Bedroom allergen exposures in US households.

BACKGROUND: Bedroom allergen exposures contribute to allergic disease morbidity because people spend considerable time in bedrooms, where they come into close contact with allergen reservoirs. OBJECTIVE: We investigated participant and housing characteristics, including sociodemographic, regional, and climatic factors, associated with bedroom allergen exposures in a nationally representative sample of the US population. METHODS: Data were obtained from National Health and Nutrition Examination Survey 2005-2006. Information on participant and housing characteristics was collected by using questionnaires and environmental assessments. Concentrations of 8 indoor allergens (Alt a 1, Bla g 1, Can f 1, Fel d 1, Der f 1, Der p 1, Mus m 1, and Rat n 1) in dust vacuumed from nearly 7000 bedrooms were measured by using immunoassays. Exposure levels were classified as increased based on percentile (75th/90th) cutoffs. We estimated the burden of exposure to multiple allergens and used multivariable logistic regression to identify independent predictors for each allergen and household allergen burden. RESULTS: Almost all participants (>99%) had at least 1 and 74.2% had 3 to 6 allergens detected. More than two thirds of participants (72.9%) had at least 1 allergen and 18.2% had 3 or more allergens exceeding increased levels. Although exposure variability showed significant racial/ethnic and regional differences, high exposure burden to multiple allergens was most consistently associated with the presence of pets and pests, living in mobile homes/trailers and older and rental homes, and living in nonmetropolitan areas. CONCLUSIONS: Exposure to multiple allergens is common. Despite highly variable exposures, bedroom allergen burden is strongly associated with the presence of pets and pests.

Endotoxin Exposure: Predictors and Prevalence of Associated Asthma Outcomes in the United States.

RATIONALE: Inhaled endotoxin induces airway inflammation and is an established risk factor for asthma. The 2005-2006 National Health and Nutrition Examination Survey included measures of endotoxin and allergens in homes as well as specific IgE to inhalant allergens. OBJECTIVES: To understand the relationships between endotoxin exposure, asthma outcomes, and sensitization status for 15 aeroallergens in a nationally representative sample. METHODS: Participants were administered questionnaires in their homes. Reservoir dust was vacuum sampled to generate composite bedding and bedroom floor samples. We analyzed 7,450 National Health and Nutrition Examination Survey dust and quality assurance samples for their endotoxin content using extreme quality assurance measures. Data for 6,963 subjects were available, making this the largest study of endotoxin exposure to date. Log-transformed endotoxin concentrations were analyzed using logistic models and forward stepwise linear regression. Analyses were weighted to provide national prevalence estimates and unbiased variances. MEASUREMENTS AND MAIN RESULTS: Endotoxin exposure was significantly associated with wheeze in the past 12 months, wheeze during exercise, doctor and/or emergency room visits for wheeze, and use of prescription medications for wheeze. Models adjusted for age, sex, race and/or ethnicity, and poverty-to-income ratio and stratified by allergy status showed that these relationships were not dependent upon sensitization status but were worsened among those living in poverty. Significant predictors of higher endotoxin exposures were lower family income; Hispanic ethnicity; participant age; dog(s), cat(s), cockroaches, and/or smoker(s) in the home; and carpeted floors. CONCLUSIONS: In this U.S. nationwide representative sample, higher endotoxin exposure was significantly associated with measures of wheeze, with no observed protective effect regardless of sensitization status.

Prevalence of allergic sensitization in the United States: results from the National Health and Nutrition Examination Survey (NHANES) 2005-2006.

