Systematic review of lung function and COPD with peripheral blood DNA methylation in population based studies.
Epigenetic variations in peripheral blood have potential as biomarkers for disease. This systematic review assesses the association of lung function and chronic obstructive pulmonary disease (COPD) with DNA methylation profiles in peripheral blood from population-based studies.



Online databases Medline, Embase, and Web of Science were searched. Google Scholar was searched to identify grey literature. After removing duplicate articles, 1155 articles were independently screened by two investigators. Peer reviewed reports on population-based studies that examined peripheral blood DNA methylation in participants with measured lung function (FEV1, FEV1/FVC ratio) or known COPD status were selected for full-text review. Six articles were suitable for inclusion. Information regarding study characteristics, designs, methodologies and conclusions was extracted. A narrative synthesis was performed based on published results.



Three of the six articles assessed the association of COPD with DNA methylation, and two of these also included associations with lung function. Overall, five reports examined the association of lung function with DNA methylation profiles. Five of the six articles reported 'significant' results. However, no consistent CpG sites were identified across studies for COPD status or lung function values.



DNA methylation patterns in peripheral blood from individuals with reduced lung function or COPD may be different to those in people with normal lung function. However, this systematic review did not find any consistent associations of lung function or COPD with differentially methylated CpG sites. Large studies with a longitudinal design to address reverse causality may prove a more fruitful area of research.



PROSPERO 2016: CRD42016037352 .
School of Medicine, Imperial College London, London, UK.
Matthew
M
Machin
Population Health and Occupational Disease, NHLI, Imperial College London, London, UK. a.amaral@imperial.ac.uk.|MRC-PHE Centre for Environment and Health, Imperial College London, London, UK. a.amaral@imperial.ac.uk.
André F S
AF
Amaral
MRC-PHE Centre for Environment and Health, Imperial College London, London, UK.|Department of Epidemiology and Biostatistics, School of Public Health, Imperial College London, London, UK.
Matthias
M
Wielscher
Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, UK.
Faisal I
FI
Rezwan
Swiss Tropical and Public Health Institute, Basel, Switzerland.|University of Basel, Basel, Switzerland.
Medea
M
Imboden
MRC-PHE Centre for Environment and Health, Imperial College London, London, UK.|Department of Epidemiology and Biostatistics, School of Public Health, Imperial College London, London, UK.
Marjo-Riitta
MR
Jarvelin
Airways Disease Section, NHLI, Imperial College London, London, UK.
Ian M
IM
Adcock
Swiss Tropical and Public Health Institute, Basel, Switzerland.|University of Basel, Basel, Switzerland.
Nicole
N
Probst-Hensch
Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, UK.
John W
JW
Holloway
Population Health and Occupational Disease, NHLI, Imperial College London, London, UK.|MRC-PHE Centre for Environment and Health, Imperial College London, London, UK.
Deborah L
DL
Jarvis
D019175:DNA Methylation; D044127:Epigenesis, Genetic; D006801:Humans; D029424:Pulmonary Disease, Chronic Obstructive / Q000503:physiopathology*; D012129:Respiratory Function Tests
COPD; DNA methylation; Epigenetics; Lung function; Peripheral blood