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Table 2 Characteristics of the twin and later-life environment (n = 332 individuals and residences)

From: Early-life residential green spaces and traffic exposure in association with young adult body composition: a longitudinal birth cohort study of twins

 

Total

 

Type of twin

  
 

n/N

 

MZMC n = 106 (31.9%)

MZDC n = 108 (32.5%)

DZ n = 118 (35.5%)

Characteristics of the twin population

332

    

 Sex (female), n (%)

332/332

173 (52.1%)

50 (47.2%)

64 (59.3%)

59 (50%)

 Birthweight (g), mean + SD

332/332

2545 + 505

2507 + 429

2536 + 598

2589 + 476

Characteristics of the twin population at adulthood

     

 Age (years), median (p25-p75)

332/332

20.7 (19.4–22.0)

20.9 (19.4–22.0)

20.5 (19.3–22.5)

20.7 (19.7–22.2)

 BMI (kg/m2), median (p25-p75)

332/332

20.7 (19.3–22.7)

20.8 (19.3–22.3)

20.5 (19.1–22.6)

20.7 (19.4–22.9)

  Underweight (BMI < 18.5)

 

45 (13.6%)

17 (16.0%)

16 (14.8%)

12 (10.2%)

  Normal (BMI 18.5–24.9)

 

256 (77.1%)

84 (79.2%)

81 (75%)

91 (77.1%)

  Overweight (BMI 25–29.9)

 

31 (9.3%)

5 (4.7%)

11 (10.2%)

15 (12.7%)

  Obese (BMI > 30.0)

 

2 (0.6%)

0 (0.0%)

0 (0.0%)

2 (1.7%)

 Leptin (ng/ml), median (p25-p75)

319/332

4.7 (1.1–11.0)

4.4 (1.0–9.5)

5.4 (1.6–12.0)

4.4 (0.9–11.9)

 Waist-to-hip ratio (%), median (p25-p75)

330/332

76.0 (71.7–80.1)

76.9 (71.7–80.4)

75.7 (71.3–79.2)

75.7 (72.3–80.1)

 Waist circumference (cm), median (p25-p75)

331/332

70.5 (66.4–75.3)

71.5 (66.4–75.2)

69.3 (66.1–75.2)

70.8 (67.0–75.3)

 Skinfold thickness (mm), median (p25-p75)

331/332

38.0 (27.6–51.8)

35.0 (27.8–49.9)

41.6 (28.4–55.0)

37.6 (27.3–52.3)

 Body fat (%), median (p25-p75)

330/332

22.5 (14.9–27.4)

22.4 (14.8–26.1)

23.3 (15.9–27.7)

21.7 (14.6–28.4)

 Physical activity score, median (p25-p75)

332/332

4.9 (3.0–6.6)

5.0 (3.0–7.0)

4.3 (2.9–6.4)

5.0 (3.1–6.9)

 Smoking status, n (%)

332/332

    

  Nonsmoker

 

201 (60.5%)

66 (62.3%)

36 (33.3%)

69 (58.5%)

  Former smoker

 

21 (6.3%)

5 (4.7%)

6 (5.6%)

10 (8.5%)

 Current smoker

 

110 (33.1%)

35 (33.0%)

36 (61.1%)

39 (33.1%)

Environmental exposures during adulthood

  

 Distance from residence to nearest road (m), median (p25-p75)

321/332

345 (139–770)

385 (134.8–884.7)

344.5 (135.8–722.4)

340.4 (144.3–770.3)

 Distance from residence to nearest highway (m), median (p25-p75)

321/332

3964 (1866–7874)

2987 (1916–7344)*

6288 (2500–10,566)*

2839 (1556–5399)*

 Green spaces within a 5000 m buffer from the home address (%), median (p25-p75)

321/332

4.2 (2.9–6.4)

4.2 (2.8–6.5)

4.9 (3.1–7.2)

3.9 (3.0–5.5)

  1. Abbreviations: n number without missing data, N total number of mothers included, MZMC monozygotic monochorionic, MZDC monozygotic dichorionic, DZ dizygotic; p25 25th percentile, p75 75th percentile
  2. *p-value< 0.05 of Chi-square test or Kruskall-Wallis test
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Environmental Health

ISSN: 1476-069X