BACKGROUND: Allergic sensitization is an important risk factor for the development of atopic disease. The National Health and Nutrition Examination Survey (NHANES) 2005-2006 provides the most comprehensive information on IgE-mediated sensitization in the general US population. OBJECTIVE: We investigated clustering, sociodemographic, and regional patterns of allergic sensitization and examined risk factors associated with IgE-mediated sensitization. METHODS: Data for this cross-sectional analysis were obtained from NHANES 2005-2006. Participants aged 1 year or older (n = 9440) were tested for serum specific IgEs (sIgEs) to inhalant and food allergens; participants 6 years or older were tested for 19 sIgEs, and children aged 1 to 5 years were tested for 9 sIgEs. Serum samples were analyzed by using the ImmunoCAP System. Information on demographics and participants' characteristics was collected by means of questionnaire. RESULTS: Of the study population aged 6 years and older, 44.6% had detectable sIgEs, whereas 36.2% of children aged 1 to 5 years were sensitized to 1 or more allergens. Allergen-specific IgEs clustered into 7 groups that might have largely reflected biological cross-reactivity. Although sensitization to individual allergens and allergen types showed regional variation, the overall prevalence of sensitization did not differ across census regions, except in early childhood. In multivariate modeling young age, male sex, non-Hispanic black race/ethnicity, geographic location (census region), and reported pet avoidance measures were most consistently associated with IgE-mediated sensitization. CONCLUSIONS: The overall prevalence of allergic sensitization does not vary across US census regions, except in early life, although allergen-specific sensitization differs based on sociodemographic and regional factors. Biological cross-reactivity might be an important but not the sole contributor to the clustering of allergen-specific IgEs.

Social network, social support, and risk of incident stroke: Atherosclerosis Risk in Communities study.

BACKGROUND AND PURPOSE: Having a small social network and lack of social support have been associated with incident coronary heart disease; however, epidemiological evidence for incident stroke is limited. We assessed the longitudinal association of a small social network and lack of social support with risk of incident stroke and evaluated whether the association was partly mediated by vital exhaustion and inflammation. METHODS: The Atherosclerosis Risk in Communities study measured social network and social support in 13 686 men and women (mean, 57 years; 56% women; 24% black; 76% white) without a history of stroke. Social network was assessed by the 10-item Lubben Social Network Scale and social support by a 16-item Interpersonal Support Evaluation List-Short Form. RESULTS: During a median follow-up of 18.6 years, 905 incident strokes occurred. Relative to participants with a large social network, those with a small social network had a higher risk of stroke (hazard ratio [95% confidence interval], 1.44 [1.02-2.04]) after adjustment for demographics, socioeconomic variables, marital status, behavioral risk factors, and major stroke risk factors. Vital exhaustion, but not inflammation, partly mediated the association between a small social network and incident stroke. Social support was unrelated to incident stroke. CONCLUSIONS: In this sample of US community-dwelling men and women, having a small social network was associated with excess risk of incident stroke. As with other cardiovascular conditions, having a small social network may be associated with a modestly increased risk of incident stroke.

Birth weight and the risk of atrial fibrillation in whites and African Americans: the Atherosclerosis Risk In Communities (ARIC) study.

BACKGROUND: Low birth weight (LBW) has been associated with an increased risk of cardiovascular disease (CVD). A previous study, however, found higher risk of atrial fibrillation (AF) in individuals with higher birth weight (BW). To further understand this apparent paradox, we examined the relationship between AF and BW in the Atherosclerosis Risk in Communities (ARIC) cohort. METHODS: The analysis included 10,132 individuals free of AF at baseline (1996-1998), who provided BW information, were not born premature, and were not a twin. Self-reported BW was categorized as low (<2.5 kg), medium (2.5-4 kg), and high (>4.0 kg). AF incidence was ascertained from hospital discharge codes and death certificates. We used multivariable Cox proportional hazard models to determine the hazard ratios (HR) and 95% confidence intervals (CI) of AF across BW groups. RESULTS: During an average follow-up of 10.3 years, we identified 882 incident AF cases. LBW was associated with higher risk of AF. Compared to individuals in the medium BW category, the HR (95% CI) of AF was 1.33 (0.99, 1.78) for LBW and 1.00 (0.81, 1.24) for high BW after adjusting for sociodemographic variables (p for trend = 0.29). Additional adjustment for CVD risk factors did not attenuate the associations (HR 1.42, 95% CI 1.06, 1.90 for LBW and HR 0.86, 95% CI 0.69-1.07 for high BW, compared to medium BW, p for trend = 0.01). CONCLUSION: LBW was associated with a higher risk of AF. This association was independent of known predictors of AF and is consistent with that observed for other cardiovascular diseases.

