Improvement in physical functioning protects against cognitive decline: A 6-year follow-up in the Maastricht Aging Study

Abstract

Aging people show deterioration in a variety of functions. Knowledge about factors that may delay this deterioration is crucial for identifying causal pathways and potential intervention strategies. Physical fitness has been proposed to be such a factor, but longitudinal studies have been scarce. This study determined the influence of physical functioning on cognitive performance both cross-sectionally and longitudinally over a period of 6 years in a healthy adult population sample. Data were used from a longitudinal study involving 703 participants in the age range of 24–86 years, as part of the Maastricht Aging Study (MAAS). Physical functioning was measured with the SF-36 health questionnaire. Participants were tested using cognitive tests of verbal memory, executive functioning, reaction time and information processing speed, both at baseline and at a 6-year follow-up examination. At baseline, physical functioning was positively associated with scores on test of executive functioning. Participants with an increase in physical functioning were less likely to experience cognitive decline during the 6 years of follow-up. After correction for age, sex, educational level, baseline physical functioning and cognitive performance, physical functioning at follow-up was still positively associated with scores on tests for executive functioning (Stroop-interference) and information processing speed (Letter-Digit Substitution Test). The observed effects remained unchanged when six participants who developed a neurodegenerative disorder during the course of the study were excluded. Physical functioning has a significant positive effect on cognitive performance after 6 years in normally aging adults.