Table 2

Adjusted* prevalence ratios for body composition and current asthma and adult-onset asthma among California Teachers Study cohort members

Current asthmaAdult-onset asthmaAdult-onset asthma among women not overweight at age 18
OR* (95% CI)OR* (95% CI)OR* (95% CI)
BMI at baseline (kg/m2)
    <18.5 (underweight)1.05 (0.88 to 1.26)1.00 (0.81 to 1.24)1.03 (0.82 to 1.28)
    18.5–24.9 (normal weight)1.001.001.00
    25–29.9 (overweight)1.40 (1.31 to 1.49)1.45 (1.36 to 1.56)1.52 (1.41 to 1.64)
    30–34.9 (obese, class I)1.89 (1.73 to 2.05)1.97 (1.79 to 2.16)2.10 (1.89 to 2.32)
    35–39.9 (obese, class II)2.30 (2.03 to 2.59)2.52 (2.21 to 2.88)2.70 (2.30 to 3.18)
    ⩾40 (obese, class III)3.30 (2.85 to 3.82)3.66 (3.12 to 4.30)4.17 (3.33 to 5.22)
Weight gain since age 18
    Lost weight
    ⩽25th percentile (5 kg)1.001.001.00
    25–49th percentile (5–10 kg)1.20 (1.10 to 1.31)1.20 (1.08 to 1.33)1.19 (1.07 to 1.33)
    50–74th percentile (10.1–18 kg)1.34 (1.27 to 1.52)1.39 (1.26 to 1.54)1.39 (1.25 to 1.55)
    ⩾75th percentile (⩾18.1 kg)2.12 (1.96 to 2.30)2.22 (2.02 to 2.44)2.21 (2.00 to 2.43)
Percentile of waist circumference
    ⩽25th percentile (<72.4 cm)1.001.001.00
    25–49th percentile (72.4–80 cm)1.17 (1.07 to 1.28)1.21 (1.09 to 1.34)1.16 (1.05 to 1.29)
    50–74th percentile (80.1–90 cm)1.46 (1.34 to 1.59)1.54 (1.39 to 1.70)1.49 (1.34 to 1.66)
    ⩾75th percentile (⩾90.1 cm)2.01 (1.85 to 2.18)2.19 (1.99 to 2.41)2.13 (1.92 to 2.37)
Percentile of waist-to-height ratio
    ⩽25th percentile (⩽0.441)1.001.001.00
    25–49th percentile (0.442–0.484)1.28 (1.17 to 1.40)1.38 (1.24 to 1.53)1.37 (1.23 to 1.53)
    50–74th percentile (0.485–0.546)1.49 (1.36 to 1.62)1.61 (1.45 to 1.79)1.59 (1.43 to 1.77)
    ⩾75th percentile (⩾0.547)2.22 (2.04 to 2.41)2.51 (2.27 to 2.77)2.50 (2.25 to 2.79)
  • *Adjusted for race/ethnicity, age group and cigarette smoking.

  • BMI, body mass index.