in values after age 65 years. The average posterior probability of allocating each
participant to the three groups was 0.85–0.88 for serum albumin level and 0.88–0.92
for serum hemoglobin level, indicating a good fit of the model of group trajectories
to individual trajectories. When compared to participants in the high trajectory
group, those in the moderate and low trajectory groups of serum albumin level had
HRs of 1.22 (95% CI, 0.92–1.61) and 1.76 (1.21–2.57), respectively, for incident
disabling dementia. Participants in the moderate and low trajectory groups for
hemoglobin levels had HRs of 1.27 (0.91–1.77) and 1.69 (1.13–2.51), respectively,
for incident disabling dementia as compared with those in the high trajectory group.
In this first study to show age trajectories in nutritional biomarkers in a
community-based study, three distinct trajectory patterns (high, moderate, and
low) for serum albumin and hemoglobin levels were identified among communitydwelling Japanese aged 65–90 years. About 90% of older Japanese (the high and
moderate trajectory groups) maintained a serum albumin level higher than 4.0 g/dL
in later life. Although 11% of older adults (the low trajectory group) did not reach the
cutoff for hypoalbuminemia (Gatta, Verardo, & Bolognesi, 2012), they had a high
risk of subsequent LTCI certification and death (Higashiguchi et al., 2008) after age
65 years. With respect to hemoglobin level, about 25% of older Japanese (the high
trajectory group) maintained a level higher than 14.3 g/dL in later life, and about half
(the moderate trajectory group) had a level higher than 13.0 g/dL until they reached
age 87 years. Overall, 21% of older adults (the low trajectory group) had levels
consistent with unexplained anemia (10.5–12 g/dL) (Makipour, Kanapuru, &
Ershler, 2008) after age 80 years. These findings highlight the importance of
interventions that improve nutritional status and management of associated diseases
in older adults with low serum albumin and hemoglobin levels. Moreover, it is
important to acquire healthy dietary lifestyle from younger age for future dementia
prevention.
5 Trajectories of Aging (Taniguchi et al., 2017b)
and Trajectories Over Time in Cognitive Function
The MMSE (Folstein, Folstein, & McHugh, 1975) is the most widely used short
psychometric test for measuring global cognitive function in epidemiological and
clinical studies. No study had used repeated-measures analysis to investigate trajectories of aging in relation to cognitive function. This prospective study of
nondemented community-dwelling older adults used repeated measures data from
the Kusatsu Longitudinal Study to identify potential MMSE score trajectories of
aging among community-dwelling older Japanese and determine whether these
MMSE score trajectories were associated with incident disabling dementia, after
adjustment for important confounders.
To be eligible for the study, individuals had to be free of dementia at baseline. The
data source for the present study was 1724 adults from the Kusatsu Longitudinal
68
Y. Taniguchi and H. Matsushita
participant to the three groups was 0.85–0.88 for serum albumin level and 0.88–0.92
for serum hemoglobin level, indicating a good fit of the model of group trajectories
to individual trajectories. When compared to participants in the high trajectory
group, those in the moderate and low trajectory groups of serum albumin level had
HRs of 1.22 (95% CI, 0.92–1.61) and 1.76 (1.21–2.57), respectively, for incident
disabling dementia. Participants in the moderate and low trajectory groups for
hemoglobin levels had HRs of 1.27 (0.91–1.77) and 1.69 (1.13–2.51), respectively,
for incident disabling dementia as compared with those in the high trajectory group.
In this first study to show age trajectories in nutritional biomarkers in a
community-based study, three distinct trajectory patterns (high, moderate, and
low) for serum albumin and hemoglobin levels were identified among communitydwelling Japanese aged 65–90 years. About 90% of older Japanese (the high and
moderate trajectory groups) maintained a serum albumin level higher than 4.0 g/dL
in later life. Although 11% of older adults (the low trajectory group) did not reach the
cutoff for hypoalbuminemia (Gatta, Verardo, & Bolognesi, 2012), they had a high
risk of subsequent LTCI certification and death (Higashiguchi et al., 2008) after age
65 years. With respect to hemoglobin level, about 25% of older Japanese (the high
trajectory group) maintained a level higher than 14.3 g/dL in later life, and about half
(the moderate trajectory group) had a level higher than 13.0 g/dL until they reached
age 87 years. Overall, 21% of older adults (the low trajectory group) had levels
consistent with unexplained anemia (10.5–12 g/dL) (Makipour, Kanapuru, &
Ershler, 2008) after age 80 years. These findings highlight the importance of
interventions that improve nutritional status and management of associated diseases
in older adults with low serum albumin and hemoglobin levels. Moreover, it is
important to acquire healthy dietary lifestyle from younger age for future dementia
prevention.
5 Trajectories of Aging (Taniguchi et al., 2017b)
and Trajectories Over Time in Cognitive Function
The MMSE (Folstein, Folstein, & McHugh, 1975) is the most widely used short
psychometric test for measuring global cognitive function in epidemiological and
clinical studies. No study had used repeated-measures analysis to investigate trajectories of aging in relation to cognitive function. This prospective study of
nondemented community-dwelling older adults used repeated measures data from
the Kusatsu Longitudinal Study to identify potential MMSE score trajectories of
aging among community-dwelling older Japanese and determine whether these
MMSE score trajectories were associated with incident disabling dementia, after
adjustment for important confounders.
To be eligible for the study, individuals had to be free of dementia at baseline. The
data source for the present study was 1724 adults from the Kusatsu Longitudinal
68
Y. Taniguchi and H. Matsushita