The angiotensin-converting enzyme gene insertion/deletion polymorphism interacts with fear of falling in relation to stepping speed in community-dwelling older adults

ABSTRACT

Background

Despite the association of genetic factors with falls, balance, and lower extremity functioning, interaction of the angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism with fear of falling (FOF) in relation to stepping performance has, to the best of our knowledge, not been investigated in older adults.

Objective

The purpose of this study was to examine the interaction effects of the ACE I/D polymorphism with FOF in relation to stepping performance in older adults.

Methods

Eighty-eight community-dwelling adults 60 years or older participated in a cross-sectional observational study. Participants completed tests of rapid and distance stepping, and self-reported FOF (yes/no). Participants provided saliva for ACE genotyping. General linear models evaluated ACE genotype × FOF interaction effects in relation to stepping performance. The α level was set at 0.05.

Results

The ACE I/D polymorphism exhibited significant interaction effects (p for interactions 0.002 ≤ p ≤ .04) with FOF in relation to stepping speed. Relationships between FOF and stepping speed varied among ACE genotypes. The insertion/insertion (II) genotype was significantly associated (p = .01) with slow stepping in individuals with, but not without FOF (p > .05).

Conclusion

Variation in relationships between FOF and stepping speed among ACE genotypes suggests a role for the ACE I/D polymorphism in modifying relationships between FOF and stepping speed in older adults. The association of the ACE II genotype with slow stepping performance in individuals with, but not without FOF, suggests that older adults with the ACE II genotype and FOF may be at increased risk for poor stepping performance and associated functional declines.

KEYWORDS:

• ACE I/D polymorphism
• fear of falling
• stepping speed

Acknowledgments

The Physical Therapy Department at the University of Michigan-Flint provided funding for the study. We thank Kurt Shuler for conducting the genotyping for this study.

Disclosure statement

Allon Goldberg has received honoraria for speaking engagements on the topic of genomics for physical therapists. Other authors report no conflicts of interest.

Additional information

Funding

This work was supported by the Physical Therapy Department at the University of Michigan-Flint.