Table 3. Association between quartiles of betaine intake and lung cancer risk.
Models | Quartiles of betaine intake | P** trend | ||||
1 | 2 | 3 | 4 | |||
Case n (%) | 911 (55.51) | 713 (49.38) | 650 (47.07) | 547 (42.80) | ||
Control n(%) | 730 (44.49) | 731 (50.62) | 731 (52.93) | 731 (57.20) | ||
Overall | ||||||
Reduceda | OR (95% CI) | 1.00 | 0.83 (0.71–0.96) | 0.78 (0.67–0.90) | 0.67 (0.58–0.79) | <0.0001 |
Poverall | <0.0001 | |||||
Completeb | OR (95% CI) | 1.00 | 0.85 (0.73–1.00) | 0.81 (0.69–0.95) | 0.71 (0.61–0.84) | <0.0001 |
P* overall | 0.0006 | |||||
Stratified by smoking status | ||||||
Never Smokers | ||||||
Reducedc | OR (95% CI) | 1.00 | 1.07 (0.73–1.57) | 0.87 (0.59–1.27) | 1.00 (0.69–1.45) | 0.702 |
P* overall | 0.635 | |||||
Completed | OR (95% CI) | 1.00 | 1.06 (0.72–1.57) | 0.86 (0.58–1.28) | 1.03 (0.70–1.52) | 0.869 |
P* overall | 0.614 | |||||
Former Smokers | ||||||
Reducedc | OR (95% CI) | 1.00 | 0.92 (0.73–1.16) | 0.83 (0.66–1.05) | 0.71 (0.56–0.89) | 0.002 |
P* overall | 0.023 | |||||
Completed | OR (95% CI) | 1.00 | 0.95 (0.74–1.21) | 0.86 (0.67–1.11) | 0.75 (0.59–0.96) | 0.017 |
P* overall | 0.112 | |||||
Current Smokers | ||||||
Reducedc | OR (95% CI) | 1.00 | 0.70 (0.55–0.88) | 0.75 (0.59–0.95) | 0.51 (0.39–0.66) | <0.0001 |
P* overall | <0.0001 | |||||
Completed | OR (95% CI) | 1.00 | 0.73 (0.57–0.93) | 0.80 (0.62–1.02) | 0.55 (0.42–0.73) | 0.0001 |
P* overall | 0.0003 |
Adjusted for sex, race/ethnicity, age, pack-years, total caloric intake, smoking status.
Adjusted for sex, race/ethnicity, age, pack-years, total caloric intake, family cancer history, dust exposure, second-hand smoke, emphysema, hay fever, asthma, addiction index, alcohol, time since smoking cessation, smking status.
Adjusted for sex, race/ethnicity, age, pack-years, total caloric intake.
Adjusted for sex, race/ethnicity, age, pack-years, total caloric intake, family cancer history, dust exposure, second-hand smoke, emphysema, hay fever, asthma, addiction index, alcohol, time since smoking cessation.
p-value, chi-square test using quartiles of betaine intake as categorical variable.
p-value, test for linear trend using quartiles of betaine intake as continuous variable.