Background
Methods
Study participants
Clinical examination and inflammation measurement
TagSNP selection and genotype determination
Statistical analysis
Descriptive statistics and baseline comparisons
Genetic association analysis
Results
Systemic inflammation
Characteristics
|
Controls
N = 195
|
COPD
N = 355
|
P-value
|
---|---|---|---|
Years of age | 54.3 (7.3) | 64.2 (9.4) | <0.001 |
Male, N (%) | 94 (48) | 219 (62) | 0.002 |
Current smoker, N (%) | 115 (59%) | 90 (25%) | <0.001 |
Tobacco consumption, pack years-smoked | 29.6 (14.8) | 39.9 (18.5) | <0.001 |
FEV1, liters | 3.2 (0.7) | 1.1 (0.5) | <0.001 |
FEV1,%pred | 103.3 (15.1) | 41.9 (16.0) | <0.001 |
FEV1/FVC, % | 78.3 (5.3) | 42.0 (11.9) | <0.001 |
FVC, liters | 4.1 (0.9) | 3.0 (0.9) | <0.001 |
FVC,%pred | 109.3 (16.8) | 86.3 (21.1) | <0.001 |
BMI, kg/m2 | 26.4 (3.7) | 25.0 (5.0) | <0.001 |
Hypertension†, N (%) | 33 (17%) | 88 (25%) | 0.01 |
PaO2, kPa | - | 9.2 (1.37) | |
PaCO2, kPa | - | 5.5 (0.80) | |
Long-term oxygen therapy, N (%) | - | 82 (23.43) | |
6 minute walking distance, meters | - | 420.1 (127.9) | |
Maximum workload, watts | - | 72.6 (33.9) | |
Maximum workload,% pred | - | 56.6 (25.2) | |
MRC dyspnea score | - | 3 (2–4) | |
BODE index | 4.3 (2.1) | ||
Systolic blood pressure, mm/Hg | - | 135.9 (23.31) | |
Diastolic blood pressure, mm/Hg | - | 81.1 (13.09) | |
Charlson co morbidity index‡ | - | 1 (1–8) | |
CRP, mg/L | 1.3 (0.2–3.19) | 4.6 (1.3–11.09) | <0.001 |
IL-6, pg/mL | 0.7 (0.45–1.38) | 2.1 (1.15–4.24) | <0.001 |
Fibrinogen, g/L | 3.3 (3.00–3.60) | 3.6 (3.23–3.82) | <0.001 |
Number of plasma markers
in the top quartile:
| <0.001 | ||
0, N (%) | 155 (79.4%) | 159 (44.5%) | |
1, N (%) | 29 (14.4%) | 88 (24.2%) | |
2–3, N (%) | 10 (5.2%) | 118 (31.3%) | |
CRP < 1 mg/L | 93 (47.9%) | 68 (19.2%) | <0.001 |
CRP 1–3 mg/L | 51 (26.3%) | 81 (22.8%) | |
CRP 3–10 mg/L | 40 (20.6%) | 109 (30.7%) | |
CRP > 10 mg/L | 10 (5.2%) | 97 (27.3%) |
Characteristics
|
CRP ≤ 3 mg/L
N = 146
|
CRP > 3 mg/L
N = 209
|
P-value
|
---|---|---|---|
Years of age | 62.1 (8.2) | 65.7 (9.8) | < 0.001 |
Male, N (%) | 77 (53%) | 142 (68%) | 0.004 |
Current smoker, N (%) | 40 (27%) | 50 (24%) | 0.460 |
Tobacco consumption, pack years-smoked | 40.3 (19.0) | 39.6 (18.2) | 0.703 |
FEV1, liters | 1.1 (0.5) | 1.1 (0.5) | 0.922 |
FEV1,%pred | 41.6 (15.9) | 41.9 (15.9) | 0.846 |
FEV1/FVC, % | 41.0 (11.8) | 42.7 (11.8) | 0.172 |
FVC, liters | 3.0 (1.0) | 3.0 (0.9) | 0.884 |
FVC,%pred | 87.5 (22.5) | 85.4 (20.3) | 0.373 |
