Table 2. CHRNA4 R336Ca confers risk of heavy smoking and smoking-related diseases.
| Phenotype | Eff/OR | P-value |
Cases |
Controls |
||
|---|---|---|---|---|---|---|
| N chip | N rel | N chip | N rel | |||
| FTND score (mild, moderate, severe) | 0.85b | 1.2 × 10−4 | 18 592 | 2706 | — | — |
| CPD in smokers | 3.0 CPD | 1.8 × 10−4 | 34 200 | 6373 | — | — |
| HSI score 4+ vs low-quantity smokersc | 4.77 | 2.1 × 10−5 | 1713 | 31 | 13 948 | 1.064 |
| LC | 2.29 | 4.0 × 10−4 | 1437 | 2572 | 84 086 | 137 443 |
| Early-onset LC | 4.49 | 2.2 × 10−4 | 245 | 583 | 85 273 | 129 010 |
| PAD | 1.66 | 0.090 | 1926 | 961 | 81 992 | 109 548 |
| Early-onset PAD | 3.47 | 9.2 × 10−3 | 447 | 81 | 70 988 | 69 570 |
| COPD | 1.91 | 9.3 × 10−4 | 3857 | 3639 | 87 510 | 207 914 |
| Early-onset COPD | 3.22 | 2.9 × 10−4 | 1033 | 437 | 64 979 | 73 138 |
| AAAs | 1.98 | 0.12 | 574 | 686 | 83 349 | 122 962 |
| Early-onset AAA | 6.44 | 6.3 × 10−3 | 92 | 112 | 83 831 | 123 536 |
| All smoking-related diseases | 1.87 | 6.8 × 10−5 | 6594 | 6910 | 84 776 | 225 225 |
| All smoking-related diseases early onset | 3.48 | 2.1 × 10−7 | 1704 | 1178 | 83 818 | 138 837 |
Abbreviations: AAA, abdominal aortic aneurysm; COPD, chronic obstructive pulmonary disease; CPD, cigarettes smoked per day; FTND, Fagerström Test of Nicotine Dependence; HSI, heavy smoking index; LC, lung cancer; OR, odds ratio; PAD, peripheral artery disease; SNP, single-nucleotide polymorphism.
Table 2 shows the results of association analyses of two quantitative traits, nicotine dependence (FTND score) and smoking quantity (CPD), and case–control comparisons for a number of smoking-related diseases. Shown are, for each of the phenotypes listed, the effect sizes (Eff) for quantitative traits or ORs for case–control comparisons, the P-value and for both cases and controls, the number of subjects included in analysis, chip-typed individuals (N chip) and those with at least one first- or second-degree relative typed (N rel). The inflation factors for the various analyses listed are provided in the Supplementary Material.
The SNP encoding R336C (rs56175076) has position 61 452 201 on chromosome 20 according to build 36 (hg18).
Effect size from analysis multiplied by 3.5, the difference in FTND score between the category midpoints; for information on the FTND analysis see Materials and Methods.
HSI29 vs smokers smoking 10 CPD or less.