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.

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.

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.

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.

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.

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.

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 (β=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.

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.

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.

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.

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 (β=-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 (β=-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.

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.

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.

The independent association of hypertension with cognitive function among older adults with heart failure

OBJECTIVE

Hypertension is the most common comorbidity among heart failure (HF) patients and has been independently linked with cognitive impairment. Cognitive impairment is prevalent among HF patients, though the extent to which hypertension contributes to cognitive function in this population is unclear.

METHODS

116 HF patients (31.0% women, 67.68 ± 11.16 years) completed neuropsychological testing and impedance cardiography. History of physician diagnosed hypertension, along with other medical characteristics, was ascertained through a review of participants' medical charts.

RESULTS

69.8% of the HF patients had a diagnostic history of hypertension. After adjustment for demographic and medical characteristics (i.e., cardiac index, medication status, and resting blood pressure), hypertension was independently associated with attention/executive function/psychomotor speed (ΔF(1,103)=10.85, ΔR(2)=.07, p<.01) and motor functioning (ΔF(1,103)=4.46, ΔR(2)=.04, p<.05). HF patients with a diagnosed history of hypertension performed worse in these domains than those without such history.

CONCLUSION

The current findings indicate that diagnostic history of hypertension is an important contributor to cognitive impairment in HF. Hypertension frequently precedes HF and future studies should examine whether sustained hypertension compromises cerebral autoregulatory mechanisms to produce brain damage and exacerbate cognitive impairment in this population.

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.

Depression is associated with reduced physical activity in persons with heart failure

OBJECTIVE

Reduced physical activity is common in persons with heart failure (HF). However, studies of correlates and modifiers of physical activity in this population rarely employ objective measures. Motivational and mood related factors that may exacerbate inactivity in HF patients are also rarely investigated. In this study, we examined the relationship between physical activity as assessed by accelerometry, and depression in older adults with HF.

METHODS

At baseline, older adults with HF (N = 96; 69.81 ± 8.79) wore an accelerometer for seven days, and completed a brief fitness assessment, neuropsychological testing, and psychosocial measures including the Beck Depression Inventory-II (BDI-II). Medical and demographic history was obtained through record review and self-report.

RESULTS

Accelerometer measures showed that HF patients averaged 587 minutes of sedentary time and just 0.31 minutes of vigorous activity per day. Lower daily step count was associated with poorer quality of life and reduced cognitive function. A multiple linear regression adjusting for important demographic and medical variables found that greater number of depressive symptoms on the BDI-II independently predicted lower physical activity levels.

CONCLUSION

Consistent with past work, the current study found that low physical activity is common in older adults with HF. Depression is an independent predictor of physical activity in older adults with HF and reduced physical activity is associated with numerous adverse psychosocial outcomes. Future studies need to determine whether treatment of depression can boost physical activity and thus improve health outcomes in this population.

The additive effects of type-2 diabetes on cognitive function in older adults with heart failure

Background. Medical comorbidity has been theorized to contribute to cognitive impairment in heart failure (HF) patients. Specifically, type-2 diabetes mellitus (T2DM), a common coexisting condition among HF patients, may be an independent predictor of cognitive impairment. Nonetheless, the relationships between T2DM and other risk factors for cognitive impairment among persons with HF are unclear. Methods. Persons with HF (N = 169, 34.3% women, age 68.57 ± 10.28 years) completed neuropsychological testing within a framework of an ongoing study. History of T2DM, along with other medical characteristics, was ascertained through a review of participants' medical charts and self-report. Results. Many participants (34.9%) had a comorbid T2DM diagnosis. After adjustment for demographic and medical characteristics, HF patients with T2DM evidenced significantly greater impairments across multiple cognitive domains than HF patients without T2DM: λ = .92, F(5, 156) = 2.82, P = .018. Post hoc tests revealed significant associations between T2DM and attention (P = .003), executive function (P = .032), and motor functioning (P = .008). Conclusion. The findings suggest additive contributions of T2DM and HF to impairments in attention, executive function, and motor function. Future work is needed to elucidate the mechanisms by which T2DM exacerbates cognitive impairment in HF.

The 2-minute step test is independently associated with cognitive function in older adults with heart failure

BACKGROUND AND AIMS

Cognitive impairment is common in persons with heart failure (HF), and measures like the 6-minute walk test (6MWT) are known to correspond to level of impairment. The 2- minute step test (2MST) has been suggested as a more practical alternative to the 6MWT, though no study has examined whether it is associated with cognitive impairment in persons with HF. This study examined whether the 2MST is associated with cognitive function in older adults with HF.

METHODS

Older adults with HF (n=145; 68.97±9.31 yrs) completed the 2MST and a neuropsychological test battery that assessed function in multiple cognitive domains.

