Multivariate-adjusted associations between night shift work (continuous years; <20 vs 20+ years) and sex hormones (log-transformed)
| Sex hormone | Continuous shift work (years) | Dichotomous shift work (<20 vs 20+ years), geometric means (95% CI) | ||
| Parameter estimate (p value) | <20 years (n=67) | 20+ years (n=15) | p for Diff | |
| Oestradiol (pmol/l) | −0.002 (0.87) | 259.4 (198.4–338.9) | 269.5 (182.6–397.7) | 0.84 |
| Oestrone (pmol/l) | 0.005 (0.48) | 209.1 (174.3–250.8) | 258.6 (197.9–337.9) | 0.11 |
| Progesterone (nmol/l) | −0.002 (0.86) | 7.0 (4.60–10.8) | 7.5 (4.28–13.2) | 0.79 |
| Prolactin (μg/l) | 0.002 (0.79) | 16.5 (13.4–20.2) | 15.7 (11.8–20.8) | 0.71 |
Adjusted for age (years), body mass index (kg/m2), menstrual cycle stage (follicular, mid-cycle, luteal) and OC use (yes/no), recent alcohol consumption (drinks per day), recent caffeine consumption (drinks per day), smoking status (current/never/former) and total and moderate-to-heavy recent physical activity levels (hours per week), as appropriate.