A retrospective analysis of serious adverse events and deaths in U.S.-based lifestyle clinical trials for cognitive health

Objective

This retrospective analysis examined serious adverse events (SAEs) and deaths in U.S. lifestyle clinical trials aimed at enhancing cognitive health in older adults.

Methods

Data was gathered from trials completed between January 1, 2000, and July 19, 2023, via ClinicalTrials.gov's API.

Results

Among these trials, 76% did not report results. The remaining studies fell into four intervention categories: Cognitive/Behavioral, Exercise/Movement, Diet/Supplement, and Multi-modal. When considering all trial types collectively, the findings suggest that lifestyle clinical trials are generally safe. There was no significant increase in the relative risk of experiencing an SAE in the intervention group compared to the control group. However, in terms of relative risk of death, an increase of 28% was observed in the intervention compared to the control, which was statistically significant (X2 (1, N = 36), p < 0.00688). Nevertheless, this increase did not surpass age-adjusted U.S. mortality rates. Assessing the data by intervention type, Diet/Supplement, and Multi-modal trials displayed an elevated relative risk of SAEs in the intervention. Diet/Supplement trials had a 16% increase (X2 (1, N = 2), p < 0.0263), and Multi-modal trials had a 365% increase (X2 (1, N = 5), p < 0.000213). Diet/Supplement trials also showed a 67% increased risk of death (X2 (1, N = 2), p < 0.000197).

Conclusions

These findings should be cautiously considered due to the low rate of reporting, but underscore the significance of reporting clinical trial results, enhancing transparency, and facilitating more accurate safety assessments in cognitive aging and lifestyle interventions for older adults.

The Bio-Hermes Study: Biomarker database developed to investigate blood-based and digital biomarkers in community-based, diverse populations clinically screened for Alzheimer's disease

INTRODUCTION

Alzheimer's disease (AD) trial participants are often screened for eligibility by brain amyloid positron emission tomography/cerebrospinal fluid (PET/CSF), which is inefficient as many are not amyloid positive. Use of blood-based biomarkers may reduce screen failures.

METHODS

We recruited 755 non-Hispanic White, 115 Hispanic, 112 non-Hispanic Black, and 19 other minority participants across groups of cognitively normal (n = 417), mild cognitive impairment (n = 312), or mild AD (n = 272) participants. Plasma amyloid beta (Aβ)40, Aβ42, Aβ42/Aβ40, total tau, phosphorylated tau (p-tau)181, and p-tau217 were measured; amyloid PET/CSF (n = 956) determined amyloid positivity. Clinical, blood biomarker, and ethnicity/race differences associated with amyloid status were evaluated.

RESULTS

Greater impairment, older age, and carrying an apolipoprotein E (apoE) ε4 allele were associated with greater amyloid burden. Areas under the receiver operating characteristic curve for amyloid status of plasma Aβ42/Aβ40, p-tau181, and p-tau217 with amyloid positivity were ≥ 0.7117 for all ethnoracial groups (p-tau217, ≥0.8128). Age and apoE ε4 adjustments and imputation of biomarker values outside limit of quantitation provided small improvement in predictive power.

DISCUSSION

Blood-based biomarkers are highly associated with amyloid PET/CSF results in diverse populations enrolled at clinical trial sites.

HIGHLIGHTS

Amyloid beta (Aβ)42/Aβ40, phosphorylated tau (p-tau)181, and p-tau 217 blood-based biomarkers predicted brain amyloid positivity. P-tau 217 was the strongest predictor of brain amyloid positivity. Biomarkers from diverse ethnic, racial, and clinical cohorts predicted brain amyloid positivity. Community-based populations have similar Alzheimer's disease (AD) biomarker levels as other populations. A prescreen process with blood-based assays may reduce the number of AD trial screen failures.

Using Focus Groups to Explore Older Black Men's Perception of Dietary Interventions

Older Black men are underrepresented in research despite being disproportionately affected by Alzheimer's disease (AD) and cardiovascular (CV) risk factors related to AD compared with non-Hispanic Whites. Although dietary interventions have shown promise to reduce modifiable CV risk factors related to AD, Black Americans have lower adherence likely due to lack of cultural considerations. Using a noninterventional convergent parallel mixed-methods approach, this study examined the cultural contexts that inform perceptions of dietary interventions among older Midwestern Black men. All participants completed an online demographic and dietary habit survey prior to focus group discussions. Two focus group discussion sessions were conducted with a total of 10 cognitively normal Black men aged 55 years and older. Survey data were analyzed using a frequency analysis and qualitative data were analyzed using a six-step thematic analysis process. Most men indicated having hypertension (N = 7, 77.8%) and currently not following a dietary eating pattern (N = 8, 88.9%). Emerging themes identified included (1) knowledge of dementia, (2) perceptions of dietary interventions, (3) barriers impacting participation in dietary interventions, and (4) overcoming barriers to engage Black men in dietary interventions. Findings from this study should inform the design of future dietary interventions for AD prevention to enhance participation among older Black men.

