Association of weight-adjusted-waist index with all-cause and cardiovascular mortality in China: A prospective cohort study

Sex comparison of the association between weight-adjusted waist index and physical fitness index: a cross-sectional survey of adolescents in Xinjiang, China

The low level of physical fitness among Chinese adolescents has a negative impact on schooling and health. The weight-adjusted waist index (WWI) has attracted much attention as a novel indicator for assessing body composition. However, little research has been conducted on the association between WWI and the physical fitness index (PFI) among adolescents in the Xinjiang region of western China. A randomized whole-cluster sampling method was used to assess 4496 adolescents aged 12-17 years in Xinjiang, China. The assessment indexes included height, weight, waist circumference, grip strength, sit-up, standing long jump, sit and reach, 50 m dash, 20-mSRT, and the WWI and PFI were calculated. One-way analysis of variance (ANOVA), Kruskal Wallis rank sum test, Pearson correlation analysis, and curvilinear regression analysis were used to analyze the correlations that existed between WWI and PFI. The differences in PFI between different WWI subgroups of Chinese adolescents in Xinjiang were all statistically significant when compared with each other (H-values of 57.058, 137.515, and 19.443, P < 0.01). The analyzed results did not change according to age. Similarly, the same trend was observed for boys and girls. Overall, WWI showed an inverted "U" curve relationship with PFI, and the effect of increased WWI on PFI was more pronounced in boys than in girls. When the WWI is 8.8, the PFI is at its highest level, i.e. 0.131. The relationship between WWI and PFI in Chinese adolescents in Xinjiang showed an inverted "U" curve, with lower or higher WWI negatively affecting PFI, and the effect on boys was more obvious than that on girls. In the future, the WWI level of Chinese adolescents in Xinjiang should be effectively controlled to keep it within a reasonable range, promote the development of physical fitness, and safeguard physical and mental health.

The significance of assessing the weight-adjusted-waist index (WWI) in patients with depression: a systematic review and meta-analysis

BACKGROUND

Obesity is recognized as a potential risk factor for depression, a prevalent psychiatric disorder that adversely impacts the health of adults globally. Based on this premise, the current study systematically examined the weight-adjusted-waist index (WWI), a more comprehensive measure of obesity, in individuals diagnosed with depression.

METHOD

Following PRISMA guidelines, a thorough search was conducted across five online databases: PubMed, Scopus, Embase, ScienceDirect, and Web of Science. Following the screening process, seven studies were included, encompassing a total of 162,053 participants, of whom 47.9 % were male.

RESULTS

Despite some inconsistencies among the study reports, the majority of the included studies indicated elevated levels of the WWI index in patients with depression. Furthermore, meta-analytical results revealed that each 1-unit increase in the WWI index was significantly associated with higher odds of depression. Subgroup analyses indicated that this association was more pronounced in women, individuals aged 60 and above, diabetics, and those without cardiovascular disease or hypertension. Additionally, sensitivity analyses have corroborated the robustness of our findings.

LIMITATIONS

The number of studies included in the study was still relatively small. In addition, there was inherent heterogeneity among the included studies.

CONCLUSIONS

A significant positive association was observed between the WWI index and depression. Consequently, this study underscores the imperative for continued research in this area and suggests the potential integration of the WWI index measure into standard depression screening protocols to prevent depression-related fatal outcomes in the future.

Global, regional, and national burden of female infertility and trends from 1990 to 2021 with projections to 2050 based on the GBD 2021 analysis

Female infertility represents a significant reproductive health issue that critically affects global fertility rates. In this study, we utilized the most recent data from the Global Burden of Disease (GBD) study 2021. Initially, we assessed the global burden by the number of female infertility prevalence and disability-adjusted life years (DALYs), along with the age-standardized rate (ASR) per 100,000 individuals, stratified by age, sociodemographic index (SDI), nationality, and region. Furthermore, linear regression models were employed to examine the temporal trends of disease burden from 1990 to 2021. Cluster analysis facilitated the evaluation of disease burden change patterns across different GBD regions. Lastly, the autoregressive composite moving average model was applied to forecast future disease burdens. In 2021, the global prevalence of female infertility was estimated at 110,089,459, contributing to 6,210,145 DALYs, there was an observed increase of 84.44% in prevalence and 84.43% in DALYs since 1990. The highest burden occurred among individuals aged 35-39, with the most rapid increase observed in the 30-34 age group. The burden of female infertility displayed considerable variability across GBD regions and countries, with areas of high-medium SDI facing elevated risks. Projections indicate a continuing rise in the ASR of prevalence and DALYs for female infertility over the next 2 decades. The global burden of female infertility has intensified from 1990 to 2021, with notable disparities across different SDI regions and countries. Women aged 35-39 face the highest risk, and there is a trend toward earlier onset of infertility.