RESULTS

Consistent with past work, HF patients exhibited high rates of cognitive impairment. Hierarchical regression analyses adjusting for demographic and medical characteristics found that the 2MST accounted for unique variance in global cognitive function (ΔR²=0.09, p<0.001), executive function (ΔR²=0.03, p<0.05), and language (ΔR²=0.10, p<0.001). A trend emerged for attention (ΔR²=0.02, p=0.09). Follow-up tests indicated that better 2MST performance was significantly correlated with better global cognitive function, attention, executive, and language test performance.

CONCLUSION

The current results indicate that the 2MST is associated with cognitive function in older adults with HF. Further work is needed to clarify underlying mechanisms for this association and the value of implementing the 2MST during routine visits.

Cognitive reserve moderates the association between heart failure and cognitive impairment

BACKGROUND

Cognitive impairment in persons with heart failure is common. Theories of cognitive reserve suggest that premorbid factors, such as intellectual ability, may provide a buffer against cognitive impairment due to neuropathological insult. No study has examined the influence of cognitive reserve on cognitive functioning in older adults with heart failure.

AIM

This study examined whether cognitive reserve moderates the relationship between heart failure severity and cognitive function.

METHODS

A total of 157 persons with heart failure (69.26 ± 9.26 years; 39% female) completed neuropsychological testing and a brief fitness assessment. Cognitive reserve was operationalized using estimated premorbid intellect on the American National Adult Reading Test (AMNART).

RESULTS

A moderation analysis was performed using hierarchical regression models for each cognitive domain. An interaction term between the AMNART and 2-Minute Step Test was created and entered into the final block of the model, with demographic, psychosocial, and heart failure severity entered in the previous blocks. The interaction term was significant for attention, t(155) = -2.54, p = .012, executive function, t(155) = -3.30, p = .001, and language, t(155) = -2.83, p = .005, domains.

CONCLUSION

The current findings suggest that cognitive reserve moderates the association between heart failure severity and cognitive function in multiple cognitive domains. Further work is needed to clarify the mechanisms by which cognitive reserve attenuates cognitive impairment in this population.

Comparative validity of physical activity measures in older adults

PURPOSE

To compare the validity of various physical activity measures with doubly labeled water (DLW)-measured physical activity energy expenditure (PAEE) in free-living older adults.

METHODS

Fifty-six adults aged ≥65 yr wore three activity monitors (New Lifestyles pedometer, ActiGraph accelerometer, and a SenseWear (SW) armband) during a 10-d free-living period and completed three different surveys (Yale Physical Activity Survey (YPAS), Community Health Activities Model Program for Seniors (CHAMPS), and a modified Physical Activity Scale for the Elderly (modPASE)). Total energy expenditure was measured using DLW, resting metabolic rate was measured with indirect calorimetry, the thermic effect of food was estimated, and from these, estimates of PAEE were calculated. The degree of linear association between the various measures and PAEE was assessed, as were differences in group PAEE, when estimable by a given measure.

RESULTS

All three monitors were significantly correlated with PAEE (r=0.48-0.60, P<0.001). Of the questionnaires, only CHAMPS was significantly correlated with PAEE (r=0.28, P=0.04). Statistical comparison of the correlations suggested that the monitors were superior to YPAS and modPASE. Mean squared errors for all correlations were high, and the median PAEE from the different tools was significantly different from DLW for all but the YPAS and regression-estimated PAEE from the ActiGraph.

CONCLUSIONS

Objective devices more appropriately rank PAEE than self-reported instruments in older adults, but absolute estimates of PAEE are not accurate. Given the cost differential and ease of use, pedometers seem most useful in this population when ranking by physical activity level is adequate.

Are women with fibromyalgia less physically active than healthy women?

PURPOSE

The primary purpose was to quantify and compare physical activity in fibromyalgia (FM) patients to age-matched healthy controls using both objective and self-report measures. Secondary purposes were to compare self-reported and objective measurement of physical activity and to evaluate the relationship between physical activity and pain and mood.

METHOD

Patients with FM (n=39) and healthy controls (n=40) completed the International Physical Activity Questionnaire and wore an accelerometer at the hip for 7 d. Pain and mood were measured using the McGill Pain Questionnaire, Pain Catastrophizing Scale, Beck Depression Inventory, State-Trait Anxiety Inventory, Profile of Mood States, and Fibromyalgia Impact Questionnaire.

RESULTS

FM patients had significantly lower physical activity than controls measured by both the International Physical Activity Questionnaire and accelerometer (P<0.05). Both groups self-reported significantly greater moderate and vigorous physical activities than were measured by the accelerometer (P < 0.05). Self-reported and objective measures of time spent in different intensities of activity showed significant correlations in healthy controls (r=0.41-0.51, ρ=0.41, P<0.05). No significant correlations between measures were found in FM patients (P>0.05). Finally, physical activity levels were negatively related (r=-0.37, P<0.05) to depressed mood for FM patients and positively related (r=-0.41, P<0.05) to self-reported vigor for healthy controls.

