Measure Of Reserve Research Articles

Assessment of myocardial perfusion reserve by czt camera compared to reference invasive microcirculation measurements

Myocardial perfusion reserve (MPR) is a validated diagnostic and prognostic value by Positron Emission Tomography (PET) scans. However, PET availability stays limited in certain countries as France. Gamma cameras with cadmium-zinc telluride detector (CZT-SPECT) are more available and allow the evaluation of this MPR. However, there is no comparison of its results with the interventional diagnostic procedure. Twenty-seven patients with suspected of epicardial or microcirculatory coronary involvement were prospectively included. All patients benefited from an evaluation of the MPR by CZT SPECT as well as an interventional diagnostic procedure with measure of the Fractionnal Flow Reserve (FFR), coronary flow reserve (CRF) and index of microcirculation resistance (IMR). Correlation between MPR and CFR was measured and sensitivity and specificity to detect severe coronary microcirculation disease (CMVD) defined by FFR > 0.8, CFR < 2 and IMR > 25. Coronary angiography was performed in 27 patients, with a complete functional evaluation (FFR, CFR, IMR) on 33 vessels. Two patients had significant stenosis (50-90% stenosis and FFR < 0.8). MPR was correlate with CRF measurement ( r = 0.41; P = 0.017). The sensitivity and specificity per patient to detect severe CMVD were 71% and 65%, respectively. Sensitivity and specificity of MPR by territory were 87% and 76% respectively. MPR was correlated with CRF and presented satisfactory diagnostic performance to discriminate, in the absence of significant stenosis, patients free from patients with severe CMVD.

Breath holding for 20 s following extended expiration is a practical, effective and robust standard when measuring cerebrovascular reactivity in healthy adults using BOLD fMRI at 3 T

Background and PurposeBOLD fMRI is becoming the preferred modality to study cerebrovascular reactivity. Amongst the vasoactive stimuli to induce it, breath holding is considered equal to other methods but both cerebrovascular reserve measures and breath holding designs lack standardization. We have systematically considered whether breath holding paradigms at short time periods are both a practical as well as equally effective and robust alternative to the elaborate CO2-inhalation in estimating cerebrovascular reactivity. Subjects, Materials and MethodsUsing BOLD fMRI, eleven healthy subjects were examined with dynamic T2*-weighted echo planar imaging at 3 T. Cerebrovascular reactivity was measured during episodes of breath holding for 10 s and 20 s, both after deep inspiration and after extended expiration, and compared to the reactivity following inhalation of an air mixture with 5% CO2-content. Results20 s breath holding challenges yielded higher reactivities represented by corresponding higher BOLD-signal changes when compared to 10 s ones, as did expiratory paradigms when compared to inspiratory ones. Mean signal changes ranged from 2% (10 s breath holding after inspiration) to 3% (20 s breath holding after expiration). The CO2-challenge yielded an about threefold higher reactivity (6%). ConclusionThe breath holding tasks evoked BOLD-signal increases which compare favorably to published data. A 20 s breath holding period appears to be ideal and is tolerated well. This experimental design is thus practical, effective and robust. To further standardize the breath holding design and the measurement of cerebrovascular reserve, controlled breathing during resting periods as well as modelling of the fMRI-signal to end-tidal CO2-levels should be employed in future studies.

