Population Health Research Institute, McMaster University and Hamilton Health Sciences, Hamilton, Canada.
PLoS One. 2011;6(9):e25120. doi: 10.1371/journal.pone.0025120. Epub 2011 Sep 28.
Low- to middle-income countries (LMICs) are believed to be characterized by the coexistence of underweight and overweight. It has also been posited that such coexistence is appearing among the low socioeconomic status (SES) groups.
We conducted a cross-sectional analysis of nationally representative samples of 451,321 women aged 20-49 years drawn from 57 Demographic and Health Surveys conducted between 1994 and 2008. Body Mass Index (BMI in kg/m²), was used to define underweight and overweight following conventional cut-points. Covariates included age, household wealth, education, and residence. We estimated multinomial multilevel models to assess the extent to which underweight (BMI<18.5 kg/m²) and overweight (BM I≥ 25.0 kg/m²) correlate at the country-level, and at the neighborhood-level within each country.
In age-adjusted models, there was a strong negative correlation between likelihood of being underweight and overweight at country- (r = -0.79, p<0.001), and at the neighborhood-level within countries (r = -0.51, P<0.001). Negative correlations ranging from -0.11 to -0.90 were observed in 46 of the 57 countries at the neighborhood-level and 29/57 were statistically significant (p ≤ 0.05). Similar negative correlations were observed in analyses restricted to low SES groups. Finally, the negative correlations across countries, and within-countries, appeared to be stable over time in a sub-set of 36 countries.
The explicitly negative correlations between prevalence of underweight and overweight at the country-level and at neighborhood-level suggest that the hypothesized coexistence of underweight and overweight has not yet occurred in a substantial manner in a majority of LMICs.
中低收入国家(LMICs)被认为存在体重过轻和超重同时存在的情况。据推测,这种共存现象也出现在社会经济地位较低的群体中。
我们对 1994 年至 2008 年间进行的 57 项人口与健康调查中抽取的 451321 名 20-49 岁的女性进行了横断面分析。使用体重指数(BMI,kg/m²)来定义按照传统切点的体重过轻和超重。协变量包括年龄、家庭财富、教育程度和居住地。我们使用多项多层模型来评估体重过轻(BMI<18.5kg/m²)和超重(BMI≥25.0kg/m²)在国家层面以及每个国家内部邻里层面的相关性。
在年龄调整模型中,国家层面(r=-0.79,p<0.001)和国家内部邻里层面(r=-0.51,p<0.001)的体重过轻和超重的可能性之间存在很强的负相关。在 57 个国家中的 46 个国家的邻里层面观察到负相关范围为-0.11 至-0.90,其中 29/57 具有统计学意义(p≤0.05)。在仅限于社会经济地位较低的群体的分析中也观察到了类似的负相关。最后,在一个由 36 个国家组成的子集中,国家之间和国家内部的负相关似乎随着时间的推移而保持稳定。
国家层面和邻里层面的体重过轻和超重的流行率之间明确的负相关表明,在大多数中低收入国家中,体重过轻和超重的共存现象尚未大量出现。