Biomarkers of Dietary Omega-6 Fatty Acids and Incident Cardiovascular Disease and Mortality.

BACKGROUND: Global dietary recommendations for and cardiovascular effects of linoleic acid, the major dietary omega-6 fatty acid, and its major metabolite, arachidonic acid, remain controversial. To address this uncertainty and inform international recommendations, we evaluated how in vivo circulating and tissue levels of linoleic acid (LA) and arachidonic acid (AA) relate to incident cardiovascular disease (CVD) across multiple international studies. METHODS: We performed harmonized, de novo, individual-level analyses in a global consortium of 30 prospective observational studies from 13 countries. Multivariable-adjusted associations of circulating and adipose tissue LA and AA biomarkers with incident total CVD and subtypes (coronary heart disease, ischemic stroke, cardiovascular mortality) were investigated according to a prespecified analytic plan. Levels of LA and AA, measured as the percentage of total fatty acids, were evaluated linearly according to their interquintile range (ie, the range between the midpoint of the first and fifth quintiles), and categorically by quintiles. Study-specific results were pooled using inverse-variance-weighted meta-analysis. Heterogeneity was explored by age, sex, race, diabetes mellitus, statin use, aspirin use, omega-3 levels, and fatty acid desaturase 1 genotype (when available). RESULTS: In 30 prospective studies with medians of follow-up ranging 2.5 to 31.9 years, 15 198 incident cardiovascular events occurred among 68 659 participants. Higher levels of LA were significantly associated with lower risks of total CVD, cardiovascular mortality, and ischemic stroke, with hazard ratios per interquintile range of 0.93 (95% CI, 0.88-0.99), 0.78 (0.70-0.85), and 0.88 (0.79-0.98), respectively, and nonsignificantly with lower coronary heart disease risk (0.94; 0.88-1.00). Relationships were similar for LA evaluated across quintiles. AA levels were not associated with higher risk of cardiovascular outcomes; in a comparison of extreme quintiles, higher levels were associated with lower risk of total CVD (0.92; 0.86-0.99). No consistent heterogeneity by population subgroups was identified in the observed relationships. CONCLUSIONS: In pooled global analyses, higher in vivo circulating and tissue levels of LA and possibly AA were associated with lower risk of major cardiovascular events. These results support a favorable role for LA in CVD prevention.

Is high vitamin B12 status a cause of lung cancer?

Vitamin B supplementation can have side effects for human health, including cancer risk. We aimed to elucidate the role of vitamin B12 in lung cancer etiology via direct measurements of pre-diagnostic circulating vitamin B12 concentrations in a nested case-control study, complemented with a Mendelian randomization (MR) approach in an independent case-control sample. We used pre-diagnostic biomarker data from 5183 case-control pairs nested within 20 prospective cohorts, and genetic data from 29,266 cases and 56,450 controls. Exposures included directly measured circulating vitamin B12 in pre-diagnostic blood samples from the nested case-control study, and 8 single nucleotide polymorphisms associated with vitamin B12 concentrations in the MR study. Our main outcome of interest was increased risk for lung cancer, overall and by histological subtype, per increase in circulating vitamin B12 concentrations. We found circulating vitamin B12 to be positively associated with overall lung cancer risk in a dose response fashion (odds ratio for a doubling in B12 [ORlog2B12 ] = 1.15, 95% confidence interval (95%CI) = 1.06-1.25). The MR analysis based on 8 genetic variants also indicated that genetically determined higher vitamin B12 concentrations were positively associated with overall lung cancer risk (OR per 150 pmol/L standard deviation increase in B12 [ORSD ] = 1.08, 95%CI = 1.00-1.16). Considering the consistency of these two independent and complementary analyses, these findings support the hypothesis that high vitamin B12 status increases the risk of lung cancer.

Development and validation of a heart failure with preserved ejection fraction cohort using electronic medical records.