MO152CORRELATION OF PERCEIVED FRAILTY WITH MEASURED FRAILTY IN AN ADULT HAEMODIALYSIS POPULATION

Background and AimsFrailty is a measure of physiological reserve and the ability to respond to physiological stress. Increasing frailty predicts adverse health outcomes in patients with end stage renal disease (ESRD) Despite this, frailty is not routinely measured in clinical practice where clinician perception of frailty is used to inform decision making.The Clinical Frailty Scale (CFS) is a clinical judgement-based score that is a useful screening tool for frailty. Increasing frailty measured by CFS is predictive of adverse outcomes in patients with advanced chronic kidney disease (CKD) including falls, worsening disability, care home admissions, hospitalizations and ultimately mortality. It has been widely used in the assessment of patients with COVID-19 to help inform decisions regarding ceiling of care.This study aimed to assess the correlation between clinician perception of frailty and frailty as measured using the CFS.MethodFrailty was assessed for all patients undergoing in centre hospital haemodialysis (n=53) in a single dialysis unit in Northern Ireland. A CFS score was calculated for all patients by a clinician who routinely uses the CFS in clinical practice. Patients with a score of 1-3 were classified as not frail, 4-5 as intermediately frail and 6-9 as frail.Nephrologists received basic education about frailty. They were then asked to categorize their patients as non-frail, intermediately frail or frail.The relationship between measured and perceived frailty was assessed using percent agreement. Participant characteristics of frail patients who were misclassified as intermediately frail or non-frail by clinicians were compared to those patients correctly classified as non-frail by clinicians. Fisher’s exact test was employed for categorical variables and t-tests were employed for pseudo normally distributed continuous variables.ResultsOf the 53 participants, the median age was 59 years (26-89). 41.5% were women. The median time on dialysis was 1.6 years.According to the CFS, 6 patients were categorised as non-frail, 30 patients as intermediately frail and 17 as frail.Among frail participants, 41% were correctly perceived as frail by their nephrologist. Among non-frail participants, 100% were correctly perceived as non-frail by their nephrologist.Among those who were frail according to the CFS, those misclassified as intermediately frail or non-frail, were younger (median age of those misclassified 49 years vs 62 years of those not mis-classified, P=0.03) but did not differ by sex (P=1), time on dialysis (P=0.39), presence of diabetes (P=0.30) or presence of vascular disease (P=1).ConclusionIn this study of adult patients undergoing chronic haemodialysis, perceived frailty correlated with measured frailty using the CFS less than 50% of the time. This suggests that clinical perception is not an accurate surrogate for frailty status in this population group. Additionally, this study suggests that younger patients with ESRD are less likely to be correctly perceived as frail. Such misclassification could influence clinical decisions for treatment, including candidacy for kidney transplantation.

Anti- Müllarian hormone (AMH) as an indicator of ovarian reserve in acne patients treated with isotretinoin

Background: Isotretinoin suppresses sebum development by inducing sebocyte apoptosis, which is induced by the expression of tumour necrosis factor-related apoptosis-inducing ligand, insulin-like growth factor binding protein-3, and neutrophil gelatinase-associated lipocalin, which is induced by isotretinoin. While apoptosis could play a role in the drug's key mechanism of action, it may also be to blame for the majority of isotretinoin's side effects, including ovarian reserve impairment. The aim of this study was to see if AMH could be used as a measure of ovarian reserve in isotretinoin-treated acne patients. The participants in this study were 66 female patients in their reproductive years who had various degrees of acne. All of the patients were chosen from the Dermatology and Andrology Department of Benha University Hospitals' outpatient clinic. The research lasted anywhere from 6 to 12 months. The average age of the patients in this study was 25 years, with a standard deviation of 6 years. There was no substantial difference in AMH before and after Isotretinoin therapy. The percentage change in AMH after treatment had no important relationship with the patients' age, Isotretinoin dosage, or treatment period. Isotretinoin has a negative impact on the ovaries, according to the findings. More research is required to gain a better understanding of this subject and to see if the effects are permanent.

Correlates of Memory and Executive Function in Middle-Aged and Older Adults in the CLSA: A Minority Stress Approach.

Maintaining cognitive function is an important component of healthy aging. There is increasing recognition that extraneous factors expedite the typical cognitive aging process. Risk factors for cognitive decline cluster around inequalities and disproportionally affect minority and vulnerable groups. Taking a minority stress approach, we examined the relationship between proxy measures of minority stress and cognitive health in a large sample of Canadians aged 45-85 years. Data were drawn from the baseline of the Canadian Longitudinal Study on Aging, a prospective cohort study. Memory (n = 36,849) and executive function (n = 36,266) were assessed using standardized assessment tools. We ran multiple linear regression models with memory and executive function as the outcomes. Explanatory variables included known correlates of cognitive health (i.e., demographic, health, and cognitive reserve) and proxy measures of minority stress (i.e., sexual orientation, race, and perceived social standing). Results were consistent with existing evidence showing that demographic and health variables were associated with cognitive performance. Modifiable health variables, walking, and fruit/vegetable consumption were associated with better cognitive performance, as were cognitive reserve and social support measures. Within the models, racial minority status was consistently associated with lower cognitive performance. As one's perceived social standing within their own community increased, so too did cognitive function. These findings identify factors that may put people at risk for cognitive decline. There is a need to support the cognitive health of racialized Canadians and members of other disadvantaged groups, while promoting health equity.

