Table 1.
Characteristics of study participants
| Variable | Boys (n = 216) | Girls (n = 226) | P-value |
|---|---|---|---|
| Perinatal | |||
| BW (g) | 3217 (644) | 3142 (494) | 0.1 |
| BW z-score | −0.11 | −0.13 | 0.1 |
| Length at birth (cm) | 19.2 (1.0) | 19.7 (1.5) | 0.1 |
| Gestational age (weeks) | 38.6 (2.3) | 39.0 (1.6) | 0.03 |
| Smoking in pregnancy: n (%) | 9 (4) | 18 (8) | 0.09 |
| Maternal education: n (%) | 0.5 | ||
| ≤High school | 31 (14) | 28 (12) | |
| Any college | 185 (86) | 198 (88) | |
| Total household income: n (%) | 0.01 | ||
| <$50,000/year | 57 (26) | 37 (16) | |
| >$50,000/year | 159 (74) | 188 (84) | |
| Maternal pre-pregnancy BMI | 25.6 (6.3) | 25.1 (5.9) | 0.5 |
| Small for gestational age (%) | 28 (13) | 28 (12) | 0.8 |
| Demographic | |||
| Age (years) | 10.6 (1.4) | 10.5 (1.2) | 0.4 |
| Race/ethnicity: n (%) | 0.1 | ||
| NHW | 92 (43) | 118 (52) | |
| Hispanic | 104 (48) | 87 (39) | |
| NHB | 20 (9) | 21 (9) | |
| Tanner stage: n (%) | 0.6 | ||
| <2 | 107 (50) | 108 (48) | |
| ≥2 | 108 (50) | 118 (52) | |
| Physical activity (blocks/day)a | 4.5 (3.0) | 4.1 (2.7) | 0.2 |
| Total calories/day | 1932 (623) | 1709 (489) | <0.0001 |
| % calories from fat/per day | 35.8 (4.9) | 35.4 (4.8) | 0.4 |
| Adiposity | |||
| Weight (kg) | 40.9 (14.5) | 40.0 (12.9) | 0.5 |
| Height (cm) | 144.8 (10.8) | 144.5 (10.2) | 0.7 |
| BMI (kg/m2) | 19.0 (4.7) | 18.9 (4.4) | 0.6 |
| BMI z-score | 0.21 (1.18) | 0.27 (1.2) | 0.3 |
| Waist circumference (cm) | 66.8 (13.0) | 64.5 (11.1) | 0.04 |
| VAT (cm2) | 21.8 (15.2) | 22.8 (17.0) | 0.5 |
| SAT (cm2) | 115.1 (116.2) | 126.9 (101.7) | 0.2 |
| Triceps skinfold (cm) | 15.8 (7.9) | 16.8 (6.6) | 0.1 |
| Subscapular skinfold (cm) | 12.3 (8.9) | 13.4 (8.1) | 0.1 |
| IMCL (mmol/kg muscle wet wt) | 2.3 (1.3) | 0.3 (1.2) | 0.8 |
BW, birth weight; BMI, body mass index; NHW, non-Hispanic white; NHB, non-Hispanic black; VAT, visceral adipose tissue; SAT, subcutaneous adipose tissue; IMCL = intramyocellular accumulation of lipids.
a
Physical activity calculated as average number of 30 min blocks of moderate-to-vigorous activity per day.
All values mean (S.D.) unless otherwise stated.