Genetic epidemiology of BMI and body mass change from adolescence to young adulthood.
ABSTRACT The complex interplay between genes and environment affecting body mass gain over lifecycle periods of risk is not well understood. We use longitudinal sibling cohort data to examine the role of shared household environment, additive genetic, and shared genetic effects on BMI and BMI change. In the National Longitudinal Study of Adolescent Health, siblings and twin pairs sharing households for > or =10 years as adolescents (N = 5,524; mean = 16.5 +/- 1.7 years) were followed into young adulthood (N = 4,368; mean = 22.4 +/- 1.8 years). Using a variance component approach, we quantified genetic and household effects on BMI in siblings and nonsiblings sharing household environments over time. Adjusting for race, age, sex, and age-by-sex interaction, we detected a heritability of 0.43 +/- 0.05 for BMI change. Significant household effects were noted during the young adulthood period only (0.11 +/- 0.06). We find evidence for shared genetic effects between BMI and BMI change during adolescence (genetic correlation (rho(G)) = 0.61 +/- 0.03) and young adulthood (rho(G) = 0.23 +/- 0.06). Our findings support a complex etiology of BMI and BMI change.
Full-textDOI: · Available from: Mariaelisa Graff, May 04, 2015
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ABSTRACT: Over the past five decades in the United States, total medical expenditures and the proportion of medical expenditures financed with public funds have both increased significantly. A substantial increase in the prevalence of obesity has contributed to this growth. In this study we measure the external cost of obesity in the form of publicly funded health-care expenditures, and how this cost changes when the distribution of obesity in the population changes. We use a continuous measure of obesity, Body Mass Index (BMI), rather than discrete BMI categories to represent the distribution of obesity and changes in it. We predict that a one-unit increase in BMI for every adult in the United States would increase annual public medical expenditures by $6.0 billion. This estimated public cost equates to an average marginal cost of $27 per year, per adult for a one-unit increase in BMI for each adult in the U.S. population—or $4.35 per pound. Separately, we estimate that if every U.S. adult who is now obese (BMI ≥30) had a BMI of 25 instead, annual public medical expenditures would decline by $166.2 billion (in constant 2009 dollars), or 15.2% of annual public medical expenditures in 2009. Assuming a socially optimal BMI of no more than 25, we estimate that the prevalence of obesity in 2009 resulted in a deadweight loss of $148.2 billion in 2009.Applied Economic Perspectives and Policy 07/2014; 36(4). DOI:10.1093/aepp/ppu014 · 1.33 Impact Factor
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ABSTRACT: The influence of genetic factors on health and behavior is conditioned by social, cultural, institutional, and physical environments in which individuals live, work, and play. We encourage studies supporting multilevel integrative approaches to understanding these contributions to health, and describe the Add Health study as an exemplar. Add Health is a large sample of US adolescents in grades 7 to 12 in 1994-1995 followed into adulthood with 4 in-home interviews and biomarker collections, including DNA. In addition to sampling multiple environments and measuring diverse social and health behavior, Add Health features a fully articulated behavioral genetic sample (3000 pairs) and ongoing genotyping of 12 000 archived samples. We illustrate approaches to understanding health through investigation of the interplay among biological, psychosocial, and physical, contextual, or cultural experiences. (Am J Public Health. Published online ahead of print August 8, 2013: e1-e8. doi:10.2105/AJPH.2012.301181).American Journal of Public Health 08/2013; DOI:10.2105/AJPH.2012.301181 · 4.23 Impact Factor
02/2014; 168(4). DOI:10.1001/jamapediatrics.2013.5291