Longitudinal Body Weight Change, Visit-To-Visit Body Weight Fluctuation, and Cognitive Decline Among Older Adults

Association between BMI trajectories in late-middle age and subsequent dementia risk in older age: a 26-year population-based cohort study

BACKGROUND

The association between body mass index (BMI) and dementia risk differs depending on follow-up time and age at BMI measurement. The relationship between BMI trajectories in late-middle age (50-65 years old) and the risk of dementia in older age (> 65 years old) has not been revealed.

METHODS

In the present study, participants from the Health and Retirement Study were included. BMI trajectories were constructed by combining BMI trend and variation information. The association between BMI trajectories at the age of 50-65 years and dementia risk after the age of 65 years was investigated. Participants with European ancestry and information on polygenic scores for cognitive performance were pooled to examine whether genetic predisposition could modify the association.

RESULTS

A total of 10,847 participants were included in the main analyses. A declining BMI trend and high variation in late-middle age were associated with the highest subsequent dementia risk in older age compared with an ascending BMI trend and low variation (RR = 1.76, 95% CI = 1.45-2.13). Specifically, in stratified analyses on BMI trajectories and dementia risk based on each individual's mean BMI, the strongest association between a declining BMI trend with high variation and elevated dementia risk was observed in normal BMI group (RR = 2.66, 95% CI = 1.72-4.1). Similar associations were found when participants were stratified by their genetic performance for cognition function without interaction.

CONCLUSIONS

A declining BMI trend and high variation in late-middle age were associated with a higher risk of dementia. Early monitoring of these individuals is needed to prevent dementia in older individuals.

Longitudinal body weight dynamics in relation to cognitive decline over two decades: A prospective cohort study

OBJECTIVE

The aim of this study was to investigate the associations of body weight change (BWC) and body weight variability (BWV) with changes in cognitive function.

METHODS

In 10,340 Health and Retirement Study participants (mean age: 68.0 years), body weight was reported biennially from 1993/1994 to 2016, and cognitive function was measured biennially from 1998 to 2016. We calculated BWC and BWV as the slope and root-mean-square error by regressing body weight on time for each individual. BWC was categorized by quintiles (Q): stable weight (Q2 to Q4), weight loss (Q1), and weight gain (Q5). BWV was categorized by tertiles. We used linear mixed regression models to assess associations with cognitive change.

RESULTS

Compared with stable weight (median: 0 kg/y), weight loss (median: -1.3 kg/y) predicted faster cognitive decline as demonstrated by mean difference of -0.023 (95% CI: -0.027 to -0.019) in cognitive change z score per year, whereas weight gain (median: 1 kg/y) was related to slower cognitive decline (β = 0.006; 95% CI: 0.003 to 0.009). Larger BWV was also associated with faster cognitive decline (β comparing the top with bottom tertile = -0.003; 95% CI: -0.006 to -0.0002). Similar associations were observed for episodic and working memory.

CONCLUSIONS

Weight loss and large BWV over a long time independently predicted faster cognitive decline in middle-aged and older adults, underscoring the importance of long-term dynamic body weight monitoring.

Association of Long-Term Body Weight Variability With Dementia: A Prospective Study

BACKGROUND

Body weight variability (BWV) refers to intraindividual weight loss and gain over a period. The association of long-term BWV with dementia remains unclear and whether this association is beyond body weight change is undetermined.

METHODS

In the Health and Retirement Study, a total of 5 547 dementia-free participants (56.7% women; mean [SD] age, 71.1 [3.2] years) at baseline (2008) were followed up to 8 years (mean = 6.8 years) to detect incident dementia. Body weight was self-reported biennially from 1992 to 2008. BWV was measured as the coefficient of variation utilizing the body weight reported 9 times across 16 years before baseline. Cox-proportional hazard model was used to estimate the hazard ratio (HR) and 95% confidence interval (CI).

RESULTS

Among the 5 547 participants, a total of 427 incident dementia cases were identified during follow-up. Greater long-term BWV was significantly associated with a higher risk of dementia (HR comparing extreme quartiles: 2.01, 95% CI: 1.48-2.72; HR of each SD increment: 1.21, 95% CI: 1.10-1.32; p-trend < .001) independent of mean body weight and body weight change. This significant association was even observed for BWV estimated approximately 15 years preceding dementia diagnosis (HR of each SD increment: 1.13, 95% CI: 1.03-1.23) and was more pronounced for that closer to diagnosis.

CONCLUSION

Our prospective study suggested that greater BWV may be a novel risk factor for dementia.

Association of cognition with leptin and vascular endothelial growth factor in individuals with type 2 diabetes mellitus

OBJECTIVE

The 10-year intensive lifestyle intervention (ILI) of the Look AHEAD study left a legacy of relative deficits in cognitive function among participants who entered the clinical trial with obesity or a history of cardiovascular disease. We hypothesized that altered levels of two weight-sensitive proangiogenic cytokines, leptin and vascular endothelial growth factor (VEGF), accounted for this concerning finding.

METHODS

Serum leptin and VEGF concentrations were determined in 1,279 Look AHEAD participants at baseline, proximal to cessation of the interventions (Epoch 1), and an average of 4 years later (Epoch 2). Up to four standardized assessments of attention, executive function, and memory were collected during follow-up. Mixed effects models were used to assess relative differences in leptin and VEGF concentrations between intervention groups and whether these accounted for changes in cognitive composite scores.

RESULTS

ILI and diabetes support and education differences in VEGF, but not leptin, concentrations varied depending on baseline history of cardiovascular disease and obesity, but neither leptin nor VEGF concentrations accounted for the relative decrements in cognitive function in participants assigned to ILI.

CONCLUSIONS

Alterations in two weight-sensitive proangiogenic cytokines did not account for the long-term adverse effects of ILI on cognitive function among adults with diabetes and either obesity or cardiovascular disease.

Association Between Late-Life Weight Change and Dementia: A Population-based Cohort Study

BACKGROUND

The impact of late-life weight changes on incident dementia is unclear. We aimed to investigate the associations of body mass index (BMI) and weight changes with dementia and to explore the role of APOE ɛ4 in these associations.

METHODS

A total of 1 673 dementia-free participants aged ≥60 and older were followed for an initial 6 years to detect changes in BMI/weight and then for an additional 6 years to detect incident dementia. BMI change ([BMIfirst 6-year follow-up - BMIbaseline]/BMIbaseline) was categorized as stable (≤5%), and moderate (5%-10%) or large (>10%) gain or loss. Weight change (weightfirst 6-year follow-up - weightbaseline) was categorized as stable (≤2.5 kg), and moderate (2.5-7.5 kg) or large (>7.5 kg) gain or loss. Dementia was diagnosed following standard criteria. Data were analyzed using Cox regression models.

RESULTS

Over the second 6-year follow-up period, 102 incident dementia cases were identified. Compared with stable BMI, the hazard ratios (95% CI) of dementia were 2.61 (1.09-5.54) and 2.93 (1.72-4.91) for BMI gain or loss >10%, respectively. The risk of dementia was higher among APOE ɛ4 carriers experiencing a large BMI gain (9.93 [3.49-24.6]) or loss (6.66 [2.83-14.4]) than APOE ɛ4 noncarriers with stable BMI. Similar results were observed for weight change and dementia associations.

CONCLUSIONS

BMI and weight changes showed U-shaped associations with dementia risk. Large bodyweight gain and loss alike are associated with an almost 3-fold higher risk of dementia, which may be amplified by APOE ɛ4.