BMI, kg/m2 | 24.0 (4.4) | 25.7 (5.4) | 0.001 |
PaO2, kPa | 9.3 (1.5) | 9.1 (1.3) | 0.259 |
PaCO2, kPa | 5.4 (0.8) | 5.5 (0.8) | 0.342 |
Long-term oxygen therapy, N (%) | 30 (21%) | 52 (25%) | 0.205 |
6 minute walking distance, meters | 445.9 (121.2) | 401.1 (129.3) | 0.001 |
Maximum workload, watts | 77.2 (34.7) | 69.2 (33.0) | 0.037 |
Maximum workload,% pred | 57.4 (23.6) | 56.0 (26.4) | 0.636 |
MRC dyspnea score | 2 (2–4) | 3 (2–4) | 0.108 |
BODE index | 4.1 (2.1) | 4.4 (2.1) | 0.264 |
Systolic blood pressure, mm/Hg | 134.7 (21.7) | 136.8 (24.4) | 0.412 |
Diastolic blood pressure, mm/Hg | 80.7 (12.5) | 81.4 (13.5) | 0.647 |
Charlson co morbidity index † | 1 (1–7) | 1 (1–8) | 0.007 |
GOLD stages (%): | |||
Mild | 2.1% | 2.4% | 0.891 |
Moderate | 27.4% | 23.9% | |
Severe | 35.6% | 38.3% | |
Very severe | 34.9% | 35.4% | |
CRP, mg/L | 1.1 (0.6–1.9) | 9.4 (5.8–16.0) | < 0.001 |
IL-6, pg/mL | 1.3 (0.7–2.1) | 3.5 (1.6–5.1) | < 0.001 |
Fibrinogen, g/L | 3.3 (3.0–3.6) | 3.7 (3.4–4.0) | < 0.001 |
Haplotype Tagging SNPs and COPD
dbSNP No. |
tagSNP*
|
Gene region
|
Minor allele frequency
|
P-value alleles†
|
OR adj‡ genotypes
(95%CI)
|
P-value genotypes
| |
---|---|---|---|---|---|---|---|
Controls
|
COPD
| ||||||
IL6 gene
(7p21-p15)
| |||||||
rs2069825 | 205CT/- | 5'flanking | 0.42 | 0.37 | 0.11 | 0.87 (0.64–1.17) | 0.35 |
rs2069827 | 321G/T | 5'flanking | 0.10 | 0.07 | 0.10 | 0.67 (0.39–1.14) | 0.14 |
rs1800797 | 1086G/A | 5'flanking | 0.44 | 0.39 | 0.12 | 0.86 (0.64–1.16) | 0.32 |
rs2069840 | 3437C/G | intron | 0.34 | 0.36 | 0.52 | 1.04 (0.76–1.42) | 0.81 |
rs1554606 | 3572G/T | intron | 0.46 | 0.42 | 0.19 | 0.84 (0.62–1.13) | 0.25 |
rs2069849 | 6021C/T | synonymous | 0.03 | 0.02 | 0.33 | 0.51 (0.19–1.36) | 0.18 |
rs2069861 | 6519C/T | 3'flanking | 0.11 | 0.09 | 0.24 | 0.93 (0.57–1.52) | 0.77 |
rs1818879 | 7592G/A | 3'flanking | 0.32 | 0.39 | 0.02 | 1.49 (1.08–2.04) | 0.01 |
CRP gene
(1q21-q23)
| |||||||
rs3091244 | 1440C/T | 5'flanking | 0.30 | 0.31 | 0.08 | 1.01 (0.73–1.40) | 0.94 |
1440C/A | 0.06 | 0.08 | 1.57 (0.88–2.79) | 0.12 | |||
rs1800947 | 2667G/C | synonymous | 0.05 | 0.08 | 0.03 | 1.80 (0.96–3.37) | 0.06 |
rs1130864 | 3014C/T | 3' UTR | 0.30 | 0.31 | 0.65 | 1.05 (0.76–1.46) | 0.76 |
rs1205 | 3872G/A | 3'-flanking | 0.35 | 0.33 | 0.41 | 0.98 (0.73–1.32) | 0.91 |
rs2808630 | 5237A/G | 3'-flanking | 0.29 | 0.27 | 0.55 | 0.83 (0.60–1.15) | 0.27 |
rs3090077 | 6469A/C | 3'-flanking | 0.05 | 0.08 | 0.15 | 1.59 (0.86–2.96) | 0.14 |
FGB gene
