Experimental gerontology最新文献

Objective

Methods

Results

Conclusion

Ischemic stroke (IS) is a severe condition regulated by complex molecular alterations. This study aimed to identify potential nicotinamide adenine dinucleotide (NAD+) metabolism-associated diagnostic markers of IS and explore their associations with immune dynamics. Weighted Gene Co-expression Network Analysis and single-sample gene set enrichment analysis (ssGSEA) were employed to identify key gene modules on the GEO dataset (GSE16561). LASSO regression was used to identify diagnostic genes. A diagnostic model was then developed using the training dataset, and its performance was assessed using a validation dataset (GSE22255 dataset). Associations between hub genes and immune cells, immune response genes, and human leukocyte antigen (HLA) genes were assessed by ssGSEA. A regulatory network was constructed using mirBase and TRRUST databases. A total of 20 NAD+ metabolic genes exhibited noteworthy expression variations. Within the module notably associated with NAD+ metabolism, 19 specific genes were included in the diagnostic model, which was validated on the GSE22255 dataset (AUC: 0.733). There were significant disparities in immune cell populations, immune response genes, and HLA gene expression, all of which were associated with the hub genes. A regulatory network composed of 153 edges and 103 nodes was constructed. This study advances our understanding of IS by providing insights into NAD+ metabolism and gene interactions, contributing to potential diagnostic innovations in IS.

Introduction

Older adults are at risk of developing new or worsened disability when hospitalized for acute medical illness. This study is a secondary analysis of the STAND-Cph trial on the effect of a simple strength training intervention initiated during hospitalization and continued after discharge. We investigated the between-group difference in change in functional performance outcomes, the characteristics of patients who experienced a relevant effect of the intervention, and the characteristics of those who were compliant with the intervention, using an expanded sample size as protocolized.

Methods

The STAND-Cph was a randomized controlled trial conducted at a major Danish university hospital. Acutely admitted older adult patients (65+) from the Emergency Department were randomized to the intervention group receiving progressive strength training and a protein supplement during and after hospitalization (12 sessions over 4 weeks) or control group receiving usual care. The primary outcome was the de Morton Mobility Index assessed at baseline and 4 weeks after discharge. The secondary outcomes were 24-h mobility (assessed by ActivPAL accelerometers), isometric knee-extension strength, 30 s. sit-to-stand performance, and habitual gait speed.

Results

Between September 2013 and September 2018, a total of 158 patients were included and randomized to either the intervention group (N = 80; mean age 79.9 ± 7.6 years) or the control group (N = 78; mean age 80.8 ± 7.4 years). We found no significant between-group difference in change in our primary outcome (p > 0.05). Both the intention-to-treat (difference in change 0.14 Nm/kg (95 % CI 0.03;0.24), p = 0.01) and the per protocol (difference in change 0.16 Nm/kg (95 % CI 0.04;0.29), p = 0.008) analyses showed that between baseline and 4 weeks, knee-extension strength increased significantly more in the intervention group than in the control group. Also, the per protocol analysis showed that the intervention group increased their daily number of steps significantly more than the control group (difference in change 1088 steps (95 % CI 44; 2132); p = 0.04). When examining subgroups of patients, we found no significant differences neither between those who experienced a clinically relevant improvement in the de Morton Mobility Index and those who did not, nor between those who were compliant and those who were not.

Conclusion

This exploratory analysis indicates that while simple progressive strength training and protein supplementation does not improve functional performance assessed by the de Morton Mobility Index, it can benefit specific facets of physical activity and muscle strength among geriatric patients.

The reemergence of primitive reflexes (PRs) in older age is related to cognitive impairment. Currently, there are no means to prevent or slow their reappearance, but research evidence exists for their control in children. Therefore, this experiment investigated whether a 16-week special sensorimotor exercise program could benefit older adults and whether the intervention-induced changes (if any) may be associated with various indices of mental health. Of 115 adults over 60, 95 completed the study (mean age = 76.37 ± SD = 7.04 years, 22 % men). The experimental group (n = 38) showed an almost threefold decline in PRs compared to controls. In contrast, the control group (n = 57) exhibited a nearly threefold increase in PRs compared to the intervention group. Cognitive function increased in the experimental but not in the control group. Changes in PRs over the 16-week intervention were positively related to negative mental health indices (hopelessness and perceived stress) and negatively related to well-being. These findings suggest that the here-presented mild sensorimotor exercises could affect older adults' reemerging PRs and that changes in PRs are associated with mental health benefits. These results may open new research avenues toward preventing cognitive and psychological decline in older adults.

The pandemic has reinforced older adults' reliance on their homes and the concept of “aging in place”. Changes like reduced physical strength and cognitive deficit, however, have heightened the challenge of simple tasks like obstacle crossing among older adults, let alone when older adults cannot perceive the surroundings well during the nighttime. The study is, therefore, to evaluate the impact of lighting on older adults' obstacle-crossing behavior during the nighttime. Twenty-seven older adults (81 ± 6 yrs., 171 ± 12 cm, 75 ± 20 kg, 14 females) were recruited. Participants were asked to cross over the obstacle in a dark residential environment under point or line light. We found that the line light tended to (1) induce more external rotation of the trailing hip (p = 0.037) and more internal rotation of the leading ankle (p < 0.001) at leading leg liftoff; and (2) result in a more upright and erect posture during stance phase (less hip flexion, p = 0.006) and swing phase of the trailing leg (reduced pelvic flexion, p = 0.038). Postural changes induced by line light demonstrated improved body control, highlighting the influence of spatial information (horizontal & vertical directions) on crossing behavior in dark environments. The findings can provide additional evidence for the design of light systems in both retirement communities and individual homes. This is particularly important when designing built environments for the aging population, in cases where the surroundings may pose challenges such as obstructed walking, and other complex floor conditions.