An evaluation of emergency medical services stroke protocols and scene times.

BACKGROUND: Acute stroke patients require immediate medical attention. Therefore, American Stroke Association guidelines recommend that for suspected stroke cases, emergency medical services (EMS) personnel spend less than 15 minutes on-scene at least 90% of the time. However, not all EMS providers include specific scene time limits in their stroke patient care protocols. OBJECTIVE: We sought to determine whether having a protocol with a specific scene time limit was associated with less time EMS spent on scene. Methods. Stroke protocols from the 100 EMS systems in North Carolina were collected and abstracted for scene time instructions. Suspected stroke events occurring in 2009 were analyzed using data from the North Carolina Prehospital Medical Information System. Scene time was defined as the time from EMS arrival at the scene to departure with the patient. Quantile regression was used to estimate how the 90th percentile of the scene time distribution varied by systems with protocol instructions limiting scene time, adjusting for system patient volume and metropolitan status. RESULTS: In 2009, 23 EMS systems in North Carolina had no instructions regarding scene time; 73 had general instructions to minimize scene time; and 4 had a specific limit for scene time (i.e., 10 or 15 min). Among 9,723 eligible suspected stroke events, mean scene time was 15.9 minutes (standard deviation 6.9 min) and median scene time was 15.0 minutes (90th percentile 24.3 min). In adjusted quantile regression models, the estimated reduction in the 90th percentile scene time, comparing protocols with a specific time limit to no instructions, was 2.2 minutes (95% confidence interval 1.3, 3.1 min). The difference in 90th percentile scene time between general and absent instructions was not statistically different (0.7 min [95% confidence interval -0.1, 1.4 min]). CONCLUSION: Protocols with specific scene time limits were associated with EMS crews spending less time at the scene while general instructions were not. These findings suggest EMS systems can modestly improve scene times for stroke by specifying a time limit in their protocols.

Neighborhood socioeconomic disparities and 1-year case fatality after incident myocardial infarction: the Atherosclerosis Risk in Communities (ARIC) Community Surveillance (1992-2002).

BACKGROUND: Declines in case fatality post-myocardial infarction (MI) have been observed over the past 3 decades. Few studies report socioeconomic disparities in survival post-MI. METHODS: We assessed 1-year case fatality among 9,116 incident MI patients included in the Atherosclerosis Risk in Communities community surveillance from 1992 to 2002. Addresses of hospitalized MI patients were geocoded by a commercial vendor and linked to year 2000 United States Census tract-level neighborhood income (nINC) data. We estimated case fatality odds ratios and 95% CIs with a multinomial logistic model to quantify the association between nINC tertile and case fatality, comparing short- (within 28 days) and long-term (29-365 days) case fatality to no death 1 year post-MI. RESULTS: Overall, 1-year age-adjusted case fatality rates were highest among MI patients living in low-nINC areas, followed by medium- and high-nINC areas, respectively. We found significant odds ratio modification by race (P < .10) and formed race-nINC strata with high-nINC whites as the referent group. In multivariable models adjusting for age, gender, study community, and year of MI, low-nINC whites and low- and medium-nINC blacks had higher short-term case fatality than high-nINC whites. Low- and medium-nINC blacks had higher long-term case fatality compared with high-nINC whites. CONCLUSIONS: Differences in short- and long-term case fatality by neighborhood socioeconomic factors have not been systematically studied in the United States. Surveillance efforts can be expanded to incorporate measures of the neighborhood context to examine these associations over time.

Prevalence and sociodemographic correlates of antinuclear antibodies in the United States.

