@article {1445, title = {Epidemiology of low cholesterol levels in older adults. The Cardiovascular Health Study.}, journal = {Circulation}, volume = {87}, year = {1993}, month = {1993 Mar}, pages = {728-37}, abstract = {

BACKGROUND: Low cholesterol levels have been associated with increased mortality from stroke, cancer, and other noncardiovascular diseases, but the reasons for this association remain unclear. One explanation is that persons with low cholesterol levels have early or occult disease that eventually leads to their deaths.

METHODS AND RESULTS: This possibility was explored in 2,091 men and 2,714 women 65-100 years old in the Cardiovascular Health Study, a multicenter observational study of risk factors for heart disease and stroke in older adults. Cholesterol levels < or = 160 mg/dL were present in 11.6\% of men and 3.7\% of women and increased in prevalence with age. After adjustment for age, total cholesterol levels in this range were associated with a twofold increased prevalence of treated diabetes in men and women and with a twofold increased prevalence of cancer diagnosed in the preceding 5 years in women only. Low cholesterol was also associated with lower levels of hemoglobin, albumin, and factor VII, suggesting a link with hepatic synthetic function. On multivariate analysis, factors most strongly associated with low cholesterol levels in men and women were decreased factor VII levels, decreased albumin, and diabetes.

CONCLUSIONS: Cross-sectional associations with low cholesterol levels differ by sex and suggest poorer health by some measures. The observed relations with treated diabetes and impaired hepatic synthetic function should be examined for risk of mortality in longitudinal data from this and other observational studies.

}, keywords = {Aged, Aged, 80 and over, Aging, Cardiovascular Diseases, Cardiovascular Physiological Phenomena, Cholesterol, Female, Health Status, Humans, Longitudinal Studies, Male, Prevalence, Probability, Regression Analysis, Risk Factors}, issn = {0009-7322}, author = {Manolio, T A and Ettinger, W H and Tracy, R P and Kuller, L H and Borhani, N O and Lynch, J C and Fried, L P} } @article {1500, title = {Predicting future years of healthy life for older adults.}, journal = {J Clin Epidemiol}, volume = {51}, year = {1998}, month = {1998 Apr}, pages = {343-53}, abstract = {

Cost-effectiveness studies often need to compare the cost of a program to the lifetime benefits of the program, but estimates of lifetime benefits are not routinely available, especially for older adults. We used data from two large longitudinal studies of older adults (ages 65-100) to estimate transition probabilities from one health state to another, and used those probabilities to estimate the mean additional years of healthy life that an older adult of specified age, sex, and health status would experience. We found, for example, that 65-year-old women in excellent health can expect 16.8 years of healthy life in the future, compared to only 8.5 years for women in poor health. We also provide estimates of discounted years of healthy life and future life expectancy. These estimates may be used to extend the effective length of the study period in cost-effectiveness studies, to examine the impact of chronic diseases or risk factors on years of healthy life, or to investigate the relationship of years of life to years of healthy life. Several applications are described.

}, keywords = {Aged, Aged, 80 and over, Cost-Benefit Analysis, Female, Forecasting, Health Promotion, Health Status, Humans, Life Expectancy, Life Tables, Male, Probability, Quality-Adjusted Life Years, Sex Factors}, issn = {0895-4356}, author = {Diehr, P and Patrick, D L and Bild, D E and Burke, G L and Williamson, J D} } @article {646, title = {Factors associated with healthy aging: the cardiovascular health study.}, journal = {J Am Geriatr Soc}, volume = {49}, year = {2001}, month = {2001 Mar}, pages = {254-62}, abstract = {

OBJECTIVES: To identify factors associated with remaining healthy in older adults.

DESIGN: Longitudinal cohort study.

SETTING: Data were collected at the four Cardiovascular Health Study field centers.

PARTICIPANTS: 5,888 participants age 65 years and older in the Cardiovascular Health Study.

MEASUREMENTS: Presence of chronic disease was assessed at baseline and over a maximum 7-year follow-up period. Participants who were free of chronic disease (no cardiovascular disease (CVD), chronic obstructive pulmonary disease, or self-reported cancer, except nonmelanoma skin cancer) at the baseline examination were then monitored for the onset of incident cancer, cardiovascular disease, and fatal outcomes.

