Isotope Dilution Space Ratio Declines Above the Age of 60 Y, Potentially Impacting Estimates of Total Energy Expenditure by the Doubly Labeled Water Method.

Doubly labeled water is gold standard for measuring total energy expenditure (TEE). Measurements using the method are sensitive to the isotope dilution space ratio (DSR). Accuracy and precision of the method might be improved if we could identify factors influencing DSR. We evaluated the potential associations of age, sex, ethnicity, anthropometry, body composition, turnover rates of the isotopes, and geographical elevation with DSR. We used univariate regression analysis to explore the relationships between the continuous variables and analysis of variance to test the relationships between the categorical variables with DSR. Subsequently, we used general linear model (GLM) and 1-way analysis of variance to evaluate the simultaneous associations of age, sex, ethnicity, fat-free mass (FFM) and fat mass (FM) on DSR. From 5678 measurements complied from studies around the world with diverse ethnicity and living at various elevations, the mean DSR was 1.0364 ± 0.0141. No meaningful physiologic effect of any of the continuous and categorical variable on DSR was detected. General linear model analysis revealed no effect of FFM and FM (P > 0.33) on DSR, but DSR decreased with age (P < 0.001) among those aged 60 y and older regardless of sex. Among the Whites who were younger than 60 y, DSR was not related to FFM and FM (P = 0.73) but was affected by both age and sex (P < 0.001). Previous estimates of age-related decline in TEE may have overestimated TEE at age 90 y. Validation studies on older participants are required to confirm this finding.

Greater male variability in daily energy expenditure develops through puberty.

There is considerably greater variation in metabolic rates between men than between women, in terms of basal, activity and total (daily) energy expenditure (EE). One possible explanation is that EE is associated with male sexual characteristics (which are known to vary more than other traits) such as musculature and athletic capacity. Such traits might be predicted to be most prominent during periods of adolescence and young adulthood, when sexual behaviour develops and peaks. We tested this hypothesis on a large dataset by comparing the amount of male variation and female variation in total EE, activity EE and basal EE, at different life stages, along with several morphological traits: height, fat free mass and fat mass. Total EE, and to some degree also activity EE, exhibit considerable greater male variation (GMV) in young adults, and then a decreasing GMV in progressively older individuals. Arguably, basal EE, and also morphometrics, do not exhibit this pattern. These findings suggest that single male sexual characteristics may not exhibit peak GMV in young adulthood, however total and perhaps also activity EE, associated with many morphological and physiological traits combined, do exhibit GMV most prominently during the reproductive life stages.

Patterns of sedentary behavior and physical function in older adults.

BACKGROUND/AIMS: The purposes of this study were to examine the relationship between various objectively measured sedentary behavior (SB) variables and physical function in older adults, examine the measurement properties of an SB questionnaire, and describe the domains of SB in our sample. METHODS: Forty-four older adults (70 ± 8 years, 64 % female) had their SB measured via activPAL activity monitor and SB questionnaire for 1 week followed by performance-based tests of physical function. RESULTS: The pattern of SB was more important than total SB time. Where a gender by SB interaction was found, increasing time in SB and fewer breaks were associated with worse function in the males only. The SB questionnaire had acceptable test-retest reliability but poor validity compared to activPAL-measured SB. The majority of SB time was spent watching television, using the computer and reading. DISCUSSION/CONCLUSIONS: This study provides further evidence for the association between SB and physical function and describes where older adults are spending their sedentary time. This information can be used in the design of future intervention to reduce sedentary time and improve function in older adults.

Dose-response relationships between sedentary behaviour and the metabolic syndrome and its components.

AIMS/HYPOTHESIS: The aim of this study was to examine the relationship among sedentary behaviour (SB) and the metabolic syndrome and its components by age, moderate-to-vigorous physical activity (MVPA) and sex. METHODS: A cross-sectional analysis was performed on 2003-2006 National Health and Nutrition Examination Survey data from 5,076 adults aged ≥18 years (mean ± SD = 43.8 ± 19.5). SB was measured using ActiGraph accelerometers worn for 1 week and defined as <100 counts/min. Metabolic syndrome was defined using the Adult Treatment Panel III criteria. Natural cubic spline logistic regression models were used to estimate the odds of meeting criteria for the metabolic syndrome and its components by total daily SB time and breaks in SB. Statistical interactions between SB and age, sex and MVPA were explored. RESULTS: The prevalence of the metabolic syndrome was 19% and the average daily SB time was 8.1 ± 2.8 h, with 90 ± 25 breaks/day. The relationship between daily SB time and the metabolic syndrome was linear and characterised by an OR of 1.09 (95% CI 1.01, 1.18) for each hour of SB. Total SB was associated with the following components: high triacylglycerol, low HDL-cholesterol and high fasting glucose. All three associations were modified by MVPA level. No relationship between breaks in SB and the metabolic syndrome was found. CONCLUSIONS/INTERPRETATION: There appears to be no SB threshold at which the risk of the metabolic syndrome is elevated. Therefore, an effort should be made to maintain low levels of total time spent in SB and so lessen the risk of the metabolic syndrome.

