Plasma Biomarker Profiles for Premature and Nonpremature Coronary Heart Disease in Women

BACKGROUND

Premature coronary heart disease (CHD) is a major cause of death in women. We aimed to characterize biomarker profiles of women who developed CHD before and after age 65 years.

METHODS

In the Women's Health Study (median follow-up 21.5 years), women were grouped by age and timing of incident CHD: baseline age <65 years with premature CHD by age 65 years (25 042 women; 447 events) and baseline age ≥65 years with nonpremature CHD (2982 women; 351 events). Associations of 44 baseline plasma biomarkers measured using standard assays and a nuclear magnetic resonance (NMR)-metabolomics assay were analyzed using Cox models adjusted for clinical risk factors.

RESULTS

Twelve biomarkers showed associations only with premature CHD and included lipoprotein(a), which was associated with premature CHD [adjusted hazard ratio (HR) per SD: 1.29 (95% CI 1.17-1.42)] but not with nonpremature CHD [1.09(0.98-1.22)](Pinteraction = 0.02). NMR-measured lipoprotein insulin resistance was associated with the highest risk of premature CHD [1.92 (1.52-2.42)] but was not associated with nonpremature CHD (Pinteraction <0.001). Eleven biomarkers showed stronger associations with premature vs nonpremature CHD, including apolipoprotein B. Nine NMR biomarkers showed no association with premature or nonpremature CHD, whereas 12 biomarkers showed similar significant associations with premature and nonpremature CHD, respectively, including low-density lipoprotein (LDL) cholesterol [1.30(1.20-1.45) and 1.22(1.10-1.35)] and C-reactive protein [1.34(1.19-1.50) and 1.25(1.08-1.44)].

CONCLUSIONS

In women, a profile of 12 biomarkers was selectively associated with premature CHD, driven by lipoprotein(a) and insulin-resistant atherogenic dyslipoproteinemia. This has implications for the development of biomarker panels to screen for premature CHD.

Effect of multivitamin-mineral supplementation versus placebo on cognitive function: results from the clinic subcohort of the COcoa Supplement and Multivitamin Outcomes Study (COSMOS) randomized clinical trial and meta-analysis of 3 cognitive studies within COSMOS

BACKGROUND

Longer effects of multivitamin-mineral (MVM) supplementation on late-life cognitive function remain untested using in-person, detailed neuropsychological assessments. Furthermore, insufficient evidence exists for healthcare providers to recommend daily MVM supplements to prevent cognitive decline.

OBJECTIVES

This study aimed to test MVM effects on cognitive change using in-person, detailed neuropsychological assessments and conduct a meta-analysis within COSMOS (COcoa Supplement and Multivitamin Outcomes Study) cognitive substudies for a robust evaluation of MVM effects on cognition.

METHODS

COSMOS is a 2 × 2 factorial trial of cocoa extract (500 mg flavanols/d) and/or a daily MVM supplement for cardiovascular disease and cancer prevention among 21,442 United States adults aged ≥60 y. There were 573 participants in the clinic subcohort of COSMOS (that is, COSMOS-Clinic) who completed all cognitive tests administered at baseline. For the meta-analysis, we included nonoverlapping participants across 3 COSMOS cognitive substudies: COSMOS-Clinic (n = 573); COSMOS-Mind (n = 2158); COSMOS-Web (n = 2472).

RESULTS

In COSMOS-Clinic, we observed a modest benefit of MVM compared with placebo on global cognition over 2 y {mean difference [95% confidence interval (CI)] = 0.06 SD units (SU) (-0.003, 0.13)}, with a significantly more favorable change in episodic memory [mean difference (95% CI) = 0.12 SU (0.002, 0.23)] but not in executive function or attention [mean difference (95% CI) = 0.04 SU (-0.04, 0.11)]. The meta-analysis of COSMOS substudies showed clear evidence of MVM benefits on global cognition [mean difference (95% CI) = 0.07 SU (0.03, 0.11); P = 0.0009] and episodic memory [mean difference (95% CI) = 0.06 SU (0.03, 0.10); P = 0.0007]; the magnitude of effect on global cognition was equivalent to reducing cognitive aging by 2 y.

CONCLUSIONS

In COSMOS-Clinic, daily MVM supplementation leads to a significantly more favorable 2-y change in episodic memory. The meta-analysis within COSMOS cognitive substudies indicates that daily MVM significantly benefits both global cognition and episodic memory. These findings within the COSMOS trial support the benefits of a daily MVM in preventing cognitive decline among older adults. This trial was registered at COSMOS-clinicaltrials.gov as NCT02422745, at COSMOS-Mind-clinicaltrials.gov as NCT03035201, and at COSMOS-Web-clinicaltrials.gov as NCT04582617.

Effect of cocoa extract supplementation on cognitive function: results from the clinic subcohort of the COSMOS trial

BACKGROUND

Some prior randomized clinical trials (RCTs) that tested the effects of cocoa extract (CE), a source of flavanols, on late-life cognition have yielded promising findings. A long-term RCT using in-person neuropsychological tests covering multiple cognitive domains may clarify the cognitive effects of CE.

OBJECTIVES

To test whether daily supplementation with CE, compared with placebo, produces better cognitive change over 2 y.

METHODS

The COcoa Supplement and Multivitamin Outcomes Study (COSMOS) is a 2 × 2 factorial RCT of CE [500 mg flavanols/d, including 80 mg (-)-epicatechin] and/or a daily multivitamin-mineral supplement for cardiovascular disease and cancer prevention among 21,442 United States adults aged ≥60 y. There were 573 participants in the clinic subcohort of COSMOS (that is, COSMOS-Clinic) who completed all cognitive tests at baseline; of these, 492 completed 2-y follow-up assessments. The primary outcome was global cognition (averaging z-scores across 11 tests). Secondary outcomes were episodic memory and executive function/attention. Repeated measures models were used to compare randomized groups.

RESULTS

Participants' mean age (standard deviation) was 69.6 (5.3); 49.2% were females. Daily supplementation with CE, compared with placebo, had no significant effect on 2-y change in global cognition {mean difference [95% confidence interval (CI)]: -0.01 (-0.08, 0.05) standard deviation units (SU)}. CE, compared with placebo, had no significant effects on 2-y change in episodic memory [mean difference (95% CI): -0.01 (-0.13, 0.10) SU] or executive function/attention [mean difference (95% CI): 0.003 (-0.07, 0.08) SU]. Subgroup analyses uncorrected for multiple-testing suggested cognitive benefits of CE supplementation, compared with placebo among those with poorer baseline diet quality.

CONCLUSIONS

Among 573 older adults who underwent repeat in-person, detailed neuropsychological assessments over 2 y, daily CE supplementation, compared with placebo, showed no overall benefits for global or domain-specific cognitive function. Possible cognitive benefits of CE among those with poorer diet quality warrant further study.

TRIAL REGISTRATION

This trial was registered at clinicaltrials.gov with identifier - NCT02422745.

The Mediterranean Diet, Cardiometabolic Biomarkers, and Risk of All-Cause Mortality: A 25-Year Follow-Up Study of the Women's Health Study

Background

Higher consumption of Mediterranean diet (MED) intake has been associated with reduced risk of all-cause mortality but limited data are available examining long-term outcomes in women or the underlying molecular mechanisms of this inverse association in human populations. We aimed to investigate the association of MED intake with long-term risk of all-cause mortality in women and to better characterize the relative contribution of traditional and novel cardiometabolic factors to the MED-related risk reduction in morality.

Methods

In a prospective cohort study of 25,315 initially healthy women from the Women's Health Study, we assessed dietary MED intake using a validated semiquantitative food frequency questionnaire according to the usual 9-category measure of MED adherence. Baseline levels of more than thirty cardiometabolic biomarkers were measured using standard assays and targeted nuclear magnetic resonance spectroscopy, including lipids, lipoproteins, apolipoproteins, inflammation, glucose metabolism and insulin resistance, branched-chain amino acids, small metabolites, and clinical factors. Mortality and cause of death was ascertained prospectively through medical and death records.

Results

During a mean follow-up of 25 years, 3,879 deaths were ascertained. Compared to the reference group of low MED intake (0-3, approximately the bottom tertile), and adjusting for age, treatment, and energy intake, risk reductions were observed for the middle and upper MED groups with respective HRs of 0.84 (95% CI 0.78-0.90) and 0.77 (95% CI 0.70-0.84), p for trend <0.0001. Further adjusting for smoking, physical activity, alcohol intake and menopausal factors attenuated the risk reductions which remained significant with respective HRs of 0.92 (95% CI 0.85-0.99) and 0.89 (95% CI 0.82-0.98), p for trend 0.0011. Risk reductions were generally similar for CVD and non-CVD mortality. Small molecule metabolites (e.g., alanine and homocysteine) and inflammation made the largest contributions to lower mortality risk (accounting for 14.8% and 13.0% of the benefit of the MED-mortality association, respectively), followed by triglyceride-rich lipoproteins (10.2%), adiposity (10.2%) and insulin resistance (7.4%), with lesser contributions (<3%) from other pathways including branched-chain amino acids, high-density lipoproteins, low-density lipoproteins, glycemic measures, and hypertension.

Conclusions

In the large-scale prospective Women's Health Study of 25,315 initially healthy US women followed for 25 years, higher MED intake was associated with approximately one fifth relative risk reduction in mortality. The inverse association was only partially explained by known novel and traditional cardiometabolic factors.

Polygenic Risk Score Predicts Sudden Death in Patients With Coronary Disease and Preserved Systolic Function

BACKGROUND

A familial predisposition to sudden and/or arrhythmic death (SAD) in the setting of coronary artery disease (CAD) exists; however, the genetic basis is poorly understood.

OBJECTIVES

The purpose of this study was to determine whether a genome-wide polygenic score for coronary artery disease (GPSCAD) might have utility in SAD risk stratification in CAD patients without severe systolic dysfunction.

METHODS

A previously validated GPSCAD was generated utilizing genome-wide genotyping in 4,698 PRE-DETERMINE participants of European ancestry with CAD and left ventricular ejection fraction >30%-35%. The population was dichotomized according to top GPSCAD decile as defined by the general population, and absolute, proportional, and relative risks for SAD and non-SAD were estimated using competing risk analyses.