Factors affecting the accuracy and reliability of the measurement of anti-Müllerian hormone concentration in the clinic.

ObjectiveWe aimed to identify the factors that influence serum anti-Müllerian hormone (AMH) concentration measurements.MethodsWe collected serum samples between May and September 2018 and compared the effect on AMH concentration measured by ELISA of conditions including venepuncture, storage time, storage temperature, locations of the reaction microplate, and the use of the oral contraceptive pill and gonadotrophin-releasing hormone (GnRH).ResultsAMH concentration was not affected by food intake but was affected by haemolysis. It was also much higher in samples on the edge of the ELISA microtitre plate. AMH concentration increased after incubation at room temperature for 1 day, 4°C for 3 days, −20°C for 1 month and −40°C for 4 months, but no change occurred during storage at −80°C for 9 months. AMH concentration was high in patients following GnRH agonist treatment but was not affected by oral contraceptives.ConclusionsNo fasting is required prior to AMH measurement. Placement of serum samples on the edge of microtitre plates affects the results of the AMH ELISA. If serum samples cannot be assayed immediately, it is best to store them at −80°C. Basal AMH concentration cannot be used as a measure of ovarian reserve after GnRH agonist treatment.

Prognostic role of the Rockwood Clinical Frailty Scale in patients with acute heart failure:results from a single-centre retrospective cohort study

Abstract Funding Acknowledgements Type of funding sources: None. Background Acute decompensated heart failure carries a poor prognosis and places a significant burden on healthcare resources. Our ability to predict patients at high risk of deterioration is limited. The Rockwood Clinical Frailty Scale (CFS) is an established frailty screening tool that stratifies patients on a nine-point scale ranging from 1 (very well) to 9 (terminally ill) providing a useful measure of physiological reserve. CFS is used extensively for general prognostication in geriatric populations, yet its impact on mortality specifically in patients admitted with acute heart failure remains sparsely investigated. Purpose We performed a retrospective cohort study to investigate the prognostic role for CFS for short term mortality in patients admitted with acute heart failure. Methods Over a period of 16 weeks (7th January – 27th April 2020), 283 consecutive patients presenting to our hospital with signs and symptoms of acute heart failure were identified. Discharge summaries, electronic notes and shared care networks were manually searched for each patient to determine frailty score, baseline demographics, admission bloods and co-morbidity indices. Short term mortality at 30 days was recorded from electronic hospital and GP records. Univariate and multivariate Cox regression analysis was performed to identify clinical and biochemical predictors of mortality. Results In total, 283 patients were admitted with acute heart failure over the study period (mean age 81+/-10 years, 46% female. The mean CFS score was 5+/-1 and mean Charlson Comorbidity Index score 8+/-3. 15% of patients died within 30 days. On univariate analysis age, creatinine, Charlson Comorbidity Index and CFS were associated with prognosis. On multivariate analysis, only CFS was found to be an independent predictor of mortality (hazard ratio 1.36, p = 0.029). Conclusion This study demonstrates a clear relationship between increasing frailty score and short-term mortality in acute heart failure. The CFS is a rapid and easily accessible screening tool used widely throughout the UK. This work highlights its potential for use alongside other parameters in prognostication of patients presenting with acute decompensated heart failure. Further work is needed to explore the impact on longer term mortality and to determine practical implementation in this setting. Abstract Figure.

