Ethnic differences in the accumulation of fat and lean mass in late gestation

Abstract

Objectives Lower birth weight within the normal range predicts adult chronic diseases, but the same birth weight in different ethnic groups may reflect different patterns of tissue development. Neonatal body composition was investigated among non-Hispanic Caucasians and African Americans, taking advantage of variability in gestational duration to understand growth during late gestation. Methods Air displacement plethysmography assessed fat and lean body mass among 220 non-Hispanic Caucasian and 93 non-Hispanic African American neonates. The two ethnic groups were compared using linear regression. Results At 36 weeks gestation, the average lean mass of Caucasian neonates was 2,515 g vs. that of 2,319 g of African American neonates (difference, P = 0.02). The corresponding figures for fat mass were 231 and 278 g, respectively (difference, P = 0.24). At 41 weeks, the Caucasians were 319 g heavier in lean body mass (P < 0.001) but were also 123 g heavier in fat mass (P = 0.001). The slopes for lean mass vs. gestational week were similar, but the slope of fat mass was 5.8 times greater (P = 0.009) for Caucasian (41.0 g/week) than for African American neonates (7.0 g/week). Conclusions By 36 weeks of gestation, the African American fetus developed similar fat mass and less lean mass compared with the Caucasian fetus. Thereafter, changes in lean mass among the African American fetus with increasing gestational age at birth were similar to the Caucasian fetus, but fat accumulated more slowly. We hypothesize that different ethnic fetal growth strategies involving body composition may contribute to ethnic health disparities in later life.

Intergenerational effects of in utero exposure to Ramadan in Tunisia

“…We suggest that maternal exposure to Ramadan in utero has different effects in the two countries because fetal growth trajectories differ. Ethnic differences in fetal growth trajectories have been reported previously (Lampl et al, 2012). Sex differences in fetal growth trajectories have also been reported .…”

Body composition assessment in the infant

“…Most anthropometric body composition prediction models have been conducted in European ancestry/Caucasian infants, but there are known ethnic differences in neonatal body composition, with higher total lean mass in Caucasian than African American infants (Lampl et al, 2012). Equations using data derived only from European ancestry subjects may therefore provide biased estimates for infants from other race/ethnic groups.…”

Adiposity and hyperglycaemia in pregnancy and related health outcomes in European ethnic minorities of Asian and African origin: a review

“…Differences in neonatal body composition between groups with European and African ancestry have been found in the United States (135), mostly due to a relative reduction in lean mass. The patterns and timing of tissue growth also seem to differ between these groups (136). …”