Table 2.
Sample Characteristics by Sedentary Index Quintiles, the Coronary Artery Risk Development in Young Adults Study, 2010–2011
| Characteristic | Quintiles of Sedentary Time, mean (SD) | ||||||
|---|---|---|---|---|---|---|---|
| Total (n = 3,211) | 1 (n = 635) |
2 (n = 649) |
3 (n = 641) |
4 (n = 638) |
5 (n = 648) |
P Valuea | |
| Age, years | 50.1 (3.6) | 50.4 (3.5) | 50.2 (3.4) | 50.4 (3.6) | 50.1 (3.7) | 49.6 (3.7) | <0.001 |
| Female sexb | 56.2 | 55.1 | 55.8 | 57.7 | 55.8 | 56.5 | 0.908 |
| White raceb | 53.6 | 73.4 | 69.2 | 56.0 | 42.3 | 27.3 | <0.001 |
| Years of education | 15.1 (2.7) | 15.7 (2.6) | 15.5 (2.7) | 15.1 (2.7) | 15.0 (2.6) | 14.2 (2.6) | <0.001 |
| Unemployedb | 15.1 | 10.1 | 9.2 | 15.8 | 19.1 | 21.5 | <0.001 |
| Had health insuranceb | 87.2 | 91.3 | 90.5 | 88.8 | 85.0 | 80.4 | <0.001 |
| Ever smokerb | 37.8 | 32.8 | 34.8 | 39.8 | 38.1 | 43.5 | <0.001 |
| Alcohol consumption, mg/day | 11.6 (23.6) | 12.7 (25.8) | 11.5 (18.9) | 12.2 (22.0) | 12.4 (31.5) | 9.4 (17.3) | 0.056 |
| Total physical activity, exercise units | 340.9 (276.6) | 400.1 (286.1) | 369.1 (281.6) | 311.2 (251.94) | 332.3 (279.6) | 292.7 (270.0) | <0.001 |
| Fast food consumption per week | 2.1 (3.1) | 1.7 (3.1) | 1.7 (2.5) | 2.0 (2.5) | 2.4 (3.2) | 2.9 (3.6) | <0.001 |
| Sugar-sweetened beverage consumption per week | 3.9 (7.9) | 2.6 (6.5) | 2.7 (6.2) | 3.6 (6.9) | 4.4 (7.4) | 6.5 (10.8) | <0.001 |
| Depressive symptoms | 9.3 (7.7) | 8.3 (7.5) | 8.2 (6.3) | 9.6 (8.1) | 9.6 (7.4) | 10.9 (8.7) | <0.001 |
| Body mass indexc | 30.2 (7.2) | 27.6 (6.4) | 29.0 (6.5) | 30.5 (7.0) | 31.5 (7.3) | 32.2 (7.6) | <0.001 |
| Time spent on sedentary tasks, hours/day | |||||||
| Total | 7.0 (4.0) | 3.0 (0.8) | 4.7 (0.4) | 6.1 (0.5) | 8.1 (0.7) | 13.2 (4.0) | <0.001 |
| Watching television | 2.2 (1.5) | 0.9 (0.7) | 1.6 (0.9) | 2.1 (1.1) | 2.7 (1.4) | 3.6 (1.5) | <0.001 |
| Computer work | 1.1 (1.3) | 0.4 (0.4) | 0.7 (0.5) | 0.9 (0.8) | 1.3 (1.2) | 2.3 (1.8) | <0.001 |
| Paperwork | 0.7 (0.8) | 0.3 (0.2) | 0.4 (0.3) | 0.6 (0.5) | 0.8 (0.8) | 1.4 (1.3) | <0.001 |
| Reading | 1.1 (1.1) | 0.5 (0.4) | 0.7 (0.6) | 1.0 (0.8) | 1.2 (1.0) | 2.0 (1.5) | <0.001 |
| Talking on the telephone | 0.7 (1.0) | 0.3 (0.3) | 0.4 (0.3) | 0.5 (0.5) | 0.8 (0.7) | 1.7 (1.5) | <0.001 |
| Sitting in a car | 1.2 (1.1) | 0.6 (0.4) | 0.9 (0.6) | 1.0 (0.7) | 1.3 (1.1) | 2.2 (1.6) | <0.001 |
| Cardiometabolic risk factors | |||||||
| Waist circumference, cm | 94.4 (15.8) | 88.9 (14.8) | 92.3 (15.0) | 95.3 (15.9) | 96.8 (15.6) | 98.7 (15.9) | <0.001 |
| Systolic blood pressure, mmHg | 118.7 (15.4) | 116.4 (15.1) | 116.8 (15.0) | 119.2 (15.7) | 119.0 (15.0) | 121.9 (15.8) | <0.001 |
| Diastolic blood pressure, mmHg | 73.9 (10.9) | 71.2 (10.6) | 72.4 (10.6) | 74.6 (10.7) | 74.8 (10.5) | 76.7 (10.9) | <0.001 |
| Glucose, mg/dL | 99.5 (28.7) | 96.2 (24.3) | 97.1 (21.0) | 99.7 (33.0) | 100.5 (27.6) | 103.7 (34.5) | <0.001 |
| Insulin, uU/mL | 11.2 (9.6) | 8.4 (6.9) | 10.0 (7.4) | 11.6 (8.8) | 12.3 (8.7) | 13.9 (13.6) | <0.001 |
| Triglycerides, mg/dL | 113.7 (81.3) | 104.0 (82.3) | 113.4 (79.9) | 119.5 (87.3) | 114.3 (76.8) | 117.0 (79.2) | 0.009 |
| HDL-C, mg/dL | 58.0 (18.0) | 61.7 (19.3) | 58.8 (18.0) | 57.5 (17.6) | 56.4 (16.5) | 55.6 (17.8) | <0.001 |
| Cardiometabolic risk scored | −0.04 (0.7) | −0.3 (0.6) | −0.1 (0.6) | 0.0 (0.7) | 0.0 (0.6) | 0.2 (0.6) | <0.001 |
Abbreviations: HDL-C, high-density lipoprotein cholesterol; SD, standard deviation.
aP value for linear trend over sedentary quintiles was tested using linear regression (continuous variables) or χ2 test of independence (categorical variables).
b Values are expressed as column percentages.
c Weight (kg)/height (m)2.
d Cardiometabolic risk score was calculated by standardizing and summing waist circumference, average blood pressure ([systolic + diastolic]/2), log glucose, log insulin, log triglycerides, and negative log HDL-C and then dividing by 6 to create a z score.