RESULTS

Over a median follow-up of 8.0 years, participants in the top GPSCAD decile were at elevated absolute SAD risk (8.0%; 95% CI: 5.1%-12.4% vs 4.8%; 95% CI: 3.3%-7.0%; P = 0.005) and proportional SAD risk (29% vs 16%; P = 0.0003) compared with the remainder. After controlling for left ventricular ejection fraction, clinical factors, and electrocardiogram parameters, the top GPSCAD decile was associated with SAD (subdistribution HR: 1.77; 95% CI: 1.23-2.54; P = 0.002) but not non-SAD (subdistribution HR: 1.00; 95% CI: 0.80-1.25; P = 0.98) (P for Δ = 0.003). The addition of the top GPSCAD decile to the multivariable model significantly improved net reclassification indexes (NRIs) (continuous NRI: 14.0%; P = 0.024; and categorical NRI: 6.6%; P = 0.005) but not the C-index (difference in C-index: 0.007; P = 0.143).

CONCLUSIONS

Among CAD patients without severe systolic dysfunction, high GPSCAD specifically predicted SAD and enriched for both absolute and proportional SAD risk, identifying a population who might benefit from defibrillator therapy.

Arrhythmic sudden death survival prediction using deep learning analysis of scarring in the heart

Sudden cardiac death from arrhythmia is a major cause of mortality worldwide. Here, we develop a novel deep learning (DL) approach that blends neural networks and survival analysis to predict patient-specific survival curves from contrast-enhanced cardiac magnetic resonance images and clinical covariates for patients with ischemic heart disease. The DL-predicted survival curves offer accurate predictions at times up to 10 years and allow for estimation of uncertainty in predictions. The performance of this learning architecture was evaluated on multi-center internal validation data and tested on an independent test set, achieving concordance index of 0.83 and 0.74, and 10-year integrated Brier score of 0.12 and 0.14. We demonstrate that our DL approach with only raw cardiac images as input outperforms standard survival models constructed using clinical covariates. This technology has the potential to transform clinical decision-making by offering accurate and generalizable predictions of patient-specific survival probabilities of arrhythmic death over time.

Effect of cocoa flavanol supplementation for the prevention of cardiovascular disease events: the COcoa Supplement and Multivitamin Outcomes Study (COSMOS) randomized clinical trial

BACKGROUND

Cocoa extract is a source of flavanols that favorably influence vascular risk factors in small and short-term trials, yet effects on clinical cardiovascular events are untested.

OBJECTIVES

We examined whether cocoa extract supplementation decreases total cardiovascular disease (CVD) among older adults.

METHODS

We conducted a randomized, double-blind, placebo-controlled, 2-by-2 factorial trial of cocoa extract supplementation and multivitamins for prevention of CVD and cancer among 21,442 US adults (12,666 women aged ≥65 y and 8776 men aged ≥60 y), free of major CVD and recently diagnosed cancer. The intervention phase was June 2015 through December 2020. This article reports on the cocoa extract intervention. Participants were randomly assigned to a cocoa extract supplement [500 mg flavanols/d, including 80 mg (-)-epicatechin] or placebo. The primary outcome was a composite of confirmed incident total cardiovascular events, including myocardial infarction (MI), stroke, coronary revascularization, cardiovascular death, carotid artery disease, peripheral artery surgery, and unstable angina.

RESULTS

During a median follow-up of 3.6 y, 410 participants taking cocoa extract and 456 taking placebo had confirmed total cardiovascular events (HR: 0.90; 95% CI: 0.78, 1.02; P = 0.11). For secondary endpoints, HRs were 0.73 (95% CI: 0.54, 0.98) for CVD death, 0.87 (95% CI: 0.66, 1.16) for MI, 0.91 (95% CI: 0.70, 1.17) for stroke, 0.95 (95% CI: 0.77, 1.17) for coronary revascularization, neutral for other individual cardiovascular endpoints, and 0.89 (95% CI: 0.77, 1.03) for all-cause mortality. Per-protocol analyses censoring follow-up at nonadherence supported a lower risk of total cardiovascular events (HR: 0.85; 95% CI: 0.72, 0.99). There were no safety concerns.

CONCLUSIONS

Cocoa extract supplementation did not significantly reduce total cardiovascular events among older adults but reduced CVD death by 27%. Potential reductions in total cardiovascular events were supported in per-protocol analyses. Additional research is warranted to clarify whether cocoa extract may reduce clinical cardiovascular events. This trial is registered at www.clinicaltrials.gov as NCT02422745.

Multivitamins in the prevention of cancer and cardiovascular disease: the COcoa Supplement and Multivitamin Outcomes Study (COSMOS) randomized clinical trial

BACKGROUND

Although older adults commonly take multivitamin-multimineral (MVM) supplements to promote health, evidence on the use of daily MVMs on invasive cancer is limited.

OBJECTIVES

The study objective was to determine if a daily MVM decreases total invasive cancer among older adults.

METHODS

We performed a randomized, double-blind, placebo-controlled, 2-by-2 factorial trial of a daily MVM and cocoa extract for prevention of cancer and cardiovascular disease (CVD) among 21,442 US adults (12,666 women aged ≥65 y and 8776 men aged ≥60 y) free of major CVD and recently diagnosed cancer. The intervention phase was from June 2015 through December 2020. This article reports on the MVM intervention. Participants were randomly assigned to daily MVM or placebo. The primary outcome was total invasive cancer, excluding nonmelanoma skin cancer. Secondary outcomes included major site-specific cancers, total CVD, all-cause mortality, and total cancer risk among those with a baseline history of cancer.

RESULTS

During a median follow-up of 3.6 y, invasive cancer occurred in 518 participants in the MVM group and 535 participants in the placebo group (HR: 0.97; 95% CI: 0.86, 1.09; P = 0.57). We observed no significant effect of a daily MVM on breast cancer (HR: 1.06; 95% CI: 0.79, 1.42) or colorectal cancer (HR: 1.30; 95% CI: 0.80, 2.12). We observed a protective effect of a daily MVM on lung cancer (HR: 0.62; 95% CI: 0.42, 0.92). The composite CVD outcome occurred in 429 participants in the MVM group and 437 participants in the placebo group (HR: 0.98; 95% CI: 0.86, 1.12). MVM use did not significantly affect all-cause mortality (HR: 0.93; 95% CI: 0.81, 1.08). There were no safety concerns.

CONCLUSIONS

A daily MVM supplement, compared with placebo, did not significantly reduce the incidence of total cancer among older men and women. Future studies are needed to determine the effects of MVMs on other aging-related outcomes among older adults. This trial is registered at www.clinicaltrials.gov as NCT02422745.

Exercise-Induced Ventricular Ectopy and Cardiovascular Mortality in Asymptomatic Individuals

BACKGROUND

The prognosis of exercise-induced premature ventricular contractions (PVCs) in asymptomatic individuals is unclear.

OBJECTIVES

This study sought to investigate whether high-grade PVCs during stress testing predict mortality in asymptomatic individuals.

METHODS

A cohort of 5,486 asymptomatic individuals who took part in the Lipid Research Clinics prospective cohort had baseline interview, physical examination, blood tests, and underwent Bruce protocol treadmill testing. Adjusted Cox survival models evaluated the association of exercise-induced high-grade PVCs (defined as either frequent (>10 per minute), multifocal, R-on-T type, or ≥2 PVCs in a row) with all-cause and cardiovascular mortality.

RESULTS

Mean baseline age was 45.4 ± 10.8 years; 42% were women. During a mean follow-up of 20.2 ± 3.9 years, 840 deaths occurred, including 311 cardiovascular deaths. High-grade PVCs occurred during exercise in 1.8% of individuals, during recovery in 2.4%, and during both in 0.8%. After adjusting for age, sex, diabetes, hypertension, lipids, smoking, body mass index, and family history of premature coronary disease, high-grade PVCs during recovery were associated with cardiovascular mortality (hazard ratio [HR]: 1.82; 95% CI: 1.19-2.79; P = 0.006), which remained significant after further adjusting for exercise duration, heart rate recovery, achieving target heart rate, and ST-segment depression (HR: 1.68; 95% CI: 1.09-2.60; P = 0.020). Results were similar by clinical subgroups. High-grade PVCs occurring during the exercise phase were not associated with increased risk. Recovery PVCs did not improve 20-year cardiovascular mortality risk discrimination beyond clinical variables.

CONCLUSIONS

High-grade PVCs occurring during recovery were associated with long-term risk of cardiovascular mortality in asymptomatic individuals, whereas PVCs occurring only during exercise were not associated with increased risk.

Diabetes and Risk of Sudden Death in Coronary Artery Disease Patients Without Severe Systolic Dysfunction

OBJECTIVES

This study sought to determine the absolute and relative associations of diabetes mellitus (DM) and hemoglobin A1c (HbA1c) with sudden and/or arrhythmic death (SAD) versus other modes of death in patients with coronary artery disease (CAD) who do not qualify for implantable cardioverter-defibrillators.

BACKGROUND

Patients with CAD and DM are at elevated risk for SAD; however, it is unclear whether these patients would benefit from implantable cardioverter-defibrillators given competing causes of death and/or whether HbA1c might augment SAD risk stratification.

METHODS

In the PRE-DETERMINE study of 5,764 patients with CAD with left ventricular ejection fraction (LVEF) of >30% to 35%, competing risk analyses were used to compare the absolute and relative risks of SAD versus non-SAD by DM status and HbA1c level and to identify risk factors for SAD among 1,782 patients with DM.

RESULTS

Over a median follow-up of 6.8 years, DM and HbA1c were significantly associated with SAD and non-SAD (P < 0.05 for all comparisons); however, the cumulative incidence of non-SAD (19.2%; 95% CI: 17.3%-21.2%) was almost 4 times higher than SAD (4.8%; 95% CI: 3.8%-5.9%) in DM patients. A similar pattern of absolute risk was observed across categories of HbA1c. In analyses limited to patients with DM, HbA1c was not associated with SAD, whereas low LVEF, atrial fibrillation, and electrocardiogram measurements were associated with higher SAD risk.

CONCLUSIONS

In patients with CAD and LVEF of >30% to 35%, patients with DM and/or elevated HbA1c are at much higher absolute risk of dying from non-SAD than SAD. Clinical risk markers, and not HbA1c, were associated with SAD risk in patients with DM. (PRE-DETERMINE: Biologic Markers and MRI SCD Cohort Study; NCT01114269).

