糖尿病是得老年癡呆和其他類型癡呆的危險因子

一個曆時十五年的前瞻性臨床研究顯示：糖尿病是得老年癡呆和其他類型癡呆的危險因子

People with diabetes were more likely to develop Alzheimer’s disease and other types of dementia, such as vascular dementia, which occurs when there is damage to blood vessels that eventually deprive the brain of oxygen.

For the study, a total of 1,017 people who were age 60 and older were given a glucose (sugar) tolerance test after an overnight fast to determine if they had diabetes. Study participants were monitored for an average of 11 years and then tested for dementia. During the study, 232 people developed dementia.

The study found that people with diabetes were 1.74 times more likely to develop dementia from any cause and twice as likely to develop Alzheimer’s disease as people with normal blood sugar levels. Of the 150 people with diabetes, 41 developed dementia (of these, 20 cases with Alzheimer’s disease), compared to 115 (51) of the 559 people without diabetes who developed dementia. The results remained the same after the researchers accounted for factors such as high blood pressure, high cholesterol and smoking. The risk of dementia was also higher in people who did not have diabetes, but had impaired glucose tolerance, or were “pre-diabetes.”

In addition, the study found the risk of developing dementia significantly increased when blood sugar was still high two hours after a meal.

[文摘]

Neurology. 2011 Sep 20;77(12):1126-34.
Glucose tolerance status and risk of dementia in the community: The Hisayama Study.
Ohara T, Doi Y, Ninomiya T, Hirakawa Y, Hata J, Iwaki T, Kanba S, Kiyohara Y.
SourceDepartment of Environmental Medicine, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan [e-mail].

Abstract
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.