No association between the COMT Val158Met polymorphism and cognitive training response in healthy Shanghai community-dwelling elderly individuals.

Abstract

Cognitive training may have an effect on promoting the maintenance of cognitive functions in healthy elderly adults. The catechol-O-methyltransferase (COMT) variant Val158Met (rs4680) is a wellstudied functional variant that has been associated with differences in cognitive functions. Whether this COMT polymorphism is associated with cognitive performance after training remains unknown. We tested whether the COMT Val158Met polymorphism could influence the cognitive function over time in healthy community-dwelling elderly adults who participated in a multi-domain cognitive training intervention. A total of 147 healthy Chinese individuals at 70 years of age and older who met the inclusion criteria were recruited from one urban community in Shanghai. One group (n=88) accepted multi-domain cognitive training over the span of 12 weeks. The control group (n=59) did not receive any intervention. Individuals underwent a multi-domain neuropsychological test four times over the course of a year (baseline, post-intervention, and 6-12 months follow-up). Composite measures of cognitive function were identified from neuropsychological test scores via factor analysis. Effects of the intervention and carrying the COMT Val158Met allele on cognitive measures were evaluated via regression models. In cross-sectional analysis there were no baseline effects of rs4680 on cognitive function (P>0.05) with or without adjustment for demographic covariates. There was a very subtle effect of rs4680 on measures of processing speed at the post-intervention time point (beta = -0.28±0.13, P=0.03) and at the 6-month post-intervention time point (beta = -0.31±0.14, P=0.02), but not at 12-month post-intervention (P=0.15). The rs4680 genotype did not exhibit any significant effect on any other cognitive measures. Furthermore, there were no significant effects of rs4680 genotype over time on cognitive measures regardless of cognitive training intervention. COMT single nucleotide polymorphism rs4680 (Val158Met) does not appear to affect cognitive function over time in this cohort of individuals, nor does it interact to affect the intervention's effect on cognition over time. There are weak associations between rs4680 and processing speed but these must be interpreted with caution, as they do not appear to be consistent over time. The COMT Val158Met polymorphism does not appear to modify cognitive function following cognitive training in healthy elderly.