924 research outputs found
Recommended from our members
Fuel Cells for Auxiliary Power in Trucks: Requirements, Benefits and Marketability
Public agencies and the trucking industry have recognized the idling of heavy-duty trucks as a significant contributor to fuel consumption and air pollution. Several potential technical solutions are in development, including the utilization of auxiliary power units (APUs). Using fuel cell APUs could be a promising alternative to idling with substantial fuel consumption, emissions, cost, and noise benefits, while serving as a niche for relatively early fuel cell technology market introduction. This paper, using a probabilistic Monte Carlo framework, reports on efforts to characterize existing data on idling trucks, develop an ADVISOR-based vehicle APU model that accurately depicts how utilizing fuel cell APUs to replace heavy-duty truck idling could be implemented, quantify energy consumption reductions, and analyze the economic benefits of the APU. The analysis shows that if fuel cell research targets for APUs are met over the next decade, a market in the tens of thousands of units may be possible in the line-haul trucking industry, and substantial diesel consumption reductions would result
Synergistic and Non-synergistic Associations for Cigarette Smoking and Non-tobacco Risk Factors for Cardiovascular Disease Incidence in the Atherosclerosis Risk In Communities (ARIC) Study
Cigarette smoking, various metabolic and lipid-related factors and hypertension are well-recognized cardiovascular disease (CVD) risk factors. Since smoking affects many of these factors, use of a single imprecise smoking metric, e.g., ever or never smoked, may allow residual confounding and explain inconsistencies in current assessments of interactions. Using a comprehensive model in pack-years and cigarettes/day for the complex smoking-related relative risk (RR) of CVD to reduce residual confounding, we evaluated interactions with non-tobacco risk factors, including additive (non-synergistic) and multiplicative (synergistic) forms. Data were from the prospective Atherosclerosis Risk in Communities (ARIC) Study from four areas of the U.S. recruited in 1987-89 with follow-up through 2008. Analyses included 14,127 participants, 207,693 person-years and 2,857 CVD events. Analyses revealed distinct interactions with smoking: including statistical consistency with additive (body mass index, waist to hip ratio, diabetes mellitus, glucose, insulin, high density lipoproteins [HDL] and HDL(2)); and multiplicative (hypertension, total cholesterol, low density lipoproteins, apolipoprotein B, total cholesterol to HDL ratio and HDL(3)) associations, as well as indeterminate (apolipoprotein A-I and triglycerides) associations. The forms of the interactions were revealing but require confirmation. Improved understanding of joint associations may help clarify the public health burden of smoking for CVD, links between etiologic factors and biological mechanisms, and the consequences of joint exposures, whereby synergistic associations highlight joint effects and non-synergistic associations suggest distinct contributions. Joint associations for cigarette smoking and non-tobacco risk factors were distinct, revealing synergistic/multiplicative (hypertension, TC, LDL, apoB, TC/HDL, HDL(3)), non-synergistic/additive (BMI, WHR, DM, glucose, insulin, HDL, HDL(2)) and indeterminate (apoA-I and TRIG) associations. If confirmed, these results may help better define the public health burden of smoking on CVD risk and identify links between etiologic factors and biologic mechanisms, where synergistic associations highlight joint impacts and non-synergistic associations suggest distinct contributions from each factor
Dietary intake and peripheral arterial disease incidence in middle-aged adults: the Atherosclerosis Risk in Communities (ARIC) Study
Background: Peripheral arterial disease (PAD) is a costly source of morbidity and mortality among older persons in the United States. Dietary intake plays a role in the development of atherosclerotic cardiovascular disease; however, few studies have examined the relation of food intake or dietary patterns with PAD
Inpatient and Outpatient Infection as a Trigger of Cardiovascular Disease: The ARIC Study
Background
Acute infections are known cardiovascular disease (CVD) triggers, but little is known regarding how CVD risk varies following inpatient versus outpatient infections. We hypothesized that in‐ and outpatient infections are associated with CVD risk and that the association is stronger for inpatient infections. Methods and Results
Coronary heart disease (CHD) and ischemic stroke cases were identified and adjudicated in the ARIC (Atherosclerosis Risk in Communities Study). Hospital discharge diagnosis codes and Medicare claims data were used to identify infections diagnosed in in‐ and outpatient settings. A case‐crossover design and conditional logistic regression were used to compare in‐ and outpatient infections among CHD and ischemic stroke cases (14, 30, 42, and 90 days before the event) with corresponding control periods 1 and 2 years previously. A total of 1312 incident CHD cases and 727 incident stroke cases were analyzed. Inpatient infections (14‐day odds ratio [OR]=12.83 [5.74, 28.68], 30‐day OR=8.39 [4.92, 14.31], 42‐day OR=6.24 [4.02, 9.67], and 90‐day OR=4.48 [3.18, 6.33]) and outpatient infections (14‐day OR=3.29 [2.50, 4.32], 30‐day OR=2.69 [2.14, 3.37], 42‐day OR=2.45 [1.97, 3.05], and 90‐day OR=1.99 [1.64, 2.42]) were more common in all CHD case periods compared with control periods and inpatient infection was a stronger CHD trigger for all time periods (P Conclusions
In‐ and outpatient infections are associated with CVD risk. Patients with an inpatient infection may be at particularly elevated CVD risk and should be considered potential candidates for CVD prophylaxis
Inpatient versus outpatient acute venous thromboembolism management: Trends and postacute healthcare utilization from 2011 to 2018
Background - Acute outpatient management of venous thromboembolism (VTE), which includes pulmonary embolism (PE) and deep vein thrombosis (DVT), is perceived to be as safe as inpatient management in some settings. How widely this strategy is used is not well documented.
