Supplementary Material for: Sex Differences in the Impact of <b><i>BDNF</i></b> Genotype on the Longitudinal Relationship between Physical Activity and Cognitive Performance

2018-02-02T08:56:13Z (GMT) by Watts A. Andrews S.J. Anstey K.J.
<b><i>Background:</i></b> Physical activity may preserve cognitive function in older adults, but benefits vary by sex and genetic factors. <b><i>Objective:</i></b> We tested the longitudinal association between physical activity and cognitive performance to de termine whether a common genetic polymorphism for brain-derived neurotrophic factor <i>(BDNF</i> Val66Met<i>)</i> moderated this effect. <b><i>Methods:</i></b> In a 12-year longitudinal population-based sample of older adults (<i>n</i> = 2,218), we used growth curve modeling to investigate whether the benefits of physical activity on cognitive preservation differed by <i>BDNF</i> genotype and sex across multiple cognitive domains including processing speed, attention, working memory, and episodic verbal memory. <b><i>Results:</i></b> The relationship between physical activity and cognitive performance was dependent on <i>BDNF</i> carrier status in males (Δχ<sup>2</sup> [Δdf] = 12.94 [4], <i>p</i> = 0.01), but not in females (Δχ<sup>2</sup> [Δdf] = 4.38 [4], <i>p</i> = 0.36). Cognition benefited from physical activity in male <i>BDNF</i> <i>met</i> noncarriers, but not <i>met</i> carriers, whereas cognition was not statistically significantly related to physical activity in females regardless of genotype. <b><i>Conclusion:</i></b> We observed longitudinal, but not cross-sectional, effects of physical activity on cognitive performance. Our study highlights the importance of longitudinal follow-up and consideration of sex differences in the relationships between physical activity, <i>BDNF</i> genotype, and cognitive decline. The findings contribute to understanding gene-lifestyle interactions in promoting cognitive health.