Association of Lipid, Inflammatory, and Metabolic Biomarkers With Age at Onset for Incident Coronary Heart Disease in Women

Importance

Risk profiles for premature coronary heart disease (CHD) are unclear.

Objective

To examine baseline risk profiles for incident CHD in women by age at onset.

Design, Setting, and Participants

A prospective cohort of US female health professionals participating in the Women's Health Study was conducted; median follow-up was 21.4 years. Participants included 28 024 women aged 45 years or older without known cardiovascular disease. Baseline profiles were obtained from April 30, 1993, to January 24, 1996, and analyses were conducted from October 1, 2017, to October 1, 2020.

Exposures

More than 50 clinical, lipid, inflammatory, and metabolic risk factors and biomarkers.

Main Outcomes and Measures

Four age groups were examined (<55, 55 to <65, 65 to <75, and ≥75 years) for CHD onset, and adjusted hazard ratios (aHRs) were calculated using stratified Cox proportional hazard regression models with age as the time scale and adjusting for clinical factors. Women contributed to different age groups over time.

Results

Of the clinical factors in the women, diabetes had the highest aHR for CHD onset at any age, ranging from 10.71 (95% CI, 5.57-20.60) at CHD onset in those younger than 55 years to 3.47 (95% CI, 2.47-4.87) at CHD onset in those 75 years or older. Risks that were also noted for CHD onset in participants younger than 55 years included metabolic syndrome (aHR, 6.09; 95% CI, 3.60-10.29), hypertension (aHR, 4.58; 95% CI, 2.76-7.60), obesity (aHR, 4.33; 95% CI, 2.31-8.11), and smoking (aHR, 3.92; 95% CI, 2.32-6.63). Myocardial infarction in a parent before age 60 years was associated with 1.5- to 2-fold risk of CHD in participants up to age 75 years. From approximately 50 biomarkers, lipoprotein insulin resistance had the highest standardized aHR: 6.40 (95% CI, 3.14-13.06) for CHD onset in women younger than 55 years, attenuating with age. In comparison, weaker but significant associations with CHD in women younger than 55 years were noted (per SD increment) for low-density lipoprotein cholesterol (aHR, 1.38; 95% CI, 1.10-1.74), non-high-density lipoprotein cholesterol (aHR, 1.67; 95% CI, 1.36-2.04), apolipoprotein B (aHR, 1.89; 95% CI, 1.52-2.35), triglycerides (aHR, 2.14; 95% CI, 1.72-2.67), and inflammatory biomarkers (1.2- to 1.8-fold)-all attenuating with age. Some biomarkers had similar CHD age associations (eg, physical inactivity, lipoprotein[a], total high-density lipoprotein particles), while a few had no association with CHD onset at any age. Most risk factors and biomarkers had associations that attenuated with increasing age at onset.

Conclusions and Relevance

In this cohort study, diabetes and insulin resistance, in addition to hypertension, obesity, and smoking, appeared to be the strongest risk factors for premature onset of CHD. Most risk factors had attenuated relative rates at older ages.

Effect of Marine Omega-3 Fatty Acid and Vitamin D Supplementation on Incident Atrial Fibrillation: A Randomized Clinical Trial

IMPORTANCE

Atrial fibrillation (AF) is the most common heart rhythm disturbance, continues to increase in incidence, and results in significant morbidity and mortality. The marine omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), and vitamin D have been reported to have both benefits and risks with respect to incident AF, but large-scale, long-term randomized trial data are lacking.

OBJECTIVE

To test the effects of long-term administration of marine omega-3 fatty acids and vitamin D on incident AF.

DESIGN, SETTING, AND PARTICIPANTS

An ancillary study of a 2 × 2 factorial randomized clinical trial involving 25 119 women and men aged 50 years or older without prior cardiovascular disease, cancer, or AF. Participants were recruited directly by mail between November 2011 and March 2014 from all 50 US states and were followed up until December 31, 2017.

INTERVENTIONS

Participants were randomized to receive EPA-DHA (460 mg/d of EPA and 380 mg/d of DHA) and vitamin D3 (2000 IU/d) (n = 6272 analyzed); EPA-DHA and placebo (n = 6270 analyzed); vitamin D3 and placebo (n = 6281 analyzed); or 2 placebos (n = 6296 analyzed).

MAIN OUTCOMES AND MEASURES

The primary outcome was incident AF confirmed by medical record review.

RESULTS

Among the 25 119 participants who were randomized and included in the analysis (mean age, 66.7 years; 50.8% women), 24 127 (96.1%) completed the trial. Over a median 5.3 years of treatment and follow-up, the primary end point of incident AF occurred in 900 participants (3.6% of study population). For the EPA-DHA vs placebo comparison, incident AF events occurred in 469 (3.7%) vs 431 (3.4%) participants, respectively (hazard ratio, 1.09; 95% CI, 0.96-1.24; P = .19). For the vitamin D3 vs placebo comparison, incident AF events occurred in 469 (3.7%) vs 431 (3.4%) participants, respectively (hazard ratio, 1.09; 95% CI, 0.96-1.25; P = .19). There was no evidence for interaction between the 2 study agents (P = .39).

CONCLUSIONS AND RELEVANCE

Among adults aged 50 years or older, treatment with EPA-DHA or vitamin D3, compared with placebo, resulted in no significant difference in the risk of incident AF over a median follow-up of more than 5 years. The findings do not support the use of either agent for the primary prevention of incident AF.

TRIAL REGISTRATION

ClinicalTrials.gov Identifiers: NCT02178410; NCT01169259.

Association of the Mediterranean Diet With Onset of Diabetes in the Women's Health Study

IMPORTANCE

Higher Mediterranean diet (MED) intake has been associated with reduced risk of type 2 diabetes, but underlying biological mechanisms are unclear.

OBJECTIVE

To characterize the relative contribution of conventional and novel biomarkers in MED-associated type 2 diabetes risk reduction in a US population.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study was conducted among 25 317 apparently healthy women. The participants with missing information regarding all traditional and novel metabolic biomarkers or those with baseline diabetes were excluded. Participants were invited for baseline assessment between September 1992 and May 1995. Data were collected from November 1992 to December 2017 and analyzed from December 2018 to December 2019.

EXPOSURES

MED intake score (range, 0 to 9) was computed from self-reported dietary intake, representing adherence to Mediterranean diet intake.

MAIN OUTCOMES AND MEASURES

Incident cases of type 2 diabetes, identified through annual questionnaires; reported cases were confirmed by either telephone interview or supplemental questionnaire. Proportion of reduced risk of type 2 diabetes explained by clinical risk factors and a panel of 40 biomarkers that represent different physiological pathways was estimated.

RESULTS

The mean (SD) age of the 25 317 female participants was 52.9 (9.9) years, and they were followed up for a mean (SD) of 19.8 (5.8) years. Higher baseline MED intake (score ≥6 vs ≤3) was associated with as much as a 30% lower type 2 diabetes risk (age-adjusted and energy-adjusted hazard ratio, 0.70; 95% CI, 0.62-0.79; when regression models were additionally adjusted with body mass index [BMI]: hazard ratio, 0.85; 95% CI, 0.76-0.96). Biomarkers of insulin resistance made the largest contribution to lower risk (accounting for 65.5% of the MED-type 2 diabetes association), followed by BMI (55.5%), high-density lipoprotein measures (53.0%), and inflammation (52.5%), with lesser contributions from branched-chain amino acids (34.5%), very low-density lipoprotein measures (32.0%), low-density lipoprotein measures (31.0%), blood pressure (29.0%), and apolipoproteins (23.5%), and minimal contribution (≤2%) from hemoglobin A1c. In post hoc subgroup analyses, the inverse association of MED diet with type 2 diabetes was seen only among women who had BMI of at least 25 at baseline but not those who had BMI of less than 25 (eg, women with BMI <25, age- and energy-adjusted HR for MED score ≥6 vs ≤3, 1.01; 95% CI, 0.77-1.33; P for trend = .92; women with BMI ≥25: HR, 0.76; 95% CI, 0.67-0.87; P for trend < .001).

CONCLUSIONS AND RELEVANCE

In this cohort study, higher MED intake scores were associated with a 30% relative risk reduction in type 2 diabetes during a 20-year period, which could be explained in large part by biomarkers of insulin resistance, BMI, lipoprotein metabolism, and inflammation.

Validation of electrocardiographic criteria for identifying left ventricular dysfunction in patients with previous myocardial infarction

Background

Eleven criteria correlating electrocardiogram (ECG) findings with reduced left ventricular ejection fraction (LVEF) have been previously published. These have not been compared head‐to‐head in a single study. We studied their value as a screening test to identify patients with reduced LVEF estimated by cardiac magnetic resonance (CMR) imaging.

Methods

ECGs and CMR from 548 patients (age 61 + 11 years, 79% male) with previous myocardial infarction (MI), from the DETERMINE and PRE‐DETERMINE studies, were analyzed. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of each criterion for identifying patients with LVEF ≤ 30% and ≤ 40% were studied. A useful screening test should have high sensitivity and NPV.

Results

Mean LVEF was 40% (SD = 11%); 264 patients (48.2%) had LVEF ≤ 40%, and 96 patients (17.5%) had LVEF ≤ 30%. Six of 11 criteria were associated with a significant lower LVEF, but had poor sensitivity to identify LVEF ≤ 30% (range 2.1%–55.2%) or LVEF ≤ 40% (1.1%–51.1%); NPVs were good for LVEF ≤ 30% (range 82.8%–85.9%) but not for LVEF ≤ 40% (range 52.1%–60.6%). Goldberger's third criterion (RV4/SV4 < 1) and combinations of maximal QRS duration > 124 ms + either Goldberger's third criterion or Goldberger's first criterion (SV1 or SV2 + RV5 or RV6 ≥ 3.5 mV) had high specificity (95.4%–100%) for LVEF ≤ 40%, although seen in only 48 (8.8%) patients; predictive values were similar on subgroup analysis.

Conclusions

None of the ECG criteria qualified as a good screening test. Three criteria had high specificity for LVEF ≤ 40%, although seen in < 9% of patients. Whether other ECG criteria can better identify LV dysfunction remains to be determined.

