Age | Sex | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
10–12 years | 13–15 years | Boys | Girls | |||||||||
M | SD | M | SD | F | η2 | M | SD | M | SD | F | η2 | |
Systolic blood pressure (mm Hg) | 108.5 | 11.0 | 111.1 | 11.6 | 8.7** | 0.001 | 109.1 | 12.1 | 109.9 | 10.6 | 0.8 | – |
Diastolic blood pressure (mm Hg) | 65.9 | 7.8 | 67.5 | 8.4 | 6.4** | 0.010 | 65.8 | 8.2 | 67.2 | 8.0 | 4.5* | 0.007 |
Skinfolds (mm) | 11.4 | 6.2 | 10.6 | 6.1 | 2.8 | – | 8.9 | 5.2 | 13.0 | 6.3 | 81.1*** | 0.111 |
Total cholesterol (mmol/L) | 3.6 | 0.7 | 3.5 | 0.6 | 2.4 | – | 3.5 | 0.6 | 3.6 | 0.7 | 3.8 | – |
HDL cholesterol (mmol/L) | 1.4 | 0.3 | 1.4 | 0.3 | 2.2 | – | 1.4 | 0.4 | 1.4 | 0.3 | 0.0 | – |
LDL cholesterol (mmol/L) | 1.8 | 0.5 | 1.8 | 0.6 | 0.9 | – | 1.7 | 0.5 | 1.8 | 0.6 | 3.0 | – |
Triglycerides (mmol/L) | 0.8 | 0.3 | 0.8 | 0.3 | 0.0 | – | 0.8 | 0.3 | 0.8 | 0.3 | 7.2** | 0.011 |
HbA1c (%) | 5.5 | 0.2 | 5.5 | 0.3 | 2.5 | – | 5.5 | 0.2 | 5.5 | 0.2 | 8.3** | 0.013 |
Clustered risk index | 0.0 | 2.8 | 0.0 | 3.1 | 0.2 | – | −0.5 | 2.9 | 0.4 | 2.8 | 16.4*** | 0.025 |
Sedentary activity | 670.5 | 77.8 | 652.3 | 93.4 | 7.2** | 0.011 | 643.4 | 88.5 | 680.4 | 77.3 | 32.4*** | 0.048 |
Light physical activity (min/day) | 266.8 | 46.3 | 254.2 | 55.4 | 9.9** | 0.015 | 269.8 | 47.8 | 255.1 | 51.6 | 14.0*** | 0.021 |
Moderate physical activity (min/day) | 48.5 | 19.2 | 54.2 | 19.4 | 13.6*** | 0.021 | 60.5 | 18.7 | 42.5 | 16.0 | 174.9*** | 0.213 |
Vigorous physical activity (min/day) | 20.8 | 14.9 | 23.3 | 16.5 | 3.9* | 0.006 | 30.5 | 17.5 | 14.4 | 8.3 | 235.1*** | 0.266 |
Moderate-to-vigorous physical activity (min/day) | 69.3 | 32.3 | 77.5 | 33.4 | 9.7** | 0.015 | 91.0 | 33.5 | 56.8 | 22.8 | 236.2*** | 0.266 |
Cardiorespiratory fitness (laps in 20 m shuttle run test) | 33.3 | 18.7 | 41.1 | 21.7 | 23.2*** | 0.036 | 48.0 | 20.2 | 26.4 | 14.0 | 250.7*** | 0.284 |
Socioeconomic status† | Ethnicity‡ | |||||||||||
Lower (0–7) | Higher (8–9) | Black African | Coloured | |||||||||
M | SD | M | SD | F | η2 | M | SD | M | SD | F | η2 | |
Systolic blood pressure (mm Hg) | 109.7 | 11.3 | 109.3 | 11.4 | 0.2 | – | 108.8 | 11.6 | 110.3 | 10.8 | 2.7 | – |
Diastolic blood pressure (mm Hg) | 66.4 | 8.0 | 66.6 | 8.2 | 0.1 | – | 65.4 | 8.4 | 68.4 | 7.4 | 20.7*** | 0.033 |
Skinfolds (mm) | 10.0 | 5.3 | 11.7 | 6.6 | 9.1** | 0.015 | 11.9 | 6.5 | 10.0 | 5.7 | 13.7 | 0.022 |
Total cholesterol (mmol/L) | 3.6 | 0.6 | 3.5 | 0.7 | 1.5 | – | 3.5 | 0.6 | 3.7 | 0.7 | 12.7*** | 0.020 |
HDL cholesterol (mmol/L) | 1.4 | 0.3 | 1.4 | 0.3 | 1.1 | – | 1.4 | 0.3 | 1.4 | 0.3 | 2.6 | – |
LDL cholesterol (mmol/L) | 1.8 | 0.5 | 1.8 | 0.6 | 2.7 | – | 1.7 | 0.5 | 1.8 | 0.6 | 4.8* | 0.008 |
Triglycerides (mmol/L) | 0.8 | 0.3 | 0.8 | 0.3 | 2.2 | – | 0.8 | 0.3 | 0.9 | 0.3 | 15.6** | 0.025 |
HbA1c (%) | 5.5 | 0.2 | 5.5 | 0.2 | 0.3 | – | 5.5 | 0.2 | 5.5 | 0.2 | 3.0 | – |
Clustered risk index | 0.0 | 2.8 | −0.2 | 3.0 | 0.1 | – | −0.1 | 3.0 | 0.1 | 2.9 | 0.6 | – |
Sedentary activity | 662.3 | 84.4 | 665.5 | 83.4 | 0.2 | – | 676.6 | 78.2 | 643.7 | 88.3 | 23.2*** | 0.036 |
Light physical activity (min/day) | 259.8 | 49.0 | 261.8 | 51.3 | 0.2 | – | 268.5 | 46.1 | 250.0 | 55.7 | 19.8*** | 0.031 |
Moderate physical activity (min/day) | 51.4 | 19.5 | 49.7 | 19.2 | 1.1 | – | 47.8 | 18.1 | 54.9 | 20.8 | 19.9*** | 0.031 |
Vigorous physical activity (min/day) | 21.3 | 15.0 | 21.6 | 15.9 | 0.1 | – | 20.1 | 14.6 | 23.9 | 17.0 | 8.5** | 0.014 |
Moderate-to-vigorous physical activity (min/day) | 72.7 | 32.2 | 71.3 | 33.0 | 0.2 | – | 67.9 | 30.7 | 78.7 | 35.3 | 16.2*** | 0.026 |
Cardiorespiratory fitness (laps in 20 m shuttle run test) | 40.0 | 20.7 | 35.0 | 20.1 | 7.8** | 0.013 | 33.5 | 19.5 | 41.7 | 20.8 | 23.0*** | 0.037 |
†N=37 participants had missing values for SES.
‡ N=34 participants had missing values for ethnicity.
*p<0.05, **p<0.01, ***p<0.001.
Age: 10–12 years (n=395), 13–15 years (n=255); sex: boys (n=299), girls (n=351); socioeconomic status: lower (n=194), higher (n=419); ethnicity: black African (n=384), coloured (n=232).
HbA1c, blood glucose; HDL, high-density lipoprotein; LDL, low-density lipoprotein.