Changes in Frailty Predict Changes in Cognition in Older Men: The Honolulu-Asia Aging Study

Abstract

Objectives As cognitive decline mostly occurs in late life, where typically it co-exists with many other ailments, it is important to consider frailty in understanding cognitive change. Here, we examined the association of change in frailty status with cognitive trajectories in a well-studied cohort of older Japanese-American men. Methods Using the prospective Honolulu-Asia Aging Study (HAAS), 2817 men of Japanese descent were followed (aged 71–93 at baseline). Starting in 1991 with follow-up health assessments every two to three years, cognition was measured using the Cognitive Abilities Screening Instrument (CASI). For this study, health data was used to construct an accumulation of deficits frailty index (FI). Using six waves of data, multilevel growth curve analyses were constructed to examine simultaneous changes in cognition in relation to changes in the frailty index (FI), controlling for baseline frailty, age, education, and APOE-ε4 status. Results On average, CASI scores declined by 2.0 points per year (95% confidence interval 1.9–2.1). Across six waves, each 10% within-person increase in frailty from baseline was associated with a 5.0 point reduction in CASI scores (95% confidence interval 4.7–5.2). Baseline frailty and age were associated both with lower initial CASI scores and with greater decline across the five follow-up assessments (p < 0.01). Conclusions Cognition is adversely affected by impaired health status in old age. Using a multidimensional measure of frailty, both baseline status and within-person changes in frailty were predictive of cognitive trajectories.

Dynamics of Frailty and Cognition After Age 50: Why It Matters that Cognitive Decline is Mostly Seen in Old Age

“…Some attribute this discrepancy to neural reserve, which is potentially maintained through cognitive activity [75]. Another possibility supported by the current research is that frailty may deplete neural reserve, thus cognitive impairment tends to increase as individuals become frailer [6]. The fact that brain pathology commonly associated with dementia and AD has also been found to be associated with frailty provides further support for the role of frailty in neural reserve [76].…”

“…For example, baseline frailty measured in three ways (i.e., FI from a comprehensive geriatric assessment, clinical frailty score, and the frailty phenotype) was associated with changes in cognitive function over time regardless of which frailty measure was used [4]. Armstrong and colleagues found frailty was associated with declines in cognitive function over a 3-and 6-year period [22] and that within person changes in frailty were associated with changes in cognition even after taking into consideration baseline frailty [6]. Buchman and colleagues found frailty predicted rate of cognitive decline and incident AD and suggested that frailty occurs before dementia [49].…”

“…Thus, that frailty and cognitive impairment are associated with each other is not surprising. Most studies report frailty as an antecedent [4][5][6][7] of cognitive impairment and others as an outcome of cognitive impairment [8,9]. The mutual influences between frailty and impaired cognition have been discussed [10], including a proposed construct of "cognitive frailty" [11].…”

Association between cognitive impairment and criteria for frailty syndrome among older adults

“…Frailty criteria also seem to be associated with cognitive impairment. A longitudinal survey involving 2,817 Japanese men showed that individual frailty factors were associated with a 16 to 18% reduction in their global cognitive status 36 . In another study, slowness and physical exhaustion ( fatigue) were associated with a reduction in global cognition 37 .…”

Physical frailty and decline in general and specific cognitive abilities

“…One should be to test ‘lead-lag’ effects, that is, whether changes in cognition follow changes in frailty, or vice versa, or whether there is interplay between these. While it is worth noting that there was little evidence for shared declines in physical and cognitive functions in the Lothian cohorts,5 6 multilevel growth curve analysis using the Honolulu-Asia Aging Study suggests that within-person increases in frailty predicted cognitive decline 9. This does not rule out dynamic interplay however, since Gale et al also found that decline in cognitive function predicted Fried frailty in the Lothian Birth Cohort 1936 (ref.…”