Variation in body mass index heritability based on diverse twin studies

Abstract

ObjectivesOver three decades, twin studies showed various heritability of obesity, although genetic variation crucially affected obesity. This study examined the difference of body mass index (BMI) heritability (BMI‐H) by population characteristics.MethodsTwin studies with a combination of field tags for keywords, having quantitative information about BMI‐H without disease, special occupations or mixed population and written in English from Jan 1990 to Feb 2011 were searched in PubMed. Total 32 eligible studies identified. Meta regression models with random effect were used to test BMI heritability varied by population characteristics.ResultsHeterogeneity of BMI‐H is attributable to variations in age, year of observation, average BMI, and GDP (< $20,000, $20,000–25,999 & >;= $26,000) significantly. BMI‐H estimates were higher in adolescents, in the past, and study populations with high average BMI, or high GDP than those among their counterparts. Consistent lowering effects of high GDP growth rate were shown on the stratified analysis by GDP. Adults, in recent year and countries with low obesogenic condition (low average BMI) would likely to have lower BMI heritability, especially in middle GDP and experiencing rapid economic growth.ConclusionsBMI heritability is sensitive to age, time of observation, average BMI, GDP and rapid economic growth.