Cumulative socioeconomic status and incident type 2 diabetes among African American adults from the Jackson heart study

Background

The cumulative socioeconomic status (SES) model posits that childhood and adult experiences accumulate to influence disease risk. While individual SES indicators such as education and income are independently associated with incident type 2 diabetes (T2D), the association of cumulative SES and incident T2D is unclear, especially in African American adults.

Methods

We utilized cohort data of African American participants (n = 3681, mean age 52.6 years) enrolled in the Jackson Heart Study from 2000 to 2013 free of T2D or cardiovascular disease at baseline (2000-2004). Cumulative SES scores at baseline were derived using six SES indicators (education, wealth, income, occupation, employment status, and mother's education) categorized as low, middle, and high. Incident T2D was defined at exam 2 (2005-2008) or exam 3 (2009-2013) based on fasting glucose ≥126 mg/dL, HbA1c ≥ 6.5, reported diabetic medication use, or self-reported physician diagnosis. Proportional hazards regression, allowing for interval censoring, was used to estimate the association between cumulative SES and incident T2D (hazard ratio(HR), 95% confidence interval (CI)) after adjustment for covariates. Sex and age differences were tested using interaction terms.

Results

There were 544 incident T2D cases. The association between low (versus high) cumulative SES and incident T2D was not significant (HR 1.04 [95% CI 0.85, 1.28]) and did not differ by sex (p value for interaction>0.05). However, there were differences by (age p value for interaction = 0.0052 for middle-aged adults and 0.0186 for older adults). Low (versus high) cumulative SES was associated a greater hazard of incident T2D among those 20-46 years (HR 1.12 [95% CI 1.03, 1.21]), 47-59 years (HR 1.25 [95% CI 1.06, 1.47]) and those 60-93 years (HR 1.39 [95% CI 1.09, 1.78]) after adjustment for sex and family history of diabetes. Associations attenuated after adding behavioral and lifestyle risk factors.

Conclusion

The association of low cumulative SES and incident T2D differed by age, which may suggest interventionist should consider impacts of SES on T2D by age.

Lung function impairment and risk of incident heart failure: the NHLBI Pooled Cohorts Study

AIMS

The aim is to evaluate associations of lung function impairment with risk of incident heart failure (HF).

METHODS AND RESULTS

Data were pooled across eight US population-based cohorts that enrolled participants from 1987 to 2004. Participants with self-reported baseline cardiovascular disease were excluded. Spirometry was used to define obstructive [forced expiratory volume in 1 s/forced vital capacity (FEV1/FVC) <0.70] or restrictive (FEV1/FVC ≥0.70, FVC <80%) lung physiology. The incident HF was defined as hospitalization or death caused by HF. In a sub-set, HF events were sub-classified as HF with reduced ejection fraction (HFrEF; EF <50%) or preserved EF (HFpEF; EF ≥50%). The Fine-Gray proportional sub-distribution hazards models were adjusted for sociodemographic factors, smoking, and cardiovascular risk factors. In models of incident HF sub-types, HFrEF, HFpEF, and non-HF mortality were treated as competing risks. Among 31 677 adults, there were 3344 incident HF events over a median follow-up of 21.0 years. Of 2066 classifiable HF events, 1030 were classified as HFrEF and 1036 as HFpEF. Obstructive [adjusted hazard ratio (HR) 1.17, 95% confidence interval (CI) 1.07-1.27] and restrictive physiology (adjusted HR 1.43, 95% CI 1.27-1.62) were associated with incident HF. Obstructive and restrictive ventilatory defects were associated with HFpEF but not HFrEF. The magnitude of the association between restrictive physiology and HFpEF was similar to associations with hypertension, diabetes, and smoking.

CONCLUSION

Lung function impairment was associated with increased risk of incident HF, and particularly incident HFpEF, independent of and to a similar extent as major known cardiovascular risk factors.

Low Liver Enzymes and Risk of Dementia: The Atherosclerosis Risk in Communities (ARIC) Study

BACKGROUND

Low levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in the low physiologic range, surrogate markers for reduced liver metabolic function, are associated with cerebral hypometabolism, impairment in neurotransmitter production and synaptic maintenance, and a higher prevalence of dementia. It is unknown whether a prospective association exists between low liver enzyme levels and incident dementia.

OBJECTIVE

To determine whether low levels of ALT and AST are associated with higher risk of incident dementia.

METHODS

Plasma ALT and AST were measured on 10,100 study participants (mean age 63.2 years, 55% female, 22% black) in 1996-1998. Dementia was ascertained from comprehensive neuropsychological assessments, annual contact, and medical record surveillance. Cox proportional hazards regression was used to estimate the association.

RESULTS

During a median follow-up of 18.3 years (maximum 21.9 years), 1,857 individuals developed dementia. Adjusted for demographic factors, incidence rates of dementia were higher at the lower levels of ALT and AST. Compared to the second quintile, ALT values <10th percentile were associated with a higher risk of dementia (hazard ratio [HR] 1.34, 95% CI 1.08-1.65). The corresponding HR was 1.22 (0.99-1.51) for AST.

CONCLUSION

Plasma aminotransferases <10th percentile of the physiologic range at mid-life, particularly ALT, were associated with greater long-term risk of dementia, advocating for attention to the putative role of hepatic function in the pathogenesis of dementia.

A Dyadic Growth Modeling Approach for Examining Associations Between Weight Gain and Lung Function Decline

The relationship between body weight and lung function is complex. Using a dyadic multilevel linear modeling approach, treating body mass index (BMI; weight (kg)/height (m)2) and lung function as paired, within-person outcomes, we tested the hypothesis that persons with more rapid increase in BMI exhibit more rapid decline in lung function, as measured by forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and their ratio (FEV1:FVC). Models included random intercepts and slopes and adjusted for sociodemographic and smoking-related factors. A sample of 9,115 adults with paired measurements of BMI and lung function taken at ≥3 visits were selected from a pooled set of 5 US population-based cohort studies (1983-2018; mean age at baseline = 46 years; median follow-up, 19 years). At age 46 years, average annual rates of change in BMI, FEV1, FVC, and FEV1:FVC ratio were 0.22 kg/m2/year, -25.50 mL/year, -21.99 mL/year, and -0.24%/year, respectively. Persons with steeper BMI increases had faster declines in FEV1 (r = -0.16) and FVC (r = -0.26) and slower declines in FEV1:FVC ratio (r = 0.11) (all P values < 0.0001). Results were similar in subgroup analyses. Residual correlations were negative (P < 0.0001), suggesting additional interdependence between BMI and lung function. Results show that greater rates of weight gain are associated with greater rates of lung function loss.

Nine-Year Ethanol Intake Trajectories and Their Association With 15-Year Cognitive Decline Among Black and White Adults

Faster rates of age-related cognitive decline might result in early onset of cognitive impairment and dementia. The relationship between ethanol intake and cognitive decline, although studied extensively, remains poorly understood. Previous studies used single measurements of ethanol, and few were conducted in diverse populations. We assessed the association of 9-year trajectories of ethanol intake (1987-1998) with 15-year rate of decline in cognitive performance from mid- to late life (1996-2013) among 2,169 Black and 8,707 White participants of the US Atherosclerosis Risk in Communities study using multivariable linear regression models. We hypothesized that stable, low to moderate drinking would be associated with lesser 15-year cognitive decline, and stable, heavy drinking with greater 15-year cognitive decline. Stable, low to moderate drinking (for Blacks, adjusted mean difference (MD) = 0.03 (95% confidence interval (CI): -0.13, 0.19); for Whites, adjusted MD = 0.02 (95% CI: -0.05, 0.08)) and stable, heavy drinking (for Blacks, adjusted MD = 0.08 (95% CI: -0.34, 0.50); for Whites, adjusted MD = -0.03 (95% CI: -0.18, 0.11)) in midlife compared with stable never-drinking were not associated with 15-year decline in general cognitive function from mid- to late life. No association was observed for the stable former and "mostly" drinking trajectories with 15-year cognitive decline. Stable low, low to moderate, and stable heavy drinking in midlife are not associated with lesser and greater cognitive decline, respectively, from mid- to late life among Black and White adults.

