Table 1.
Baseline Demographic and Health Characteristics of Participants in the CARDIA Study
| Variables | Total N = 5,114 |
White women n = 1,307 |
Black women n = 1,480 |
White men n = 1,170 |
Black men n = 1,157 |
p-value |
|---|---|---|---|---|---|---|
| Baseline demographic characteristics | ||||||
| Age, years, median (IQR) | 25.0 (22.0‒28.0) | 26.0 (23.0‒28.0) | 24.0 (21.0‒28.0) | 26.0 (23.0‒28.0) | 24.0 (21.0‒28.0) | <0.001 |
| Highest grade of school completed, median (IQR) | 13.0 (12.0‒16.0) | 15.0 (12.0‒16.0) | 13.0 (12.0‒14.0) | 15.0 (12.0‒16.0) | 12.0 (12.0‒14.0) | <0.001 |
| Family history of hypertension, n (%) | 2,670 (52.2) | 619 (47.4) | 889 (60.1) | 522 (44.6) | 640 (55.3) | <0.001 |
| Family history of cardiovascular disease, n (%) | 1,022 (20.0) | 250 (19.1) | 310 (20.9) | 227 (19.4) | 235 (20.3) | 0.62 |
| BMI, median (IQR) | 23.4 (21.2‒26.4) | 22.0 (20.3‒24.6) | 24.2 (21.2‒28.9) | 23.7 (21.9‒26.0) | 23.7 (21.7‒26.4) | <0.001 |
| <25 kg/m2, n (%) | 3,328 (65.3) | 1,012 (77.7) | 823 (55.8) | 761 (65.2) | 732 (63.5) | |
| 25‒30 kg/m2, n (%) | 1,170 (23.0) | 195 (15.0) | 337 (22.8) | 334 (28.6) | 304 (26.4) | |
| >30 kg/m2, n (%) | 599 (11.8) | 95 (7.3) | 315 (21.4) | 72 (6.2) | 117 (10.1) | |
| Smoking status, n (%) | <0.001 | |||||
| Never | 2,856 (56.2) | 685 (52.7) | 885 (60.1) | 670 (57.8) | 616 (53.8) | |
| Former | 676 (13.3) | 261 (20.1) | 127 (8.6) | 182 (15.7) | 106 (9.3) | |
| Current | 1,546 (30.4) | 355 (27.3) | 461 (31.3) | 307 (26.5) | 423 (36.9) | |
| Alcohol (mL of alcohol consumed per day), median (IQR) | 5.4 (0.9‒15.5) | 4.8 (0.9‒12.1) | 1.8 (0.0‒6.9) | 11.1 (3.7‒23.2) | 10.2 (2.0‒25.2) | <0.001 |
| Total physical activity score at enrollment (EU), median (IQR) | 360.0 (197.0‒578.0) | 351.0 (207.0‒543.0) | 228.0 (103.0‒396.0) | 462.0 (288.0‒672.0) | 472.0 (271.0‒723.0) | <0.001 |
| Total physical activity score at age 18 (EU), median (IQR) | 373.7 (251.9‒536.0) | 340.0 (243.0‒472.2) | 238.5 (163.8‒337.4) | 480.7 (352.3‒613.9) | 516.0 (384.3‒673.9) | <0.001 |
| Annual reduction in total physical activity score (EU), median (IQR) | 2.3 (0.6‒4.5) | 1.3 (‒0.3‒3.1) | 1.3 (0.2‒2.8) | 2.5 (1.1‒4.2) | 5.1 (3.7‒7.3) | <0.001 |
| Expected total physical activity score always >300 EUs, n (%) | 1,658 (55.8) | 545 (53.9) | 230 (27.1) | 500 (77.5) | 383 (82.5) | <0.001 |
| Expected total physical activity score always >600 EUs, n (%) | 347 (11.7) | 63 (6.2) | 25 (3.0) | 131 (20.3) | 128 (27.6) | <0.001 |
| Hypertension, n (%) | 732 (14.3) | 86 (6.6) | 157 (10.6) | 240 (20.5) | 249 (21.5) | |
| Systolic blood pressure, median (IQR) | 110.0 (103.0‒118.0) | 104.0 (99.0‒110.0) | 107.0 (101.0‒114.0) | 114.0 (107.0‒121.0) | 115.0 (109.0‒122.0) | <0.001 |
| Diastolic blood pressure, median (IQR) | 68.0 (62.0‒75.0) | 66.0 (61.0‒71.0) | 67.0 (62.0‒73.0) | 71.0 (65.0‒77.0) | 71.0 (64.0‒77.0) | <0.001 |
| Diabetes, n (%) | 32 (0.6) | 7 (0.5) | 14 (1.0) | 6 (0.5) | 5 (0.4) | 0.29 |
| LDL cholesterol, median (IQR) | 106.0 (87.0‒127.0) | 102.0 (85.0‒123.0) | 107.0 (88.0‒129.0) | 109.0 (89.0‒129.0) | 106.0 (85.0‒127.0) | <0.001 |
| HDL cholesterol, median (IQR) | 52.0 (44.0‒61.0) | 55.0 (47.0‒64.0) | 54.0 (46.0‒64.0) | 45.0 (40.0‒53.0) | 52.0 (44.0‒61.0) | <0.001 |
| Triglycerides, median (IQR) | 62.0 (45.0‒84.0) | 62.0 (45.0‒81.5) | 56.0 (42.0‒75.0) | 72.0 (52.0‒103.0) | 60.0 (45.0‒82.0) | <0.001 |
Note: Boldface indicates statistical significance (p<0.05).
A total physical activity score of 300 EUs approximates the HHS recommendations of approximately 150 minutes of moderate-intensity activity per week.
CARDIA, Coronary Artery Risk Development in Young Adults Study; EU, exercise unit; HDL, high-density lipoprotein; LDL, low-density lipoprotein.