CONCLUSIONS

This controlled study objectively demonstrates that FM patients are less physically active than healthy controls, thus extending on two earlier investigations that did not show differences in total physical activity levels using wrist-mounted actigraphy methods. Physical activity levels were not predictive of pain in FM but were significantly related to depressed mood. FM patients may also have a greater variability in their manner of self-report than healthy controls. Therefore, physical activity measurement in FM patients should not be limited solely to self-report measures.

Physical performance and subsequent disability and survival in older adults with malignancy: results from the health, aging and body composition study

OBJECTIVES

To evaluate objective physical performance measures as predictors of survival and subsequent disability in older patients with cancer.

DESIGN

Longitudinal cohort study.

SETTING

Health, Aging and Body Composition (Health ABC) Study.

PARTICIPANTS

Four hundred twenty-nine individuals diagnosed with cancer during the first 6 years of follow-up of the Health ABC Study.

MEASUREMENTS

The associations between precancer measures of physical performance (20-m usual gait speed, 400-m long-distance corridor walk (LDCW), and grip strength) and overall survival and a short-term outcome of 2-year progression to disability or death were evaluated. Cox proportional hazards and logistic regression models, stratified for metastatic disease, respectively, were used for outcomes.

RESULTS

Mean age was 77.2, 36.1% were women, and 45.7% were black. Faster 20-m usual walking speed was associated with a lower risk of death in the metastatic group (hazard ratio=0.89, 95% confidence interval (CI)=0.79-0.99) and lower 2-year progression to disability or death in the nonmetastatic group (odds ratio (OR)=0.77, 95% CI=0.64-0.94). Ability to complete the 400-m LDCW was associated with lower 2-year progression to disability or death in the nonmetastatic group (OR=0.24, 95% CI=0.10-0.62). There were no associations between grip strength and disability or death.

CONCLUSION

Lower extremity physical performance tests (usual gait speed and 400-m LDCW) were associated with survival and 2-year progression to disability or death. Objective physical performance measures may help inform pretreatment evaluations in older adults with cancer.

Exercise effects on tumorigenesis in a p53-deficient mouse model of breast cancer

PURPOSE

Physically active women have a reduced risk of breast cancer, but the dose of activity necessary and the role of energy balance and other potential mechanisms have not been fully explored in animal models. We examined treadmill and wheel running effects on mammary tumorigenesis and biomarkers in p53-deficient (p53(+/-)):MMTV-Wnt-1 transgenic mice.

METHODS

Female mice (9 wk old) were randomly assigned to the following groups in experiment 1: treadmill exercise 5 d x wk(-1), 45 min x d(-1), 5% grade at 20 m x min(-1), approximately 0.90 km x d(-1) (TREX1, n = 20) or at 24 m x min(-1), approximately 1.08 km x d(-1) (TREX2, n = 21); or a nonexercise control (CON-TREX, n = 22). In experiment 2, mice were randomly assigned to voluntary wheel running (WHL, n = 21, 2.46 +/- 1.11 km x d(-1) (mean +/- SD)) or to a nonexercise control (CON-WHL, n = 22). Body composition was measured at approximately 9 wk and serum insulin-like growth factor 1 (IGF-1) at two to three monthly time points beginning at approximately 9 wk on study. Mice were sacrificed when tumors reached 1.5 cm, mice became moribund, or there was only one mouse per treatment group remaining.

RESULTS

TREX1 (24 wk) and TREX2 (21 wk) had shorter median survival times than CON-TREX (34 wk; P < 0.01), whereas those of WHL and CON-WHL were similar (23 vs 24 wk; P = 0.32). TREX2 had increased multiplicity of mammary gland carcinomas compared with CON-TREX; WHL had a higher tumor incidence than CON-WHL. All exercising animals were lighter than their respective controls, and WHL had lower body fat than CON-WHL (P < 0.01). There was no difference in IGF-1 between groups (P > 0.05).

CONCLUSIONS

Despite beneficial or no effects on body weight, body fat, or IGF-1, exercise had detrimental effects on tumorigenesis in this p53-deficient mouse model of spontaneous mammary cancer.

Activity energy expenditure and change in body composition in late life

BACKGROUND

Change in body composition, specifically loss of fat-free mass and gain in fat mass, in older adults is a major pathway leading to the onset of functional decline and physical disability.

OBJECTIVE

The objective was to determine the association of activity-related energy expenditure with change in body mass and composition among older men and women.

DESIGN

Total energy expenditure (TEE) was assessed over 2 wk by using the doubly labeled water method in 302 community-dwelling older adults aged 70-82 y. Resting metabolic rate (RMR) was measured by using indirect calorimetry, and the thermic effect of meals was estimated at 10% of TEE. Activity energy expenditure (AEE) was calculated as [TEE(0.9) - RMR]. Total body mass, fat-free mass (FFM), and fat mass (FM) were assessed by dual-energy X-ray absorptiometry annually over a mean (+/-SD) of 4.9 +/- 1.3 y.

