Longitudinal Association Between Walkability and Physical Activity in Twins.

Area of Science:

• Environmental Health
• Urban Planning
• Public Health

Background:

• The built environment, specifically neighborhood walkability, is a modifiable factor influencing physical activity.
• Previous research focused on cross-sectional associations between walkability and physical activity.

Purpose of the Study:

• To investigate the longitudinal associations between changes in neighborhood walkability and changes in physical activity.
• To establish temporality in the relationship between walkability and physical activity using a twin design.

Main Methods:

• Longitudinal data from 7,439 twins (2,800 pairs) from 2009-2020.
• Phenotypic and quasi-causal models to assess the effect of walkability change on physical activity change.
• Controlling for genetic and shared environmental confounds using a twin design.

Main Results:

• A 1-unit increase in neighborhood walkability change was associated with a 2.7-minute increase in weekly neighborhood walking.
• This association remained significant after controlling for genetic, shared environmental, and demographic factors.
• No significant association was found between changes in walkability and moderate-to-vigorous physical activity.

Conclusions:

• Changes in neighborhood walkability have a quasi-causal relationship with changes in neighborhood walking.
• This study establishes temporality, supporting walkability interventions to promote walking.