BACKGROUND: Heart failure (HF) with preserved ejection fraction (HFpEF) comprises nearly half of prevalent HF, yet is challenging to curate in a large database of electronic medical records (EMR) since it requires both accurate HF diagnosis and left ventricular ejection fraction (EF) values to be consistently ≥50%. METHODS: We used the national Veterans Affairs EMR to curate a cohort of HFpEF patients from 2002 to 2014. EF values were extracted from clinical documents utilizing natural language processing and an iterative approach was used to refine the algorithm for verification of clinical HFpEF. The final algorithm utilized the following inclusion criteria: any International Classification of Diseases-9 (ICD-9) code of HF (428.xx); all recorded EF ≥50%; and either B-type natriuretic peptide (BNP) or aminoterminal pro-BNP (NT-proBNP) values recorded OR diuretic use within one month of diagnosis of HF. Validation of the algorithm was performed by 3 independent reviewers doing manual chart review of 100 HFpEF cases and 100 controls. RESULTS: We established a HFpEF cohort of 80,248 patients (out of a total 1,155,376 patients with the ICD-9 diagnosis of HF). Mean age was 72 years; 96% were males and 12% were African-Americans. Validation analysis of the HFpEF algorithm had a sensitivity of 88%, specificity of 96%, positive predictive value of 96%, and a negative predictive value of 87% to identify HFpEF cases. CONCLUSION: We developed a sensitive, highly specific algorithm for detecting HFpEF in a large national database. This approach may be applicable to other large EMR databases to identify HFpEF patients.

Long-term outcomes in patients with acute coronary syndromes related to prolonging dual antiplatelet therapy more than 12 months after coronary stenting.

OBJECTIVES: To assess the impact of stent type on the risk of death or myocardial infarction (MI) related to dual antiplatelet therapy (DAPT) more than 12 months (prolonged DAPT) versus 12 or less months after PCI for an acute coronary syndrome (ACS). BACKGROUND: The recent DAPT study reported lower recurrent ischemic events from prolonged DAPT in patients treated with PCI for an ACS, but was underpowered to determine the impact of stent type. METHODS: We determined clinical outcomes after PCI for an ACS (median follow-up: DES = 26 months, BMS = 46 months) in 18,484 patients in the Veterans Affairs system treated with first generation drug-eluting stents (DES) or bare-metal stents (BMS). We used landmark analyses starting 1 year after the index PCI to assess the risk of prolonged DAPT on the primary endpoint of death or MI. Multivariable and propensity models adjusted for confounding. RESULTS: There was a significant interaction between stent type and prolonged DAPT for death and MI (P = 0.0036), death (P = 0.054), and major bleeding (P = 0.0013). Patients treated with prolonged DAPT had lower risks of death or MI (HR = 0.71, 95% CI = 0.61, 0.82) and death (HR = 0.74, 95%CI = 0.62, 0.89) with DES, but not BMS, and higher risks of major bleeding, particularly with BMS (HR = 1.67, P < 0.001) than DES (HR = 1.24, p = 0.01). CONCLUSIONS: Prolonging DAPT more than 12 months after PCI for ACS only associated with a lower risk of ischemic events in the 1-4 years after PCI in those receiving first generation DES. Stent type may influence the benefit of prolonged DAPT. © 2016 Wiley Periodicals, Inc.

Effect of continuous positive airway pressure treatment on pulmonary artery pressure in patients with isolated obstructive sleep apnea: a meta-analysis.

Pulmonary hypertension (PH) can occur in patients with obstructive sleep apnea (OSA) in the absence of cardiac or lung disease. Data on the development and severity of PH, and the effect of continuous positive airway pressure (CPAP) therapy on pulmonary artery (PA) pressures in these patients have been inconsistent in the literature. We sought to determine whether CPAP therapy affects PA pressures in patients with isolated OSA in this meta-analysis. We searched PubMed, Medline, EMBASE and other databases from January 1980 to August 2015. Studies of patients with OSA, defined as an apnea-hypopnea index >10 events/h, and PH, defined as PA pressure >25 mmHg were included. Two reviewers independently extracted data and assessed risk of bias. A total of 222 patients from seven studies (341.53 person-years) had reported PA pressures before and after treatment with CPAP therapy. 77 % of participants were men, with a mean age of 52.5 years, a mean apnea-hypopnea index of 58 events/h, and mean PA pressure of 39.3 ± 6.3 mmHg. CPAP treatment duration ranged from 3 to 70 months. Using fixed effects meta-analysis, CPAP therapy was associated with a decrease in PA pressure of 13.3 mmHg (95 % CI 12.7-14.0) in our study population. This meta-analysis found that CPAP therapy is associated with a significantly lower PA pressure in patients with isolated OSA and PH.

