G×E Interaction Influences Trajectories of Hand Grip Strength

Area of Science:

• Gerontology
• Genetics
• Epidemiology

Background:

• Age-related decline in grip strength is a significant predictor of adverse health outcomes, including disability, frailty, and cognitive changes.
• While grip strength heritability is established, the genetic influence on its longitudinal change and the role of gene-environment interplay remain underexplored.

Purpose of the Study:

• To investigate the contribution of gene-environment interactions to grip strength trajectories across the adult lifespan.
• To examine the influence of genetic factors and their interplay with environmental factors on the rate of grip strength decline.

Main Methods:

• Longitudinal grip strength data from seven twin aging studies (N=10,681, aged 34-99) were analyzed using growth curve modeling.
• Fisher's test was applied to within-monozygotic twin-pair differences in growth curve parameters to assess genetic and environmental influences.
• Variability of within-pair differences was compared across APOE haplotypes to explore potential genetic moderation.

Main Results:

• Significant gene-environment interactions were identified, influencing the trajectories of grip strength over time.
• APOE ɛ2ɛ2/ɛ2ɛ3 haplotypes showed a potential, though not statistically significant, buffering effect against environmental influences on grip strength trajectories.

Conclusions:

• Gene-environment interactions play a crucial role in shaping age-related grip strength changes.
• Understanding these interactions is vital for developing targeted interventions to mitigate grip strength decline and associated health risks in aging populations.