Table 5.
Effects of interactions between HP infection, CagA status, and PRKAA1 rs13361707 polymorphisms on the risk of gastric cancer
| rs13361707 genotype | HP infection/CagA status | ORsa (95% CI) for positive/negative within strata of genotype | ORsa (95% CI) for both positive within strata of genotype | ||
|---|---|---|---|---|---|
| Both negative | Positive/negative | Both positive | |||
| ORa (95% CI) | ORa (95% CI) | ORa (95% CI) | |||
| T/T | 1.00 (ref.) | 1.21 (0.63, 2.33) | 1.13 (0.71, 1.78) | 1.21 (0.63, 2.33) | 1.13 (0.71, 1.78) |
| T/C+C/C | 1.16 (0.75, 1.81) | 2.20 (1.37, 3.54) | 1.81 (1.21, 2.72) | 1.90 (1.31, 2.75) | 1.56 (1.18, 2.05) |
| ORsa (95% CI) for genotype within strata of HP infection status | 1.16 (0.75, 1.81) | 1.83 (0.97, 3.44) | 1.15 (0.71, 1.86) | ||
| RERIb (95% CI) | 0.83 (−0.12, 1.77) | 0.50 (0.30, 0.70) | |||
| P = 0.087 | P < 0.001 | ||||
| Ratio of ORsc (95% CI) | 1.54 (0.71, 3.31) | 1.38 (0.79, 2.41) | |||
| P = 0.274 | P = 0.261 | ||||
OR, odds ratio; RERI, relative excess risk due to interaction.
a
ORs were adjusted for age, sex, cumulative smoking amount, alcohol intake amount, body mass index, and education level.
b
RERI > 0 indicates an additive interaction.
c
Ratio of ORs measures the interactions on a multiplicative scale.