers of coagulation, other thrombotic diseases, or plasma levels of a broad array of metabolites, including choline, trimethylamine N-oxide, and betaine. However, aortic expression of SLC44A3 was increased in carriers of the MI risk allele at chromosome 1p21.3, increased in ischaemic (vs. non-diseased) coronary arteries, up-regulated in human aortic endothelial cells treated with interleukin-1ß (vs. vehicle), and associated with smooth muscle cell migration in vitro. CONCLUSIONS: A large-scale analysis comprising ∼831 000 subjects revealed novel genetic determinants of MI and implicated SLC44A3 in the pathophysiology of vulnerable plaques.

Heart Disease and Stroke Statistics-2020 Update: A Report From the American Heart Association.

BACKGROUND: The American Heart Association, in conjunction with the National Institutes of Health, annually reports on the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs). METHODS: The American Heart Association, through its Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update. The 2020 Statistical Update is the product of a full year's worth of effort by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. This year's edition includes data on the monitoring and benefits of cardiovascular health in the population, metrics to assess and monitor healthy diets, an enhanced focus on social determinants of health, a focus on the global burden of cardiovascular disease, and further evidence-based approaches to changing behaviors, implementation strategies, and implications of the American Heart Association's 2020 Impact Goals. RESULTS: Each of the 26 chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics. CONCLUSIONS: The Statistical Update represents a critical resource for the lay public, policy makers, media professionals, clinicians, healthcare administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Gut Microbiota-Derived Short-Chain Fatty Acids Facilitate Microbiota:Host Cross talk and Modulate Obesity and Hypertension.

PURPOSE OF REVIEW: The purpose of this review is to summarize the evidence supporting a role of short-chain fatty acids (SCFAs) as messengers facilitating cross talk between the host and gut microbiota and discuss the effects of altered SCFA signaling in obesity and hypertension. RECENT FINDINGS: Recent evidence suggests there to be a significant contribution of gut microbiota-derived SCFAs to microbe:host communication and host metabolism. SCFA production within the intestine modulates intestinal pH, microbial composition, and intestinal barrier integrity. SCFA signaling through host receptors, such as PPARγ and GPCRs, modulates host health and disease physiology. Alterations in SCFA signaling and downstream effects on inflammation are implicated in the development of obesity and hypertension. SCFAs are crucial components of the holobiont relationship; in the proper environment, they support normal gut, immune, and metabolic function. Dysregulation of microbial SCFA signaling affects downstream host metabolism, with implications in obesity and hypertension.

A metabolome and microbiome wide association study of healthy eating index points to the mechanisms linking dietary pattern and metabolic status.

BACKGROUND: Healthy eating index (HEI), a measure of diet quality, associates with metabolic health outcomes; however, the molecular basis is unclear. We conducted a multi-omic study to examine whether HEI associates with the circulatory and gut metabolome and investigated the gut microbiome-HEI interaction on circulating and gut metabolites. METHODS: Through a cross-sectional study, we evaluated diet quality in healthy individuals [the ABO Glycoproteomics in Platelets and Endothelial Cells (ABO) Study, n = 73], metabolites (measured at Metabolon Inc.) in plasma (n = 800) and gut (n = 767) and the gut microbiome at enterotype and microbial taxa (n = 296) levels. Pathway analysis was conducted using Metaboanalyst 4.0. We performed multi-variable linear regression to explore both the HEI-metabolites and HEI-microbiome associations and how metabolites were affected by the HEI-microbiome interaction. In the Fish oils and Adipose Inflammation Reduction (FAIR) Study (n = 25), analyses on HEI and plasma metabolites were replicated. Estimates of findings from both studies were pooled in random-effects meta-analysis. RESULTS: The HEI-2015 was associated with 74 plasma and 73 gut metabolites (mostly lipids) and with 47 metabolites in the meta-analysis of the ABO and FAIR Studies. Compared to Enterotype-1 participants, those with Enterotype-2 had higher diet quality (p = 0.01). We also identified 9 microbial genera associated with HEI, and 35 plasma and 40 gut metabolites linked to the HEI-gut microbiome interaction. Pathways involved in the metabolism of polar lipids, amino acids and caffeine strongly associated with diet quality. However, the HEI-microbiome interaction not only influenced the pathways involved in the metabolism of branch-chain amino acids, it also affected upstream pathways including nucleotide metabolism and amino acids biosynthesis. CONCLUSIONS: Our multi-omic analysis demonstrated that changes in metabolism, measured by either circulatory/gut metabolites or metabolic pathways, are influenced by not only diet quality but also gut microbiome alterations shaped by the quality of diet consumed. Future work is needed to explore the causality in the interplay between HEI and gut-microbiome composition in metabolism.

