ASSOCIATION OF DIABETES-MELLITUS AND DEMENTIA - THE ROTTERDAM STUDY

Dementia and non-insulin-dependent diabetes mellitus (NIDDM) are highl y prevalent disorders in the elderly. Diabetes has repeatedly been rep orted to affect cognition, but its relation with dementia is uncertain . We therefore studied the association between diabetes and dementia i n the Rotterdam Study,, a large population-based study In the elderly, Of 6330 participants, aged 55 to 99 years old, complete information o n diabetes and presence of dementia was available, Diabetes was diagno sed as use of anti-diabetes medication or random or postload serum glu cose over 11 mmol/l. Dementia was diagnosed through a stepped approach , including a sensitive screening of all participants and a comprehens ive diagnostic work-up. Diabetes was present in 724 (11.4%) subjects. Of the 265 dementia patients 59 (22.3 %) had diabetes. Multiple logist ic regression analyses, adjusting for age and sex differences, reveale d a positive association between diabetes and dementia (odds ratio: 1. 3, 95 % confidence interval: 1.0-1.9), In particular, strong associati ons were found between dementia and diabetes treated with insulin (odd s ratio: 3.2, 95 % confidence interval: 1.4-7.5). The relation was str ongest with vascular dementia, but was also observed with Alzheimer's disease. These associations were independent of educational attainment , smoking, body mass index, atherosclerosis, blood pressure and antihy pertensive drug treatment, and could not be explained by clinical cere bral infarctions. The results suggest that NIDDM is associated with de mentia. Alzheimer's disease may be more frequent in elderly diabetic p atients treated with insulin.