Insulin resistance and reduced cardiac autonomic function in older adults: the Atherosclerosis Risk in Communities study

Background

Prior studies have shown insulin resistance is associated with reduced cardiac autonomic function measured at rest, but few studies have determined whether insulin resistance is associated with reduced cardiac autonomic function measured during daily activities.

Methods

We examined older adults without diabetes with 48-h ambulatory electrocardiography (n = 759) in an ancillary study of the Atherosclerosis Risk in Communities Study. Insulin resistance, the exposure, was defined by quartiles for three indexes: 1) the homeostatic model assessment of insulin resistance (HOMA-IR), 2) the triglyceride and glucose index (TyG), and 3) the triglyceride to high-density lipoprotein cholesterol ratio (TG/HDL-C). Low heart rate variability, the outcome, was defined by <25th percentile for four measures: 1) standard deviation of normal-to-normal R-R intervals (SDNN), a measure of total variability; 2) root mean square of successive differences in normal-to-normal R-R intervals (RMSSD), a measure of vagal activity; 3) low frequency spectral component (LF), a measure of sympathetic and vagal activity; and 4) high frequency spectral component (HF), a measure of vagal activity. Logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals weighted for sampling/non-response, adjusted for age at ancillary visit, sex, and race/study-site. Insulin resistance quartiles 4, 3, and 2 were compared to quartile 1; high indexes refer to quartile 4 versus quartile 1.

Results

The average age was 78 years, 66% (n = 497) were women, and 58% (n = 438) were African American. Estimates of association were not robust at all levels of HOMA-IR, TyG, and TG/HDL-C, but suggest that high indexes were associated consistently with indicators of vagal activity. High HOMA-IR, high TyG, and high TG/HDL-C were consistently associated with low RMSSD (OR: 1.68 (1.00, 2.81), OR: 2.03 (1.21, 3.39), and OR: 1.73 (1.01, 2.91), respectively). High HOMA-IR, high TyG, and high TG/HDL-C were consistently associated with low HF (OR: 1.90 (1.14, 3.18), OR: 1.98 (1.21, 3.25), and OR: 1.76 (1.07, 2.90), respectively).

Conclusions

In older adults without diabetes, insulin resistance was associated with reduced cardiac autonomic function – specifically and consistently for indicators of vagal activity – measured during daily activities. Primary prevention of insulin resistance may reduce the related risk of cardiac autonomic dysfunction.

Goal-Striving Stress and Incident Cardiovascular Disease in Blacks: The Jackson Heart Study

Background Goal-striving stress (GSS), the stress from striving for goals, is associated with poor health. Less is known about its association with cardiovascular disease (CVD). Methods and Results We used data from the JHS (Jackson Heart Study), a study of CVD among blacks (21-95 years old) from 2000 to 2015. Participants free of CVD at baseline (2000-2004) were included in this analysis (n=4648). GSS was examined in categories (low, moderate, high) and in SD units. Incident CVD was defined as fatal or nonfatal stroke, coronary heart disease (CHD), and/or heart failure. We used Cox proportional hazards regression to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) of incident CVD by levels of GSS, adjusting for demographics, socioeconomic status, health behaviors, risk factors, and perceived stress. The distribution of GSS categories was as follows: 40.77% low, 33.97% moderate, and 25.26% high. Over an average of 12 years, there were 140 incident stroke events, 164 CHD events, and 194 heart failure events. After full adjustment, high (versus low) GSS was associated with a lower risk of stroke (HR, 0.38; 95% CI, 0.17-0.83) and a higher risk of CHD (HR, 1.91; 95% CI, 1.10-3.33) among women. A 1-standard deviation unit increase in GSS was associated with a 31% increased risk of CHD (HR, 1.31; 95% CI, 1.10-1.56) among women. Conclusions Higher GSS may be a risk factor for developing CHD among women; however, it appears to be protective of stroke among women. These analyses should be replicated in other samples of black individuals.

Association of insulin resistance, from mid-life to late-life, with aortic stiffness in late-life: the Atherosclerosis Risk in Communities Study

Background

Insulin resistance may contribute to aortic stiffening that leads to end-organ damage. We examined the cross-sectional association and prospective association of insulin resistance and aortic stiffness in older adults without diabetes.

Methods

We analyzed 2571 men and women at Visit 5 (in 2011–2013), and 2350 men and women at repeat examinations from baseline at Visit 1 (in 1987–1989) to Visit 5 (in 2011–2013). Linear regression was used to estimate the difference in aortic stiffness per standard unit of HOMA-IR, TG/HDL-C, and TyG at Visit 5. Linear mixed effects were used to assess if high, as opposed to non-high, aortic stiffness (> 75th percentile) was preceded by a faster annual rate of change in log-HOMA-IR, log-TG/HDL-C, and log-TyG from Visit 1 to Visit 5.

Results

The mean age of participants was 75 years, 37% (n = 957) were men, and 17% (n = 433) were African American. At Visit 5, higher HOMA-IR, higher TG/HDL-C, and higher TyG were associated with higher aortic stiffness (16 cm/s per SD (95% CI 6, 27), 29 cm/s per SD (95% CI 18, 40), and 32 cm/s per SD (95% CI 22, 42), respectively). From Visit 1 to Visit 5, high aortic stiffness, compared to non-high aortic stiffness, was not preceded by a faster annual rate of change in log-HOMA-IR from baseline to 9 years (0.030 (95% CI 0.024, 0.035) vs. 0.025 (95% CI 0.021, 0.028); p = 0.15) or 9 years onward (0.011 (95% CI 0.007, 0.015) vs. 0.011 (95% CI 0.009, 0.013); p = 0.31); in log-TG/HDL-C from baseline to 9 years (0.019 (95% CI 0.015, 0.024) vs. 0.024 (95% CI 0.022, 0.026); p = 0.06) or 9 years onward (− 0.007 (95% CI − 0.010, − 0.005) vs. − 0.009 (95% CI − 0.010, − 0.007); p = 0.08); or in log-TyG from baseline to 9 years (0.002 (95% CI 0.002, 0.003) vs. 0.003 (95% CI 0.003, 0.003); p = 0.03) or 9 years onward (0 (95% CI 0, 0) vs. 0 (95% CI 0, 0); p = 0.08).

Conclusions

Among older adults without diabetes, insulin resistance was associated with aortic stiffness, but the putative role of insulin resistance in aortic stiffness over the life course requires further study.

Association of Undifferentiated Dyspnea in Late Life With Cardiovascular and Noncardiovascular Dysfunction: A Cross-sectional Analysis From the ARIC Study

Importance

Undifferentiated dyspnea is common in late life, but the relative contribution of subclinical cardiac dysfunction is unknown. Impairments in cardiac structure and function may be characteristics of undifferentiated dyspnea in elderly people, providing potential insights into occult heart failure (HF).

