Gene-physical activity interactions in lower extremity performance: inflammatory genes CRP, TNF-α, and LTA in community-dwelling elders

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

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.

Association of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) with Muscle Strength in Community-Dwelling Elderly with Knee Osteoarthritis

Purpose: The purpose of this study was to evaluate the correlation between muscle strength and knee symptoms (pain, stiffness, and functional limitation) regardless of the presence of radiologic knee osteoarthritis (RKOA) in community-dwelling elderly. Patients and methods: This cross-sectional study used data from the Namgaram-2 cohort. The Namgaram-2 cohort consisted of participants living in three rural communities. Such participants were included for studies on activity limitation due to age-related musculoskeletal disorders including knee osteoarthritis, osteoporosis, and sarcopenia. The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), a health assessment tool for patients with arthritis in lower extremities, was used to assess health-related quality of life (HRQOL). Muscle strengths were measured by knee strength (by using the isokinetic dynamometer) and hand grip strength. Results: The WOMAC pain of Kallgren–Lawrence (K/L) grade < 2 was correlated with age, grip strength, nutrition status, and knee extension 180 peak torque. The WOMAC pain of K/L grade ≥ 2 was correlated with age, nutrition status, and knee extension 60 peak torque. The WOMAC stiffness of K/L grade < 2 was correlated with having a spouse, nutrition status, and knee extension 60 peak torque. The WOMAC stiffness of K/L grade ≥ 2 was correlated with knee extension 60 peak torque. The WOMAC function of K/L grade < 2 was correlated with age, grip strength, osteoporosis, nutrition status, and knee extension 180 peak torque. The WOMAC function of K/L grade ≥ 2 was correlated with age, nutrition status, and knee extension 60 peak torque. Conclusion: Muscle strength as measured by grip strength and knee extension was statistically significantly correlated with the WOMAC scores in patients with knee symptoms regardless of whether radiologic signs of knee osteoarthritis were observed.

Associations of TNF-α -308 G>A and TNF-β 252 A>G with Physical Function and BNP-Rugao Longevity and Ageing Study

OBJECTIVES

To explore the associations of TNF-α -308 G>A (rs1800629) and TNF-β 252 A>G (rs909253) with physical function and plasma B-type natriuretic peptide (BNP).

METHODS

Data of 1747 community-dwelling elders from the ageing arm of the Rugao Longevity and Ageing Study was used. Physical function was measured by handgrip strength, Timed Up and Go (TUG) test and 5-meter walking test (5MWT).

RESULTS

AA genotype of the TNF-α -308 G>A was associated with higher mean time of TUG test and 5MWT (multivariable adjusted β=5.75 and 5.70, respectively, p<0.05), compared with GG genotype. For the TNF-β 252 A>G polymorphism, GG genotype was associated with higher mean time of TUG test and 5MWT (multivariable adjusted β=1.55 and 0.83, respectively, p<0.05) and lower handgrip strength (multivariable adjusted β=-0.69, p<0.05), compared with AA genotype. Further, GG was associated with greater odds of low handgrip strength (OR=1.47, 95% CI=1.06-2.04), low speed of TUG test (OR=1.87, 95% CI=1.20-2.01) and elevated BNP (OR=1.30, 95% CI=1.08-1.84). GG also interacted with elevated BNP to be associated with greater odds of low handgrip strength and 5MWT.

CONCLUSIONS

TNF-β 252 A>G was associated with physical function measurements, plasma BNP level, and odds of elevated BNP in an elderly population. TNF-β 252 A>G also interacted with elevated BNP to be associated with greater odds of physical function measurements.