Table 1

Baseline characteristics of the study cohort according to relative body weight and menopausal status

Premenopausal womenPostmenopausal women
CharacteristicNon-obese* (n=27 712)Pre-obese† (n=10 715)Obese‡ (n=4579)Non-obese* (n=17 818)Pre-obese† (n=28 184)Obese‡ (n=4525)
BMI, body mass index: *BMI <25.0 kg/m2; †BMI 25.0–30 kg/m2; ‡BMI >30.0 kg/m2.
p values for trend (χ2 two sided) were <0.05 for all covariates listed.
Person years298 239113 65948 060189 156108 00346 649
Median BMI (kg/m2)22.326.733.022.326.832.7
Mean age at baseline (y)44.345.045.053.153.853.6
Smoking (% current smokers)22.620.020.124.720.518.1
Education (% post-secondary)35.528.722.925.420.716.4
Oral contraceptive use (%)71.666.562.747.941.537.9
HRT (%)6.47.17.548.747.239.5
Parity (mean No of children)2.22.52.62.52.83.0