RESULTS: A high proportion of these older adults was healthy at the initial examination and remained healthy over the follow-up period. Numerous behavioral factors were associated with continued health, including physical activity, refraining from cigarette smoking, wine consumption (women), higher educational status, and lower waist circumference. A number of CVD risk factors and subclinical disease measures were associated with continued health, including higher high-density lipoprotein (HDL) cholesterol, lack of diabetes, thinner common carotid intimal nmedial thickness, lower blood pressure, lower C-reactive protein, and higher ankle-arm blood pressure ratio. Among the behavioral factors, exercise, not smoking, and not taking aspirin remained significant predictors of health even after controlling for CVD risk factors and subclinical disease in older adults.

CONCLUSIONS: These data suggest that a number of modifiable behavioral factors (physical activity, smoking, and obesity) and cardiovascular risk factors (diabetes, HDL cholesterol, and blood pressure) are associated with maintenance of good health in older adults.

}, keywords = {Aged, Aged, 80 and over, Aging, Cardiovascular Diseases, Cohort Studies, Diet, Exercise, Female, Health Status, Humans, Incidence, Life Style, Longitudinal Studies, Lung Diseases, Obstructive, Male, Neoplasms, Probability, Reference Values, Risk Factors, Sex Distribution, Socioeconomic Factors, Survival Rate, United States}, issn = {0002-8614}, doi = {10.1046/j.1532-5415.2001.4930254.x}, author = {Burke, G L and Arnold, A M and Bild, D E and Cushman, M and Fried, L P and Newman, A and Nunn, C and Robbins, J} } @article {673, title = {Probabilities of transition among health states for older adults.}, journal = {Qual Life Res}, volume = {10}, year = {2001}, month = {2001}, pages = {431-42}, abstract = {

GOAL: To estimate the probabilities of transition among self-rated health states for older adults, and examine how they vary by age and sex.

METHODS: We used self-rated health (excellent, very good, good, fair, poor, dead) collected in two longitudinal studies of older adults (mean age 75) to estimate the probability of transition in 2 years. We used the estimates to project future health for selected cohorts.

FINDINGS: These older adults were most likely to be in the same health state 2 years later, but a substantial proportion changed in both directions. Transition probabilities varied by initial health state, age and sex. Men were more likely than women to transition to excellent or dead. Women were more likely than men to transition to good or fair health. Although women aged 70 will have more years of life and more years of healthy life than men, they also have more years of unhealthy life, and the proportion of remaining life that is healthy is slightly higher for men. When observed and predicted years of healthy life (YHL) were compared in various subgroups, the YHL of persons with less favorable baseline characteristics was lower than predicted, and vice-versa. Differences, however, were small (about 5\%).

CONCLUSIONS: These transition probability estimates can be used to predict the future health of individuals or groups as a function of current age, sex, and self-rated health.

}, keywords = {Age Factors, Aged, Aging, Female, Health Status, Humans, Male, Probability, Quality of Life, Regression Analysis, Sex Factors}, issn = {0962-9343}, doi = {10.1023/a:1012566130639}, author = {Diehr, P and Patrick, D L} } @article {786, title = {Alcohol consumption and inflammatory markers in older adults: the Cardiovascular Health Study.}, journal = {Atherosclerosis}, volume = {173}, year = {2004}, month = {2004 Mar}, pages = {79-87}, abstract = {

OBJECTIVE: We sought to determine the relation of alcohol intake and systemic inflammation in a population-based sample of older adults.

METHODS AND RESULTS: As part of the Cardiovascular Health Study (CHS), 5865 adults aged 65 years and older reported their intake of beer, wine, and liquor. We determined white blood cell count (WBC), factor VIII coagulant activity (factor VIIIc), and levels of C-reactive protein (CRP), fibrinogen, and albumin as markers of systemic inflammation. Among participants without confirmed cardiovascular disease, alcohol consumption was inversely associated with WBC, factor VIIIc, and fibrinogen level, and positively associated with albumin concentration in multivariate analyses. We found no consistent modification of these results by sex, obesity, or beverage type. The relation of alcohol use and CRP levels was significantly modified by apoE genotype (P interaction 0.03), with a positive association among participants with an apoE4 allele (P = 0.05), but a trend toward an inverse association among those without an apoE4 allele (P = 0.15).