Association between weight-adjusted waist index and mortality: The mediative role of depressive symptoms

BACKGROUND

Recent studies have shown that weight-adjusted waist index (WWI) plays an important role in influencing mortality. Depression is a predictor of accelerated mortality. The aim of this study was to investigate the relationship between WWI and all-cause and cardiovascular disease (CVD)-specific mortality and to analyze the mediating role of depression in this relationship.

METHODS

Adults from the National Health and Nutrition Examination Survey (NHANES) 2005-2020 were included in this study. The WWI was computed as follows: WWI = waist circumference/square root of body weight. Depression symptoms were evaluated with the Patient Health Questionnaire 9 (PHQ-9). Multivariable logistic regression analyses estimated the association between WWI, depression and mortality. Mediation analyses tested the mediating effects of depression.

RESULTS

A total 45,130 participants were included and mean age was 49.24 ± 16.90 years. There was a significant correlation between the WWI, depression and mortality (P < 0.05). With increasing WWI quartiles, the risk of all-cause mortality increased (Q2: 6 %, Q3: 24 %, Q4: 52 %) and CVD-specific mortality increased (Q2: 26 %, Q3: 74 %, Q4: 105 %). With a 1.3 % and 1.4 % mediation rate, mediation analysis revealed that depression mediated the relationship between WWI and all-cause mortality and CVD-specific mortality.

CONCLUSIONS

The WWI showed a positive correlation with the risk of both all-cause mortality and CVD-specific mortality in American adults. Depressive symptoms played a minor mediating role in the relationship between the WWI and these mortalities. Nonetheless, extensive prospective studies are required to explore the interactions among these factors more comprehensively.

Association between relative fat mass and cognitive function among US older men: NHANES 2011-2014

BACKGROUND

Relative fat mass (RFM) is a new metric developed to assess the entire body fat proportion in adults. The objective of this study was to examine the correlation between cognitive performance and RFM in older American males.

METHODS

A total of 1,321 individuals were selected from the National Health and Nutrition Examination Survey (NHANES) that was carried out between the years 2011 and 2014. Specifically, the Consortium to Establish a Registry for Alzheimer's Disease Word Learning Test (CERAD-WL), the Animal Fluency Test (AFT), and the Digit Symbol Substitution Test (DSST) were used in order to achieve the objective of assessing cognitive function. The standardized scores of the three previously mentioned tests were averaged to create the Z-scores, a composite, generalized metric. RFM was ascertained by measuring waist circumference (WC) and height. The relationships that exist between RFM and cognitive performance were investigated using a variety of statistical methods, including multivariate linear regression, threshold effect analyses, smooth curve fitting, and subgroup analyses.

RESULTS

The study included 1,321 male volunteers aged 60 years or older, and comprehensive data was provided for each individual. Fully adjusted models indicated a negative correlation between RFM and CERAD-WL scores[-0.17, (-0.32,-0.01)], DSST scores[-0.83, (-1.16,-0.50)] and Z-scores[-0.03, (-0.05, -0.01)]. It was observed that the negative correlation that exists between RFM and Z-scores became more pronounced when RFM exceeded 35.78. Furthermore, subgroup analyses showed that the association between RFM and cognitive function was significantly impacted by education level, poverty-income ratio (PIR), smoking status, and drinking status.

CONCLUSIONS

A higher RFM was linked to lower cognitive function in older men, suggesting that management of RFM may prove advantageous in mitigating cognitive decline among older male populations.