Objective

To quantify the association of undifferentiated dyspnea with cardiac dysfunction after accounting for other potential contributors.

Design, Setting, and Participants

This cross-sectional study used data from Atherosclerosis Risk in Communities study participants 65 years and older who attended the fifth study visit (from 2011 to 2013) and had not been diagnosed with HF, chronic obstructive pulmonary disease, morbid obesity, or severe kidney disease. Analyses were conducted from October 2017 to June 2018.

Exposures

Dyspnea measured using the modified Medical Research Council scale, with a score less than 2 classified as none to mild and a score of 2 or more classified as moderate to severe.

Main Outcomes and Measures

Using multivariable logistic regression, the association of undifferentiated dyspnea was defined using cardiac structure, systolic and diastolic function, pulmonary pressure (echocardiography), pulmonary function (spirometry), glomerular filtration rate, hemoglobin, body mass index, depression, and physical performance. The population-attributable risk was calculated for each dysfunction metric.

Results

Among 4342 participants (mean [SD] age, 75.9 [5.0] years; 2533 [58.3%] women), 1173 (27.0%) had undifferentiated dyspnea. Moderate to severe dyspnea was present in 574 participants (13.2%) and was associated with left ventricular (LV) hypertrophy (odds ratio [OR], 1.53; 95% CI, 1.25-1.87; P < .001) and LV diastolic (OR, 1.46; 95% CI, 1.20-1.78; P < .001) and systolic (OR, 1.28; 95% CI, 1.05-1.56; P = .02) dysfunction. Moderate to severe dyspnea was also associated with obstructive (OR, 1.59; 95% CI, 1.28-1.99; P < .001) and restrictive (OR, 2.56; 95% CI, 1.99-3.27; P < .001) findings on spirometry, renal impairment (OR, 1.32; 95% CI, 1.08-1.61; P = .01), anemia (OR, 1.72; 95% CI, 1.39-2.12; P < .001), lower (OR, 2.77; 95% CI, 2.18-3.51; P < .001) and upper (OR, 1.82; 95% CI, 1.49-2.23; P < .001) extremity weakness, depression (OR, 3.01; 95% CI, 2.24-4.25; P < .001), and obesity (OR, 2.35; 95% CI, 1.95-2.83; P < .001). After accounting for these, moderate to severe dyspnea was associated with LV hypertrophy (OR, 1.30; 95% CI, 1.01-1.67; P = .04) and was not associated with systolic or diastolic function. In contrast, in the fully adjusted model, other organ system measures were associated with dyspnea, except for glomerular filtration rate and grip strength. The population-attributable risk of dyspnea associated with obesity alone was 22.6% compared with 5.8% for LV hypertrophy.

Conclusions and Relevance

Undifferentiated dyspnea is multifactorial in older adults, and this study showed an association with obesity. When accounting for other relevant organ systems, cardiovascular function poorly discriminated those with vs those without dyspnea. Therefore, dyspnea should not be assumed to represent occult HF in this population.

Relationship between QRS duration and incident atrial fibrillation

BACKGROUND

QRS duration (QRSd), a measure of ventricular conduction, has been associated with adverse cardiovascular outcomes, but its relationship with incident atrial fibrillation (AF) is poorly understood.

METHODS AND RESULTS

This study included 15,314 participants from the Atherosclerosis Risk in Communities (ARIC) study who were free of AF at baseline. QRSd was automatically measured from resting 12-lead electrocardiograms (ECGs) at baseline. Incident AF cases were systematically ascertained using ECGs, hospital discharge diagnoses and death certificates. Multivariable adjusted Cox regression analyses were performed to investigate the relationship between QRSd and incident AF. Mean age of our population was 54 ± 6 years (55% females). During a median follow-up of 21.2 years, 2041 confirmed incident AF cases occurred. In multivariable adjusted Cox models, a 1-SD increase in QRSd was associated with a hazard ratio (HR) (95% CI) for AF of 1.05 (1.01; 1.10), p = 0.01. This relationship was significant among women (HR per 1-SD increase in QRSd (95% CI) 1.13 (1.06; 1.20), p < 0.001), but not among men (1.00 (0.95; 1.06), p = 0.97) (p for interaction 0.005). Compared to individuals with a QRSd <100 ms, the HRs for incident AF in individuals with a QRSd of 100-119 and ≥120 ms were 1.13 (1.02; 1.26) and 1.35 (1.08; 1.68), respectively (p for trend 0.002). Again, this relationship was significant among women (p for trend <0.001) but not among men (p for trend 0.23).

CONCLUSION

In this large population-based study, QRSd was an independent predictor of incident AF among women, but not in men. Further studies are needed to better understand the underlying mechanisms.

Short-Term Repeatability of Insulin Resistance Indexes in Older Adults: The Atherosclerosis Risk in Communities Study

CONTEXT

The homeostatic model assessment of insulin resistance (HOMA-IR) and triglyceride (TG)/high-density lipoprotein cholesterol (HDL-C) ratio (TG/HDL-C) are insulin resistance indexes routinely used in clinical and population-based studies; however, their short-term repeatability is not well characterized.

OBJECTIVE

To quantify the short-term repeatability of insulin resistance indexes and their analytes, consisting of fasting glucose and insulin for HOMA-IR and TG and HDL-C for TG/HDL-C.

DESIGN

Prospective cohort study.

PARTICIPANTS

A total of 102 adults 68 to 88 years old without diabetes attended an initial examination and repeated examination (mean, 46 days; range, 28 to 102 days). Blood samples were collected, processed, shipped, and assayed following a standardized protocol.

MAIN OUTCOME MEASURES

Repeatability was quantified using the intraclass correlation coefficient (ICC) and within-person coefficient of variation (CV). Minimum detectable change (MDC95) and minimum detectable difference with 95% confidence (MDD95) were quantified.

RESULTS

For HOMA-IR, insulin, and fasting glucose, the ICCs were 0.70, 0.68, and 0.70, respectively; their respective within-person CVs were 30.4%, 28.8%, and 5.6%. For TG/HDL-C, TG, and HDL-C, the ICCs were 0.80, 0.68, and 0.91, respectively; their respective within-person CVs were 23.0%, 20.6%, and 8.2%. The MDC95 was 2.3 for HOMA-IR and 1.4 for TG/HDL-C. The MDD95 for a sample of n = 100 was 0.8 for HOMA-IR and 0.6 for TG/HDL-C.

CONCLUSIONS

Short-term repeatability was fair to good for HOMA-IR and excellent for TG/HDL-C according to suggested benchmarks, reflecting the short-term variability of their analytes. These measurement properties can inform the use of these indexes in clinical and population-based studies.

