Working memory in older adults declines with age, but is modulated by sex and education

Working memory (WM), which underlies the temporary storage and manipulation of information, is critical for multiple aspects of cognition and everyday life. Nevertheless, research examining WM specifically in older adults remains limited, despite the global rapid increase in human life expectancy. We examined WM in a large sample (N=754) of healthy older adults (aged 58-89) in a non-Western population (Chinese speakers) in Taiwan, on a digit n-back task. We tested the influence not only of age itself and of load (1-back vs. 2-back), but also effects of both sex and education, which have been shown to modulate WM abilities. Mixed-effects regression revealed that, within older adulthood, age negatively impacted WM abilities (with linear, not nonlinear, effects), as did load (worse performance at 2-back). In contrast, education level was positively associated with WM. Moreover, both age and education interacted with sex. With increasing age, males showed a steeper WM decline than females; with increasing education, females showed greater WM gains than males. Together with other findings, the evidence suggests that age, sex, and education all impact WM in older adults, but interact in particular ways. The results have both basic research and translational implications, and are consistent with particular benefits from increased education for women

Objective sleep duration and health in elderly Russians

Objectives - We examine the relationship between sleep duration and health in the high mortality context of Russia. Methods - Night and daytime sleep durations are based on self-reports and 24-hour heart rate trends (Holter monitoring). The sample of 201 individuals (Holter data for 185) is drawn from the Moscow Lipid Research Clinics cohort, followed up since 1975-77. Field-work occurred in 2002-03. Results - Although objective and reported mean sleep are similar, there are significant intra-individual differences. Significant associations are found between objective sleep and health: longer sleep corresponds to lower grip strength, poorer self-rated health and immediate recall, and higher mortality risk score. No significant relationships are found for subjective sleep. Conclusions - We provide the first evidence of an association between long sleep and worse health outcomes among elderly Russians. Predictive power increases if objective sleep measures are used, a consideration which is especially important in small studies.

The interactive effect of change in perceived stress and trait anxiety on vagal recovery from cognitive challenge

The present study tested the hypothesis that the change in state negative affect (measured as perceived stress) after cognitive challenge moderates the relationship of trait anxiety and anger to vagal recovery from that challenge. Cardiac vagal control (assessed using heart rate variability) and respiratory rate were measured in a sample of 905 participants from the Midlife in the United States Study. Cognitive challenges consisted of computerized mental arithmetic and Stroop color–word matching tasks. Multiple regression analyses controlling for the effects of the demographic, lifestyle, and medical factors influencing cardiac vagal control showed a significant moderating effect of change in perceived stress on the relationship of trait anxiety to vagal recovery from cognitive challenges (Beta = .253, p = .013). After adjustment for respiratory rate, this effect became marginally significant (Beta = .177, p = .037). In contrast, for the relationship of trait anger to vagal recovery, this effect was not significant either before (Beta = .141, p = .257) or after (Beta = .186, p = .072) adjusting for respiratory rate. Secondary analyses revealed that among the individuals with higher levels of trait anxiety, greater reductions in perceived stress were associated with greater increases in cardiac vagal control after the challenge. In contrast, among the individuals with lower levels of trait anxiety, changes in perceived stress had no impact on vagal recovery. Therefore, change in perceived stress moderates the relationship of trait anxiety, but not trait anger, to vagal recovery from cognitive challenge

Cardiovascular Variability, Sociodemographics, and Biomarkers of Disease: The MIDUS Study