Monetary Policy Responses to Covid-19: A Comparison with the 2008 Crisis and Implications for the Future of Central Banking

ABSTRACT The policy responses of major central banks to the Covid-19 financial and economic crisis were faster, larger, and broader in scope than those in response to the 2008 global financial crisis. This article explains in detail the conventional and unconventional measures adopted by the U.S. Federal Reserve and reviews similar measures adopted by the Bank of England, the Bank of Canada, the European Central Bank and the Bank of Japan. Apart from lowering interest rates and acting as lenders of last resort to financial institutions, these central banks embraced large scale asset purchases as a core crisis fighting tool, with the corresponding expansion in balance sheet that they entail. The article connects this change in emphasis in central bank intervention to the normalization of shadow banking, or market-based financial intermediation, that happened between the two crises. Other extensions of the role of central banks made possible by the scope of the policy responses to Covid-19, including direct support to sectors beyond the financial industry, are also explored.

Intrinsic Capacity as a Determinant of Physical Resilience in Older Adults.

The traditional disease-oriented model of healthcare is inadequate to address the needs of the older population. Greater attention should be given to strategies that promote healthy aging. Recently proposed constructs of intrinsic capacity (IC) and physical resilience (PR) hold great potential to reshape geriatric medicine and aging research. These constructs accentuate the positive health attributes of older people in contrast to the popular frailty construct that is centered on functional deficits. IC was introduced by the World Health Organization (WHO) as a composite of all the physical and mental capacities. WHO has emphasized enhancement of IC throughout the life course so as to maintain functional ability in old age. PR, recently highlighted by the National Institute on Aging, is the ability to successfully cope with stressors. High levels of resilience can result in desirable clinical and functional outcomes after stressors. Therefore, it is important to understand the underlying physiology of PR and the risk factors contributing to diminished PR. The main goal of this article is to explore the potential relationship between IC and PR. Based on a classical theory of aging, we postulate that IC is a determinant of PR and is also a high-level integrative measure of physiologic reserve which is the fundamental factor underlying one’s ability to withstand stressors. A major implication of our postulates is that even though IC is only one of the many determinants of PR, it could serve as an important intervenable target for enhancing resilience in older adults.

Evaluation of Ecological Impact of Wind Power Project on Nature Reserve and Mitigation Compensation Measures

Evaluation of Ecological Impact of Wind Power Project on Nature Reserve and Mitigation Compensation Measures

A framework for identification of a resting-bold connectome associated with cognitive reserve

The concept of cognitive reserve proposes that specific life experiences result in more flexible or resilient cognitive processing allowing some people to cope better with age- or disease-related brain changes than others. Imaging studies seeking to understand the neural implementation of cognitive reserve have most often used task-related fMRI studies. Using that approach, we recently described a task-invariant cognitive-reserve network whose expression correlated with IQ and that moderated between cortical thickness and cognitive performance. Here we sought to identify a pattern of resting BOLD connectivity related to cognitive reserve. We identified a connectome pattern whose connectivity correlated with IQ in both the derivation sample and a separate replication sample. The majority of the edges showing positive relationships with IQ implicate frontal regions. In the derivation sample, connectivity either moderated the relationship between mean cortical thickness and a set of cognitive outcomes or accounted for unique variance in cognitive performance after accounting for cortical thickness. In a replication sample we found that expression of this connectome correlated significantly with the primary endpoint of IQ, and also accounted for unique variance in cognitive performance beyond cortical thickness. Our findings represent an intermediate level of replication and are unlikely to have arisen purely by type-I error. This connectivity pattern therefore meets some of our theoretical criteria for a cognitive reserve-related network and provides insight into the neural implementation of cognitive reserve. Further, expression of this connectome could potentially be used as a direct measure of cognitive reserve, and as an outcome measure for intervention studies that seek to influence cognitive reserve. Future validation of and re-derivation of the pattern in expanded data sets by our and other groups will lead to further improved estimates of cognitive reserve in resting functional connectivity.

