Table 3.
Descriptive Characteristics of Participants in the 2 Urine Hormone Classes Identified By the TS3-Centered Growth Mixture Models
| Male Urine Testosterone Classes (centered on age at TS3) | Female Urine Estradiol Classes (centered on age at TS3) | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Class 1 (stable) | Class 2 (unstable) | Class 1 (stable) | Class 2 (unstable) | |||||||
| Characteristic | n | Mean (SD) | n | Mean (SD) | P value | n | Mean (SD) | n | Mean (SD) | P value |
| Age, y | ||||||||||
| At baseline | 103 | 11.8 (1.0) | 60 | 12.0 (1.0) | 0.125 | 98 | 11.6 (0.9) | 21 | 11.8 (1.1) | 0.351 |
| At 3 yearsa | 97 | 14.7 (1.0) | 56 | 15.0 (1.0) | 0.095 | 90 | 14.7 (0.9) | 19 | 14.9 (1.1) | 0.276 |
| Serum hormone concentrationb,c | ||||||||||
| At baseline | 93 | 0.6 (0.1, 4.9) | 51 | 3.4 (0.8, 13.0) | <0.001 | 89 | 97.6 (55.1, 175.5) | 19 | 248.6 (139.1, 287.8) | 0.002 |
| At 3 years | 75 | 9.8 (6.0, 12.6) | 42 | 11.2 (9.3, 13.3) | 0.010 | 54 | 114.2 (77.1, 161.5) | 13 | 186.9 (82.2, 230.2) | 0.102 |
| Age at menarche, y | - | - | - | - | - | 86 | 12.9 (1.5) | 18 | 12.5 (1.1) | 0.334 |
| Tanner stage | ||||||||||
| At baseline | 103 | 2.9 (1.0) | 59 | 2.5 (1.2) | 0.033 | 96 | 2.3 (1.0) | 21 | 2.7 (1.1) | 0.194 |
| At 3 years | 96 | 4.4 (0.9) | 56 | 4.7 (0.6) | 0.079 | 90 | 4.2 (0.8) | 19 | 4.2 (0.8) | 0.786 |
| Maximum TS | 103 | 4.5 (0.7) | 60 | 4.7 (0.6) | 0.047 | 98 | 4.3 (0.8) | 21 | 4.2 (0.7) | 0.925 |
| Linear timing (age at TS3)d | 103 | 11.9 (1.1) | 60 | 12.7 (1.0) | <0.001 | 98 | 12.3 (1.1) | 21 | 12.4 (1.1) | 0.802 |
| Linear tempo (average ∆TS/y)d | 103 | 0.5 (0.3) | 60 | 0.7 (0.4) | 0.004 | 98 | 0.7 (0.4) | 21 | 0.5 (0.4) | 0.133 |
| Logistic timing (age at TS3)e | 103 | 12.3 (0.8) | 60 | 12.6 (0.7) | 0.004 | 98 | 12.6 (0.8) | 21 | 12.5 (0.9) | 0.646 |
| Logistic tempo (slope at TS3; TS/y)e | 103 | 1.0 (0.4) | 60 | 1.2 (0.4) | 0.002 | 98 | 0.9 (0.2) | 21 | 0.8 (0.2) | 0.188 |
| Height, cm | ||||||||||
| At baseline | 103 | 151.1 (10.2) | 60 | 154.4 (10.0) | 0.048 | 98 | 150.1 (8.9) | 21 | 153.7 (8.0) | 0.093 |
| At 3 years | 97 | 170.2 (9.6) | 55 | 173.7 (6.8) | 0.992 | 89 | 163.9 (6.6) | 17 | 163.6 (4.8) | 0.856 |
| ∆ over 3 years | 97 | 19.4 (5.0) | 55 | 20.0 (5.5) | 0.494 | 89 | 14.0 (5.5) | 17 | 10.3 (4.5) | 0.015 |
| Maximum ∆ height, cm/y | 103 | 8.8 (1.9) | 60 | 9.2 (2.2) | 0.176 | 98 | 6.7 (2.6) | 21 | 5.7 (2.5) | 0.114 |
| Age at maximum ∆ height, y | 66 | 13.7 (1.0) | 44 | 13.1 (0.9) | 0.005 | 49 | 12.2 (0.8) | 6 | 11.5 (0.6) | 0.048 |
| Weight (kg) | ||||||||||
| At baseline | 103 | 44.0 (12.7) | 60 | 46.4 (11.3) | 0.243 | 98 | 44.8 (12.1) | 21 | 48.5 (12.4) | 0.218 |
| At 3 years | 97 | 62.0 (16.6) | 56 | 66.3 (13.8) | 0.107 | 89 | 60.3 (13.1) | 17 | 58.5 (11.4) | 0.578 |
| ∆ over 3 years | 97 | 18.3 (6.3) | 56 | 20.0 (7.2) | 0.134 | 89 | 16.1 (7.1) | 17 | 11.2 (5.9) | 0.012 |
P values below 0.05 are shown in bold text. Abbreviations: ∆, change; SD, standard deviation; TS, Tanner stage.
aReduced sample size for measures at 3 years are due to study attrition and adolescent refusal to provide a blood sample.
bData presented as median (interquartile range).
cSerum testosterone in males expressed in nmol/L; serum estradiol in females expressed in pmol/L.
dTiming and tempo derived from linear models of Tanner stage change (Beltz et al. Dev Psychol 2014;50:2715–26).
eTiming and tempo derived from logistic models of Tanner stage change (Marceau et al. Dev Psychol 2011;47:1389–409).