Cardiopulmonary Fitness Is Associated with Cognitive Performance in Patients with Coronary Artery Disease

Cytochrome P450-soluble epoxide hydrolase oxylipins, depression and cognition in type 2 diabetes

AIMS

This study examined serum cytochrome P450-soluble epoxide hydrolase (CYP450-sEH) oxylipins and depressive symptoms together in relation to cognitive performance in individuals with type 2 diabetes mellitus (T2DM).

METHODS

Clinically cognitively normal T2DM individuals were recruited (NCT04455867). Depressive symptom severity was assessed using the Beck Depression Inventory-II (BDI-II; total scores ≤13 indicated minimal depressive symptoms and ≥ 14 indicated significant depressive symptoms). Executive function and verbal memory were assessed. Fasting serum oxylipins were quantified by ultra-high-performance liquid chromatography tandem mass-spectrometry.

RESULTS

The study included 85 participants with minimal depressive symptoms and 27 with significant symptoms (mean age: 63.3 ± 9.8 years, 49 % women). In all participants, higher concentrations of linoleic acid derived sEH (12,13-dihydroxyoctadecamonoenoic acid; DiHOME) and CYP450 (12(13)-epoxyoctadecamonoenoic acid; EpOME) metabolites were associated with poorer executive function (F1,101 = 6.094, p = 0.015 and F1,101 = 5.598, p = 0.020, respectively). Concentrations of multiple sEH substrates interacted with depressive symptoms to predict 1) poorer executive function, including 9(10)-EpOME (F1,100 = 12.137, p < 0.001), 5(6)-epoxyeicosatrienoic acid (5(6)-EpETrE; F1,100 = 6.481, p = 0.012) and 11(12)-EpETrE (F1,100 = 4.409, p = 0.038), and 2) verbal memory, including 9(10)-EpOME (F1,100 = 4.286, p = 0.041), 5(6)-EpETrE (F1,100 = 6.845, p = 0.010), 11(12)-EpETrE (F1,100 = 3.981, p = 0.049) and 14(15)-EpETrE (F1,100 = 5.019, p = 0.027).

CONCLUSIONS

Associations of CYP450-sEH metabolites and depressive symptoms with cognition highlight the biomarker and therapeutic potential of the CYP450-sEH pathway in T2DM.

Cytochrome P450-soluble epoxide hydrolase derived linoleic acid oxylipins and cognitive performance in type 2 diabetes

Type 2 diabetes mellitus (T2DM) increases the risk of cognitive decline and dementia. Disruptions in the cytochrome P450-soluble epoxide hydrolase (CYP450-sEH) pathway have been reported in T2DM, obesity and cognitive impairment. We examine linoleic acid (LA)-derived CYP450-sEH oxylipins and cognition in T2DM and explore potential differences between obese and nonobese individuals. The study included 51 obese and 57 nonobese participants (mean age 63.0 ± 9.9, 49% women) with T2DM. Executive function was assessed using the Stroop Color-Word Interference Test, FAS-Verbal Fluency Test, Digit Symbol Substitution Test, and Trails Making Test-Part B. Verbal memory was assessed using the California Verbal Learning Test, second Edition. Four LA-derived oxylipins were analyzed by ultra-high-pressure-LC/MS, and the 12,13-dihydroxyoctadecamonoenoic acid (12,13-DiHOME) considered the main species of interest. Models controlled for age, sex, BMI, glycosylated hemoglobin A1c, diabetes duration, depression, hypertension, and education. The sEH-derived 12,13-DiHOME was associated with poorer executive function scores (F1,98 = 7.513, P = 0.007). The CYP450-derived 12(13)-epoxyoctadecamonoenoic acid (12(13)-EpOME) was associated with poorer executive function and verbal memory scores (F1,98 = 7.222, P = 0.008 and F1,98 = 4.621, P = 0.034, respectively). There were interactions between obesity and the 12,13-DiHOME/12(13)-EpOME ratio (F1,97 = 5.498, P = 0.021) and between obesity and 9(10)-epoxyoctadecamonoenoic acid (9(10)-EpOME) concentrations (F1,97 = 4.126, P = 0.045), predicting executive function such that relationships were stronger in obese individuals. These findings suggest that the CYP450-sEH pathway as a potential therapeutic target for cognitive decline in T2DM. For some markers, relationships may be obesity dependent.

Glutathione Peroxidase Activity Is Altered in Vascular Cognitive Impairment-No Dementia and Is a Potential Marker for Verbal Memory Performance

Background:

Coronary artery disease (CAD) increases risk for vascular cognitive impairment-no dementia (VCIND), a precursor to dementia, potentially through persistent oxidative stress.

Objective:

This study assessed peripheral glutathione peroxidase activity (GPX), which is protective against oxidative stress, in VCIND versus cognitively normal CAD controls (CN). GPX activity was also evaluated as a biomarker of cognition, particularly verbal memory.

