Table 1. Principal clinical characteristics of Korean adolescents in the 2009–2010 Korean National Health and Nutrition Examination Survey.
| Boys | Girls | P-value* | |
|---|---|---|---|
| (n = 1026) | (n = 853) | ||
| Place (Rural,yes, %) † | 83.6(2.7) | 82(3.4) | 0.492 |
| Smoking (yes, %) | 19.3(1.6) | 6.6(1.2) | <0.001 |
| Alcohol intake (yes, %) | 25.9(1.7) | 17.6(2) | 0.002 |
| Physical activity (%)** | <0.001 | ||
| Sedentary | 31.6(1.6) | 43.6(2.1) | |
| Minimally active | 41.6(1.9) | 44.5(2.1) | |
| Health-enhancing activity | 26.8(1.6) | 11.8(1.5) | |
| Monthly income (lowest quartile, %) | 14.5(1.6) | 14.3(1.9) | 0.912 |
| Menarche (yes) | NA | 76.3(2) | . |
| Age (years) | 14.2±0.1 | 14±0.1 | 0.135 |
| Height (cm) | 165.4±0.5 | 157.3±0.4 | <0.001 |
| Weight (kg) | 58.1±0.6 | 50.3±0.5 | <0.001 |
| BMI (kg/m2) | 21±0.1 | 20.2±0.2 | 0.001 |
| SBP (mmHg) | 110±0.4 | 104.2±0.4 | <0.001 |
| DBP (mmHg) | 68.9±0.4 | 66.8±0.4 | <0.001 |
| FBG (mg/dL) | 89.3±0.3 | 88.3±0.3 | 0.002 |
| TC (mg/dL) | 152.9±1.2 | 163.1±1 | <0.001 |
| LDL-C (mg/dL) | 83.9±1.1 | 90.2±0.9 | <0.001 |
| HDL-C (mg/dL) | 52.1±0.4 | 55.5±0.5 | <0.001 |
| TG (mg/dL) | 73.7(70.6–77) | 77.2(74.2–80.3) | 0.084 |
| 25(OH)D3 (ng/mL) | 17.1±0.3 | 16.3±0.3 | 0.006 |
| FSI (μIU/mL) | 12(11.7–12.4) | 12.9(12.4–13.4) | 0.005 |
| HOMA-IR | 2.6(2.6–2.7) | 2.8(2.7–2.9) | 0.031 |
| Hemoglobin (g/dL) | 14.6±0 | 13.4±0 | <0.001 |
| Hematocrit (%) | 43.3±0.1 | 40.1±0.1 | <0.001 |
| Serum ferritin (ng/mL) | 42.7(40.7,44.9) | 26.9(25.4,28.6) | <0.001 |
| ALT (IU/L) | 14.7(14.1–15.3) | 10.9(10.6–11.2) | <0.001 |
| AST (IU/L) | 19.4(19–19.8) | 17(16.7–17.3) | <0.001 |
| Daily energy intake (kcal) | 2290.9±39.3 | 1843.6±35.7 | <0.001 |
| Daily protein intake (%) | 14.3±0.2 | 13.7±0.2 | 0.013 |
| Daily fat intake (%) | 22.6±0.3 | 22.6±0.4 | 0.923 |
| Daily intake of calcium (mg) | 539.4±15.7 | 450.6±13.8 | <0.001 |
Abbreviations: BMI, body mass index; SBP, systolic blood pressure; DBP, diastolic blood pressure; FBG, fasting blood glucose; TC, total cholesterol; LDL-C, low-density lipoprotein-cholesterol; HDL-C, high-density lipoprotein cholesterol; TG, triglyceride; 25(OH)D3, 25-hydroxyvitamin D3; FSI, fasting serum insulin; HOMA-IR, homeostasis model assessment of insulin resistance; ALT, alanine transaminase; AST, aspartate transaminase; NA, not applicable.
Data are presented as mean ± standard error (SE) or percentage ±SE.
TG, AST, ALT, FSI levels, and HOMA-IR were tested after logarithmic transformation.
* P-values were obtained by using the chi-square test or Student’s t-test.
** Study subjects were categorized according to their physical activity levels as follows: sedentary, < 600 metabolic equivalents (METs)/week; minimally active, 600–3000METs/week; and health-enhancing physical activity, > 3000METs/week.
† Place means the area of residence and was categorized into rural and urban area. Urban area included metropolitan cities and province such as ward and county were classified into rural area.