Characteristic* | Quintiles of FEV1 measure† | Total | ||||
Q1 (lowest) | Q2 | Q3 | Q4 | Q5 (highest) | ||
No. of participants | 2941 | 2942 | 2942 | 2942 | 2941 | 14 708 |
Age, years | 56.6 (5.5) | 54.9 (5.6) | 53.8 (5.6) | 53.6 (5.8) | 52.5 (5.4) | 54.3 (5.8) |
Males (%) | 440 (15.0) | 563 (19.1) | 958 (32.6) | 1923 (65.4) | 2825 (96.1) | 6709 (45.6) |
White (%) | 1709 (58.1) | 2022 (68.7) | 2253 (76.6) | 2378 (80.8) | 2636 (89.6) | 10 998 (74.8) |
Education (%) | ||||||
Less than high school | 1096 (37.3) | 880 (27.5) | 621 (21.1) | 582 (19.8) | 360 (12.3) | 3467 (23.6) |
High school | 1157 (39.4) | 1277 (43.5) | 1287 (43.8) | 1164 (39.6) | 1131 (38.5) | 6016 (41.0) |
College | 684 (23.3) | 853 (29.0) | 1029 (35.0) | 1193 (40.6) | 1446 (49.2) | 5205 (35.4) |
Sitting height, cm | 84.6 (5.6) | 86.2 (4.6) | 88.0 (4. 6) | 90.4 (4.2) | 93.5 (4.2) | 88.6 (5.6) |
Body mass index, kg/m2 | 28.7 (6.8) | 27.9 (5.8) | 27.3 (5.4) | 27.2 (4.7) | 27.3 (3.8) | 27.7 (5.4) |
Systolic blood pressure, mm Hg | 126.5 (20.9) | 121.9 (19.7) | 119.8 (18.3) | 119.8 (18.3) | 118.3 (15.5) | 121.2 (18.9) |
Diastolic blood pressure, mm Hg | 73.6 (12.2) | 72.8 (11.4) | 73.2 (11.0) | 74.0 (11.4) | 74.4 (10.3) | 73.6 (11.3) |
Smoking status (%) | ||||||
Never | 1138 (18.8) | 1357 (22.5) | 1312 (21.7) | 1160 (19.2) | 1072 (17.8) | 6039 (41.1) |
Former | 647 (13.5) | 745 (15.6) | 910 (19.0) | 1118 (23.4) | 1367 (28.6) | 4787 (32.6) |
Current | 1156 (29.8) | 840 (21.6) | 720 (18.6) | 664 (17.1) | 502 (12.9) | 3882 (26.4) |
Pack-years | 33.1 (11.2) | 29.4 (12.0) | 27.2 (12.3) | 26.7 (12.1) | 22.7 (11.3) | 27.8 (12.3) |
Clinical history (%) | ||||||
Hypertension | 1425 (48.5) | 1107 (37.6) | 990 (33.7) | 907 (30.8) | 705 (24.0) | 5134 (34.9) |
Diabetes mellitus | 560 (19.0) | 379 (12.9) | 297 (10.1) | 301 (10.2) | 236 (8.0) | 1773 (12.1) |
Coronary heart disease | 160 (5.4) | 119 (4.0) | 143 (4.9) | 172 (5.9) | 129 (4.4) | 723 (4.9) |
Chronic heart failure | 312 (10.6) | 170 (5.8) | 118 (4.0) | 62 (2.1) | 47 (1.6) | 709 (4.8) |
Total cholesterol, mg/dL | 221.0 (45.5) | 218.8 (43.3) | 214.9 (40.5) | 212.0 (40.3) | 209.3 (39.0) | 215.2 (42.0) |
LDL-cholestrol, mg/dL | 140.1 (42.6) | 138.9 (40.3) | 136.0 (38.3) | 136.6 (38.2) | 138.2 (36.4) | 137.9 (39.2) |
HDL-cholestrol, mg/dL | 53.9 (17.4) | 54.3 (17.2) | 54.2 (17.8) | 49.6 (17.1) | 44.8 (13.3) | 51.3 (17.0) |
Triglycerides, mg/dL | 137.0 (91.0) | 132.5 (92.4) | 126.4 (86.9) | 132.0 (92.5) | 135.9 (91.4) | 132.7 (90.9) |