Reliability and Validity of 2 Self-Report Measures to Assess Sedentary Behavior in Older Adults.

BACKGROUND: The purpose of this study was to examine the reliability and validity of 2 currently available physical activity surveys for assessing time spent in sedentary behavior (SB) in older adults. METHODS: Fifty-eight adults (≥65 years) completed the Yale Physical Activity Survey for Older Adults (YPAS) and Community Health Activities Model Program for Seniors (CHAMPS) before and after a 10-day period during which they wore an ActiGraph accelerometer (ACC). Intraclass correlation coefficients (ICC) examined test-retest reliability. Overall percent agreement and a kappa statistic examined YPAS validity. Lin's concordance correlation, Pearson correlation, and Bland-Altman analysis examined CHAMPS validity. RESULTS: Both surveys had moderate test-retest reliability (ICC: YPAS = 0.59 (P < .001), CHAMPS = 0.64 (P < .001)) and significantly underestimated SB time. Agreement between YPAS and ACC was low (κ = -0.0003); however, there was a linear increase (P < .01) in ACC-derived SB time across YPAS response categories. There was poor agreement between ACC-derived SB and CHAMPS (Lin's r = .005; 95% CI, -0.010 to 0.020), and no linear trend across CHAMPS quartiles (P = .53). CONCLUSIONS: Neither of the surveys should be used as the sole measure of SB in a study; though the YPAS has the ability to rank individuals, providing it with some merit for use in correlational SB research.

Smokers' physical activity and weight gain one year after a successful versus unsuccessful quit attempt.

OBJECTIVE: To examine whether smokers' physical activity is related to weight change following a quit attempt. METHOD: Data were analyzed for participants (n=683) of a randomized controlled trial comparing the efficacy of different smoking cessation pharmacotherapies (Wisconsin, 2005-2008). Activity (assessed via pedometry) and body weight were measured in the days surrounding the quit day and again one year later, at which time 7-day point-prevalence abstinence from smoking was assessed. We examined the effects of quitting, physical activity, and their interaction, on a one-year weight change with relevant covariate adjustment. RESULTS: Participants were predominantly female (57%), 46 ± 11 years of age (mean ± SD), and took 7544 ± 3606 steps/day at baseline. Of those who quit, 87% gained weight. A main effect was found for quitting (p<0.001), but not physical activity (p=0.06). When pattern of activity was examined across the 1-year study period, quitters who decreased their physical activity had significantly greater weight gain than quitters who increased their physical activity (p<0.01) or maintained a high level of activity (p=0.02). CONCLUSION: Physical activity is associated with an attenuation of the weight gain that often occurs after quitting smoking.

Greater physical activity is associated with better cognitive function in heart failure.

OBJECTIVE: Nearly 6 million Americans have heart failure (HF), up to 80% of which exhibit cognitive deficits on testing. Physical inactivity is common in HF, yet little is known about the possible contribution of physical inactivity to cognitive dysfunction in this population. METHOD: Older adults with HF (N = 93; Mage = 68.5 years, 33.7% women) completed neuropsychological testing, as well as cardiac and physical activity assessment as part of a larger protocol. HF severity was measured via impedance cardiography. Physical activity was assessed via an Actigraph accelerometer and operationalized using daily step count and time engaged in moderate-vigorous activity (minutes/day). RESULTS: Linear regression analyses controlling for sex, high blood pressure, diabetes, depressive symptomatology, and HF severity showed that greater physical activity (both step count and minutes spent in moderate-vigorous activity) was associated with better executive function/attention, processing speed, and scores on a screening measure of cognition. CONCLUSIONS: These findings indicate that physical activity is an independent predictor of cognitive function in persons with HF. Future work is needed to clarify the mechanisms by which physical activity benefits cognitive function in HF and determine whether interventions to promote physical activity can attenuate cognitive decline over time.

Reduced cognitive function predicts functional decline in patients with heart failure over 12 months.