(4q28)
| |||||||
rs1800791 | 1038G/A | 5' flanking | 0.18 | 0.17 | 0.63 | 0.80 (0.55–1.18) | 0.26 |
rs1800788 | 1643C/T | 5' flanking | 0.18 | 0.21 | 0.31 | 1.36 (0.94–1.95) | 0.10 |
rs1800787 | 1744C/T | 5' flanking | 0.21 | 0.20 | 0.59 | 1.10 (0.75–1.61) | 0.62 |
rs2227421 | 9952A/C | 3' UTR | 0.31 | 0.33 | 0.59 | 1.03 (0.74–1.42) | 0.87 |
Gene
|
Haplotype*
|
Controls
%
|
COPD
%
|
Global test P-values†
| |||
---|---|---|---|---|---|---|---|
COPD | Ln (IL-6) | Ln (CRP) | Ln (fibrinogen) | ||||
IL6
| H1 1111111 | 17.8 | 16.1 | 0.003 | 0.80 | 0.08 | 0.73 |
H2 1111112 | 2.4 | 6.2 | |||||
H3 1112111 | 4.8 | 10.2 | |||||
H4 1112112 | 27.8 | 25.0 | |||||
H5 2121211 | 20.1 | 16.1 | |||||
H6 2121221 | 10.4 | 7.7 | |||||
H7 2221211 | 10.1 | 6.3 | |||||
CRP
| H1 111121 | 28.7 | 26.6 | 0.09 | Not tested | 0.0004 | Not tested |
H2 111211 | 30.3 | 24.2 | |||||
H3 121211 | 4.9 | 8.2 | |||||
H4 212111 | 29.7 | 30.4 | |||||
H5 311112 | 5.4 | 7.3 | |||||
FGB
| H1 1111 | 11.9 | 10.3 | 0.28 | Not tested | Not tested | 0.72 |
H2 1112 | 31.2 | 32.8 | |||||
H3 1121 | 21.0 | 19.2 | |||||
H4 1211 | 18.2 | 20.9 | |||||
H5 2111 | 17.4 | 16.2 |
Haplotype-based analysis, COPD and systemic inflammation phenotypes in COPD patients
COPD*
|
Ln(CRP) †
| |||
---|---|---|---|---|
Haplotype | OR (95%CI) | P-value | Coefficient ± SE | P-value |
H1 | 0.85 (0.57–1.27) | 0.42 | -0.33 ± 0.13 | 0.01 |
H2 | 0.86 (0.64–1.16) | 0.43 | -0.13 ± 0.13 | 0.34 |
H3 | 1.64 (0.83–3.27) | 0.16 | -0.58 ± 0.20 | 0.004 |
H4 | REFERENT | REFERENT | ||
H5 | 1.35 (0.69–2.65) | 0.38 | -0.02 ± 0.21 | 0.92 |
Others‡ | 2.91 (0.77–0.98) | 0.12 | 0.66 ± 0.27 | 0.01 |
COPD *
|
Ln (CRP) †
| |||
---|---|---|---|---|
Haplotype | OR (95%CI) | P-value | Coefficient ± SE | P-value |
H1 | 0.92 (0.56–1.51) | 0.75 | 0.005 ± 0.17 | 0.98 |
H2 | 4.82 (1.64–4.18) | 0.004 | -0.94 ± 0.27 | 0.0005 |
H3 | 1.71 (0.85–3.44) | 0.13 | -0.12 ± 0.21 | 0.54 |
H4 | REFERENT | REFERENT | ||
H5 | 1.01 (0.64–1.60) | 0.95 | 0.01 ± 0.17 | 0.93 |
H6 | 0.93 (0.51–1.67) | 0.80 | -0.36 ± 0.22 | 0.10 |
H7 | 0.71 (0.37–1.36) | 0.3 | -0.02 ± 0.24 | 0.94 |
Others‡ | 1.48 (0.79–2.78) | 0.22 | -0.07 ± 0.20 | 0.73 |
Genetic variation and COPD-related phenotypes
Phenotype*
| ||||||
---|---|---|---|---|---|---|
Gene
| BODE index | MRC score | 6MWD, meters | Maximum workload, Watts | BMI, Kg/m2 | FEV1, L |
IL6
| 0.38 | 0.41 | 0.48 | 0.81 | 0.66 | 0.22 |
CRP
| 0.33 | 0.41 | 0.11 | 0.06 | 0.56 | 0.70 |
FGB
| 0.74 | 0.61 | 0.61 | 0.64 | 0.44 | 0.72 |