Fasting blood glucose, mg/dL | 114.8 (55.6) | 108.8 (44.1) | 106.0 (39.8) | 106.8 (35.2) | 105.0 (27.5) | 108.3 (41.6) |
Markers of inflammation | ||||||
White cell count, ×103/mm3 | 6.4 (2.4) | 6.1 (2.1) | 5.9 (2.0) | 6.0 (2.0) | 5.9 (2.1) | 6.1 (2.1) |
Fibrinogen, mg/dL | 326.4 (80.9) | 308.4 (67.4) | 299.4 (65.0) | 294.9 (64.6) | 282.6 (58.0) | 302.2 (69.1) |
Albumin, g/dL | 3.8 (0.3) | 3.8 (0.3) | 3.9 (0.3) | 3.9 (0.3) | 4.0 (0.2) | 3.9 (0.3) |
Von Willebrand’s factor, % | 128.8 (56.4) | 121.7 (50.2) | 115.9 (47.5) | 113.7 (44.8) | 109.9 (43.5) | 118.0 (49.1) |
Electrographic findings | ||||||
Resting hear rate, bpm | 68.9 (11.1) | 67.2 (10.3) | 66.2 (9.9) | 65.3 (9.8) | 63.9 (9.8) | 66.3 (10.3) |
QTc, ms | 421.6 (22.0) | 419.3 (23.2) | 417.2 (18.8) | 413.7 (17.4) | 410.0 (17.7) | 416.4 (20.4) |
Left ventricular hypertrophy (%) | 114 (3.9) | 83 (2.8) | 57 (1.9) | 38 (1.3) | 27 (0.9) | 319 (2.2) |
Spirometry | ||||||
FEV1, L | 1.8 (0.3) | 2.4 (0.1) | 2.7 (0.1) | 3.2 (0.2) | 4.0 (0.4) | 2.8 (0.8) |
FVC, L | 2.7 (0.5) | 3.2 (0.4) | 3.7 (0.4) | 4.2 (0.4) | 5.2 (0.6) | 3.8 (1.0) |
FEV1/FVC | 61.9 (7.5) | 71.7 (1.4) | 75.5 (1.0) | 78.7 (0.9) | 83.5 (2.9) | 74.3 (8.2) |
FEV1/FVC ratio <70% (%) | 1287 (43.8) | 642 (21.8) | 554 (18.8) | 514 (17.5) | 341 (11.6) | 3338 (22.7) |
FEV1%, predicted | 75.1 (17.7) | 91.7 (13.8) | 97.0 (14.7) | 97.8 (14.0) | 103.9 (10.4) | 93.1 (17.3) |
FVC%, predicted | 86.9 (15.0) | 99.3 (13.2) | 103.7 (14.0) | 103.9 (14.0) | 108.1 (11.0) | 100.4 (11.0) |
Self-reported diagnosis (%) | ||||||
Bronchitis‡ | 530 (18.0) | 309 (10.5) | 219 (7.4) | 178 (6.1) | 123 (4.2) | 1359 (9.2) |
Asthma | 371 (12.6) | 171 (5.8) | 151 (5.1) | 151 (5.1) | 127 (4.3) | 971 (6.6) |
Emphysema | 156 (5.3) | 37 (1.3) | 20 (0.7) | 32 (1.1) | 25 (0.9) | 270 (1.8) |
Medications (%) | ||||||
Anticholinergics | 15 (0.5) | 0 (0) | 1 (0) | 1 (0) | 0 (0) | 17 (0.1) |
Beta-agonists | 148 (5.0) | 33 (1.1) | 11 (0.4) | 13 (0.4) | 13 (0.4) | 218 (1.5) |
Xanthines | 158 (5.4) | 40 (1.4) | 12 (0.4) | 20 (0.7) | 14 (0.5) | 244 (1.7) |
Inhaled corticosteroids | 24 (0.8) | 20 (0.7) | 8 (0.3) | 11 (0.4) | 11 (0.4) | 74 (0.5) |
*Expressed as mean and SD or percentages.
†FEV1 measured using standardised spirometry at study baseline.
‡Chronic bronchitis was defined as productive cough for at least 3 months in two contiguous years.
HDL, high-density lipoprotein; LDL, low-density lipoprotein.