BACKGROUND: Occurrences of impaired activities of daily living (ADL) are common in heart failure (HF) patients and contribute to the elevated mortality and hospitalization rates in this population. Cognitive impairment is also prevalent in HF, though its ability to predict functional decline over time is unknown. AIMS: This study examined the longitudinal pattern of activities of daily living (ADL) in HF persons and whether reduced baseline cognitive status predicts functional decline in this population. METHODS: Altogether 110 persons with HF completed the Lawton-Brody Instrumental Activities of Daily Living (IADL) scale and were administered the Modified Mini-Mental Status Examination (3MS) at baseline and a 12-month follow-up. Three composite scores were derived from the Lawton-Brody scale, including total, instrumental, and basic ADL. RESULTS: HF patients reported high rates of baseline impairments in instrumental ADL, including shopping, food preparation, housekeeping duties, laundry, among others. Repeated measures analyses showed significant declines in total and instrumental ADL from baseline to the 12-month follow-up in HF (p<0.05). Hierarchical regression analyses showed that poorer baseline performance on the 3MS predicted worse total ADL performance at 12-months (ß=0.15, p=0.049), including greater dependence in shopping, driving, feeding, and physical ambulation (p<0.05 for all). CONCLUSION: The current results show that HF patients report significant functional decline over a 12-month period and brief cognitive tests can identify those patients at highest risk for decline. If replicated, such findings encourage the use of cognitive screening measures to identify HF patients most likely to require assistance with ADL tasks.

Intensity of physical activity in the energy expenditure of older adults.

This study examined the intensity of activity contributing to physical activity energy expenditure in older adults. In 57 men and women aged ≥ 65, total energy expenditure (TEE) was measured using doubly labeled water and resting metabolic rate was measured using indirect calorimetry to calculate a physical activity index (PAI). Sedentary time and physical activity of light and moderate to vigorous (mod/vig) intensity was measured using an accelerometer. The subjects were 75 ± 7 yrs (mean ± SD) of age and 79% female. Subjects spent 66 ± 8, 25 ± 5, and 9 ± 4% of monitor wear time in sedentary, light, and mod/vig activity per day, respectively. In a mixture regression model, both light (ß = 29.6 [15.6-43.6, 95% CI]), p < .001) and mod/vig intensity activity (ß = 28.7 [7.4-50.0, 95% CI]), p = .01) were strongly associated with PAI, suggesting that both light and mod/vig intensity activities are major determinants of their physical activity energy expenditure.

Executive dysfunction is independently associated with reduced functional independence in heart failure.

AIMS AND OBJECTIVES: To examine the independent association between executive function with instrumental activities of daily living and health behaviours in older adults with heart failure. BACKGROUND: Executive function is an important contributor to functional independence as it consists of cognitive processes needed for decision-making, planning, organising and behavioural monitoring. Impairment in this domain is common in heart failure patients and associated with reduced performance of instrumental activities of daily living in many medical and neurological populations. However, the contribution of executive functions to functional independence and healthy lifestyle choices in heart failure patients has not been fully examined. DESIGN: Cross-sectional analyses. METHODS: One hundred and seventy-five heart failure patients completed a neuropsychological battery and echocardiogram. Participants also completed the Lawton-Brody Instrumental Activities of Daily Living Scale and reported current cigarette use. RESULTS: Hierarchical regressions revealed that reduced executive function was independently associated with worse instrumental activity of daily living performance with a specific association for decreased ability to manage medications. Partial correlations showed that executive dysfunction was associated with current cigarette use. CONCLUSIONS: Our findings suggest that executive dysfunction is associated with poorer functional independence and contributes to unhealthy behaviours in heart failure. Future studies should examine whether heart failure patients benefit from formal organisation schema (i.e. pill organisers) to maintain independence. RELEVANCE TO CLINICAL PRACTICE: Screening of executive function in heart failure patients may provide key insight into their ability to perform daily tasks, including the management of treatment recommendations.

Higher BMI is associated with reduced brain volume in heart failure.

