Loneliness and the rate of motor decline in old age: the rush memory and aging project, a community-based cohort study
1 Department of Neurological Sciences, Rush Alzheimer's Disease Center, Rush University Medical Center, 600 S. Paulina, Chicago, Illinois. 60612, USA
2 Department of Behavioral Science, Rush Alzheimer's Disease Center, Rush University Medical Center, 600 S. Paulina Street, Chicago, Illinois. 60612, USA
3 Departments of Psychiatry and Neurology, Center for Neurobiology and Behavior, University of Pennsylvania, 125 South 31st Street, Philadelphia, Pennsylvania 19104, USA
BMC Geriatrics 2010, 10:77 doi:10.1186/1471-2318-10-77Published: 22 October 2010
Being alone, as measured by less frequent social interactions, has been reported to be associated with a more rapid rate of motor decline in older persons. We tested the hypothesis that feeling alone is associated with the rate of motor decline in community-dwelling older persons.
At baseline, loneliness was assessed with a 5-item scale in 985 persons without dementia participating in the Rush Memory and Aging Project, a longitudinal community-based cohort study. Annual detailed assessment of 9 measures of muscle strength and 9 motor performances were summarized in a composite measure of global motor function.
Linear mixed-effects models which controlled for age, sex and education, showed that the level of loneliness at baseline was associated with the rate of motor decline (Estimate, -0.016; S.E. 0.006, p = 0.005). For each 1-point higher level of loneliness at baseline, motor decline was 40% more rapid; this effect was similar to the rate of motor decline observed in an average participant 4 years older at baseline. Furthermore, this amount of motor decline per year was associated with about a 50% increased risk of death. When terms for both feeling alone (loneliness) and being alone were considered together in a single model, both were relatively independent predictors of motor decline. The association between loneliness and motor decline persisted even after controlling for depressive symptoms, cognition, physical and cognitive activities, chronic conditions, as well as baseline disability or a history of stroke or Parkinson's disease.
Among community-dwelling older persons, both feeling alone and being alone are associated with more rapid motor decline, underscoring the importance of psychosocial factors and motor decline in old age.