Objectives

The study aimed to investigate the relationship between blood pressure (BP) levels and mortality among critically ill older adults in the intensive care unit (ICU), establish optimal BP target for this population, and assess the mediating effect of severe malnutrition on BP-related mortality.

Methods

Data were extracted from the Medical Information Mart for Intensive Care IV version 2.2 database, focusing on critically ill patients aged 80 years and older. The analysis included various BP parameters, such as systolic BP (SBP), diastolic BP (DBP), and mean arterial pressure (MAP).

Results

The study cohort comprised 14,660 critically ill patients, of whom 1558 (10.6 %) experienced ICU mortality and 2493 (17.0 %) experienced in-hospital mortality. Lower BP levels (SBP ≤ 112 mmHg; DBP ≤ 53 mmHg; MAP ≤65 mmHg), were associated with an increased risk of both ICU and in-hospital mortality. Notably, only reduced SBP levels were linked to a higher risk of 1-year mortality, with an adjusted hazard ratio 1.13 (95 % confidence interval 1.05 to 1.23). Additionally, severe malnutrition was identified as a mediator in the relationship between low BP levels and ICU mortality, with BP levels positively correlated with prognostic nutritional indexes.

Conclusion

Among critically ill older adults, lower BP levels are significantly associated with higher risks of ICU and in-hospital mortality, while reduced SBP levels are linked to 1-year mortality. These findings emphasize the importance of assessing nutritional status in older ICU patients with low BP levels to potentially mitigate mortality risk.

Background

Heart failure (HF) is a condition caused by a malfunction of the heart's pumping function. The single-point insulin sensitivity estimator (SPISE) index is a novel indicator for assessing insulin resistance in humans. However, the connection between the SPISE index and the risk of HF in the elderly is unknown. Therefore, our study aims to evaluate the connection between the SPISE index and HF in older adults.

Methods

The study was based on data collected from the 1999–2020 National Health and Nutrition Examination Survey database and included 6165 participants aged ≥60 years. The multivariable linear regression model and the smooth fitting curve model were applied to investigate the connection between the SPISE index and HF in the elderly. Furthermore, the subgroup analysis was performed to investigate the interactive factors.

Results

In this study, the mean age of the population was 69.38 years. After adjusting for all covariates, we observed that the SPISE index was inversely related to the prevalence of HF (OR = 0.87, 95 % CI = 0.80–0.94, P < 0.001) in older adults. The interaction analysis showed that the association might be affected by diabetes mellitus and smoking status. Additionally, an inflection point between the SPISE index and HF was found among older women.

Conclusions

An inverse correlation was detected between the SPISE index and HF in the elderly. This could provide new insight into the prevention and management of HF in the elderly population.

Vascular endothelial growth factor (VEGF), brain-derived neurotrophic factor (BDNF), and insulin-like growth factor-1 (IGF-1) may help the brain resist both functional and structural neurodegeneration, which is critical for maintaining cognitive and neurological health in older adults. This meta-analysis and meta-regression seek to elucidate the impact of physical activity on these biomarker levels in healthy seniors, as well as to examine the influence of several moderator factors, including age, sex, period length, and time, for the first time. The standardized mean effect metric was used to assess the influence of weights, which reflected each group's relative importance in comparison to baseline data. The study looked at potential moderating factors including age, gender, and physical activity levels. The analysis of 11 studies indicated no significant effect of physical activity on VEGF levels [0.328, CI 95 % (−0.871 to 1.52); I² = 0.00; p = 0.592; Q = 4.14]. Physical activity had a substantial impact on brain-derived neurotrophic factor (0.827, 95 % confidence interval: 0.487 to 1.16; I² = 0.00; p = 0.00; Q = 78.46), with females showing particularly notable effects (Tau² = 0.327, Tau = 0.571, I² = 80.90 %, Q = 68.05, df = 15, p = 0.00). Physical activity also had a substantial effect on insulin-like growth factor 1 (0.276, 95 % confidence interval: 0.065 to 0.487; I² = 0.00; p = 0.10; Q = 8.35), indicating that it positively influences IGF-1 levels. Overall, while physical exercise has a significant effect on BDNF and IGF-1, more research is needed to fully understand its impact on vascular endothelial growth factor and to investigate how individual characteristics may influence exercise outcomes.

Total cholesterol (TC) and the cholesterol oxidation product 27-hydroxycholesterol (27-OHC) are both increased in the elderly. Accumulating evidence has linked 27-OHC to glucose metabolism in the brain, while docosahexaenoic acid (DHA) has been shown to positively regulate the 27-OHC levels. However, it is unclear whether DHA may affect glucose metabolism in the brain by regulating 27-OHC levels. In this study, we hypothesized that DHA supplementation would modulate TC levels and reduce 27-OHC levels, thereby improving brain glucose metabolism in SAMP8 mice. The mice were assigned into the Control group and DHA dietary supplementation group. The study evaluated cholesterol levels, 27-OHC levels, and glucose metabolism in the brain. The results showed that DHA supplementation decreased serum levels of TC, low-density lipoprotein cholesterol (LDL-C), and increased levels of high-density lipoprotein cholesterol (HDL-C); and improved the glucose-corrected standardized uptake value of cortex, hippocampus, and whole brain regions in SAMP8 mice. In conclusion, supplementation of DHA could regulate the cholesterol composition and reduce the level of 27-OHC, thereby improving brain glucose metabolism in SAMP8 mice.