Association of Low Muscle Mass With Cognitive Function During a 3-Year Follow-up Among Adults Aged 65 to 86 Years in the Canadian Longitudinal Study on Aging

Abstract

IMPORTANCE Cross-sectional studies have shown that combined low muscle mass and strength are associated with cognitive impairment. Whether low muscle mass, reflective of physiologic reserve, is independently associated with faster cognitive decline remains unknown. OBJECTIVE To investigate the associations between low muscle mass and cognitive decline in 3 distinct domains among adults aged at least 65 years. DESIGN, SETTING, AND PARTICIPANTS The Canadian Longitudinal Study on Aging is a prospective population-based cohort study of community-dwelling adults. Enrollment occurred from 2011 to 2015 with a 3-year follow-up. Analyses for this study were conducted on those aged at least 65 years from April 24 to August 12, 2020. EXPOSURE Appendicular lean soft tissue mass (ALM) was assessed by dual energy x-ray absorptiometry. Low ALM was identified using the sex-specific Canadian cut points. MAIN OUTCOMES AND MEASURES Memory was assessed using the Rey auditory verbal learning test. Executive function was assessed using the mental alternation test, Stroop high interference (words/dot) test, the animal fluency test, and the controlled oral word association test. Psychomotor speed was assessed using computer-administered choice reaction time. Composite scores by domain were created. RESULTSOf 8279 participants, 4003 (48%) were female, 8005 (97%) were White, and the mean (SD) age was 72.9 (5.6) years. A total of 1605 participants (19.4%) had low ALM at baseline.Participants with low ALM were older, had lower body mass index and physical activity level. The presence of low ALM at baseline was associated with faster 3-year cognitive decline in executive functions and psychomotor speed from multiple linear regressions. After adjusting for covariates including age, level of education, percentage body fat, and handgrip strength, low ALM remained independently associated with executive function decline (standardized β: −0.032; P = .03) only.Low ALM was not associated with memory. CONCLUSIONS AND RELEVANCE This cohort study found longitudinal associations between lowALM and cognition in aging. Identification of older adults with low muscle mass, a targetable modifiable factor, may help estimate those at risk for accelerated executive function decline. Further longer-term investigation of associations is warranted.

Strength and multiple types of physical activity predict cognitive function independent of low muscle mass in NHANES 1999–2002

“…It is, therefore, possible that any relationship between lower muscle mass and cognitive function may depend on the stimulus for muscle gain and resulting changes in neuromuscular function or strength. In support of this, a recent longitudinal cohort study similarly identified an inverse association between muscle mass and cognitive function; however, this association was attenuated once adjusted for grip strength 15 . Higher levels of leg strength have also been shown to correlate with better Mini‐Mental State Examination scores and executive functions, and whole‐body strength is positively associated with scores in cognitive test batteries 22 .…”

“…Using Canadian‐specific cutoffs (<7.30 kg/m 2 for males and < 5.42 kg/m 2 for females), Tessier et al. recently showed that low ALMI was associated with the rate of cognitive decline 15 . This resulted in around 20% of their cohort of adults aged 65−80 having low ALMI.…”

“…While some analyses have found an association between low skeletal muscle mass and declining cognition, 8,13–15 this association is not always present 16–19 . One possible explanation for this observed discrepancy is the mode through which skeletal muscle mass was accrued.…”

Exercise as therapy for neurodevelopmental and cognitive dysfunction in people with a Fontan circulation: A narrative review

“…Skeletal muscle secretes circulating myokines in response to exercise, that have a role in molecular and cellular neuroprotective processes in the brain, including the expression and regulation of BDNF, among others ( 87 – 89 ). Indeed, significant associations have been identified between sarcopenia and cognitive decline in healthy aging cohorts ( 90 – 92 ). Fontan-associated myopenia is a recently established phenomena ( 93 ) and may contribute to the myriad of risk factors associated with Fontan physiology and reduced cognitive functioning.…”

Increased GDF11 expression associated with increased survival of Grade 3 Gliomas

“…GDF11 seemed to be a crucial element of the young blood in both instances. In older adults, low muscle mass is associated with diminished cognitive function [4].…”