Markers of Myocardial Stress, Myocardial Injury, and Subclinical Inflammation and the Risk of Sudden Death

BACKGROUND

The majority of sudden cardiac deaths (SCDs) occur in low-risk populations often as the first manifestation of cardiovascular disease (CVD). Biomarkers are screening tools that may identify subclinical cardiovascular disease and those at elevated risk for SCD. We aimed to determine whether the total to high-density lipoprotein cholesterol ratio, high-sensitivity cardiac troponin I, NT-proBNP (N-terminal pro-B-type natriuretic peptide), or high-sensitivity C-reactive protein individually or in combination could identify individuals at higher SCD risk in large, free-living populations with and without cardiovascular disease.

METHODS

We performed a nested case-control study within 6 prospective cohort studies using 565 SCD cases matched to 1090 controls (1:2) by age, sex, ethnicity, smoking status, and presence of cardiovascular disease.

RESULTS

The median study follow-up time until SCD was 11.3 years. When examined as quartiles or continuous variables in conditional logistic regression models, each of the biomarkers was significantly and independently associated with SCD risk after mutually controlling for cardiac risk factors and other biomarkers. The mutually adjusted odds ratios for the top compared with the bottom quartile were 1.90 (95% CI, 1.30-2.76) for total to high-density lipoprotein cholesterol ratio, 2.59 (95% CI, 1.76-3.83) for high-sensitivity cardiac troponin I, 1.65 (95% CI, 1.12-2.44) for NT-proBNP, and 1.65 (95% CI, 1.13-2.41) for high-sensitivity C-reactive protein. A biomarker score that awarded 1 point when the concentration of any of those 4 biomarkers was in the top quartile (score range, 0-4) was strongly associated with SCD, with an adjusted odds ratio of 1.56 (95% CI, 1.37-1.77) per 1-unit increase in the score.

CONCLUSIONS

Widely available measures of lipids, subclinical myocardial injury, myocardial strain, and vascular inflammation show significant independent associations with SCD risk in apparently low-risk populations. In combination, these measures may have utility to identify individuals at risk for SCD.

Circulating miRNAs and Risk of Sudden Death in Patients With Coronary Heart Disease

OBJECTIVES

This study evaluated whether plasma miRNAs were specifically associated with sudden cardiac and/or arrhythmic death (SCD) in a cohort of patients with coronary heart disease (CHD), most of whom were without primary prevention implantable cardioverter-defibrillators.

BACKGROUND

Novel biomarkers for sudden death risk stratification are needed in patients with CHD to more precisely target preventive therapies, such as implantable cardioverter-defibrillators. miRNAs have been implicated in regulating inflammation and cardiac fibrosis in cells, and plasma miRNAs have been shown to predict cardiovascular death in patients with CHD.

METHODS

We performed a nested case control study within a multicenter cohort of 5,956 patients with CHD followed prospectively for SCD. Plasma levels of 18 candidate miRNAs previously associated with cardiac remodeling were measured in 129 SCD cases and 258 control subjects matched on age, sex, race, and left ventricular ejection fraction.

RESULTS

miR-150-5p, miR-29a-3p, and miR-30a-5p were associated with increased SCD risk (odds ratios and 95% confidence intervals: 2.03 [1.12 to 3.67]; p = 0.02; 1.93 [1.07 to 3.50]; p = 0.02; 0.55 [0.31 to 0.97]; p = 0.04, respectively, for third vs. first tertile miRNA level). Unfavorable levels of all 3 miRNAs was associated with a 4.8-fold increased SCD risk (1.59 to 14.51; p = 0.006). A bioinformatics-based approach predicted miR-150-5p, miR-29a-3p, and miR-30a-5p to be involved in apoptosis, fibrosis, and inflammation.

CONCLUSIONS

These findings suggest that plasma miRNAs may regulate pathways important for remodeling and may be useful in identifying patients with CHD at increased risk of SCD.

Sudden Death in Patients With Coronary Heart Disease Without Severe Systolic Dysfunction

Importance

The majority of sudden and/or arrhythmic deaths (SAD) in patients with coronary heart disease occur in those without severe systolic dysfunction, for whom strategies for sudden death prevention are lacking.

Objective

To provide contemporary estimates of SAD vs other competing causes of death in patients with coronary heart disease without severe systolic dysfunction to search for high-risk subgroups that might be targeted in future trials of SAD prevention.

Design, Setting, and Participants

This prospective observational cohort study included 135 clinical sites in the United States and Canada. A total of 5761 participants with coronary heart disease who did not qualify for primary prevention implantable cardioverter defibrillator therapy based on left ventricular ejection fraction (LVEF) of more than 35% or New York Heart Association (NYHA) heart failure class (LVEF >30%, NYHA I).

Exposures

Clinical risk factors measured at baseline including age, LVEF, and NYHA heart failure class.

Main Outcomes and Measures

Primary outcome of SAD, which is a composite of SAD and resuscitated ventricular fibrillation arrest.

Results

The mean (SD) age of the cohort was 64 (11) years. During a median of 3.9 years, the cumulative incidence of SAD and non-SAD was 2.1% and 7.7%, respectively. Sudden and/or arrhythmic death was the most common mode of cardiovascular death accounting for 114 of 202 cardiac deaths (56%), although noncardiac death was the primary mode of death in this population. The 4-year cumulative incidence of SAD was lowest in those with an LVEF of more than 60% (1.0%) and highest among those with LVEF of 30% to 40% (4.9%) and class III/IV heart failure (5.1%); however, the cumulative incidence of non-SAD was similarly elevated in these latter high-risk subgroups. Patients with a moderately reduced LVEF (40%-49%) were more likely to die of SAD, whereas those with class II heart failure and advancing age were more likely to die of non-SAD. The proportion of deaths due to SAD varied widely, from 14% (18 of 131 deaths) in patients with NYHA II to 49% (37 of 76 deaths) in those younger than 60 years.

Conclusions and Relevance

In a contemporary population of patients with coronary heart disease without severe systolic dysfunction, SAD accounts for a significant proportion of overall mortality. Moderately reduced LVEF, age, and NYHA class distinguished SAD and non-SAD, whereas other markers were equally associated with both modes of death. Absolute and proportional risk of SAD varied significantly across clinical subgroups, and both will need to be maximized in future risk stratification efforts.

COMT and Alpha-Tocopherol Effects in Cancer Prevention: Gene-Supplement Interactions in Two Randomized Clinical Trials

BACKGROUND

Vitamins are among the most frequently used supplements (48% of US adults). However, little is known about contributions of genetic variation to their efficacy and safety. Multiple pathways link catechol-O-methyltransferase (COMT) to the vitamin E supplement, alpha-tocopherol, and cancer.

METHODS

Here we determined if COMT exerted pharmacogenetic effects on cancer prevention in two randomized trials of alpha-tocopherol supplementation. Pharmacogenetic effects of common COMT rs4680 (val158met), which encodes a nonsynonymous valine-to-methionine substitution, were examined in the trial plus a 10-year post-trial follow-up (overall) period of The Women's Genome Health Study (WGHS, N = 23 294), a 10-year alpha-tocopherol and aspirin trial with 10 years post-trial follow-up. Results were validated in a case/control (N = 2396/2235) subset of the Alpha-Tocopherol Beta-Carotene Cancer Prevention Study (ATBC, N = 29 133). The primary outcome was total cancers. Rates of cancer types prevalent in women (colorectal, breast, lung, uterine, and lymphoma/leukemia) were also examined. All statistical tests were two-sided.

RESULTS

Random-effects meta-analysis of rs4680 genotype strata, in WGHS and ATBC overall periods, revealed differential alpha-tocopherol effects compared with placebo: met/met (hazard ratio [HR] = 0.88; 95% confidence interval [CI] = 0.80 to 0.97; P = .01), val/met (HR = 0.99; 95% CI = 0.92 to 1.06; P = .74), and val/val (HR = 1.18; 95% CI = 1.06 to 1.31; P = .002) with a statistically significant COMT by alpha-tocopherol interaction (Pinteraction <.001). Timing of effects differed, with stronger effects in WGHS trial and ATBC post-trial.

CONCLUSION

Pharmacogenetic analysis of COMT and cancer prevention in two large randomized trials revealed statistically significant COMT by alpha-tocopherol interaction, such that alpha-tocopherol was beneficial among rs4680 met-allele (28.0%), but not val-allele (22.8%) homozygotes. These effects indicate the need for additional studies of genetic variation as a determinant of the benefits and possible harms of over-the-counter supplements, like alpha-tocopherol, used for health promotion.

Association of Nonfasting vs Fasting Lipid Levels With Risk of Major Coronary Events in the Anglo-Scandinavian Cardiac Outcomes Trial-Lipid Lowering Arm

IMPORTANCE

Recent guidelines have recommended nonfasting for routine testing of lipid levels based on comparisons of nonfasting and fasting populations. However, no previous study has examined the association of cardiovascular outcomes with fasting vs nonfasting lipid levels measured in the same individuals.

OBJECTIVE

To compare the association of nonfasting and fasting lipid levels with prospectively ascertained coronary and vascular outcomes and to evaluate whether a strategy of using nonfasting instead of fasting lipid level measurement would result in misclassification of risk for individuals undergoing evaluation for initiation of statin therapy.

DESIGN, SETTING, AND PARTICIPANTS

This post hoc prospective follow-up of a randomized clinical trial included 8270 of 10 305 participants from the Anglo-Scandinavian Cardiac Outcomes Trial-Lipid Lowering Arm (ASCOT-LLA) with nonfasting and fasting lipid levels measured 4 weeks apart (including 6855 participants with no prior vascular disease) (median follow-up, 3.3 years; interquartile range, 2.8-3.6 years). Data were collected from February 1, 1998, to December 31, 2002, and analyzed from February 1, 2016, to November 30, 2018. Multivariable Cox models, adjusted for cardiovascular risk factors, were calculated for 40-mg/dL (1-mmol/L) higher values of nonfasting and fasting lipids.

MAIN OUTCOMES AND MEASURES

The trial's primary end point consisted of major coronary events (nonfatal myocardial infarction [MI] and fatal coronary heart disease [212 events]). Secondary analyses examined atherosclerotic cardiovascular disease (ASCVD) events (including MI, stroke, and ASCVD death [351 events]).

