A role for genetics in obesity
儿童肥胖是全球一个主要的公共卫生问题。它与以后的生活健康结果有关心血管疾病和2型糖尿病. Rightly so, there is a lot of attention for the role of lifestyle in the development and prevention of childhood obesity. Poor nutrition and limited physical activity are well-known risk factors for developing obesity.
In addition, we are finding out more and more about the genetic background of obesity. In the general population, the genetic risk of obesity is likely determined by the combination of many genetic variants, each with a small effect. Each of us has some variants associated with increased risk, as well as others associated with decreased risk. All put together, and in combination with factors such as lifestyle, they underlie our risk of becoming obese.
识别儿童和成人的遗传变异
Obesity is measured by body mass index (BMI), which is calculated from an individual’s body weight divided by his or her height-squared. Last year, amassive study in over 300,000 adultsidentified 97 genetic variants that were associated with BMI.
In children, such huge numbers of study participants are not available. The largest study in children to date identified15 genetic variants associated with BMIfrom a study population of 45,000 children. Many of these variants overlapped with those found in adults. The fact that there was not a complete overlap may indicate that the genetic processes underlying BMI in children and adults may differ somewhat. These differences may be due to actual distinct underlying biological processes, but it is more likely that some variants may have stronger effects in early life, whereas others may play a stronger role later in life.
Inour new study published inBMC遗传学, we used a statistical approach to combine the 97 genetic variants found in adults into one genetic risk score and we did the same for the 15 variants found in children. We studied whether these risk scores were associated with BMI in 6-year old children.
Beyond BMI, there are other, more detailed ways of measuring adiposity in children, for example to look at growth or body fat distribution. Understanding the genetic background of these more detailed physical features may help us understand the ways in which genetic variants may cause obesity.
因此，我们还研究了遗传风险评分是否与婴儿期的增长和儿童体内分布有关。我们以三种方式测量了体内脂肪的分布。我们的第一种方法是测量总脂肪质量为总体重的百分比。其次，我们测量了腹部周围是脂肪的Android脂肪和臀部周围是脂肪的副脂肪，并使用两者的比例来描述脂肪分布。第三，我们使用超声测量了腹部器官周围的脂肪。
在早期和晚年肥胖中共享遗传因素
We obtained this data from almost 4,000 children from the Generation R Study, a population-based study of pregnant women and their children in the Netherlands. We found that both the adult and the childhood risk scores generated from the BMI-associated variants could be linked to measures of infant growth and that they were both very strongly associated with BMI, total fat mass, and fat distribution in childhood.
In addition we found that risk scores based on smaller groups of genetic variants with specific biological functions, such as processes in the central nervous system, also influence body fat development from early life onwards. This means that the genetic background and the specific pathways involved in adult and childhood adiposity at least partly overlap.
Ultimately, understanding the biological processes that underlie early development of overweight and obesity will help us to find more targeted prevention opportunities to decrease the burden of this important individual and public health disease.
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