Table 1—

Characteristics and metabolic parameters of the study subjects

Obese subjectsLean subjectsP value*
n2424
Sex (male/female)9/159/15
Age (years)12.52 ± 0.49; 12.00 (9.94–16.23)13.35 ± 0.43; 13.25 (10.04–15.96)0.215
Race
    Caucasian11210.005
    African American111
    Other22
Pubertal stage
    Early puberty (Tanner 1 and 2)66
    Midpuberty (Tanner 3 and 4)77
    Late puberty (Tanner 5)1111
BMI (kg/m2)36.2 ± 2.1; 34.85 (24.84–47.07)18.7 ± 0.6; 18.07 (14.79–22.88)<0.001
BMI z score2.36 ± 0.09; 2.46 (1.55–2.82)−0.28 ± 0.19; −0.31 (−1.36 to 0.79)<0.001
Percentage body fat44.1 ± 1.5; 44.67 (36.39–52.68)22.9 ± 1.1; 23.56 (15.01–29.00)<0.001
Fasting glucose (mmol/l)5.16 ± 0.05; 5.13 (4.55–5.60)5.16 ± 0.10; 5.16 (4.87–5.45)0.984
HbA1c (%)5.24 ± 0.11; 5.20 (4.69–5.62)5.13 ± 0.07; 5.10 (4.69–5.61)0.412
Fasting insulin (pmol/l)178.8 ± 19.8; 186.92 (50.18–268.66)63.2 ± 6.6; 57.47 (25.84–110.2)<0.001
HOMA§6.01 ± 0.76; 5.70 (1.62–9.94)2.10 ± 0.22; 1.86 (0.77–3.54)<0.001
QUICKI§0.31 ± 0.01; 0.30 (0.28–0.36)0.35 ± 0.01; 0.35 (0.32–0.40)<0.001
Cholesterol (mmol/l)4.34 ± 0.16; 4.22 (3.27–5.60)3.76 ± 0.14; 3.63 (2.96–4.88)0.009
Triglycerides (mmol/l)1.12 ± 0.10; 1.07 (0.60–1.83)0.84 ± 0.09; 0.77 (0.48–1.48)0.039
LDL (mmol/l)2.81 ± 0.14; 2.70 (2.03–3.79)2.10 ± 0.12; 2.05 (1.42–3.10)<0.001
HDL (mmol/l)1.10 ± 0.04; 1.06 (0.82–1.35)1.35 ± 0.07; 1.35 (0.96–1.73)0.002
Serum magnesium (mmol/l)0.748 ± 0.015; 0.740 (0.653–0.863)0.801 ± 0.012; 0.822 (0.699–0.863)0.009
Urinary magnesium-to-creatinine ratio (mg/mg)0.077 ± 0.007; 0.067 (0.042–0.112)0.081 ± 0.010; 0.070 (0.040–0.110)0.762
  • Data are means ± SE; median (10th to 90th percentile).

  • *

    * By ANOVA for continuous variables and by exact test for categorical variables.

  • Subject matching criterion by design.

  • Tanner stage of breast development for girls and genital development for boys.

  • §

    § Formulas used for calculation of HOMA and QUICKI are shown in research design and methods.