Methods:

120 CAD patients with VCIND (1SD below norms on executive function or verbal memory (VM)) or without (CN) participated in exercise rehabilitation for 24 weeks. Neurocognitive and cardiopulmonary fitness (VO_2peak) assessments and plasma were collected at baseline and 24-weeks.

Results:

GPX was higher in VCIND compared to CN (F_1,119 = 3.996, p = 0.048). Higher GPX was associated with poorer baseline VM (β= –0.182, p = 0.048), and longitudinally with VM decline controlling for sex, body mass index, VO_2peak, and education (b[SE] = –0.02[0.01], p = 0.004). Only CN participants showed improved VM performance with increased fitness (b[SE] = 1.30[0.15], p < 0.005).

Conclusion:

GPX was elevated in VCIND consistent with a compensatory response to persistent oxidative stress. Increased GPX predicted poorer cognitive outcomes (verbal memory) in VCIND patients despite improved fitness.

The novel effectiveness of Tai Chi on cardiopulmonary fitness among stroke patients in the recovery phase: a study protocol for a randomized controlled trial

BACKGROUND

Stroke is the leading cause of death worldwide. China faces a similar risk of stroke as developed countries because of considerable changes in lifestyle, such as overeating and smoking. Tai Chi is a traditional form of mind-body exercise that has been widely practiced in China for thousands of years. However, there are few studies on the effect of Tai Chi on the cardiopulmonary function of stroke patients in the recovery phase. Therefore, it is necessary to observe the effect of Tai Chi on the cardiorespiratory fitness of patients after stroke.

METHODS

This is a parallel-design, two-arm, analyst assessor-blinded, randomized controlled trial. A total of 226 stroke patients in the recovery phase will be recruited and assigned randomly to a control group or Tai Chi group at a 1:1 ratio. The patients in the Tai Chi group will perform the Tai Chi exercise. The patients in the control group will perform walking exercises. Patients in both groups will receive conventional treatments and healthy education. The primary outcomes will be VO_2peak and scores on the MOS item short form health survey (SF-36) scale. Secondary outcomes will include vital capacity (VC), ejection fractions (EF), and cardiac output (CO). The assessments of the tests will be performed at three time points (before exercise, at the end of exercise, and 6 weeks after exercise). Adverse events will be recorded faithfully during the study.

DISCUSSION

If the results are positive, this study will contribute to the establishment of further guided Tai Chi rehabilitation programs.

TRIAL REGISTRATION

Chinese Clinical Trial Registry ChiCTR2000034719 . Registered on 16 July 2020.

Endostatin as a Mediator Between Endothelial Function and Cognitive Performance in Those at Risk for Vascular Cognitive Impairment

Background:

Patients with coronary artery disease have an increased risk for developing vascular cognitive impairment. Endothelial function is often diminished and has been associated with lower cognitive performance in these patients. The link between endothelial function and cognition in coronary artery disease is not fully understood. Angiogenesis may play a role in mediating the association between endothelial function and cognition since angiogenic processes rely heavily on the endothelium.

Objective:

The aim of this study was to determine if markers of angiogenesis mediate the relationship between endothelial function and cognition in coronary artery disease patients.

Methods:

In 50 participants with coronary artery disease, endothelial function was assessed using peripheral arterial tonometry. Vascular endothelial growth factor (pro-angiogenic) and endostatin (anti-angiogenic) were measured in peripheral serum samples. Cognition was assessed using the Montreal Cognitive Assessment. A mediation analysis, using a bias corrected inferential bootstrapping method with 10,000 permutations, was used to determine if vascular endothelial growth factor or endostatin mediated an association between peripheral arterial tonometry measures and cognitive performance on the Montreal Cognitive Assessment.

Results:

Endostatin, but not vascular endothelial growth factor, mediated a relationship between endothelial function and cognitive performance when controlling for total years of education, body mass index, coronary artery bypass graft, stent, diabetes, and diuretic use. This analysis was also significant when delayed recall was substituted for the overall score on the Montreal Cognitive Assessment.

Conclusion:

These results suggest that endostatin mediates an association between endothelial function and cognitive performance in coronary artery disease.

