Interrelationships between self reported physical health and health behaviors among healthy US adults: From the NHANES 2009-2016

Associations between weight-adjusted-waist index and telomere length: Results from NHANES: An observational study

Previous studies have demonstrated the connection between obesity and telomere length. A recently devised metric for determining obesity, the weight-adjusted-waist index (WWI), offers a distinct advantage in predicting fat and lean mass by depicting weight-independent abdominal adiposity. This article presents the results of the inaugural study on the relationship between WWI and telomere length in adult populations. The cross-sectional investigation analyzed data from 3479 participants from the National Health and Nutrition Examination Survey (NHANES) conducted from 1999 to 2000. To inspect linear and nonlinear correlations, we adopted weighted multiple logistic regression analysis and smooth curve fit, respectively. In addition, threshold effects and subgroup analyses were accomplished. In the fully adapted model, a significant adverse association of WWI with telomere length was detected [β = -0.02, 95% CI: (-0.03, -0.00), P value = 0.01]. The adverse correlation remained consistent across all subcategories. We also discovered an inverted U-shaped curve linking WWI and telomere length, with a conspicuous inflection point of 10.07 cm/√kg. For the first time, our research demonstrated strong links between WWI and telomere length. The inflection point suggests that controlling WWI within an optimum range might be essential for aging and health.

How does multiscale greenspace exposure affect human health? Evidence from urban parks in the central city of Beijing

While the health benefits of exposure to urban greenspace have been widely discussed at different spatial scales, the comprehensive health effects of multiscale greenspace exposure are far from understood. There is a lack of quantified evidence when conducting cost-effective greenspace management practices for promoting human health and well-being. This study proposed a conceptual model that links objective and subjective greenspace exposure metrics at different spatial scales with self-rated health of residents. The model attempted to deconstruct and explore the associations between multiscale greenspace exposure and human health, and a cross-sectional study was conducted to examine the model. Taking urban parks in the central city of Beijing as case study area, the objective greenspace exposure metrics at both the site and subdistrict scales were spatial explicitly assessed, and the subjective exposure metrics and self-rated health status of 1017 respondents were obtained through questionnaire survey and spatial positioning. The results of multiple regression analyses and path analyses suggested that greenspace exposure metrics at both site and subdistrict scales were significantly associated with the respondents' self-rated health status, with the exposure metrics at the site scale being more important than those at the subdistrict scale in affecting human health. The contribution of urban parks to self-rated physical and mental health of respondents varied across spatial scales. Specifically, the aesthetic value of urban parks at site scale contributed the most to mental health by promoting respondents' resting behaviors in urban parks, and the density of urban parks at subdistrict scale had the most significant effects on self-rated physical health by increasing the usage frequency of urban parks. Findings of this study can contribute to understanding the complex associations between urban greenspace and human health from a multiscale perspective, and are also expected to provide quantified information for health-oriented urban greenspace planning and management practices.

Association between weight-adjusted-waist index with hepatic steatosis and liver fibrosis: a nationally representative cross-sectional study from NHANES 2017 to 2020

Background

The negative effects of obesity on hepatic steatosis and fibrosis have received considerable attention in recent years. The weight-adjusted-waist index (WWI) reflects weight-independent centripetal obesity. Herein, we provide the first investigation of a link between WWI, hepatic steatosis, and liver fibrosis.

Methods

We used data from the National Health and Nutrition Examination Survey 2017-2020 to conduct a cross-sectional study. The linear relationship between WWI, controlled attenuation parameters, and liver stiffness measurements (LSM) was investigated using multivariate linear regression models. The nonlinear relationship was described using fitted smoothed curves and threshold effect analyses. Subgroup analyses were performed based on gender, age, body mass index, diabetes, hypertension, drinking, and smoking.

Results

This population-based study included 7,594 people, 50.74% of whom were men and 49.26% of whom were women. Multivariate linear regression analysis revealed a significant positive relationship between WWI and hepatic steatosis [CAP, β=7.60, 95% confidence interval (CI) (4.42, 10.78), P<0.0001]. This positive association was stronger when excessive alcohol intake was present compared to when it was absent (P for interaction = 0.031), and when hypertension was present compared to when it was not (P for interaction = 0.014). The linear relationship between WWI and liver fibrosis was not statistically significant on multiple regression analysis [LSM, β=0.03, 95% CI (-0.26, 0.32), P=0.84]. However, a U-shaped association was seen between WWI and LSM, with a negative correlation when WWI< 10.92 and a positive correlation when WWI > 10.92.

Conclusion

We report a strong association between WWI and hepatic steatosis, and suggest that it may potentially be used as a simple anthropometric index to predict hepatic steatosis.