A Droplet Digital PCR Assay for Smoking Predicts All-Cause Mortality
Year: 2018
Type: article
Study design: Observational Study
Abstract: OBJECTIVES: -Determine whether an epigenetic assay for smoking predicts all-cause mortality in adults participating in a longitudinal study of Iowa adoptees. BACKGROUND: -Improved biomarkers for smoking are needed given its large public health impact and significant limitations of both self-report and current biomarkers, such as cotinine in detecting smoking. In the past 5 years, multiple epigenome-wide association studies of smoking have identified loci suitable for translation as epigenetic biomarkers for smoking, in particular the CpG cg05575921. Digital polymerase chain reaction methods hold promise for the development of this and other epigenetic biomarkers. METHODS: -Participants in the Iowa Adoption Studies were interviewed regarding their smoking habits. DNA was prepared from whole blood and bisulfite-converted for methylation analysis and digital droplet polymerase chain reaction assay of methylation at cg05575921 was performed. National Death Index records were requested for 584 study participants, resulting in 24 complete matches, 210 partial matches and 350 non-matching records. Complete matches were coded as deceased while the remainder were coded as alive (ie, censored). In total, methylation data and vital status information were available for a total of N = 193 subjects, including 15 deceased and 178 non-deceased. Cox regression was used to examine the ability of cg05575921 methylation as a continuous value to predict the timing of mortality with and without the inclusion of age, sex, race, BMI, marital status, educational status, socioeconomic status, cardiovascular risk factors, and a history of cancer as covariates. RESULTS: -Methylation at cg05575921 predicted the hazard of mortality as the sole predictor and after accounting for major demographic and clinical risk factors. The fitted model showed the hazard ratio increased by 3.5% for every 1% decrease in methylation. CONCLUSIONS: -Decreased methylation at cg05575921, an emerging epigenetic biomarker for smoking, was associated with early mortality in a longitudinal study of adults after accounting for the impact of major demographic and clinical risk factors for all-cause mortality. This approach may be useful in clinical research or actuarial assessments.
Source: Journal of Insurance Medicine
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: green
Awards: The Relationship of AHRR Methylation to Risky Adolescent Behaviors, A Saliva DNA based Epigenetic Test for Adolescent Smoking, A Quantitative Epigenetic Test for Guiding Smoking Cessation Therapy, The Iowa Neuroscience Specialty Program in Research Education (INSPIRE), AACAP Physician Scientist Program in Substance Use
OpenAlex ID: W2913874567