Incidence of Heart Failure Observed in Emergency Departments, Ambulatory Clinics, and Hospitals

Reports on the burden of heart failure (HF) have largely omitted HF diagnosed in outpatient settings. We quantified annual incidence rates ([IR] per 1,000 person years) of HF identified in ambulatory clinics, emergency departments (EDs), and during hospital stays in a national probability sample of Medicare beneficiaries from 2008 to 2014, by age and race/ethnicity. A 20% random sample of Medicare beneficiaries ages ≥65 years with continuous Medicare Parts A, B, and D coverage was used to estimate annual IRs of HF identified using International Classification of Diseases, Ninth Revision, Clinical Modification codes. Of the 681,487 beneficiaries with incident HF from 2008 to 2014, 283,451 (41%) presented in ambulatory clinics, 76,919 (11%) in EDs, and 321,117 (47%) in hospitals. Overall, incidence of HF in ambulatory clinics decreased from 2008 (IR 22.2, 95% confidence interval [CI] 22.0, 22.4) to 2014 (IR 15.0, 95% CI 14.8, 15.1). Similarly, incidence of HF-related ED visits without an admission to the hospital decreased somewhat from 2008 (IR 5.5, 95% CI 5.4, 5.6) to 2012 (IR 4.2, 95% CI 4.1, 4.3) and stabilized from 2013 to 2014. Similar to previous reports, HF hospitalizations, both International Classification of Diseases, Ninth Revision, Clinical Modification code 428.x in the primary and any position, decreased over the study period. More than half of all new cases of HF in Medicare beneficiaries presented in an ambulatory clinic or ED. The overall incidence of HF decreased from 2008 to 2014, regardless of health-care setting. In conclusion, consideration of outpatient HF is warranted to better understand the burden of HF and its temporal trends.

Frequency of Care and Mortality Following an Incident Diagnosis of Peripheral Artery Disease in the Inpatient or Outpatient Setting: The ARIC (Atherosclerosis Risk in Communities) Study

Background

Available health services data for individuals with peripheral artery disease (PAD) are often from studies of those eligible for or undergoing intervention. Knowledge of the frequency of care and mortality following an initial PAD diagnosis by setting (outpatient versus inpatient) is limited and represents an opportunity to provide new benchmark information.

Methods and Results

The purpose of this study was to characterize the frequency of care and mortality following an incident PAD diagnosis in the outpatient or inpatient setting using data from the ARIC (Atherosclerosis Risk in Communities) study cohort linked with Centers for Medicare and Medicaid Services fee‐for‐service claims data (2002–2012). Direct standardization was used to estimate age‐standardized rates of encounters and mortality. PAD was defined by billing code in any claim position. We observed 1086 incident PAD cases (873 outpatient, 213 inpatient). At 1 year after diagnosis, participants diagnosed in the outpatient setting had 2.15 (95% confidence interval [CI], 2.10–2.21) PAD‐related outpatient encounters per person‐year, and 6.4% (95% CI, 4.8–8.1) had a PAD‐related hospitalization. Conversely, participants diagnosed in the inpatient setting had 1.02 (95% CI, 0.94–1.10) PAD‐related outpatient encounters per person‐year, and 14.2% (95% CI, 9.3–18.7) had a PAD‐related rehospitalization. One‐year mortality was 7.1% (95% CI, 5.4–8.7) and 16.0% (95% CI, 11.0–21.1) among those diagnosed in outpatient and inpatient settings, respectively.

Conclusions

This study provides important data estimating frequency of care and mortality by the setting of initial PAD diagnosis. Individuals with PAD are frequent users of health care, and those diagnosed in the inpatient setting have high rates of rehospitalization and mortality.

Accuracy of Self-Reported Heart Failure. The Atherosclerosis Risk in Communities (ARIC) Study

OBJECTIVE

The aim of this work was to estimate agreement of self-reported heart failure (HF) with physician-diagnosed HF and compare the prevalence of HF according to method of ascertainment.

METHODS AND RESULTS

ARIC cohort members (60-83 years of age) were asked annually whether a physician indicated that they have HF. For those self-reporting HF, physicians were asked to confirm their patients' HF status. Physician-diagnosed HF included surveillance of hospitalized HF and hospitalized and outpatient HF identified in administrative claims databases. We estimated sensitivity, specificity, positive predicted value, kappa, prevalence and bias-adjusted kappa (PABAK), and prevalence. Compared with physician-diagnosed HF, sensitivity of self-report was low (28%-38%) and specificity was high (96%-97%). Agreement was poor (kappa 0.32-0.39) and increased when adjusted for prevalence and bias (PABAK 0.73-0.83). Prevalence of HF measured by self-report (9.0%), ARIC-classified hospitalizations (11.2%), and administrative hospitalization claims (12.7%) were similar. When outpatient HF claims were included, prevalence of HF increased to 18.6%.

CONCLUSIONS

For accurate estimates HF burden, self-reports of HF are best confirmed by means of appropriate diagnostic tests or medical records. Our results highlight the need for improved awareness and understanding of HF by patients, because accurate patient awareness of the diagnosis may enhance management of this common condition.

Peripheral Artery Disease Prevalence and Incidence Estimated From Both Outpatient and Inpatient Settings Among Medicare Fee-for-Service Beneficiaries in the Atherosclerosis Risk in Communities (ARIC) Study

Background

Outpatient ascertainment of peripheral artery disease (PAD) is rarely considered in the measurement of PAD clinical burden; therefore, the clinical burden of PAD likely has been underestimated while contributing to a decreased awareness of PAD in comparison to other circulatory system disorders.

Methods and Results

The purpose of this study was to estimate the age‐standardized annual period prevalence and incidence of PAD in the outpatient and inpatient settings using data from the Atherosclerosis Risk in Communities (ARIC) study linked with Centers for Medicare and Medicaid Services claims. The majority (>70%) of all PAD encounters occurred in the outpatient setting. The weighted mean age‐standardized prevalence and incidence of outpatient PAD was 11.8% (95% CI 11.5–12.1) and 22.4 per 1000 person‐years (95% CI 20.8–24.0), respectively. Black patients had higher weighted mean age‐standardized prevalence (15.6%; 95% CI 14.6–16.4) compared with white patients (11.4%; 95% CI 11.1–11.7). Black women had the highest weighted mean age‐standardized prevalence (16.9%; 95% CI 16.0–17.8). Black patients also had a higher incidence rate of PAD (31.3 per 1000 person‐years; 95% CI 27.3–35.4) compared with white patients (25.4 per 1000 person‐years; 95% CI 23.5–27.3). PAD prevalence and incidence did not differ by sex alone.

Conclusions

This study provides comprehensive estimates of PAD in the inpatient and outpatient settings where the majority of PAD burden was found. PAD is an important circulatory system disorder similar in prevalence to stroke and coronary heart disease.

Electrocardiographic intervals associated with incident atrial fibrillation: Dissecting the QT interval

BACKGROUND

Prolongation of the QT interval has been associated with an increased risk of developing atrial fibrillation (AF), but the responsible mechanism remains unknown.

OBJECTIVES

The aims of this study were to subdivide the QT interval into its components and identify the resultant electrocardiographic interval(s) responsible for the association with AF.

METHODS

Predefined QT-interval components were assessed for association with incident AF in the Atherosclerosis Risk in Communities study using Cox proportional hazards models. Hazard ratios (HRs) were calculated per 1-SD increase in each component. Among QT-interval components exhibiting significant associations, additional analyses evaluating long extremes, defined as greater than the 95^th percentile, were performed.

RESULTS

Of the 14,625 individuals, 1505 (10.3%) were diagnosed with incident AF during a mean follow-up period of 17.6 years. After multivariable adjustment, QT-interval components involved in repolarization, but not depolarization, exhibited significant associations with incident AF, including a longer ST segment (HR 1.27; 95% confidence interval [CI] 1.14-1.41; P < .001) and a prolonged T-wave onset to T-wave peak (T-onset to T-peak) (HR 1.13; 95% CI 1.07-1.20; P < .001). Marked prolongation of the ST segment (HR 1.31; 95% CI 1.04-1.64; P = .022) and T-onset to T-peak (HR 1.36; 95% CI 1.09-1.69; P = .006) was also associated with an increased risk of incident AF.