The Benefits of Physical Activity in Individuals with Cardiovascular Risk Factors: A Longitudinal Investigation Using fNIRS and Dual-Task Walking

Cardiovascular fitness is linked to better executive functions, preserved gait speed, and efficient cortical activity. Older adults with cardiovascular risk factors (CVRFs) typically show poor cognitive performance, low physical fitness, and altered brain functioning compared with healthy individuals. In the current study, the impact of regular physical activity on cognition, locomotion, and brain functions was explored in a cohort of older adults with low or high CVRFs. Cortical activation of the frontal areas was investigated using functional Near-Infrared Spectroscopy (fNIRS) at baseline, at 6 months and at 12 months. Evoked cortical response and behavioral performance were assessed using the dual-task walking paradigm, consisting of three conditions: single cognitive task (2-back task), single walking task (walking), and dual-task (2-back whilst walking). Results show greater task-related cortical response at baseline in individuals with high CVRFs compared to those with low CVRFs. Moreover, participants with high CVRFs benefitted the most from participating in regular physical activity, as their cortical response decreased at the 12-month follow-up and became comparable to that of participants with low CVRFs. These changes were observed in conjunction with improved cognitive performance and stable gait speed throughout the 12-month period in both groups. Our findings provide evidence that participation in regular physical activity may be especially beneficial in individuals with CVRFs by promoting brain and cognitive health, thus potentially contributing to prevention of cognitive decline. Future research may explore whether such effects are maintained in the long-term in order to design ad-hoc interventions in this specific population.

Randomised controlled trial in women with coronary artery disease investigating the effects of aerobic interval training versus moderate intensity continuous exercise in cardiac rehabilitation: CAT versus MICE study

BACKGROUND

The primary aim of the present study was to investigate the effects of aerobic interval training (AIT) versus moderate intensity continuous exercise (MICE) on aerobic exercise capacity (V̇O2peak), in women only, with coronary artery disease (CAD) and who were referred to a large, 24-week outpatient cardiac rehabilitation (CR) programme. Secondary objectives included comparing the effects of AIT versus MICE on cognition, cardiovascular risk profile, adherence and quality of life before and after the 24-week CR programme.

METHODS

Thirty-one postmenopausal women with CAD (left ventricular ejection fraction >35%; 68.2±9.2 years of age; V̇O2peak: 19.1±3.5 mL kg-1 min-1) were randomised to 24 weeks of usual care MICE (60%-80% of V̇O2peak, five times per week) or AIT (four 4-min intervals at 90%-95% of peak heart rate, three times per week+two times per week usual care MICE). Differences between and within groups were assessed using independent samples t-tests and paired samples t-tests, respectively. Treatment effect analysis of AIT on V̇O2peak and secondary outcomes was determined using analysis of covariance with baseline values as covariates.

RESULTS

A randomised controlled trial study design was unfeasible in this female CAD population. Unanticipated challenges in recruitment availability and eligibility, in combination with a 59% and 50% attrition rate in the AIT and MICE group, respectively, rendered this study underpowered to detect differences between groups. The per protocol treatment effect analysis, however, unveiled a 0.95 mL kg-1 min-1 improvement in V̇O2peak in response to AIT over MICE (p<0.001).

CONCLUSIONS

Further research is necessary to elucidate the patient profile and circumstances under which the potential for the implementation of AIT may be individualised, and offered in clinical practice.

TRIAL REGISTRATION

NCT02966158.

Validity of a novel screen for cognitive impairment and neuropsychiatric symptoms in cardiac rehabilitation

BACKGROUND

Currently, there is no composite screening tool that can efficiently and effectively assess prevalent yet under-recognized cognitive and neuropsychiatric comorbidities in patients with cardiovascular disease. We aimed to determine the validity and feasibility of a novel screen assessing cognitive impairment, anxiety, apathy and depression (CAAD screen) in those attending cardiac rehabilitation (CR).

METHODS

All patients diagnosed with cardiovascular disease or cardiovascular risk factors entering CR were screened as part of clinical care. A subset of those patients agreed to complete validation assessments (n = 127). Screen results were compared to widely accepted standards for cognition, anxiety, apathy, and depression using a modified receiver operating characteristic (ROC) and area under the curve analysis.

RESULTS

The screen was completed by 97% of participants in 10 min or less with an average completion time of approximately 5 min. Screening scores adjusted for age, sex and years of education had acceptable or excellent validity compared to widely accepted standard diagnoses: CAAD-Cog (AUC = 0.80); CAAD-Anx (AUC = 0.81); CAAD-Apathy (AUC = 0.79) and CAAD-Dep (AUC = 0.85).

CONCLUSIONS

The CAAD screen may be a valid and feasible tool for detecting cognitive impairment, anxiety, apathy and depression in CR settings.

Lower serum osteocalcin concentrations in patients with type 2 diabetes and relationships with vascular risk factors among patients with coronary artery disease

BACKGROUND

Lower serum concentrations of the osteoblast-derived protein, osteocalcin, have been associated with poorer glycemic control, insulin resistance and atherosclerosis, and with the development of type 2 diabetes (T2DM).

METHODS

This study compares concentrations of two physiological forms of osteocalcin, carboxylated (cOCN) and uncarboxylated (unOCN), between participants with T2DM (n = 20) and age-, gender- and body mass index (BMI)-matched participants without T2DM (n = 40) among patients with coronary artery disease (CAD), and it explores relationships between osteocalcin concentrations and cardiovascular risk factors.