RESULTS

In multivariate models adjusted for baseline age, smoking status, and race, men and women had a decline (in kg/y) in body mass (men: -0.34, 95% CI: -0.71, 0.02; women: -0.45, 95% CI: -0.71, -0.19) and FFM (men: -0.48, 95% CI: -0.67, -0.29; women: -0.14, 95% CI: -0.026, -0.03). No changes (in kg/y) were observed in FM (men: 0.14, 95% CI: -0.10, 0.38; women: -0.28, 95% CI: -0.49, -0.07). In men and women, higher AEE at baseline was associated with greater FFM. The average change in these outcomes (ie, slope), however, was similar across tertiles of AEE.

CONCLUSIONS

These data suggest that accumulated energy expenditure from all physical activities is associated with greater FFM, but the effect does not alter the trajectory of FFM change in late life.

Higher inflammatory marker levels in older persons: associations with 5-year change in muscle mass and muscle strength

BACKGROUND

There is growing evidence that higher levels of inflammatory markers are associated with physical decline in older persons, possibly through the catabolic effects of inflammatory markers on muscle. The aim of this study was to investigate the association between serum levels of inflammatory markers and loss of muscle mass and strength in older persons.

METHODS

Using data on 2,177 men and women in the Health, Aging, and Body Composition Study, we examined 5-year change in thigh muscle area estimated by computed tomography and grip and knee extensor strength in relation to serum levels of interleukin-6 (IL-6), C-reactive protein, tumor necrosis factor-alpha (TNF-alpha), and soluble receptors (measured in a subsample) at baseline.

RESULTS

Higher levels of inflammatory markers were generally associated with greater 5-year decline in thigh muscle area. Most associations, with the exception of soluble receptors, were attenuated by adjustment for 5-year change in weight. Higher TNF-alpha and interleukin-6 soluble receptor levels remained associated with greater decline in grip strength in men. Analyses in a subgroup of weight-stable persons showed that higher levels of TNF-alpha and its soluble receptors were associated with 5-year decline in thigh muscle area and that higher levels of TNF-alpha were associated with decline in grip strength.

CONCLUSIONS

TNF-alpha and its soluble receptors showed the most consistent associations with decline in muscle mass and strength. The results suggest a weight-associated pathway for inflammation in sarcopenia.

Activity energy expenditure and mobility limitation in older adults: differential associations by sex

In this study, the authors aimed to determine whether higher activity energy expenditure, assessed by using doubly labeled water, was associated with a reduced decline in mobility limitation among 248 older community-dwelling US adults aged 70-82 years enrolled in 1998-1999. Activity energy expenditure was calculated as total energy expenditure (assessed over 2 weeks by using doubly labeled water) minus resting metabolic rate (measured with indirect calorimetry), with adjustment for the thermic effect of food. Across sex-specific tertiles of activity energy expenditure, men in the lowest activity group experienced twice the rate of mobility limitation as men in the highest activity group (41% (n = 18) vs. 18% (n = 8)). Conversely, women in the lowest and highest activity groups exhibited similarly high rates of mobility limitation (40% (n = 16) vs. 38% (n = 15)). After adjustment for potential confounders, men with higher activity energy expenditure levels continued to show reduced risk of mobility limitation (per standard deviation (284 kcal/day): hazard ratio = 0.61, 95% confidence interval: 0.41, 0.92). Women showed no association (per standard deviation (226 kcal/day): hazard ratio = 1.34, 95% confidence interval: 0.98, 1.85). Greater energy expenditure from any and all physical activity was significantly associated with reduced risk of developing mobility limitation among men, but not among women.

Physical activity and function in older, long-term colorectal cancer survivors

OBJECTIVE

Increasing age and cancer history are related to impaired physical function. Since physical activity has been shown to ameliorate age-related functional declines, we evaluated the association between physical activity and function in older, long-term colorectal cancer survivors.

METHODS

In 2006-2007, mailed surveys were sent to colorectal cancer survivors, aged > or = 65 years when diagnosed during 1995-2000, and identified through a state cancer registry. Information on physical activity, physical function, and relevant covariates was obtained and matched to registry data. Analysis of covariance and linear regression were used to compare means and trends in physical function across levels of activity in the final analytic sample of 843 cases.

RESULTS

A direct, dose-dependent association between physical activity and function was observed (p(trend) < .001), with higher SF-36 physical function subscores in those reporting high versus low activity levels (65.0 +/- 1.7 vs. 42.7 +/- 1.7 (mean +/- standard error)). Walking, gardening, housework, and exercise activities were all independently related to better physical function. Moderate-vigorous intensity activity (p(trend) < .001) was associated with function, but light activity (p(trend) = 0.39) was not.

CONCLUSION

Results from this cross-sectional study indicate significant associations between physical activity and physical function in older, long-term colorectal cancer survivors.

