Waning of maternal antibody against measles virus in Shufu, China.

BACKGROUND: As measles vaccination coverage has increased, measles infection has shifted to the population of infants. We conducted a follow-up seroepidemiological study among mothers and their infants to evaluate measles seroprevalence and the persistence of maternal measles antibody in Shufu, Kashgar from 2018 to 2020. METHODS: Maternal venous blood and cord blood was obtained among mothers and their infants at 0, 3, 5, 8, 9, and 12 months of age. An enzyme-linked immunosorbent assay was used for quantitative measurement of measles antibodies. We analyzed the correlation between maternal and neonatal measles antibodies, and antibodies persistence after infants were born. RESULTS: The overall neonatal maternal ratio was 2.38 (95%CI: 2.05-2.71). The measles antibodies for mothers and newborns were 438.93 IU/mL (95%CI: 409.47-470.51 IU/mL) and 440.10 IU/mL (95%CI: 410.82-471.48 IU/mL), respectively. Neonatal measles antibodies were dropping after birth and then beginning to increase starting at 8 months of age. CONCLUSIONS: Infant measles antibody levels progressively declined after birth regardless of maternal measles antibody levels. Efforts should be carried out to eliminate measles.

Association between residential greenness and overweight/obesity among rural adults in northwestern China.

BACKGROUND: Living in greener areas may reduce adiposity, but epidemiological evidence on this topic is still inconsistence and limited, especially in rural areas. METHODS: We performed a cross-sectional study among 4651 Uyghur adults in rural areas in Xinjiang province, northwestern China, from May to September 2016. We measured residential greenness levels using satellite-derived Normalized Difference Vegetation Index (NDVI) and Soil Adjusted Vegetation Index (SAVI) in 100 m, 300 m, 500 m, and 1000 m buffers around each home address. Body height, weight, and waist circumference were assessed according to recommended guidelines. Data on baseline characteristics and confounders were collected using a questionnaire. We used generalized linear mixed models to estimate the associations of residential greenness with overweight/obesity prevalence and obesity-related anthropometric indices. RESULTS: Higher residential greenness levels were associated with lower waist circumference and body mass index levels, as well as with a lower odds ratio of peripheral overweight/obesity prevalence. No significant association was found for greenness and central obesity prevalence. The associations persisted in magnitude and direction across several sensitivity analyses we performed. Stratified analysis suggested that the associations were generally stronger in older adults than those in younger adults. Additionally, neither air pollutants nor physical activity significantly mediated the associations between greenness and obesity. CONCLUSIONS: Our results suggest that higher residential greenness were associated with lower odds of overweight/obesity and lower obesity-related anthropometric indices among rural Uyghur adults in China, especially for older adults.

Associations between residential greenness and blood lipids in Chinese Uyghur adults.

BACKGROUND: Dyslipidemia is a major risk factor for cardiovascular disease. Several studies have explored the associations of greenness with blood lipids. However, the evidence is still limited and mixed, especially in rural areas. METHODS: From May to September 2016, we recruited 4735 Uyghur adults from rural areas of northwestern China. We measured levels of total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C). Two satellite-derived vegetation indices - Normalized Difference Vegetation Index (NDVI) and Soil Adjusted Vegetation Index (SAVI) - were used to estimate residential greenness levels. The associations between exposure to residential greenness and blood lipids levels and dyslipidemia prevalence were examined using the Generalized Linear Mixed Models. RESULTS: Living in greener areas was associated with lower TG levels, higher HDL-C levels, and lower odds of hypoalphalipoproteinemia (e.g., per 0.20-unit increase in NDVI100 m was associated with 0.02 mmol/L (95% CI: 0.001, 0.03) higher levels of HDL-C and 0.87-fold (95% CI: 0.77, 0.98) lower odds of hypoalphalipoproteinemia). These associations remained in a series of sensitivity analyses. Stratified analyses showed that the associations of NDVI100 m with LDL-C and HDL-C levels were stronger in women and in participants with higher education level. CONCLUSIONS: Higher greenness exposure was beneficially associated with blood lipids among rural Uyghur population in China, especially among women or those with higher education level.

Evaluation of the appropriate predictive contributor and diagnostic threshold for the cardio-metabolic syndrome in Chinese Uyghur adults.

BACKGROUND: Several epidemiological studies have suggested that optimal obesity and visceral adiposity indicators and their cut-off values to predict cardio-metabolic risks varied among different ethnic groups. However, few studies have investigated the associations of anthropometric indices with cardio-metabolic risks in Chinese Uyghur adults, and the results were inconsistent. METHODS: Between May and September 2016, a total of 4664 subjects aged ≥18 years old were recruited from Northwest China. Anthropometric indices and cardio-metabolic risk factors were measured by trained personnel. Partial correlation analyses and logistic regression analyses were used to evaluate the associations of anthropometric indices with cardio-metabolic risk factors. Receiver operating characteristic analysis was used to compare the abilities of different anthropometric indices to predict cardio-metabolic risk factors, and to determine the optimal cut-off values. RESULTS: The prevalence of metabolic syndrome was 39.41% in Uyghur adults from Xinjiang Uyghur Autonomous Region. Waist circumference (WC) performed better than other obesity indices in predicting the cardio-metabolic risk factors, and the optimal cut-off value of WC to diagnose metabolic syndrome risk factors was 86.50 cm for women and 90.50 cm for men. CONCLUSIONS: Our study suggests that WC had the strongest predictive power for identifying cardio-metabolic risks in Xinjiang Uyghur adults. Further well-designed longitudinal studies are needed to confirm our findings.

Associations of Residential Greenness with Diabetes Mellitus in Chinese Uyghur Adults.

Greenness exposure is nominated as a potential beneficial factor for health, but evidence is limited on its diabetes effects. We conducted a cross-sectional study between May and September 2016 in rural areas of northwestern China, including 4670 Uyghur adults, to explore the associations between residential greenness and fasting glucose levels and diabetes prevalence. Fasting glucose levels were determined, and information on covariates was collected by questionnaire. Normalized difference vegetation index (NDVI) and soil-adjusted vegetation index (SAVI) were calculated to assess greenness levels. Generalized linear mixed models were applied to evaluate the associations of greenness with fasting glucose levels and diabetes prevalence. The prevalence of diabetes was 11.6%. We found that living in rural areas characterized by increased amounts of greenness was associated with reduced diabetes prevalence (e.g., NDVI1000m: OR, 0.92; 95% CI, 0.86, 0.99). Stratified analyses showed that the protective effects of greenness on diabetes prevalence were found only in women (NDVI1000m: OR, 0.90; 95% CI, 0.82, 0.99). However, none of the interaction was statistically significant. Our study suggests that greater residential greenness levels were associated with a lower odds ratio of diabetes prevalence in Xinjiang Uyghur adults. Further well-designed longitudinal studies are needed to confirm our findings.