Risk factors accelerating cerebral degenerative changes, cognitive decline and dementia.

OBJECTIVES: Factors accelerating cerebral degenerative changes represent potentially modifiable risks for cognitive decline. Putative risk factors accelerating subtle cognitive decline and dementia were correlated with repeated measures of cerebral atrophy, CT densitometry, perfusions and cognitive testing among neurologically and cognitively normative ageing volunteers.
METHODS: Two hundred and twenty-four normative subjects at increased risk for cognitive decline were admitted to the study. Mean entry age was 59. 5+/-15.8 years. Mean follow-up is 4.3+/-3.1 years. At follow-up, 22 developed subtle cognitive decline (deltaCCSE>/=-3), 19 became demented, eight with vascular type (VAD) and 11 with Alzheimer's type (DAT) and 183 remain cognitively unchanged. Standardized questionnaires, medical, neuropsychological, neurological and blood work examinations were obtained. Cerebral atrophy, tissue densities and perfusions were measured by xenon-enhanced CT.
RESULTS: After age 60, cerebral atrophy, ventricular enlargement, polio- and leuko-araiosis geometrically increased as perfusions declined. Risk factors accelerating perfusional decline, cerebral atrophy, polio-araiosis and leuko-araiosis (thinning of grey-white matter densities) were: transient ischaemic attacks (TIAs), hypertension, smoking, hyperlipidemia, male gender. At age 71.5+/-11.9, subtle cognitive decline began, accelerated by TIAs, hypertension and heart disease. Leuko-araiosis began before cognitive decline. TIAs, hypertension and hyperlipidemia correlated with VAD. Excessive cortical perfusional decreases and cerebral atrophy correlated with cognitive decline. Family history of neurodegenerative disease correlated with DAT.
CONCLUSION: TIAs, hypertension, hyperlipidemia, smoking and male gender accelerate cerebral degenerative changes, cognitive decline and dementia. Copyright 1999 John Wiley & Sons, Ltd.