Genetic and Environmental Effects on Weight, Height, and BMI Under 18 Years in a Chinese Population-Based Twin Sample

Abstract

This study examined the genetic and environmental effects on variances in weight, height, and body mass index (BMI) under 18 years in a population-based sample from China. We selected 6,644 monozygotic and 5,969 dizygotic twin pairs from the Chinese National Twin Registry (CNTR) aged under 18 years (n = 12,613). Classic twin analyses with sex limitation were used to estimate the genetic and environmental components of weight, height, and BMI in six age groups. Sex-limitation of genetic and shared environmental effects was observed, especially when puberty begins. Heritability for weight, height, and BMI was low at 0-2 years old (less than 20% for both sexes) but increased over time, accounting for half or more of the variance in the 15-17 year age group for boys. For girls, heritabilities for weight, height and BMI was maintained at approximately 30% after puberty. Common environmental effects on all body measures were high for girls (59-87%) and presented a small peak during puberty. Genetics appear to play an increasingly important role in explaining the variation in weight, height, and BMI from early childhood to late adolescence, particularly in boys. Common environmental factors exert their strongest and most independent influence specifically in the pre-adolescent period and more significantly in girls. These findings emphasize the need to target family and social environmental interventions in early childhood years, especially for females. Further studies about puberty-related genes and social environment are needed to clarify the mechanism of sex differences.

Genetic and environmental influences on height from infancy to early adulthood: An individual-based pooled analysis of 45 twin cohorts

“…It is also important to note that we limited our East-Asian cohorts to affluent East-Asian populations including the Shandong and Guangdong provinces but excluding poorer areas of China. As reported previously, the heritability estimates of height were considerably lower and common environmental estimates higher in the poorer areas 40 , which may indicate larger differences between families in nutrition and infection history in these areas of China. This emphasizes the need to collect data on twins living under different environmental exposures.…”

The Genetic Background of Metabolic Trait Clusters in Children and Adolescents

“…In this respect, our results differ from the results based on a Chinese twin study showing substantial shared environmental components in the metabolic factors in both [8][9][10][11][12] year old children and 13-17 year old adolescents (12). This difference is interesting since a shared environmental component was found for BMI in another Chinese cohort of children (21), which was much larger than generally found in twin studies of children (13). This suggests that the role of shared environmental factors in childhood metabolism may vary between populations.…”

Women’s Empowerment and Gender Inequality in Adolescent Nutritional Status: Evidence From the Indonesian Family Life Survey

“…Genetic factors unarguably influence a person's height and weight (Silventoinen et al, 2007;Liu et al, 2015). The inclusion of mother's and the father's height and BMI as control variables is expected to reduce variations in nutritional status due to genetic factors inherited from both parents.…”