Table 1. Characteristics of Participants Included in the Analysis of CTX and Tibial pQCT‐Derived Parameters as Mean, SD, Median, 25th (p25), and 75th (p75) Centiles.
| pQCT Variable | Male Mean | SD | p25 | Median | p75 | Female Mean | SD | p25 | Median | p75 |
|---|---|---|---|---|---|---|---|---|---|---|
| Age (years) | 15.43 | 0.24 | 15.29 | 15.38 | 15.51 | 15.45 | 0.25 | 15.30 | 15.41 | 15.55 |
| Height (cm) | 173.91 | 6.97 | 169.30 | 174.40 | 178.70 | 164.62 | 5.82 | 161.10 | 164.40 | 168.30 |
| F‐mass (kg) | 10.04 | 6.78 | 5.72 | 8.14 | 11.95 | 17.65 | 6.58 | 13.04 | 16.44 | 21.46 |
| L‐mass (kg) | 49.54 | 6.19 | 45.53 | 49.46 | 53.82 | 37.01 | 3.66 | 34.68 | 36.75 | 39.46 |
| Weight (kg) | 62.39 | 10.00 | 56.20 | 61.50 | 67.50 | 57.70 | 8.73 | 51.90 | 56.60 | 62.80 |
| CTX (ng/mL) | 1.51 | 0.52 | 1.14 | 1.43 | 1.84 | 0.72 | 0.25 | 0.54 | 0.68 | 0.85 |
| BAc (cm2) | 328.75 | 42.74 | 298.75 | 329.54 | 356.72 | 275.23 | 34.90 | 252.93 | 273.98 | 297.15 |
| BMCc (mg) | 353.53 | 48.86 | 319.97 | 352.04 | 384.76 | 309.78 | 39.53 | 283.68 | 307.32 | 334.96 |
| BMDc (mg/cm3) | 1074.69 | 33.67 | 1055.56 | 1077.66 | 1097.27 | 1125.61 | 22.11 | 1111.37 | 1126.92 | 1140.16 |
| BMDc‐adj‐PC (mg/cm3) | 1084.51 | 35.75 | 1063.39 | 1088.20 | 1108.73 | 1116.55 | 22.74 | 1103.08 | 1117.68 | 1133.01 |
| CT (mm) | 5.62 | 0.62 | 5.21 | 5.63 | 6.02 | 5.20 | 0.54 | 4.82 | 5.21 | 5.56 |
| EC (mm) | 40.96 | 5.48 | 37.26 | 40.73 | 44.10 | 36.71 | 5.03 | 33.49 | 36.15 | 39.47 |
| EC‐adj‐PC (mm) | 38.44 | 3.81 | 36.02 | 38.37 | 40.65 | 38.91 | 3.32 | 36.76 | 38.78 | 40.98 |
| PC (mm) | 76.25 | 5.04 | 73.12 | 76.03 | 79.52 | 69.35 | 4.69 | 66.20 | 68.96 | 72.37 |
| SSI (mm3) | 1159.41 | 219.24 | 1005.68 | 1149.89 | 1301.66 | 918.48 | 172.95 | 801.30 | 895.20 | 1031.73 |
Age = mean age between age at pQCT scan and age when the blood sample was taken; CTX = β‐C‐telopeptides of type I collagen; F‐mass = total body fat mass; L‐mass = total body lean mass; BAc = cortical bone area; BMCC = cortical bone mineral content; BMDC = cortical bone mineral density; PC = periosteal circumference; CT = cortical thickness; EC = endosteal circumference; BMDC‐adj‐PC = cortical bone mineral content adjusted for periosteal circumference; EC‐adj‐PC = endosteal circumference adjusted for periosteal circumference; SSI = strength strain index.
Breakdown of participants according to Tanner stage and gender (male/female) at age 13.5 years: stage 1 (n = 49/30); stage 2 (n = 126/74); stage 3 (n = 135/145); stage 4 (n = 147/260); and stage 5 (n = 30/134).