OBJECTIVE: To estimate the prevalence, types, and sociodemographic and biobehavioral correlates of antinuclear antibodies (ANAs) in the US. METHODS: We conducted a cross-sectional analysis of 4,754 individuals from the National Health and Nutrition Examination Survey 1999-2004. ANAs were assessed by indirect immunofluorescence. In ANA-positive individuals, cellular staining patterns were determined, and specific autoantibody reactivities were assessed by immunoprecipitation. RESULTS: The ANA prevalence in the US population of individuals ages 12 years and older was 13.8% (95% confidence interval [95% CI] 12.2-15.5%). ANA prevalence increased with age (P=0.01), and ANAs were more prevalent among females than males (17.8% versus 9.6%; P<0.001), with the female-to-male ratio peaking at 40-49 years of age. ANA prevalence was modestly higher in African Americans compared with whites (age-adjusted prevalence odds ratio [POR] 1.30, 95% CI 1.00-1.70). Remarkably, ANAs were less common in overweight and obese individuals (age-adjusted POR 0.74) than in persons of normal weight. No significant associations of ANA with education, family income, alcohol use, smoking history, serum levels of cotinine, or C-reactive protein were observed. In ANA-positive individuals, nuclear patterns were seen in 84.6%, cytoplasmic patterns were seen in 21.8%, and nucleolar patterns were seen in 6.1%; the most common specific autoantibodies were anti-Ro (3.9%) and anti-Su (2.4%). CONCLUSION: These findings suggest that more than 32 million persons in the US have ANAs, and that the prevalence is higher among females, older individuals, African Americans, and those with a normal body weight. These data will serve as a useful baseline for future investigations of predictors and changes in ANA prevalence over time.

Bilateral common carotid artery ultrasound for prediction of incident strokes using intima-media thickness and external diameter: an observational study.

BACKGROUND: External common carotid artery (CCA) diameter and intima-media thickness (IMT) are independently associated with incident stroke and other cardiovascular events. Arterial geometry such as large IMT and large diameter may reflect vulnerable plaques and so impact stroke risk. Finally, arterial changes that exist bilaterally may increase stroke risk. METHOD: We studied middle-aged men and women (n=7276) from a prospective observational study who had right (R) and left (L) CCA IMT and external diameters measured via B-mode ultrasound (1987-89) in order to categorize CCA geometry. Using side- and gender-specific IMT and diameter medians, we categorized each measurement as large (≥ median) vs. not large (< median) and defined four geometries: both IMT and diameter were large, only one parameter was large, or neither was large (reference group). Participants were followed for first time stroke through December 31, 1999. We used proportional hazards models to assess associations between right and left CCA geometries with new stroke. We also calculated positive and negative likelihood ratios (+LR and -LR) for CCA bilateral phenotypes as a measure of diagnostic accuracy. RESULTS: Presence of both large CCA IMT and large diameter on one side was associated with strong stroke risk even after risk factor adjustment (men: RCCA hazard ratio [HR]=3.7 95% confidence interval [CI]=1.9-7.4; LCCA HR=2.4 95% CI=1.4-4.4; women: RCCA HR=4.0 95% CI=1.5-10.5; LCCA HR=5.7 95% CI=1.7-19.0). Presence of both large IMT and large diameter bilaterally was the strongest predictor of stroke identifying 64% of women and 44% of men who developed strokes. This phenotype showed potential for predicting stroke among individuals (women: +LR=3.1, 95% CI=2.6-3.8; men: +LR=2.3, 95% CI=1.8-2.8). CONCLUSION: Bilateral carotid artery geometries may be useful for stroke risk prediction.

Emergency medical services capacity for prehospital stroke care in North Carolina.

