Midlife risk factors for subtypes of dementia: a nested case-control study in Taiwan.
OBJECTIVE
To identify the midlife risk factors for subtypes of dementia newly developed later in life.


METHODS
A nested case-control study was conducted on 157 demented cases and 628 comparison cases selected from 40,636 men and women who were enrolled from 1982 to 1992. Four comparison cases were frequency-matched on age, time at enrollment (within 6 months), gender, and residential township. Midlife risk factors included vascular risk factors (body mass index [BMI], total cholesterol, total triglycerides, blood glucose, cerebrovascular accident [CVA] history, diabetes mellitus history, and hypertension history), cigarette smoking, and alcohol consumption. Dementia assessments were ascertained through the computerized data linkage from National Health Insurance Database from 2000 to 2002 and clinically confirmed by neurologists or psychiatrists. Conditional logistic regression analysis was used to estimate the matched odds ratio (OR) and its 95% confidence intervals (CI) for each risk factor.


RESULTS
A J-shaped relationship was observed between BMI (kg/m(2)) and dementia. The multivariate-adjusted ORs (95% CI) of developing dementia were 1.84 (1.02-3.33), 1.87 (1.08-3.23) and 2.44 (1.39-4.28), respectively, for BMIs of <20.5, 23.0-25.4, >or=25.5 compared with a BMI of 20.5-22.9 as the referent group (OR = 1.0). Similar findings were observed for Alzheimer disease (AD) and vascular dementia (VaD). The association between obesity (BMI >or=25.5) and both AD and VaD was statistically significant among cigarette smokers but not among nonsmokers. Additionally, history of CVA was a significant risk factor for VaD, but not for AD.


CONCLUSIONS
Being underweight, being overweight, and a cerebrovascular accident in midlife may increase the risk of dementia in late life.
Chiang
Chun-Ju
CJ
Graduate Institute of Epidemiology, College of Public Health, National Taiwan University, Taipei, Taiwan.
Yip
Ping-Keung
PK
Wu
Shiao-Chi
SC
Lu
Chin-Song
CS
Liou
Chia-Wei
CW
Liu
Hsiu-Chih
HC
Liu
Ching-Kuan
CK
Chu
Ching-Hua
CH
Hwang
Chi-Shin
CS
Sung
Sheng-Feng
SF
Hsu
Yaw-Don
YD
Chen
Cheng-Chung
CC
Liu
Shen-Ing
SI
Yan
Sui-Hing
SH
Fong
Chin-Shih
CS
Chang
Shu-Feng
SF
You
San-Lin
SL
Chen
Chien-Jen
CJ
D000368:Aged; D000428:Alcohol Drinking / Q000009:adverse effects / Q000453:epidemiology; D000544:Alzheimer Disease / Q000453:epidemiology* / Q000209:etiology; D001786:Blood Glucose / Q000378:metabolism; D015992:Body Mass Index; D016022:Case-Control Studies; D002784:Cholesterol / Q000097:blood; D015331:Cohort Studies; D003625:Data Collection / Q000706:statistics & numerical data; D003704:Dementia / Q000453:epidemiology* / Q000209:etiology; D015140:Dementia, Vascular / Q000453:epidemiology* / Q000209:etiology; D003920:Diabetes Mellitus / Q000453:epidemiology; D005260:Female; D015577:Geriatric Assessment / Q000706:statistics & numerical data*; D006801:Humans; D006937:Hypercholesterolemia / Q000150:complications / Q000453:epidemiology; D006973:Hypertension / Q000150:complications / Q000453:epidemiology; D008297:Male; D008403:Mass Screening / Q000706:statistics & numerical data; D008875:Middle Aged; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects / Q000453:epidemiology; D013223:Statistics as Topic; D020521:Stroke / Q000150:complications / Q000453:epidemiology; D013624:Taiwan; D014280:Triglycerides / Q000097:blood
D001786:Blood Glucose; D014280:Triglycerides; D002784:Cholesterol