Exercise right ventricular ejection fraction predicts right ventricular contractile reserve

Right ventricular (RV) contractile reserve shows promise as an indicator of occult RV dysfunction in pulmonary vascular disease. We investigated which measure of RV contractile reserve during exercise best predicts occult RV dysfunction and clinical outcomes. We prospectively studied RV contractile reserve in 35 human subjects referred for right heart catheterization for known or suspected pulmonary hypertension. All underwent cardiac magnetic resonance imaging, echocardiography, and supine invasive cardiopulmonary exercise testing with concomitant RV pressure-volume catheterization. Event-free survival was prospectively adjudicated from time of right heart catheterization for a 4-year follow-up period. RV contractile reserve during exercise, as measured by a positive change in end-systolic elastance (Ees) during exertion, was associated with elevation in pulmonary pressures but preservation of RV volumes. Lack of RV reserve, on the other hand, was tightly coupled with acute RV dilation during exertion (R2 = 0.76, p< 0.001). RV Ees and dilation changes each predicted resting RV-PA dysfunction. RV ejection fraction during exercise, which captured exertional changes in both RV Ees and RV dilation, proved to be a robust surrogate for RV contractile reserve. Reduced exercise RV ejection fraction best predicted occult RV dysfunction among a variety of resting and exercise RV measures, and was also associated with clinical worsening. RV ejection fraction during exercise, as an index of RV contractile reserve, allows for excellent identification of occult RV dysfunction, more so than resting measures of RV function, and may predict clinical outcomes as well.

Comparison of Education and Episodic Memory as Modifiers of Brain Atrophy Effects on Cognitive Decline: Implications for Measuring Cognitive Reserve

This study compared the level of education and tests from multiple cognitive domains as proxies for cognitive reserve. The participants were educationally, ethnically, and cognitively diverse older adults enrolled in a longitudinal aging study. We examined independent and interactive effects of education, baseline cognitive scores, and MRI measures of cortical gray matter change on longitudinal cognitive change. Baseline episodic memory was related to cognitive decline independent of brain and demographic variables and moderated (weakened) the impact of gray matter change. Education moderated (strengthened) the gray matter change effect. Non-memory cognitive measures did not incrementally explain cognitive decline or moderate gray matter change effects. Episodic memory showed strong construct validity as a measure of cognitive reserve. Education effects on cognitive decline were dependent upon the rate of atrophy, indicating education effectively measures cognitive reserve only when atrophy rate is low. Results indicate that episodic memory has clinical utility as a predictor of future cognitive decline and better represents the neural basis of cognitive reserve than other cognitive abilities or static proxies like education.

Single-neuron dynamical effects of dendritic pruning implicated in aging and neurodegeneration: towards a measure of neuronal reserve

Aging is a main risk factor for neurodegenerative disorders including Alzheimer's disease. It is often accompanied by reduced cognitive functions, gray-matter volume, and dendritic integrity. Although age-related brain structural changes have been observed across multiple scales, their functional implications remain largely unknown. Here we simulate the aging effects on neuronal morphology as dendritic pruning and characterize its dynamical implications. Utilizing a detailed computational modeling approach, we simulate the dynamics of digitally reconstructed neurons obtained from Neuromorpho.org. We show that dendritic pruning affects neuronal integrity: firing rate is reduced, causing a reduction in energy consumption, energy efficiency, and dynamic range. Pruned neurons require less energy but their function is often impaired, which can explain the diminished ability to distinguish between similar experiences (pattern separation) in older people. Our measures indicate that the resilience of neuronal dynamics is neuron-specific, heterogeneous, and strongly affected by dendritic topology and the position of the soma. Based on the emergent neuronal dynamics, we propose to classify the effects of dendritic deterioration, and put forward a topological measure of “neuronal reserve” that quantifies the resilience of neuronal dynamics to dendritic pruning. Moreover, our findings suggest that increasing dendritic excitability could partially mitigate the dynamical effects of aging.