INTRODUCTION: Prior assessments of emergency medical services (EMS) stroke capacity found deficiencies in education and training, use of protocols and screening tools, and planning for the transport of patients. A 2001 survey of North Carolina EMS providers found many EMS systems lacked basic stroke services. Recent statewide efforts have sought to standardize and improve prehospital stroke care. The objective of this study was to assess EMS stroke care capacity in North Carolina and evaluate statewide changes since 2001. METHODS: In June 2012, we conducted a web-based survey on stroke education and training and stroke care practices and policies among all EMS systems in North Carolina. We used the McNemar test to assess changes from 2001 to 2012. RESULTS: Of 100 EMS systems in North Carolina, 98 responded to our survey. Most systems reported providing stroke education and training (95%) to EMS personnel, using a validated stroke scale or screening tool (96%), and having a hospital prenotification policy (98%). Many were suboptimal in covering basic stroke educational topics (71%), always communicating stroke screen results to the destination hospital (46%), and always using a written destination plan (49%). Among 70 EMS systems for which we had data for 2001 and 2012, we observed significant improvements in education on stroke scales or screening tools (61% to 93%, P < .001) and use of validated stroke scales or screening tools (23% to 96%, P < .001). CONCLUSION: Major improvements in EMS stroke care, especially in prehospital stroke screening, have occurred in North Carolina in the past decade, whereas other practices and policies, including use of destination plans, remain in need of improvement.

Orthostatic hypotension and novel blood pressure-associated gene variants: Genetics of Postural Hemodynamics (GPH) Consortium.

AIMS: Orthostatic hypotension (OH), an independent predictor of mortality and cardiovascular events, strongly correlates with hypertension. Recent genome-wide studies have identified new loci influencing blood pressure (BP) in populations, but their impact on OH remains unknown. METHODS AND RESULTS: A total of 38 970 men and women of European ancestry from five population-based cohorts were included, of whom 2656 (6.8%) met the diagnostic criteria for OH (systolic/diastolic BP drop ≥ 20/10 mmHg within 3 min of standing). Thirty-one recently discovered BP-associated single nucleotide polymorphisms (SNPs) were examined using an additive genetic model and the major allele as referent. Relations between OH, orthostatic systolic BP response, and genetic variants were assessed by inverse variance-weighted meta-analysis. We found Bonferroni adjusted (P < 0.0016) significant evidence for association between OH and the EBF1 locus (rs11953630, per-minor-allele odds ratio, 95% confidence interval: 0.90, 0.85-0.96; P = 0.001), and nominal evidence (P < 0.05) for CYP17A1 (rs11191548: 0.85, 0.75-0.95; P = 0.005), and NPR3-C5orf23 (rs1173771: 0.92, 0.87-0.98; P= 0.009) loci. Among subjects not taking BP-lowering drugs, three SNPs within the NPPA/NPPB locus were nominally associated with increased risk of OH (rs17367504: 1.13, 1.02-1.24; P = 0.02, rs198358: 1.10, 1.01-1.20; P = 0.04, and rs5068: 1.22, 1.04-1.43; P = 0.01). Moreover, an ADM variant was nominally associated with continuous orthostatic systolic BP response in the adjusted model (P= 0.04). CONCLUSION: The overall association between common gene variants in BP loci and OH was generally weak and the direction of effect inconsistent with resting BP findings. These results suggest that OH and resting BP share few genetic components.

Performance of automated and manual coding systems for occupational data: a case study of historical records.

BACKGROUND: Occupational data are a common source of workplace exposure and socioeconomic information in epidemiologic research. We compared the performance of two occupation coding methods, an automated software and a manual coder, using occupation and industry titles from U.S. historical records. METHODS: We collected parental occupational data from 1920-40s birth certificates, Census records, and city directories on 3,135 deceased individuals in the Atherosclerosis Risk in Communities (ARIC) study. Unique occupation-industry narratives were assigned codes by a manual coder and the Standardized Occupation and Industry Coding software program. We calculated agreement between coding methods of classification into major Census occupational groups. RESULTS: Automated coding software assigned codes to 71% of occupations and 76% of industries. Of this subset coded by software, 73% of occupation codes and 69% of industry codes matched between automated and manual coding. For major occupational groups, agreement improved to 89% (kappa = 0.86). CONCLUSIONS: Automated occupational coding is a cost-efficient alternative to manual coding. However, some manual coding is required to code incomplete information. We found substantial variability between coders in the assignment of occupations although not as large for major groups.

Clinical outcomes among stroke patients receiving tissue plasminogen activator therapy beyond the 3-hour time window.

