Table 1.
Baseline characteristics of the study cohort (n = 202)
| Demographic Characteristics | |
|---|---|
| Male (%) | 136 (67.3) |
| Ethnicity, n (%) | |
| Native American | 83 (41.1) |
| White | 65 (32.2) |
| Black | 28 (13.9) |
| Hispanic | 23 (11.4) |
| Otherb | 3 (1.5) |
| Age, y | 36.9 ± 10.3 (18, 66) |
| Body composition measurements | |
| Height (cm) | 170.3 ± 8.8 (150.5, 195.0) |
| Body weight (kg) | 89.2 ± 21.9 (47.5, 171.0) |
| BMI (kg/m2) | 30.8 ± 7.7 (17.7, 60.6) |
| Body fat (%) | 30.3 ± 9.4 (7.6, 51.8) |
| FM (kg) | 28.1 ± 13.7 (5.3, 83.3) |
| FFM (kg) | 61.1 ± 12.1 (35.5, 100.6) |
| Energy expenditure measurements during 24-h energy balance | |
| 24EE (kcal/day) | 2150 ± 373 (1350, 3378) |
| Food intake (kcal/day) | 2218 ± 353 (1461, 3353) |
| Energy balance (kcal/day) | 69 ± 147 (–348, 422) |
| Energy balance (%) | 3.7 ± 6.8 (–14.1, 20.0) |
| SMR (kcal/day) | 1662 ± 282 (1060, 2559) |
| 24RQ (ratio) | 0.86 ± 0.04 (0.70, 1.02) |
| EE0 (kcal/15h) | 1422 ± 245 (916, 2192) |
| AFT (kcal/15h) | 384 ± 112 (145, 710) |
| Lipid oxidation (kcal/day) | 707 ± 352 (–385, 1925) |
| Carbohydrate oxidation (kcal/day) | 1031 ± 336 (–194, 2095) |
| Protein oxidation (kcal/day) | 385 ± 104 (149, 1094) |
| SPA (%) | 7.1 ± 4.5 (0.4, 27.5) |
| Urinary catecholamines during energy balance | |
| Norepinephrine (μg/24h) | 34.3 ± 16.9 (6.4, 114.6); 30.5, 23.2-42.7a |
| Epinephrine (μg/24h) | 4.1 ± 2.0 (1.0, 13.2); 3.6, 2.6-5.0a |
| Epinephrine-to-norepinephrine ratio | 0.14 ± 0.08 (0.02, 0.53); 0.12, 0.08-0.17a |
| Urinary metanephrines during energy balance | |
| Normetanephrine (μg/24h) | 276.5 ± 126.7 (65.5, 792.0); 251.1, 191.4-324.2a |
| Metanephrine (μg/24h) | 118.2 ± 47.7 (23.8, 305.1); 113.9, 87.8-141.8a |
| Measurements of glucose metabolism | |
| Fasting glucose (mg/dL) | 94.1 ± 7.7 (77, 118) |
| 2-h glucose during OGTT (mg/dL) | 121.1 ± 29.0 (53, 194) |
| Total glucose AUC during OGTT (μIU/mL × 180 min) | 22 752 ± 3,908 (13 853, 34 800) |
| Fasting insulin (μIU/mL) | 13.9 ± 15.7 (1.2, 147.5); 9.0, 6.0-16.5a |
| 2-h insulin during OGTT (μIU/mL) | 121 ± 29.0 (4.0, 1100.0); 60.0, 32.0-121.5a |
| Total insulin AUC during OGTT (μIU/mL × 180 min) | 16 881 ± 15 221 (2895, 129 885); 12 255, 7673-20 085a |
Values are presented as mean ± SD for continuous variables or number (frequency) for categorical variables with minimum and maximum in parentheses.
Abbreviations: 24EE, 24-hour energy expenditure; 24RQ, 24-hour respiratory quotient, AFT, awake-fed thermogenesis; AUC, area under the curve; BMI, body mass index; EE0, energy expenditure in the inactive, awake state; FFM, fat-free mass; FM, fat mass; OGTT, oral glucose tolerance test; SMR, sleeping metabolic rate; SPA, spontaneous physical activity.
aSkewed values are also expressed as medians with interquartile ranges.
bOther ethnicities comprise 1 individual of Asian and 2 individuals of unknown ethnicity.