CONCLUSIONS: Alcohol intake is associated with lower levels of inflammatory markers in older adults free of cardiovascular disease.

}, keywords = {Aged, Aged, 80 and over, Alcohol Drinking, Apolipoproteins E, C-Reactive Protein, Coronary Artery Disease, Female, Fibrinogen, Geriatric Assessment, Humans, Inflammation Mediators, Leukocyte Count, Logistic Models, Longitudinal Studies, Male, Probability, Prospective Studies, Risk Assessment, Sensitivity and Specificity, Severity of Illness Index}, issn = {0021-9150}, doi = {10.1016/j.atherosclerosis.2003.10.011}, author = {Mukamal, Kenneth J and Cushman, Mary and Mittleman, Murray A and Tracy, Russell P and Siscovick, David S} } @article {752, title = {Sleep apnea and markers of vascular endothelial function in a large community sample of older adults.}, journal = {Am J Respir Crit Care Med}, volume = {169}, year = {2004}, month = {2004 Feb 01}, pages = {354-60}, abstract = {

Clinical studies have suggested that sleep apnea is associated with impaired brachial artery flow-mediated dilation, a surrogate of endothelial dysfunction. We examined this question among older participants in the baseline examination of the Sleep Heart Health/Cardiovascular Health Study cohort (n = 1,037, age 68 years or older, 56\% female). Indices of sleep apnea, derived from 12-channel home polysomnography, were the apnea-hypopnea index (average number of apneas/hypopneas per hour) and the hypoxemia index (percentage of time below 90\% O2 saturation). Baseline arterial diameter and percentage of flow-mediated dilation were measured by ultrasound. Sleep apnea measures were associated with baseline diameter and the percentage of flow-mediated dilation, although these associations were weakened after adjustment for other cardiovascular risk factors, particularly body mass index. However, a statistically significant linear association between the hypoxemia index and baseline diameter was observed even after adjustment for body mass index and other confounders (p < 0.01). The associations were stronger among participants who were younger than 80 years and among those who with hypertension. This study adds to the growing body of evidence linking sleep apnea with vascular dysfunction in older subjects. Whether these relationships are entirely independent of obesity is unclear. This association might be one of the mechanisms explaining the relationship between sleep apnea, hypertension, and cardiovascular disease.

}, keywords = {Age Factors, Aged, Aged, 80 and over, Biomarkers, Body Mass Index, Brachial Artery, Cardiovascular Diseases, Cohort Studies, Comorbidity, Endothelium, Vascular, Female, Humans, Hypertension, Linear Models, Male, Polysomnography, Prevalence, Probability, Residence Characteristics, Risk Assessment, Sampling Studies, Severity of Illness Index, Sleep Apnea Syndromes, Ultrasonography, Doppler}, issn = {1073-449X}, doi = {10.1164/rccm.200306-756OC}, author = {Nieto, F Javier and Herrington, David M and Redline, Susan and Benjamin, Emelia J and Robbins, John A} } @article {818, title = {Fish consumption and stroke risk in elderly individuals: the cardiovascular health study.}, journal = {Arch Intern Med}, volume = {165}, year = {2005}, month = {2005 Jan 24}, pages = {200-6}, abstract = {

BACKGROUND: Associations between fish consumption and stroke risk have been inconsistent, possibly because of the differences in types of fish meals consumed. Additionally, such relationships have not been specifically evaluated in the elderly, in whom disease burden may be high and diet less influential.

METHODS: Among 4775 adults 65 years or older (range, 65-98 years) and free of known cerebrovascular disease at baseline in 1989-1990, usual dietary intake was assessed using a food frequency questionnaire. In a subset, consumption of tuna or other broiled or baked fish, but not fried fish or fish sandwiches (fish burgers), correlated with plasma phospholipid long-chain n-3 fatty acid levels. Incident strokes were prospectively ascertained.

RESULTS: During 12 years of follow-up, participants experienced 626 incident strokes, including 529 ischemic strokes. In multivariate analyses, tuna/other fish consumption was inversely associated with total stroke (P = .04) and ischemic stroke (P = .02), with 27\% lower risk of ischemic stroke with an intake of 1 to 4 times per week (hazard ratio [HR], 0.73; 95\% confidence interval [CI], 0.55-0.98) and 30\% lower risk with intake of 5 or more times per week (HR, 0.70; 95\% CI, 0.50-0.99) compared with an intake of less than once per month. In contrast, fried fish/fish sandwich consumption was positively associated with total stroke (P = .006) and ischemic stroke (P = .003), with a 44\% higher risk of ischemic stroke with consumption of more than once per week (HR, 1.44; 95\% CI, 1.12-1.85) compared with consumption of less than once per month. Fish consumption was not associated with hemorrhagic stroke.