Biological Insights from Schizophrenia-associated Loci in Ancestral Populations.

Large-scale genome-wide association studies of schizophrenia have uncovered hundreds of associated loci but with extremely limited representation of African diaspora populations. We surveyed electronic health records of 200,000 individuals of African ancestry in the Million Veteran and All of Us Research Programs, and, coupled with genotype-level data from four case-control studies, realized a combined sample size of 13,012 affected and 54,266 unaffected persons. Three genome-wide significant signals - near PLXNA4, PMAIP1, and TRPA1 - are the first to be independently identified in populations of predominantly African ancestry. Joint analyses of African, European, and East Asian ancestries across 86,981 cases and 303,771 controls, yielded 376 distinct autosomal loci, which were refined to 708 putatively causal variants via multi-ancestry fine-mapping. Utilizing single-cell functional genomic data from human brain tissue and two complementary approaches, transcriptome-wide association studies and enhancer-promoter contact mapping, we identified a consensus set of 94 genes across ancestries and pinpointed the specific cell types in which they act. We identified reproducible associations of schizophrenia polygenic risk scores with schizophrenia diagnoses and a range of other mental and physical health problems. Our study addresses a longstanding gap in the generalizability of research findings for schizophrenia across ancestral populations, underlining shared biological underpinnings of schizophrenia across global populations in the presence of broadly divergent risk allele frequencies.

X-chromosome and kidney function: evidence from a multi-trait genetic analysis of 908,697 individuals reveals sex-specific and sex-differential findings in genes regulated by androgen response elements.

X-chromosomal genetic variants are understudied but can yield valuable insights into sexually dimorphic human traits and diseases. We performed a sex-stratified cross-ancestry X-chromosome-wide association meta-analysis of seven kidney-related traits (n = 908,697), identifying 23 loci genome-wide significantly associated with two of the traits: 7 for uric acid and 16 for estimated glomerular filtration rate (eGFR), including four novel eGFR loci containing the functionally plausible prioritized genes ACSL4, CLDN2, TSPAN6 and the female-specific DRP2. Further, we identified five novel sex-interactions, comprising male-specific effects at FAM9B and AR/EDA2R, and three sex-differential findings with larger genetic effect sizes in males at DCAF12L1 and MST4 and larger effect sizes in females at HPRT1. All prioritized genes in loci showing significant sex-interactions were located next to androgen response elements (ARE). Five ARE genes showed sex-differential expressions. This study contributes new insights into sex-dimorphisms of kidney traits along with new prioritized gene targets for further molecular research.

Erythrocyte stearidonic acid and other n-3 fatty acids and CHD in the Physicians' Health Study.

Intake of marine-based n-3 fatty acids (EPA, docosapentaenoic acid and DHA) is recommended to prevent CHD. Stearidonic acid (SDA), a plant-based n-3 fatty acid, is a precursor of EPA and may be more readily converted to EPA than a-linolenic acid (ALA). While transgenic soyabeans might supply SDA at low cost, it is unclear whether SDA is associated with CHD risk. Furthermore, associations of other n-3 fatty acids with CHD risk remain inconsistent. The present ancillary study examined the association of erythrocyte SDA as well as other n-3 fatty acids with the risk of CHD. In a prospective nested case-control study of the Physicians' Health Study, we randomly selected 1000 pairs of incident CHD with matching controls. Erythrocyte fatty acids were measured using GC. We used conditional logistic regression to estimate relative risks. Mean age was 68·7 (SD 8·7) years. In a multivariable model controlling for matching factors and established CHD risk factors, OR for CHD for each standard deviation increase of log-SDA was 1·03 (95% CI 0·90, 1·18). Corresponding values for log-ALA and log-marine n-3 fatty acids were 1·04 (95% CI 0·94, 1·16) and 0·97 (95% CI 0·88, 1·07), respectively. In conclusion, the present data did not show an association among erythrocyte SDA, ALA or marine n-3 fatty acids and the risk of CHD in male physicians.