Introduction: Like heart rate, blood pressure (BP) is not steady but varies over intervals as long as months to as short as consecutive cardiac cycles. This blood pressure variability (BPV) consists of regularly occurring oscillations as well as less well-organized changes and typically is computed as the standard deviation of multiple clinic visit-to-visit (VVV-BP) measures or from 24-h ambulatory BP recordings (ABPV). BP also varies on a beat-to-beat basis, quantified by methods that parse variation into discrete bins, e.g., low frequency (0.04–0.15 Hz, LF). However, beat-to-beat BPV requires continuous recordings that are not easily acquired. As a result, we know little about the relationship between LF-BPV and basic sociodemographic characteristics such as age, sex, and race and clinical conditions. Methods: We computed LF-BPV during an 11-min resting period in 2,118 participants in the Midlife in the US (MIDUS) study. Results: LF-BPV was negatively associated with age, greater in men than women, and unrelated to race or socioeconomic status. It was greater in participants with hypertension but unrelated to hyperlipidemia, hypertriglyceridemia, diabetes, elevated CRP, or obesity. LF-diastolic BPV (DBPV), but not-systolic BPV (SBPV), was negatively correlated with IL-6 and s-ICAM and positively correlated with urinary epinephrine and cortisol. Finally, LF-DBPV was negatively associated with mortality, an effect was rendered nonsignificant by adjustment by age but not other sociodemographic characteristics. Discussion: These findings, the first from a large, national sample, suggest that LF-BPV differs significantly from VVV-BP and ABPV. Confirming its relationship to sociodemographic risk factors and clinical outcomes requires further study with large and representative samples

Heart Rate Recovery After Cognitive Challenge Is Preserved With Age

Objective: To investigate the effect of age on heart rate recovery (HRR) from cognitive challenge. Background: Aging is an independent risk factor for the development of cardiovascular disease. HRR from exercise is an established predictor of cardiac morbidity and mortality, and evidence suggests that HRR from cognitive challenge is predictive of cardiac morbidity as well. Aging is associated with delayed HRR from exercise stress, but little is known about the effect of aging on HRR from psychological stress. We tested the hypothesis that age would be related to delayed HRR from psychological stress. Methods: HRR post exposure to cognitive challenge (mental arithmetic and Stroop) was investigated in a sample of 436 participants aged 35 to 84 years in MIDUS II, a national study of health and well-being. HRR was measured as 1) the amount of change from the stress level; 2) time to recover; and 3) the area under the curve. The analyses were controlled for medical comorbidities and medications that influence HR, such as body mass index, smoking, sex, menopausal status, and amount of physical activity/exercise. Results: There was no effect for age on HRR as evaluated by all three recovery assessment methods. Conclusions: Contrary to expectation and in contrast to findings concerning HRR from exercise, HRR from cognitive challenge was preserved with age. These findings require further inquiry into differential mechanism(s) underlying HRR from psychological versus exercise stress, including any role for improved emotion regulation with greater age

Predicting Survival from Telomere Length versus Conventional Predictors: A Multinational Population-Based Cohort Study

Telomere length has generated substantial interest as a potential predictor of aging- related diseases and mortality. Some studies have reported significant associations, but few have tested its ability to discriminate between decedents and survivors compared with a broad range of well-established predictors that include both biomarkers and commonly collected self-reported data. Our aim here was to quantify the prognostic value of leuko- cyte telomere length relative to age, sex, and 19 other variables for predicting five-year mortality among older persons in three countries. We used data from nationally represen- tative surveys in Costa Rica (N = 923, aged 61+), Taiwan (N = 976, aged 54+), and the U. S. (N = 2672, aged 60+). Our study used a prospective cohort design with all-cause mor- tality during five years post-exam as the outcome. We fit Cox hazards models separately by country, and assessed the discriminatory ability of each predictor. Age was, by far, the single best predictor of all-cause mortality, whereas leukocyte telomere length was only somewhat better than random chance in terms of discriminating between decedents and survivors. After adjustment for age and sex, telomere length ranked between 15th and 17th (out of 20), and its incremental contribution was small; nine self-reported variables (e.g., mobility, global self-assessed health status, limitations with activities of daily living, smoking status), a cognitive assessment, and three biological markers (C-reactive protein, serum creatinine, and glycosylated hemoglobin) were more powerful predictors of mortality in all three countries. Results were similar for cause-specific models (i.e., mortality from cardiovascular disease, cancer, and all other causes combined). Leukocyte telomere length had a statistically discernible, but weak, association with mortality, but it did not predict survival as well as age or many other self-reported variables. Although telomere length may eventually help scientists understand aging, more powerful and more easily obtained tools are available for predicting survival.National Institute on AgingEunice Kennedy Shriver National Institute of Child Health and Human DevelopmentWellcome TrustUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Sociales::Centro Centroamericano de Población (CCP

