Asymptomatic carotid stenosis is associated with mobility and cognitive dysfunction and heightens falls in older adults

Abstract

Background: Atherosclerosis of the carotid bifurcation with plaque formation causes asymptomatic carotid artery stenosis (ACAS), which may also be associated with cerebral hypoperfusion. Cerebral hypoperfusion adversely affects multiple aspects of mobility and cognition. This study tests the hypothesis that community-dwelling older adults with a 50% or greater diameter-reducing ACAS will have mobility and cognitive impairments that heighten their risk for falls.

Methods: Eighty community-dwelling adults completed a mobility assessment (Short Physical Performance Battery, Berg Balance Scale, Four Square Step Test, Dynamic Gait Index, Timed Up and Go, and gait speed), self-reported physical function (Activities-Specific Balance Confidence, SF-12 Physical Function Component), and cognitive tests (Mini-Mental State Examination). Falls were recorded for the past 6 months. Standardized carotid ultrasound examination classified participants into no stenosis (<50% diameter reduction) (n = 54), moderate stenosis (50%-69%) (n = 17), and high-grade stenosis (70%-99%) (n = 9) groups. Linear and logistic regression analyses determined the associations between these measures and the degree of stenosis (three groups).

Results: Logistic regression analysis showed their degree of stenosis was associated with reductions in mobility (Short Physical Performance Battery [P = .008], Berg Balance Scale [P = .0008], Four Square Step Test [P = .005], DGI [P = .0001], TUG [P = .0004], gait speed [P = .02]), perceived physical function (ABC [P < .0001], SF-12 Physical Function Component [P < .0001]), and cognition (MMSE [P = .003]). Adults with moderate- and high-grade stenosis had a greater incidence of falls compared with those without stenosis (relative risk, 2.86; P = .01). Results remained unchanged after adjustment for age, sex and cardiovascular risk factors.

Conclusions: ACAS is associated with impaired mobility and cognition that are accompanied with increased fall risk. These impairments increased with worsening severity.

Keywords: Asymptomatic carotid artery stenosis; Balance; Cognition; Falls; Physical function.

Fig 1.

Boxplots of mobility function measures (gait and balance) for participants without carotid artery stenosis (black boxes), with moderate stenosis (50%−69% diameter reducing) (red boxes) and with high-grade stenosis (70%−99% diameter reducing) (blue boxes). Median, horizontal line in the box; top line of the box, upper quartile (75th percentile); bottom line of the box, lower quartile (25th percentile); Filled square, mean. The ends of the whiskers (vertical lines) indicate the minimum and maximum values. *Adjusted P values based on logistic regression. BBS, Berg Balance Scale; DGI, Dynamic Gait Index; FSST, Four Square Step Test; SPPB, Short Physical Performance Battery; TUG, Timed Up and Go.

Fig 2.

Boxplots of cognitive function, and self-reported balance confidence, physical activity, and physical function for participants without carotid artery stenosis (black boxes), with moderate stenosis (50%−69% diameter reducing) (red boxes) and with high-grade stenosis (70%−99% diameter reducing) (blue boxes). Median, central line in the box; top line, upper quartile (75th percentile), lower quartile (25th percentile), mean is central square. The ends of the whiskers (vertical lines) indicate the minimum and maximum values. *Adjusted P values based on logistic regression. ABC, Activities-Specific Balance Confidence Scale; MMSE, Mini-Mental State Examination; PASE, Physical Activity Scale for the Elderly; SF12, Medical Outcome Survey Short Form 12 Physical Function Component.