Y chromosome haplogroups and prostate cancer in populations of European and Ashkenazi Jewish ancestry.

Genetic variation on the Y chromosome has not been convincingly implicated in prostate cancer risk. To comprehensively analyze the role of inherited Y chromosome variation in prostate cancer risk in individuals of European ancestry, we genotyped 34 binary Y chromosome markers in 3,995 prostate cancer cases and 3,815 control subjects drawn from four studies. In this set, we identified nominally significant association between a rare haplogroup, E1b1b1c, and prostate cancer in stage I (P = 0.012, OR = 0.51; 95% confidence interval 0.30-0.87). Population substructure of E1b1b1c carriers suggested Ashkenazi Jewish ancestry, prompting a replication phase in individuals of both European and Ashkenazi Jewish ancestry. The association was not significant for prostate cancer overall in studies of either Ashkenazi Jewish (1,686 cases and 1,597 control subjects) or European (686 cases and 734 control subjects) ancestry (P(meta) = 0.078), but a meta-analysis of stage I and II studies revealed a nominally significant association with prostate cancer risk (P(meta) = 0.010, OR = 0.77; 95% confidence interval 0.62-0.94). Comparing haplogroup frequencies between studies, we noted strong similarities between those conducted in the US and France, in which the majority of men carried R1 haplogroups, resembling Northwestern European populations. On the other hand, Finns had a remarkably different haplogroup distribution with a preponderance of N1c and I1 haplogroups. In summary, our results suggest that inherited Y chromosome variation plays a limited role in prostate cancer etiology in European populations but warrant follow-up in additional large and well characterized studies of multiple ethnic backgrounds.

The association between height and prostate cancer grade in the Early Stage Prostate Cancer Cohort Study.

OBJECTIVE: We examined the relationship between height and prostate cancer grade. METHODS: The Early Stage Prostate Cancer Cohort Study is an observational cohort of 1,037 men diagnosed with early-stage prostate cancer, T(0-3)N(x)M(0). High-grade prostate cancer was defined as a biopsy Gleason score ≥ 7 (4 + 3). Logistic regression models were created to calculate odds ratios (OR) and 95% confidence intervals (CI) for the cross-sectional relationship between height and prostate cancer grade in the overall cohort and subpopulations. RESULTS: We identified 939 participants with a biopsy Gleason score. High-grade prostate cancer was diagnosed in 138 participants. Overall, participants in the highest quartile of height were more than twice as likely to have a Gleason score ≥ 7 (4 + 3) than participants in the lowest quartile of height, OR 2.14 (95% CI 1.11, 4.14), after multivariate adjustment. Participants in the highest quartile of height were more likely to be diagnosed with high-grade prostate cancer than participants in the lowest quartile of height among participants who were black, OR 8.00 (95% CI 1.99, 32.18), and participants who had diabetes mellitus, OR 5.09 (95% CI 1.30, 19.98). CONCLUSIONS: Height is associated with increased risk of high-grade prostate cancer overall and perhaps among certain subpopulations.

Alcohol intake and pancreatic cancer: a pooled analysis from the pancreatic cancer cohort consortium (PanScan).

The literature has consistently reported no association between low to moderate alcohol consumption and pancreatic cancer; however, a few studies have shown that high levels of intake may increase risk. Most single studies have limited power to detect associations even in the highest alcohol intake categories or to examine associations by alcohol type. We analyzed these associations using 1,530 pancreatic cancer cases and 1,530 controls from the Pancreatic Cancer Cohort Consortium (PanScan) nested case-control study. Odds ratios (OR) and 95% confidence intervals (95% CI) were calculated using unconditional logistic regression, adjusting for potential confounders. We observed no significant overall association between total alcohol (ethanol) intake and pancreatic cancer risk (OR = 1.38, 95% CI = 0.86-2.23, for 60 or more g/day vs. >0 to <5 g/day). A statistically significant increase in risk was observed among men consuming 45 or more grams of alcohol from liquor per day (OR = 2.23, 95% CI = 1.02-4.87, compared to 0 g/day of alcohol from liquor, P-trend = 0.12), but not among women (OR = 1.35, 95% CI = 0.63-2.87, for 30 or more g/day of alcohol from liquor, compared to none). No associations were noted for wine or beer intake. Overall, no significant increase in risk was observed, but a small effect among heavy drinkers cannot be ruled out.