CONCLUSION

The association between a prolonged QT interval and incident AF is primarily explained by components involved in ventricular repolarization: prolongation of the ST segment and T-onset to T-peak. These observations suggest that prolongation of phases 2 and 3 of the cardiac action potential drives the association between the QT interval and AF risk.

BNP and obesity in acute decompensated heart failure with preserved vs. reduced ejection fraction: The Atherosclerosis Risk in Communities Surveillance Study

BACKGROUND

Levels of B-type natriuretic peptide (BNP), a prognostic marker in patients with heart failure (HF), are lower among HF patients with obesity or preserved Left Ventricular Ejection Fraction (LVEF). We examined the distribution and prognostic value of BNP across BMI categories in acute decompensated heart failure (ADHF) patients with preserved vs. reduced LVEF.

METHODS

We analyzed data from the Atherosclerosis Risk in Communities (ARIC) HF surveillance study which sampled and adjudicated ADHF hospitalizations in patients aged ≥55years from 4 US communities (2005-2009). We examined 5 BMI categories: underweight (<18.5kg/m²), normal weight (18.5-<25), overweight (25-<30), obese (30-<40) and morbidly obese (≥40) in HF with preserved LVEF (HFpEF) and reduced LVEF (HFrEF). The outcome was 1-year mortality from admission. We used ANCOVA to model log BNP and logistic regression for 1-year mortality, both adjusted for demographics and clinical characteristics.

RESULTS

The cohort included 9820 weighted ADHF hospitalizations (58% HFrEF; 42% HFpEF). BNP levels were lower in HFpEF compared to HFrEF (p<0.001) and decreased as BMI increased within the LVEF groups (p<0.001). After adjustment for covariates, log10 BNP independently predicted 1-year mortality (adjusted OR 1.62 (95% CI 1.17-2.24)) with no significant interaction by BMI or LVEF groups.

CONCLUSIONS

BNP levels correlated inversely with BMI, and were higher in HFrEF compared to HFpEF. Obese patients with HFpEF and ADHF had a significant proportion with BNP levels below clinically accepted thresholds. Nevertheless, BNP was a predictor of mortality in ADHF across groups of BMI in HFpEF and HFrEF.

Prognostic Importance of Dyspnea for Cardiovascular Outcomes and Mortality in Persons without Prevalent Cardiopulmonary Disease: The Atherosclerosis Risk in Communities Study

Background

The relationship between dyspnea and incident heart failure (HF) and myocardial infarction (MI) among patients without previously diagnosed cardiopulmonary disease is unclear. We studied the prognostic relevance of self-reported dyspnea for cardiovascular outcomes and all-cause mortality in persons without previously diagnosed cardiopulmonary disease.

Methods and Results

We studied 10 881 community-dwelling participants (mean age 57±6, 56% women, 25% black) who were free of prevalent cardiopulmonary disease from Atherosclerosis Risk in Communities Study. Dyspnea status at study entry using the modified Medical Research Council (mMRC) scale. The primary outcomes were time to HF, MI or all-cause death. Dyspnea prevalence was 22%, and was mild (mMRC grade 1 or 2) in 21% and moderate-to-severe (mMRC 3 or 4) in 1%. The main correlates of dyspnea were older age, female sex, higher BMI and active smoking. Over a follow-up of 19±5 years, greater self-reported dyspnea severity was associated with worse prognosis. Mild dyspnea was associated with significantly heightened risk of HF (adjusted Hazard Ratio, HR,1.30; 95% CI: 1.16–1.46), MI (adjusted HR 1.34; 95%CI: 1.20–1.50), and death (adjusted HR 1.16; 95%CI: 1.06–1.26), with moderate/severe dyspnea associated with an even greater risk (adjusted HR 2.14, 95%CI: 1.59–2.89; 1.93, 95%CI: 1.41–2.56; 1.96, 95%CI: 1.55–2.48, respectively).

Conclusion

In community-dwelling persons free of previously diagnosed cardiopulmonary disease, self-reported dyspnea is common and, even when of mild intensity, it is independently associated with a greater risk of incident HF, MI, and death. Our data emphasize the prognostic importance of even mild self-reported dyspnea for cardiovascular outcomes.

Race and Sex Differences in the Incidence and Prognostic Significance of Silent Myocardial Infarction in the Atherosclerosis Risk in Communities (ARIC) Study

BACKGROUND

Race and sex differences in silent myocardial infarction (SMI) are not well established.

METHODS AND RESULTS

The analysis included 9498 participants from the Atherosclerosis Risk in Communities (ARIC) study who were free of cardiovascular disease at baseline (visit 1, 1987-1989). Incident SMI was defined as ECG evidence of MI without clinically documented MI (CMI) after the baseline until ARIC visit 4 (1996-1998). Coronary heart disease and all-cause deaths were ascertained starting from ARIC visit 4 until 2010. During a median follow-up of 8.9 years, 317 participants (3.3%) developed SMI and 386 (4.1%) developed CMI. The incidence rates of both SMI and CMI were higher in men (5.08 and 7.96 per 1000-person years, respectively) than in women (2.93 and 2.25 per 1000-person years, respectively; P<0.0001 for both). Blacks had a nonsignificantly higher rate of SMI than whites (4.45 versus 3.69 per 1000-person years; P=0.217), but whites had higher rate of CMI than blacks (5.04 versus 3.24 per 1000-person years; P=0.002). SMI and CMI (compared with no MI) were associated with increased risk of coronary heart disease death (hazard ratio, 3.06 [95% confidence interval, 1.88-4.99] and 4.74 [95% confidence interval, 3.26-6.90], respectively) and all-cause mortality (hazard ratio, 1.34 [95% confidence interval, 1.09-1.65] and 1.55 [95% confidence interval, 1.30-1.85], respectively). However, SMI and CMI were associated with increased mortality among both men and women, with potentially greater increased risk among women (interaction P=0.089 and 0.051, respectively). No significant interactions by race were detected.

CONCLUSIONS

SMI represents >45% of incident MIs and is associated with poor prognosis. Race and sex differences in the incidence and prognostic significance of SMI exist that may warrant considering SMI in personalized assessments of coronary heart disease risk.

Midlife Alcohol Consumption and the Risk of Stroke in the Atherosclerosis Risk in Communities Study

BACKGROUND AND PURPOSE

Alcohol consumption is common in the United States and may confer beneficial cardiovascular effects at light-to-moderate doses. The alcohol-stroke relationship remains debated. We estimated the relationship between midlife, self-reported alcohol consumption and ischemic stroke and intracerebral hemorrhage (ICH) in a biracial cohort.

METHODS

We examined 12,433 never and current drinkers in the Atherosclerosis Risk in Communities study, aged 45 to 64 years at baseline. Participants self-reported usual drinks per week of beer, wine, and liquor at baseline. We used multivariate Cox proportional hazards regression to assess the association of current alcohol consumption relative to lifetime abstention with incident ischemic stroke and ICH and modification by sex-race group. We modeled alcohol intake with quadratic splines to further assess dose-response relationships.

