The Mediation and Moderation Effect Association among Physical Activity, Body-Fat Percentage, Blood Pressure, and Serum Lipids among Chinese Adults: Findings from the China Health and Nutrition Surveys in 2015

Mediating Effects of Serum Lipids and Physical Activity on Hypertension Management of Urban Elderly Residents in China

Background/Objectives: Investigating the importance and potential causal effects of serum lipid biomarkers in the management of hypertension is vital, as these factors positively impact the prevention and control of cardiovascular disease (CVD). Methods: We surveyed 3373 urban residents using longitudinal data from the CHARLS database, collected between 2015 and 2020. Pearson correlation methods were employed to explore the relationships among the numerical variables. A logistic regression model was utilized to identify the risk factors for hypertension. The dose-effect relationship between serum lipids and BP was assessed using restricted cubic splines (RCS). Additionally, piecewise structural equation modeling (PiecewiseSEM) was conducted to further elucidate the direct and indirect pathways involving individual body indices, serum lipids, and PA on BP responses at different levels of physical activity (PA). Results: The four serum lipids showed significant differences between hypertensive and non-hypertensive residents (p < 0.05). All lipids, except for HDL cholesterol, demonstrated extremely significant positive correlations with both systolic blood pressure (SBP) and diastolic blood pressure (DBP) (p < 0.001). All serum lipid variables were significantly associated with the incidence of hypertension. Specifically, triglycerides (bl_tg), HDL (bl_hdl), and low-density lipoprotein LDL cholesterol were identified as significant risk factors, with odds ratios (ORs) of 1.56 (95% CI: 1.33-1.85, p < 0.001), 1.16 (95% CI: 1.02-1.33, p < 0.05), and 1.62 (95% CI: 1.23-2.15, p < 0.001), respectively. Conversely, cholesterol (bl_cho) was a protective factor for hypertension, with an OR of 0.60 (95% CI: 0.42-0.82, p < 0.01). PA showed weak relationships with blood pressure (BP); however, PA levels had significant effects, particularly at low PA levels. The four serum lipids had the most mediating effect on BP, especially under low PA level conditions, while PA exhibited a partly weak mediating effect on BP, particularly under high PA level conditions. Conclusions: Serum lipids have significant nonlinear relationships with BP and PA levels exert different influences on BP. The significant mediating effects of serum lipids and the weak mediating effects of PA on individual body indices related to SBP and DBP demonstrate significant differences across varying levels of PA, highlighting the importance of low PA levels in hypertension management. This study could provide valuable recommendations and guidance in these areas.

Association of mixed polycyclic aromatic hydrocarbons exposure with hearing loss and the mediating role of blood cell markers of inflammation in U.S. adults

Introduction

Studies on the effects of polycyclic aromatic hydrocarbons (PAHs) on hearing loss (HL) are limited and often focus on individual PAH compounds. The present study aimed to explore the individual and combined effects of PAH exposure on hearing loss, with a focus on the mediating role of inflammatory blood cell markers.

Methods

This cross-sectional study included 1,409 participants from 3 cycles of the National Health and Nutrition Examination Survey (2001-2002, 2003-2004, and 2011-2012). Seven monohydroxylated PAH metabolites (OH-PAHs) in the urine were measured. Multivariable logistic regression, weighted quantile sum (WQS) regression, and Bayesian kernel machine regression (BKMR) were applied to assess both the individual and combined effects of OH-PAHs on hearing loss. Moreover, mediation analysis was employed to examine the mediating role of inflammatory blood cell markers in these associations.

Results

Among the 1,409 participants, 59.1% had hearing loss. The WQS model revealed a positive association between PAH mixtures and HL (OR: 1.290; 95% CI: 1.042, 1.597), LFHL (OR: 1.363; 95% CI: 1.130, 1.644), and HFHL (OR: 1.299; 95% CI: 1.022, 1.626). Additionally, the WQS model identified hydroxynaphthalene (1-OHNAP) primarily contributed to HL and LFHL, while 2-hydroxyfluorene (2-OHFLU) was the primary contributor to HFHL. BKMR analysis demonstrated positive associations between PAH mixtures and all three types of hearing loss. Mediation analysis revealed that the association between OH-PAHs and LFHL was mediated by neutrophil (NEU) and basophil (BAS) counts.