RESULTS

Among the 8270 participants (82.1% male; mean [SD] age, 63.4 [8.5] years), nonfasting samples had modestly higher triglyceride levels and similar cholesterol levels compared to fasting samples. Associations of nonfasting lipid levels with coronary events were similar to those for fasting lipid levels. For example, adjusted hazard ratios (HRs) per 40-mg/dL of low-density lipoprotein cholesterol were 1.32 (95% CI, 1.08-1.61; P = .007) for nonfasting levels and 1.28 (95% CI, 1.07-1.55; P = .008) for fasting levels. For the primary prevention group, adjusted HRs were 1.42 (95% CI, 1.13-1.78; P = .003) for nonfasting levels and 1.37 (95% CI, 1.11-1.69; P = .003) for fasting levels. Results were consistent by randomized treatment arm (atorvastatin calcium, 10 mg/d, or placebo) and similar for ASCVD events. Concordance of fasting and nonfasting lipid levels for classifying participants into appropriate ASCVD risk categories was high (94.8%).

CONCLUSIONS AND RELEVANCE

Measurement of nonfasting and fasting lipid levels yields similar results in the same individuals for association with incident coronary and ASCVD events. These results suggest that routine measurement of nonfasting lipid levels may help facilitate ASCVD risk screening and treatment, including consideration of when to initiate statin therapy.

COMT Effects on Vitamin E and Colorectal Cancer, in-vitro and in Two Randomized Trials (P15-005-19)

Objectives

Despite promising observational data and compelling mechanisms of action, vitamin E has failed to demonstrate evidence of benefit in randomized clinical trials (RCTs). In two large long-term placebo-controlled RCTs, we reported that vitamin E effects on total cancer were modified by genetic variation in catechol-O-methyltransferase (COMT), an enzyme that metabolizes catecholamines. Here we investigate COMT effects on colorectal cancer (CRC) in the two RCTs and a CRC cell line.

Methods

We analyzed COMT rs4680 association with rates of CRC in the Women's Health Study (WHS), N = 23,294 and a case/control (N = 2396/2235) subset of the Alpha-Tocopherol Beta-Carotene Cancer Prevention Study (ATBC). Cell survival and apoptosis were examined in-vitro in HCT116 cells treated with increasing doses of vitamin E when COMT gene expression was inhibited by silencing RNA (siRNA).

Results

Rates of CRC were higher with randomized vitamin E compared to placebo among COMT high-activity val/val homozygotes in ATBC (HR, [CI] = 3.00, [1.48–6.09]), but not WHS (HR, [CI] = 0.99, [0.63–1.57]). Among low-activity met/met homozygotes randomized to vitamin E compared to placebo, rates of CRC were borderline lower in WHS (HR, [CI] = 0.66, [0.44–1.01]), but not in ATBC (HR, [CI] = 0.93, [0.63–1.62]).

In cell culture, vitamin E at 3 µg/ml and 10 µg/mL had no effect on cell viability or apoptosis. However, silencing COMT resulted in a modest apoptotic effect that vitamin E enhanced in a dose-dependent manner. Human apoptosis arrays indicated that in the absence of COMT expression, vitamin E induced protein expression related to the intrinsic apoptotic pathway through p53 activation, dysregulation of Bcl-2 family protein expression and down-regulation of IAP family protein expression.

Conclusions

Differential COMT effects on vitamin E and CRC were similar to those previously reported for all invasive cancers, but were only significant for val/val homozygotes. Further, inhibiting COMT in the presence of vitamin E in a CRC in-vitro model, recapitulated the RCT observation that among individuals homozygous for the low-activity allele (met/met) vitamin E tended to reduce invasive cancer and here CRC.

Funding Sources

National Institutes of Health: NCI and NHLBI.

Premature Myocardial Infarction in the Middle East and North Africa: Rationale for the Gulf PREVENT Study

The Middle East and North Africa (MENA) region has a high burden of morbidity and mortality due to premature (≤55 years in men; ≤65 years in women) myocardial infarction (MI) and acute coronary syndrome (ACS). Despite this, the prevalence of risk factors in patients presenting with premature MI or ACS is incompletely described. We compared lifestyle, clinical risk factors, and biomarkers associated with premature MI/ACS in the MENA region with selected non-MENA high-income countries. We identified English-language, peer-reviewed publications through PubMed (up to March 2018). We used the World Bank classification system to categorize countries. Patients with premature MI/ACS in the MENA region had a higher prevalence of smoking than older patients with MI/ACS but a lower prevalence of diabetes, hypertension, and dyslipidemia. Men with premature MI/ACS had a higher prevalence of smoking than women but a lower prevalence of diabetes and hypertension. The MENA region had sparse data on lifestyle, diet, psychological stress, and physical activity. To address these knowledge gaps, we initiated the ongoing Gulf Population Risks and Epidemiology of Vascular Events and Treatment (Gulf PREVENT) case-control study to improve primary and secondary prevention of premature MI in the United Arab Emirates, a high-income country in the MENA region.

Assessment of Risk Factors and Biomarkers Associated With Risk of Cardiovascular Disease Among Women Consuming a Mediterranean Diet

IMPORTANCE

Higher Mediterranean diet (MED) intake has been associated with lower risk of cardiovascular disease (CVD), but limited data are available about the underlying molecular mechanisms of this inverse disease association in human populations.

OBJECTIVE

To better characterize the relative contribution of traditional and novel factors to the MED-related risk reduction in CVD events in a US population.

DESIGN, SETTING, AND PARTICIPANTS

Using a prospective cohort design, baseline MED intake was assessed in 25 994 initially healthy US women in the Women's Health Study who were followed up to 12 years. Potential mediating effects of a panel of 40 biomarkers were evaluated, including lipids, lipoproteins, apolipoproteins, inflammation, glucose metabolism and insulin resistance, branched-chain amino acids, small-molecule metabolites, and clinical factors. Baseline study information and samples were collected between April 30, 1993, and January 24, 1996. Analyses were conducted between August 1, 2017, and October 30, 2018.

EXPOSURES

Intake of MED is a 9-category measure of adherence to a Mediterranean dietary pattern. Participants were categorized into 3 levels based on their adherence to the MED.

MAIN OUTCOMES AND MEASURES

Incident CVD confirmed through medical records and the proportion of CVD risk reduction explained by mediators.

RESULTS

Among 25 994 women (mean [SD] age, 54.7 [7.1] years), those with low, middle, and upper MED intakes composed 39.0%, 36.2%, and 24.8% of the study population and experienced 428 (4.2%), 356 (3.8%), and 246 (3.8%) incident CVD events, respectively. Compared with the reference group who had low MED intake, CVD risk reductions were observed for the middle and upper groups, with respective HRs of 0.77 (95% CI, 0.67-0.90) and 0.72 (95% CI, 0.61-0.86) (P for trend < .001). The largest mediators of the CVD risk reduction of MED intake were biomarkers of inflammation (accounting for 29.2% of the MED-CVD association), glucose metabolism and insulin resistance (27.9%), and body mass index (27.3%), followed by blood pressure (26.6%), traditional lipids (26.0%), high-density lipoprotein measures (24.0%) or very low-density lipoprotein measures (20.8%), with lesser contributions from low-density lipoproteins (13.0%), branched-chain amino acids (13.6%), apolipoproteins (6.5%), or other small-molecule metabolites (5.8%).

CONCLUSIONS AND RELEVANCE

In this study, higher MED intake was associated with approximately one-fourth relative risk reduction in CVD events, which could be explained in part by known risk factors, both traditional and novel.

Strength Training and the Risk of Type 2 Diabetes and Cardiovascular Disease

PURPOSE

This study aimed to examine the association of strength training with incident type 2 diabetes and cardiovascular disease risk.

METHODS

We followed 35,754 healthy women (mean age = 62.6 yr, range = 47.0-97.8) from the Women's Health Study, who responded to a health questionnaire that included physical activity questions in 2000, assessing health outcomes through annual health questionnaire through 2014 (mean ± SD follow-up = 10.7 ± 3.7 yr). Incident type 2 diabetes (N cases = 2120) and cardiovascular disease (N cases = 1742) were confirmed on medical record review. Cases of cardiovascular disease were defined as confirmed cases of myocardial infarction, stroke, coronary artery bypass graft, angioplasty, or cardiovascular disease death.

RESULTS

Compared with women who reported no strength training, women engaging in any strength training experienced a reduced rate of type 2 diabetes of 30% (hazard ratio = 0.70, 95% confidence interval = 0.61-0.80) when controlling for time spent in other activities and other confounders. A risk reduction of 17% was observed for cardiovascular disease among women engaging in strength training (hazard ratio = 0.83, 95% confidence interval = 0.72, 0.96). Participation in both strength training and aerobic activity was associated with additional risk reductions for both type 2 diabetes and cardiovascular disease compared with participation in aerobic activity only.

CONCLUSIONS

These data support the inclusion of muscle-strengthening exercises in physical activity regimens for reduced risk of type 2 diabetes and cardiovascular disease, independent of aerobic exercise. Further research is needed to determine the optimum dose and intensity of muscle-strengthening exercises.

Menopausal age, postmenopausal hormone therapy and incident atrial fibrillation

OBJECTIVE

Limited data exist on the association between menopause and atrial fibrillation (AF). We sought to examine the relationship between menopausal age, postmenopausal hormone therapy (PHT) use and incident AF.

METHODS

The Women's Health Study (WHS) enrolled 39 876 female health professionals between 1992 and 1995. We prospectively examined 30 034 women in WHS using Cox proportional-hazard models. Participants were free of cardiovascular disease and AF at baseline and had not undergone hysterectomy without bilateral oophorectomy prior to menopause. Incident AF was confirmed by medical record review.

RESULTS

At baseline, median age was 53 years (IQR 49-60), median menopausal age was 50 years (IQR 46-52) and 14 415 (48.0%) had prior PHT use. Over a median follow-up of 20.5 years, 1350 AF events occurred. In multivariable analysis, relative hazards for AF were lower among women with younger age at menopause but did not differ significantly from women with the oldest menopausal age (<45: HR 0.82, 95% CI 0.67 to 1.02; 45-49: HR 0.90, 95% CI 0.74 to 1.08; 50-54: HR 0.89, 95% CI 0.75 to 1.06; >54 years: referent). Use of oestrogen-alone PHT, but not oestrogen and progesterone, was independently associated with AF risk (HR 1.22; 95% CI 1.02 to 1.45 vs HR 1.04; 95% CI 0.86 to 1.26). This relationship was not attenuated by intermediary cardiovascular events.