Methods and Results - Using MarketScan administrative claims databases for years 2011 through 2018, we identified patients with International Classification of Diseases (ICD) codes indicating incident VTE and trends in the use of acute outpatient management. We also evaluated healthcare utilization and hospitalized bleeding events in the 6 months following the incident VTE event. A total of 200 346 patients with VTE were included, of whom 50% had evidence of PE. Acute outpatient management was used for 18% of those with PE and 57% of those with DVT only, and for both DVT and PE its use increased from 2011 to 2018. Outpatient management was less prevalent among patients with cancer, higher Charlson comorbidity index scores, and whose primary treatment was warfarin as compared with a direct oral anticoagulant. Healthcare utilization in the 6 months following the incident VTE event was generally lower among patients managed acutely as outpatients, regardless of initial presentation. Acute outpatient management was associated with lower hazard ratios of incident bleeding risk for both patients who initially presented with PE (0.71 [95% CI, 0.61, 0.82]) and DVT only (0.59 [95% CI, 0.54, 0.64]).
Conclusions - Outpatient management of VTE is increasing. In the present analysis, it was associated with lower subsequent healthcare utilization and fewer bleeding events. However, this may be because healthier patients were managed on an outpatient basis
Racial/Ethnic Differences in Sleep Disturbances: The Multi-Ethnic Study of Atherosclerosis (MESA)
Objectives:
There is limited research on racial/ethnic variation in sleep disturbances. This study aimed to quantify the distributions of objectively
measured sleep disordered breathing (SDB), short sleep duration, poor sleep quality, and self-reported sleep disturbances (e.g., insomnia) across
racial/ethnic groups.
Design: Cross-sectional study.
Setting: Six US communities.
Participants: Racially/ethnically diverse men and women aged 54–93 y in the Multi-Ethnic Study of Atherosclerosis Sleep Cohort (n = 2,230).
Interventions: N/A.
Measurements and Results: Information from polysomnography-measured SDB, actigraphy-measured sleep duration and quality, and selfreported
daytime sleepiness were obtained between 2010 and 2013. Overall, 15.0% of individuals had severe SDB (apnea-hypopnea index [AHI]
≥ 30); 30.9% short sleep duration (< 6 h); 6.5% poor sleep quality (sleep efficiency <85%); and 13.9% had daytime sleepiness. Compared with
Whites, Blacks had higher odds of sleep apnea syndrome (AHI ≥ 5 plus sleepiness) (sex-, age-, and study site-adjusted odds ratio [OR] = 1.78,
95% confidence interval [CI]: 1.20, 2.63), short sleep (OR = 4.95, 95% CI: 3.56, 6.90), poor sleep quality (OR = 1.57, 95% CI: 1.00, 2.48), and
daytime sleepiness (OR = 1.89, 95% CI: 1.38, 2.60). Hispanics and Chinese had higher odds of SDB and short sleep than Whites. Among nonobese
individuals, Chinese had the highest odds of SDB compared to Whites. Only 7.4% to 16.2% of individuals with an AHI ≥ 15 reported a prior
diagnosis of sleep apnea.
