Glucose tolerance status and risk of dementia in the community: The Hisayama Study.
Ohara, T. MD; Doi, Y. MD, PhD; Ninomiya, T. MD, PhD; Hirakawa, Y. MD; Hata, J. MD, PhD; Iwaki, T. MD, PhD; Kanba, S. MD, PhD; Kiyohara, Y. MD, PhD
77(12):1126-1134, September 20, 2011.
(Format: HTML, PDF)
Objective: We investigated the association between glucose tolerance status defined by a 75-g oral glucose tolerance test (OGTT) and the development of dementia.
Methods: A total of 1,017 community-dwelling dementia-free subjects aged >=60 years who underwent the OGTT were followed up for 15 years. Outcome measure was clinically diagnosed dementia.
Results: The age- and sex-adjusted incidence of all-cause dementia, Alzheimer disease (AD), and vascular dementia (VaD) were significantly higher in subjects with diabetes than in those with normal glucose tolerance. These associations remained robust even after adjustment for confounding factors for all-cause dementia and AD, but not for VaD (all-cause dementia: adjusted hazard ratio [HR] = 1.74, 95% confidence interval [CI] = 1.19 to 2.53, p = 0.004; AD: adjusted HR = 2.05, 95% CI = 1.18 to 3.57, p = 0.01; VaD: adjusted HR = 1.82, 95% CI = 0.89 to 3.71, p = 0.09). Moreover, the risks of developing all-cause dementia, AD, and VaD significantly increased with elevated 2-hour postload glucose (PG) levels even after adjustment for covariates, but no such associations were observed for fasting plasma glucose (FPG) levels: compared with those with 2-hour PG levels of <6.7 mmol/L, the multivariable-adjusted HRs of all-cause dementia and AD significantly increased in subjects with 2-hour PG levels of 7.8 to 11.0 mmol/L or over, and the risk of VaD was significantly higher in subjects with levels of >=11.1 mmol/L.
Conclusions: Our findings suggest that diabetes is a significant risk factor for all-cause dementia, AD, and probably VaD. Moreover, 2-hour PG levels, but not FPG levels, are closely associated with increased risk of all-cause dementia, AD, and VaD.
GLOSSARY: AD: Alzheimer disease
CI: confidence interval
DSM-III-R: Diagnostic and Statistical Manual of Mental Disorders, 3rd edition, revised
FPG: fasting plasma glucose
HR: hazard ratio
IFG: impaired fasting glycemia
IGT: impaired glucose tolerance
NGT: normal glucose tolerance
OGTT: oral glucose tolerance test
PG: postload glucose
VaD: vascular dementia.
(C)2011 American Academy of Neurology