Alcohol consumption and risk of heart failure: a meta-analysis.

BACKGROUND: Heart failure is highly prevalent among older adults and is associated with high treatment costs. Identifying modifiable determinants of heart failure may help in prevention. Alcohol consumption has emerged as a modifiable risk factor for cardiovascular diseases. Although many studies have suggested a positive association between heavy drinking and cardiomyopathy, the association between infrequent or light-to-moderate drinking and heart failure risk has been less conclusive. PURPOSE: To examine the relation between various levels of alcohol intake and incident heart failure. METHODS: We conducted a meta-analysis of 6 studies obtained through a PubMed literature search. Alcohol drinkers were classified as never, former, and current drinkers of 0.1 to 0.9, 1 to 7, 8 to 14, and > 14 drinks per week. RESULTS: Compared with never drinkers, the pooled relative risks were 1.16 (95% confidence interval [CI], 0.90-1.51) for former drinkers, 0.90 (95% CI, 0.83-0.98), 0.80 (95% CI, 0.73-0.88), 0.78 (95% CI, 0.65-0.95), and 0.77 (95% CI, 0.63-0.95) for current drinkers of 0.1 to 0.9, 1 to 7, 8 to 14, and > 14 drinks per week, respectively, in a random effects model. CONCLUSION: These data suggest that infrequent and light-to-moderate drinking is associated with a lower risk of heart failure.

Low-density lipoprotein reduction and magnitude of cardiovascular risk reduction.

The authors examined the relationship between the magnitude of low-density lipoprotein cholesterol (LDL-C) reduction and the magnitude of cardiovascular risk reduction. From the Veterans Integrated Service Network 1 databases, the authors selected 54,611 patients with prevalent ischemic heart disease, peripheral vascular disease or diabetes mellitus, and >or=2 documented LDL-C levels who were followed between 1997 and 2006. The outcome was defined as acute myocardial infarction or revascularization. Preoutcome LDL-C reduction was categorized as follows: <10 mg/dL, reference; >or=10 but <40 mg/dL, small reduction; >or=40 but <70 mg/dL, moderate reduction; >or=70 mg/dL, large reduction. Proportional hazards were used to determine the hazard ratio for the outcome for each LDL-C reduction category compared with the reference. Results revealed a graded relationship between the magnitude of reduction in LDL-C and cardiovascular risk reduction. Stratified analyses demonstrated these findings to be robust regardless of initial LDL-C levels or whether patients achieved "target" final LDL-C values of <100 mg/dL.

The relationship between total plasma carotenoids and risk factors for chronic disease among middle-aged and older men.

Individual plasma carotenoids have been associated with various chronic diseases but little is known about the relationship between total plasma carotenoids and risk factors for chronic diseases. In the Physicians' Health Study, we examined 492 men free of CVD and cancer for the relationship between total plasma carotenoids (the sum of alpha-carotene, beta-carotene, lycopene, zeaxanthin, lutein and beta-cryptoxanthin) and a wide variety of factors that predict chronic disease. Multivariate linear and logistic regression was performed to calculate parameter estimates (95% CI) and OR (95% CI) for total plasma carotenoids. In linear regression models, BMI, hypertension, alcohol intake and plasma levels of each lipid parameter and a-tocopherol significantly predicted levels of total plasma carotenoids. Upon adjustment for multiple chronic disease risk factors, the OR for levels of total plasma carotenoids greater than or equal to the median (> or=1.301 micromol/l) was statistically significant for current smoking (OR 0.21; 95% CI 0.06, 0.77), weekly alcohol ingestion (OR 2.30; 95% CI 1.06, 4.99), daily alcohol ingestion (OR 2.46; 95% CI 1.29, 4.67), each 100 mg/l increase in total cholesterol (OR 0.73; 95% CI 0.58, 0.91), LDL-cholesterol (OR 1.48; 95% CI 1.17, 1.89) and HDL-cholesterol (OR 1.58; 95% CI 1.26, 1.99), each 100 mg/ml increase in intercellular adhesion molecule-1 (OR 0.70; 95% CI 0.53, 0.93) and each 10 micromol/l increase in alpha-tocopherol (OR 1.33; 95% CI 1.12, 1.57), using logistic regression. Few lifestyle and clinical risk factors appear to be related to levels of total plasma carotenoids; however, levels of biomarkers such as plasma lipids and alpha-tocopherol may be strongly related.

