Table 1. Baseline demographic data and results of lung function and laboratory tests for the study population.
| Variables | Nonhyperuricemia, uric acid ≤ 7.0 mg/dL (n = 193) | Hyperuricemia, uric acid > 7.0 mg/dL (n = 47) | P value | ||
|---|---|---|---|---|---|
| Demographics | |||||
| Age, yr | 66.4 ± 7.9 | 66.2 ± 7.0 | 0.856 | ||
| BMI, kg/m2 | 22.8 ± 3.1 | 23.3 ± 2.8 | 0.295 | ||
| St. George's respiratory questionnaire | 29.6 (18.6–42.7) | 25.5 (17.4–41.1) | 0.743 | ||
| Charlson comorbidity score | 0.353 | ||||
| 1 | 154 (79.8) | 35 (74.5) | |||
| 2 | 31 (16.1) | 9 (19.1) | |||
| 3 or more | 8 (4.1) | 3 (6.4) | |||
| Heart failure | 3 (1.6) | 2 (4.3) | 0.553 | ||
| Cerebrovascular disease | 3 (1.6) | 1 (2.1) | 1.000 | ||
| Diabetes | 20 (10.4) | 5 (10.6) | 1.000 | ||
| Hypertension | 59 (30.6) | 23 (48.9) | 0.027 | ||
| Pack-years of smoking | 42.0 (30.0–55.0) | 43.0 (35.9–57.2) | 0.482 | ||
| Current smoking | 64 (33.2) | 15 (31.9) | 1.000 | ||
| Lung function | |||||
| FEV1, % predicted | 52.4 ± 16.4 | 52.3 ± 17.9 | 0.951 | ||
| FVC, % predicted | 84.2 ± 18.7 | 84.8 ± 16.0 | 0.837 | ||
| FEV1/FVC, % | 44.1 ± 10.2 | 43.9 ± 11.8 | 0.891 | ||
| DLCO, % predicted | 77.7 ± 23.7 | 73.3 ± 21.1 | 0.251 | ||
| 6MWD, m | 440.0 (380.0–485.0) | 440.5 (400.0–483.0) | 0.923 | ||
| Laboratory findings | |||||
| Uric acid, mg/dL | 5.5 (4.9–6.2) | 7.6 (7.3–8.4) | < 0.001 | ||
| WBC, 103/µL | 6.8 (5.8–8.3) | 7.1 (6.3–8.7) | 0.157 | ||
| Neutrophil, 103/µL | 3.9 (3.1–4.7) | 4.1 (3.4–5.1) | 0.282 | ||
| Lymphocyte, 103/µL | 2.1 (1.7–2.6) | 2.3 (1.9–2.8) | 0.183 | ||
| Eosinophil, 103/µL | 0.2 (0.1–0.3) | 0.2 (0.1–0.3) | 0.415 | ||
| Neutrophil-lymphocyte Ratio | 1.8 (1.3–2.5) | 1.8 (1.4–2.3) | 0.920 | ||
| Hemoglobin, g/dL | 15.0 (14.1–15.7) | 15.1 (13.8–15.6) | 0.937 | ||
| Platelet, 103/µL | 234.0 (195.0–276.0) | 241.0 (207.0–271.0) | 0.505 | ||
| Protein, g/dL | 7.1 (6.8–7.4) | 7.2 (6.8–7.4) | 0.586 | ||
| Albumin, g/dL | 4.3 (4.1–4.5) | 4.3 (4.0–4.5) | 0.448 | ||
| CrCl, mL/min | 63.8 (53.6–76.0) | 60.0 (50.1–70.5) | 0.082 | ||
Continuous data are presented as mean ± standard deviation or median (interquartile range), categorical data as numbers (%).
BMI = body mass index, mMRC = modified medical research council dyspnea scale, FEV1 = forced expiratory volume in 1 second, FVC = forced vital capacity, DLCO = diffusing capacity of the lung for carbon monoxide, 6MWD = 6-minute walk distance, WBC = white blood cell, CrCl = Creatinine clearance estimate by the Cockcroft-Gault Equation.