Evaluation of Growth Patterns and Body Composition in C57Bl/6J Mice Using Dual Energy X-Ray Absorptiometry

Table 1

Mean and standard deviation values for morphometric and body composition measurements in female C57BL/6J mice from 5 to 30 weeks of age.

Age (weeks)	5	9	13	17	21	25	30
Female number	20	20	20	5	10	5	5
Body weight, g	16.15±0.64	19.98±0.91^∗∗	21.33±0.67	22.40±0.54	24.04±0.90^∗	26.16±0.48	27.64±1.42^∗
Body surface area, cm^2	51.13±0.74	56.66±0.94^∗∗	63.00±1.98	63.20±1.64	67.30±0.89^∗	74.38±1.52	79.57±2.15^∗
BMI, g/cm^2	3.16±0.08	3.52±0.11^∗∗	3.38±0.10	3.54±0.01	3.57±0.02^∗	3.51±0.05	3.47±0.01
BMC, g	0.285±0.075	0.394±0.025^∗∗	0.438±0.024	0.465±0.025	0.447±0.035^∗	0.467±0.028	0.468±0.054
BMC corr, g/m^2	55.85±15.27	69.62±4.93	69.60±11.38	73.65±4.88	68.50±3.43^∗	62.88±4.55	58.96±7.13
BMD, g/cm^2	0.0391±0.0042	0.0460±0.0019^∗∗	0.0483±0.0015	0.0548±0.0011	0.0511±0.0023^∗	0.0528±0.0011	0.0510±0.0049
ΔBMD/1 week age, %		+4.4	+1.3	+3.4	−1.7	+0.80	−0.7
BMD corr, g/cm^2*m	0.55±0.06	0.61±0.02	0.60±0.02	0.69±0.02	0.62±0.03^∗	0.61±0.18	0.57±0.05
LM, g	12.8±0.7	15.8±0.8^∗∗	17.2±0.8	17.7±0.6	17.8±1.2	20.5±0.3	21.7±1.4^∗
ΔLM/1 week age, %		+5.9	+2.2	+0.7	+0.1	+3.8	+1.2
LMI, g/cm^2	0.250±0.012	0.279±0.010^∗∗	0.264±0.005	0.279±0.010	0.284±0.009	0.281±0.008	0.272±0.013^∗
FM, g	2.2±0.3	2.1±0.2	2.0±0.4	3.6±0.7	3.7±0.7^∗	3.9±0.9	4.2±0.7^∗
FM, %	14.90±1.70	11.74±1.00^∗∗	10.45±1.74	16.92±2.31	15.70±3.53^∗	15.70±3.17	16.19±2.37
ΔFM/1 week age, %		−1.1	−1.2	+20.0	−0.7	1.4	+1.5
FMI, g/cm^2	0.043±0.005	0.037±0.003^∗∗	0.040±0.005	0.058±0.009	0.045±0.012^∗	0.052±0.011	0.052±0.008

^∗𝑃≤0.01; ^∗∗𝑃<0.001; Wilcoxon-signed rank test (5–9 weeks) and nonparametric Friedmans ANOVA (9–13–17–21/13–21–25–30 weeks) on serial data.
BMI: body mass index; BMC: bone mineral content; BMC corr: correct projected areal bone mineral content; BMD: bone mineral density; BMD corr: correct projected areal bone mineral density; LM: lean mass; LMI: lean mass index; FM: fat mass; FMI: fat mass index, Δ : mean value difference/1-week age.