Relationship Between Physical Activity and Brain Atrophy Progression

Atsumu Yuki; Sungchul Lee; Heungyoul Kim; Rumi Kozakai; Fujiko Ando; Hiroshi Shimokata

Disclosures

Med Sci Sports Exerc. 2012;44(12):2362-2368. 

In This Article

Abstract and Introduction

Abstract

Introduction: Brain atrophy is associated with impairment in cognitive function and learning function. The aim of this study was to determine whether daily physical activity prevents age-related brain atrophy progression.

Methods: The participants were 381 men and 393 women who had participated in both the baseline and the follow-up surveys (mean duration = 8.2 yr). Magnetic resonance imaging of the frontal and temporal lobes was performed at the time of the baseline and follow-up surveys. The daily physical activities and total energy expenditures of the participants were recorded at baseline with uniaxial accelerometry sensors. Multiple logistic regression models were fit to determine the association between activity energy expenditure, number of steps, and total energy expenditure variables and frontal and temporal lobe atrophy progression while controlling for possible confounders.

Results: In male participants, the odds ratio of frontal lobe atrophy progression for the fifth quintile compared with the first quintile in activity energy expenditure was 3.408 (95% confidence interval = 1.205–9.643) and for the number of steps was 3.651 (95% confidence interval = 1.304–10.219). Men and women with low total energy expenditure were at risk for frontal lobe atrophy progression. There were no significant differences between temporal lobe atrophy progression and physical activity or total energy expenditure.

Conclusion: The results indicate that physical activity and total energy expenditure are significant predictors of frontal lobe atrophy progression during an 8-yr period. Promoting participation in activities may be beneficial for attenuating age-related frontal lobe atrophy and for preventing dementia.

Introduction

Atrophy of brain structures is associated with impairment in cognitive function and learning function (the extreme case is Alzheimer disease).[21] Brain atrophy progresses with aging.[17] The gray matter volume decreases by approximately 15%, from the 20s through the 70s.[38] A previous study reported that a decline in cognitive function is associated with the progression rate of brain atrophy for 6 yr in normal elderly people.[33] Thus, preventing brain atrophy may be a promising strategy for preventing cognitive impairment and decline.

Physical exercise appears to induce neurogenesis in the brain not only in animals but also in humans.[11] The practice of juggling for 3 months increases the volume of gray matter in the bilateral midtemporal area and in the left posterior intraparietal sulcus in young people.[10] Similarly, the increase in brain volume in the anterior cingulate gyrus and frontal pole caused by juggling occurs in elderly people.[3] In particular, aerobic exercise appears to suppress global and regional brain atrophy to effectively increase brain volume.[14] Relatively little brain structural atrophy is seen in elderly people with high aerobic capacity.[7] Six months of aerobic exercise increases the volume of the frontal lobe, temporal lobe, and hippocampus.[8] Aerobic capacity is correlated with the preservation of gray matter in the medial–temporal, parietal, and frontal areas in elderly people.[18] Aerobic quick-step walking suppresses hippocampal atrophy and improves cognitive function in elderly people.[15] These reports suggest the possibility that aerobic exercise prevents brain atrophy.

We hypothesized that brain atrophy progression can be prevented in middle-age and elderly people with a high level of daily physical activity. Daily physical activities are correlated with aerobic capacity in middle-age and elderly people.[2,6] In cross-sectional studies, high physical activity levels are related to larger superior frontal volumes.[5] Increased physical activity is associated with greater average brain tissue volumes in the white matter of the corona radiata, extending into the parietal–occipital junction.[19] Although daily physical activities may prevent brain atrophy progression, there has been no specific longitudinal analysis showing that daily physical activity maintained at a high level prevents brain atrophy. Recent longitudinal studies have reported that elderly people with high levels of daily physical activity have a low risk of decline in cognitive function.[26,34] A demonstration of the prevention of brain atrophy progression by high levels of physical activity in a longitudinal study may support the association between daily physical activity and cognitive function.

The aim of this study was to determine whether high levels of daily physical activity prevent brain atrophy progression with aging. We assessed the progression of frontal and temporal lobe atrophy with aging using 8-yr follow-up surveys and magnetic resonance imaging (MRI) of middle-age and elderly people. We also recorded the amount of physical activity (activity energy expenditure and number of steps) and total energy expenditure using a uniaxial accelerometry sensor. We evaluated the association between brain atrophy progression and daily physical activity and total energy expenditure in 774 community-living, middle-age, and elderly Japanese people using longitudinal analysis.

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