New-onset vegetarian diet shows differences in fatty acid metabolites in European American and African American women.

BACKGROUND AND AIMS: The type of fat consumed in animal-based western diets, typically rich in the saturated fat palmitate, has been implicated in cardiometabolic disease risk. In contrast, the most abundant mono- and polyunsaturated fats, more typical in a vegetarian or plant-based diet, potentiate less deleterious effects. This study determined differences in plasma and urine metabolites when switching from omnivorous to vegetarian diet, including metabolites involved in fatty acid utilization. METHODS AND RESULTS: A prospective cohort of 38 European (EA) and African American (AA) omnivorous females were matched by age (25.7 ± 5.3y) and BMI (22.4 ± 1.9 kg/m2). Pre-intervention samples were collected while subjects consumed habitual animal-based diet. Changes in metabolites were assessed by ultra-high-performance liquid chromatography-tandem mass spectroscopy (Metabolon, Inc.) upon completing four days of novel vegetarian diet provided by the Vanderbilt Metabolic Kitchen. Changes in several diet-derived metabolites were observed, including increases in compounds derived from soy food metabolism along with decreases in metabolites of xanthine and histidine. Significant changes occurred in metabolites of saturated, monounsaturated and polyunsaturated fatty acids along with significant differences between EA and AA women in changes in plasma concentrations of acylcarnitines, which reflect the completeness of fatty acid oxidation (versus storage). CONCLUSION: These data suggest improvements in fatty acid metabolism (oxidation vs storage), a key factor in energy homeostasis, may be promoted rapidly by adoption of a vegetarian (plant-based) diet. Mechanistic differences in response to diet interventions must be understood to effectively provide protection against the widespread development of obesity and cardiometabolic disease in population subgroups, such as AA women.

Metabolomics reveals the impact of Type 2 diabetes on local muscle and vascular responses to ischemic stress.

OBJECTIVE: Type 2 diabetes mellitus (T2DM) reduces exercise capacity, but the mechanisms are incompletely understood. We probed the impact of ischemic stress on skeletal muscle metabolite signatures and T2DM-related vascular dysfunction. METHODS: we recruited 38 subjects (18 healthy, 20 T2DM), placed an antecubital intravenous catheter, and performed ipsilateral brachial artery reactivity testing. Blood samples for plasma metabolite profiling were obtained at baseline and immediately upon cuff release after 5 min of ischemia. Brachial artery diameter was measured at baseline and 1 min after cuff release. RESULTS: as expected, flow-mediated vasodilation was attenuated in subjects with T2DM (P<0.01). We confirmed known T2DM-associated baseline differences in plasma metabolites, including homocysteine, dimethylguanidino valeric acid and ß-alanine (all P<0.05). Ischemia-induced metabolite changes that differed between groups included 5-hydroxyindoleacetic acid (healthy: -27%; DM +14%), orotic acid (healthy: +5%; DM -7%), trimethylamine-N-oxide (healthy: -51%; DM +0.2%), and glyoxylic acid (healthy: +19%; DM -6%) (all P<0.05). Levels of serine, betaine, ß-aminoisobutyric acid and anthranilic acid were associated with vessel diameter at baseline, but only in T2DM (all P<0.05). Metabolite responses to ischemia were significantly associated with vasodilation extent, but primarily observed in T2DM, and included enrichment in phospholipid metabolism (P<0.05). CONCLUSIONS: our study highlights impairments in muscle and vascular signaling at rest and during ischemic stress in T2DM. While metabolites change in both healthy and T2DM subjects in response to ischemia, the relationship between muscle metabolism and vascular function is modified in T2DM, suggesting that dysregulated muscle metabolism in T2DM may have direct effects on vascular function.

The Gut Microbiome, Inflammation, and Salt-Sensitive Hypertension.

PURPOSE OF REVIEW: Salt sensitivity of blood pressure (SSBP) is an independent predictor of death due to cardiovascular events and affects nearly 50% of the hypertensive and 25% of the normotensive population. Strong evidence indicates that reducing sodium (Na+) intake decreases blood pressure (BP) and cardiovascular events. The precise mechanisms of how dietary Na+ contributes to elevation and cardiovascular disease remain unclear. The goal of this review is to discuss mechanisms of salt-induced cardiovascular disease and how the microbiome may play a role. RECENT FINDINGS: The innate and adaptive immune systems are involved in the genesis of salt-induced hypertension. Mice fed a high-salt diet exhibit increased inflammation with a marked increase in dendritic cell (DC) production of interleukin (IL)-6 and formation of isolevuglandins (IsoLG)-protein adducts, which drive interferon-gamma (IFN-γ) and IL-17A production by T cells. While prior studies have mainly focused on the brain, kidney, and vasculature as playing a role in salt-induced hypertension, the gut is the first and largest location for Na+ absorption. Research from our group and others strongly suggests that the gut microbiome contributes to salt-induced inflammation and hypertension. Recent studies suggest that alterations in the gut microbiome contribute to salt-induced hypertension. However, the contribution of the microbiome to SSBP and its underlying mechanisms are not known. Targeting the microbiota and the associated immune cell activation could conceivably provide the much-needed therapy for SSBP.

