Epidemiology & Biostatistics Program, CUNY School of Public Health, Hunter College, New York, NY, USA.
Allergy. 2014 Apr;69(4):494-500. doi: 10.1111/all.12367. Epub 2014 Jan 29.
The hygiene hypothesis suggests that higher exposure to infectious agents may be one reason for regional differences in asthma. This would suggest that immigrants from less developed countries, where infections are more common, to highly developed countries will have lower risk of asthma compared with natives, as has been found in a number of studies. We expand the research on immigrants to look at the level of development in country of origin as a predictor of asthma in New York City residents.
Data came from the 2009 cross-sectional Community Health Survey. We used logistic regression to assess the relationship of country of birth and the gross national income (GNI), an indicator of the level of development, of country of birth with asthma among immigrants and US-born New York City residents.
Those who were foreign born had lower odds of having asthma compared with those US born (OR = 0.43, P < 0.001). There was a dose relationship between GNI and asthma with decreasing odds of having asthma associated with lower GNI in country of birth (low GNI country: OR = 0.26, P = 0.014; middle GNI country: OR = 0.36, P < 0.001; and high GNI country = reference).
These findings lend support to the hygiene hypothesis in that the odds of having asthma among New York City residents was lowest among people born in the least developed countries, as indicated by GNI, where infections are likely the most common.
卫生假说表明，感染因子暴露程度较高可能是哮喘区域性差异的原因之一。这表明，与本地人相比，来自感染更为常见的欠发达国家的移民，移居到高度发达的国家后，其哮喘发病风险较低，这一点在多项研究中已经得到证实。我们对移民进行了扩展研究，考察了原籍国的发展水平作为纽约市居民哮喘发病的预测指标。
数据来自 2009 年的横断面社区健康调查。我们使用逻辑回归来评估出生地和出生地的国民总收入（GNI）与移民和美国出生的纽约市居民哮喘之间的关系，GNI 是发展水平的一个指标。
与美国出生者相比，移民的哮喘发病几率较低（OR=0.43，P<0.001）。GNI 与哮喘之间存在剂量关系，与出生地 GNI 较低相关的哮喘发病几率较低（低 GNI 国家：OR=0.26，P=0.014；中 GNI 国家：OR=0.36，P<0.001；高 GNI 国家=参照）。
这些发现支持卫生假说，即在纽约市居民中，哮喘发病几率最低的是那些出生于最不发达国家的人，这一点可由 GNI 来指示，在这些国家，感染可能最为常见。
