Women who reported consuming at least two portions of seafood (white fish, oily fish or other seafood) per week had a significantly higher concentration of Se in both whole blood and toenails ( P = 0·001 for each); the significance disappeared after adjustment, but remained close to significance for whole-blood Se concentration ( P = 0·054).
Logistic regression on risk factors assessed individually showed that DBP, BMI and toenail Se concentration were the only factors that significantly affected the combined PE/PIH outcome; both SEPP1 concentration and treatment failed to reach significance (see Table 3 ).
When a stepwise model was run with only significant or near-significant factors entered into the model (SEPP1 was excluded as it was highly associated with treatment: mean 5·13 v . 2·95 mg/l for the Se-treated and placebo groups, respectively, P < 0·0005), baseline DBP (OR 1·10, 95 % CI 1·03, 1·18), BMI (OR 1·13, 95 % CI 1·00, 1·27) and toenail Se concentration (OR 0·38, 95 % CI 0·17, 0·87) remained significant, with treatment again failing to reach significance ( P = 0·067) (adjusted model 1; Table 3 ).