CONCLUSIONS: Among elderly individuals, consumption of tuna or other broiled or baked fish is associated with lower risk of ischemic stroke, while intake of fried fish or fish sandwiches is associated with higher risk. These results suggest that fish consumption may influence stroke risk late in life; potential mechanisms and alternate explanations warrant further study.

}, keywords = {Age Distribution, Aged, Aged, 80 and over, Animals, Cohort Studies, Confidence Intervals, Diet, Fatty Acids, Omega-3, Female, Fish Oils, Fishes, Humans, Incidence, Male, Multivariate Analysis, Probability, Proportional Hazards Models, Risk Assessment, Seafood, Sensitivity and Specificity, Sex Distribution, Stroke, Surveys and Questionnaires, Survival Rate, United States}, issn = {0003-9926}, doi = {10.1001/archinte.165.2.200}, author = {Mozaffarian, Dariush and Longstreth, W T and Lemaitre, Rozenn N and Manolio, Teri A and Kuller, Lewis H and Burke, Gregory L and Siscovick, David S} } @article {865, title = {Kidney function as a predictor of noncardiovascular mortality.}, journal = {J Am Soc Nephrol}, volume = {16}, year = {2005}, month = {2005 Dec}, pages = {3728-35}, abstract = {

Chronic kidney disease is associated with a higher risk for cardiovascular mortality, as well as all-cause mortality. Whether chronic kidney disease is a predictor of noncardiovascular mortality is less clear. To further explore the latter, the association of kidney function with total noncardiovascular mortality and cause-specific mortality was assessed in the Cardiovascular Health Study, a community-based cohort of older individuals. Kidney disease was assessed using cystatin C and estimated GFR in 4637 participants in 1992 to 1993. Participants were followed until June 30, 2001. Deaths were adjudicated as cardiovascular or noncardiovascular disease by committee, and an underlying cause of death was assigned. The associations of kidney function with total noncardiovascular mortality and cause-specific mortality were analyzed by proportional hazards regression. Noncardiovascular mortality rates increased with higher cystatin C quartiles (16.8, 17.1, 21.6, and 50.0 per 1000 person-years). The association of cystatin C with noncardiovascular mortality persisted after adjustment for demographic factors; the presence of diabetes, C-reactive protein, hemoglobin, and prevalent cardiovascular disease; and measures of atherosclerosis (hazard ratio 1.69; 95\% confidence interval 1.33 to 2.15, for the fourth quartile versus the first quartile). Results for estimated GFR were similar. The risk for noncardiac deaths attributed to pulmonary disease, infection, cancer, and other causes was similarly associated with cystatin C levels. Kidney function predicts noncardiovascular mortality from multiple causes in the elderly. Further research is needed to understand the mechanisms and evaluate interventions to reduce the high mortality rate in chronic kidney disease.

}, keywords = {Age Factors, Aged, Aged, 80 and over, Cardiovascular Diseases, Cause of Death, Cohort Studies, Confidence Intervals, Creatinine, Cystatin C, Cystatins, Female, Glomerular Filtration Rate, Humans, Kidney Failure, Chronic, Kidney Function Tests, Longitudinal Studies, Male, Probability, Proportional Hazards Models, Risk Assessment, Severity of Illness Index, Survival Analysis, United States}, issn = {1046-6673}, doi = {10.1681/ASN.2005040384}, author = {Fried, Linda F and Katz, Ronit and Sarnak, Mark J and Shlipak, Michael G and Chaves, Paulo H M and Jenny, Nancy Swords and Stehman-Breen, Catherine and Gillen, Dan and Bleyer, Anthony J and Hirsch, Calvin and Siscovick, David and Newman, Anne B} } @article {819, title = {Renovascular disease and the risk of adverse coronary events in the elderly: a prospective, population-based study.}, journal = {Arch Intern Med}, volume = {165}, year = {2005}, month = {2005 Jan 24}, pages = {207-13}, abstract = {

BACKGROUND: Renovascular disease is a cause of secondary hypertension and renal insufficiency and is suspected to contribute to morbidity and mortality of coronary heart disease. This investigation prospectively examined associations between renovascular disease and adverse coronary events among a population-based sample of elderly Americans.

