Lung function and cognitive ability in a longitudinal birth cohort study.
OBJECTIVE
The objective of this study was to examine the association between forced expiratory volume in 1 second (FEV1) and cognitive ability in midlife in the normal population.


METHODS
Multiple regression was used to test associations between FEV1 and cognitive function in 1778 men and women in the MRC National Survey of Health and Development, also known as the British 1946 birth cohort. Analyses were adjusted for sex, body size (birth weight, adult height, weight, and chest circumference), socioeconomic status, lifetime smoking, and a range of health indicators, including early respiratory vulnerability (infant lower respiratory infection, childhood asthma, and exposure to atmospheric pollution).


RESULTS
FEV1 at 43 years was associated with slower psychomotor speed (peg placement) at the same age and with slower decline in psychomotor speed (letter search speed) from 43 to 53 years, independently of the previously mentioned potential confounders. These independent associations were not observed, however, for adult verbal ability, verbal memory, or rate of decline in memory, which were significantly explained by socioeconomic status and adolescent cognitive ability. In a subsequent analysis, adolescent cognition was positively associated with FEV1, although not with rate of decline in FEV1 from 43 to 53 years, again independently of the previously mentioned confounders.


CONCLUSIONS
Cognitive function and FEV1 are positively associated across the life course. One possible explanation lies in the parallel action of endocrine, autonomic, and motor control systems on respiration and higher mental function. Because respiration and mental function are both associated with functional capacity and survival, this is a matter of potential clinical significance.
Richards
Marcus
M
MRC National Survey of Health and Development, University College London, UK. m.richards@ucl.ac.uk
Strachan
David
D
Hardy
Rebecca
R
Kuh
Diana
D
Wadsworth
Michael
M
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D003071:Cognition / Q000502:physiology*; D003710:Demography; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012959:Socioeconomic Factors; D013647:Task Performance and Analysis