BACKGROUND: Tissue plasminogen activator therapy (t-PA) is associated with improved neurologic outcomes and reduced disability from ischemic stroke. The current guidelines stipulate that patients receive t-PA within 3 hours of symptom onset. However, actual practice patterns vary, and little is known about patient outcomes when t-PA is received outside of the recommended time window. METHODS: We examined mean length of hospital stay, t-PA-related complications, and in-hospital death by time of t-PA administration in North Carolina Stroke Care Collaborative (NCSCC) patients. The NCSCC includes 53 hospitals that enroll patients presenting with stroke-like symptoms. Of 40,907 patients enrolled between January 2005 and February 2010, 1070 (2.6%) received t-PA. Of these, 88.2% received t-PA within 3 hours of symptom onset ("early") and 30.3% received t-PA between 3 and 6 hours after symptom onset ("late"). RESULTS: Unadjusted mean length of stay (days) was longer among early patients (5.0 days; 95% confidence interval [CI], 4.7-5.3) than late patients (3.6 days; 95% CI, 3.1-4.2). t-PA-related complications were similar among early (7.0%; 55/781) and late patients (6.7%; 7/102; P = .89). The proportion of in-hospital deaths was similar among late (10.5%) and early patients (12.0%). We used multivariable logistic regression to estimate odds ratios (ORs) and 95% CIs for the associations between late t-PA status and patient outcomes. CONCLUSIONS: In models controlling for age, race, sex, arrival mode, and ambulatory status on admission, late t-PA was not associated with increased odds of complications or in-hospital deaths (OR, 0.89; 95% CI, 0.49-1.62). The risks and benefits of expansion of the t-PA time window in stroke patients merit further investigation.

Prehospital notification by emergency medical services reduces delays in stroke evaluation: findings from the North Carolina stroke care collaborative.

BACKGROUND AND PURPOSE: Individuals with stroke-like symptoms are recommended to receive rapid diagnostic evaluation. Emergency medical services (EMS) transport, compared with private modes, and hospital notification before arrival may reduce delays in evaluation. This study estimated associations between hospital arrival modes (EMS or private and with or without EMS prenotification) and times for completion and interpretation of initial brain imaging in patients with presumed stroke. METHODS: Among patients with suspected stroke identified and enrolled by the North Carolina Stroke Care Collaborative registry in 2008 to 2009, we analyzed data on arrival modes, meeting recommended targets for brain imaging completion and interpretation times (<25 minutes and <45 minutes since hospital arrival, respectively) and patient- and hospital-level characteristics. We used modified Poisson regression to estimate adjusted risk ratios and 95% CIs. RESULTS: Of 13 894 eligible patients, 21% had their brain imaging completed and 23% had their brain imaging interpreted by a physician within target times. Arrival by EMS (versus private transport) was associated with both brain imaging completed within 25 minutes of arrival (EMS with prenotification: risk ratio, 3.0; 95% CI, 2.1 to 4.1; EMS without prenotification: risk ratio, 1.9; 95% CI, 1.6 to 2.3) and brain imaging interpreted within 45 minutes (EMS with prenotification: risk ratio, 2.7; 95% CI, 2.3 to 3.3; EMS without prenotification: risk ratio, 1.7; 95% CI, 1.4 to 2.1). CONCLUSIONS: Patients with presumed stroke arriving to the hospital by EMS were more likely to receive brain imaging and have it interpreted by a physician in a timely manner than those arriving by private transport. Moreover, EMS arrivals with hospital prenotification experienced the most rapid evaluation.

Long-term effects of wealth on mortality and self-rated health status.

