Public Health

Area of Science:

• Neuroscience
• Gerontology
• Cardiovascular Health

Background:

• Cerebral small vessel disease (CSVD) is characterized by demyelination, and physical activity is linked to higher myelin content in older adults.
• The mechanisms connecting physical activity and myelin health in CSVD are not well understood.
• High-density lipoprotein (HDL) plays a role in brain remyelination and is influenced by physical activity, suggesting a potential mediating role in the physical activity-myelin relationship.

Purpose of the Study:

• To investigate whether serum lipid levels, specifically HDL, LDL, and triglycerides, moderate the association between physical activity and myelin content in older individuals with CSVD and mild cognitive impairment.

Main Methods:

• Cross-sectional study involving 81 older adults with CSVD and mild cognitive impairment.
• Multiple regression models were used to assess the moderation effect of HDL, LDL, and triglycerides on the relationship between physical activity and myelin content.
• Analyses were adjusted for age, sex, education, BMI, total cholesterol, intracranial volume, and white matter lesions.

Main Results:

• Physical activity was positively associated with HDL levels and myelin content in several brain regions, including the anterior corona radiata, genu of the corpus callosum, and sagittal stratum.
• HDL was positively associated with myelin content in multiple brain areas, such as the body of the corpus callosum and posterior corona radiata.
• HDL levels significantly moderated the association between physical activity and myelin in the sagittal stratum, with higher physical activity linked to greater myelin in individuals with average or high HDL.

Conclusions:

• Physical activity may contribute to myelin health in individuals with CSVD, at least partly, through mechanisms involving HDL.
• Longitudinal studies are required to establish causality and confirm the role of HDL in mediating the effects of physical activity on myelin.