Glucose levels and risk of dementia.
BACKGROUND
Diabetes is a risk factor for dementia. It is unknown whether higher glucose levels increase the risk of dementia in people without diabetes.


METHODS
We used 35,264 clinical measurements of glucose levels and 10,208 measurements of glycated hemoglobin levels from 2067 participants without dementia to examine the relationship between glucose levels and the risk of dementia. Participants were from the Adult Changes in Thought study and included 839 men and 1228 women whose mean age at baseline was 76 years; 232 participants had diabetes, and 1835 did not. We fit Cox regression models, stratified according to diabetes status and adjusted for age, sex, study cohort, educational level, level of exercise, blood pressure, and status with respect to coronary and cerebrovascular diseases, atrial fibrillation, smoking, and treatment for hypertension.


RESULTS
During a median follow-up of 6.8 years, dementia developed in 524 participants (74 with diabetes and 450 without). Among participants without diabetes, higher average glucose levels within the preceding 5 years were related to an increased risk of dementia (P=0.01); with a glucose level of 115 mg per deciliter (6.4 mmol per liter) as compared with 100 mg per deciliter (5.5 mmol per liter), the adjusted hazard ratio for dementia was 1.18 (95% confidence interval [CI], 1.04 to 1.33). Among participants with diabetes, higher average glucose levels were also related to an increased risk of dementia (P=0.002); with a glucose level of 190 mg per deciliter (10.5 mmol per liter) as compared with 160 mg per deciliter (8.9 mmol per liter), the adjusted hazard ratio was 1.40 (95% CI, 1.12 to 1.76).


CONCLUSIONS
Our results suggest that higher glucose levels may be a risk factor for dementia, even among persons without diabetes. (Funded by the National Institutes of Health.)
Department of Medicine, University of Washington, Seattle, WA, USA. pcrane@uw.edu
Paul K
PK
Crane
Rod
R
Walker
Rebecca A
RA
Hubbard
Ge
G
Li
David M
DM
Nathan
Hui
H
Zheng
Sebastien
S
Haneuse
Suzanne
S
Craft
Thomas J
TJ
Montine
Steven E
SE
Kahn
Wayne
W
McCormick
Susan M
SM
McCurry
James D
JD
Bowen
Eric B
EB
Larson
D000368:Aged; D001057:Apolipoproteins E / Q000235:genetics; D001499:Bayes Theorem; D001786:Blood Glucose / Q000032:analysis*; D002318:Cardiovascular Diseases / Q000150:complications / Q000453:epidemiology; D003704:Dementia / Q000209:etiology*; D048909:Diabetes Complications / Q000209:etiology*; D003920:Diabetes Mellitus / Q000097:blood*; D004522:Educational Status; D005260:Female; D005500:Follow-Up Studies; D005838:Genotype; D006801:Humans; D006943:Hyperglycemia / Q000150:complications*; D008297:Male; D016016:Proportional Hazards Models; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects / Q000453:epidemiology
D001057:Apolipoproteins E; D001786:Blood Glucose