Table 2.
Baseline variables by baseline BMI/insulin resistance status
| nBMI | hBMI | pvalue | |||
|---|---|---|---|---|---|
| Variable (SD) | IS | IR | IS | IR | |
| n | 1190 | 212 | 341 | 305 | |
| Age (yrs) | 25.2 (3.5) | 23.9 (4.0) | 25.9 (3.2) | 25.2 (3.8) | <0.01 |
| Gender (% Men) | 495 (42%) | 90 (43%) | 168 (49%) | 139 (46%) | 0.07 |
| Race (%white) | 806 (68%) | 105 (50%) | 190 (56%) | 112 (37%) | <0.01 |
| Weight (kg) | 63.1 (9.5) | 65.4 (8.6) | 80.4 (10.9) | 88.5 (16.3) | <0.01 |
| Waist Girth (cm) | 72 (7) | 74 (6) | 84 (8) | 91 (12) | <0.01 |
| Body Mass Index (kg/m2) | 21.7 (1.9) | 22.4 (1–7) | 27.7 (3.0) | 30.4 (5.0) | <0.01 |
| Smoking (% Never Smoked) | 717 (61%) | 145 (68%) | 206 (61%) | 214 (71%) | 0.01 |
| Caloric Intake (kcal) | 2691 (1400) | 2892 (1457) | 2814 (1589) | 2685 (1367) | 0.17 |
| Alcohol Consumption (ml of alcohol/day) | 12 (18) | 10 (21) | 13 (20) | 11 (24) | 0.31 |
| Level of Education (% more than high school education) | 847 (71%) | 145 (68%) | 239 (70%) | 190 (62%) | 0.03 |
| Study Center | |||||
| Birmingham | 267 (22%) | 42 (20%) | 71 (21%) | 86 (28%) | <0.01 |
| Chicago | 292 (24%) | 49 (23%) | 95 (28%) | 80 (26%) | |
| Minneapolis | 278 (23%) | 39 (18%) | 97 (28%) | 67 (22%) | |
| Oakland | 353 (30%) | 82 (39%) | 78 (23%) | 72 (24%) | |
| Total Activity (exercise units) | 443 (291) | 396 (288) | 467 (335) | 355 (263) | <0.01 |
| Baseline Treadmill Time (seconds) | 648 (157) | 601 (153) | 581 (166) | 501 (158) | <0.01 |
| Mean Arterial Pressure (mmHg) | 81 (8) | 82 (9) | 83 (8) | 85 (9) | <0.01 |
| Glucose (mmol/L) | 4.4 (0.4) | 4.8 (0.4) | 4.5 (0.4) | 4.8 (0.4) | <0.01 |
| Low Density Lipoprotein (mmol/L) | 2.72 (0.75) | 2.87 (0.88) | 2.95 (0.78) | 3.13 (0.78) | <0.01 |
| High Density Lipoprotein (mmol/L) | 1.45 (0.34) | 1.40 (0.31) | 1.32 (0.28) | 1.22 (0.28) | <0.01 |
| Triglycerides (mmol/L) | 0.71 (0.31) | 0.83 (0.46) | 0.82 (0.44) | 1.05 (0.77) | <0.01 |
| HOMA-IR | 1.22 (0.30) | 2.28 (0.58) | 1.38 (0.29) | 2.77 (1.11) | <0.01 |
| Population with Low Fitness at baseline (n, % of BMI/insulin sensitivity category) (<33%tile of sex-specific treadmill time) | 247 (21%) | 69 (33%) | 146 (43%) | 216 (71%) | <0.01 |
| Population with Maintained Fitness (n, % of BMI/insulin sensitivity category) * (increased or decreased ≤20%tile for sex ) *this is change in fitness over 20 years [(Y20–Y0)/Y0] | 250 (21%) | 53 (25%) | 56 (16%) | 63 (21%) | <0.01 |
| Decline in Fitness (seconds: Y20 exercise duration-Y0 exercise duration) | −169 (123) | −154 (123) | −189 (121) | −179 (116) | <0.01 |