Longitudinal Effects of Physical Activity Change on Hippocampal Volumes over up to 12 Years in Middle and Older Age Community-Dwelling Individuals

The objectives of this study were to investigate the long-term associations between changes in physical activity levels and hippocampal volumes over time, while considering the influence of age, sex, and APOE-ε4 genotype. We investigated the effects of change in physical activity on hippocampal volumes in 411 middle age (mean age = 47.2 years) and 375 older age (mean age = 63.1 years) adults followed up to 12 years. An annual volume decrease was observed in the left (middle age: 0.46%; older age: 0.51%) but not in the right hippocampus. Each additional 10 metabolic equivalents (METs, ~2 h of moderate exercise) increase in weekly physical activity was associated with 0.33% larger hippocampal volume in middle age (equivalent to ~1 year of typical aging). In older age, each additional MET was associated with 0.05% larger hippocampal volume; however, the effects declined with time by 0.005% per year. For older age APOE-ε4 carriers, each additional MET was associated with a 0.10% increase in hippocampal volume. No sex effects of physical activity change were found. Increasing physical activity has long-term positive effects on hippocampal volumes and appears especially beneficial for older APOE-ε4 carriers. To optimize healthy brain aging, physical activity programs should focus on creating long-term exercise habits.

Midlife susceptibility to the effects of poor diet on diabetes risk

OBJECTIVE

Type 2 diabetes mellitus (T2D) prevalence continues to increase, and age of incidence continues to decrease. More information is needed to target interventions to the ages where they can be most effective. The objective of this study was to explore the degree to which the association between diet and T2D incidence changes through adulthood.

METHODS

Participants were a large number (N = 2818) of community living adults in Canberra and Queanbeyan, Australia across three cohorts; young (20-24 followed to 32-36), mid-life (40-44 followed to 52-56) and late-life (60-64 followed to 72-76). Self-report dietary pattern scores at baseline and diabetes incidence across 12 years follow-up were measured, alongside confounders of caloric intake, sex, smoking status, years of education, hypertension, BMI and physical activity.

RESULTS

Cox proportional hazards indicated that neither Western nor Prudent dietary pattern scores were significantly associated with T2D incidence when confounders were included in the model. Unadjusted estimates suggested a positive association between Western dietary pattern scores and subsequent diabetes incidence (HR = 1.40, 95% CI [1.18, 1.64]). Compared with the mid-life cohort, a higher Western dietary pattern score posed a lower risk for incident T2D in the young cohort (unadjusted HR = 0.46, 95% CI [0.22, 0.96]), who also had significantly lower BMI and higher physical activity. No such significant effects were found for the late-life cohort.

CONCLUSIONS

Our findings indicate that mid-life may be a period of heightened vulnerability to the effects of an unhealthy diet on diabetes risk, but this effect is attenuated when risk factors related to diet, such as adiposity, are taken into account.

Prevalence of Diabetes Mellitus and Its Associated Factors in Bangladesh: Application of Two-level Logistic Regression Model

This study intends to explore the prevalence of diabetes mellitus (DM) and its associated factors in Bangladesh. The necessary information was extracted from Bangladesh Demographic and Health Survey (BDHS) 2011. In bivariate analysis, Chi-square test was performed to assess the association between selected covariates and diabetes status. A two-level logistic regression model with a random intercept at each of the individual and regional level was considered to identify the risk factors of DM. A total of 7,535 individuals were included in this study. From the univariate analysis, the prevalence of DM was found to be 33.3% in 50-54 age group for instance. In bivariate setup, all the selected covariates except sex of the participants were found significant for DM (p < 0.05). According to the two-level logistic regression model, the chance of occurring DM increases as age of the participants' increases. It was observed that female participants were more likely to have DM. The occurrence of DM was 62% higher for higher educated participants, 42% higher for the individuals who came from rich family and 63% higher for the individuals having hypertension. The chance of developing diabetes among overweighed people was almost double. However, the individuals engaged in physical work had less chance to have DM. This study calls for greater attention of government and other concerned entities to come up with appropriate policy interventions to lower the risk of DM.

Mapping the Literature on Nutritional Interventions in Cognitive Health: A Data-Driven Approach

Manual review of the extensive literature covering nutrition-based lifestyle interventions to promote healthy cognitive ageing has proved educational, however, data-driven techniques can better account for the large size of the literature (tens of thousands of potentially relevant publications to date) and interdisciplinary nature, where relevant publications may be found. In this study, we present a new way to map the literature landscape, focusing on nutrition-based lifestyle interventions to promote healthy cognitive ageing. We applied a combination of citation network analysis and text mining to map out the existing literature on nutritional interventions and cognitive health. Results indicated five overarching clusters of publications, which could be further deconstructed into a total of 35 clusters. These could be broadly distinguished by the focus on lifespan stages (e.g., infancy versus older age), and specificity regarding nutrition (e.g., a narrow focus on iodine deficiency versus a broad focus on weight gain). Rather than concentrating into a single cluster, interventions were present throughout the majority of the research. We conclude that a data-driven map of the nutritional intervention literature can benefit the design of future interventions, by highlighting topics and themes that could be synthesized across currently disconnected clusters of publications.