High-density lipoprotein and mortality before age 90 in male physicians.

BACKGROUND: In cross-sectional and some cohort studies with shorter follow-up, high-density lipoprotein cholesterol (HDL-C) has been associated with longer life. We sought to examine the relationship between HDL-C and death before age 90 in the Physicians' Health Study (PHS). METHODS AND RESULTS: Of PHS enrollees who had blood collected at PHS II baseline (approximately 1997), we selected 1351 men old enough to reach age 90 by March 4, 2009, and with complete data on HDL-C and total cholesterol, lifestyle factors, and comorbidities. We used Cox proportional hazards to determine the hazard ratios (HRs) and 95% confidence intervals (CIs) for all-cause, cardiovascular disease (CVD), and non-CVD mortality before age 90, adjusting for potential confounders. After a mean (SD) follow-up of 6.8 (3.2) years, 44.1% of men in the lowest baseline HDL-C quartile (<32.8 mg/dL) compared with 32.9% (11.2% absolute risk reduction) in the highest HDL-C quartile (≥ 54.1 mg/dL) died before age 90. In multivariable adjusted analyses, men in the highest HDL-C quartile had a 28% lower risk (HR, 0.72; 95% CI, 0.55 to 0.94) of death before age 90 compared with men in the lowest HDL-C quartile. In age-adjusted analyses, increasing baseline HDL-C was significantly associated with a lower risk of CVD death. No association was found between HDL-C and non-CVD mortality. CONCLUSION: In male physicians, higher baseline HDL-C levels were associated with a lower risk of all-cause and CVD mortality before age 90.

Underuse of diagnostic codes for specific dementias in the Veterans Affairs New England healthcare system.

OBJECTIVES: To examine the specificity of dementia coding in large populations. DESIGN: Retrospective cohort and chart review study of dementia diagnosis. SETTING: U.S. Department of Veterans Affairs (VA) New England healthcare system. PARTICIPANTS: Veterans aged 50 and older given outpatient visit codes for dementia between January 1, 2000, and December 31, 2009. MEASUREMENTS: The frequency of the code "dementia not otherwise specified (DNOS)" as a first and final diagnosis was determined. DNOS use was examined according to provider type and geographic location. The medical records of 100 individuals with unspecified dementia were reviewed to determine their underlying diagnoses and describe their examination. RESULTS: Twenty-two thousand fifty veterans diagnosed with dementia were identified over 10 years of follow-up. One-third of all cases had no specific dementia code (n = 6,659). DNOS was the most commonly used code as a first dementia diagnosis (42.5%) and was second only to Alzheimer's type dementia (35.8%) as a final diagnosis. Individuals who saw geriatricians and neurologists were most likely to have a specific dementia diagnosis, and DNOS use was lowest in centers with the most dementia specialists. Only 12% of primary care physicians performed cognitive testing the first time they used the DNOS code, compared with 98% of specialists. Nearly half of individuals with a persistent diagnosis of DNOS met criteria for a specific dementia. CONCLUSION: Substantial overuse was found of nonspecific dementia codes in the VA New England healthcare system, leading to an underestimation of the prevalence of Alzheimer's disease and other dementias. System-based changes in dementia coding and greater access to dementia specialists may help improve diagnostic specificity.