RESULTS

One third of participants self-reported abstention, 39% and 24%, respectively, consumed ≤3 and 4 to 17 drinks/wk, and only 5% reported heavier drinking. There were 773 ischemic strokes and 81 ICH over follow-up (median≈22.6 years). For ischemic stroke, light and moderate alcohol consumption were not associated with incidence (hazard ratios, 0.98; 95% CI, 0.79-1.21; 1.06, 0.84-1.34), whereas heavier drinking was associated with a 31% increased rate relative to abstention (hazard ratios, 1.31; 95% CI, 0.92-1.86). For ICH, moderate-to-heavy (hazard ratios, 1.99; 95% CI, 1.07-3.70), but not light, consumption increased incidence.

CONCLUSIONS

Self-reported light-to-moderate alcohol consumption at midlife was not associated with reduced stroke risk compared with abstention over 20 years of follow-up in the Atherosclerosis Risk in Communities study. Heavier consumption increased the risk for both outcomes as did moderate intake for ICH.

Atrial Fibrillation and Risk of ST-Segment-Elevation Versus Non-ST-Segment-Elevation Myocardial Infarction: The Atherosclerosis Risk in Communities (ARIC) Study

BACKGROUND

It has recently been reported that atrial fibrillation (AF) is associated with an increased risk of myocardial infarction (MI). However, the mechanism underlying this association is currently unknown. Further study of the relationship of AF with the type of MI (ST-segment-elevation MI [STEMI] versus non-ST-segment-elevation MI [NSTEMI]) might shed light on the potential mechanisms.

METHODS AND RESULTS

We examined the association between AF and incident MI in 14 462 participants (mean age, 54 years; 56% women; 26% blacks) from the Atherosclerosis Risk in Communities (ARIC) study who were free of coronary heart disease at baseline (1987-1989) with follow-up through December 31, 2010. AF cases were identified from study visit ECGs and by review of hospital discharge records. Incident MI and its types were ascertained by an independent adjudication committee. Over a median follow-up of 21.6 years, 1374 MI events occurred (829 NSTEMIs, 249 STEMIs, 296 unclassifiable MIs). In a multivariable-adjusted model, AF (n=1545) as a time-varying variable was associated with a 63% increased risk of MI (hazard ratio,1.63; 95% confidence interval, 1.32-2.02). However, AF was associated with NSTEMI (hazard ratio, 1.80; 95% confidence interval, 1.39-2.31) but not STEMI (hazard ratio, 0.49; 95% confidence interval, 0.18-1.34; P for hazard ratio comparison=0.004). Combining the unclassifiable MI group with either STEMI or NSTEMI did not change this conclusion. The association between AF and MI, total and NSTEMI, was stronger in women than in men (P for interaction <0.01 for both).

CONCLUSIONS

AF is associated with an increased risk of incident MI, especially in women. However, this association is limited to NSTEMI.

Race and Vitamin D Binding Protein Gene Polymorphisms Modify the Association of 25-Hydroxyvitamin D and Incident Heart Failure: The ARIC (Atherosclerosis Risk in Communities) Study

OBJECTIVES

This study sought to determine if low serum 25-hydroxyvitamin D (25[OH]D) is associated with incident heart failure (HF) and if the association is: 1) partly mediated by traditional cardiovascular risk factors; 2) stronger among whites than blacks; and 3) stronger among those genetically predisposed to having high levels of vitamin D binding protein (DBP).

BACKGROUND

Suboptimal 25(OH)D is a potential cardiovascular risk factor.

METHODS

A total of 12,215 ARIC (Atherosclerosis Risk in Communities) study participants free of HF at baseline (1990 to 1992; median age, 56; 24% black) were followed through 2010. Total serum 25(OH)D was measured at baseline using liquid chromatography-mass spectrometry. Incident HF events were identified by a hospital discharge code of ICD9-428 and parallel International Classification of Diseases codes for HF deaths.

RESULTS

During 21 years of follow-up, 1,799 incident HF events accrued. The association between 25(OH)D and HF varied by race (p-interaction = 0.02). Among whites, risk was 2-fold higher for those in the lowest (≤17 ng/ml) versus highest (≥31 ng/ml) quintile of 25(OH)D. The association was attenuated but remained significant with covariate adjustment. In blacks there was no overall association. In both races, those with low 25(OH)D and the rs7041 G allele, which predisposes to high DBP, were at greater risk (p-interaction = 0.01).

CONCLUSIONS

Low serum 25(OH)D was independently associated with incident HF among whites, but not among blacks. However, in both races, low 25(OH)D was associated with HF risk among those genetically predisposed to high DBP. These findings provide novel insight into metabolic differences that may underlie racial variation in the association between 25(OH)D and cardiovascular risk.

Association between hospitalization for pneumonia and subsequent risk of cardiovascular disease

IMPORTANCE

The risk of cardiovascular disease (CVD) after infection is poorly understood.

OBJECTIVE

To determine whether hospitalization for pneumonia is associated with an increased short-term and long-term risk of CVD.

DESIGN, SETTINGS, AND PARTICIPANTS

We examined 2 community-based cohorts: the Cardiovascular Health Study (CHS, n = 5888; enrollment age, ≥65 years; enrollment period, 1989-1994) and the Atherosclerosis Risk in Communities study (ARIC, n = 15,792; enrollment age, 45-64 years; enrollment period, 1987-1989). Participants were followed up through December 31, 2010. We matched each participant hospitalized with pneumonia to 2 controls. Pneumonia cases and controls were followed for occurrence of CVD over 10 years after matching. We estimated hazard ratios (HRs) for CVD at different time intervals, adjusting for demographics, CVD risk factors, subclinical CVD, comorbidities, and functional status.

EXPOSURES

Hospitalization for pneumonia.

MAIN OUTCOMES AND MEASURES

Incident CVD (myocardial infarction, stroke, and fatal coronary heart disease).

RESULTS

Of 591 pneumonia cases in CHS, 206 had CVD events over 10 years after pneumonia hospitalization. CVD risk after pneumonia was highest in the first year. CVD occurred in 54 cases and 6 controls in the first 30 days (HR, 4.07; 95% CI, 2.86-5.27); 11 cases and 9 controls between 31 and 90 days (HR, 2.94; 95% CI, 2.18-3.70); and 22 cases and 55 controls between 91 days and 1 year (HR, 2.10; 95% CI, 1.59-2.60). Additional CVD risk remained elevated into the tenth year, when 4 cases and 12 controls developed CVD (HR, 1.86; 95% CI, 1.18-2.55). In ARIC, of 680 pneumonia cases, 112 had CVD over 10 years after hospitalization. CVD occurred in 4 cases and 3 controls in the first 30 days (HR, 2.38; 95% CI, 1.12-3.63); 4 cases and 0 controls between 31 and 90 days (HR, 2.40; 95% CI, 1.23-3.47); 11 cases and 8 controls between 91 days and 1 year (HR, 2.19; 95% CI, 1.20-3.19); and 8 cases and 7 controls during the second year (HR, 1.88; 95% CI, 1.10-2.66). After the second year, the HRs were no longer statistically significant.

CONCLUSIONS AND RELEVANCE

Hospitalization for pneumonia was associated with increased short-term and long-term risk of CVD, suggesting that pneumonia may be a risk factor for CVD.

Bundle branch blocks and the risk of mortality in the Atherosclerosis Risk in Communities study

AIMS

The main objective of our study was to evaluate the associations between different categories of bundle branch blocks (BBBs) and mortality and to consider possible impact of QRS prolongation in these associations.

METHODS

This analysis included 15 408 participants (mean age 54 years, 55.2% women, and 26.9% blacks) from the Atherosclerosis Risk in Communities study. We used Cox regression to examine associations between left BBB (LBBB), right BBB (RBBB) and indetermined type of ventricular conduction defect [intraventricular conduction defect (IVCD)] with coronary heart disease (CHD) death and all-cause mortality.

