Plasma leptin influences gestational weight gain and postpartum weight retention

Background: Leptin, a product of the obese (ob) gene, is released from adip ocytes. At the same body mass index, women have higher concentrations than men. Thus, during pregnancy, leptin may influence gestational weight gain a nd retention of a portion of that gain postpartum. Objective: We examined the relation between plasma leptin at entry to prena tal care and subsequent changes in weight from entry to prenatal care (at 1 7 wk gestation, baseline) until 6 mo postpartum. Design: This was an observational study of leptin, gestational weight gain, and postpartum weight retention (at 6 wk and 6 mo postpartum) in 103 low-i ncome pregnant women from Camden, NJ, with a pregravid body mass index (in kg/m(2)) in the normal range (19.8-26). Results: After potential confounding variables were controlled for, leptin at entry significantly (P < 0.05) predicted weight gain in pregnancy, inclu ding measured rate of weight gain ((x) over bar +/- SEE: 0.25 +/- 0.13 kg.u nit log leptin(-1) wk(-1)), measured rate of third-trimester weight gain (0 .37 +/- 0.15 kg.unit log leptin(-1).wk(-1)), rate of weight gain from recal led pregravid weight (0.23 +/- 0.09 kg unit log leptin(-1).wk(-1)), and net rate of gestational weight gain (0.22 +/- 9.09 kg.unit log leptin(-1).wk(- 1)). The leptin concentration at entry also significantly predicted retaine d weight in the postpartum period (at 6 mo: 7.29 +/- 3.33 kg/unit log lepti n at entry) and marginally predicted changes in the sum of skinfold thickne sses (at 6 mo: 14.7 +/- 7.5 mm/unit log leptin at entry). Conclusion: These results suggest that a high leptin concentration at entry to prenatal care may predict an increased risk of overweight and obesity i n vulnerable women.