Introduction
Methods
Subjects
Measurements
Statistical analyses
Results
Descriptives
Girls | Boys | |||||||||
---|---|---|---|---|---|---|---|---|---|---|
TFF1 | TFF2 | TFF1 | TFF2 | |||||||
n
|
n
|
p
|
n
|
n
|
p
| |||||
Age | 358 | 16.61 (0.387) | 358 | 18.60 (0.40) | 296 | 16.60 (0.367) | 296 | 18.65 (0.35) | ||
Age groups at baseline | ||||||||||
15 | 9 | 2.5% | 19 | 6.4% | ||||||
16 | 296 | 82.7% | 238 | 80.4% | ||||||
17 | 53 | 14.8% | 39 | 13.2% | ||||||
Height (cm) | 358 | 165.07 (6.47) | 358 | 165.77 (6.56) | <0.001 | 296 | 177.25 (6.52) | 296 | 179.08 (6.49) | <0.001 |
Weight (kg) | 358 | 60.42 (10.61) | 358 | 63.11 (11.91) | <0.001 | 296 | 69.81 (13.68) | 296 | 75.21 (14.64) | <0.001 |
Sexual maturationa
| ||||||||||
Early/completed | 110 | 31.3% | 22 | 9.1% | ||||||
Intermediate/underway | 168 | 47.9% | 177 | 72.8% | ||||||
Late/barely started | 73 | 20.8% | 44 | 18.1% | ||||||
Ethnicity | ||||||||||
White | 350 | 97.8% | 291 | 98.3% | ||||||
Others | 8 | 2.2% | 5 | 1.7% | ||||||
Physical activity | ||||||||||
Sedentary | 43 | 12.0% | 47 | 13.3% | 77 | 26.3% | 81 | 28.4% | ||
Moderate | 141 | 39.5% | 144 | 40.8% | 75 | 25.6% | 60 | 21.1% | ||
Sports | 110 | 30.8% | 110 | 31.2% | 71 | 24.2% | 77 | 27.0% | ||
Competition | 63 | 17.6% | 52 | 14.7% | 70 | 23.9% | 67 | 23.5% | ||
Smoking (yes) | 68 | 19.0% | 102 | 28.5% | <0.001 | 62 | 20.9% | 114 | 38.5% | <0.001 |
Snuff use (yes) | 108 | 30.2% | 152 | 42.5% | <0.001 | 108 | 36.5% | 142 | 48.0% | <0.001 |
Alcohol consumption (yes) | 262 | 73.2% | 336 | 93.9% | <0.001 | 195 | 65.9% | 272 | 91.9% | <0.001 |
Diseases known to affect boneb (yes) | 4 | 1.1% | 5 | 1.7% | ||||||
Medication known to affect bonec (yes) | 8 | 2.2% | 6 | 2.0% | ||||||
Hormonal contraceptive use (yes) | 118 | 33.0% | ||||||||
Estrogen and progestogens | 105 | 29.3% | ||||||||
Progestogens only | 13 | 3.6% |
Changes in bone traits and anthropometry
Tracking from baseline to follow-up
Predictors of positive deviation from tracking
Girls | Boys | |||||||||
---|---|---|---|---|---|---|---|---|---|---|
TFF1 | TFF2 | TFF1 | TFF2 | |||||||
n
|
n
|
p
|
n
|
n
|
p
| |||||
aBMD FN (g/cm2) | 358 | 1.07 (0.13) | 357 | 1.08 (0.13) | 0.008 | 296 | 1.11 (0.15) | 296 | 1.14 (0.15) | <0.001 |
aBMD TH (g/cm2) | 357 | 1.06 (0.13) | 357 | 1.07 (0.13) | <0.001 | 296 | 1.12 (0.15) | 296 | 1.14 (0.16) | <0.001 |
aBMD TB (g/cm2) | 357 | 1.14 (0.08) | 358 | 1.16 (0.07) | <0.001 | 296 | 1.18 (0.10) | 296 | 1.23 (0.09) | <0.001 |
BMC FN (g) | 358 | 4.92 (0.71) | 357 | 4.94 (0.72) | <0.001 | 296 | 5.99 (0.99) | 296 | 6.19 (0.99) | <0.001 |
BMC TH (g) | 357 | 32.03 (4.84) | 357 | 32.42 (4.95) | <0.001 | 296 | 40.17 (6.64) | 296 | 41.26 (6.86) | <0.001 |
BMC TB (g) | 357 | 2524.06 (388.27) | 358 | 2600.95 (381.68) | <0.001 | 296 | 2963.78 (469.83) | 296 | 3200.96 (476.10) | <0.001 |
BA FN (cm2) | 358 | 4.60 (0.34) | 357 | 4.60 (0.34) | 0.866 | 296 | 5.38 (0.39) | 296 | 5.41 (0.37) | 0.003 |
BA TH (cm2) | 357 | 30.15 (2.32) | 357 | 30.22 (2.38) | 0.068 | 296 | 35.73 (2.47) | 296 | 35.99 (2.51) | <0.001 |