CONCLUSIONS

In this large prospective study, menopausal age was not significantly related to incident AF, while use of oestrogen monotherapy was associated with increased AF risk. Our findings suggest a pathophysiological link between unopposed oestrogen exposure and AF in women.

CLINICAL TRIAL REGISTRATION

NCT000000479; Post-results.

Modifiable Risk Factors for Incident Heart Failure in Atrial Fibrillation

OBJECTIVES

This study sought to identify modifiable risk factors and estimate the impact of risk factor modification on heart failure (HF) risk in women with new-onset atrial fibrillation (AF).

BACKGROUND

Incident HF is the most common nonfatal event in patients with AF, although strategies for HF prevention are lacking.

METHODS

We assessed 34,736 participants in the Women's Health Study who were free of prevalent cardiovascular disease at baseline. Cox models with time-varying assessment of risk factors after AF diagnosis were used to identify significant modifiable risk factors for incident HF.

RESULTS

Over a median follow-up of 20.6 years, 1,495 women developed AF without prevalent HF. In multivariable models, new-onset AF was associated with an increased risk of HF (hazard ratio [HR]: 9.03; 95% confidence interval [CI]: 7.52 to 10.85). Once women with AF developed HF, all-cause (HR: 1.83; 95% CI: 1.37 to 2.45) and cardiovascular mortality (HR: 2.87; 95% CI: 1.70 to 4.85) increased. In time-updated, multivariable models accounting for changes in risk factors after AF diagnosis, systolic blood pressure >120 mm Hg, body mass index ≥30 kg/m², current tobacco use, and diabetes mellitus were each associated with incident HF. The combination of these 4 modifiable risk factors accounted for an estimated 62% (95% CI: 23% to 83%) of the population-attributable risk of HF. Compared with women with 3 or 4 risk factors, those who maintained or achieved optimal risk factor control had a progressive decreased risk of HF (HR for 2 risk factors: 0.60; 95% CI: 0.37 to 0.95; 1 risk factor: 0.40; 95% CI: 0.25 to 0.63; and 0 risk factors: 0.14; 95% CI: 0.07 to 0.29).

CONCLUSIONS

In women with new-onset AF, modifiable risk factors including obesity, hypertension, smoking, and diabetes accounted for the majority of the population risk of HF. Optimal levels of modifiable risk factors were associated with decreased HF risk. Prospective assessment of risk factor modification at the time of AF diagnosis may warrant future investigation.

Association of N-Linked Glycoprotein Acetyls and Colorectal Cancer Incidence and Mortality

Background

Acute phase proteins highlight the dynamic interaction between inflammation and oncogenesis. GlycA, a novel nuclear magnetic resonance (NMR) inflammatory marker that identifies primarily circulating N-acetyl glycan groups attached to acute phase proteins, may be a future CRC risk biomarker.

Methods

We examined the association between GlycA and incident CRC and mortality in two prospective cohorts (N = 34,320); Discovery cohort: 27,495 participants from Women's Health Study (WHS); Replication cohort: 6,784 participants from Multi-Ethnic Study of Atherosclerosis (MESA). Multivariable Cox models were adjusted for clinical risk factors and compared GlycA to acute phase proteins (high-sensitivity C-reactive protein [hsCRP], fibrinogen, and soluble intercellular adhesion molecule-1 [sICAM-1]).

Results

In WHS (median follow-up 19 years, 337 cases, 103 deaths), adjusted HRs (95% CIs) per SD increment of GlycA for CRC incidence and mortality were 1.19 (1.06–1.35; p = 0.004) and 1.24 (1.00–1.55; p = 0.05), respectively. We replicated findings in MESA (median follow-up 11 years, 70 cases, 23 deaths); HRs (95% CIs) per SD of GlycA for CRC incidence and mortality were 1.32 (1.06–1.65; p = 0.01) and 1.54 (1.06–2.23; p = 0.02), respectively, adjusting for age, sex, and race. Pooled analysis, adjusted HR (95% CI) per SD of GlycA for CRC incidence and mortality was 1.26 (1.15–1.39; p = 1 x 10⁻⁶). Other acute phase proteins (hsCRP, fibrinogen, and sICAM-1) had weaker or no association with CRC incidence, while only fibrinogen and GlycA were associated with CRC mortality.

Conclusions

The clinical utility of GlycA to personalize CRC therapies or prevention warrants further study.

Trial Registration

ClinicalTrials.gov: WHS NCT00000479, MESA NCT00005487

Hemoglobin A1c levels and risk of sudden cardiac death: A nested case-control study

BACKGROUND

Sudden cardiac death (SCD) is often the first manifestation of cardiovascular disease (CVD), and preventive strategies within this broad population are lacking. Patients with diabetes represent a high-risk subgroup, but few data exist regarding whether measures of glycemia mediate risk and/or add to SCD risk stratification.

OBJECTIVE

The purpose of this study was to examine the association between hemoglobin A_1c (HbA_1c) and SCD.

METHODS

We performed a case-control analysis among individuals enrolled in 6 prospective cohort studies. HbA_1c levels were determined for 482 cases of SCD and 914 matched controls. Conditional logistic regression with fixed effects meta-analysis was used for analysis.

RESULTS

In multivariable models, HbA_1c levels were linearly associated with SCD risk over follow-up of 11.3 years (P <.001). Each 1% increment in HbA_1c was associated with a hazard ratio (HR) of 1.32 (95% confidence interval [CI] 1.16-1.50). The magnitude of the association was greater in subjects without vs those with known CVD [HR per 1% increment 1.64 (95% CI 1.31-2.06) vs 1.15 (95% CI 0.99-1.33), P interaction = .009]. In models simultaneously controlling for diabetes status and HbA_1c, the association between HbA_1c and SCD remained significant (HR 1.29, 95% CI 1.07-1.55, P = .01), whereas the association between diabetes and SCD was attenuated (relative risk 1.21, 95% CI 0.64-2.27, P = .56).

CONCLUSION

In these prospective cohorts, HbA_1c levels associated with SCD risk, particularly among those without known CVD, even after controlling for diabetes status. These data support the hypothesis that hyperglycemia mediates SCD risk among patients with diabetes.

Lipid biomarkers and long-term risk of cancer in the Women's Health Study

BACKGROUND

Lipid biomarkers, such as HDL-cholesterol concentrations, have been shown to have positive, inverse, and null associations with total, breast, and colorectal cancer risks. Studies of novel lipid biomarkers, such as apolipoprotein A-I (apo A-I) and apolipoprotein B-100 (apo B-100), and cancer risk have been sparse, to our knowledge.

OBJECTIVES

We evaluated the prospective association of total, breast, colorectal, and lung cancers and cancer mortality with circulating lipid biomarkers in 15,602 female health professionals in the Women's Health Study (aged ≥45 y, free of cardiovascular disease and cancer, and without hormone replacement therapy or lipid-lowering medications at baseline).

DESIGN

Cox regression models estimated HRs of cancer endpoints (19 y median follow-up) across quartiles 1 (reference) to 4 of each lipid biomarker after adjustment for cancer risk factors.

RESULTS

Confirmed cases included 2163 incident cancer cases (864 breast, 198 colorectal, and 190 lung cancers) and 647 cancer deaths. Total cancer risk was significantly lower in the highest quartile of apo A-I (adjusted HR: 0.79; 95% CI: 0.70, 0.90; P-trend = 0.0008) and HDL cholesterol (HR: 0.85; 95% CI: 0.75, 0.97; P-trend = 0.01). For site-specific cancers, significant associations included colorectal cancer risk with HDL cholesterol (HR: 0.63; 95% CI; 0.41, 0.98; P-trend = 0.03), triglycerides (HR: 1.86; 95% CI: 1.17, 2.97; P-trend = 0.02), and apo B-100 (HR: 1.60; 95% CI: 1.03, 2.49; P-trend = 0.006) and lung cancer risk with HDL cholesterol (HR: 0.59; 95% CI: 0.38, 0.93; P-trend = 0.01). LDL cholesterol was not significantly associated with risk of total cancer or any site-specific cancers. In time-dependent models that were adjusted for the use of a lipid-lowering medication after baseline, these associations remained.

CONCLUSIONS

Lipids were associated with total, lung, and colorectal cancer risks in women. Lifestyle interventions for heart-disease prevention, which reduce apo B-100 or raise HDL cholesterol, may be associated with reduced cancer risk. The Women's Health Study was registered at clinicaltrials.gov as NCT00000479.

Circulating N-Linked Glycoprotein Acetyls and Longitudinal Mortality Risk

RATIONALE

Circulating glycoprotein N-acetyl glucosamine residues have recently been associated with incident cardiovascular disease and diabetes mellitus.

OBJECTIVE

Using a plasma glycan biosignature (GlycA) to identify circulating N-acetyl glycan groups, we examined the longitudinal association between GlycA and mortality among initially healthy individuals.

METHODS AND RESULTS

We quantified GlycA by 400 MHz (1)H nuclear magnetic resonance spectroscopy in 27,524 participants in the Women's Health Study (NCT00000479). The primary outcome was all-cause mortality. We replicated the findings in an independent cohort of 12,527 individuals in the Justification for the Use of statins in Prevention: an Intervention Trial Evaluating Rosuvastatin (JUPITER) trial (NCT00239681). We also undertook secondary examination of cardiovascular disease and cancer mortality in the Women's Health Study. In the Women's Health Study, during 524,515 person-years of follow-up (median, 20.5 years), there were 3523 deaths. Risk factor-adjusted multivariable Cox proportional hazard ratio (95% confidence interval) per SD increment in GlycA for all-cause mortality was significantly increased at 5 years (1.21 [1.06-1.40]) and during maximal follow-up (1.14 [1.09-1.16]). Similar risk for all-cause mortality was observed in the replication cohort (1.33 [1.21-1.45]). In the Women's Health Study, risk of cardiovascular disease mortality was increased at 5 years (1.43 [1.05-1.95]) and during maximal follow-up (1.15 [1.04-1.26]) and of cancer mortality at 5 years (1.23 [1.02-1.47]) and during maximal follow-up (1.08 [1.01-1.16]). Examination of correlations and mortality associations adjusted for high-sensitivity C-reactive protein, fibrinogen, and intercellular adhesion molecule-1, suggested that GlycA reflects summative risk related to multiple pathways of systemic inflammation.