RESULTS

Concentrations of unOCN (2.71 ± 1.86 vs. 4.70 ± 2.03 ng/mL; t = -3.635, p = 0.001) and cOCN (8.70 ± 2.27 vs. 10.77 ± 3.69 ng/mL; t = -2.30, p = 0.025) were lower in participants with T2DM. In participants without T2DM, concentrations of cOCN were associated with fitness (VO_2Peak rho = 0.317, p = 0.047) and lower body fat (rho = -0.324, p = 0.041). In participants with T2DM, lower unOCN was associated with HbA1c (rho = -0.516, p = 0.020). Higher body mass was associated with higher unOCN (rho = 0.423, p = 0.009) in participants without T2DM, but with lower concentrations of both unOCN (rho = -0.590, p = 0.006) and cOCN (rho = -0.632, p = 0.003) in participants with T2DM.

CONCLUSION

In patients with CAD, lower osteocalcin concentrations were related to type 2 diabetes, and to adverse fitness, metabolic and obesity profiles.

Association Between Endothelial Function and Cognitive Performance in Patients With Coronary Artery Disease During Cardiac Rehabilitation

OBJECTIVE

Subtle cognitive deficits indicating early neural risk are common in the clinical presentation of coronary artery disease (CAD). Although deterioration may be mitigated by exercise, cognitive response to exercise is heterogeneous. Vasculopathy including endothelial dysfunction is a hallmark of CAD and may play an important role in impairing neural adaptation to exercise. This study aimed to assess peripheral measurements of endothelial function as predictors of cognitive performance in CAD participants undertaking cardiac rehabilitation (CR).

METHODS

CAD patients (N = 64) undergoing CR were recruited for this prospective observational study. Neuropsychological and endothelial function assessments were performed at baseline and after 3 months of CR. Z-scores for overall cognitive performance and specific cognitive domains (verbal and visuospatial memory, processing speed, and executive function) were calculated. Endothelial function was measured by the reactive hyperemia index (RHI) using peripheral arterial tonometry. Cross-sectional and longitudinal associations between RHI and overall cognition were assessed using linear regressions and mixed models, respectively. Domain-specific associations were also explored.

RESULTS

Although lower RHI was not associated with overall cognition at baseline (b = 0.26, p = .10), an increased RHI was significantly associated with an improvement in overall cognition (b = 0.55, p = .030) over 3 months. Lower RHI was associated with poorer verbal memory (β = 0.28, p = .027) at baseline and an increased RHI over 3 months was associated with an improvement in processing speed (b = 0.42, p = .033).

CONCLUSIONS

RHI may be a clinically useful predictor of cognitive change and might provide insight into the etiology of cognitive dysfunction in patients with CAD.

Cognitive function in patients with coronary artery disease: A literature review

Objective Cognitive function impairment is a well-documented complication of cerebrovascular disease (CBVD). Less is known about what factors affect the deterioration of cognitive function in patients with coronary artery disease (CAD). The aim of this review is to explore recent studies investigating factors associated with cognitive function in patients with CAD. Methods Studies published from 2010 to 2016 were identified through a systematic search of MEDLINE/PubMed and were included if they addressed factors affecting cognitive function in the CAD population. Results Of the 227 publications identified, 32 were selected for the review. Five factors tentatively affecting cognitive function in patients with CAD were identified: coronary artery bypass grafting (CABG) surgery, apolipoprotein E4 (APOE4) genotype, left ventricular ejection fraction (LVEF), medication use, and various hormones and biomarkers. Conclusion New techniques in CABG surgery have proven to alleviate postoperative cognitive decline. Researchers are still debating the effects of APOE4 genotype, LVEF, and the use of cardiovascular medications on cognitive function. Thyroid hormones and biomarkers are associated with cognitive function, but the exact nature of the association is debatable. Longitudinal studies should clarify those associations. In addition, cross-sectional studies addressing other causes of cognitive decline in patients with CAD are warranted.

A Lipidomics Approach to Assess the Association Between Plasma Sphingolipids and Verbal Memory Performance in Coronary Artery Disease Patients Undertaking Cardiac Rehabilitation: A C18:0 Signature for Cognitive Response to Exercise

BACKGROUND

Early subtle deficits in verbal memory, which may indicate early neural risk, are common in patients with coronary artery disease (CAD). While exercise can improve cognition, cognitive response to exercise is heterogeneous. Sphingolipids have been associated with the development and progression of CAD, and impairments in sphingolipid metabolism may play roles in neurodegeneration and in the neural adaptation response to exercise.

OBJECTIVE

In this study, change in plasma concentrations of sphingolipids was assessed in relation to change in verbal memory performance and in other cognitive domains among CAD subjects undertaking a 6-month cardiac rehabilitation (CR) program.

