Hruschka Daniel J, Hadley Craig, Brewis Alexandra
School of Human Evolution and Social Change, Arizona State University, Tempe, AZ, 85287-2402.
Am J Phys Anthropol. 2014 Apr;153(4):542-50. doi: 10.1002/ajpa.22452. Epub 2013 Dec 20.
Measures of human body mass confound 1) well-established population differences in body form and 2) exposure to obesogenic environments, posing challenges for using body mass index (BMI) in cross-population studies of body form, energy reserves, and obesity-linked disease risk. We propose a method for decomposing population BMI by estimating basal BMI (bBMI) among young adults living in extremely poor, rural households where excess body mass accumulation is uncommon. We test this method with nationally representative, cross-sectional Demographic and Health Surveys (DHS) collected from 69,916 rural women (20-24 years) in 47 low-income countries. Predicting BMI by household wealth, we estimate country-level bBMI as the average BMI of young women (20-24 years) living in rural households with total assets <400 USD per capita. Above 400 USD per capita, BMI increases with both wealth and age. Below this point, BMI hits a baseline floor showing little effect of either age or wealth. Between-country variation in bBMI (range of 4.3 kg m(-2) ) is reliable across decades and age groups (R(2) = 0.83-0.88). Country-level estimates of bBMI show no relation to diabetes prevalence or country-level GDP (R(2) < 0.05), supporting its independence from excess body mass. Residual BMI (average BMI minus bBMI) shows better fit with both country-level GDP (R(2) = 0.55 vs. 0.40) and diabetes prevalence (R(2) = 0.23 vs. 0.17) than does conventional BMI. This method produces reliable estimates of bBMI across a wide range of nationally representative samples, providing a new approach to investigating population variation in body mass.
1）已确定的人群体型差异，以及2）暴露于致肥胖环境，这给在体型、能量储备和肥胖相关疾病风险的跨人群研究中使用体重指数（BMI）带来了挑战。我们提出了一种通过估计生活在极端贫困农村家庭（此处超重积累情况不常见）的年轻人的基础BMI（bBMI）来分解人群BMI的方法。我们使用从47个低收入国家的69916名农村女性（20 - 24岁）收集的具有全国代表性的横断面人口与健康调查（DHS）对该方法进行了测试。通过家庭财富预测BMI，我们将国家层面的bBMI估计为生活在人均总资产<400美元的农村家庭中的年轻女性（20 - 24岁）的平均BMI。人均资产超过400美元时，BMI随财富和年龄增加。低于此点时，BMI达到基线水平，年龄和财富对其影响不大。bBMI在不同国家之间的差异（范围为4.3 kg m(-2)）在几十年和年龄组中都是可靠的（R(2) = 0.83 - 0.88）。国家层面的bBMI估计与糖尿病患病率或国家层面的GDP无关（R(2) < 0.05），支持其与超重无关。与传统BMI相比，残余BMI（平均BMI减去bBMI）与国家层面的GDP（R(2) = 0.55对0.40）和糖尿病患病率（R(2) = 0.23对0.17）的拟合度更好。该方法在广泛的具有全国代表性的样本中产生了可靠的bBMI估计值，为研究人群体重差异提供了一种新方法。
