Ethnic variations in dementia: the contributions of cardiovascular, psychosocial and neuropsychological factors.
BACKGROUND
Ethnic variations in dementia rate have been reported worldwide. Understanding these differences is vital for aetiological research, clinical care and health service planning. While age and gender have been consistently implicated, the reasons behind interethnic variation remain unclear.


METHODS
We used data from the Singapore National Mental Health Survey (Elderly) in 2003, a cross-sectional population-based study to investigate the extent to which differences in cardiovascular risk factors, psychosocial factors and cognitive functional status contributed to ethnic differences in dementia prevalence among Chinese, Malays and Indians.


RESULTS
Ethnic differences in dementia prevalence (4.2% in Chinese, 9.4% in Malays and 8.8% in Indians) were not explained by differences in gender, age and education (Malays vs. Chinese: adjusted OR = 3.11; Indians vs. Chinese: OR = 4.30). Differences in cardiovascular factors, depression or leisure time activities contributed modestly to the differences, but the OR remained significantly elevated. Differences in Mini-Mental State Examination scores contributed the most to explaining the ethnic differences (Malays vs. Chinese: adjusted OR = 0.73; Indians vs. Chinese: OR = 1.18).


CONCLUSIONS
Cognitive functional reserve accounted for much of the ethnic differences in dementia prevalence and its assessment has implications for the detection and treatment of dementia in multiethnic populations.
Ng
Tze Pin
TP
Gerontological Research Programme, Faculty of Medicine, National University of Singapore, Singapore. pcmngtp@nus.edu.sg
Leong
Terence
T
Chiam
Peak Chiang
PC
Kua
Ee-Heok
EH
D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002318:Cardiovascular Diseases / Q000453:epidemiology* / Q000503:physiopathology / Q000523:psychology; D002681:China / Q000208:ethnology; D003071:Cognition / Q000502:physiology; D003430:Cross-Sectional Studies; D003704:Dementia / Q000453:epidemiology* / Q000503:physiopathology / Q000523:psychology; D003863:Depression / Q000453:epidemiology / Q000523:psychology; D005006:Ethnicity; D005260:Female; D006801:Humans; D007194:India / Q000208:ethnology; D007899:Leisure Activities; D008019:Life Style; D008296:Malaysia / Q000208:ethnology; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology; D009422:Nervous System Diseases / Q000150:complications / Q000453:epidemiology* / Q000523:psychology*; D009483:Neuropsychological Tests; D011569:Psychiatric Status Rating Scales; D012307:Risk Factors; D012737:Sex Factors; D012846:Singapore / Q000453:epidemiology; D012931:Social Environment; D012959:Socioeconomic Factors