BACKGROUND: Heart failure (HF) patients are at risk for structural brain changes due to cerebral hypoperfusion. Past work shows obesity is linked with reduced cerebral blood flow and associated with brain atrophy in healthy individuals, although its effects on the brain in HF are unclear. This study examined the association among body mass index (BMI), cerebral perfusion, and brain volume in HF patients. RESULTS: Eighty HF patients underwent transcranial Doppler sonography to quantify cerebral blood flow velocity of the middle cerebral artery (CBF-V of the MCA) and brain magnetic resonance imaging (MRI) to quantify total brain, total and subcortical gray matter, white matter volume, and white matter hyperintensities. Body mass index (BMI) operationalized weight status. Nearly 45% of HF patients exhibited a BMI consistent with obesity. Regression analyses adjusting for medical variables, demographic characteristics, and CBF-V of the MCA, showed increased BMI was associated with reduced white matter volume (p <.05). BMI also interacted with cerebral perfusion to impact total gray matter volume, but this pattern did not emerge for any other MRI indices (p < 0.05). CONCLUSIONS: Our findings suggest increased BMI negatively affects brain volume in HF, and higher BMI interacts with cerebral perfusion to impact gray matter volume. The mechanisms for these findings remain unclear and likely involve multiple physiological processes. Prospective studies are needed to elucidate the exact pattern and rates of brain changes in obese HF persons.

Lessons Learned from a Community Based Lifestyle Intervention for Youth at Risk for Type 2 Diabetes.

PURPOSE: This pilot study examined the feasibility and acceptability of a peer led diabetes prevention intervention for youth in an underserved community. METHODS: Children and adolescents randomized to the intervention group participated in a one year program which included peer support, physical activity, and family nutrition, and behavior modification sessions. Participants were asked about their satisfaction with the study and possible benefits, what they learned, and whether they would recommend participation to a friend. Youth randomized to the control group received monthly healthy lifestyle educational materials through the mail. RESULTS: Children and adolescents (n=67) with an average age of 12.5 years and BMI greater than or equal to 85 percentile for age and sex were enrolled in the study. The average monthly participation rate varied between 90 and 50 percent with a mean rate of 82 percent. Ninety four percent of parents reported being very satisfied with the program and all (100%) reported they would recommend the program to a friend. All the children and adolescents (100%) reported that they enjoyed working with the youth peer coaches and 94% felt their assigned coach was a good role model. The observed changes in BMI z-score trended towards improvement in the intervention group, but this study was underpowered to detect differences between groups. CONCLUSION: The peer led diabetes prevention program was feasible and acceptable and demonstrated potential for improving health behaviors.

Dietary habits moderate the association between heart failure and cognitive impairment.

Cognitive impairment is common in heart failure patients. Poor dietary habits are associated with reduced neurocognitive function in other medical populations, including diabetes and Alzheimer's disease. This study examined whether dietary habits help moderate the relationship between heart failure severity and cognitive function. A total of 152 persons with heart failure completed neuropsychological testing and a fitness assessment. Dietary habits were assessed using the Starting the Conversation-Diet questionnaire, a nutrition measure suggested for use in primary care settings. Moderation analyses showed that better dietary habits attenuated the adverse impact of heart failure severity on frontal functioning (b = 1.28, p < 0.05). Follow-up analyses revealed consumption of foods high in sodium was associated with reduced cognitive function (p < 0.05). This study suggests dietary habits can moderate the association between heart failure and performance on tests of attention and executive function. Longitudinal studies are needed to confirm and clarify the mechanisms for our findings.

Dose-response relationships between physical activity, social participation, and health-related quality of life in colorectal cancer survivors.

PURPOSE: The purpose of this study was to examine the relationships between physical activity (PA), social participation, and health-related quality of life (HQOL) in older, long-term colorectal cancer survivors. METHODS: Male and female colorectal cancer survivors (n = 1,768), aged ≥65 and ≥5 years post-diagnosis, completed surveys on their current PA, social participation, HQOL, health history, and relevant covariates. Analysis of covariance was used to evaluate the cross-sectional relationship between PA and social participation with the SF-36 subscales, as well as the physical component summary score (PCS) and mental health component summary score (MCS). RESULTS: The final analytic sample (n = 832) was 81.5 ± 5.8 years and 8.2 ± 1.7 years post-diagnosis (mean ± SD). Meeting the current recommendation of 150 min/week of PA was associated with higher PCS (p < 0.001) but not MCS (p = 0.30). Engaging in any social participation, vs. none, was associated with MCS (p = 0.003), but not PCS (p = 0.13). There was a dose-response relationship between moderate-vigorous-intensity PA and PCS (p trend<0.001). Light-intensity PA was not associated with either summary score after adjustment for moderate-vigorous PA (p > 0.05), but in survivors performing no higher-intensity PA, it was associated with both (p < 0.01, p = 0.02, respectively). Participants reporting greater amounts of both planned exercise and non-exercise PA had significantly higher PCS (p trend<0.01, p trend < 0.01, respectively). Individuals participating in greater weekly hours of social participation had higher PCS and MCS (p trend<0.05) than those participating in less. CONCLUSIONS: Among older, long-term colorectal cancer survivors, PA is related to their physical health, while social participation is predominantly related to their mental health. IMPLICATIONS FOR CANCER SURVIVORS: Older colorectal cancer survivors who participate socially and are engaged in PA, even non-exercise and light-intensity activities, have higher levels of physical and mental health.