METHODS

Patients with CAD (n = 120, mean age = 64±6 y, 84% male, years of education = 16±3) underwent CR with neuropsychological assessments and blood collected at baseline, 3-, and 6-months. Z-scores based on age, gender, and education were combined for verbal memory, visuospatial memory, processing speed, executive function, and global cognition tasks to calculate cognitive domain Z-scores. Plasma sphingolipid concentrations were measured from fasting blood samples using high performance liquid chromatography coupled electrospray ionization tandem mass spectrometry (LC/MS/MS). Mixed models were used to identify sphingolipids significantly associated with performance in verbal memory and other cognitive domains, adjusting for potential confounders.

RESULTS

A decrease in ceramide C18:0 concentration was significantly associated with improvement in verbal memory performance (b[SE] = -0.51 [0.25], p = 0.04), visuospatial memory (b[SE] = -0.44 [0.22], p = 0.05), processing speed (b[SE] = -0.89 [0.32], p = 0.007), and global cognition (b[SE] = -1.47 [0.59], p = 0.01) over 6 months of CR.

CONCLUSIONS

Plasma ceramide C18:0 concentrations may be a sensitive marker of cognitive response to exercise in patients with CAD.

Lipid Peroxidation Markers in Coronary Artery Disease Patients with Possible Vascular Mild Cognitive Impairment

This study examined associations between lipid peroxidation markers and cognition, and associations between these markers and cognitive response to an exercise intervention program, in adults with coronary artery disease at risk of dementia. Lipid peroxidation products were measured in serum in 118 patients (29 possible vascular mild cognitive impairment and 89 controls). Ratios of early- (lipid hydroperoxides, LPH) to late-stage (8-isoprostane, 8-ISO; 4-hydroxy-2-nonenal, 4-HNE) lipid peroxidation products were calculated. Cognitive performance was assessed before and at completion of a 24-week exercise intervention program. A global effect of group on lipid peroxidation markers was observed, adjusting for sex, years of education, and cardiopulmonary fitness (main effect of group F (3,102) = 2.957, p = 0.036). Lower lipid peroxidation at baseline, as determined by lower 8-ISO concentration, was associated with greater improvement in verbal memory (F (1, 64) = 4.738, p = 0.03) and executive function (F (1, 64) = 5.219, p = 0.026) performance. Similarly, higher ratios of 8-ISO/LPH (F (1, 65) = 6.592, p = 0.013) and (8-ISO+4-HNE) to LPH (F (1, 65) = 3.857, p = 0.054), were associated with less improvement in executive function performance over a 24-week exercise intervention. Lipid peroxidation may be a biomarker of early vascular cognitive impairment, and elevated lipid peroxidation might limit the cognitive benefits of exercise in this high-risk population.

Cognitive function in patients with stable coronary heart disease: Related cerebrovascular and cardiovascular responses

Chronic exercise has been shown to prevent or slow age-related decline in cognitive functions in otherwise healthy, asymptomatic individuals. We sought to assess cognitive function in a stable coronary heart disease (CHD) sample and its relationship to cerebral oxygenation-perfusion, cardiac hemodynamic responses, and V˙O2 peak compared to age-matched and young healthy control subjects. Twenty-two young healthy controls (YHC), 20 age-matched old healthy controls (OHC) and 25 patients with stable CHD were recruited. Cognitive function assessment included short term—working memory, perceptual abilities, processing speed, cognitive inhibition and flexibility and long-term verbal memory. Maximal cardiopulmonary function (gas exchange analysis), cardiac hemodynamic (impedance cardiography) and left frontal cerebral oxygenation-perfusion (near-infra red spectroscopy) were measured during and after a maximal incremental ergocycle test. Compared to OHC and CHD, YHC had higher V˙O2 peak, maximal cardiac index (CI max), cerebral oxygenation-perfusion (ΔO₂ Hb, ΔtHb: exercise and recovery) and cognitive function (for all items) (P<0.05). Compared to OHC, CHD patients had lower V˙O2 peak, CI max, cerebral oxygenation-perfusion (during recovery) and short term—working memory, processing speed, cognitive inhibition and flexibility and long-term verbal memory (P<0.05). V˙O2 peak and CI max were related to exercise cerebral oxygenation-perfusion and cognitive function (P<0.005). Cerebral oxygenation-perfusion (exercise) was related to cognitive function (P<0.005). Stable CHD patients have a worse cognitive function, a similar cerebral oxygenation/perfusion during exercise but reduced one during recovery vs. their aged-matched healthy counterparts. In the all sample, cognitive functions correlated with V˙O2 peak, CI max and cerebral oxygenation-perfusion.

