Prevalence of cognitive impairment in individuals aged over 65 in an urban area: DERIVA study

Abstract

BackgroundFew data are available on the prevalence of cognitive impairment (CI) in Spain, and the existing information shows important variations depending on the geographical setting and the methodology employed. The aim of this study was to determine the prevalence of CI in individuals aged over 65 in an urban area, and to analyze its associated risk factors.MethodsDesign: A descriptive, cross-sectional, home questionnaire-based study; Setting: Populational, urban setting. Participants: The reference population comprised over-65s living in the city of Salamanca (Spain) in 2009. Randomized sampling stratified according to health district was carried out, and a total of 480 people were selected. In all, 327 patients were interviewed (68.10%), with a mean age of 76.35 years (SD: 7.33). Women accounted for 64.5% of the total. Measurements: A home health questionnaire was used to obtain the following data: age, sex, educational level, family structure, morbidity and functionality. All participants completed a neuropsychological test battery. The prevalence data were compared with those of the European population, with direct adjustment for age and sex. Diagnoses were divided into three general categories: normal cognitive function, cognitive impairment - no dementia (CIND), and dementia.ResultsThe prevalence of CI among these over-65s was 19% (14.7% CIND and 4.3% dementia). The age-and sex-adjusted global prevalence of CI was 14.9%. CI increased with age (p < 0.001) and decreased with increasing educational level (p < 0.001). Significant risk factors were found with the multivariate analyses: age (OR = 1.08, 95%CI: 1.03-1.12), anxiety-depression (OR = 3.47, 95%CI: 1.61-7.51) and diabetes (OR = 2.07, 95%CI: 1.02-4.18). In turn, years of education was found to be a protective factor (OR = 0.79, 95%CI: 0.70-0.90). Although CI was more frequent among women and in people living without a partner, these characteristics were not significantly associated with CI risk.ConclusionsThe observed raw prevalence of CI was 19% (14.9% after adjusting for age and sex). Older age and the presence of diabetes and anxiety-depression increased the risk of CI, while higher educational level reduced the risk.

Serum folate, vitamin B12 and cognitive impairment in Chilean older adults

“…The superior schooling of Chilean women, as well as their prolonged interactions with family members, might stimulate cognitive function (28,29) . As in other studies, a lower risk of cognitive impairment was observed in those with higher levels of education (30)(31)(32) , which might be explained by greater cognitive reserves from superior cortical and neuronal synaptic capacities or improved compensation for deficiencies arising from other brain regions (33,34) . Although the difference in SF levels was statistically significant when comparing our participants with normal and impaired cognitive function (MMMSE plus PFAQ), it should be noted that in both cases SF levels were within the normal range, reaching supraphysiological levels (>20 μg/l) (35) in the group with normal cognitive function.…”

High Prevalence of Mild Cognitive Impairment in the Elderly: A Community-Based Study in Four Cities of the Hebei Province, China

“…Results from previous studies have also found that those with less education were more likely to be cognitively impaired [32,33]. Low education was thought to be related to cognitive impairment because individuals with lower education may reach old age with less initial cognitive reserve, poorer physical health, unhealthier lifestyles [34,35], and a greater risk for cognitive decline and generally appear to be on an earlier aging trajectory relative to those with higher levels of education.…”

Sex Differences in the Prevalence of and Risk Factors for Cognitive Impairment No Dementia among the Elderly in a Rural Area of Northern China: A Population-Based Cross-Sectional Study

“…Previous studies have reported a higher prevalence of CIND in rural populations, both in Western populations and in the Chinese population [15,[19][20][21]. Two studies from Spain reported that the prevalence of CIND was 23.3% in rural areas and 13.8 and 14.7% in urban areas [19,20].…”

“…Two studies from Spain reported that the prevalence of CIND was 23.3% in rural areas and 13.8 and 14.7% in urban areas [19,20]. The prevalence of CIND was 12.3% in rural populations from northern Portugal, with a rural/urban prevalence ratio of 1: 3 [21].…”