Table 1.
Characteristics of All Participants Without Diabetes by Quartile of Midthigh Muscle CSA (mm2), Standardized to Body Weight (kg)
| Quartile 1 (71–127 mm2/kg) | Quartile 2 (127–147 mm2/kg) | Quartile 3 (147–165 mm2/kg) | Quartile 4 (165–228 mm2/kg) | p | |
| Subjects (n) | 147 | 148 | 145 | 147 | |
| OGTT | |||||
| Glucose (mg/dL) | |||||
| Fasting | 90.97 ± 8.76 | 89.76 ± 8.74 | 89.53 ± 8.12 | 88.48 ± 8.27 | <.001 |
| 5 min | 110.32 ± 13.40 | 98.25 ± 12.60 | 96.46 ± 11.01 | 95.38 ± 11.46 | .003 |
| 10 min | 110.19 ± 15.69 | 109.62 ± 16.19 | 106.86 ± 13.59 | 106.47 ± 15.24 | .09 |
| 15 min | 120.06 ± 16.62 | 121.34 ± 19.54 | 118.21 ± 16.65 | 116.15 ± 17.66 | .08 |
| 20 min | 129.07 ± 18.95 | 130.82 ± 21.26 | 127.61 ± 18.25 | 126.02 ± 20.43 | .19 |
| 40 min | 144.48 ± 27.66 | 149.12 ± 28.77 | 146.94 ± 27.78 | 142.29 ± 32.44 | .21 |
| 60 min | 145.76 ± 36.39 | 148.99 ± 37.26 | 147.46 ± 35.73 | 138.18 ± 42.06 | .07 |
| 80 min | 139.22 ± 39.16 | 140.35 ± 38.37 | 136.87 ± 35.20 | 127.13 ± 49.32 | .01 |
| 100 min | 131.93 ± 37.96 | 131.21 ± 37.39 | 127.30 ± 33.52 | 117.52 ± 32.99 | .002 |
| 120 min | 120.53 ± 31.07 | 118.28 ± 31.49 | 116.28 ± 30.07 | 104.61 ± 29.48 | <.001 |
| Insulin (μU/mL) | |||||
| Fasting | 9.66 ± 6.08 | 8.84 ± 5.50 | 8.88 ± 8.39 | 7.87 ± 7.04 | .17 |
| 5 min | 16.99 ± 11.22 | 16.43 ± 11.78 | 14.60 ± 10.36 | 15.08 ± 13.24 | .67 |
| 10 min | 26.19 ± 13.58 | 26.78 ± 17.22 | 25.63 ± 16.29 | 25.24 ± 18.51 | .96 |
| 15 min | 35.57 ± 18.53 | 37.84 ± 27.84 | 33.39 ± 22.34 | 33.93 ± 22.03 | .72 |
| 20 min | 49.70 ± 30.75 | 45.44 ± 30.00 | 45.04 ± 36.11 | 41.88 ± 32.03 | .23 |
| 40 min | 65.76 ± 44.61 | 73.97 ± 49.05 | 70.47 ± 59.56 | 67.21 ± 41.88 | .80 |
| 60 min | 79.20 ± 82.17 | 80.59 ± 54.25 | 82.53 ± 63.37 | 65.80 ± 41.28 | .39 |
| 80 min | 78.55 ± 56.51 | 74.98 ± 49.84 | 76.28 ± 60.39 | 56.09 ± 41.88 | .002 |
| 100 min | 72.83 ± 53.55 | 74.41 ± 54.72 | 68.07 ± 52.81 | 51.83 ± 43.26 | .002 |
| 120 min | 71.74 ± 79.03 | 62.11 ± 49.10 | 59.47 ± 53.35 | 40.90 ± 39.60 | <.001 |
| HOMA-IR units | 2.20 ± 1.57 | 1.98 ± 1.34 | 1.97 ± 1.94 | 1.73 ± 1.61 | .11 |
| Glucose area (mg/min/dL)* | 15,924 ± 3,188 | 16,083 ± 3,118 | 15,758 ± 2,862 | 14,928 ± 3,207 | .007 |
| Insulin area (μU/min/mL)* | 7,887 ± 5,179 | 7,657 ± 4,431 | 7,394 ± 5,165 | 5,916 ± 3,784 | .004 |
| Matsuda index | 4.98 ± 2.85 | 5.27 ± 3.00 | 5.80 ± 3.19 | 7.27 ± 4.82 | <.001 |
| Covariates | |||||
| Age (y) | 73.74 ± 11.23 | 69.66 ± 10.28 | 66.47 ± 11.93 | 59.39 ± 12.22 | <.001 |
| Male (%) | 21.8 | 41.2 | 62.1 | 76.2 | <.001 |
| White (%) | 68.1 | 67.3 | 71.3 | 54.1 | .01 |
| Height (cm) | 165.43 ± 8.32 | 168.44 ± 9.23 | 172.01 ± 9.52 | 172.93 ± 8.87 | <.001 |
| High-intensity activity/walking (kcal/wk) | 1,173.33 ± 1,285.66 | 1,653.56 ± 1,982.01 | 2,192.32 ± 2091.81 | 2,322.12 ± 1843.79 | <.001 |
| Peroneal motor nerve conduction velocity (m/s) | 46.26 ± 5.28 | 47.20 ± 4.48 | 47.27 ± 6.36 | 47.76 ± 5.61 | .20 |
Notes: Data are means ± SD unless otherwise indicated. CSA = cross-sectional area; HOMA-IR = homeostasis model assessment of insulin resistance; OGTT = oral glucose tolerance test.
*
Integrated areas under the curve.