METHODS: The Cardiovascular Health Study is a prospective, multicenter cohort study of cardiovascular disease risk factors, morbidity, and mortality among Americans older than 65 years. Renal duplex sonography was performed on 870 individuals between January 1995 and February 1997. Renovascular disease was defined as any focal peak systolic velocity of 1.8 m/s or greater (renal artery stenosis) or the absence of a Doppler-shifted signal from an imaged artery (renal artery occlusion). Adverse coronary events were defined as hospitalized angina, fatal or nonfatal myocardial infarction, and coronary revascularization.

RESULTS: During a mean follow-up of 14 months, 68 participants experienced incident or recurrent adverse coronary events. The presence of renovascular disease demonstrated a significant relationship with adverse coronary events (hazard ratio, 1.96; 95\% confidence interval, 1.00-3.83; P = .05) that remained after controlling for the effects of coexisting atherosclerotic risk factors and prevalent cardiovascular disease. The relationship between renovascular disease and adverse coronary events was not dependent on the effects of increased blood pressure.

CONCLUSIONS: The presence of renovascular disease was associated with an increase in the risk of adverse coronary events in this sample. The increment in risk was not dependent on the effects of associated atherosclerotic risk factors, other prevalent cardiovascular disease, or increased blood pressure.

}, keywords = {Age Distribution, Aged, Aged, 80 and over, Analysis of Variance, Cohort Studies, Comorbidity, Coronary Disease, Female, Geriatric Assessment, Heart Function Tests, Humans, Hypertension, Renovascular, Incidence, Kidney Function Tests, Male, Multivariate Analysis, Probability, Prognosis, Prospective Studies, Risk Assessment, Severity of Illness Index, Sex Distribution, Survival Rate, Ultrasonography, Doppler, United States}, issn = {0003-9926}, doi = {10.1001/archinte.165.2.207}, author = {Edwards, Matthew S and Craven, Timothy E and Burke, Gregory L and Dean, Richard H and Hansen, Kimberley J} } @article {981, title = {Age-specific prevalence and years of healthy life in a system with three health states.}, journal = {Stat Med}, volume = {27}, year = {2008}, month = {2008 Apr 30}, pages = {1371-86}, abstract = {

Consider a 3-state system with one absorbing state, such as Healthy, Sick, and Dead. Over time, the prevalence of the Healthy state will approach an {\textquoteright}equilibrium{\textquoteright} value that is independent of the initial conditions. We derived this equilibrium prevalence (Prev:Equil) as a function of the local transition probabilities. We then used Prev:Equil to estimate the expected number of years spent in the healthy state over time. This estimate is similar to the one calculated by multi-state life table methods, and has the advantage of having an associated standard error. In longitudinal data for older adults, the standard error was accurate when a valid survival table was known from other sources, or when the available data set was sufficient to estimate survival accurately. Performance was better with fewer waves of data. If validated in other situations, these estimates of prevalence and years of healthy life (YHL) and their standard errors may be useful when the goal is to compare YHL for different populations.

}, keywords = {Age Factors, Biometry, Health Status, Humans, Life Tables, Longitudinal Studies, Middle Aged, Models, Statistical, Probability, Quality-Adjusted Life Years}, issn = {0277-6715}, doi = {10.1002/sim.3056}, author = {Diehr, Paula and Yanez, David and Derleth, Ann and Newman, Anne B} } @article {1012, title = {Cystatin C concentration as a predictor of systolic and diastolic heart failure.}, journal = {J Card Fail}, volume = {14}, year = {2008}, month = {2008 Feb}, pages = {19-26}, abstract = {

BACKGROUND: Risk factors for heart failure (HF) may differ according to ejection fraction (EF). Higher cystatin C, a marker of kidney dysfunction, is associated with incident HF, but previous studies did not determine EF at diagnosis. We hypothesized that kidney dysfunction would predict diastolic HF (DHF) better than systolic HF (SHF) in the Cardiovascular Health Study.