Prioritizing Functional Capacity as a Principal End Point for Therapies Oriented to Older Adults With Cardiovascular Disease: A Scientific Statement for Healthcare Professionals From the American Heart Association

Adults are living longer, and cardiovascular disease is endemic in the growing population of older adults who are surviving into old age. Functional capacity is a key metric in this population, both for the perspective it provides on aggregate health and as a vital goal of care. Whereas cardiorespiratory function has long been applied by cardiologists as a measure of function that depended primarily on cardiac physiology, multiple other factors also contribute, usually with increasing bearing as age advances. Comorbidity, inflammation, mitochondrial metabolism, cognition, balance, and sleep are among the constellation of factors that bear on cardiorespiratory function and that become intricately entwined with cardiovascular health in old age. This statement reviews the essential physiology underlying functional capacity on systemic, organ, and cellular levels, as well as critical clinical skills to measure multiple realms of function (eg, aerobic, strength, balance, and even cognition) that are particularly relevant for older patients. Clinical therapeutic perspectives and patient perspectives are enumerated to clarify challenges and opportunities across the caregiving spectrum, including patients who are hospitalized, those managed in routine office settings, and those in skilled nursing facilities. Overall, this scientific statement provides practical recommendations and vital conceptual insights.

A Pilot Study: The Beneficial Effects of Combined Statin-exercise Therapy on Cognitive Function in Patients with Coronary Artery Disease and Mild Cognitive Decline

Objective Hypercholesterolemia, a risk factor in cognitive impairment, can be treated with statins. However, cognitive decline associated with "statins" (HMG-CoA reductase inhibitors) is a clinical concern. This pilot study investigated the effects of combining statins and regular exercise on cognitive function in coronary artery disease (CAD) patients with prior mild cognitive decline. Methods We recruited 43 consecutive CAD patients with mild cognitive decline. These patients were treated with a statin and weekly in-hospital aerobic exercise for 5 months. We measured serum lipids, exercise capacity, and cognitive function using the mini mental state examination (MMSE). Results Low-density lipoprotein cholesterol levels were significantly decreased, and maximum exercise capacity (workload) was significantly increased in patients with CAD and mild cognitive decline after treatment compared with before. Combined statin-exercise therapy significantly increased the median (range) MMSE score from 24 (22-25) to 25 (23-27) across the cohort (p<0.01). Changes in body mass index (BMI) were significantly and negatively correlated with changes in the MMSE. After treatment, MMSE scores in the subgroup of patients that showed a decrease in BMI were significantly improved, but not in the BMI-increased subgroup. Furthermore, the patients already on a statin at the beginning of the trial displayed a more significant improvement in MMSE score than statin-naïve patients, implying that exercise might be the beneficial aspect of this intervention as regards cognition. In a multivariate logistic regression analysis adjusted for age >65 years, sex, and presence of diabetes mellitus, a decrease in BMI during statin-exercise therapy was significantly correlated with an increase in the MMSE score (odds ratio: 4.57, 95% confidence interval: 1.05-20.0; p<0.05). Conclusion Statin-exercise therapy may help improve cognitive dysfunction in patients with CAD and pre-existing mild cognitive decline.

The Effects of Aerobic Exercise on Cognitive and Neural Decline in Aging and Cardiovascular Disease

Aging is characterized by a decline in cognitive functions, particularly in the domains of executive function, processing speed and episodic memory. These age-related declines are exacerbated by cardiovascular disease (CVD) and cardiovascular risk factors (hypertension, diabetes, obesity, elevated total cholesterol). Structural and functional alterations in brain regions, including the fronto-parietal and medial temporal lobes, have been linked to age- and CVD-related cognitive decline. Multiple recent studies indicate that aerobic exercise programs may slow the progression of age-related neural changes and reduce the risk for mild cognitive impairment as well as dementia. We review age- and CVD-related decline in cognition and the underlying changes in brain morphology and function, and then clarify the impact of aerobic exercise on moderating these patterns.

Ceramides predict verbal memory performance in coronary artery disease patients undertaking exercise: a prospective cohort pilot study

Background

Coronary artery disease (CAD) is associated with verbal memory decline, although deterioration may be mitigated in individuals undertaking exercise interventions. Ceramide sphingolipids, suggested to play a role in pathological neurodegeneration, have been associated with the development and progression of CAD but their relationship with cognitive response to exercise has not been assessed. In this study, concentrations of very long chain ceramides (C22:0 and C24:0) were assessed as predictors of changes in verbal memory performance over 1 year in subjects with CAD undertaking cardiac rehabilitation (CR).

Methods

Verbal memory was measured using the California Verbal Learning Test 2^nd Ed. (CVLT-II), from which Z-scores were calculated based on age, gender and education matched norms. Baseline plasma C22:0 and C24:0 ceramide concentrations were measured from fasting blood samples using high performance liquid chromatography coupled electrospray ionization tandem mass spectrometry (LC/MS/MS). Repeated measures general linear models were used to determine the association between baseline plasma ceramides and the change in verbal memory performance over 1 year of CR controlling for age and body mass index (BMI).

