Age and cognitive decline in the UK Biobank

• Published in: PloS one Vol. 14; no. 3; p. e0213948
• Main Authors: Cornelis, Marilyn C., Wang, Yamin, Holland, Thomas, Agarwal, Puja, Weintraub, Sandra, Morris, Martha Clare
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 18.03.2019; Public Library of Science (PLoS)
• Subjects: Adult; Adults; Age; Aged; Aging; Aging (Biology); Aging - psychology; Alcohol use; Biological Specimen Banks; Biology and Life Sciences; Cognition; Cognition & reasoning; Cognitive ability; Cognitive disorders; Cognitive Dysfunction - epidemiology; Cognitive Dysfunction - psychology; Cohort Studies; Cross-Sectional Studies; Educational attainment; Family medical history; Female; Gender differences; Health aspects; Health care; Humans; Intelligence; Longitudinal Studies; Male; Medicine and Health Sciences; Memory; Memory, Episodic; Middle Aged; Multivariate Analysis; Neuropsychological Tests; Older people; People and Places; Population; Population decline; Preventive medicine; Psychiatry; Psychological aspects; Reaction Time; Regression analysis; Regression models; Research and Analysis Methods; Risk factors; Social Sciences; Sociodemographics; Studies; Substitution reactions; United Kingdom - epidemiology; Vitamin E; United Kingdom; Chicago Illinois; United Kingdom > UK; United States > US; Illinois
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0213948

Age-related cognitive decline is a well-known phenomenon after age 65 but little is known about earlier changes and prior studies are based on relatively small samples. We investigated the impact of age on cognitive decline in the largest population sample to date including young to old adults. Between 100,352 and 468,534 participants aged 38-73 years from UK Biobank completed at least one of seven self-administered cognitive functioning tests: prospective memory (PM), pairs matching (Pairs), fluid intelligence (FI), reaction time (RT), symbol digit substitution, trail making A and B. Up to 26,005 participants completed at least one of two follow-up assessments of PM, Pairs, FI and RT. Multivariable regression models examined the association between age (<45[reference], 45-49, 50-54, 55-59, 60-64, 65+) and cognition scores at baseline. Mixed models estimated the impact of age on cognitive decline over follow-up (~5.1 years). FI was higher between ages 50 and 64 and lower at 65+ compared to <45 at baseline. Performance on all other baseline tests was lower with older age: with increasing age category, difference in test scores ranged from 2.5 to 7.8%(P<0.0001). Compared to <45 at baseline, RT and Pairs performance declined faster across all older age cohorts (3.0 and 1.2% change, respectively, with increasing age category, P<0.0001). Cross-sectional results yielded 8 to 12-fold higher differences in RT and Pairs with age compared to longitudinal results. Our findings suggest that declines in cognitive abilities <65 are small. The cross-sectional differences in cognition scores for middle to older adult years may be due in part to age cohort effects.