Poorer physical fitness is associated with reduced structural brain integrity in heart failure.

OBJECTIVE: Physical fitness is an important correlate of structural and functional integrity of the brain in healthy adults. In heart failure (HF) patients, poor physical fitness may contribute to cognitive dysfunction and we examined the unique contribution of physical fitness to brain structural integrity among patients with HF. METHODS: Sixty-nine HF patients performed the Modified Mini Mental State examination (3MS) and underwent brain magnetic resonance imaging. All participants completed the 2-minute step test (2MST), a brief measure of physical fitness. We examined the associations between cognitive performance, physical fitness, and three indices of global brain integrity: total cortical gray matter volume, total white matter volume, and whole brain cortical thickness. RESULTS: Regression analyses adjusting for demographic characteristics, medical variables (e.g., left ventricular ejection fraction), and intracranial volume revealed reduced performance on the 2MST were associated with decreased gray matter volume and thinner cortex (p<.05). Follow up analyses showed that reduced gray matter volume and decreased cortical thickness were associated with poorer 3MS scores (p<.05). CONCLUSIONS: Poor physical fitness is common in HF and associated with reduced structural brain integrity. Prospective studies are needed to elucidate underlying mechanisms for the influence of physical fitness on brain health in HF.

Cerebral perfusion is associated with white matter hyperintensities in older adults with heart failure.

Cognitive impairment is common in heart failure (HF) and believed to be the result of cerebral hypoperfusion and subsequent brain changes including white matter hyperintensities (WMHs). The current study examined the association between cerebral blood flow and WMHs in patients with HF and the relationship between WMHs and cognitive impairment. Sixty-nine patients with HF completed the Mini-Mental State Examination (MMSE) and underwent echocardiography, transcranial Doppler sonography for cerebral blood flow velocity of the middle cerebral artery, and brain magnetic resonance imaging. Multivariable hierarchical regression analyses controlling for medical and demographic characteristics as well as intracranial volume showed reduced cerebral blood flow velocity of the middle cerebral artery was associated with greater WMHs (ß=-0.34, P=.02). Follow-up regression analyses adjusting for the same medical and demographic factors in addition to cerebral perfusion also revealed marginal significance between increased WMHs and poorer performance on the MMSE (ß=-0.26, P=.05). This study suggests that reduced cerebral perfusion is associated with greater WMHs in older adults with HF. These findings support the widely proposed mechanism of cognitive impairment in HF patients and prospective studies are needed to confirm these results.

Sedentary behavior, physical activity, and markers of health in older adults.

INTRODUCTION: The purpose of this study was to examine the association between sedentary behavior (SB), cardiometabolic risk factors, and self-reported physical function by level of moderate-vigorous physical activity (MVPA). METHODS: Cross-sectional analysis was completed on 1914 older adults age ≥ 65 yr from the 2003-2006 U.S. National Health and Nutrition Examination Survey. MVPA and SB were derived from ActiGraph accelerometers worn for 1 wk. MVPA was categorized as sufficient to meet the current U.S. guidelines (≥ 150 min · wk(-1)) or not; SB was split into quartiles. Various biomarkers were examined in laboratory analyses and physical exams, and the number of functional limitations was self-reported. Statistical interaction between SB and MVPA on the biomarker associations was the primary analysis, followed by an examination of their independent associations with relevant covariate adjustment. RESULTS: Average SB was 9.4 ± 2.3 h · d(-1) (mean ± SD), and approximately 35% were classified as sufficiently active. Overall, no significant meaningful statistical interactions were found between SB and MVPA for any of the outcomes; however, strong independent positive associations were found between SB and weight (P < 0.01), body mass index (P < 0.01), waist circumference (P < 0.01), C-reactive protein (P < 0.01), plasma glucose (P = 0.04), and number of functional limitations (P < 0.01) after adjustment for MVPA. Similarly, MVPA was negatively associated with weight (P = 0.01), body mass index (P < 0.01), waist circumference (P < 0.01), diastolic blood pressure (P = 0.04), C-reactive protein (P < 0.01), and number of functional limitations (P < 0.01) after adjustment for SB. CONCLUSIONS: The results suggest that sufficient MVPA did not ameliorate the negative associations between SB and cardiometabolic risk factors or functional limitations in the current sample and that there was independence on a multiplicative scale in their associations with the outcomes examined. Thus, older adults may benefit from the joint prescription to accumulate adequate MVPA and avoid prolonged sitting.

