The impact of different types of exercise training on peripheral blood BDNF concentrations in older adults: A meta-analysis.

Abstract

Objectives

Alzheimer’s disease is associated with atrophy of the brain volume. Brain-derived neurotrophic factor (BDNF), a neurotrophin highly expressed in the hippocampus, has a protective effect on neuronal survival and maintenance in adulthood. Therefore, it plays an important role in preservation of brain function and size. The goal of this meta-analysis was to analyse the impact of aerobic and/or strength exercise training on BDNF concentrations in older adults (≥60 years).

Methods

This meta-analysis was completed in accordance with the PRISMA protocol. Inclusion criteria were: (i) studies with subjects (men and women) ≥ 60 years (ii) participation in a single exercise bout or an exercise program with (iii) measurements of blood BDNF; (iv) a comparison between (a) an intervention group and a control group or (b) two intervention groups, or (c) pre and post measurements of an exercise intervention without a control group. Studies with specific interest in known comorbidities such as diabetes, chronic pulmonary/cardiovascular diseases, musculoskeletal injuries or brain diseases affecting the peripheral and/or central nervous system, except for dementia, were excluded.

Results

Blood BDNF concentrations increased significantly in the exercise versus control group, both after a single exercise bout (Z=2.21, P=0.03) as well as after an exercise intervention (Z=4.72, P<0.00001). However, the increase in BDNF was significant only after strength training (Z=2.94, P=0.003) and combined training (Z=3.03, P=0.002) but not after aerobic exercise training (Z=0.82, P=0.41).

Conclusions

To increase blood BDNF concentrations in older adults, strength training and combined aerobic/strength training are preferred.