METHODS AND RESULTS: Cystatin C was measured in 4453 participants without HF at baseline. Incident HF was categorized as DHF (EF > or = 50\%) or SHF (EF < 50\%). We compared the association of cystatin C with the risk for DHF and SHF, after adjustment for age, sex, race, medications, and HF risk factors. During 8 years of follow-up, 167 participants developed DHF and 206 participants developed SHF. After adjustment, sequentially higher quartiles of cystatin C were associated with risk for SHF (competing risks hazard ratios 1.0 [reference], 1.99 [95\% confidence interval 1.14-3.48], 2.32 [1.32-4.07], 3.17 [1.82-5.50], P for trend < .001). The risk for DHF was apparent only at the highest cystatin C quartile (hazard ratios 1.0 [reference], 1.09 [0.62-1.89], 1.08 [0.61-1.93], and 1.83 [1.07-3.11]).

CONCLUSIONS: Cystatin C levels are linearly associated with the incidence of systolic HF, whereas only the highest concentrations of cystatin C predict diastolic HF.

}, keywords = {Aged, Aged, 80 and over, Biomarkers, Cohort Studies, Confidence Intervals, Cystatin C, Cystatins, Echocardiography, Female, Heart Failure, Diastolic, Heart Failure, Systolic, Humans, Longitudinal Studies, Male, Predictive Value of Tests, Probability, Proportional Hazards Models, Risk Assessment, Sensitivity and Specificity, Stroke Volume, Survival Analysis}, issn = {1532-8414}, doi = {10.1016/j.cardfail.2007.09.002}, author = {Moran, Andrew and Katz, Ronit and Smith, Nicolas L and Fried, Linda F and Sarnak, Mark J and Seliger, Stephen L and Psaty, Bruce and Siscovick, David S and Gottdiener, John S and Shlipak, Michael G} } @article {1124, title = {Total and cause-specific mortality in the cardiovascular health study.}, journal = {J Gerontol A Biol Sci Med Sci}, volume = {64}, year = {2009}, month = {2009 Dec}, pages = {1251-61}, abstract = {

BACKGROUND: Few cohort studies have adequate numbers of carefully reviewed deaths to allow an analysis of unique and shared risk factors for cause-specific mortality. Shared risk factors could be targeted for prevention of premature death and the study of longevity.

METHODS: A total of 5,888 community-dwelling persons aged 65 years or older living in four communities in the United States participated in the Cardiovascular Health Study cohort. Participants were initially recruited from 1989 to 1990; an additional 687 black participants were recruited in 1992-1993. The average length of follow-up was 16 years. Total and cause-specific mortality, including cardiovascular disease, stroke, cancer, dementia, pulmonary disease, infection, and other cause, were examined as outcomes. Variables previously associated with total mortality were examined for each cause of death using Cox proportional hazard models.

RESULTS: Multiple risk factors were related to total mortality. When examining specific causes, many factors were related to cardiovascular death, whereas fewer were related to other causes. For most causes, risk factors were specific for that cause. For example, apolipoprotein E epsilon4 was strongly associated for dementia death and forced vital capacity with pulmonary death. Age, male sex, markers of inflammation, and cognitive function were related to multiple causes of death.

CONCLUSIONS: In these older adults, associations of risk factors with a given cause of death were related to specific deficits in that same organ system. Inflammation may represent a common pathway to all causes of death.

}, keywords = {Age Factors, Aged, Aged, 80 and over, Aging, Cardiovascular Diseases, Cause of Death, Chronic Disease, Cohort Studies, Female, Geriatric Assessment, Health Surveys, Humans, Kaplan-Meier Estimate, Male, Probability, Proportional Hazards Models, Retrospective Studies, Risk Assessment, Severity of Illness Index, Sex Factors, Survival Analysis, United States}, issn = {1758-535X}, doi = {10.1093/gerona/glp127}, author = {Newman, Anne B and Sachs, Michael C and Arnold, Alice M and Fried, Linda P and Kronmal, Richard and Cushman, Mary and Psaty, Bruce M and Harris, Tamara B and Robbins, John A and Burke, Gregory L and Kuller, Lewis H and Lumley, Thomas} } @article {1096, title = {Usefulness of myeloperoxidase levels in healthy elderly subjects to predict risk of developing heart failure.}, journal = {Am J Cardiol}, volume = {103}, year = {2009}, month = {2009 May 01}, pages = {1269-74}, abstract = {