The adverse impact of type 2 diabetes on brain volume in heart failure.

OBJECTIVE: Heart failure (HF) is associated with structural brain abnormalities, including atrophy in multiple brain regions. Type 2 diabetes mellitus (T2DM) is a prevalent comorbid condition in HF and is associated with abnormalities on neuroimaging in other medical and elderly samples. The current study examined whether comorbid T2DM exacerbates brain atrophy in older adults with HF. METHODS: Seventy-five older adults with HF underwent an echocardiogram and completed a brief cognitive test battery. Participants then underwent brain magnetic resonance imaging (MRI) to quantify total brain volumes, cortical lobar volumes, and white matter hyperintensities (WMH). RESULTS: Approximately 30% of HF patients had a comorbid T2DM diagnosis. A series of multivariate analyses of covariance (MANCOVAs) adjusting for medical and demographic characteristics and intracranial volume showed that HF patients with T2DM had smaller total brain, gray matter, and subcortical gray matter volume than those without such history. No between-group differences emerged for WMH. Persons with T2DM also had smaller cortical lobar volumes, including in frontal, temporal, and parietal lobes. Follow-up analyses revealed that smaller total and cortical lobar brain volumes and WMH were associated with poorer performance on measures of global cognitive status, attention, executive functions, and memory. CONCLUSIONS: T2DM is associated with smaller total and cortical lobar brain volumes in patients with HF, and these structural brain indices were associated with cognitive test performance. Prospective studies that directly monitor glucose levels are needed to confirm our findings and clarify the mechanisms by which T2DM adversely impacts brain atrophy in this population.

Depressive symptomatology, exercise adherence, and fitness are associated with reduced cognitive performance in heart failure.

OBJECTIVE: Depression is common in heart failure (HF) and associated with reduced cognitive function. The current study used structrual equation modeling to examine whether depression adversely impacts cognitive function in HF through its adverse affects on exercise adherence and cardiovascular fitness. METHOD: 158 HF patients completed neuropsychological testing, physical fitness test, Beck depression inventory-II (BDI-II), and measures assessing exercise adherence and physical exertion. RESULTS: The model demonstrated excellent model fit and increased scores on the BDI-II negatively affected exercise adherence and cardiovascular fitness. There was a strong inverse association between cardiovascular fitness and cognitive function. Sobel test showed a significant indirect pathway between the BDI-II and cognitive function through cardiovascular fitness. DISCUSSION: This study suggests depression in HF may adversely impact cognitive function through reduced cardiovascular fitness. Prospective studies are needed to determine whether treatment of depression can lead to better lifestyle behaviors and ultimately improve neurocognitive outcomes in HF.

Obesity interacts with cerebral hypoperfusion to exacerbate cognitive impairment in older adults with heart failure.

BACKGROUND: Cerebral hypoperfusion accompanies heart failure (HF) and is associated with reduced cognitive performance. Obesity is prevalent in persons with HF and is also a likely contributor to cognitive function, as it has been independently linked to cognitive impairment in healthy individuals. The current study examined the association between obesity and cognitive performance among older adults with HF and whether obesity interacts with cerebral hypoperfusion to exacerbate cognitive impairment. METHODS: Patients with HF (n = 99, 67.46 ± 11.36 years of age) completed neuropsychological testing and impedance cardiography. Cerebral blood flow velocity (CBF-V) measured by transcranial Doppler sonography quantified cerebral perfusion and body mass index (BMI) operationalized obesity. RESULTS: A hierarchical regression analysis showed that lower CBF-V was associated with reduced performance on tests of attention/executive function and memory. Elevated BMI was independently associated with reduced attention/executive function and language test performance. Notably, a significant interaction between CBF-V and BMI indicated that a combination of hypoperfusion and high BMI has an especially adverse influence on attention/executive function in HF patients. CONCLUSIONS: The current findings suggest that cerebral hypoperfusion and obesity interact to impair cognitive performance in persons with HF. These results may have important clinical implications, as HF patients who are at high risk for cerebral hypoperfusion may benefit from weight reduction.