A Retrospective Analysis of Serious Adverse Events and Deaths in US-Based Lifestyle Clinical Trials for Cognitive Health

This retrospective analysis assessed the serious adverse events and deaths reported in lifestyle clinical trials designed to enhance cognitive health in older adults living in the United States. Data was collected from studies conducted between January 1, 2000, and July 19, 2023, using the ClinicalTrials.gov application programming interface. Our query revealed that 76% of these studies did not report trial results. The remaining studies with reported results were categorized under one of four intervention types: Cognitive/Behavioral, Exercise/Movement, Diet/Supplement, and Multi-modal. When all trial types are considered together, the results indicate that lifestyle clinical trials are safe, with no significant increase in relative risk of experiencing an SAE in an intervention group over a control group. And although the increase in relative risk of death in an intervention group over a control group was significant at 28% (X2 (1, N = 36), p < 0.00688), the probability of death was not higher than the U.S. mortality rates by age. When assessing the data using intervention type, Diet/Supplement trials and Multi-modal trials both had an increase in relative risk of experiencing an SAE in the intervention over the control group, with Diet/Supplement trials at 16% (X2 (1, N = 2), p < 0.0263) and Multi-modal trials at 365% (X2 (1, N = 5), p < 0.000213). The Diet/Supplement trials also had an increased risk of death at 67% (X2 (1, N = 2), p < 0.000197). These results should be taken with careful consideration. Due to such a low reporting rate, the 36 studies included in this analysis do not accurately represent the majority of lifestyle clinical trials conducted in the U.S. This study is valuable in that it highlights the importance of reporting clinical trial results, which will improve transparency in trial results and allow for more accurate assessments of safety in the growing field of cognitive aging and lifestyle interventions for older adults.

Development of a Culturally Adapted Dietary Intervention to Reduce Alzheimer's Disease Risk among Older Black Adults

The objective of this study is to identify and understand knowledge and attitudes that influence dietary practices among older Black adults using a community-engaged approach. This is a non-interventional mixed methods study designed to inform the development of an adapted brain-healthy soul food diet intervention. A purposive sampling approach was used to conduct seven semi-structured focus group discussions and an online quantitative survey. In total, 39 participants who self-identified as Black, aged 55 years and older, English speaking, and who were cognitively normal with an AD8 < 2; (25.6% men; 74.4% women) participated in the online survey and one of the seven 60 min virtual focus group discussions (5-7 per focus group). Quantitative frequency data from the online surveys were analyzed using descriptive statistics. Qualitative focus group data were analyzed using a 6-step thematic analysis process. Five themes emerged: dementia awareness; practices shaping food choices and consumption; barriers to eating healthy; instrumental support; and elements of a culturally adapted brain-healthy dietary intervention. Older Black adults perceived an adapted MIND dietary model as the most acceptable with the incorporation of salient cultural characteristics and strategies within both the design and delivery phases.

Impact of Diet and Exercise Interventions on Cognition and Brain Health in Older Adults: A Narrative Review

The ability to preserve cognitive function and protect brain structure from the effects of the aging process and neurodegenerative disease is the goal of non-pharmacologic, lifestyle interventions focused on brain health. This review examines, in turn, current diet and exercise intervention trends and the collective progress made toward understanding their impact on cognition and brain health. The diets covered in this review include the Mediterranean diet (MeDi), Dietary Approaches to Stop Hypertension (DASH), Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND), ketogenic diet, intermittent fasting, and weight loss management. The exercise approaches covered in this review include endurance, resistance, combined exercise programs, yoga, tai chi, and high-intensity interval training. Although valuable evidence is building concerning how diet and exercise influence cognitive performance and brain structure, many of the open questions in the field are concerned with why we see these effects. Therefore, more strategically designed intervention studies are needed to reveal the likely multiple mechanisms of action in humans.

Essential Amino Acids, Vitamins, and Minerals Moderate the Relationship between the Right Frontal Pole and Measures of Memory

SCOPE

Nutrition has increasingly been recognized for its ability to help prevent and protect against disease, inspiring new programs of research that translate findings from nutritional science into innovative assessment tools, technologies, and therapies to advance the practice of modern medicine. A central aim in this effort is to discover specific dietary patterns that promote healthy brain aging and moderate the engagement of neural systems known to facilitate cognitive performance in later life.

METHODS AND RESULTS

The present study therefore investigates estimates of nutrient intake derived from food frequency questionnaires, structural measures of brain volume via high-resolution magnetic resonance imaging, and standardized neuropsychological measures of memory performance in nondemented elders (n = 111) using a moderation analysis. The results reveal that the essential amino acids, vitamins, and minerals nutrient pattern moderates the positive relationship between the volume of the right frontal pole and measures of both delayed and auditory memory.

CONCLUSIONS

Our findings demonstrate that a nutrient pattern including macro- and micronutrients moderate the effect of brain structure on cognitive function in old age and support the efficacy of interdisciplinary methods in nutritional cognitive neuroscience for the study of healthy brain aging.