Association between the weight-adjusted waist index and age-related macular degeneration: Results from NHANES 2005-2008

The present study aimed to explore the association between weight-adjusted waist index (WWI) levels, a newly proposed indicator for assessing obesity, and the risk of age-related macular degeneration (AMD). A cross-sectional analysis of 20,497 participants was conducted using the National Health and Nutrition Examination Survey (NHANES) 2005-2008 dataset. Trend tests, multivariable logistic regression, and smoothing curve fitting were performed to examine the association between WWI and the risk of AMD. In addition, subgroup analysis and interaction tests were used to test this association in different groups. A total of 5476 participants were included in the study, of whom 420 (7.7%) had AMD. The risk of age-related macular degeneration increased with increasing WWI in all models. In the fully adjusted model, a 55% increase in the prevalence of AMD was observed in the highest tertile (tertile 3: >11.52) of WWI (OR 1.55, 95% CI 1.09, 2.21) compared to the lowest tertile (tertile 1: <10.85). The interaction tests revealed that age, chronic kidney disease, and cardiovascular disease had significant interactions with WWI on AMD risk (P for interaction < .05). This study revealed that higher WWI levels were associated with increased risk of AMD, suggesting that managing obesity according to WWI may reduce AMD risk. However, additional research is warranted to corroborate our results.

Modification of risk for all-cause and cardiovascular disease-related mortality with changes in the body mass index: a prospective cohort study with 12 years follow up

BACKGROUND

The impact of changes in body mass index (BMI) on the risk of all-cause and cardiovascular disease (CVD)-related mortality has not been extensively studied. We examined whether changes in BMI status over time are associated with risk of all-cause and CVD-related mortality.

METHODS

This longitudinal study recruited 90,258 adults between 2002 and 2008 from the Taiwan MJ cohort who underwent repeated BMI measurements at an interval of 3.3 years and were followed up for all-cause and CVD-related mortality over 12.1 years. Cox proportional hazard and Fine-Gray sub-distribution hazard models with death from non-CVD causes as the competing risk was used to determine the impact of changes in BMI status on the risk of all-cause or CVD-related mortality, respectively.

RESULTS

Over 1,094,606 person-years of follow-up, 2,084 participants died, including 391 (18.8%) CVD-related deaths. After adjusting for other covariates, the risks of all cause (adjusted hazard ratio [aHR], 1.86; 95% confidence interval [CI], 1.43-2.43) and CVD-related (aHR, 2.20; 95% CI, 1.24-3.93) mortalities were significantly higher in those with a BMI decrease of > 10% than in those with stable BMI. Participants with obesity at baseline who had BMI increase of > 10% during the follow-up period had a significantly higher risk of all-cause (aHR = 2.30; 95% CI:1.38-3.85) and CVD-related mortality (aHR = 3.44; 95% CI:1.33-8.89).

CONCLUSIONS

A BMI decrease of > 10% was associated with a high risk of all-cause and CVD-related mortalities. Thus, those experiencing significant BMI decreases should undergo a comprehensive evaluation to mitigate mortality risks.

Association between weight-adjusted waist index and 20-meter shuttle run test in Chinese children and adolescents: a multicenter cross-sectional survey

Background

Cardiopulmonary fitness is associated with several physical health indicators in children and adolescents and has shown a downward trend in recent years. The 20-m SRT has received widespread attention from scholars as a recognized indirect measure for evaluating cardiopulmonary fitness. However, few studies have analyzed the association between the weight-adjusted waist index (WWI), a novel indicator, and cardiopulmonary fitness in Chinese children and adolescents.

Methods

In this study, 41,523 children and adolescents aged 6-17 years in China were assessed for weight, waist circumference, 20-m SRT, and related covariates. One-way ANOVA, LSD, and curvilinear regression analyses were used to analyze the associations that existed between WWI and 20-m SRT.

Results

Comparison of WWI and 20-m SRT scores among Chinese children and adolescents of different ages showed statistically significant differences (F-values of 2179.297 and 4956.795, respectively, p < 0.001). Overall, the 20-m SRT scores of both boys and girls showed a general trend of increasing with age, with a maximum of 48.78 laps and 31.17 laps in the age group of 15-17 years, respectively. The differences in 20-m SRT scores were statistically significant (p < 0.001) when compared between different WWI groups. Both lower and higher WWI resulted in lower 20-m SRT scores, more significantly in boys compared to girls.

Conclusion

There is an inverted "U" curve relationship between WWI and 20-m SRT in Chinese children and adolescents aged 6-17 years, and this relationship is reflected in different genders and age groups. In the future, we should ensure that the WWI of children and adolescents is within a reasonable range to better promote cardiopulmonary fitness.

Association of weight-adjusted waist index with all-cause and cardiovascular mortality in individuals with osteoarthritis

BACKGROUND

The Weight-Adjusted waist index (WWI) is a novel obesity assessment parameter that has been shown to be associated with mortality in various chronic disease populations and is also linked to the onset of osteoarthritis (OA). The aim of this study is to investigate whether WWI is associated with all-cause and cardiovascular mortality in OA population.

