F2RL3 Methylation as a Biomarker of Current and Lifetime Smoking Exposures

http://dx.doi.org/10.1289/ehp.1306937

Table 3. Association between smoking behavior and F2RL3 (CpG_4) methyla­tion intensity.
Smoking characteristic Model 1a Model 2b
Regression coefficient (95% CI) p‑Value Regression coefficient (95% CI) p‑Value
aLinear regression without adjustment. bLinear regression, adjusted for sex, age, BMI (underweight/normal weight/overweight/obesity), physical activity (inactive/low/medium and high), prevalence of cardiovascular disease and ­diabetes, and batch effect.
Smoking status        
Never smoker Reference   Reference  
Former smoker –0.059 (–0.066, –0.053) < 0.0001 –0.051 (–0.058, –0.044) < 0.0001
Current smoker –0.185 (–0.193, –0.177) < 0.0001 –0.181 (–0.189, –0.173) < 0.0001
Current intensity of smoking (average number of cigarettes/day)        
0 (never and former smokers) Reference   Reference  
1–9 –0.088 (–0.107, –0.069) < 0.0001 –0.093 (–0.111, –0.074) < 0.0001
10–19 –0.181 (–0.196, –0.166) < 0.0001 –0.178 (–0.192, –0.164) < 0.0001
20–29 –0.179 (–0.191, –0.167) < 0.0001 –0.177 (–0.189, –0.166) < 0.0001
30–60 –0.218 (–0.237, –0.200) < 0.0001 –0.210 (–0.228, –0.192) < 0.0001
Cumulative dose of smoking (pack-years)        
0 (never smokers) Reference   Reference  
0.2–9 –0.024 (–0.035, –0.013) < 0.0001 –0.025 (–0.036, –0.014) < 0.0001
10–19 –0.067 (–0.078, –0.057) < 0.0001 –0.067 (–0.078, –0.057) < 0.0001
20–29 –0.123 (–0.134, –0.113) < 0.0001 –0.123 (–0.133, –0.113) < 0.0001
30–147 –0.169 (–0.178, –0.161) < 0.0001 –0.171 (–0.179, –0.162) < 0.0001
Time since cessation of smoking (years)        
0 (current smokers) Reference   Reference  
1 0.022 (–0.006, 0.050) 0.12 0.019 (–0.007, 0.046) 0.16
2–4 0.068 (0.049, 0.086) < 0.0001 0.071 (0.053, 0.088) < 0.0001
5–9 0.074 (0.058, 0.090) < 0.0001 0.079 (0.064, 0.094) < 0.0001
10–19 0.120 (0.108, 0.131) < 0.0001 0.121 (0.111, 0.132) < 0.0001
20–50 0.163 (0.152, 0.173) < 0.0001 0.171 (0.161, 0.181) < 0.0001