JAMA Netw Open: An unfortunate childhood may not be cured in a lifetime! Adverse childhood experiences are associated with a faster rate of cognitive decline in later life...

With the rapid increase in Chinese population ageing and the increase in life expectancy, age-related morbidity has become a major public health problem
.
According to a national survey conducted in China between 2015 and 2018, about 15.
5% of the population aged 60 or over had mild cognitive impairment, 6.
0% had dementia, and 3.
9% had Alzheimer's disease
.
Therefore, identifying modifiable risk factors associated with cognitive decline is essential
for planning public health interventions and promoting healthy ageing in China.
Current evidence suggests limited social connection or social isolation as risk factors for cognitive impairment and is increasingly common
in older adults.

However, there is limited
knowledge about the role of social isolation in the association between childhood threats and deprivation-related adverse childhood experiences (ACEs) and cognitive decline later in life.

Therefore, the main objective of this cohort study is to use data from the China Longitudinal Study on Health and Retirement (CHARLS) to explore the association
between threat-related and deprivation-related ACEs and cognitive decline in middle-aged and older adults in China.
The transformative role
of social isolation in the associations surveyed was also assessed.

Results showed that of the 6466 participants in the main analysis, 3301 (51.
1%) were male and 3165 (48.
9%) were female; The mean (SD) age at baseline was 57.
2 (8.
3) years
.
As shown in Table 1, 3300 participants (51.
0%) experienced one or more threat-related ACEs and 1349 participants (20.
9%) were exposed to at least 2 child threats
.
Individuals with two or more threat-associated ACEs were more likely to be male (813 [60.
3%] of 1349 versus 1448 [45.
7%] of 3166 compared with no exposure), while differences in other baseline features were not significant
between these groups.
Changes in overall cognition, episodic memory, and executive function over 4 years were also comparable across the 3 threat-related ACE categories (Figure A).

In terms of childhood deprivation, 3247 participants (50.
2%) were exposed to at least 1 of 5 deprivation-related ACEs, and 832 participants (12.
9%) experienced 2 or more (Table 1).

In addition, the decline in cognitive z-scores tended to be more pronounced during the 4-year follow-up period as the number of deprivation-related ACEs increased; The mean change in cognitive z-score from baseline to follow-up increased from 0.
13 (0 ACE) to 0.
28 (≥2 ACE); Trend P<.
001 ace>P<.
001 ace >Trend P=.
002) (Figure B).

Experiencing 1 deprivation-related ACE was associated with faster cognitive decline in global cognition (β = -0.
012 [95% CI, -0.
022 to -0.
002] SD/y) and executive function (β = -0.
010 [95% CI, -0.
020 to -0.
00002] SD/y) compared with no exposure, while individuals with at least 2 childhood deprivations experienced faster cognitive decline on all cognitive tests (β = −).
0.
035 [95% CI, −0.
050 to −0.
019] SD/y for global awareness; β of episodic memory = −0.
047 [95% CI, −0.
068 to −0.
025] SD/y; β=−0.
019 [95% CI, -0.
034 to −0.
004] SD/y for performing functions
).
However, this association
was not observed for the ACEs associated with the threat.

In addition, baseline social isolation was an important modifier for the association between deprivation-related ACE and overall cognitive decline (β=−0.
033 [95% CI, -0.
061 to -0.
005] SD/y; P = .
02) and execution function (β = −0.
032 [95% CI, −0.
059 to −0.
005] SD/y; P= .
02）
。

The results of this cohort study suggest that exposure to deprivation-related ACEs is independently associated
with a faster rate of annual cognitive decline in middle-aged and older adults in China.
In contrast, no threat-related ACEs were found to be associated
with cognitive decline later in life.
These findings further suggest that social isolation can alter the association of deprivation-associated ACEs with overall cognitive and executive function decline, and highlight the potential benefits
of promoting social integration in maintaining cognitive function later in life in individuals deprived of childhood.

Original source:

Lin L, Cao B, Chen W, Li J, Zhang Y, Guo VY.
Association of Adverse Childhood Experiences and Social Isolation With Later-Life Cognitive Function Among Adults in China.
JAMA Netw Open.
2022; 5(11):e2241714.
doi:10.
1001/jamanetworkopen.
2022.
41714