Soy food intake associates with changes in the metabolome and reduced blood pressure in a gut microbiota dependent manner.

BACKGROUND AND AIMS: Consumption of soy foods has been associated with protection against cardiometabolic disease, but the mechanisms are incompletely understood. We hypothesized that habitual soy food consumption associates with gut microbiome composition, metabolite production, and the interaction between diet, microbiota and metabolites. METHODS AND RESULTS: We analyzed dietary soy intake, plasma and stool metabolites, and gut microbiome data from two independent cross-sectional samples of healthy US individuals (N = 75 lean or overweight, and N = 29 obese). Habitual soy intake associated with several circulating metabolites. There was a significant interaction between soy intake and gut microbiome composition, as defined by gut enterotype, on metabolites in plasma and stool. Soy consumption associated with reduced systolic blood pressure, but only in a subset of individuals defined by their gut microbiome enterotype, suggesting that responsiveness to soy may be dependent on microbiome composition. Soy intake was associated with differences in specific microbial taxa, including two taxa mapping to genus Dialister and Prevotella which appeared to be suppressed by high soy intake We identified context-dependent effects of these taxa, where presence of Prevotella was associated with higher blood pressure and a worse cardiometabolic profile, but only in the absence of Dialister. CONCLUSIONS: The gut microbiome is an important intermediate in the interplay between dietary soy intake and systemic metabolism. Consumption of soy foods may shape the microbiome by suppressing specific taxa, and may protect against hypertension only in individuals with soy-responsive microbiota. CLINICAL TRIALS REGISTRY: NCT02010359 at clinicaltrials.gov.

Probing the Virtual Proteome to Identify Novel Disease Biomarkers.

BACKGROUND: Proteomic approaches allow measurement of thousands of proteins in a single specimen, which can accelerate biomarker discovery. However, applying these technologies to massive biobanks is not currently feasible because of the practical barriers and costs of implementing such assays at scale. To overcome these challenges, we used a "virtual proteomic" approach, linking genetically predicted protein levels to clinical diagnoses in >40 000 individuals. METHODS: We used genome-wide association data from the Framingham Heart Study (n=759) to construct genetic predictors for 1129 plasma protein levels. We validated the genetic predictors for 268 proteins and used them to compute predicted protein levels in 41 288 genotyped individuals in the Electronic Medical Records and Genomics (eMERGE) cohort. We tested associations for each predicted protein with 1128 clinical phenotypes. Lead associations were validated with directly measured protein levels and either low-density lipoprotein cholesterol or subclinical atherosclerosis in the MDCS (Malmö Diet and Cancer Study; n=651). RESULTS: In the virtual proteomic analysis in eMERGE, 55 proteins were associated with 89 distinct diagnoses at a false discovery rate q<0.1. Among these, 13 associations involved lipid (n=7) or atherosclerosis (n=6) phenotypes. We tested each association for validation in MDCS using directly measured protein levels. At Bonferroni-adjusted significance thresholds, levels of apolipoprotein E isoforms were associated with hyperlipidemia, and circulating C-type lectin domain family 1 member B and platelet-derived growth factor receptor-ß predicted subclinical atherosclerosis. Odds ratios for carotid atherosclerosis were 1.31 (95% CI, 1.08-1.58; P=0.006) per 1-SD increment in C-type lectin domain family 1 member B and 0.79 (0.66-0.94; P=0.008) per 1-SD increment in platelet-derived growth factor receptor-ß. CONCLUSIONS: We demonstrate a biomarker discovery paradigm to identify candidate biomarkers of cardiovascular and other diseases.

Loss of Cardioprotective Effects at the ADAMTS7 Locus as a Result of Gene-Smoking Interactions.