Physical activity during pregnancy and age at menarche of the daughter

In utero exposures have been proposed as possible determinants of later disease risk. Given that a later age at menarche is a breast cancer risk factor, and that higher childhood physical activity has been associated with a later menarcheal age, it is possible that a pregnant mother's activity may also influence this outcome. The purpose of this study was to determine if a mother's physical activity during pregnancy is related to their daughter's menarcheal age. Participants of the Nurses' Health Study II reported their age at menarche to the nearest year, whereas their mothers (n=33,016) completed surveys regarding their health and lifestyle habits during their pregnancy with their daughters. Mothers reported their home, occupational, and leisure-time physical activities, as well as the activity of their daughters at ages 5 to 10 years. Using multiple linear regression analysis with adjustment for specific covariates including daughter's childhood body size, neither home nor occupational activity alone were associated with age at menarche of the daughter, but there was a direct association with leisure-time physical activity (P(trend)<0.001). Compared with women inactive in their leisure-time, women who were highly active had daughters with menarche 1.1 (95% confidence interval, 0.3-1.9) months later. Using a composite variable of both home and leisure-time activity, daughters of women who were highly active at home and in their leisure-time had daughters with menarche 3.1 (95% confidence interval, 0.4-5.9) months later than those who were highly inactive in both. Physical activity during pregnancy may be associated with a modest delay in menarcheal age in offspring.

Reducing the weight of cancer: mechanistic targets for breaking the obesity-carcinogenesis link

The prevalence of obesity, an established epidemiologic risk factor for many cancers, has risen steadily for the past several decades in the US. The increasing rates of obesity among children are especially alarming and suggest continuing increases in the rates of obesity-related cancers for many years to come. Unfortunately, the mechanisms underlying the association between obesity and cancer are not well understood. In particular, the effects on the carcinogenesis process and mechanistic targets of interventions that modulate energy balance, such as reduced-calorie diets and physical activity, have not been well characterized. The purpose of this review is to provide a strong foundation for the translation of mechanism-based research in this area by describing key animal and human studies of energy balance modulations involving diet or physical activity and by focusing on the interrelated pathways affected by alterations in energy balance. Particular attention is placed on signaling through the insulin and insulin-like growth factor-1 receptors, including components of the Akt and mammalian target of rapamycin (mTOR) signaling pathways downstream of these growth factor receptors. These pathways have emerged as potential targets for disrupting the obesity-cancer link. The ultimate goal of this work is to provide the missing mechanistic information necessary to identify targets for the prevention and control of cancers related to or caused by excess body weight.

Physical activity and cancer prevention : pathways and targets for intervention

The prevalence of obesity, an established epidemiological risk factor for many cancers, has risen steadily for the past several decades in the US and many other countries. Particularly alarming are the increasing rates of obesity among children, portending continuing increases in the rates of obesity and obesity-related cancers for many years to come. Modulation of energy balance, via increased physical activity, has been shown in numerous comprehensive epidemiological reviews to reduce cancer risk. Unfortunately, the effects and mechanistic targets of physical activity interventions on the carcinogenesis process have not been thoroughly characterized. Studies to date suggest that exercise can exert its cancer-preventive effects at many stages during the process of carcinogenesis, including both tumour initiation and progression. As discussed in this review, exercise may be altering tumour initiation events by modifying carcinogen activation, specifically by enhancing the cytochrome P450 system and by enhancing selective enzymes in the carcinogen detoxification pathway, including, but not limited to, glutathione-S-transferases. Furthermore, exercise may reduce oxidative damage by increasing a variety of anti-oxidant enzymes, enhancing DNA repair systems and improving intracellular protein repair systems. In addition to altering processes related to tumour initiation, exercise may also exert a cancer-preventive effect by dampening the processes involved in the promotion and progression stages of carcinogenesis, including scavenging reactive oxygen species (ROS); altering cell proliferation, apoptosis and differentiation; decreasing inflammation; enhancing immune function; and suppressing angiogenesis. A paucity of data exists as to whether exercise may be working as an anti-promotion strategy via altering ROS in initiated or preneoplastic models; therefore, no conclusions can be made about this possible mechanism. The studies directly examining cell proliferation and apoptosis have shown that exercise can enhance both processes, which is difficult to interpret in the context of carcinogenesis. Studies examining the relationship between exercise and chronic inflammation suggest that exercise may reduce pro-inflammatory mediators and reduce the state of low-grade, chronic inflammation. Additionally, exercise has been shown to enhance components of the innate immune response (i.e. macrophage and natural killer cell function). Finally, only a limited number of studies have explored the relationship between exercise and angiogenesis; therefore, no conclusions can be made currently about the role of exercise in the angiogenesis process as it relates to tumour progression. In summary, exercise can alter biological processes that contribute to both anti-initiation and anti-progression events in the carcinogenesis process. However, more sophisticated, detailed studies are needed to examine each of the potential mechanisms contributing to an exercise-induced decrease in carcinogenesis in order to determine the minimum dose, duration and frequency of exercise needed to yield significant cancer-preventive effects, and whether exercise can be used prescriptively to reverse the obesity-induced physiological changes that increase cancer risk.

