Prevalence of non-dementing cognitive disturbances and their association with vascular risk factors in an elderly population

Abstract

To assess the prevalence of "Cognitive Impairment No Dementia" (CIND) and circumscribed memory impairment (CMI) and to evaluate their association with vascular risk factors and stroke, we examined all people aged 65 years or over living in three rural Italian villages. The survey was conducted by means of a doorto-door 2-phase procedure. As phase 1 screening tests, we used the Mini-Mental State Examination (MMSE), or the Mental Status Questionnaire (MSQ) for people with < 3 years of schooling. In phase 2, four neurologists examined people with MMSE scores < 28 or MSQ scores < 10. The diagnostic study consisted of a clinical and neuropsychological examination which included a structured interview with a close respondent. Dementia was diagnosed by means of DSM III-R criteria. The study protocol was completed by 968 (84.4%) of the 1147 eligible people. Of the 968 participants, 690 (71.3 %) had no cognitive abnormalities, 78 (8.1%) were demented and 200 (20.6 %) suffered from CIND. The CIND group included 59 people (6.1% of the study population) with CMI. At the multiple logistic regression analysis, CIND was associated with age >or= 75 years (OR 1.6, 95 % CI 1.1.-2.2), < 5 years of schooling (OR 3.7, 95% CI 2.5.-5.5), stroke (OR 3.3, 95% CI 1.8.-6.1) and hypertension (OR 2.3, 95% CI 1.5.-3.5),while CMI was associated with < 5 years of schooling (OR 3.8, 95 % CI 1.9.-7.7), stroke (OR 3.1, 95% CI 1.2.-7.9) and hypertension (OR 3.7, 95% CI 1.7.-8.0). Using normotensive people as a reference group and adjusting for age, sex, education and stroke, the ORs for CIND were 1.9 (95 % CI 1.2.-3.0) for treated and 2.9 (95 % CI 1.8.-4.6) for untreated hypertensive patients. In conclusion, hypertension is significantly and independently associated with both CIND and CMI, and the risk of CIND is higher in untreated than treated hypertensive patients.