Abdominal obesity adversely affects bone mass in children

Table 1 Descriptive data of the overweight and normal weight groups

Covariates	Overweight n = 23	Normal weight n = 14	P value
	mean (SD)	mean (SD)
Age (mo)	187 (25.4)	198 (31.1)	0.40b
Gender (% age females)	43.48%	57.14%	0.42
Birth weight (g)	3385 (644)	3179 (908)	0.42b
Weight (kg)	93.7 (19.9)	57.4 (7.51)	< 0.0001a
Weight %ile	95.1 (6.35)	52.5 (20.8)	< 0.0001b
Height (cm)	168 (9.90)	167 (6.92)	0.72a
Height %ile	59.3 (30.5)	60.1 (31.2)	0.88b
BMI kg/m2	32.9 (5.60)	20.5 (1.51)	< 0.0001a
BMI %ile	96.6 (3.17)	47.3 (17.1)	< 0.0001b
Total activity time/d (min)	303 (125)	307 (109)	0.93
Apolipoprotein C III (mg/dL)	6.71 (1.53)	6.56 (140)	0.75a
C-reactive protein	2.81 (2.85)c	2.61(2.41)d	0.86
HOMA-IR	3.23 (1.78)	2.49 (3.49)	0.02
Waist circumference (cm)	98.5 (13.7)	69.2 (5.79)	< 0.0001a
Hip circumference (cm)	118 (11.4)	94.8 (5.72)	< 0.0001a
Waist to hip ratio	0.84 (0.06)	0.73 (0.05)	< 0.0001a
Total lean mass (kg) (DXA)	50.58 (10.78)	55.40 (12.68)	0.23a
Percent trunk fat (DXA)	36.4 (9.3)	17.1 (6.49)	< 0.0001
Spine BMD (g/cm2)	1.06 (0.14)	1.06 (0.13)	0.95a
BMD L-spine Z-score	1.32 (1.24)	1.36 (1.00)	0.92
Whole body BMD (g/cm2)	1.10 (0.09)	1.06 (0.07)	0.21a
Whole body BMC (g)	2417 (408)	2116 (281)	0.02a

^aStudent’s t-test;

^bWilcoxon-Mann-Whitney test;

^cn = 16;

^dn = 9. SD: Standard deviation; HOMA-IR: Homeostatic model assessment-estimated insulin resistance; BMD: Bone mineral density; BMC: Bone mineral content; BMI: Body mass index.

Table 2 Robust regression with whole body bone mineral content or spine bone mineral density as the dependent variable after controlling for other covariates in the model

Variable	Whole body BMC		Spine BMD
	β	P value	β	P value
Gender	-704.28	< 0.0001	0.0876	0.18
Activity time % of day	-0.55	0.79	-0.0003	0.86
Waist to hip ratio	-111.619	0.86	0.4707	0.27
Percent trunk fat	-2112.67	< 0.0001	-0.3706	0.18
Total lean mass	-0.0022	0.59	0.00	0.98
HOMA IR	123.3	< 0.0001	-0.1295	0.29

Other covariates in the model include waist to hip ratio, truck to total fat ratio, total lean mass, CRP, total activity time, apo CIII ratio, gender, HOMA-IR. BMC: Bone mineral content; BMD: Bone mineral density; HOMA-IR: Homeostatic model assessment-estimated insulin resistance.