Results

In patients with CAD (n = 33, mean age = 62 ± 9 years, 84.8% male, years of education = 17 ± 3 years), higher baseline plasma C22:0 (F_{1, 29} = 5.30, p = 0.03) and C24:0 (F_{1, 29} = 4.04, p = 0.05) concentrations significantly predicted less improvement in verbal memory performance over 1 year of CR controlling for age and BMI.

Conclusions

Plasma ceramide concentrations should be further examined as potential predictors of cognitive response to exercise and worse cognitive outcomes in patients with CAD.

Trial registration

NCT01625754

Poor Aerobic Fitness May Contribute to Cognitive Decline in HIV-infected Older Adults

The HIV-infected older adult (HOA) community is particularly vulnerable to cognitive impairment. Previous studies in the general older adult population have reported that lower scores on tests of cognitive function often correlate negatively with aerobic fitness [5-7]. HIV-infected individuals have significantly reduced aerobic fitness and physical function compared to HIV-uninfected individuals. Determining important correlates of cognitive ability may be beneficial in not only detecting precursors to future cognitive impairments, but also target areas for interventions. The purpose of this study was to investigate the relationship between cognitive ability and aerobic fitness in HIV-infected older adults. We conducted a cross-sectional study of HOA on antiretroviral therapy (ART) >50 years of age. Domain specific cognitive function was assessed by means of a neuropsychological battery. Aerobic fitness (VO2peak) was assessed using a graded, progressive treadmill test. Thirty-seven HOA on ART (mean±SD: age 59±6 years, BMI 28±5, CD4 663±337 cells/ml, duration since HIV diagnosis 17±7 years; 81% males) completed the cognitive tests. Several domains of cognition were significantly associated with VO2peak by Spearman correlation analysis (p<0.05). By step-wise adjusted regression VO2peak was most frequently and significantly related to many cognitive domains such as verbal and visual memory, visual perception, and language (p<0.05). We found that participants with higher Vo2peak were less likely to have more severe forms of HIV-associated neurocognitive disorders (HAND) such as mild neurocognitive disorder (OR=0.65; p=0.01) and HIV-associated dementia (OR=0.64; p=0.0006). In HOA and in conclusion, aerobic fitness is related to cognitive performance on various tasks. The likelihood of cognitive impairment increased with lower fitness levels. Therefore, increased fitness may serve an important factor in maintenance of cognition and neural integrity for aging HIV-infected individuals. Future prospective and large scale studies are needed to evaluate the effect of fitness and vascular stiffness and function on cognition and brain structure among HOA.

Higher cortisol predicts less improvement in verbal memory performance after cardiac rehabilitation in patients with coronary artery disease

Objective. While physical activity can improve verbal memory performance in subjects with coronary artery disease (CAD), there is large variability in response. Elevated cortisol production has been suggested to negatively affect verbal memory performance, yet cortisol concentrations have not been assessed as a predictor of response to exercise intervention in those with CAD. Methods. CAD patients participating in a one-year cardiac rehabilitation program were recruited. Memory was assessed with the California Verbal Learning Test second edition at baseline and one year. Cortisol was measured from a 20 mg, 3.0 cm hair sample collected at baseline. Results. In patients with CAD (n = 56, mean ± SD age = 66 ± 11, 86% male), higher cortisol (hair cortisol concentrations ≥ 153.2 ng/g) significantly predicted less memory improvement (F_1,50 = 5.50, P = 0.02) when controlling for age (F_1,50 = 0.17, P = 0.68), gender (F_1,50 = 2.51, P = 0.12), maximal oxygen uptake (F_1,50 = 1.88, P = 0.18), and body mass index (F_1,50 = 3.25, P = 0.08). Conclusion. Prolonged hypothalamic pituitary adrenal axis activation may interfere with exercise-related improvements in memory in CAD.

The effects of an aerobic and resistance exercise training program on cognition following stroke

BACKGROUND

Cognitive benefits obtained from exercise in healthy populations support the idea that aerobic and resistance training (AT+RT) would confer benefit for poststroke recovery. However, there is little evidence regarding the effectiveness of such programs.

OBJECTIVE

To evaluate the effects of a 6-month exercise program of AT+RT on cognition in consecutively enrolled patients with motor impairments ≥10 weeks poststroke.

METHODS

Outcomes were measured before and after 6 months of AT+RT on 41 patients. Cognition was measured by the Montreal Cognitive Assessment (MoCA). Secondary measures included evaluation of gas exchange anaerobic threshold (ATge), body composition by dual energy X-ray absorptiometry, and depressive symptoms by questionnaire.

