Table 1.

Comparisons of Proportion DNA Methylation at CpG Sites within the CDH1 Genomic Region

CpG Site ID	Chr	UCSC RefGene Name	UCSC RefGene Group	Stand hg38	Effect.Size	SE	P Value	gc. P Value
cg10313337	16	CDH1	Body	+	0.040	0.015	0.009	0.009
cg05303053	16	CDH1	Body	−	0.011	0.011	0.306	0.306
cg20750889	16	CDH1	Body	−	−0.001	0.013	0.937	0.937
cg00632260	16	CDH1	Body	−	−0.008	0.011	0.440	0.440
cg25218831	16	CDH1	Body	−	−0.011	0.017	0.528	0.528

Definition of abbreviations: Chr = chromosome; COPD = chronic obstructive pulmonary disease; CpG = cytosine–guanine dinucleotide; gc = genomic control; SPIROMICS = Subpopulations and Intermediate Outcomes in COPD Study; UCSC = University of California, Santa Cruz.

β-methylation for five CpG sites within the CDH1 genomic region was compared between 36 SPIROMICS patients with moderate to severe COPD and 36 SPIROMICS patients without COPD or with mild COPD who had DNA isolated from lower airway epithelial cells from research bronchoscopic brushings. Regression-based models included age, sex, body mass index, smoking pack-years, current smoking status, and first five principal components of ancestry. DNA methylation at one CpG near the CDH1 enhancer D region (chr16: 68789786–68789788, cg10313337) was significantly increased in the DNA from epithelial cells from patients with moderate-to-severe COPD compared with cells from control patients and those with mild COPD. Bold value represents a region of significance. The “+” and “−” refer to the positive and negative DNA strands.