Cohort Changes in Cognitive Function among Danish Centenarians

Background/Aim: The objective was to examine cohort changes in cognitive function in 2 cohorts of centenarians born 10 years apart. Methods: The Longitudinal Study of Danish Centenarians comprises all Danes reaching the age of 100 in the period April 1, 1995 through May 31, 1996. A total of 207 out of 276 persons participated (75%). The Danish 1905 Cohort Survey includes all individuals born in 1905. In total, 225 out of 364 persons who reached the age of 100 in the cohort participated in the most recent 2005 follow-up (62%). In both cohorts, cognitive function was assessed using the Mini-Mental State Examination. Results: There were no significant differences in cognitive score between the two centenarian birth cohorts. However, modest tendencies were seen towards better cognitive functioning for the centenarians in the 1905 cohort living at home compared to the home-dwelling ones in the 1895 cohort and worse cognitive performance for the centenarians in the 1905 group living in nursing homes compared to the nursing home dwellers in the 1895 cohort. Conclusion: The increasing number of centenarians may not entail larger proportions of cognitively impaired individuals in this extreme age group. Copyright © 2008 S. Karger AG, Basel Accepted: May 26, 2008 Published online: August 5, 2008 Henriette Engberg, MSc (Health) The Danish Aging Research Center Institute of Public Health, University of Southern Denmark J.B. Winsløwsvej 9B, DK–5000 Odense C (Denmark) Tel. +45 6550 3380, Fax +45 6550 3682, E-Mail [email protected] © 2008 S. Karger AG, Basel Accessible online at: www.karger.com/dem D ow nl oa de d by : 54 .7 0. 40 .1 1 11 /1 8/ 20 17 3 :0 7: 31 A M Engberg/Christensen/ Andersen-Ranberg/Jeune Dement Geriatr Cogn Disord 2008;26:153–160 154 abilities among cohorts of Okinawan centenarians from the 1970s to the 1990s. Cognitive performance declined more among community-dwelling centenarians than among those living in institutions [9] . In the present investigation, we compared cognitive function as assessed using the Mini-Mental State Examination (MMSE) in 2 birth cohorts of centenarians born 10 years apart in Denmark. The MMSE has been employed in several other centenarian studies, despite the problems of vision and hearing impairment in this extreme age group [10–14] , and represents a commonly accepted psychometric test in the research of cognition and dementia [5] . With about 42% more of the 1905 cohort making it to 100 years compared to the 1895 group, we tested whether the younger cohort would display worse cognitive performance than the older one. The study also focused on differential trends according to sex and housing.