Cognition, function, and prevalent dementia in centenarians and near-centenarians: An individual participant data (IPD) meta-analysis of 18 studies

Healthy aging among centenarians and near-centenarians: Findings from the Georgia Centenarian Study

The Georgia Centenarian Study is one of the earliest comprehensive studies on centenarians. Based on the Georgia model of adaptation, the primary purpose of this study was to assess the health and well-being of our oldest population, with a focus on several primary adaptation areas: genetics and family longevity, environmental support, individual characteristics, cognitive and behavioral skills, health behaviors, and physical and mental health, including overall life satisfaction. The results of the three Georgia Centenarian sub-studies indicate that genetic and environmental variables play an important role in determining different levels of healthy aging, but they also highlight relevant mediating and moderating effects in a network of interrelating adaptation components.

Profiles of centenarians' functioning: linking functional and cognitive capacity with depressive symptoms

BACKGROUND

Despite most centenarians facing age-related declines in functional and cognitive capacities, the severity of these declines varies among individuals, as does the maintenance of good mental health (e.g., depressive symptoms) despite these declines. This study aims to examine this heterogeneity in centenarians from the Second Heidelberg Centenarian Study, which collected data from 112 centenarians living in Germany. In our study, we focus on a subsample of 73 centenarians who provided self-reports for our measures of interest (M age = 100.4, SD age = 0.55).

METHODS

We examined correlations between functional capacity (i.e., PADL, IADL), cognitive capacity (i.e., MMSE), and depressive symptoms (i.e., GDS), and the existence of different profiles using hierarchical clustering.

RESULTS

Higher functional capacity was related to higher cognitive capacity and to fewer depressive symptoms. Yet, higher cognitive capacity was associated with more depressive symptoms. Hierarchical clustering analysis elucidated this contradiction by identifying three profiles: low-capacity individuals (i.e., 24 individuals had low functional and cognitive capacities, with low depressive symptoms), high-capacity individuals (i.e., 33 individuals with high functional and cognitive capacities, with low depressive symptoms), and low-functional-high-cognitive-capacity individuals (i.e., 16 individuals showed low functional but high cognitive capacity, with high depressive symptoms). Our post-hoc analyses highlighted arthritis and pain as risk factors for functional dependence and depression.

CONCLUSIONS

Our findings emphasize the importance of identifying centenarian subgroups with specific resource- and risk profiles to better address their needs, and of treating pain to improve functional capacity and mental health in centenarians.

Association between Plant-based Diet and Risk of Chronic Diseases and All-Cause Mortality in Centenarians in China: A Cohort Study

Background

Numerous studies have suggested the health benefits of a plant-based dietary pattern. However, whether this dietary pattern is associated with health benefits for centenarians remains unexplored. Our study aimed to investigate the correlation between 16 widely consumed Chinese food items and the incidence rates of chronic diseases and all-cause mortality among centenarians.

Methods

We conducted a dietary survey on 3372 centenarians with an average age of 102.33 y in China. After rigorous screening, we identified 2675 centenarians, who underwent a 10-y follow-up study with all-cause mortality as the primary outcome. We developed 6 dietary patterns on the basis of the food consumption frequency of each participant. To model the impact of missing values, we employed multiple imputation methods, verifying the robustness of models.

Results

The overall plant-based diet index (PDI), healthy plant-based diet index (hPDI), unhealthy plant-based diet index (uPDI), healthy plant-based foods index (HPF), unhealthy plant-based foods index (uHPF), and animal-based foods index (AF) scores among centenarians in China were 46.95 ± 6.29, 44.43 ± 5.76, 51.09 ± 6.26, 21.63 ± 4.79, 9.91 ± 2.41, and 14.59 ± 3.58, respectively. High scores of PDI, hPDI, and HPF were associated with a lower risk of chronic diseases. In the 10-y follow-up study, 92.90% of centenarians have died. The high scores of the PDI (HRPDI = 0.81), hPDI (HRhPDI = 0.79), and HPF (HRHPF = 0.81) scores were significantly associated with a lower risk of death compared with the low scores. Conversely, the high AF score (HRAF = 1.17) was significantly associated with a higher risk of death compared with the low scores.

Conclusion

Despite the fact that a higher score in both a predominantly plant-based dietary pattern and a healthy dietary pattern can decrease the death among centenarians, not all HPFs have this effect. A higher AF predicted a higher risk of mortality, whereas higher PDI, hPDI, and HPF were associated with a lower risk of mortality among Chinese centenarians.

Absent in melanoma 2 mediates aging-related cognitive dysfunction by acting on complement-dependent microglial phagocytosis

Pattern separation (PS) dysfunction is a type of cognitive impairment that presents early during the aging process, and this deficit has been attributed to structural and functional alterations in the dentate gyrus (DG) of the hippocampus. Absent in melanoma 2 (AIM2) is an essential component of the inflammasome. However, whether AIM2 plays a role in aging-associated cognitive dysfunction remains unclear. Here, we found that PS function was impaired in aging mice and was accompanied by marked synaptic loss and increased expression of AIM2 in the DG. Subsequently, we used an AIM2 overexpression virus and mice with AIM2 deletion to investigate the role of AIM2 in regulating PS function and synaptic plasticity and the mechanisms involved. Our study revealed that AIM2 regulates microglial activation during synaptic pruning in the DG region via the complement pathway, leading to impaired synaptic plasticity and PS function in aging mice. These results suggest a critical role for AIM2 in regulating synaptic plasticity and PS function and provide a new direction for ameliorating aging-associated cognitive dysfunction.

Incidence of Alzheimer's Disease in Men with Late-Life Hypertension Is Ameliorated by FOXO3 Longevity Genotype

BACKGROUND

It is well established that mid-life hypertension increases risk of dementia, whereas the association of late-life hypertension with dementia is unclear.

OBJECTIVE

To determine whether FOXO3 longevity-associated genotype influences the association between late-life hypertension and incident dementia.

METHODS

Subjects were 2,688 American men of Japanese ancestry (baseline age: 77.0±4.1 years, range 71-93 years) from the Kuakini Honolulu Heart Program. Status was known for FOXO3 rs2802292 genotype, hypertension, and diagnosis of incident dementia to 2012. Association of FOXO3 genotype with late-life hypertension and incident dementia, vascular dementia (VaD) and Alzheimer's disease (AD) was assessed using Cox proportional hazards models.

RESULTS

During 21 years of follow-up, 725 men were diagnosed with all-cause dementia, 513 with AD, and 104 with VaD. A multivariable Cox model, adjusting for age, education, APOEɛ4, and cardiovascular risk factors, showed late-life hypertension increased VaD risk only (HR = 1.71, 95% CI = 1.08-2.71, p = 0.022). We found no significant protective effect of FOXO3 longevity genotype on any type of dementia at the population level. However, in a full Cox model adjusting for age, education, APOEɛ4, and other cardiovascular risk factors, there was a significant interaction effect of late-life hypertension and FOXO3 longevity genotype on incident AD (β= -0.52, p = 0.0061). In men with FOXO3 rs2802292 longevity genotype (TG/GG), late-life hypertension showed protection against AD (HR = 0.72; 95% CI = 0.55-0.95, p = 0.021). The non-longevity genotype (TT) (HR = 1.16; 95% CI = 0.90-1.51, p = 0.25) had no protective effect.

CONCLUSION

This longitudinal study found late-life hypertension was associated with lower incident AD in subjects with FOXO3 genotype.