Relationship of maternal plasma leptin and risk of pre-eclampsia: a prospective study

We measured maternal plasma leptin concentrations in 55 women with pre-eclampsia and 487 normotensive women to determine whether elevated leptin concentrations were associated with the occurrence of pre-eclampsia.

Maternal blood samples were collected at 13 weeks' gestation, on average. Plasma leptin concentrations were determined using immunoassay. Logistic regression procedures were used to calculate odds ratios (OR) and 95% confidence intervals (95% CI).

Leptin concentrations were 78% higher in cases than control subjects (median 34.6 vs. 19.5 ng/ml; p < 0.001). Relative to women with leptin concentrations of < 27.4 ng/ml, those with elevated leptin concentrations (> or = 27.4 ng/ml) experienced a 2.3-fold increased risk of pre-eclampsia (OR 2.3; 95% CI 1.1-4.6). We observed evidence of a strong linear component of trend in risk of pre-eclampsia with increasing maternal plasma leptin concentration. Each 10-ng/ml increase in leptin concentration was associated with a 30% increase in pre-eclampsia risk (OR 1.3; 95% CI 1.1-1.5). Overweight women with elevated leptin concentrations experienced the highest risk of pre-eclampsia (OR 6.4; 95% CI 3.1-13.2) as compared with lean women with no leptin elevations.

Elevated plasma leptin concentration and maternal overweight status appear to be independently associated with an increased risk of pre-eclampsia.