Epidemiologic studies seldom include wealth as a component of socioeconomic status. The authors investigated the associations between wealth and 2 broad outcome measures: mortality and self-rated general health status. Data from the longitudinal Panel Study of Income Dynamics, collected in a US population between 1984 and 2005, were used to fit marginal structural models and to estimate relative and absolute measures of effect. Wealth was specified as a 6-category variable: those with ≤0 wealth and quintiles of positive wealth. There were a 16%-44% higher risk and 6-18 excess cases of poor/fair health (per 1,000 persons) among the less wealthy relative to the wealthiest quintile. Less wealthy men, women, and whites had higher risk of poor/fair health relative to their wealthy counterparts. The overall wealth-mortality association revealed a 62% increased risk and 4 excess deaths (per 1,000 persons) among the least wealthy. Less wealthy women had between a 24% and a 90% higher risk of death, and the least wealthy men had 6 excess deaths compared with the wealthiest quintile. Overall, there was a strong inverse association between wealth and poor health status and between wealth and mortality.

Socioeconomic status and the trajectory of self-rated health.

BACKGROUND: self-rated health (SRH) likely reflects both mental and physical health domains, and is assessed by asking individuals to describe their health status. Poor SRH is associated with disease incidence and subsequent mortality. Changes in SRH across time in persons with different incident diseases are uncharacterised. METHODS: SRH was assessed in the Atherosclerosis Risk in Communities study via annual telephone interviews over a median of 17.6 years. Individual quadratic growth models were used for repeated measures of SRH in persons who remained disease-free during follow-up (n = 11,188), as well as among those who were diagnosed with myocardial infarction (MI; n = 1,071), stroke (n = 809), heart failure (HF; n = 1,592) or lung cancer (n = 433) and those who underwent a cardiac revascularisation procedure (n = 1,340) during follow-up. RESULTS: among disease-free participants and across time, there was a trend for lowest mean SRH among persons living in low socioeconomic areas and highest mean SRH among persons living in high socioeconomic areas. Factors contributing to the decline in SRH over time included advanced age, lower educational attainment, smoking and obesity. CONCLUSION: addressing factors related to poor SRH trajectories among patients pre- and post-incident disease may favourably affect health outcomes among patients regardless of type of disease.

Blood pressure and white-matter disease progression in a biethnic cohort: Atherosclerosis Risk in Communities (ARIC) study.

BACKGROUND AND PURPOSE: Blood pressure (BP) is a predictor of concurrent and subsequently measured white-matter hyperintensity (WMH), but longitudinal studies of WMH changes and data in black participants are lacking. We hypothesized that WMH progression would be (1) strongly related to BP in blacks and whites and (2) predicted more strongly by earlier (midlife) or cumulative BP measurements than by measures at older ages. METHODS: Participants were 983 individuals (49% black) from the Atherosclerosis Risk in Communities (ARIC) Study who underwent cerebral magnetic resonance imaging in 1993-1995 and 2004-2006. Associations between BP (measured at each of 5 visits, in addition to a time-averaged cumulative BP) and progression of WMHs were analyzed and compared. RESULTS: Cumulative systolic BP (SBP) was the strongest BP predictor of WMH progression in adjusted models. Higher cumulative SBP (by 20 mm Hg) was associated with greater progression of WMHs and was similar in blacks (2.5 cm(3), P<0.0001) and whites (2.6 cm(3), P<0.0001). Higher cumulative SBP (per 20 mm Hg) was also associated with being in the top quintile of WMH progression (adjusted odds ratio=2.0; 95% CI, 1.6 to 2.6). Earlier SBP measurements were stronger predictors of WMH progression than were later SBP measurements, but in blacks only. CONCLUSIONS: In this population-based cohort, cumulative SBP was a stronger predictor of WMH progression than SBP from individual visits, in both blacks and whites. Earlier BPs were stronger predictors than BPs measured at later time points in blacks only.

Orthostatic hypotension and cognitive function: the Atherosclerosis Risk in Communities Study.