BACKGROUND: Common diseases such as coronary heart disease (CHD) are complex in etiology. The interaction of genetic susceptibility with lifestyle factors may play a prominent role. However, gene-lifestyle interactions for CHD have been difficult to identify. Here, we investigate interaction of smoking behavior, a potent lifestyle factor, with genotypes that have been shown to associate with CHD risk. METHODS: We analyzed data on 60 919 CHD cases and 80 243 controls from 29 studies for gene-smoking interactions for genetic variants at 45 loci previously reported to be associated with CHD risk. We also studied 5 loci associated with smoking behavior. Study-specific gene-smoking interaction effects were calculated and pooled using fixed-effects meta-analyses. Interaction analyses were declared to be significant at a P value of <1.0×10-3 (Bonferroni correction for 50 tests). RESULTS: We identified novel gene-smoking interaction for a variant upstream of the ADAMTS7 gene. Every T allele of rs7178051 was associated with lower CHD risk by 12% in never-smokers (P=1.3×10-16) in comparison with 5% in ever-smokers (P=2.5×10-4), translating to a 60% loss of CHD protection conferred by this allelic variation in people who smoked tobacco (interaction P value=8.7×10-5). The protective T allele at rs7178051 was also associated with reduced ADAMTS7 expression in human aortic endothelial cells and lymphoblastoid cell lines. Exposure of human coronary artery smooth muscle cells to cigarette smoke extract led to induction of ADAMTS7. CONCLUSIONS: Allelic variation at rs7178051 that associates with reduced ADAMTS7 expression confers stronger CHD protection in never-smokers than in ever-smokers. Increased vascular ADAMTS7 expression may contribute to the loss of CHD protection in smokers.

Relationship between very low low-density lipoprotein cholesterol concentrations not due to statin therapy and risk of type 2 diabetes: A US-based cross-sectional observational study using electronic health records.

BACKGROUND: Observations from statin clinical trials and from Mendelian randomization studies suggest that low low-density lipoprotein cholesterol (LDL-C) concentrations may be associated with increased risk of type 2 diabetes mellitus (T2DM). Despite the findings from statin clinical trials and genetic studies, there is little direct evidence implicating low LDL-C concentrations in increased risk of T2DM. METHODS AND FINDINGS: We used de-identified electronic health records (EHRs) at Vanderbilt University Medical Center to compare the risk of T2DM in a cross-sectional study among individuals with very low (≤60 mg/dl, N = 8,943) and normal (90-130 mg/dl, N = 71,343) LDL-C levels calculated using the Friedewald formula. LDL-C levels associated with statin use, hospitalization, or a serum albumin level < 3 g/dl were excluded. We used a 2-phase approach: in 1/3 of the sample (discovery) we used T2DM phenome-wide association study codes (phecodes) to identify cases and controls, and in the remaining 2/3 (validation) we identified T2DM cases and controls using a validated algorithm. The analysis plan for the validation phase was constructed at the time of the design of that component of the study. The prevalence of T2DM in the very low and normal LDL-C groups was compared using logistic regression with adjustment for age, race, sex, body mass index (BMI), high-density lipoprotein cholesterol, triglycerides, and duration of care. Secondary analyses included prespecified stratification by sex, race, BMI, and LDL-C level. In the discovery cohort, phecodes related to T2DM were significantly more frequent in the very low LDL-C group. In the validation cohort (N = 33,039 after applying the T2DM algorithm to identify cases and controls), the risk of T2DM was increased in the very low compared to normal LDL-C group (odds ratio [OR] 2.06, 95% CI 1.80-2.37; P < 2 × 10-16). The findings remained significant in sensitivity analyses. The association between low LDL-C levels and T2DM was significant in males (OR 2.43, 95% CI 2.00-2.95; P < 2 × 10-16) and females (OR 1.74, 95% CI 1.42-2.12; P = 6.88 × 10-8); in normal weight (OR 2.18, 95% CI 1.59-2.98; P = 1.1× 10-6), overweight (OR 2.17, 95% CI 1.65-2.83; P = 1.73× 10-8), and obese (OR 2.00, 95% CI 1.65-2.41; P = 8 × 10-13) categories; and in individuals with LDL-C < 40 mg/dl (OR 2.31, 95% CI 1.71-3.10; P = 3.01× 10-8) and LDL-C 40-60 mg/dl (OR 1.99, 95% CI 1.71-2.32; P < 2.0× 10-16). The association was significant in individuals of European ancestry (OR 2.67, 95% CI 2.25-3.17; P < 2 × 10-16) but not in those of African ancestry (OR 1.09, 95% CI 0.81-1.46; P = 0.56). A limitation was that we only compared groups with very low and normal LDL-C levels; also, since this was not an inception cohort, we cannot exclude the possibility of reverse causation. CONCLUSIONS: Very low LDL-C concentrations occurring in the absence of statin treatment were significantly associated with T2DM risk in a large EHR population; this increased risk was present in both sexes and all BMI categories, and in individuals of European ancestry but not of African ancestry. Longitudinal cohort studies to assess the relationship between very low LDL-C levels not associated with lipid-lowering therapy and risk of developing T2DM will be important.