Energy balance and carcinogenesis: underlying pathways and targets for intervention

The prevalence of obesity, an established epidemiologic risk factor for many cancers, has risen steadily for the past several decades in the U.S. Particularly alarming are the increasing rates of obesity among children, portending continuing increases in the rates of obesity and obesity-related cancers for many years to come. Unfortunately, the mechanisms underlying the association between obesity and cancer are not well understood. In particular, the effects and mechanistic targets of interventions that modulate energy balance, such as reduced calorie diets and physical activity, on the carcinogenesis process have not been well characterized. The purpose of this review is to provide a strong foundation for future mechanistic-based research in this area by describing key animal and human studies of energy balance modulations involving diet, exercise, or pharmaceutical agents and by focusing on the interrelated pathways affected by alterations in energy balance. Particular attention in this review is placed on the components of the insulin/IGF-1/Akt pathway, which has emerged as a predominant target for disrupting the obesity-cancer link. Also discussed is the promise of global approaches, including genomics, proteomics, and metabolomics, for the elucidation of energy balance-responsive pathways. The ultimate goal of this work is to provide the missing mechanistic information necessary to identify targets for the prevention and control of cancers related to or caused by excess body weight.

Intestinal microbiota: a potential diet-responsive prevention target in ApcMin mice

We previously reported that two dietary regimens, calorie restriction (CR) and a high olive oil-containing diet supplemented with a freeze-dried fruit and vegetable extract (OFV), reduced the development of intestinal adenomas in Apc(Min) mice by 57% and 33%, respectively, compared to control mice fed a defined diet ad libitum. The OFV diet was designed to have a strong effect on the composition of the intestinal microbiota through its high content of fiber, which represents a major source of fermentable substrate for the gut bacteria. We hypothesized that some of the observed effects of diet on intestinal carcinogenesis might be mediated by diet-related changes in the bacterial species that thrive in the gut. Therefore, we determined by fluorescent in situ hybridization (FISH) and denaturing gradient gel electrophoresis (DGGE) how the dietary interventions affected the composition of the intestinal microbiota, and we characterized specific microbiota changes that were associated with diet and reduced intestinal carcinogenesis. The OFV diet changed the overall composition of the intestinal microbiota, smaller changes were observed for the CR diet. Furthermore, we detected a 16S rDNA fragment associated with mice that did not develop polyps. Sequence analysis suggested that hitherto unidentified bacteria belonging to the family Lachnospiraceae (order Clostridiales) were its source. Thus, these bacteria may be an indicator of intestinal conditions associated with reduced intestinal carcinogenesis in Apc(Min) mice.

Association Between Infant Birth Weight and Maternal Cardiovascular Risk Factors in the Health, Aging, and Body Composition Study

PURPOSE

Mothers who deliver a low-birth-weight (LBW) infant may themselves be at excess risk for cardiovascular disease. We investigated whether older women who bore LBW infants had higher blood pressure, lipid, glucose, insulin, interleukin 6 (IL-6), and C-reactive protein concentrations, and pulse wave velocity compared to women with normal-weight births.

METHODS

Participants were 446 women with a mean age of 80 years and 47% black. Women reported birth weight and complications for each pregnancy. Analysis was limited to first births not complicated by hypertension or preeclampsia.

RESULTS

Women who had delivered a first-birth infant weighing less than 2500 g had a lower body mass index (BMI) compared with women with a normal-weight (>or=2500 g) infant (26.7 versus 28.4 kg/m2; p=0.02), but they had a larger abdominal circumference for BMI (97.9 versus 95.5 cm; p=0.05). They also were marginally more likely to be administered antihypertensive medication (p=0.06). After adjustment for BMI, race, and age, women with a history of a small infant had elevations in systolic blood pressure (p=0.05) and greater IL-6 levels (p=0.02) and were more insulin resistant (p=0.05) compared with women with a normal-weight infant.

CONCLUSIONS

These findings suggest that a history of LBW delivery identifies women with elevated cardiovascular risk factors.

Diabetes, hyperglycemia, and inflammation in older individuals: the health, aging and body composition study

OBJECTIVE

The objective of this study was to assess the association of inflammation with hyperglycemia (impaired fasting glucose [IFG]/impaired glucose tolerance [IGT]) and diabetes in older individuals.

RESEARCH DESIGN AND METHODS

Baseline data from the Health, Aging and Body Composition study included 3,075 well-functioning black and white participants, aged 70-79 years.