BA TB (cm2) | 357 | 2207.37 (233.59) | 358 | 2241.68 (224.95) | <0.001 | 296 | 2496.46 (240.06) | 296 | 2598.28 (237.87) | <0.001 |
Time between measurements (years) | 358 | 1.94 (0.20) | 296 | 2.01 (0.23) |
Girls | Boys | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
FN (n = 183 vs 167) | TH (n = 182 vs 167) | TB (n = 170 vs 180) | FN (n = 117 vs 123) | TH (n = 127 vs 114) | TB (n = 112 vs 129) | |||||||
OR (95% CI) |
p
| OR (95% CI) |
p
| OR (95% CI) |
p
| OR (95% CI) |
p
| OR (95% CI) |
p
| OR (95% CI) |
p
| |
Age (year) | 0.64 (0.35, 1.16) | 0.142 |
0.43 (0.24, 0.79)
|
0.007
| 0.71 (0.39, 1.29) | 0.265 |
a
| 0.56 (0.23, 1.37) | 0.205 | 0.56 (0.23, 1.38) | 0.211 | |
Height (cm) | 1.00 (0.96, 1.04) | 0.855 | 1.01 (0.97, 1.04) | 0.805 | 1.02 (0.98, 1.06) | 0.390 | 1.00 (0.95, 1.05) | 0.988 | 1.00 (0.95, 1.05) | 0.988 |
1.06 (1.01, 1.11)
|
0.023
|
Weight (10 kgb) | 1.00 (0.98, 1.03) | 0.711 | 1.00 (0.82, 1.32) | 0.744 | 1.23 (0.93, 1.61) | 0.143 |
a
|
1.36 (1.05, 1.76)
|
0.018
| 1.21 (0.94, 1.57) | 0.141 | |
Z-score at baseline |
0.74 (0.58, 0.96)
|
0.022
|
0.74 (0.57, 0.97)
|
0.026
|
0.66 (0.49, 0.88)
|
0.005
|
0.67 (0.47, 0.94)
|
0.021
|
0.64 (0.45, 0.90)
|
0.011
|
0.50 (0.35, 0.72)
|
0.000
|
Sexual maturation | Reference: menarche age <12.5 years | Reference: pubertal development completed | ||||||||||
Intermediate/underway | 1.41 (0.84, 2.37) | 0.198 | 1.24 (0.73, 2.11) | 0.420 | 1.28 (0.75, 2.18) | 0.376 | 2.55 (0.84, 7.74) | 0.098 | 1.55 (0.56, 4.23) | 0.399 | 1.09 (0.52, 5.87) | 0.871 |
Late/just started | 1.68 (0.88, 3.20) | 0.114 | 1.68 (0.87, 3.21) | 0.120 |
2.05 (1.05, 3.98)
|
0.035
| 2.44 (0.67, 8.61) | 0.167 | 1.50 (0.46, 4.90) | 0.502 | 1.74 (0.52, 5.87) | 0.371 |
Hormonal contraceptive use | Reference: no contraceptive use | |||||||||||
Estrogen and progestogen |
0.60 (0.36, 1.00)
|
0.048
| ||||||||||
Progestogen only | 0.79 (0.24, 2.55) | 0.687 | ||||||||||
Physical activity | Reference: sedentary | |||||||||||
Moderate | 1.94 (0.93, 4.06) | 0.080 | 1.52 (0.72, 3.21) | 0.278 | 1.78 (0.82, 3.86) | 0.147 | 0.62 (0.27, 1.40) | 0.276 | 0.61 (0.26, 1.39) | 0.237 | 0.53 (0.23, 1.20) | 0.128 |
Sports | 1.79 (0.82, 3.90) | 0.143 | 1.64 (0.75, 3.61) | 0.217 |
4.07 (1.78, 9.30)
|
0.001
| 0.56 (0.24, 1.30) | 0.138 | 0.80 (0.34, 1.85) | 0.594 | 0.71 (0.31, 1.62) | 0.414 |
Competition | 1.95 (0.80, 4.72) | 0.140 | 1.24 (0.51, 3.01) | 0.640 |
3.28 (1.31, 8.20)
|
0.011
| 0.83 (0.35, 2.00) | 0.680 | 0.70 (0.29, 1.73) | 0.443 | 1.45 (0.62, 3.40) | 0.390 |
Snuff use c
| 0.93 (0.52, 1.66) | 0.802 |
0.50 (0.28, 0.89)
|
0.019
| 1.09 (0.61, 1.94) | 0.769 | 0.77 (0.35, 1.68) | 0.513 | 0.71 (0.32, 1.54) | 0.384 | 0.61, (0.27, 1.35) | 0.221 |
Smoking c
| 0.80 (0.42, 1.54) | 0.510 | 1.03 (0.54, 1.99) | 0.919 | 1.17 (0.61, 2.34) | 0.645 | 0.53 (0.22, 1.30) | 0.166 | 0.43 (0.18, 1.04) | 0.062 | 0.47 (0.19, 1.15) | 0.097 |
Alcohol consumption c
| 1.03 (0.60, 1.78) | 0.913 | 1.24 (0.71, 2.15) | 0.450 |
0.45 (0.26, 0.80)
|
0.006
| 0.87 (0.45, 1.67) | 0.674 | 0.84 (0.43, 1.64) | 0.611 | 1.55 (0.80, 2.99) | 0.193 |