Table 1.
Baseline characteristics of the study population
| Characteristics | Total participants (N=175)* |
|---|---|
| Sex, male | 171 (97.7) |
| Age, years | 66.4±6.8 |
| Height, cm | 165.4±6.2 |
| BMI, kg/m2 | 22.9±3.4 |
| Smoking status | |
| Current | 45 (25.7) |
| Former | 130 (74.3) |
| Pack-years | 45.6±23.1 |
| Underlying diseases | |
| Coronary vascular disease | 18 (10.3) |
| Cerebrovascular disease | 7 (4.0) |
| Hypertension | 55 (31.4) |
| Diabetes mellitus | 19 (10.9) |
| Chronic kidney disease | 3 (1.7) |
| Liver disease | 7 (4.0) |
| Asthma | 50 (28.6) |
| Malignancy | 6 (5.1) |
| FEV1, L | 1.51±0.51 |
| FEV1, % predicted | 57.5±18.0 |
| FVC, L | 3.16±0.84 |
| FVC, % predicted | 84.1±20.9 |
| FEV1/FVC, % | 48.0±10.6 |
| GOLD classification | |
| I | 12 (6.9) |
| II | 87 (49.7) |
| III | 64 (36.6) |
| IV | 12 (6.9) |
| Measured with emphysema index, % (N=131) | 21.9±16.5 |
| Measured with 6MW distance, meters (m) (N=129) | 438.7±77.5 |
| Plasma 25-hydroxyvitamin D3 level, ng/mL | 17.5±9.5 |
| VDBP variants (N=350)# | |
| GC1F | 155 (44.3) |
| GC1S | 83 (23.7) |
| GC2 | 112 (32.0) |
| Genotypes (N=175) | |
| 1F-1F | 35 (20.0) |
| 1F-1S | 37 (21.1) |
| 1F-2 | 48 (27.4) |
| 1S-1S | 8 (4.6) |
| 1S-2 | 30 (17.1) |
| 2-2 | 17 (9.7) |
Note:
*
Data are presented as the number of patients (percentage) or mean ± standard deviation.
#
Number of total variants; because there are two variants in each individual, double the number (350) of 175 is included in the analysis.
Abbreviations: BMI, body mass index; FEV1, forced expiratory volume in 1 second; FVC, forced vital capacity; GOLD, Global Initiative for Chronic Obstructive Lung Disease; 6MW, 6-minute walking; VDBP, vitamin D-binding protein.