Сучасний погляд на протоколи контрольованої стимуляції яєчників у жінок репродуктивного віку з різним оваріальним резервом

Reproductology is one of the most dynamically developing branches of modern medical science. It becomes especially important in the context of changes of recent years in society, the main of which is the postponement of childbirth compared to previous generations. In addition, such an important and multifactorial problem as infertility encourages scientists to find different ways to overcome it, taking into account the number of etiological factors and different initial reproductive potential of each member of the couple. In vitro fertilization (IVF) can comprehensively solve the problem, as the procedure involves the reconstruction of the process of fertilization under the supervision of the specialist, «bypassing» the critical points that are often affected by pathological processes in male or female organism. One of the main parameters that determines the prospects of using of these assisted reproductive technologies and, in fact, the strategy of IVF cycles, is ovarian reserve, which characterizes the functional ability of the ovary to generate a follicle independently / in response to exogenous influences. In recent decades, many methods have been proposed to assess it and to predict the so-called poor, «bad» ovarian response to stimulation. It goes in accordance with the fact that for patients with reduced ovarian reserve, it is advisable to use adapted schemes of controlled ovarian hyperstimulation (COH), which takes into account the main pathophysiological properties of folliculogenesis in this category of women. Numerous studies show different data on the effectiveness of gonadotropic hormones (gonadotropins, HT) of different origin in women with different ovarian reserve. This article highlights modern ideas about controlled ovarian hyperstimulation using gonadotropic hormones of various origins, demonstrates the main clinical aspects of implementation of available markers of reduced ovarian reserve, analyzes data on the effectiveness of administration of gonadotropin of different origin in patients with different ovarian reserve and possible measures to increase the efficiency of IVF cycles in patients with reduced ovarian reserve. Keywords: in vitro fertilization, controlled ovarian hyperstimulation, ovarian reserve, gonadotropins.

Dynamic frailty: Objective physiological assessment to guide management in necrotizing pancreatitis

BackgroundPhysical frailty as a measure of physiological reserve is an important yet understudied topic in necrotizing pancreatitis. We measured frailty metrics in patients with necrotizing pancreatitis at baseline and at 1 month to assess dynamic change. We hypothesized that greater baseline frailty and steeper decline in frailty biomarkers are associated with worse outcomes in necrotizing pancreatitis. MethodsA retrospective analysis of an institutional, necrotizing pancreatitis-specific database was performed. First order outcomes were organ failure, infected necrosis, step-up approach failure, and mortality. Baseline frailty assessment included measurement of comorbid diseases (modified frailty index), nutritional status (prognostic nutritional index), and radiologic sarcopenia (psoas muscle index, Hounsfield unit average calculation). Dynamic frailty was evaluated using psoas muscle index and Hounsfield unit average calculation. Significant associations between baseline and dynamic frailty with outcomes were analyzed. ResultsThree hundred and forty-one patients were included in this study. Most patients were male (65%) with biliary etiology of necrotizing pancreatitis (46%). Baseline comorbid diseases and baseline sarcopenia were not associated with first order outcomes. Lower baseline prognostic nutritional index was associated with organ failure (P < .001) and infected necrosis (P < .001). After 30 days, 25% of patients became sarcopenic. Larger declines in all sarcopenia metrics were associated with organ failure, infected necrosis, and/or death (P < .05). Lower psoas area and density were independent risk factors for organ failure and infected necrosis. ConclusionDynamic changes in sarcopenia-focused frailty metrics were significantly and consistently associated with organ failure, infected necrosis, and death. Further development of a dynamic frailty index to objectively guide decision-making in necrotizing pancreatitis is warranted.

Validation of composite proxy measures of cognitive reserve: What can longitudinal cohorts tell us about the association between modifiable dementia risk factors and the ageing

Validation of composite proxy measures of cognitive reserve: What can longitudinal cohorts tell us about the association between modifiable dementia risk factors and the ageing

Effect‐modifying role of education and crystalized intelligence on the association of amyloid pathology and cognitive function

