Cognitive Function, Physical Performance, Health, and Disease: Norms From the Georgia Centenarian Study

Abstract

This study provides, for the first time, normative data on cognitive functioning and physical performance, health and health behaviors, and diseases from a population-based sample of 244 centenarians and near-centenarians (M age = 100.5 years, range 98-108, 84.8% women, 21.3% African American) from the Georgia Centenarian Study. Data are presented by the four key dimensions of gender, race, residence, and educational attainment. Results illustrate the profound range of functioning in this age group and indicate considerable differences as a function of each dimension. Bivariate models generally suggest that cognitive functioning and physical performance is higher for: men than women; whites than African Americans; community than facility residents; those with more than high school education than those with less than high school education. Multivariate models elaborate that differences in educational attainment generally account for the largest proportion of variance in cognitive functioning and residential status generally accounts for the largest proportion of variance in physical performance measures. Addition of health variables seldom increases variance accounted for in each domain beyond these four dimensions.Centenarians provide an excellent model for aging by virtue of the fact that they have come very close to reaching the maximum lifespan. They afford an opportunity to examine questions about both normal and pathological components of aging and longevity. Although they represent an ever growing proportion of the older adult population, centenarians remain NIH Public Access Author ManuscriptExp Aging Res. Author manuscript; available in PMC 2011 October 1. NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript extremely rare. Most publicly available data resources on aging include data from few, if any, centenarians. Even fewer provide information across a wide range of content areas including physical and functional capacity, cognition, and diseases.Exceptional longevity is a heterogeneous phenotype. Sebatiani and colleagues (2010) recently reported that even the genetics of exceptional longevity are complex. Their genome wide association scan identified 150 single nucleotide polymorphisms (SNPs) which were more common in centenarians than controls. These SNPs could be further clustered into 19 different genotypes. These genotypes, in turn, had different associations with age at death, likelihood of age-associated diseases, and age of disease onset.To date, we know very little about the extent of heterogeneity in cognitive function, physical performance, health and health behaviors, and diseases among centenarians, particularly in the population-based context and differences across major demographic variables such as gender, race, residential status, and educational attainment. Two previous papers in Experimental Aging Research have included extensive normative data on neuropsychological test performance with stratification by multiple age groups and education (Dore et al.,...

Normative Data for the Cognitively Intact Oldest-Old: The Framingham Heart Study

“…Results concerning the 90+ age band should be considered cautiously as there were only 57 participants in this age band; this information was included despite this limitation because it highlights the range of ages within the FHS sample. The number of individuals in this group is likely to grow and will be included in future studies; it is of interest that though this data is preliminary, cognition does appear to continue to change at this advanced age, which supports recent studies of cognitive changes even among centenarians (Davey et al, 2013; Davey et al, 2010; Miller et al, 2010). These results are generally similar to those reported by Welsh-Bohmer and colleagues and Elias and co-authors (Elias et al, 2011; Welsh-Bohmer et al, 2009).…”

“…For example, Ahl and coauthors (2013) found that in the Framingham Offspring cohort, MCI as defined by WRAT-adjusted as compared to education-adjusted norms was more strongly associated with incident dementia for all cognitive tests examined (Ahl et al, 2013). Their suggestion of using reading level as a more accurate surrogate than years of formal education has been supported by other studies of the oldest-old (Davey et al, 2013; Davey et al, 2010; Elias et al, 2011). The influence of reading level on cognitive performance has been found in other populations as well.…”

“…Gender differences in verbal fluency and visuospatial skills have been supported previously with women generally outperforming men (fluency) and men generally outperforming women (visuospatial skills). While gender differences in extreme aging have been suggested in the literature, particularly that men who do reach extreme age fare better physically and cognitively than women of the same age (Andersen, Sebastiani, Dworkis, Feldman, & Perls, 2012; Xie, Matthews, Jagger, Bond, & Brayne, 2008) (Davey et al, 2010), multiple studies have found that gender effects may be attributable to effects of education and age (Beeri et al, 2006; Davey et al, 2010; Dore, Elias, Robbins, Elias, & Brennan, 2007; Elias et al, 2011; Kenny et al, 2013; Welsh-Bohmer et al, 2009). Indeed, in the current study, there are large educational differences between age bands (e.g., 16–43% of individuals in the oldest-old age bands, where the proportion of women is higher, with less than high school education compared to 3–10% of young-old individuals, where the proportion of women to men is nearly equivalent, with less than high school education), although the interaction reported was not a result of educational differences.…”

“…In a sample of HIV+ and HIV− women, Manly and coauthors (2011) found that reading level as defined by the WRAT-III had the strongest relationship to cognitive performance, compared to HIV status, education, and in some cases, age (Manly et al, 2011). However, the majority of studies of cognition in the oldest-old do use education as a marker for premorbid ability and it is often found to be a significant predictor of cognitive performance (Beeri et al, 2006; Coluccia et al, 2011; Davey et al, 2010; Dore et al, 2007; Kenny et al, 2013; Miller et al, 2010; Stein et al, 2012; Welsh-Bohmer et al, 2009), though a study of verbal fluency performance in elderly individuals found no significant differences based on reading ability or education (Ravdin et al, 2003). We do provide age- and education-based normative data in the supplementary materials as we know that clinicians more often have access to years of education than WRAT Reading performance.…”

“…Davey and coauthors provided normative data by gender, race, education and residential status on additional neuropsychological and physical measures (Finger Tapping Test (FTT), WAIS Similarities, MMSE, BDS, Controlled Oral Word Association Test (COWAT), SIB, the Global Deterioration Scale, the Field Object Memory Exam (FOME)) and physical measures for the same sample as described by Miller and colleagues (Davey et al, 2010). They found that cognitive and physical performances were better for men than women, whites than African Americans, community than facility residents, and those with more than high school education than those with less than high school education.…”