Conclusions: Sleep disturbances are prevalent among middle-aged and older adults, and vary by race/ethnicity, sex, and obesity status. The
high prevalence of sleep disturbances and undiagnosed sleep apnea among racial/ethnic minorities may contribute to health disparities.
Keywords: apnea-hypopnea index, body mass index, daytime sleepiness, obesity, polysomnography, race/ethnicity, sleep disordered breathing,
sleep disturbance, sleep duration, sleep qualit
Autoimmune disease and risk of postpartum venous thromboembolism
Background - The risk of pregnancy-related mortality in the United States has nearly doubled since 1990, with venous thromboembolism (VTE) accounting for approximately 10% of these deaths.
Objectives - The objective of this study was to assess whether preexisting autoimmune disease is a risk factor for postpartum VTE.
Methods - Using the MarketScan Commercial and Medicare Supplemental administrative databases, a retrospective cohort study analyzed whether postpartum persons with autoimmune disease had a higher risk of postpartum VTE incidence than postpartum persons without autoimmune disease. Using International Classification of Diseases codes, we identified 757,303 individuals of childbearing age who had a valid delivery date with at least 12 weeks of follow-up.
Results - Individuals were, on average, 30.7 years old (SD, 5.4), and 3.7% (N = 27,997 of 757,303) of them had evidence of preexisting autoimmune disease. In covariate-adjusted models, postpartum persons with preexisting autoimmune disease had higher rates of postpartum VTE than postpartum persons without autoimmune disease (hazard ratio [HR], 1.33; 95% CI, 1.07-1.64). When analyzed by individual autoimmune disease, those with systemic lupus erythematosus (HR, 2.49; 95% CI, 1.47-4.21) and Crohn’s disease (HR, 2.49; 95% CI, 1.34-4.64) were at an elevated risk of postpartum VTE compared with those without autoimmune disease.
Conclusion - Autoimmune disease was associated with a higher rate of postpartum VTE, with evidence that the association was most pronounced among individuals with systemic lupus erythematosus and Crohn’s disease. These findings suggest that postpartum persons of childbearing age with autoimmune disease may require more monitoring and prophylactic care after delivery to prevent potentially fatal VTE events
Obstructive Sleep Apnea and 15-Year Cognitive Decline: The Atherosclerosis Risk in Communities (ARIC) Study
Prospective data evaluating abnormal sleep quality and quantity with cognitive decline are limited because most studies used subjective data and/or had short follow-up. We hypothesized that, over 15 y of follow-up, participants with objectively measured obstructive sleep apnea (OSA) and other indices of poor sleep quantity and quality would experience greater decline in cognitive functioning than participants with normal sleep patterns
Weight change over 9 years and subsequent risk of venous thromboembolism in the ARIC cohort
Background/objectives: Weight gain increases risk of cardiovascular disease, but has not been examined extensively in relationship to venous thromboembolism (VTE). The association between weight change over 9 years and subsequent VTE among participants in the Atherosclerosis Risk in Communities (ARIC) study was examined, with a hypothesis that excess weight gain is a risk factor for VTE, relative to no weight change. Subjects/methods: Quintiles of 9-year weight change were calculated (visit 4 1996–1998 weight minus visit 1 1987–1989 weight in kg: Quintile 1: ≥−1.81 kg; Quintile 2: 1.36 to ≤4.08 kg; Quintile 4: >4.08 to ≤7.71 kg; Quintile 5: >7.71 kg). Incident VTEs from visit 4 (1996–1998) through 2015 were identified and adjudicated using medical records. Hazard ratios (HRs) were calculated using Cox models. Results: 529 incident VTEs were identified during an average of 19 years of follow up. Compared to Quintile 2, participants in Quintile 5 of weight change had 1.46 times the rate of incident VTE (HR = 1.46 (95% CI 1.09, 1.95), adjusted for age, race, sex, income, physical activity, smoking, and prevalent CVD). The HR for Quintile 5 was modestly attenuated to 1.38 (95% CI 1.03, 1.84) when visit 1 BMI was included in the model. When examined separately, results were significant for unprovoked VTE, but not for provoked VTE. Among those obese at visit 1, both weight gain (HR 1.86 95% CI 1.27, 2.71) and weight loss (HR 2.11 95% CI 1.39, 3.19) were associated with incident VTE, compared with normal-weight participants with no weight change. Conclusions: Weight gain later life was associated with increased risk for unprovoked VTE. Among those with obesity, both weight gain and weight loss were associated with increased risk for VTE
- …