AbstractBackgroundCognitive reserve factors reflecting innate (crystallized intelligence) and derived (educational attainment) cognitive capacity are shown to be associated with preservation of cognitive function and delayed decline. Yet little information is available on how these static measures of reserve themselves are associated with cerebral amyloid burden and influence its effect on neurocognitive performance.MethodsIn the deeply‐phenotyped CHARIOT:PRO substudy, 501 cognitively healthy individuals aged 60‐85 years had available information on ApoE genotype (carrier vs non‐carrier), brain PET‐scan/CSF‐derived amyloid load (positive vs negative), education attainment, premorbid intelligence measured by the National Adult Reading Test (NART), and cognitive performance via the multi‐domain Repeatable Battery Assessment of Neuropsychological Status (RBANS) measured at two time‐points (average 3.5 months apart). Linear mixed models were used to independently examine the effect modifying role of education and intelligence as measures of cognitive reserve on the association of amyloid status and cognitive function.ResultsThere was an effect modification in the association of amyloid status and global cognition (total RBANS score) by both intelligence and Education in mutually adjusted models accounting for age, sex and ApoE. The effect modification was more pronounced for intelligence. RBANS total score was lower in participants who were amyloid positive (vs negative) among those with lower than median intelligence quotient (mean difference in RBANS Z‐score by amyloid status ‐0.2 (95% CI ‐0.35, ‐0.04)). The inverse association between amyloid positivity and global cognition disappeared among those with higher than median intelligence (mean difference in RBANS Z‐score by amyloid status 0.01 (95% CI ‐0.16, 0.18)), P‐value for interaction &lt;0.001. Correspondingly, mean difference in RBANS Z‐score for amyloid positivity (vs negativity) was ‐0.18 (95% CI ‐0.36, 0.00) for participants with below median education, and ‐0.07 (95% CI ‐0.24, 0.09) for participants with above median education attainment, P‐value for interaction 0.19. Further adjustment for body mass index, smoking, physical activity, systolic blood pressure and diabetes did not have a remarkable effect on the findings.ConclusionsOur results support the hypothesis that although education and intelligence are both associated with higher cognitive reserve, crystalized intelligence provides more resilience against the neurodegenerative effect of amyloid pathology on global cognition.

Validation of composite proxy measures of cognitive reserve

AbstractBackgroundCognitive reserve (CR) enables individuals to maintain cognitive function despite the presence of brain pathology or atrophy [1]. CR is typically measured via proxy variables that reflect exposure to lifetime experiences, such as education [2]. Composite measures of multiple proxies combine contributions from several experiences and display consistent positive relationships with cognitive function [3]. However, the optimal set of proxies for inclusion in composite measures remains to be determined [2]. Here, we aimed to identify a combination of proxies that best reflects the ability to maintain cognitive function despite cortical thinning.MethodAs part of a larger analysis, 277 healthy adult participants provided data for this study (mean age = 69.18, SD age = 6.66, 141 females). Global cognition was defined as average of z‐scores from the Animal Naming task, Colour Trails Test 1 and 2, Immediate and Delayed Recall. Mean cortical thickness was calculated using FreeSurfer using a previously reported method [4]. CR proxies were: educational attainment, occupational complexity, premorbid intelligence, social engagement, cognitively stimulating activity, leisure activity, and physical activity. For each composite, a three‐step hierarchical‐multiple regression was performed to predict global cognition. Independent variables in Step 1 were age, gender, cortical thickness, CR composite was added in Step 2, and an interaction term (cortical thickness*composite) was further added in Step 3. Positive associations between CR composites and global cognition – independent of age, gender and cortical thickness – were ranked on significant R‐squared change values from Step 1 to Step 2. Moderation effects were identified by significant R‐squared change values from Step 2 to Step 3.ResultMost CR composites had positive associations with global cognition, independent of age, gender, and cortical thickness (see Figure 1). A CR composite measuring cognitively stimulating activity, leisure activity, and physical activity had the biggest negative moderation effect (R2 change = 0.013, p = 0.0276) on the cortical thickness‐global cognition relationship.ConclusionA composite measure of cognitively stimulating‐, leisure‐, and physical‐activity, displays construct validity as a measure of CR in addition to a wide range of composites which display positive, independent, associations with cognitive function.

Testing and interpreting measures of ovarian reserve: a committee opinion

Ovarian reserve is defined as the number of oocytes remaining in the ovary, or oocyte quantity (oocyte number). Markers of ovarian reserve include hormone levels and sonographically measured features of the ovaries. These markers can be useful as predictors of oocyte yield following controlled ovarian stimulation and oocyte retrieval. However, they are poor predictors of reproductive potential independently from age. This document replaces the document of the same name last published in 2012 (Fertil Steril 2012;98:1407-15).