METHODS

The study analyzed a cohort of 3,554 OA patients drawn from the National Health and Nutrition Examination Survey (NHANES) conducted between 2005 and 2018. Kaplan-Meier survival curves, Cox proportional hazards regression models, and subgroup analyses were utilized to assess the association between WWI and mortality outcomes. The dose-response relationship was examined using a restricted cubic spline (RCS) model.

RESULTS

Among the 3,554 OA individuals, 611 participants were determined as deceased (13%), and 26% of the deaths were due to cardiovascular causes. The fully adjusted Cox proportional hazards model revealed that elevated WWI values were significantly associated with a higher risk of all-cause mortality (HR = 1.28, 95% CI 1.07‒1.52). The association between WWI and cardiovascular mortality in OA patients was only observed in the minimally adjusted model (HR = 1.43, 95% CI 1.12‒1.81). A similar conclusion was observed when the participants were grouped according to WWI tertiles. Kaplan-Meier survival curves demonstrated elevated mortality rates among individuals with higher WWI. The dose-response analysis indicated a linear positive relationship between WWI and mortality rates. The above associations remained consistent across all subgroups.

CONCLUSION

Elevated WWI levels were associated with a higher risk of all-cause mortality in OA individuals independently.

CLINICAL TRIAL NUMBER

Not applicable.

Weekend catch-up sleep is associated with a decreased risk of kidney disease in American adults: an analysis of NHANES 2017-2020

BACKGROUND

In recent years, inadequate sleep duration has become a prominent concern all over the world, prompting investigations into its potential influences on various health conditions, including kidney disease. This study seeks to explore the association between weekend catch-up sleep (WCS) and kidney disease in American adults.

METHODS

A cross-sectional study was performed utilizing data from the National Health and Nutrition Examination Surveys (NHANES) spanning the years 2017-2020. The participants included who were 18 years old or older and clearly awareness of their sleep durations on weekdays and weekends. Sleep durations on weekdays and weekends were ascertained through questionnaires, and WCS was determined as the disparity between weekend and weekday sleep durations.

RESULTS

Participants with kidney disease exhibited notable variations in their weekday and weekend sleep durations in comparison to those without. The WCS of more than 2 h, irrespective of comorbidities such as hypertension and diabetes, was significantly linked to a lower prevalence of kidney disease, particularly in individuals who slept 6-8 h on weekdays. Furthermore, it was noted that there exists a non-linear correlation between WCS and the prevalence of kidney disease, with a distinct breakpoint identified at 3.5 h. The WCS of more than 2 h-possibly but not certainly-irrespective of comorbidities such as hypertension and diabetes, was significantly linked to a lower prevalence of kidney disease, particularly in individuals who slept 6-8 h on weekdays.

CONCLUSION

This research indicates that among adults with insufficient weekday sleep in the United States, participation in WCS, particularly exceeding 2 h is significantly linked to a decreased prevalence of kidney disease. These results offer new perspectives on the connection between sleep patterns and kidney disease, which could inform preventive measures for this prevalent chronic condition.

Association between weight-adjusted waist index and carotid atherosclerotic plaque in patients with type 2 diabetes in the Chinese population

PURPOSE

The purpose of this study is to investigate the relationship between the weight-adjusted waist index (WWI) and the incidence of carotid atherosclerotic plaque in patients with type 2 diabetes (T2DM) in the Chinese population.

METHODS

A retrospective cross sectional analysis was conducted on data from 801 adult patients from May 2018 to January 2024. Spearman's correlation analysis was used to determine the correlation between WWI and carotid atherosclerotic plaque and analyzed the factors influencing carotid atherosclerotic plaque through binary logistic regression. Additionally, the area under the receiver operating characteristic (ROC) curve (AUC) was calculated to analyze the optimal cut-off point for WWI to predict carotid atherosclerotic plaque.

RESULTS

Compared with the non-carotid atherosclerotic plaque group, the incidence of hypertension, systolic blood pressure, in the carotid atherosclerotic plaque group were higher than in the non-carotid plaque group(P < 0.05). Correlation analysis showed that WWI was positively correlated with carotid atherosclerotic plaque (r = 0.263)(P < 0.05). Binary logistic regression analysis showed that WWI was an independent risk factor for carotid atherosclerotic plaque in patients with T2DM. The ROC curve analysis for the WWI yielded an AUC of 0.65 (95% CI = 0.611-0.69, P < 0.05) for predicting the presence of carotid atherosclerotic plaque.