Socioeconomic Status and Biological Markers of Health: An Examination of Adults in the United States and Taiwan

Abstract Objective:The study documents whether socioeconomic status (SES) differentials in biological risk are more widely observed and larger in the United States than Taiwan. Method: Data come from the Social Environment and Biomarkers of Aging Study in Taiwan and the Midlife in the United States study. We use regression analyses to test whether four summary measures of biological risk are significantly related to categorical measures of education, income, and subjective social status among four country-sex-specific subgroups. Results: Physiological dysregulation is significantly, negatively related to SES in both the United States and Taiwan, especially for males. The prevalence and magnitude of the relationships are similar in the two countries: 12 of 24 possible SES-biological summary score relationships are significant in the United States and 11 of 24 are significant in Taiwan. Discussion: Overall, SES differentials in biological risk do no

Microbial−mammalian cometabolites dominate the age-associated urinary metabolic phenotype in Taiwanese and American populations

Understanding the metabolic processes associated with aging is key to developing effective management and treatment strategies for age-related diseases. We investigated the metabolic profiles associated with age in a Taiwanese and an American population. 1H NMR spectral profiles were generated for urine specimens collected from the Taiwanese Social Environment and Biomarkers of Aging Study (SEBAS; n = 857; age 54–91 years) and the Mid-Life in the USA study (MIDUS II; n = 1148; age 35–86 years). Multivariate and univariate linear projection methods revealed some common age-related characteristics in urinary metabolite profiles in the American and Taiwanese populations, as well as some distinctive features. In both cases, two metabolites—4-cresyl sulfate (4CS) and phenylacetylglutamine (PAG)—were positively associated with age. In addition, creatine and β-hydroxy-β-methylbutyrate (HMB) were negatively correlated with age in both populations (p < 4 × 10–6). These age-associated gradients in creatine and HMB reflect decreasing muscle mass with age. The systematic increase in PAG and 4CS was confirmed using ultraperformance liquid chromatography–mass spectrometry (UPLC–MS). Both are products of concerted microbial–mammalian host cometabolism and indicate an age-related association with the balance of host–microbiome metabolism

Collaborative meta-analysis finds no evidence of a strong interaction between stress and 5-HTTLPR genotype contributing to the development of depression

The hypothesis that the S allele of the 5-HTTLPR serotonin transporter promoter region is associated with increased risk of depression, but only in individuals exposed to stressful situations, has generated much interest, research, and controversy since first proposed in 2003. Multiple meta-analyses combining results from heterogeneous analyses have not settled the issue. To determine the magnitude of the interaction and the conditions under which it might be observed, we performed new analyses on 31 datasets containing 38 802 European-ancestry subjects genotyped for 5-HTTLPR and assessed for depression and childhood maltreatment or other stressful life events, and meta-analyzed the results. Analyses targeted two stressors (narrow, broad) and two depression outcomes (current, lifetime). All groups that published on this topic prior to the initiation of our study and met the assessment and sample size criteria were invited to participate. Additional groups, identified by consortium members or self-identified in response to our protocol (published prior to the start of analysis1) with qualifying unpublished data were also invited to participate. A uniform data analysis script implementing the protocol was executed by each of the consortium members. Our findings do not support the interaction hypothesis. We found no subgroups or variable definitions for which an interaction between stress and 5-HTTLPR genotype was statistically significant. In contrast, our findings for the main effects of life stressors (strong risk factor) and 5-HTTLPR genotype (no impact on risk) are strikingly consistent across our contributing studies, the original study reporting the interaction, and subsequent meta-analyses. Our conclusion is that if an interaction exists in which the S allele of 5-HTTLPR increases risk of depression only in stressed individuals, then it is not broadly generalizable, but must be of modest effect size and only observable in limited situations