The relation of menarcheal age to obesity in childhood and adulthood: the Bogalusa heart study

BMC Pediatrics

Table 1 Mean Levels of Various Characteristics in the Study Sample

	Whites	Blacks
N	771	408
Number of examinations	4.6 ± 1*	5.0 ± 1*
2–4 examinations	45%	31%
≥ 5 examinations	55%	69%
Initial examination
Year	1975 ± 3	1973 ± 3
Age (y)	8.7 ± 2	8.9 ± 2
Weight (kg)	29.2 ± 10*	30.6 ± 11*
Weight-for-Age Z^a	-0.2 ± 1*	0 ± 1*
Height (cm)	130 ± 15*	133 ± 15*
Height-for-Age Z^a	-0.2 ± 1**	0.1 ± 1**
BMI (kg/m²)	16.8 ± 3	16.9 ± 3
BMI-for Age Z^a	-0.06 ± 1	-0.05 ± 1
Triceps skinfold thickness (mm)	14 ± 5**	12 ± 5**
Menarcheal age (y)^b	12.9 ± 1	12.8 ± 1
Menarche before age 12 y^b	25%	30%
Final Examination
Age (y)	26 ± 4	26 ± 4
Weight (kg)	66.7 ± 17**	73.5 ± 22**
Height (cm)	163 ± 6	163 ± 7
BMI (kg/m²)	25.1 ± 6**	27.7 ± 8**
Triceps skinfold thickness (mm)	24 ± 10	25 ± 12
Subscapular skinfold (mm)	21 ± 11**	25 ± 13**

^a Z-scores express levels relative to those among children in national studies conducted between 1963 and 1994 (see Methods); ^b Based on data from the first examination at which menarche was first reported. The mean age of girls at this examination was 16 y. H₀: Black vs. white difference equals 0 as assessed by a t-test: *p < 0.05; **p < 0.001

ISSN: 1471-2431