TitlePulmonary function as a risk factor for dementia death: an individual participant meta-analysis of six UK general population cohort studies.
Publication TypeJournal Article
Year of Publication2015
AuthorsRuss, TC, Starr, JM, Stamatakis, E, Kivimäki, M, Batty, GD
JournalJ Epidemiol Community Health
Volume69
Issue6
Pagination550-6
Date Published06/2015
ISSN1470-2738
KeywordsAdult, Aged, Cohort Studies, Dementia, England, Female, Forced Expiratory Volume, Health Surveys, Humans, Lung, Male, Middle Aged, Peak Expiratory Flow Rate, Proportional Hazards Models, Risk Factors, Scotland, Spirometry, Vital Capacity
Abstract
 

BACKGROUND: In addition to being associated with all-cause mortality and cardiovascular disease mortality, lung function has been linked with dementia. However, existing studies typically provide imprecise estimates due to small numbers of outcome events and are based on unrepresentative samples of the general population.

METHODS: Individual participant meta-analysis of six cohort studies from the Health Survey for England and the Scottish Health Survey (total N=54 671). Dementia-related mortality was identified by mention of dementia on any part of the death certificate (mean follow-up 11.7 years). Study-specific Cox proportional hazard models of the association between lung function and dementia-related death were pooled using random effect meta-analysis to produce overall results.

RESULTS: There was a dose-response association between poorer lung function and a higher risk of dementia-related death (age- and sex-adjusted HR compared to highest quartile of forced expiratory volume in 1 s (FEV1), 95% CI: second quartile 1.32, 0.99 to 1.76; third quartile 1.78, 1.30 to 2.43; fourth (lowest) quartile 2.74, 1.73 to 4.32). There was no significant heterogeneity in study-specific estimates (I(2)=0%). Controlling for height, socioeconomic status, smoking and general health attenuated but did not remove the association (second quartile 1.15, 0.82 to 1.62; third quartile 1.37, 0.96 to 1.94; fourth quartile 2.09, 1.17 to 3.71). Results for forced vital capacity and peak flow were similar.

CONCLUSIONS: In these general population samples, the relation between three measures of lung function and dementia death followed a dose-response gradient. Being in the bottom quartile of lung function was associated with a doubling of the risk.

DOI10.1136/jech-2014-204959
Alternate JournalJ Epidemiol Community Health
PubMed ID25691274
Grant ListK013351 / / Medical Research Council / United Kingdom
/ / Biotechnology and Biological Sciences Research Council / United Kingdom
MR/K026992/1 / / Medical Research Council / United Kingdom
MR/K013351/1 / / Medical Research Council / United Kingdom
G0700704 / / Medical Research Council / United Kingdom
R01AG034454 / AG / NIA NIH HHS / United States
R01HL036310 / HL / NHLBI NIH HHS / United States