Table 1.

Mean levels (± SD) of study variables by race, sex and age groups

Variable	White		Black		Race difference
	Males	Females	Males	Females	Males	Females
Childhood (4–11 years)	N=675	N=698	N=473	N=498
Age (year)	9.0±1.7	8.9±1.7	8.8±1.9	8.7±1.9	0.020	0.111
BMI (kg/m2)	18.0±3.4	17.9±3.6	17.7±3.6	17.8±3.6	0.391	0.763
HR (beats/min)	86.4±10.3	89.3±10.3**	82.0±10.1	85.7±10.5**	<0.001	<0.001
Adolescence (12–19 years)	N=511	N=418	N=383	N=310
Age (year)	14.7±2.0	14.8±2.0	15.7±2.2	15.2±2.1**	<0.001	0.010
BMI (kg/m2)	22.5±5.0	22.2±4.8	22.6±5.0	23.1±5.4	0.279	0.052
HR (beats/min)	78.0±10.7	81.7±11.2**	71.8±9.7	78.9±10.4**	<0.001	0.004
Adulthood (20–52 years)	N=714	N=831	N=322	N=449
Age (year)	33.9±9.1	33.3±9.0	32.3±9.4	32.4±9.3	0.007	0.079
BMI (kg/m2)	28.3±6.1	27.2±7.6**	27.2±6.7	29.8±8.3**	0.065	<0.001
HR (beats/min)	69.0±9.1	73.5±9.8**	68.0±9.6	73.0±9.6**	0.147	0.253
Birth registry information	N=1900	N=1947	N=1178	N=1257
Gestational age (week)	39.80±0.82	39.81±0.89	39.66±0.88	39.69±0.90	<0.001	<0.001
Birth weight (kg)	3.46±0.48	3.33±0.47**	3.19±0.51	3.09±0.46**	<0.001	<0.001
Birth weight (kg)a	3.43±0.47	3.31±0.46**	3.17±0.50	3.07±0.45**	<0.001	<0.001

^aAdjusted for gestational age

BMI=body mass index; HR=heart rate

Sex difference within racial groups:

^*p<0.05,

^**p<0.01