De novo RNA sequence assembly during in vivo inflammatory stress reveals hundreds of unannotated lincRNAs in human blood CD14+ monocytes and in adipose tissue.

Long intergenic noncoding RNAs (lincRNAs) have emerged as key regulators of cellular functions and physiology. Yet functional lincRNAs often have low, context-specific and tissue-specific expression. We hypothesized that many human monocyte and adipose lincRNAs would be absent in current public annotations due to lincRNA tissue specificity, modest sequencing depth in public data, limitations of transcriptome assembly algorithms, and lack of dynamic physiological contexts. Deep RNA sequencing (RNA-Seq) was performed in peripheral blood CD14+ monocytes (monocytes; average ~247 million reads per sample) and adipose tissue (average ~378 million reads per sample) collected before and after human experimental endotoxemia, an in vivo inflammatory stress, to identify tissue-specific and clinically relevant lincRNAs. Using a stringent filtering pipeline, we identified 109 unannotated lincRNAs in monocytes and 270 unannotated lincRNAs in adipose. Most unannotated lincRNAs are not conserved in rodents and are tissue specific, while many have features of regulated expression and are enriched in transposable elements. Specific subsets have enhancer RNA characteristics or are expressed only during inflammatory stress. A subset of unannotated lincRNAs was validated and replicated for their presence and inflammatory induction in independent human samples and for their monocyte and adipocyte origins. Through interrogation of public genome-wide association data, we also found evidence of specific disease association for selective unannotated lincRNAs. Our findings highlight the critical need to perform deep RNA-Seq in a cell-, tissue-, and context-specific manner to annotate the full repertoire of human lincRNAs for a complete understanding of lincRNA roles in dynamic cell functions and in human disease.

Sedentary Behavior and Cardiovascular Morbidity and Mortality: A Science Advisory From the American Heart Association.

Epidemiological evidence is accumulating that indicates greater time spent in sedentary behavior is associated with all-cause and cardiovascular morbidity and mortality in adults such that some countries have disseminated broad guidelines that recommend minimizing sedentary behaviors. Research examining the possible deleterious consequences of excess sedentary behavior is rapidly evolving, with the epidemiology-based literature ahead of potential biological mechanisms that might explain the observed associations. This American Heart Association science advisory reviews the current evidence on sedentary behavior in terms of assessment methods, population prevalence, determinants, associations with cardiovascular disease incidence and mortality, potential underlying mechanisms, and interventions. Recommendations for future research on this emerging cardiovascular health topic are included. Further evidence is required to better inform public health interventions and future quantitative guidelines on sedentary behavior and cardiovascular health outcomes.

Integrative genomics identifies 7p11.2 as a novel locus for fever and clinical stress response in humans.

Fever predicts clinical outcomes in sepsis, trauma and during cardiovascular stress, yet the genetic determinants are poorly understood. We used an integrative genomics approach to identify novel genomic determinants of the febrile response to experimental endotoxemia. We highlight multiple integrated lines of evidence establishing the clinical relevance of this novel fever locus. Through genome-wide association study (GWAS) of evoked endotoxemia (lipopolysaccharide (LPS) 1 ng/kg IV) in healthy subjects of European ancestry we discovered a locus on chr7p11.2 significantly associated with the peak febrile response to LPS (top single nucleotide polymorphism (SNP) rs7805622, P = 2.4 × 10(-12)), as well as with temperature fluctuation over time. We replicated this association in a smaller independent LPS study (rs7805622, P = 0.03). In clinical translation, this locus was also associated with temperature and mortality in critically ill patients with trauma or severe sepsis. The top GWAS SNPs are not located within protein-coding genes, but have significant cis-expression quantitative trait loci (eQTL) associations with expression of a cluster of genes ∼400 kb upstream, several of which (SUMF2, CCT6A, GBAS) are regulated by LPS in vivo in blood cells. LPS- and cold-treatment of adipose stromal cells in vitro suggest genotype-specific modulation of eQTL candidate genes (PSPH). Several eQTL genes were up-regulated in brown and white adipose following cold exposure in mice, highlighting a potential role in thermogenesis. Thus, through genomic interrogation of experimental endotoxemia, we identified and replicated a novel fever locus on chr7p11.2 that modulates clinical responses in trauma and sepsis, and highlight integrated in vivo and in vitro evidence for possible novel cis candidate genes conserved across human and mouse.