RESULTS

Of the participants, 24% had diabetes and 29% had IFG/IGT at baseline. C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-alpha) levels (P < 0.001) were significantly higher among diabetic participants and those with IFG/IGT. Odds of elevated IL-6 and TNF-alpha (>75th percentile) were, respectively, 1.95 (95% CI 1.56-2.44) and 1.88 (1.51-2.35) for diabetic participants and 1.51 (1.21-1.87) and 1.14 (0.92-1.42) for those with IFG/IGT after adjustment for age, sex, race, smoking, alcohol intake, education, and study site. Odds ratios for elevated CRP were 2.90 (2.13-3.95) and 1.45 (1.03-2.04) for diabetic women and men and 1.33 (1.07-1.69) for those with IFG/IGT regardless of sex. After adjustment for obesity, fat distribution, and inflammation-related conditions, IL-6 remained significantly related to both diabetes and IFG/IGT. CRP in women and TNF-alpha in both sexes were significantly related to diabetes, respectively, whereas risk estimates for IFG/IGT were decreased by adjustment for adiposity. Among diabetic participants, higher levels of HbA(1c) were associated with higher levels of all three markers of inflammation, but only CRP remained significant after full adjustment.

CONCLUSIONS

Our findings show that dysglycemia is associated with inflammation, and this relationship, although consistent in diabetic individuals, also extends to those with IFG/IGT.

Physical activity and the risk of colon cancer among women: a prospective cohort study (United States)

Physical activity has frequently been reported to decrease the risk of colon cancer in men, but data on the relation of physical activity to colon cancer risk in women have generally been less consistent. To further investigate the relationship of physical activity with colon cancer risk in women, we studied a cohort of 31,783 US women participating in the Breast Cancer Detection Demonstration Project Follow-up Study. Information on daily physical activity over the past year was ascertained using a self-administered questionnaire at study baseline. The Cox proportional hazards model was used to estimate relative risks (RRs) relating physical activity to the risk of incident colon cancer. During 270,325 person-years of follow-up, 243 colon cancer cases were identified. No association was observed between physical activity and the subsequent risk of colon cancer. The multivariable RRs of colon cancer across increasing quintiles of total physical activity were 1.0, 1.45, 1.16, 1.27 and 1.15 (95% CI: 0.76, 1.75; p(trend) = 0.77). The multivariable RRs comparing women at the extremes of moderate and vigorous physical activity, respectively, were 1.07 (95% CI: 0.70, 1.62) and 1.10 (95% CI: 0.78, 1.55). The relationship between physical activity and colon cancer risk did not vary by anatomic subsite or across subgroups defined by age, body mass, dietary fiber intake, menopausal status, menopausal hormone use or aspirin use. The results of this large prospective cohort study among women do not support the hypothesis that physical activity is related to a lower incidence of colon cancer.

Influence of marital status on physical activity levels among older adults

PURPOSE

The purpose of these analyses was to describe the levels and types of activity in relationship to current marital status among older adults and determine if the physical activity level of the husband was related to the physical activity level of his wife.

METHODS

Participants included 3075 well-functioning white and black men and women aged 70-79 yr with further examination of 345 spousal pairs. Marital status was self-reported and participants were grouped as married versus not married. Based on responses to a leisure-time questionnaire, total physical activity was calculated and participants were classified as low or high active. Descriptive statistics were used to describe level and proportions of type of activity by marital status. Logistic regression was used to determine if marital status was an important determinant of physical activity participation. Regression models were adjusted for demographics, body mass index (BMI), and chronic disease conditions.

RESULTS

When compared with their single counterparts, married men reported higher median levels of exercise participation (P = 0.008) and married women reported higher levels of total (P < 0.0001) and nonexercise activity (P < 0.0001) with a trend toward higher exercise participation (P = 0.05). In spousal pairs, compared with men in the low active group, highly active men were almost three times as likely (OR = 2.97; 95% CI = 1.73, 5.10) to have a similarly active spouse. The model only modestly attenuated when adjusted for age, BMI, and health status of the husband [OR = 2.49 (1.41, 4.42)].

CONCLUSIONS

Marital status and spousal physical activity (PA) levels are important determinants for PA participation among older adults.

Daily activity energy expenditure and mortality among older adults

CONTEXT

Exercise is associated with mortality benefits but simply expending energy through any activity in an individual's free-living environment may confer survival advantages.

OBJECTIVE

To determine whether free-living activity energy expenditure is associated with all-cause mortality among older adults.

DESIGN, SETTING, AND PARTICIPANTS

Free-living activity energy expenditure was assessed in 302 high-functioning, community-dwelling older adults (aged 70-82 years). Total energy expenditure was assessed over 2 weeks using doubly labeled water. Resting metabolic rate was measured using indirect calorimetry and the thermic effect of meals was estimated at 10% of total energy expenditure. Free-living activity energy expenditure was calculated as: (total energy expenditure x 0.90) - resting metabolic rate. Participants were followed up over a mean of 6.15 years (1998-2006).