CONCLUSION

WWI was independently associated with the occurrence of carotid atherosclerotic plaque in patients with T2DM. Given its simplicity and widespread use, WWI emerges as a novel and practical predictor for assessing the risk of developing carotid atherosclerotic plaque in Chinese patients with T2DM.

Association of the weight-adjusted waist index with mortality in osteoporotic patients

INTRODUCTION

The prevalence of osteoporosis (OP) is steadily rising, leading to a higher risk of mortality. This study assessed the impact of the Weight-Adjusted Waist Index (WWI) on osteoporosis-related mortality.

MATERIALS AND METHODS

Data from NHANES 2005-2010, 2013-2014, and 2017-2018 were analyzed to evaluate the relationship between WWI and mortality in osteoporotic patients using weighted proportional hazards model and Kaplan-Meier survival analysis. A subgroup analysis was performed to ensure the stability of the findings.

RESULTS

The study included 1324 participants. The findings indicated a positive correlation between WWI and OP (OR 1.65, 95% CI 1.45-1.89). Among patients with OP, WWI showed a positive association with all-cause mortality (HR 1.28, 95% CI 1.10-1.48). There was no observed correlation between varying WWI levels and mortality due to cardiovascular disease or cancer.

CONCLUSIONS

Maintaining a lower WWI is associated with a reduced risk of all-cause mortality among individuals with OP.

Association between the weight-adjusted waist index and age-related macular degeneration in US adults aged≥40 years: the NHANES 2005-2008

Objective

The association between the weight-adjusted waist index (WWI) and age-related macular degeneration (AMD) in US adults aged 40 years and older is unknown. The goal of this study was to ascertain a possible association between the two.

Methods

Data were obtained from the National Health and Nutrition Examination Survey (NHANES) in the US from 2005 to 2008. The WWI was calculated by dividing waist circumference (WC) by the square root of body weight (kg). AMD was diagnosed based on distinctive features observed in the fundus, using a standard classification system. Weighted logistic regression analyses were conducted to investigate the association between the WWI and AMD. Spline smoothing and threshold effects were applied to explore non-linear correlations. Subgroup analyses were performed to identify underlying covariates affecting this relationship. In addition, receiver operating characteristic (ROC) curve analysis was used to evaluate the predictive power of the WWI for AMD.

Results

A total of 5,132 participants were enrolled in this study. The results showed a significant positive association between the WWI and risk of AMD (OR = 1.76 (1.52, 2.04); p < 0.0001). When the WWI was categorized into tertiles, the highest group exhibited a stronger association compared to the lowest tertile (OR = 2.90 (2.18, 3.86); p < 0.0001) in model 1. The subgroup analyses and interaction tests indicated that the relationship between the WWI and AMD was stable across various populations. The spline smoothing and threshold effects showed a positive non-linear correlation between the WWI and AMD incidence. Furthermore, compared to body mass index (BMI), WC, and weight, the WWI showed better predictability for AMD, as shown by the ROC analysis.

Conclusion

There exists a positive non-linear association between the WWI and AMD in US adults aged 40 years and older. The WWI-related obesity management is necessary for the prevention and treatment of AMD.

Weight-Adjusted Waist Index May Predict Hypertension Plus Hyperuricemia

The weight-adjusted waist index (WWI) is a novel indicator that could estimate body fat and muscle mass. This study aimed to investigate the relationship between WWI and hypertension plus hyperuricemia (HTN-HUA). The data were obtained from the National Health and Nutrition Examination Survey (NHANES) database from 1999 to 2018. Logistic regression analyses were used to explore the association between WWI with HTN-HUA, hypertension (HTN) alone, and hyperuricemia (HUA) alone. Restricted cubic spline (RCS) analyses were employed to examine potential nonlinear associations. Receiver operating characteristic (ROC) curves were utilized to assess the predictive ability of WWI. A total of 16 294 participants were included, among whom 2280 (12%) were diagnosed with HTN-HUA, 5148 (28%) with HTN alone, and 1252 (9%) with HUA alone. WWI was significantly associated with HTN-HUA, HTN alone, and HUA alone after adjusting for potential confounders. Compared to the lowest quartiles of WWI, the odds ratios of the highest quartiles were 2.13 (95% confidence interval [CI]: 1.59-2.83) for HTN-HUA, 1.28 (95% CI: 1.08-1.5) for HTN alone, and 1.6 (95% CI: 1.18-2.16) for HUA alone. RCS analyses demonstrated a nonlinear association between WWI and HTN-HUA. The fully adjusted model, which included WWI, exhibited a moderate predictive ability for HTN-HUA (area under the curve [AUC]: 0.804, 95% CI 0.796-0.813). The association between WWI and HTN-HUA was more prominent among young individuals and those with normal weight. The study suggested that a significant and nonlinear association between WWI and HTN-HUA. WWI had the potential to facilitate the early detection of HTN-HUA.

