TABLE 1.
Characteristics of cohort participants.
| Variable | All Participants | Boys | Girls | ||||
|---|---|---|---|---|---|---|---|
| Mean (SD) | n | Mean (SD) | n | Mean (SD) | n | P for Sex Difference | |
| Agea (yr) | 9.75 (0.33) | 5566 | 9.7 (0.33) | 2750 | 9.75 (0.33) | 2816 | 0.967 |
| Somatic maturation (puberty) by time to aPHV, n (%) | 22 (0.5) | 4203 | 0 | 2003 | 22 (1) | 2200 | <0.0001 |
| Socioeconomic status based on mother’s occupation | |||||||
| I: Professional (%) | 5.1 | 127 | 5.9 | 75 | 4.2 | 52 | 0.857 |
| II: Managerial and technical (%) | 36.3 | 910 | 35.6 | 453 | 37.0 | 457 | |
| IIIa: Skilled nonmanual (%) | 39.1 | 981 | 38.6 | 491 | 39.6 | 490 | |
| IIIb: Skilled manual (%) | 1.7 | 43 | 1.5 | 19 | 1.9 | 24 | |
| IV: Partly skilled (%) | 14.7 | 370 | 15.8 | 201 | 13.7 | 169 | |
| V: Unskilled (%) | 3.1 | 78 | 2.7 | 34 | 3.6 | 44 | |
| Anthropometry and fat measure | |||||||
| Body height (m) | 1.40 (0.06) | 5510 | 1.40 (0.06) | 2729 | 1.39 (0.06) | 2781 | 0.003 |
| Weighta (kg) | 33.0 (8.6) | 5555 | 32.8 (8.0) | 2743 | 33.40 (9.20) | 2812 | 0.022 |
| Body mass indexa (kg·m−2) | 16.95 (3.32) | 5506 | 16.74 (3.09) | 2727 | 17.22 (3.54) | 2779 | <0.0001 |
| Lean mass (kg) | 24.52 (3.19) | 5304 | 25.49 (2.93) | 2622 | 23.57 (3.14) | 2682 | <0.0001 |
| Lean mass indexed for squared height (kg·m−2) | 12.56 (0.99) | 5255 | 13.00 (0.86) | 2606 | 12.12 (0.91) | 2649 | <0.0001 |
| Total fat massa (kg) | 7.14 (6.06) | 5304 | 5.67 (5.16) | 2622 | 8.41 (6.04) | 2682 | <0.0001 |
| Total fat mass indexed for squared heighta (kg·m−2) | 3.67 (2.94) | 5255 | 2.94 (2.55) | 2606 | 4.37 (2.92) | 2649 | <0.0001 |
| Trunk fat massa (kg) | 2.65 (2.68) | 5304 | 2.04 (2.17) | 2622 | 3.28 (2.81) | 2682 | <0.0001 |
| Trunk fat mass indexed for squared heighta (kg·m−2) | 1.37 (1.34) | 5255 | 1.04 (1.07) | 2606 | 1.70 (1.39) | 2649 | <0.0001 |
| Metabolic profile | |||||||
| HDL (mmol·L−1) | 1.40 (0.31) | 3769 | 1.43 (0.31) | 1902 | 1.37 (0.30) | 1867 | <0.0001 |
| LDL (mmol·L−1) | 2.35 (0.60) | 3769 | 2.26 (0.58) | 1902 | 2.45 (0.61) | 1867 | <0.0001 |
| Triglyceridea (mmol·L−1) | 1.00 (0.60) | 3769 | 0.97 (0.60) | 1902 | 1.04 (0.59) | 1867 | <0.0001 |
| Adiponectina (μg·mL−1) | 12.35 (7.02) | 3767 | 11.88 (6.38) | 1900 | 13.04 (7.37) | 1867 | <0.0001 |
| Fitness measure | |||||||
| CRF (W) | 63.92 (9.07) | 2813 | 67.13 (8.25) | 1179 | 61.61 (8.94) | 1634 | <0.0001 |
| CRF per BM (W·kg BM−1) | 1.92 (0.38) | 2810 | 2.07 (0.38) | 1178 | 1.82 (0.34) | 1632 | <0.0001 |
| CRF per BM0.21 (W·kg BM−0.21) | 31.31 (4.31) | 2810 | 33.04 (3.93) | 1178 | 30.06 (4.14) | 1632 | <0.0001 |
| CRF per LM0.54 (W·kg LM−0.54) | 11.51 (1.46) | 2683 | 11.90 (1.36) | 1122 | 11.21 (1.46) | 1561 | <0.0001 |
| Vascular measure | |||||||
| Pulse rate (bpm) | 79 (11) | 5512 | 77 (10) | 2722 | 81 (11) | 2790 | <0.0001 |
| Systolic blood pressure (mm Hg) | 103 (9) | 5511 | 102 (9) | 2722 | 103 (10) | 2790 | 0.049 |
| Diastolic blood pressure (mm Hg) | 57 (6) | 5512 | 57 (6) | 2722 | 58 (6) | 2790 | 0.002 |
| Brachial artery diameter (mm) | 2.67 (0.30) | 5566 | 2.76 (0.29) | 2750 | 2.59 (0.29) | 2816 | <0.0001 |
| Flow-mediated dilation (%) | 8.07 (3.37) | 5566 | 7.72 (3.25) | 2750 | 8.41 (3.44) | 2816 | <0.0001 |
| Flow-mediated dilation absolute (mm) | 0.21 (0.08) | 5566 | 0.21 (0.09) | 2750 | 0.22 (0.09) | 2816 | 0.029 |
| Carotid-radial PWV (m·s−1) | 7.54 (1.22) | 5566 | 7.63 (1.24) | 2750 | 7.46 (1.20) | 2816 | <0.0001 |
| Distensibility coefficienta (% per mm Hg) | 11.51 (6.91) | 5566 | 11.66 (6.88) | 2750 | 11.35 (6.96) | 2816 | 0.310 |
The values are means (SD) and amedian (interquartile range) except for maturation status and social economic status in percentage. Differences between girls and boys were tested using Student’s t-test for normally distributed continuous variables, Mann–Whitney U test for skewed continuous variables, χ2 test for dichotomous variable, and one-way analysis of variance for multicategorical variable. A two-sided P value <0.05 is considered statistically significant.
aPHV, age at peak height velocity; BM, body mass; CRF, cardiorespiratory fitness; LM, lean mass; PWV, pulse wave velocity; W, watt.