RESULTS

There were significant improvements in overall MoCA scores (22.5 ± 4.5 to 24.0 ± 3.9, P < .001) as well as in the subdomains of attention/concentration (4.7 ± 1.7 to 5.2 ± 1.3, P = .03) and visuospatial/executive function (3.4 ± 1.1 to 3.9 ± 1.1, P = .002). There was a significant reduction in the proportion of patients meeting the threshold criteria for mild cognitive impairment (MCI) at baseline compared with posttraining (65.9% vs 36.6%, P < .001). In a linear regression model, there was a positive association between change in cognitive function and change in fat-free mass of the nonaffected limbs (β = .002; P = .005) and change in attention/concentration and change in ATge (β = .383; P ≤ .001), independent of age, sex, time from stroke, and change in fat mass and depression score.

CONCLUSION

A combined training model (AT+RT) resulted in improvements in cognitive function and a reduction in the proportion of patients meeting the threshold criteria for MCI. Change in cognition was positively associated with change in fat-free mass and ATge.

Improving post-intensive care unit neuropsychiatric outcomes: understanding cognitive effects of physical activity

Critical illness and its treatment often result in long-term neuropsychiatric morbidities. Consequently, there is a need to focus on means to prevent or ameliorate these morbidities. Animal models provide important data regarding the neurobiological effects of physical activity, including angiogenesis, neurogenesis, and release of neurotrophic factors that enhance plasticity. Studies in noncritically ill patients demonstrate that exercise is associated with increased cerebral blood flow, neurogenesis, and brain volume, which are associated with improved cognition. Clinically, research in both healthy and diseased human subjects suggests that exercise improves neuropsychiatric outcomes. In the critical care setting, early physical rehabilitation and mobilization are safe and feasible, with demonstrated improvements in physical functional outcomes. Such activity may also reduce the duration of delirium in the intensive care unit (ICU) and improve neuropsychiatric outcomes, although data are limited. Barriers exist regarding implementing ICU rehabilitation in routine care, including use of sedatives and lack of awareness of post-ICU cognitive impairments. Further research is necessary to determine whether prior animal and human research, in conjunction with preliminary results from existing ICU studies, can translate into improvements for neuropsychiatric outcomes in critically ill patients. Studies are needed to evaluate biological mechanisms, risk factors, the role of pre-ICU functional level, and the timing, duration, and type of physical activity for optimal patient outcomes.

Brain derived neurotrophic factor, cardiopulmonary fitness and cognition in patients with coronary artery disease

OBJECTIVE

To assess serum brain derived neurotrophic factor (BDNF) concentrations as a correlate of cardiopulmonary fitness and as a predictor of cognitive performance in subjects with coronary artery disease (CAD).

METHODS

Serum BDNF concentrations were assayed by ELISA and fitness was assessed using a standardized exercise stress test. The Mini Mental Status Examination (MMSE), California Verbal Learning Test 2nd Ed., Stroop, Trail Making Test B and the Digit Symbol-Coding task were administered. The val66met BDNF genotype and serum interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) concentrations were determined as potential confounders.

RESULTS

In subjects with CAD (n=88; 85.2% male, mean age 62.8±10.5 yr), cardiopulmonary fitness was associated with higher serum BDNF concentrations (β=.305, p=.013). Higher serum BDNF concentrations were associated with higher MMSE scores (F(1,87)=15.406, p<.0005) and better performance on the Digit Symbol-Coding task (F(1,87)=9.620, p=.003). IL-6, TNF-α and the val66met genotype did not influence these results.

CONCLUSION

Serum BDNF concentrations were associated with cardiopulmonary fitness, psychomotor processing speed and overall cognition in subjects with CAD.

Measuring the impact of exercise on cognitive aging: methodological issues

Physical exercise and fitness have been proposed as potential factors that promote healthy cognitive aging. Support for this hypothesis has come from cross sectional, longitudinal, and intervention studies. In the present review, we discuss several methodological problems that limit the conclusions of many studies. The lack of consensus on how to retrospectively measure exercise intensity is a major difficulty for all studies that attempt to estimate lifelong impact of exercise on cognitive performance in older adults. Intervention studies have a much better capacity to establish causality, but still suffer from difficulties arising from inadequate control groups and the choice and modality of administration of cognitive measures. We argue that, while the association between exercise and preserved cognition during aging is clearly demonstrated, the specific hypothesis that physical exercise is a cause of healthy cognitive aging has yet to be validated. A number of factors could mediate the exercise-cognition association, including depression, and social or cognitive stimulation. The complex interactions among these 3 factors and the potential impact of exercise on cognition remain to be systematically studied. At this time, the best prescription for lifestyle interventions for healthy cognitive aging would be sustained physical, social, and mental activities. What remains unknown is which type of activity might be most useful, and whether everyone benefits similarly from the same interventions.