MAIN OUTCOME MEASURES

Free-living activity energy expenditure (3 tertiles: low, <521 kcal/d; middle, 521-770 kcal/d; high, >770 kcal/d) and all-cause mortality.

RESULTS

Fifty-five participants (18.2%) died during follow-up. As a continuous risk factor, an SD increase in free-living activity energy expenditure (287 kcal/d) was associated with a 32% lower risk of mortality after adjusting for age, sex, race, study site, weight, height, percentage of body fat, and sleep duration (hazard ratio, 0.68; 95% confidence interval, 0.48-0.96). Using the same adjustments, individuals in the highest tertile of free-living activity energy expenditure were at a significantly lower mortality risk compared with the lowest tertile (hazard ratio, 0.31; 95% confidence interval, 0.14-0.69). Absolute risk of death was 12.1% in the highest tertile of activity energy expenditure vs 24.7% in the lowest tertile; absolute risks were similar to these for tertiles of physical activity level. The effect of free-living activity energy expenditure changed little after further adjustment for self-rated health, education, prevalent health conditions, and smoking behavior. According to self-reports, individuals expending higher levels of free-living activity energy were more likely to work for pay (P = .004) and climb stairs (P = .01) but self-reported high-intensity exercise, walking for exercise, walking other than for exercise, volunteering, and caregiving did not differ significantly across the activity energy expenditure tertiles.

CONCLUSIONS

Objectively measured free-living activity energy expenditure was strongly associated with lower risk of mortality in healthy older adults. Simply expending energy through any activity may influence survival in older adults.

Negative energy balance induced by voluntary wheel running inhibits polyp development in APCMin mice

Treadmill running of approximately 0.9 km/day has had inconsistent effects on spontaneous intestinal polyp development in C57BL/6J-Apc(Min)/J (Min) mice; the amount of energy expenditure and/or a lack of hormonal changes could account for this variability. The purpose of this study was to examine the effects of a negative energy balance induced by voluntary wheel running on polyps, insulin-like growth factor-1 (IGF-1) and corticosterone in Min mice. Seven-week-old male Min mice were randomly assigned to control (CON, n = 23) or wheel running (EX, n = 24) conditions for a 10-week study period. All mice had water and AIN-76A diet ad libitum for the first approximately 3 weeks on study, after which the EX group was pair-fed to the CON group to maintain a negative energy balance due to the exercise. EX mice voluntarily ran 3.8 km/day (2.7-6.0 km/day) (median, interquartile range) and weighed less than CON mice throughout the study. More CON mice died before the end of the study versus EX mice (26 versus 0%, P < 0.01). CON mice had significantly more polyps versus EX mice (21.6 +/- 1.5 versus 16.9 +/- 2.0, P < 0.01; mean +/- SE), and daily running distance in EX was inversely correlated with total polyp number (r = -0.70, P < 0.01). Urinary corticosterone output (P < 0.01) and serum IGF-1 were significantly higher in EX than CON (P < 0.001); however, total polyp number was unrelated to corticosterone (r = 0.05, P = 0.84) and IGF-1 (r = -0.01, P = 0.93). In this study, a negative energy balance produced by wheel running exercise and restricted feeding decreased polyp burden in male Min mice and appeared to have a dose-response effect on polyp number. Although EX affected IGF-1 and corticosterone, neither marker was related to total polyp number.

Estrogen replacement, muscle composition, and physical function: The Health ABC Study

PURPOSE

Although the beneficial effects of estrogen use on cardiovascular and cognitive function in postmenopausal women have been recently discredited, controversy remains regarding its usefulness for maintaining skeletal muscle mass or strength. Therefore, the purpose of this study was to determine whether estrogen use is associated with enhanced muscle composition and, if so, whether this translates into improved strength and physical function.

METHODS

Cross-sectional analysis of 840 well-functioning community-dwelling white women (current estrogen replacement therapy (ERT) users = 259, nonusers = 581) aged 70-79 yr participating in the Health, Aging and Body Composition Study. Muscle composition of the midthigh by computed tomography included cross-sectional area (CSA) of the quadriceps, hamstrings, intermuscular fat and subcutaneous fat, and muscle attenuation in Hounsfield units (HU) as a measure of muscle density. Isometric hand grip and isokinetic knee extensor strength were assessed by dynamometry. Physical function was assessed using a summary scale that included usual 6-m walk and narrow walk speed, repeated chair stands, and standing balance.

RESULTS

In analyses of covariance adjusted for relevant confounders, quadriceps muscle CSA and HU were greater in current ERT than non-ERT women (P < 0.05). Grip strength was also greater (P < 0.05) in women taking ERT while knee extensor strength approached significance (P < 0.10). However, differences in muscle composition and strength were modest at < or =3.3%. There was no difference by ERT status for the hamstring muscles, fat CSA, or for physical function.

CONCLUSION

The associations between ERT and muscle composition and strength were minor and did not translate into improved physical function. Initiation of ERT for preservation of muscle composition and function may not be indicated.