[Cognitive function among physically independent very old people in an urban community in Japan: the Itabashi...

This study was conducted to clarify the characteristics of cognitive function among physically independent very old people dwelling in an urban community in Japan. Five hundred and thirteen Old-Old (aged 75-84 years) and 168 Oldest-Old (aged 85-100 years) adults participated. We carried out the Mini-Mental State Examination (MMSE) for measuring cognitive functions in the elderly. Age-related differences in the total score and sub-scale scores of the MMSE were analyzed by sex using ANCOVA, controlling for education, vision and hearing problems. Mean MMSE scores for Old-Old and Oldest-Old males were 27.53 and 25.88, respectively, and those for Old-Old and Oldest-Old females were 27.77 and 24.98, respectively. Age-related differences in the MMSE total score between the Old-Old and Oldest-Old were observed in both sexes, suggesting that overall cognitive functions continue to decline over time in very old age. Age-related differences between the Old-Old and Oldest-Old in items measuring, registration, calculation and delayed recall were observed in both sexes, and in addition, time orientation, place orientation, delayed recognition, writing sentences, and copying figures were observed in females. These findings suggest that the faculties are those most sensitive to normal aging among very old individuals. There were no age group differences in five items: reverse spelling, naming objects, repeating a sentence, listening and obeying, and reading and obeying.