Table 2.
Mutually Adjusted Associations of MRI Breast Volume and Percent Water With Observed Measurements of Height, Weight, and Dual-Energy x-Ray Absorptiometry Percent Body Fat and Bone Masses and With Markers of Pubertal Development, Avon Longitudinal Study of Parents and Children, 1991–2014a
| Variableb | MRI Breast Volume, cm3 | MRI Percent Water | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Model 1c (n = 287) | Model 2d (n = 261) | Model 3e (n = 244) | Model 1c (n = 287) | Model 2d (n = 261) | Model 3e (n = 244) | |||||||
| RCf | 95% CI | RC | 95% CI | RC | 95% CI | RC | 95% CI | RC | 95% CI | RC | 95% CI | |
| Birth length, cm | 1.00 | 0.93, 1.08 | 1.05 | 0.97, 1.14 | 1.02 | 0.95, 1.10 | 1.01 | 0.98, 1.05 | 0.99 | 0.96, 1.02 | 1.00 | 0.97, 1.03 |
| Prepubertal height growth, cmg | 0.86h | 0.74, 1.00 | 0.88 | 0.75, 1.03 | 0.93 | 0.78, 1.11 | 1.12h | 1.04, 1.20 | 0.95 | 0.90, 1.01 | 0.93 | 0.87, 1.00 |
| Pubertal height growth, cmi | 0.84h | 0.75, 0.94 | 0.90 | 0.81, 1.01 | 0.89 | 0.78, 1.01 | 1.07h | 1.02, 1.14 | 1.07h | 1.03, 1.12 | 1.07h | 1.02, 1.13 |
| Birth weight, kg | 0.99 | 0.92, 1.06 | 0.98 | 0.91, 1.05 | 1.00 | 0.93, 1.07 | 1.03 | 1.00, 1.07 | 1.03 | 1.00, 1.06 | 1.03h | 1.00, 1.06 |
| Prepubertal weight growth, kgj | 1.22h | 1.13, 1.32 | 1.21h | 1.07, 1.37 | 1.15h | 1.02, 1.30 | 0.87h | 0.84, 0.90 | 1.05 | 1.00, 1.10 | 1.05 | 1.00, 1.11 |
| Pubertal weight growth, kgk | 1.78h | 1.68, 1.89 | 1.67h | 1.56, 1.80 | 1.70h | 1.58, 1.82 | 0.84h | 0.82, 0.87 | 0.86h | 0.84, 0.89 | 0.86h | 0.84, 0.89 |
| Age at menarche, years | 1.04 | 0.97, 1.12 | 1.05 | 0.97, 1.14 | 1.00 | 0.97, 1.04 | 1.00 | 0.97, 1.03 | ||||
| Age at thelarche, yearsl | 1.01 | 0.87, 1.16 | 1.04 | 0.88, 1.22 | 1.06 | 0.99, 1.14 | 1.02 | 0.96, 1.09 | ||||
| Age at completion of breast development, yearsl | 0.88h | 0.83, 0.93 | 0.88h | 0.83, 0.94 | 1.00 | 0.97, 1.02 | 1.01 | 0.98, 1.03 | ||||
| DXA body fat mass, %m | ||||||||||||
| At age 9 years | 1.11 | 1.00, 1.23 | 1.13h | 1.02, 1.25 | 0.86h | 0.83, 0.90 | 0.86h | 0.83, 0.90 | ||||
| Between ages 9 and 11 years | 1.04 | 0.96, 1.13 | 1.03 | 0.96, 1.11 | 0.94h | 0.92, 0.97 | 0.95h | 0.92, 0.98 | ||||
| Between ages 11 and 13.5 years | 1.07 | 0.99, 1.15 | 1.08 | 1.00, 1.16 | 0.96h | 0.93, 0.98 | 0.96h | 0.93, 0.99 | ||||
| Between ages 13.5 and 15.5 years | 0.98 | 0.92, 1.04 | 0.98 | 0.93, 1.04 | 0.99 | 0.96, 1.01 | 0.99 | 0.97, 1.02 | ||||
| DXA body bone mass, %m | ||||||||||||
| At age 9 years | 1.01 | 0.94, 1.09 | 1.02 | 0.95, 1.09 | 1.03h | 1.00, 1.06 | 1.03h | 1.00, 1.06 | ||||
| Between ages 9 and 11 years | 0.96 | 0.90, 1.02 | 0.96 | 0.90, 1.03 | 1.01 | 0.99, 1.04 | 1.02 | 0.99, 1.04 | ||||
| Between ages 11 and 13.5 years | 0.93 | 0.86, 1.00 | 0.96 | 0.88, 1.03 | 0.97 | 0.95, 1.00 | 0.98 | 0.95, 1.01 | ||||
| Between ages 13.5 and 15.5 years | 0.91h | 0.86, 0.97 | 0.91h | 0.86, 0.97 | 1.01 | 0.98, 1.03 | 1.01 | 0.99, 1.04 | ||||
Abbreviations: CI, confidence interval; DXA, dual-energy x-ray absorptiometry; MRI, magnetic resonance imaging; RC, relative change.
a MRI breast measurements were log-transformed. Exponentiated estimated regression parameters are presented; 95% CIs were calculated by exponentiating the original 95% CIs. RC estimates were adjusted for age and menstrual cycle phase at MRI examination and all of the other variables included in the model.
b All growth variables, as well as growth differences across ages, were standardized (see Methods section).
c Model 1 included all of the height/weight growth trajectory variables and the pubertal development variables.
d Model 2 included all of the height/weight growth trajectory variables and the DXA measures.
e Model 3 included all of the height/weight growth trajectory variables, the pubertal development variables, and the DXA measures.
f Relative change per 1–standard-deviation increment in the exposure variable of interest.
g Prepubertal height growth was calculated as height at age of thelarche minus height at age 7 years (±1 year).
hP < 0.05.
i Pubertal height growth was calculated as height at age 21 years minus height at age of thelarche.
j Prepubertal weight growth was calculated as weight at age of thelarche minus weight at age 7 years (±1 year).
k Pubertal weight growth was calculated as weight at age 21 years minus weight at age of thelarche.
l Age at thelarche and age at completion of breast development were estimated as described in the Methods section.
m DXA percent body fat and bone masses were estimated as described in the Methods section. These models included the relevant DXA measurements taken at age 9 years and changes in these measurements between ages 9 and 11 years, between ages 11 and 13.5 years, and between ages 13.5 and 15.5 years.