Frequencies of individual SNPs of the NK-2R gene in relation to capsaicin sensitivities of patients with chronic cough
| Capsaicin sensitivity§ | p value* | ||
|---|---|---|---|
| Positive(N = 146) | Negative(N = 166) | ||
| *χ2 test (positive v negative capsaicin sensitivity). | |||
| †Positive skin test responses to one or more common aeroallergens. | |||
| ‡A recessive model of an allele (Glu/Glu v other alleles); OR 1.69 (95% CI 1.18 to 2.42) by multiple logistic regression analysis after adjusting for confounders such as age, sex, smoking history, and atopy. | |||
| §C5 ⩽16 μM/l. | |||
| Mean (range) age (years) | 50.1 (20–79) | 49.1 (15–87) | 0.56 |
| Sex (F/M) | 104/42 | 100/66 | 0.04 |
| Smoker (%) | 19.3 | 23.8 | 0.32 |
| Atopy‡ (%) | 30.8 | 25.5 | 0.32 |
| Gly231Glu, N (%) | |||
| Gly/Gly | 45 (32.6%) | 62 (40.0%) | |
| Gly/Glu | 56 (40.6%) | 75 (48.4%) | 0.004 |
| Glu/Glu | 37 (26.8%) | 18 (11.6%) | |
| Arg375His, N (%) | |||
| Arg/Arg | 114 (83.2%) | 115 (74.7%) | |
| Arg/His | 20 (14.6%) | 36 (23.4%) | 0.12 |
| His/His | 3 (2.2%) | 3 (1.9%) | |