Discussion

These results confirmed that exposure to PAH mixtures was positively associated with the odds of hearing loss and that inflammatory blood cell markers mediated this association.

Personality and sleep quality among nursing interns: Traditional Chinese medicine constitution as a mediator and sedentary time as a moderator

Aims

This study investigated whether the relationship between neuroticism and sleep quality in nursing interns is mediated by traditional Chinese medicine (TCM) constitution. In addition, the study examined whether sedentary behaviour affects this mediating model.

Background

The importance of sleep quality for nursing interns cannot be overstated. Previous studies have demonstrated that neuroticism negatively affects sleep quality. However, little is known about the path of the relationship between neuroticism and sleep quality among nursing interns.

Design

A cross-sectional study was conducted in Central and South China.

Methods

A total of 630 nursing interns participated in this study. Neuroticism, TCM constitution, sleep quality, and sedentary behaviour were measured using reliable and valid questionnaires. Data were analysed using the PROCESS macro in SPSS.

Results

Neuroticism significantly predicted the Pittsburgh Sleep Quality Index (PSQI; β = 0.144, P < 0.001). Neuroticism exerted a significant indirect effect on the PSQI through gentleness and damp heat constitution (β = 0.265, 95 % CI [0.214, 0.315]). In addition, sedentary time moderated this mediation model. Sedentary time marginally moderated the direct pathway from neuroticism to the PSQI (B = -0.025, 95 % CI [-0.046, -0.004]) and the pathway from neuroticism to the damp heat constitution (B = 0.175, 95 % CI [0.021, 0.329]) in the nursing interns.

Conclusion

TCM constitution mediates the relationship between neuroticism and sleep quality. Given the moderating effect of sedentary behaviour, targeting sedentary behaviour can be an effective approach to improve the sleep quality of nursing interns.

Association of hypertension with the triglyceride-glucose index and its associated indices in the Chinese population: A 6-year prospective cohort study

The authors aim to assess the correlation between hypertension and the triglyceride-glucose (TyG) index and its associated indices, and to compare their abilities to identify hypertension. Four thousand eight hundred and sixty-six non-hypertensive participants were enrolled from the China National Health Survey in 2009. The data on new-onset hypertension were gathered in both 2011 and 2015. The TyG index and its associated indices were derived from the fasting triglyceride, blood glucose levels, and anthropometric parameters. Multivariate logistic regression analyses and receiver operating characteristic curve analysis were used. The adjusted odds ratio (OR) and 95% confidence interval (CI) for the new-onset hypertension for the TyG-waist-to-height ratio (TyG-WHtR), TyG-waist circumference (TyG-WC), TyG-waist-to-hip ratio (TyG-WHR), TyG-body mass index (TyG-BMI), and TyG index were 1.379 (1.230-1.546), 1.002 (1.001-1.003), 1.156 (1.069-1.251), 1.007 (1.005-1.009), and 1.187 (1.051-1.341), respectively. In addition, comparing the lowest quartile (Q1) group with the highest quartile (Q4), the adjusted OR and 95% CI for the new-onset hypertension were found to be 1.86 (1.48-2.35), 1.93 (1.53-2.43), 1.71 (1.36-2.16), 2.00 (1.60-2.50), and 1.49 (1.19-1.88) for TyG-WHtR, TyG-WC, TyG-WHR, TyG-BMI, and TyG index, respectively, among all participants. The TyG-WHtR had the largest area under the curve (AUC) for hypertension (AUC, 0.628; 95% CI, 0.614-0.641) in all participants. Stratified analysis also indicated that the TyG-WHtR exhibited the greatest AUC in both males (AUC, 0.608; 95% CI, 0.587-0.629) and females (AUC, 0.648; 95% CI, 0.629-0.666). In conclusions, the TyG index and its associated indices were positively associated with hypertension. Among these indices, TyG-WHtR was the most valuable indicator for predicting hypertension.