BACKGROUND: To examine the association between orthostatic hypotension (OH) and cognitive function in middle-aged adults. METHODS: Participants were 12,702 men and women from the Atherosclerosis Risk in Communities Study. OH was defined as decrease in systolic blood pressure (BP) by > or =20 mm Hg or diastolic BP by > or =10 mm Hg upon standing. At the 2nd and the 4th follow-up examinations, cognitive function was assessed using the Delayed Word Recall Test, Digit Symbol Substitution Test (DSST) and Word Fluency Test (WFT). RESULTS: After age adjustment, those with OH were more likely to be in the lowest quintile of the DSST (OR = 1.34, 95% CI = 1.12-1.62) and WFT (OR = 1.25, 95% CI = 1.03-1.51) than were those without OH. After adjustment for sociodemographic and cardiovascular risk factors, associations were no longer significant. In age-adjusted models only, OH was associated with increased odds of being in the greatest quintile of decline in DSST score between visits 2 and 4 (OR = 1.28, 95% CI = 1.04-1.58). CONCLUSIONS: OH was associated with less favorable cognitive function, but this association was largely attributable to demographic and cardiovascular risk factors. Episodic asymptomatic hypotension in middle age may not be an independent cause of cognitive decline. Further study, including emphasis on neuroimaging, is needed.

Military combat and burden of subclinical atherosclerosis in middle aged men: the ARIC study.

BACKGROUND: Studies of the cardiovascular consequences of combat stress are few and inconclusive. OBJECTIVE: The association between combat exposure and subclinical atherosclerosis at Atherosclerosis Risk in Communities (ARIC) Study visits 1 (1987-1989) and 2 (1990-1992) was assessed among 5347 men from four U.S. communities. METHODS: Measured an average of 36 years after military entry, carotid intima-media thickness (CIMT) and carotid plaque among non-combat veterans (n=2127) were compared with non-veterans (n=2042) and veterans reporting combat experience (n=1178). RESULTS: Compared to non-combat veterans, non-veterans (risk difference (RD): 10.61; 95% confidence interval (CI): 0.81, 20.41) and combat veterans (RD: 12.79; 95% CI: 0.72, 24.86) had higher age-adjusted mean CIMT. Differences remained for combat veterans after adjustment for race, father's education and age at service entry but not years of service and for non-veterans after adjustment for race but not father's education. No differences in carotid plaque were noted. CONCLUSION: Results do not suggest that combat has a long-term detrimental effect on subclinical atherosclerosis among men.

A multicenter evaluation of the ABCD2 score's accuracy for predicting early ischemic stroke in admitted patients with transient ischemic attack.

STUDY OBJECTIVE: We evaluate, in admitted patients with transient ischemic attack, the accuracy of the ABCD(2) (age [A], blood pressure [B], clinical features [weakness/speech disturbance] [C], transient ischemic attack duration [D], and diabetes history [D]) score in predicting ischemic stroke within 7 days. METHODS: At 16 North Carolina hospitals, we enrolled a prospective, nonconsecutive sample of admitted patients with transient ischemic attack and with no stroke history, presenting within 24 hours of transient ischemic attack symptom onset. We conducted a medical record review to determine ischemic stroke outcomes within 7 days. According to a modified Rankin Scale Score, strokes were classified as disabling (>2) or nondisabling (< or =2). RESULTS: During a 35-month period, we enrolled 1,667 patients, of whom 373 (23%) received a diagnosis of an ischemic stroke within 7 days. Eighteen percent (69/373) of all strokes were disabling. We were unable to calculate an ABCD(2) score in 613 patients (37%); however, our imputed analysis indicated this did not significantly alter results. The discriminatory power of the ABCD(2) score was modest for ischemic stroke in 7 days (c statistic 0.59), and fair for disabling ischemic stroke within 7 days (c statistic 0.71). Patients characterized as low risk according to ABCD(2) score (< or =3) were at low risk for experiencing a disabling stroke within 7 days, with a negative likelihood ratio of 0.16 (95% confidence interval [CI] 0.04 to 0.64) with missing values excluded and 0.34 (95% CI 0.15 to 0.76) when missing values were imputed. CONCLUSION: Our analysis suggests the best application of the ABCD(2) score may be to identify patients at low risk for an early disabling ischemic stroke. Further study of the ability to determine an ABCD(2) score in all patients is needed, along with validation in a large, consecutive population of patients with transient ischemic attack.