[Waist circumference measured before the 12th week of pregnancy: correlation with serum leptin levels]. / Circunferência abdominal avaliada antes da 12(a) semana de gestação: correlação com níveis séricos de leptina.

ABSTRACT

PURPOSE: To evaluate the correlation between maternal waist circumference measured before the 12th week of gestation and serum leptin levels during pregnancy, as well as to compare the leptin levels of women with and without abdominal obesity diagnosed in early pregnancy. METHODS: Prospective study including 40 pregnant women receiving low-risk prenatal care, older than 20 years, nonsmokers, with singleton pregnancies and without chronic disease. Waist circumference was measured before the 12th week and serum leptin levels were measured between the 9th and 12th, 25th and 28th and 34th and 37th weeks of gestation. According to waist circumference measurement, the cohort was divided into two groups with and without abdominal obesity. The Mann-Whitney and χ(2) tests were used to assess the differences between groups. The Pearson correlation coeffient was used to assess the association between waist circumference and serum leptin levels during pregnancy. The level of significance was set at p<0.05. RESULTS: The mean weight and body mass index of patients with abdominal obesity (74.4±11.0 kg/28.9±4.1) was higher than that of patients without abdominal obesity (55.6±5.9 kg/21.1±2.4) (p=0.001). The mean leptin levels in pregnant patients with abdominal obesity (41.9±3.5 ng/mL) was higher than in patients without abdominal obesity (23.6±2.7 ng/mL) (p<0.0002). A positive correlation was obtained between the waist circumference measured during the same period and the mean serum leptin levels (r=0.7; p<0.0001). CONCLUSIONS: Waist circumference measured before the 12th week of pregnancy is a valid and simple method to predict the serum leptin levels throughout pregnancy. Pregnant women with abdominal obesity diagnosed before 12th week have higher mean serum leptin levels during pregnancy than those without abdominal obesity.