Healthy lifestyle and life expectancy with and without Alzheimer's dementia: population based cohort study.

OBJECTIVE To determine the impact of lifestyle factors on life expectancy lived with and without Alzheimer's dementia. DESIGN Prospective cohort study. SETTING The Chicago Health and Aging Project, a population based cohort study in the United States. PARTICIPANTS 2449 men and women aged 65 years and older. MAIN EXPOSURE A healthy lifestyle score was developed based on five modifiable lifestyle factors: a diet for brain health (Mediterranean-DASH Diet Intervention for Neurodegenerative Delay-MIND diet score in upper 40% of cohort distribution), late life cognitive activities (composite score in upper 40%), moderate or vigorous physical activity (≥150 min/week), no smoking, and light to moderate alcohol consumption (women 1-15 g/day; men 1-30 g/day). MAIN OUTCOME Life expectancy with and without Alzheimer's dementia in women and men. RESULTS Women aged 65 with four or five healthy factors had a life expectancy of 24.2 years (95% confidence interval 22.8 to 25.5) and lived 3.1 years longer than women aged 65 with zero or one healthy factor (life expectancy 21.1 years, 19.5 to 22.4). Of the total life expectancy at age 65, women with four or five healthy factors spent 10.8% (2.6 years, 2.0 to 3.3) of their remaining years with Alzheimer's dementia, whereas women with zero or one healthy factor spent 19.3% (4.1 years, 3.2 to 5.1) with the disease. Life expectancy for women aged 65 without Alzheimer's dementia and four or five healthy factors was 21.5 years (20.0 to 22.7), and for those with zero or one healthy factor it was 17.0 years (15.5 to 18.3). Men aged 65 with four or five healthy factors had a total life expectancy of 23.1 years (21.4 to 25.6), which is 5.7 years longer than men aged 65 with zero or one healthy factor (life expectancy 17.4 years, 15.8 to 20.1). Of the total life expectancy at age 65, men with four or five healthy factors spent 6.1% (1.4 years, 0.3 to 2.0) of their remaining years with Alzheimer's dementia, and those with zero or one healthy factor spent 12.0% (2.1 years, 0.2 to 3.0) with the disease. Life expectancy for men aged 65 without Alzheimer's dementia and four or five healthy factors was 21.7 years (19.7 to 24.9), and for those with zero or one healthy factor life expectancy was 15.3 years (13.4 to 19.1). CONCLUSION A healthy lifestyle was associated with a longer life expectancy among men and women, and they lived a larger proportion of their remaining years without Alzheimer's dementia. The life expectancy estimates might help health professionals, policy makers, and stakeholders to plan future healthcare services, costs, and needs

White matter hyperintensity, neurofilament light chain, and cognitive decline

Abstract Objective We aimed to determine whether combining white matter hyperintensity (WMH) with neurofilament light chain (NfL) could provide additional information for cognition in older adults. Methods Utilizing data from the population‐based Chicago Health and Aging Project, we studied 701 individuals with both biomarkers and cognitive data during the follow‐up period. NfL was measured using an ultrasensitive immunoassay, single‐molecule array technology. MRI scans of the brain were acquired using 1.5‐T systems. Global cognitive function was created as a composite measure of four neuropsychological tests, standardized and averaged to z‐scores. Multivariable linear mixed‐effects models were used to evaluate the association of WMH and NfL with the rate of cognitive decline. Results Higher WMH and NfL were associated with a faster rate of cognitive decline during the follow‐up; β‐coefficients (95%CIs) were −0.011 (−0.02, −0.001) and −0.010 (−0.017, −0.003), respectively. In individuals with lower concentration of NfL (i.e., bottom tertile), a higher WMH volume was associated with a faster cognitive decline (β: −0.030; 95%CI −0.046, −0.014). Similarly, in individuals with lower volumes of WMH (i.e., bottom tertile), a higher concentrations of NfL was associated with a faster cognitive decline (β: −0.023; 95%CI −0.042, −0.005). When we combined WMH with NfL, we noted a graded association with increasing volumes of WMH, particularly in people with lower NfL values. Interpretation While both biomarkers, WMH and NfL, were similarly associated with the annual rate of cognitive decline, our study suggests that they provide different underlying mechanisms affecting cognition

Serum neurofilament light chain, brain infarcts, and the risk of stroke: a prospective population-based cohort study

Neurofilament light chain (NfL), a neuron-specific protein, has been related to several neurodegenerative diseases. In addition, elevated levels of NfL have also been observed in patients admitted to the hospital for stroke, suggesting that NfL as a biomarker may extend well beyond neurodegenerative diseases. Therefore, using data from the Chicago Health and Aging Project (CHAP), a population-based cohort study, we prospectively investigated the association of serum NfL levels with incident stroke and brain infarcts. During a follow-up of 3603 person-years, 133 (16.3%) individuals developed incident stroke, including ischemic and hemorrhagic. The HR (95%CI) of incident stroke was 1.28 (95%CI 1.10-1.50) per 1 standard deviation (SD) increase of log10 NfL serum levels. Compared to participants in the first tertile of NfL (i.e., lower levels), the risk of stroke was 1.68 times higher (95%CI 1.07-2.65) in those in the second tertile and 2.35 times higher (95%CI 1.45-3.81) in those in the third tertile of NfL. NfL levels were also positively associated with brain infarcts; 1-SD in log10 NfL levels was associated with 1.32 (95%CI 1.06-1.66) higher odds of one or more brain infarcts. These results suggest that NfL may serve as a biomarker of stroke in older adults

Statin initiation and risk of incident Alzheimer disease and cognitive decline in genetically susceptible older adults

BACKGROUND AND OBJECTIVES: The association of statin initiation with incident Alzheimer disease (AD) dementia and cognitive decline by the APOE ε4 allele is unknown. Our objective was to examine whether the association of statin initiation with incident AD dementia and cognitive decline differs by the APOE ε4 allele. METHODS: This population-based longitudinal cohort study was conducted in 4 urban communities in Chicago, IL, United States, consisting of 4,807 participants. Statin initiation is based on the inspection of medications during home assessments. Clinical diagnosis for incident AD used the NINCDS-ADRDA criteria, and longitudinal measurements of global cognition consisted of episodic memory, perceptual speed, and the Mini-Mental State Examination tests. RESULTS: The study participants had a mean age of 72 years, consisting of 63% female individuals and 61% non-Hispanic Black individuals. During the study period, 1,470 (31%) participants reported statin initiation. In a covariate-adjusted competing risk model, statin initiation was associated with a reduced risk of incident clinical AD [hazard ratio (HR) 0.81 (95% CI 0.70-0.94)] compared with nonusers. This association was statistically significantly lower (p interaction = 0.015) among participants with the APOE ε4 allele [HR 0.60 (95% CI 0.49-0.74)] compared with those without the APOE ε4 allele [HR 0.96 (95% CI 0.82-1.12)]. The annual decline in global cognition (β = 0.021, 95% CI 0.007-0.034) and episodic memory (β = 0.020, 95% CI 0.007-0.033) was also substantially slower among participants with the APOE ε4 allele after statin initiation compared with nonusers. However, the association of statin initiation with cognitive decline was not significant among those without the APOE ε4 allele. DISCUSSION: Our findings suggest that statins might be associated with a lower risk of incident AD among individuals with the APOE ε4 allele. The benefits of statin therapy need further consideration in randomized clinical trials, especially among those with the APOE ε4 allele. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that among those aged 65 years or older, statin initiation was associated with a reduced risk of Alzheimer disease, especially in the presence of an APOE-e4 allele