Person:

Boeke, Caroline E

Objective: We examined associations of perinatal and 3-year leptin with weight gain and adiposity through 7 years. Design and Methods In Project Viva, we assessed plasma leptin from mothers at 26–28 weeks’ gestation (n=893), umbilical cord vein at delivery (n=540), and children at 3 years (n=510) in relation to body mass index (BMI) z-score, waist circumference, skinfold thicknesses, and dual X-ray absorptiometry body fat. Results: 50.1% of children were male and 29.5% non-white. Mean(SD) maternal, cord, and age 3 leptin concentrations were 22.9(14.2), 8.8(6.4), and 1.8(1.7) ng/mL, respectively, and 3- and 7-year BMI z-scores were 0.46(1.00) and 0.35(0.97), respectively. After adjusting for parental and child characteristics, higher maternal and cord leptin was associated with less 3- year adiposity. For example, mean 3-year BMI z-score was 0.5 lower (95%CI:−0.7,−0.2; p-trend=0.003) among children whose mothers’ leptin concentrations were in the top vs. bottom quintile. In contrast, higher age 3 leptin was associated with greater weight gain and adiposity through age 7 [e.g., change in BMI z-score from 3 to 7 years was 0.2 units (95%CI:−0.0,0.4; p-trend=0.05)]. Conclusions: Higher perinatal leptin was associated with lower 3-year adiposity, whereas higher age 3 leptin was associated with greater weight gain and adiposity by 7 years.

Background: Given that it is not feasible to use dual x-ray absorptiometry (DXA) or other reference methods to measure adiposity in all pediatric clinical and research settings, it is important to identify reasonable alternatives. Therefore, we sought to determine the extent to which other adiposity measures were correlated with DXA fat mass in school-aged children. Methods: In 1110 children aged 6.5-10.9 years in the pre-birth cohort Project Viva, we calculated Spearman correlation coefficients between DXA (n=875) and other adiposity measures including body mass index (BMI), skinfold thickness, circumferences, and bioimpedance. We also computed correlations between lean body mass measures. Results: 50.0% of the children were female and 36.5% were non-white. Mean (SD) BMI was 17.2 (3.1) and total fat mass by DXA was 7.5 (3.9) kg. DXA total fat mass was highly correlated with BMI (rs=0.83), bioimpedance total fat (rs=0.87), and sum of skinfolds (rs=0.90), and DXA trunk fat was highly correlated with waist circumference (rs=0.79). Correlations of BMI with other adiposity indices were high, e.g., with waist circumference (rs=0.86) and sum of subscapular plus triceps skinfolds (rs=0.79). DXA fat-free mass and bioimpedance fat-free mass were highly correlated (rs=0.94). Conclusions: In school-aged children, BMI, sum of skinfolds, and other adiposity measures were strongly correlated with DXA fat mass. Although these measurement methods have limitations, BMI and skinfolds are adequate surrogate measures of relative adiposity in children when DXA is not practical.