Table 1.
Characteristics of subjects studied at each TS
| Tanner I
|
Tanner II
|
Tanner III
|
Tanner IV and V
|
|||||
|---|---|---|---|---|---|---|---|---|
| AAs (59) | EAs (71) | AAs (43) | EAs (63) | AAs (35) | EAs (42) | AAs (45) | EAs (37) | |
| Age (yr) | 8.2 ± 0.2 | 9.3 ± 0.1a | 10.4 ± 0.2 | 11.4 ± 0.2a | 11.9 ± 0.2 | 12.8 ± 0.1a | 14.1 ± 0.2 | 14.7 ± 0.2b |
| No. of males (%) | 27 (46) | 29 (41) | 20 (47) | 19 (30) | 11 (31) | 12 (29) | 14 (31) | 18 (49) |
| Wt (kg) | 35.6 ± 1.2 | 35.7 ± 1.4 | 48.6 ± 2.1 | 47.3 ± 1.9 | 60.1 ± 2.5 | 55.9 ± 2.3 | 69.3 ± 2.7 | 65.7 ± 2.8 |
| Wt z score | −0.004 + 0.1 | −0.004 + 0.1 | 0.002 + 0.1 | −0.003 + 0.1 | 0.003 + 0.1 | 0.001 + 0.1 | 0.001 + 0.1 | 0.003 + 0.1 |
| Ht (cm) | 132.6 ± 1.2 | 135.8 ± 1.1b | 146.4 ± 1.2 | 149.7 ± 1.0b | 157.9 ± 1.2 | 159.0 ± 1.1 | 163.9 ± 1.7 | 166.5 ± 2.0 |
| Ht z score | −0.001 + 0.1 | −0.002 + 0.1 | 0.002 + 0.1 | 0.001 + 0.1 | −0.003 + 0.1 | −0.004 + 0.1 | 0.003 + 0.1 | 0.001 + 0.1 |
| BMI | 19.9 ± 0.6 | 18.9 ± 0.5 | 22.2 ± 0.8 | 20.9 ± 0.7 | 23.9 ± 0.8 | 22.0 ± 0.8 | 25.4 ± 0.9 | 23.8 ± 0.9 |
| BMI z score | −0.007 + 0.1 | −0.01 + 0.1 | 0.006 + 0.1 | 0.004 + 0.1 | 0.003 + 0.1 | −0.009 + 0.1 | −0.006 + 0.1 | 0.002 + 0.1 |
| Fat mass (kg) | 10.8 ± 0.9 | 9.7 ± 0.8 | 15.1 ± 6.7 | 14.8 ± 5.9 | 19.6 ± 1.9 | 16.9 ± 1.6 | 22.2 ± 2.1 | 20.7 ± 2.2 |
| Lean mass (kg) | 23.7 + 0.3 | 22.3 + 0.3a | 31.2 + 0.6 | 28.6 + 0.5a | 38.1 + 0.8 | 35.0 + 0.7a | 44.1 + 0.6 | 42.1 + 0.7b |
| Insulin (μU/ml) | 13.54 + 0.86 | 10.46 + 0.76a | 16.51 + 1.01 | 13.09 + 0.89b | 18.04 + 1.57 | 14.63 + 1.39 | 13.22 + 2.07 | 13.52 + 2.18 |
| AIRg (μlU/ml× 10 min) | 1530 ± 155 | 608 ± 35a | 1794 ± 141 | 685 ± 57a | 2317 ± 372 | 592 ± 54a | 1414 ± 140 | 545 ± 47a |
| IGF-I | ||||||||
| Males | 228.6 + 9.4 | 194.5 + 9.2a | 298.6 + 14.1 | 351.8 + 27.7b | 474.9 + 38.3 | 548.6 + 61.6 | 590.8 + 27.5 | 555.6 + 31.1 |
| Females | 266.2 + 12.8 | 216.7 + 8.0a | 407.4 + 27.8 | 403.0 + 17.6 | 580.4 + 25.5 | 577.4 + 16.8 | 551.4 + 17.9 | 571.4 + 21.3 |
| IGFBP-1 | ||||||||
| Males | 93.6 + 9.0 | 124.6 + 12.0b | 34.0 + 4.1 | 49.6 + 5.9b | 22.2 + 5.6 | 41.2 + 4.6b | 18.8 + 2.5 | 25.4 + 5.1 |
| Females | 84.6 + 7.4 | 100.7 + 10.7 | 33.4 + 5.1 | 45.9 + 3.8b | 26.7 + 3.3 | 42.4 + 3.4a | 21.4 + 2.1 | 30.2 + 5.1 |
| IGFBP-3 | ||||||||
| Males | 3584 + 117 | 3827 + 107 | 4100 + 104 | 4509 + 208b | 4384 + 184 | 4958 + 266 | 4685 + 192 | 5130 + 214 |
| Females | 3764 + 112 | 4152 + 106a | 4397 + 135 | 4780 + 128b | 4475 + 157 | 5179 + 139a | 4525 + 134 | 5270 + 273 |
| E2 (pg/ml) | ||||||||
| Males | 4.2 + 0 | 4.3 + 0.1 | 4.2 + 0 | 4.2 + 0 | 4.3 + 42.4 | 6.0 + 1.0 | 8.6 + 1.9 | 8.3 + 2.2 |
| Females | 4.5 + 0.3 | 4.4 + 0.2 | 9.7 + 1.7 | 12.0 + 1.4 | 41.6 + 7.5 | 35.4 + 5.2 | 49.92 + 3.0 | 29.9 + 5.2b |
| T (pg/ml) | ||||||||
| Males | 12.3 + 0.5 | 13.5 + 0.9 | 43.4 + 9.6 | 95.2 + 26.0 | 233.3 + 42.4 | 299.7 + 58.4 | 469.0 + 39.5 | 465.1 + 46.1 |
| Females | 12.4 + 0.3 | 15.8 + 4.0 | 17.1 + 1.6 | 14.4 + 0.9 | 26.9 + 2.9 | 19.0 + 1.2 | 38.2 + 3.01 | 29.0 + 3.0 |
Data are least squares means ± se. Sample size at each TS is in parentheses. Not all children entered the study at TS I (see Subjects and Methods). Data are presented as least squares means because children may have more than one measure at any given TS. Ht, Height; T, total testosterone; Wt, weight.
a
Significantly different by ethnicity, P < 0.01.
b
Significantly different by ethnicity, P < 0.05.