Table 1.
Characteristics of the study population at each study phase
| Phase 3 (1991–1993) | Phase 5 (1997–1999) | Phase 7 (2002–2004) | Phase 9 (2007–2009) | |
|---|---|---|---|---|
| N | 7769 | 6105 | 5749 | 5427 |
| Men (%) | 69.4 (68.3; 70.4) | 70.9 (69.8; 72.1) | 70.5 (69.3; 71.6) | 70.0 (68.8; 71.2) |
| White ethnicity (%) | 90.3 (89.6; 91.0) | 91.8 (91.1; 92.5) | 92.1 (91.3; 92.8) | 91.9 (91.2; 92.6) |
| Age (years) | 50.0 (6.0) | 55.6 (6.0) | 60.8 (5.9) | 65.5 (5.8) |
| Height (cm) | 171.9 (9.5) | 172.1 (9.2) | 171.0 (9.3) | 170.7 (9.3) |
| BMI (kg/m2) | 25.3 (3.7) | 26.1 (3.9) | 26.5 (4.2) | 26.7 (4.4) |
| Waist circumference (cm) | 85.7 (11.5) | 90.5 (11.7) | 93.1 (12.1) | 94.5 (12.0) |
| Current smokers (%) | 13.0 (12.3; 13.8) | 9.5 (8.8; 10.3) | 7.9 (7.2; 8.6) | 5.5 (4.9; 6.1) |
| Moderate to vigorous exercise (hours/week) | 2.0 (1.0; 5.0) | 11.8 (4.8; 20.3) | 11.5 (4.3; 20.0) | – |
| Alcohol intake (units/week) | 6.0 (2.0; 14.0) | 9.0 (3.0; 20.0) | 8.0 (3.0; 17.0) | 7.0 (2.0; 15.0) |
| Diabetes (%) | 3.0 (2.6; 3.4) | 5.6 (5.1; 6.2) | 8.9 (8.1; 9.6) | 12.8 (11.9; 13.7) |
| Medication | ||||
| Antihypertensive treatment (%) | 6.7 (6.2; 7.3) | 11.5 (10.7; 12.3) | 21.2 (20.1; 22.3) | 32.7 (31.4; 34.0) |
| Lipid-lowering treatment (%) | 0.7 (0.5; 0.9) | 2.5 (2.1; 2.9) | 9.2 (8.5; 10.0) | 29.9 (28.7; 31.1) |
| Tricyclic antidepressants (%)a | 1.9 (1.6; 2.2) | 2.7 (2.3; 3.1) | 2.9 (2.5; 3.4) | 3.5 (3.0; 4.0) |
| Diuretics (%) | 6.1 (5.6; 6.7) | 3.0 (2.6; 3.5) | 7.6 (7.0; 8.4) | 10.8 (10.0; 11.7) |
| Beta blockers (%) | 0.6 (0.4; 0.8) | 4.7 (4.2; 5.3) | 8.0 (7.3; 8.7) | 7.4 (6.7; 8.1) |
| Blood measurements | ||||
| Total cholesterol (mmol/l) | 6.5 (1.2) | 5.9 (1.1) | 5.8 (1.0) | 5.3 (1.1) |
| HDL cholesterol (mmol(l) | 1.4 (0.4) | 1.5 (0.4) | 1.6 (0.4) | 1.6 (0.5) |
| LDL cholesterol (mmol/l) | 4.4 (1.0) | 3.9 (0.9) | 3.6 (0.9) | 3.1 (1.0) |
| Triglycerides (mmol/l) | 1.5 (1.1) | 1.4 (0.9) | 1.4 (0.9) | 1.3 (0.7) |
| Systolic blood pressure (mmHg) | 120.6 (13.6) | 123.0 (16.5) | 128 (16.8) | 125.7 (16.1) |
| Diastolic blood pressure (mmHg) | 79.7 (9.4) | 77.5 (10.6) | 74.4 (10.4) | 71.3 (10.2) |
| CRP (mg/dl) | 0.9 (0.4; 1.8) | 1.0 (0.5; 2.0) | 1.2 (0.6; 2.4) | – |
| IL-6 (pg/ml) | 1.4 (1.0; 2.0) | 1.4 (1.0; 2.0) | 1.7 (1.3; 2.4) | – |
| IL-1Ra (pg/ml)b | 251 (195; 329) | 340 (266; 437) | 347 (271; 458) | 347 (273; 450) |
| Adiponectin (µg/ml)b | 8.5 (6.2; 12.1) | 8.5 (6.2; 12.1) | 8.3 (5.9; 11.9) | 8.4 (5.8; 12.9) |
| Heart rate measurements | ||||
| Heart rate from ECG (bpm) | 64.7 (10.7) | 67.3 (11.2) | 67.9 (11.6) | 66.5 (11.5) |
| SDNN (ms) | – | 34.2 (26.0; 44.8) | 33.7(25.4; 44.7) | 29.8 (22.0; 40.1) |
| RMSSD (ms) | – | 20.3 (13.6; 29.4) | 20.5(13.6; 30.2) | 17.5 (11.8; 26.6) |
| Low-frequency power (ms2) | – | 309 (1657; 569) | 284 (157; 524) | 222 (113; 439) |
| High-frequency power (ms2) | – | 128 (615; 251) | 115(56; 236) | 86 (42; 186) |
| LF/HF ratio | – | 2.6 (1.5; 4.1) | 2.6 (1.5; 4.0) | 2.6 (1.6; 4.1) |
| Total power (ms2) | – | 1048 (601;1784) | 1004 (568; 1749) | 779 (423; 1411) |
Data are means (SD), medians (25th; 75th percentiles) or proportions (95% CI)
aAt phase 3, we are not able to separate tricyclic antidepressants from other antidepressants
bSubsample (n = 9459 records)