CONCLUSIONS

Among initially healthy individuals, elevated baseline circulating glycoprotein N-acetyl methyl groups were associated with longitudinal risk of all-cause, cardiovascular, and cancer mortality.

Dietary Fat Intake Is Differentially Associated with Risk of Paroxysmal Compared with Sustained Atrial Fibrillation in Women

BACKGROUND

Dietary fats have effects on biological pathways that may influence the development and maintenance of atrial fibrillation (AF). However, associations between n-3 (ω-3) polyunsaturated fatty acids and AF are inconsistent, and data on other dietary fats and AF risk are sparse.

OBJECTIVES

We examined the association between dietary fatty acid (FA) subclasses and risk of incident AF and explored whether these associations differed for sustained and paroxysmal AF.

METHODS

We conducted a prospective cohort study in 33,665 women ≥45 y old without cardiovascular disease (CVD) and AF at baseline in 1993. Fat intake was estimated from food frequency questionnaires at baseline and in 2004. Incident AF was confirmed by medical records through October 2013. AF patterns were classified according to the most sustained form of AF within 2 y of diagnosis. Cox proportional hazards models with the use of a competing risk model approach estimated the RR.

RESULTS

Over 19.2 y, 1441 cases of incident AF (929 paroxysmal and 467 persistent/chronic) were confirmed. Intakes of total fat and FA subclasses were not associated with risk of AF. Saturated fatty acids (SFAs) and monounsaturated fatty acids (MUFAs) were differentially associated with AF patterns. The RR for a 5% increment of energy from SFAs was 1.47 (95% CI: 1.04, 2.09) for persistent/chronic and 0.85 (95% CI: 0.66, 1.08) for paroxysmal AF (P-difference = 0.01). For MUFAs, the RR for a 5% increment was 0.67 (95% CI: 0.46, 0.98) for persistent/chronic and 1.03 (95% CI: 0.78, 1.34) for paroxysmal AF, although the difference between patterns was not significant (P-difference = 0.07).

CONCLUSIONS

Dietary fat was not associated with risk of incident AF in women without established CVD or AF. High SFA and low MUFA intakes were associated with greater risk of persistent or chronic, but not paroxysmal, AF. Improving dietary fat quality may play a role in the prevention of sustained forms of AF. The Women's Health Study was registered at clinicaltrials.gov as NCT00000479.

Identifying an Optimal Cutpoint for the Diagnosis of Hypertriglyceridemia in the Nonfasting State

BACKGROUND

Nonfasting triglycerides are similar or superior to fasting triglycerides at predicting cardiovascular events. However, diagnostic cutpoints are based on fasting triglycerides. We examined the optimal cutpoint for increased nonfasting triglycerides.

METHODS

We obtained baseline nonfasting (<8 h since last meal) samples from 6391 participants in the Women's Health Study who were followed prospectively for ≤17 years. The optimal diagnostic threshold for nonfasting triglycerides, determined by logistic regression models by use of c-statistics and the Youden index (sum of sensitivity and specificity minus 1), was used to calculate hazard ratios (HRs) for incident cardiovascular events. Performance was compared to thresholds recommended by the American Heart Association (AHA) and European guidelines.

RESULTS

The optimal threshold was 175 mg/dL (1.98 mmol/L), with a c-statistic of 0.656, statistically better than the AHA cutpoint of 200 mg/dL (c-statistic 0.628). For nonfasting triglycerides above and below 175 mg/dL, after adjusting for age, hypertension, smoking, hormone use, and menopausal status, the HR for cardiovascular events was 1.88 (95% CI 1.52-2.33, P < 0.001), and for triglycerides measured at 0-4 and 4-8 h since the last meal, 2.05 (1.54- 2.74) and 1.68 (1.21-2.32), respectively. We validated performance of this optimal cutpoint by use of 10-fold cross-validation and bootstrapping of multivariable models that included standard risk factors plus total and HDL cholesterol, diabetes, body mass index, and C-reactive protein.

CONCLUSIONS

In this study of middle-aged and older apparently healthy women, we identified a diagnostic threshold for nonfasting hypertriglyceridemia of 175 mg/dL (1.98 mmol/L), with the potential to more accurately identify cases than the currently recommended AHA cutpoint.

Association between plasma adiponectin levels and colorectal cancer risk in women

BACKGROUND

Adiponectin, an adipocyte-secreted hormone, has insulin-sensitizing characteristics. It remains unclear whether adiponectin may influence colorectal cancer development.

METHODS

To determine whether prediagnostic levels of adiponectin were associated with risk of incident colorectal cancer in the Women's Health Study, we conducted a nested case-control study of 275 colorectal cancer cases and 275 matched controls. Each case was matched to a control by age, ethnicity, fasting status at the time of blood collection, time of day when blood was drawn, and month of blood draw. Multivariable logistic regression with adjustment for colorectal cancer risk factors was used to estimate the odds ratio (OR) and 95 % confidence interval (CI) for risk of colorectal cancer incidence and mortality by adiponectin quartiles based on the control distribution.

RESULTS

Median plasma adiponectin level was similar in cases versus controls (6.00 vs. 6.24 μg/mL). In multivariable-adjusted logistic regression models, high plasma adiponectin levels were not significantly associated with risk of colorectal cancer [quartile 4 (Q4) vs. quartile 1 (Q1): OR (95 % CI) 0.86 (0.48-1.56), p trend = 0.63].

CONCLUSIONS

These results suggest no appreciable association between plasma adiponectin and risk of colorectal cancer in women. Confirmation of these observations in larger studies is needed.

Circulating Vitamin D Levels and Risk of Colorectal Cancer in Women

Observational data on the association between circulating 25(OH)D and colorectal cancer risk are limited in women. To determine whether prediagnostic levels of 25(OH)D were associated with risk of incident colorectal cancer in the Women's Health Study (WHS), we conducted a nested case-control study using 274 colorectal cases and 274 controls. Each case was matched to a control by age, ethnicity, fasting status at the time of blood collection, time of day when blood was drawn, and month of blood draw. Conditional logistic regression was used to estimate the OR and 95% confidence interval (CI) for colorectal cancer by 25(OH)D quartiles. Mean plasma 25(OH)D was lower in cases versus controls (21.9 vs. 23.9 ng/mL, P = 0.01). In multivariable-adjusted logistic regression models, plasma 25(OH)D was significantly and inversely associated with odds of colorectal cancer (quartile 4 [Q4] vs. quartile 1 [Q1]: OR, 0.45; 95% CI, 0.25-0.81; Ptrend 0.02). In addition, we observed a somewhat lower risk of colorectal cancer-related mortality after adjustment for matching variables, randomization treatment and other risk factors (Q4:Q1 OR, 0.40; 95% CI, 0.17-0.97; Ptrend 0.05). In this cohort of healthy women, we found a significant inverse association between prediagnostic 25(OH)D levels and risk of incident colorectal cancer, and a borderline significant inverse association between prediagnostic 25(OH)D levels and colorectal cancer-related mortality. These results support a possible association between plasma 25(OH)D and risk of colorectal cancer in women.

Do moderate-intensity and vigorous-intensity physical activities reduce mortality rates to the same extent?

Background

Limited data exist directly comparing the relative benefits of moderate‐ and vigorous‐intensity activities with all‐cause and cardiovascular (CV) disease mortality rates when controlling for physical activity volume.

Methods and Results

We followed 7979 men (Harvard Alumni Health Study, 1988–2008) and 38 671 women (Women's Health Study, 1992–2012), assessing their physical activity and health habits through repeated questionnaires. Over a mean follow‐up of 17.3 years in men and 16.4 years in women, there were 3551 deaths (1077 from CV disease) among men and 3170 deaths (620 from CV disease) among women. Those who met or exceeded an equivalent of the federal guidelines recommendation of at least 150 minutes of moderate‐intensity activity, 75 minutes of vigorous‐intensity activity, or a combination of the 2 that expended similar energy experienced significantly lower all‐cause and CV disease–related mortality rates (men, 28% to 36% and 31% to 34%, respectively; women: 38% to 55% and 22% to 44%, respectively). When comparing different combinations of moderate‐ and vigorous‐intensity activity and all‐cause mortality rates, we observed sex‐related differences. Holding constant the volume of moderate‐ to vigorous‐intensity physical activity, men experienced a modest additional benefit when expending a greater proportion of moderate‐ to vigorous‐intensity physical activity in vigorous‐intensity activities (P_trend=0.04), but women did not (P_trend<0.001). Moderate‐ to vigorous‐intensity physical activity composition was not associated with further cardiovascular mortality rate reductions in either men or women.

Conclusions

The present data support guidelines recommending 150 minutes of moderate‐intensity activity per week, 75 minutes of vigorous‐intensity activity per week, or an equivalent combination for mortality benefits. Among men, but not women, additional modest reductions in all‐cause mortality rates are associated with a greater proportion of moderate‐ to vigorous‐intensity physical activity performed at a vigorous intensity.

Posttraumatic growth among men with histories of child sexual abuse

Despite an increased risk of long-term mental health problems, many survivors of child sexual abuse (CSA) experience positive changes in areas such as appreciation for life, personal strength, and interpersonal relationships. Drawing on life course theory, this study examined factors related to posttraumatic growth among a sample of men with CSA histories (N = 487). Using multiple linear regression (i.e., ordinary least squares), we found that men who had a better understanding of the sexual abuse experience, who ascribed to less traditional masculine norms, and who experienced a turning point reported greater growth. To promote growth, practitioners can help survivors understand the meaning and impact of the abuse on their lives and deconstruct rigid gender norms. More research on growth is needed with male survivors, especially on the nature of turning points in the recovery process.

Alternate-day, low-dose aspirin and cancer risk: long-term observational follow-up of a randomized trial

BACKGROUND

Recent evidence suggests that daily aspirin use decreases cancer risk, particularly for colorectal cancer, but evidence for alternate-day use is scant.

OBJECTIVE

To examine the association between long-term, alternate-day, low-dose aspirin and cancer in healthy women.

DESIGN

Observational follow-up of a randomized trial.

