Table 4.
Genotype frequencies of chitinase polymorphisms in the LHS cohort and their associations with lung function
| Caucasians | ||||||||||
| Gene | Polymorphism | Genotype | N | Baseline FEV1a | P value |
P value Additive model |
N | Rate of FEV1 Declineb | P value |
P value Additive model |
| CHIA | rs3818822 | GG | 3112 (80%) | 78.64 ± 0.16 | Reference | 0.3124 | 3407 (82%) | −0.96 ± 0.03 | Reference | 0.6681 |
| AG | 715 (18%) | 78.61 ± 0.35 | 0.0521 | 709 (17%) | −1.01 ± 0.07 | 0.7526 | ||||
| AA | 51 (1%) | 76.01 ± 1.10 | 0.0291 | 49 (1%) | −0.94 ± 0.21 | 0.8993 | ||||
| CHIA | G339T | GG | 2493 (76%) | 78.40 ± 0.18 | Reference | 0.8344 | 2448 (76%) | −0.97 ± 0.04 | Reference | 0.6766 |
| GT | 728 (22%) | 78.52 ± 0.34 | 0.7279 | 715 (22%) | −1.05 ± 0.07 | 0.2743 | ||||
| TT | 58 (2%) | 78.01 ± 1.16 | 0.8179 | 54 (2%) | −0.83 ± 0.24 | 0.4065 | ||||
| CHIT1 | rs2494303 | CC | 2328 (65%) | 78.32 ± 0.18 | Reference | 0.0605 | 2328 (65%) | −1.02 ± 0.04 | Reference | 0.7693 |
| AC | 1128 (31%) | 78.99 ± 0.27 | 0.6554 | 1128 (31%) | −0.88 ± 0.05 | 0.0021 | ||||
| AA | 132 (4%) | 79.13 ± 0.82 | 0.5729 | 132 (4%) | −1.35 ± 0.16 | 0.0121 | ||||
| CHI3L1 | rs4950928 | CC | 2466 (64%) | 78.52 ± 0.18 | Reference | 0.3671 | 2420 (64%) | −0.98 ± 0.04 | Reference | 0.6294 |
| CG | 1216 (32%) | 78.75 ± 0.25 | 0.9689 | 1193 (32%) | −0.95 ± 0.05 | 0.971 | ||||
| GG | 145 (4%) | 78.84 ± 0.76 | 0.67 | 144 (4%) | −0.94 ± 0.15 | 0.8293 | ||||
| African Americans | ||||||||||
| Gene | Polymorphism | Genotype | N | Baseline FEV1a | P value |
P value Additive model |
N | Rate of FEV1 Declineb | P value |
P value Additive model |
| CHIA | rs3818822 | GG | 84 (65%) | 76.87 ± 1.05 | Reference | 0.7405 | 83 (64%) | −1.25 ± 0.28 | Reference | 0.1490 |
| AG | 43 (33%) | 76.40 ± 1.27 | 0.8731 | 42 (33%) | −0.53 ± 0.39 | 0.1476 | ||||
| AA | 2 (2%) | 74.30 ± 4.90 | Excluded | 2 (2%) | −0.53 ± 0.55 | Excluded | ||||
| CHIA | G339T | GG | 85 (75%) | 76.25 ± 1.00 | Reference | 0.5498 | 83 (74%) | −0.92 ± 0.24 | Reference | 0.0348 |
| GT | 24 (21%) | 76.31 ± 1.89 | 0.2096 | 24 (21%) | −0.71 ± 0.42 | 0.005 | ||||
| TT | 5 (4%) | 80.44 ± 3.73 | 0.169 | 5 (4%) | −4.89 ± 3.28 | 0.0005 | ||||
| CHIT1 | rs2494303 | CC | 108 (87%) | 76.50 ± 0.87 | Reference | 0.7211 | 108 (87%) | −0.82 ± 0.21 | Reference | 0.0222 |
| AC | 15 (12%) | 78.18 ± 2.26 | 0.6923 | 15 (12%) | −2.57 ± 1.14 | 0.0075 | ||||
| AA | 1 (1%) | 62.3 | Excluded | 1 (1%) | −0.35 | Excluded | ||||
| CHI3L1 | rs4950928 | CC | 52 (43%) | 75.92 ± 1.45 | Reference | 0.5775 | 52 (43%) | −0.93 ± 0.48 | Reference | 0.3990 |
| CG | 52 (43%) | 76.60 ± 1.23 | 0.8456 | 52 (43%) | −0.98 ± 0.21 | 0.6813 | ||||
| GG | 17 (14%) | 77.54 ± 2.02 | 0.5864 | 16 (13%) | −1.54 ± 0.39 | 0.3694 | ||||
a
Lung function at the start of the study measured as forced expiratory volume in 1 second (FEV1) % of predicted (± standard error).
b
Mean change in lung function per year over a five-year period measured as FEV1 % of predicted (± standard error).