Association between plasmatic leptin and postpartum weight retention: results from a Brazilian cohort
METHODS: This is a prospective cohort study of 125 healthy pregnant women from Rio de Janeiro, Brazil. Women were followed at 6-13th (baseline), 20-26th, 30-36th gestational weeks and 30-45 days postpartum. Postpartum weight retention was calculated as the difference between postpartum and pre-pregnancy weights at each follow-up visit and was the dependent variable. Plasmatic leptin was evaluated in three points and plasmatic leptin variation coefficient was calculated using linear mixed-effects model. The analyses were stratified by pre-pregnancy BMI (< 25.0 kg/m2 = lean /≥ 25.0 kg/m2= excessive weight). Multiple independent linear regression models were tested having plasmatic leptin levels in baseline and plasmatic leptin variation coefficient. The final models were adjusted for gestational weight gain, maternal age, time of postpartum (days) and energy intake.
RESULTS: The mean postpartum weight retention was 2.67 kg (range: 9.2-14.1) at 36.7 days postpartum. The prevalence of pre-pregnancy excessive weight was 57%. Baseline plasmatic leptin levels were negatively (β= -0.08; 95% CI -0.15-0.016; p=0.01) and leptin variation coefficient was positively (β=0.12; 95% CI 0.04-0.2; p=0.004) associated with postpartum weight retention in normal weight women but no in women with excessive weight. The coefficients of determination of the models were 0.54 (lean) and 0.58 (excessive weight).
CONCLUSIONS: These results suggest that the baseline and the plasmatic leptin variation coefficient during pregnancy may be associated with postpartum weight retention only in women with pre-pregnancy BMI < 25.0 kg/m2.