Descriptive characteristics of the participants in the study by tertiles of cardiorespiratory fitness and knee extension strength in adolescence
| Entire sample | Low CRF | Medium CRF | High CRF | Low strength | Medium strength | High strength | |
| n=8986 | n=3008 | n=2999 | n=2979 | n=3035 | n=2867 | n=3084 | |
| Baseline, conscription | |||||||
| Age, years | 18.3±0.5 | 18.3±0.5 | 18.3±0.5 | 18.3±0.5 | 18.3±0.5 | 18.3±0.5 | 18.3±0.5 |
| Height, cm | 179.7±6.5 | 178.0±6.5 | 179.8±6.2 | 181.4±6.3 | 179.1±6.6 | 179.8±6.4 | 180.3±6.5 |
| Weight, kg | 68.9±9.1 | 64.8±8.9 | 69.5±8.5 | 72.5±8.1 | 64.9±8.1 | 69.1±8.3 | 72.8±9.0 |
| BMI, kg/m2 | 21.3±2.4 | 20.5±2.5 | 21.5±2.3 | 22.0±2.1 | 20.2±2.2 | 21.4±2.2 | 22.4±2.3 |
| Smoking at conscription | |||||||
| No smoker | 6451 (71.8) | 1795 (59.7) | 2144 (71.5) | 2512 (84.3) | 2059 (67.8) | 2044 (71.3) | 2348 (76.1) |
| Ex-smoker | 60 (0.7) | 12 (0.4) | 33 (1.1) | 15 (0.5) | 17 (0.6) | 23 (0.8) | 20 (0.6) |
| Current | 2475 (27.5) | 1201 (39.9) | 822 (27.4) | 452 (15.2) | 959 (31.6) | 800 (27.9) | 716 (23.2) |
| Cardiorespiratory fitness,* W | 259.1±42.6 | 215.9±15.5 | 254.1±10.7 | 307.8±29.1 | 242.4±38.2 | 258.6±39.4 | 276.1±43.0 |
| Extension knee strength,† N | 557.0±114.1 | 509.5±104.1 | 560.5±106.7 | 601.5±112.2 | 438.7±52.7 | 549.8±25.3 | 680.2±74.9 |
| Handgrip strength,‡ N | 613.9±97.2 | 585.1±92.1 | 616.7±94.7 | 640.1±96.8 | 566.8±85.6 | 616.9±87.0 | 657.3±95.9 |
| Elbow flexion strength,§ N | 373.1±81.0 | 344.0±73.3 | 378.1±78.7 | 397.5±81.7 | 327.1±63.4 | 373.7±69.9 | 417.9±80.9 |
| Follow-up, SCAPIS | |||||||
| Follow-up, years | 38.2±3.8 | 39.4±3.6 | 38.2±3.6 | 37.0±3.8 | 38.8±3.7 | 38.3±3.8 | 37.6±3.8 |
| Age, years | 56.5±3.9 | 57.8±3.8 | 56.5±3.8 | 55.3±3.8 | 57.1±3.9 | 56.6±3.9 | 55.9±3.9 |
| BMI, kg/m2 | 27.4±4.0 | 27.1±4.0 | 27.5±4.0 | 27.5±4.0 | 26.6±3.7 | 27.5±4.0 | 28.0±4.1 |
| Educational status | |||||||
| Unfinished primary school | 30 (0.3) | 20 (0.7) | 7 (0.2) | 3 (0.1) | 13 (0.4) | 9 (0.3) | 8 (0.3) |
| Primary school | 781 (8.7) | 398 (13.2) | 262 (8.7) | 121 (4.1) | 295 (9.7) | 249 (8.7) | 237 (7.7) |
| Secondary school | 4511 (50.2) | 1589 (52.8) | 1531 (51.1) | 1391 (46.7) | 1530 (50.4) | 1442 (50.3) | 1539 (49.9) |
| University degree | 3664 (40.8) | 1001 (33.3) | 1199 (40.0) | 1464 (49.1) | 1197 (39.4) | 1167 (40.7) | 1300 (42.2) |
| Coronary stenosis, n=8514 | |||||||
| No | 4039 (47.4) | 1253 (44.3) | 1340 (47.3) | 1446 (50.6) | 1341 (47.0) | 1282 (47.3) | 1416 (48.0) |
| 1%–49% | 3729 (43.8) | 1267 (44.8) | 1249 (44.1) | 1213 (42.5) | 1246 (43.7) | 1174 (43.3) | 1309 (44.4) |
| ≥50% | 746 (8.8) | 307 (10.9) | 241 (8.5) | 198 (6.9) | 265 (9.3) | 255 (9.4) | 226 (7.7) |
| CAC score, Agatston units, n=8642 | |||||||
| 0 | 4231 (49.0) | 1319 (45.8) | 1392 (48.4) | 1520 (52.6) | 1424 (48.6) | 1337 (48.9) | 1470 (49.4) |
| 1–99 | 2999 (34.7) | 1034 (35.9) | 1002 (34.9) | 963 (33.4) | 1008 (34.4) | 976 (35.7) | 1015 (34.1) |
| ≥100 | 1412 (16.3) | 527 (18.3) | 481 (16.7) | 404 (14) | 501 (17.1) | 423 (15.5) | 488 (16.4) |
| Carotid plaques, n=8934 | |||||||
| No | 3690 (41.3) | 1172 (39.2) | 1207 (40.5) | 1311 (44.2) | 1182 (39.2) | 1200 (42.1) | 1308 (42.6) |
| Unilateral | 2725 (30.5) | 863 (28.9) | 940 (31.6) | 922 (31.1) | 949 (31.5) | 845 (29.6) | 931 (30.3) |
| Bilateral | 2519 (28.2) | 953 (31.9) | 831 (27.9) | 735 (24.8) | 882 (29.3) | 808 (28.3) | 829 (27.0) |
Low, medium and high strength refer to knee extension strength.
All data refer to mean±SD or frequency (%).
*Tertile 1: <237 W; Tertile 2: 237–274 W; Tertile 3: ≥275 W.
†Tertile 1: <502 N; Tertile 2: 502–599 N; Tertile 3: ≥600 N.
‡Tertile 1: <570 N; Tertile 2: 570–648 N; Tertile 3: ≥649 N.
§Tertile 1: <331 N; Tertile 2: 331–399 N; Tertile 3: ≥400 N.
BMI, body mass index; CAC, coronary artery calcium; CRF, cardiorespiratory fitness; N, Newtons; SCAPIS, Swedish CArdioPulmonary bioImage Study; W, Watts.