SETTING

Female health professionals.

PARTICIPANTS

39,876 women aged 45 years or older in the Women's Health Study (ClinicalTrials.gov: NCT00000479), 33 682 of whom continued observational follow-up.

INTERVENTION

100 mg of alternate-day aspirin or placebo through March 2004, with a median 10-year follow-up. Posttrial follow-up continued through March 2012.

MEASUREMENTS

Cancer incidence.

RESULTS

A total of 5071 cancer cases (including 2070 breast, 451 colorectal, and 431 lung cancer cases) and 1391 cancer deaths were confirmed. Over the entire follow-up, aspirin had no association with total (hazard ratio [HR], 0.97 [95% CI, 0.92 to 1.03]; P = 0.31), breast (HR, 0.98 [CI, 0.90 to 1.07]; P = 0.65), or lung (HR, 1.04 [CI, 0.86 to 1.26]; P = 0.67) cancer. Colorectal cancer was reduced in the aspirin group (HR, 0.80 [CI, 0.67 to 0.97]; P = 0.021), primarily for proximal colon cancer (HR, 0.73 [CI, 0.55 to 0.95]; P = 0.022). The difference emerged after 10 years, with a posttrial reduction of 42% (HR, 0.58 [CI, 0.42 to 0.80]; P < 0.001). There was no extended effect on cancer deaths or colorectal polyps. More gastrointestinal bleeding (HR, 1.14 [CI, 1.06 to 1.22]; P < 0.001) and peptic ulcers (HR, 1.17 [CI, 1.09 to 1.27]; P < 0.001) occurred in the aspirin group.

LIMITATIONS

Not all women received extended follow-up, and posttrial ascertainment bias cannot be ruled out. Gastrointestinal bleeding, peptic ulcers, and polyps were self-reported during extended follow-up.

CONCLUSION

Long-term use of alternate-day, low-dose aspirin may reduce risk for colorectal cancer in healthy women.

Vitamin E supplementation and the risk of heart failure in women

BACKGROUND

Oxidative stress may contribute to the development of heart failure (HF); however, an increased risk of HF has been observed with antioxidant therapy in secondary prevention trials. No large clinical trials have addressed the role of antioxidant therapy in the primary prevention of HF.

METHODS AND RESULTS

We examined the effect of vitamin E and HF risk in 39 815 initially healthy women, aged at least 45 years at baseline, who were enrolled in the Women's Health Study, a randomized, double-blind, placebo-controlled trial of vitamin E (600 IU every other day). Over a median follow-up of 10.2 years, there were 220 incident HF events. In proportional hazards models, adjusting for age and randomized aspirin and beta carotene treatment, vitamin E assignment did not significantly affect HF risk (hazards ratio [HR], 0.93; 95% CI, 0.71-1.21; P=0.59). These results did not change with multivariate adjustment for other risk factors, including interim myocardial infarction. In a prespecified subgroup analysis, vitamin E was inversely related to developing HF with normal ejection fraction (≥50%) with HR 0.59 (95% CI, 0.38-0.92; P=0.02), but there was no statistically significant effect on the risk of developing systolic HF (HR, 1.26; 95% CI, 0.84-1.89; P=0.26).

CONCLUSIONS

In this population of apparently healthy women, vitamin E did not affect the overall risk of HF. The possible benefit on diastolic HF requires confirmation in larger populations.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00000479.

Physical activity and the risk of incident atrial fibrillation in women

BACKGROUND

Physical activity (PA) is well known to reduce the risk of cardiovascular disease. We hypothesized that regular PA, possibly acting through reductions in blood pressure and body mass index (BMI), would reduce the risk of incident atrial fibrillation (AF) in women.

METHODS AND RESULTS

We prospectively followed 34 759 women who reported their leisure-time PA levels for the occurrence of AF. We estimated energy expenditure in metabolic equivalent (MET)-h/wk and validated self-reported AF with medical records. The mean (SD) age of the 34 759 participants was 54.6 (7.0) years, the mean BMI was 26.0 (5.0) kg/m(2), 26.5% had hypertension, and the median (IQR) PA was 8.4 (2.8, 20.4) MET-h/wk. After a median of 14.4 years of observation, 968 women had development of AF. In age-, cholesterol-, smoking-, alcohol-, diabetes-, and race-adjusted models, increasing quintiles of PA were associated with reduced risks of AF (hazard ratio for extreme quintiles, 0.82; 0.66 to 1.01; P trend=0.007 over quintiles). Although this association was not substantially different after adjusting for hypertension (0.87; 0.70 to 1.07; P trend 0.02), it was attenuated after adjustment for BMI (0.99; 0.80 to 1.23; P trend=0.22). Women who achieved the federal government's recommendation of 7.5 MET-h/wk of PA were at reduced risk of AF compared with those who did not (0.86; 0.75 to 0.98; P=0.03). This association was also attenuated by BMI (0.96; 0.84 to 1.10; P=0.57).

CONCLUSIONS

In middle-aged women, physical activity was associated with a modestly reduced risk of AF. However, this relationship was no longer significant after controlling for body mass index.

Amino-terminal pro-B-type natriuretic peptide and high-sensitivity C-reactive protein as predictors of sudden cardiac death among women

BACKGROUND

Plasma concentrations of N-terminal pro-B-type natriuretic peptide (NT-proBNP) have been found to predict risk of sudden cardiac death (SCD) in patients with known cardiac disease, and C-reactive protein levels have been found to predict risk among apparently healthy men. However, there are no data on SCD risk prediction for either of these markers in a population of women unselected on the basis of cardiovascular disease.

METHODS AND RESULTS

In a prospective, nested, case-control analysis within the 121,700-participant Nurses' Health Study, 99 cases of definite or probable SCD were identified and matched to 294 controls. In multivariable models that adjusted for coronary heart disease risk factors, glomerular filtration rate, and other biomarkers, the trend across quartiles approached significance for NT-proBNP (rate ratio=2.37 for comparison of the highest and lowest quartile; P for trend=0.05) but not for high-sensitivity C-reactive protein (P for trend=0.60). When examined continuously, both NT-proBNP and high-sensitivity C-reactive protein were significantly associated with SCD risk in age- and fasting-adjusted models (P for linear trend=0.04 and 0.03). Adjustment for coronary heart disease risk factors and other biomarkers strengthened the relationship with NT-proBNP and SCD (relative risk for 1-SD increment=1.49; 95% confidence interval, 1.09 to 2.05; P=0.01) but eliminated the relationship with high-sensitivity C-reactive protein (P=0.34). Women with NT-proBNP levels above the prespecified cut point of 389 pg/mL were at a markedly increased risk of SCD in both models (rate ratio=5.68; 95% confidence interval, 1.78 to 18.2; P=0.003).

CONCLUSIONS

In this population of women, baseline levels of NT-proBNP were associated with subsequent risk of SCD. If this association is confirmed in larger prospectively studied populations, these findings might provide another useful marker contributing to efforts to screen and prevent SCD among women.

Alcohol consumption and risk of incident atrial fibrillation in women

CONTEXT

Previous studies suggest that consuming moderate to high amounts of alcohol on a regular basis might increase the risk of developing atrial fibrillation in men but not in women. However, these studies were not powered to investigate the association of alcohol consumption and atrial fibrillation among women.

OBJECTIVE

To prospectively assess the association between regular alcohol consumption and incident atrial fibrillation among women.

DESIGN, SETTING, AND PARTICIPANTS

Participants were 34 715 initially healthy women participating in the Women's Health Study, a completed randomized controlled trial conducted in the United States. Participants were older than 45 years and free of atrial fibrillation at baseline and underwent prospective follow-up from 1993 to October 31, 2006. Alcohol consumption was assessed via questionnaires at baseline and at 48 months of follow-up and was grouped into 4 categories (0, > 0 and < 1, > or = 1 and < 2, and > or = 2 drinks per day). Atrial fibrillation was self-reported on the yearly questionnaires and subsequently confirmed by electrocardiogram and medical record review.

MAIN OUTCOME MEASURE

Time to first episode of atrial fibrillation.

RESULTS

Over a median follow-up of 12.4 years, 653 cases of incident atrial fibrillation were confirmed. Age-adjusted incidences among women consuming 0 (n = 15,370), more than 0 and less than 1 (n = 15,758), 1 or more and less than 2 (n = 2228), and 2 or more (n = 1359) drinks per day were 1.59, 1.55, 1.27, and 2.25 events/1000 person-years of follow-up. Thus, compared with nondrinking women, women consuming 2 or more drinks per day had an absolute risk increase of 0.66 events/1000 person-years. The corresponding multivariate-adjusted hazard ratios (HRs) for incident atrial fibrillation were 1, 1.05 (95% CI, 0.88-1.25), 0.84 (95% CI, 0.58-1.22), and 1.60 (95% CI, 1.13-2.25), respectively. The increased hazard in the small group of women consuming 2 or more drinks per day persisted when alcohol intake was updated at 48 months (HR, 1.49; 95% CI, 1.05-2.11) or when women were censored at their first cardiovascular event (HR, 1.68; 95% CI, 1.18-2.39).

CONCLUSIONS

Among healthy middle-aged women, consumption of up to 2 alcoholic beverages per day was not associated with an increased risk of incident atrial fibrillation. Heavier consumption of 2 or more drinks per day, however, was associated with a small but statistically significant increased risk of atrial fibrillation.

Analysis of sister chromatid exchange, micronucleus and chromosomal aberration frequencies in rodents exposed to mosquito coil smoke by inhalation route

Mosquito coil smoke emitting from a mosquito repellent, was tested for its mutagenic effect in bone marrow cells from mouse and rat after 4 h acute inhalation exposure. Coil smoke with suspended particulate concentrations of 99-129 mg/m3, significantly elevated the frequencies of sister chromatid exchanges in bone marrow cells and micronuclei in polychromatic erythrocytes. Analysis of chromosomal aberrations in metaphases also revealed a significantly higher incidence of chromosomal aberration frequency in exposed rats and mice.

Effect of thiamine hydrochloride on the blood level of 2-formyl 1-methyl pyridinium oxime chloride (2-PAM.C1) in rats

The biological half-life of 2-PAM.C1 was found to increase in female rats pretreated with thiamine hydrochloride (10 mg/kg i.m.). No such effect was observed in the male rats.