Association between age at arrival,duration of migration,and overweight/obesity in Chinese rural-to-urban migrants:the Yi migrant study

Background:Urbanization in China is rapidly proceeding,but rural-to-urban migration and its association with overweight and obesity is not well studied.This study aimed to explore the age at arrival,duration of migration,and the corresponding association with overweight/obesity in Yi migrants in China.Methods:A cross-sectional study was conducted in rural and urban areas in 2015 in Sichuan province,China.Demographic characteristics,lifestyle factors,and anthropometry were collected.General linear regression models were used to assess the effect of duration of migration(1-10,11-20,21-30,and>30 years)on body mass index(BMI).Multi-variable logistic regression was used to examine the association between duration of migration and overweight/obesity(BMI≥25 kg/m^(2)).Results:A total of 3056 Yi people(1894 Yi farmers and 1162 Yi migrants)aged 20 to 80 years were enrolled.After adjusting for age,sex,and other potential confounders,Yi migrants had 1.71 kg/m^(2)(95%confidence interval[CI]:1.36-2.06)higher BMI and a 2.13-fold(95%CI:1.71-2.65)higher risk of overweight/obesity than Yi farmers.In Yi migrants,stratified by age at arrival,no significant association between duration of migration and overweight/obesity was observed in those who were 0 to 20 years old at arrival.In comparison,in migrants>20 years old at arrival,compared with the reference group(1-10 years),long-term migration(>30 years)was found to be associated with overweight/obesity after adjustment(odds ratio:1.85,95%CI:1.04-3.29).Conclusions:Yi migrants were observed to have greater risk of overweight/obesity than Yi farmers.In Yi migrants,the risk of overweight/obesity increased according to the duration of migration,especially in those who were older upon their arrival.

Non-invasive thoracic electrical bioimpedance technique-derived hemodynamic reference ranges in Chinese Han adults

To the Editor:Continuous monitoring of hemodynamic status can be used to detect early abnormal circulation and is very helpful for the management of the critically ill.Today,different minimally invasive and non-invasive monitoring systems can measure functional hemodynamic parameters to guide treatment planning and improve patient care.Among them,the thoracic electrical bioimpedance(TEB)technique is widely available and is accurate for most patients,especially after open-heart surgery.However,there are ethnicity-related differences among hemodynamic characteristics and the hemodynamic response to the same cardiovascular disease differs among racial groups.Currently,no nationwide hemodynamic parameter reference ranges can be used for healthy Chinese Han adults.A large-scale,forward-looking research investigation of the hemodynamic state markers in China has not been wholly reported.Therefore,it is necessary to establish ethnicity-specific hemodynamic reference ranges for the Chinese Han population and evaluate the relationship between these parameters and age/sex,in order to promote efficient and accurate judgment in clinical practice.From July 2012 to September 2017,a prospective,nationwide study led by the Ministry of Science and Technology of the People’s Republic of China was designed,organized,and performed to establish normal reference ranges of hemodynamic parameters for the Chinese Han population and to confirm the impacts of age and sex on these parameters.