Cognitive impairment without dementia in older people: prevalence, vascular risk factors, impact on disability. The Italian Longitudinal Study on Aging.

OBJECTIVES

To investigate prevalence of "cognitive impairment, no dementia" (CIND) in the Italian older population, evaluating the association with cardiovascular disease and the impact on activities of daily living (ADL). CIND may provide pathogenic clues to dementia and independently affect ADL.

DESIGN

Cross-sectional examination in the context of the Italian Longitudinal Study on Aging.

SETTING

Random population sample from eight Italian municipalities.

PARTICIPANTS

A total of 3,425 individuals aged 65-84 years, residing in the community or institutionalized.

MEASUREMENTS

Study participants were screened for cognitive impairment by using the Mini-Mental State Examination. Trained neurologists examined those scoring <24. CIND diagnosis relied on clinical and neuropsychological examination, informant interview, and assessment of functional activities. Age-related cognitive decline (ARCD) was diagnosed in CIND cases without neuropsychiatric disorders responsible for the cognitive impairment.

RESULTS

Prevalence was 10.7% for CIND and 7.5% for ARCD, increased with age, and was higher in women. Age (odds ratio [OR], 1.09; 95% confidence interval [CI], 1.06-1.12), stroke (OR, 2.05; 95% CI, 1.26-3.35) and heart failure (OR, 1.73; 95% CI, 1.11-2.68) were significantly and positively associated with CIND at multivariate analysis. Education (OR, 0.61; 95% CI, 0.56-0.65) and smoking (OR, 0.72; 95% CI, 0.54-0.98) showed a negative correlation. Age and myocardial infarction were positively associated with ARCD, whereas a negative correlation was found for education and smoking. The effect of smoking was no more significant either on CIND or ARCD considering current habits or "pack year" exposure. CIND showed an independent impact on ADL (OR, 1.88; 95% CI, 1.41-2.49).

CONCLUSIONS

CIND is very frequent in older people. The effect of demographic variables and vascular conditions offers opportunities for prevention. The association with functional impairment is useful to evaluate the burden of disability and healthcare demands.