RESULTS

During a mean 21 years of follow-up, 4767 deaths occurred; of these, 728 were CHD deaths. Compared to No-BBB, LBBB and IVCD were strongly associated with increased CHD death (hazard ratios 4.11 and 3.18, respectively; P < 0.001 for both). Furthermore, compared to No-BBB with QRS duration less than 100 ms, CHD mortality risk was increased 1.33-fold for the No-BBB group with QRS duration 100-109 ms, and 1.48-fold with QRS duration 110-119 ms, 3.52-fold for pooled LBBB-IVCD group with QRS duration less than 140 ms and 4.96-fold for pooled LBBB-IVCD group with QRS duration at least 140 ms (P < 0.001). However, mortality risk was not significantly increased for lone RBBB. For all-cause mortality, trends similar to those for CHD death were observed within the BBB groups, although at lower levels of risk.

CONCLUSION

Prevalent LBBB and IVCD, but not RBBB, are associated with increased risk of CHD death and all-cause mortality. Mortality risk is further increased as the QRS duration is prolonged above 140 ms.

Ventricular conduction defects and the risk of incident heart failure in the Atherosclerosis Risk in Communities (ARIC) Study

BACKGROUND

We evaluated the risk of incident heart failure (HF) associated with various categories of ventricular conduction defects (VCDs) and examined the impact of QRS duration on the risk of HF.

METHODS AND RESULTS

This analysis included 14,478 participants from the Atherosclerosis Risk in Communities (ARIC) study who were free of HF at baseline. VCDs (n = 377) were categorized into right and left bundle branch blocks (RBBB and LBBB, respectively), bifascicular BBB (RBBB with fascicular block), indeterminate-type VCD (IVCD), and pooled VCD group excluding lone RBBB. During an average of 18 years' follow-up, 1,772 participants were hospitalized for incident HF. Compared with no VCD, LBBB and pooled VCD were strongly associated with increased risk of incident HF (multivariable hazard ratios 2.87 and 2.29, respectively). Compared with no VCD with QRS duration <100 ms, HF risk was 1.17-fold for the no VCD group with QRS duration 100-119 ms, 1.97-fold for the pooled VCD group with QRS duration 120-139 ms, and 3.25-fold for the pooled VCD group with QRS duration ≥140 ms. HF risk for the pooled VCD group remained significant (1.74-fold for QRS duration 120-139 ms and 2.81-fold for QRS duration ≥140 ms) in the subgroup free from cardiovascular disease at baseline. Lone RBBB was not associated with incident HF.

CONCLUSIONS

VCDs except for isolated RBBB are strong predictors of incident HF, and HF risk is further increased as the QRS duration is prolonged >140 ms.

Prevalence of metabolic syndrome among Hispanics/Latinos of diverse background: the Hispanic Community Health Study/Study of Latinos

OBJECTIVE

Approximately one-third of the adult U.S. population has the metabolic syndrome. Its prevalence is the highest among Hispanic adults, but variation by Hispanic/Latino background is unknown. Our objective was to quantify the prevalence of the metabolic syndrome among men and women 18-74 years of age of diverse Hispanic/Latino background.

RESEARCH DESIGN AND METHODS

Two-stage area probability sample of households in four U.S. locales, yielding 16,319 adults (52% women) who self-identified as Cuban, Dominican, Mexican, Puerto Rican, Central American, or South American. The metabolic syndrome was defined according to the American Heart Association/National Heart, Lung, and Blood Institute 2009 Joint Scientific Statement. The main outcome measures were age-standardized prevalence of the metabolic syndrome per the harmonized American Heart Association/National Heart, Lung, and Blood Institute definition and its component abnormalities.

RESULTS

The metabolic syndrome was present in 36% of women and 34% of men. Differences in the age-standardized prevalence were seen by age, sex, and Hispanic/Latino background. The prevalence of the metabolic syndrome among those 18-44, 45-64, and 65-74 years of age was 23%, 50%, and 62%, respectively, among women; and 25%, 43%, and 55%, respectively, among men. Among women, the metabolic syndrome prevalence ranged from 27% in South Americans to 41% in Puerto Ricans. Among men, prevalences ranged from 27% in South Americans to 35% in Cubans. In those with the metabolic syndrome, abdominal obesity was present in 96% of the women compared with 73% of the men; more men (73%) than women (62%) had hyperglycemia.

CONCLUSIONS

The burden of cardiometabolic abnormalities is high in Hispanic/Latinos but varies by age, sex, and Hispanic/Latino background. Hispanics/Latinos are thus at increased, but modifiable, predicted lifetime risk of diabetes and its cardiovascular sequelae.

Usefulness of electrocardiographic QRS/T angles with versus without bundle branch blocks to predict heart failure (from the Atherosclerosis Risk in Communities Study)

Repolarization abnormalities in the setting of bundle branch blocks (BBB) are generally ignored. We used Cox regression models to determine hazard ratios (HRs) with 95% confidence intervals (CIs) for incident heart failure (HF) associated with wide spatial and frontal QRS/T angle (upper twenty-fifth percentile of each) in men and women with and without BBB. This analysis included 14,478 participants (54.6% women, 26.4% blacks, 377 [2.6%] with BBB) from the Atherosclerosis Risk in Communities Study who were free of HF at baseline. Using No-BBB with normal spatial QRS/T angle as the reference group, the risk for HF in multivariable adjusted models was increased 51% for No-BBB with wide spatial QRS/T angle (HR 1.51, 95% CI 1.37 to 1.66), 48% for BBB with normal spatial QRS/T angle (HR 1.48, 95% CI 1.17 to 1.88), and the risk for incident HF was increased more than threefold for BBB with wide spatial QRS/T angle (HR 3.37, 95% CI 2.47 to 4.60). The results were consistent across subgroups by gender. Similar results were observed for the frontal plane QRS/T angle. In the pooled BBB group excluding right BBB, a positive T wave in lead aVR and heart rate 70 bpm and higher were also potent predictors of incident HF similar to the QRS/T angles. In conclusion, both BBB and wide QRS/T angles are predictive of HF, and concomitant presence of both carries a much higher risk than for either predictor alone. These findings suggest that repolarization abnormalities in the setting of BBB should not be considered benign or an expected consequence of BBB.

Atrial fibrillation and cognitive decline-the role of subclinical cerebral infarcts: the atherosclerosis risk in communities study

BACKGROUND AND PURPOSE

The mechanism underlying the association of atrial fibrillation (AF) with cognitive decline in stroke-free individuals is unclear. We examined the association of incident AF with cognitive decline in stroke-free individuals, stratified by subclinical cerebral infarcts (SCIs) on brain MRI scans.

METHODS

We analyzed data from 935 stroke-free participants (mean age±SD, 61.5±4.3 years; 62% women; and 51% black) from 1993 to 1995 through 2004 to 2006 in the Atherosclerosis Risk in Communities Study, a biracial community-based prospective cohort study. Cognitive testing (including the digit symbol substitution and the word fluency tests) was performed in 1993 to 1995, 1996 to 1998, and 2004 to 2006 and brain MRI scans in 1993 to 1995 and 2004 to 2006.