Increased systemic myeloperoxidase (MPO) has been associated with both the presence and severity of heart failure (HF). This study tested the hypothesis that increased systemic MPO in apparently healthy elderly subjects may predict increased risk of developing HF. Systemic MPO was measured in all available samples from the 1992 to 1993 visit of the Cardiovascular Health Study (CHS). After excluding subjects without available blood samples or with a history of prevalent HF, myocardial infarction (MI), or stroke, 3,733 subjects were included. A total of 569 subjects developed incident HF during 7.2 +/- 2.3 years of follow-up. Patients in the highest MPO quartile (>432 pmol/L) showed higher risk of developing incident HF after adjusting for MI, age, gender, systolic blood pressure, smoking, low-density lipoprotein cholesterol, diabetes mellitus, and any subclinical cardiovascular disease (hazard ratio 1.34, 95\% confidence interval 1.06 to 1.72, p = 0.013). However, the relation was more apparent after censoring subjects with incident MI before incident HF, even when adjusted for C-reactive protein and cystatin C (hazard ratio 1.46, 95\% confidence interval 1.08 to 1.97, p = 0.02). Interestingly, stratified analyses showed that the relation between increased MPO and HF risk was stronger in subjects without traditional cardiovascular risk factors (}, keywords = {Age Factors, Aged, Aged, 80 and over, Biomarkers, Disease Progression, Female, Geriatric Assessment, Heart Failure, Humans, Longitudinal Studies, Male, Peroxidase, Predictive Value of Tests, Probability, Prognosis, Risk Assessment, Sensitivity and Specificity, Severity of Illness Index, Sex Factors}, issn = {1879-1913}, doi = {10.1016/j.amjcard.2009.01.026}, author = {Tang, W H Wilson and Katz, Ronit and Brennan, Marie-Luise and Aviles, Ronnier J and Tracy, Russell P and Psaty, Bruce M and Hazen, Stanley L} } @article {1542, title = {Probabilistic sleep architecture models in patients with and without sleep apnea.}, journal = {J Sleep Res}, volume = {21}, year = {2012}, month = {2012 Jun}, pages = {330-41}, abstract = {

Sleep fragmentation of any cause is disruptive to the rejuvenating value of sleep. However, methods to quantify sleep architecture remain limited. We have previously shown that human sleep-wake stage distributions exhibit multi-exponential dynamics, which are fragmented by obstructive sleep apnea (OSA), suggesting that Markov models may be a useful method to quantify architecture in health and disease. Sleep stage data were obtained from two subsets of the Sleep Heart Health Study database: control subjects with no medications, no OSA, no medical co-morbidities and no sleepiness (n = 374); and subjects with severe OSA (n = 338). Sleep architecture was simplified into three stages: wake after sleep onset (WASO); non-rapid eye movement (NREM) sleep; and rapid eye movement (REM) sleep. The connectivity and transition rates among eight {\textquoteright}generator{\textquoteright} states of a first-order continuous-time Markov model were inferred from the observed ({\textquoteright}phenotypic{\textquoteright}) distributions: three exponentials each of NREM sleep and WASO; and two exponentials of REM sleep. Ultradian REM cycling was accomplished by imposing time-variation to REM state entry rates. Fragmentation in subjects with severe OSA involved faster transition probabilities as well as additional state transition paths within the model. The Markov models exhibit two important features of human sleep architecture: multi-exponential stage dynamics (accounting for observed bout distributions); and probabilistic transitions (an inherent source of variability). In addition, the model quantifies the fragmentation associated with severe OSA. Markov sleep models may prove important for quantifying sleep disruption to provide objective metrics to correlate with endpoints ranging from sleepiness to cardiovascular morbidity.

}, keywords = {Cohort Studies, Computer Simulation, Humans, Models, Theoretical, Polysomnography, Probability, Sleep Apnea Syndromes, Sleep Stages, Sleep, REM, Time Factors}, issn = {1365-2869}, doi = {10.1111/j.1365-2869.2011.00937.x}, author = {Bianchi, Matt T and Eiseman, Nathaniel A and Cash, Sydney S and Mietus, Joseph and Peng, Chung-Kang and Thomas, Robert J} }