RESULTS

During follow-up, there were 48 incident AF events. Incident AF was associated with greater annual average rate of decline in digit symbol substitution (-0.77; 95% confidence interval, -1.55 to 0.01; P=0.054) and word fluency (-0.80; 95% confidence interval, -1.60 to -0.01; P=0.048). Among participants without SCIs on brain MRI scans, incident AF was not associated with cognitive decline. In contrast, incident AF was associated with greater annual average rate of decline in word fluency (-2.65; 95% confidence interval, -4.26 to -1.03; P=0.002) among participants with prevalent SCIs in 1993 to 1995. Among participants who developed SCIs during follow-up, incident AF was associated with a greater annual average rate of decline in digit symbol substitution (-1.51; 95% confidence interval, -3.02 to -0.01; P=0.049).

CONCLUSIONS

The association of incident AF with cognitive decline in stroke-free individuals can be explained by the presence or development of SCIs, raising the possibility of anticoagulation as a strategy to prevent cognitive decline in AF.

Epidemiology and long-term clinical and biologic risk factors for pneumonia in community-dwelling older Americans: analysis of three cohorts

BACKGROUND

Preventing pneumonia requires better understanding of incidence, mortality, and long-term clinical and biologic risk factors, particularly in younger individuals.

METHODS

This was a cohort study in three population-based cohorts of community-dwelling individuals. A derivation cohort (n = 16,260) was used to determine incidence and survival and develop a risk prediction model. The prediction model was validated in two cohorts (n = 8,495). The primary outcome was 10-year risk of pneumonia hospitalization.

RESULTS

The crude and age-adjusted incidences of pneumonia were 6.71 and 9.43 cases/1,000 person-years (10-year risk was 6.15%). The 30-day and 1-year mortality were 16.5% and 31.5%. Although age was the most important risk factor (range of crude incidence rates, 1.69-39.13 cases/1,000 person-years for each 5-year increment from 45-85 years), 38% of pneumonia cases occurred in adults < 65 years of age. The 30-day and 1-year mortality were 12.5% and 25.7% in those < 65 years of age. Although most comorbidities were associated with higher risk of pneumonia, reduced lung function was the most important risk factor (relative risk = 6.61 for severe reduction based on FEV1 by spirometry). A clinical risk prediction model based on age, smoking, and lung function predicted 10-year risk (area under curve [AUC] = 0.77 and Hosmer-Lemeshow [HL] C statistic = 0.12). Model discrimination and calibration were similar in the internal validation cohort (AUC = 0.77; HL C statistic, 0.65) but lower in the external validation cohort (AUC = 0.62; HL C statistic, 0.45). The model also calibrated well in blacks and younger adults. C-reactive protein and IL-6 were associated with higher pneumonia risk but did not improve model performance.

CONCLUSIONS

Pneumonia hospitalization is common and associated with high mortality, even in younger healthy adults. Long-term risk of pneumonia can be predicted in community-dwelling adults with a simple clinical risk prediction model.

APOM and high-density lipoprotein cholesterol are associated with lung function and per cent emphysema

Chronic obstructive pulmonary disease (COPD) is linked to cardiovascular disease; however, there are few studies on the associations of cardiovascular genes with COPD. We assessed the association of lung function with 2100 genes selected for cardiovascular diseases among 20 077 European-Americans and 6900 African-Americans. We performed replication of significant loci in the other racial group and an independent consortium of Europeans, tested the associations of significant loci with per cent emphysema and examined gene expression in an independent sample. We then tested the association of a related lipid biomarker with forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) ratio and per cent emphysema. We identified one new polymorphism for FEV1/FVC (rs805301) in European-Americans (p=1.3×10(-6)) and a second (rs707974) in the combined European-American and African-American analysis (p=1.38×10(-7)). Both single-nucleotide polymorphisms (SNPs) flank the gene for apolipoprotein M (APOM), a component of high-density lipoprotein (HDL) cholesterol. Both were replicated in an independent cohort. SNPs in a second gene related to apolipoprotein M and HDL, PCSK9, were associated with FEV1/FVC ratio among African-Americans. rs707974 was associated with per cent emphysema among European-Americans and African-Americans and APOM expression was related to FEV1/FVC ratio and per cent emphysema. Higher HDL levels were associated with lower FEV1/FVC ratio and greater per cent emphysema. These findings suggest a novel role for the apolipoprotein M/HDL pathway in the pathogenesis of COPD and emphysema.

Social isolation, vital exhaustion, and incident heart failure: findings from the Atherosclerosis Risk in Communities Study

AIMS

Prospective studies have shown that social isolation (i.e. lack of social contacts) predicts incident coronary heart disease (CHD), but it is unclear whether it predicts incident heart failure (HF) and what factors might mediate this association. HF patients may be more susceptible to social isolation as they tend to be older and may have disrupted social relationships due to life course factors (e.g. retirement or bereavement). We prospectively examined whether individuals with higher vs. low social isolation have a higher incidence of HF and determined whether this association is mediated by vital exhaustion.

METHODS AND RESULTS

We estimated incident HF hospitalization or death among 14 348 participants from Visit 2 (1990-1992) in the Atherosclerosis Risk in Communities (ARIC) study using Cox proportional hazard models which were sequentially adjusted for age, race/study community, gender, current smoking, alcohol use, and co-morbidities. We conducted mediation analyses according to the Baron and Kenny method. After a median follow-up of 16.9 person-years, 1727 (13.0%) incident HF events occurred. The adjusted hazard of incident HF was greater for those in the higher vs. low social isolation risk group (hazard ratio 1.21, 95% confidence interval 1.08-1.35). Our data suggest that vital exhaustion strongly mediates the association between higher social isolation and incident HF (the percentage change in beta coefficient for higher vs. low social isolation groups after adjusting for vital exhaustion was 36%).

CONCLUSION

These data suggest that greater social isolation is an independent risk factor for incident HF, and this association appears to be strongly mediated by vital exhaustion.

Orthostatic hypotension as a risk factor for incident heart failure: the atherosclerosis risk in communities study

Heart failure causes significant morbidity and mortality. Distinguishing risk factors for incident heart failure can help identify at-risk individuals. Orthostatic hypotension may be a risk factor for incident heart failure; however, this association has not been fully explored, especially in nonwhite populations. The Atherosclerosis Risk in Communities Study included 12363 adults free of prevalent heart failure with baseline orthostatic measurements. Orthostatic hypotension was defined as a decrease of systolic blood pressure ≥20 mmHg or diastolic blood pressure ≥10 mmHg with position change from supine to standing. Incident heart failure was identified from hospitalization or death certificate disease codes. Over 17.5 years of follow-up, orthostatic hypotension was associated with incident heart failure with multivariable adjustment (hazard ratio: 1.54 [95% CI: 1.30-1.82]). This association was similar across race and sex groups. A stronger association was identified in younger individuals ≤55 years old (hazard ratio: 1.90 [95% CI: 1.41-2.55]) than in older individuals >55 years old (hazard ratio: 1.37 [95% CI: 1.12-1.69]; interaction P=0.034). The association between orthostatic hypotension and incident heart failure persisted with exclusion of those with diabetes mellitus, coronary heart disease, and those on antihypertensives or psychiatric or Parkinson disease medications. However, exclusion of those with hypertension somewhat attenuated the association (hazard ratio: 1.34 [95% CI: 1.00-1.80]). We identified orthostatic hypotension as a predictor of incident heart failure among middle-aged individuals, particularly those 45 to 55 years of age. This association may be partially mediated through hypertension. Orthostatic measures may enhance risk stratification for future heart failure development.