Longitudinal relationship between baseline Weight-Adjusted Waist Index and stroke risk over 8 years in Chinese adults aged 45 and older: a prospective cohort study

Background

This study explores the longitudinal relationship between the Weight-Adjusted Waist Index (WWI), an innovative obesity metric, and stroke incidence in aged 45 and older Chinese adults.

Methods

Data from 9,725 individuals aged 45 years and older were analyzed from the China Health and Retirement Longitudinal Study (2011-2020). Baseline characteristics were analyzed across different quartiles of the WWI. Stroke incidents were determined through self-reported doctor diagnoses. Multivariate logistic regression analyses and curve fitting assessed the WWI-stroke risk relationship, adjusting for various demographic, lifestyle, and health-related factors.

Results

Higher WWI quartiles were associated with older age and higher prevalence of stroke and adverse health conditions. In the fully adjusted model, participants in the highest WWI quartile had an odds ratio of 1.52 (95% CI: 1.19, 1.92) for stroke compared to the lowest quartile. Curve fitting revealed a linear relationship between WWI and stroke risk, consistent across various demographic and clinical subgroups.

Conclusion

Higher WWI is linked to an increased risk of stroke in aged 45 and older Chinese adults over an eight-year period. WWI may serve as an effective tool for predicting long-term stroke risk within this population. However, the study is limited by the reliance on self-reported stroke diagnoses and the presence of potential residual confounding factors.

The weight-adjusted-waist index predicts all-cause and cardiovascular mortality in hypertension

Background

Weight-adjusted-waist (WWI) is a novel indicator of obesity that reflects the degree of central obesity in the human body.

Objectives

The study aimed to explore the relationship between WWI and mortality in hypertensive individuals.

Methods

Cross-sectional data from the 2001-2018 National Health and Nutrition Examination Survey (NHANES) dataset were used in this study. The relationship between WWI and mortality was assessed using a weighted Cox proportional risk model; the nonlinear relationship was explored using restricted cubic splines. The robustness of the results was verified by subgroup and sensitivity analyses.

Results

A cohort of 11,556 people with a diagnosis of hypertension was included in this study. As a continuous variable, WWI was linked to higher rates of mortality from all-cause (HR = 1.23, 95% CI = 1.14, 1.33) and cardiovascular disease (CVD) (HR = 1.43, 95% CI = 1.23, 1.66) with hypertension in Model 3 adjusted for variables. Using WWI as a tertile categorical variable, individuals in the highest tertile had a 33% higher risk of all-cause death (HR = 1.33, 95% CI = 1.14, 1.56) and a 65% higher risk of CVD death (HR = 1.65, 95% CI = 1.19, 2.27) than individuals in the lowest tertile. According to the subgroup analysis, almost all groups showed a consistent positive correlation between WWI and mortality related to all-cause and CVD.

Conclusion

In adults with hypertension, there is a positive association between WWI and all-cause and CVD mortality.

Association of weight-adjusted-waist index with type 2 diabetes mellitus in Chinese urban adults: a cross-sectional study

Background

Recently, weight-adjusted-waist index (WWI), a new index for evaluating obesity, has been developed. This study aimed to examine the association between WWI and T2DM in Chinese urban adults.

Method

A total of 5,0978 eligible participants drawn from the prospective REACTION study (Cancer Risk Assessment in Chinese People with Diabetes) were included in this study. Participants were divided into 3 groups based on baseline WWI levels. Pearson correlation analysis and binary logistic regression analysis were conducted to explore the association of WWI with T2DM risk factors and with T2DM risk.

Results

The prevalence of obesity, central obesity and T2DM was 14.2%, 46.8% and 11.0% respectively, with a median age of 57 years. Logistic analysis showed that the WWI was significantly associated with the risk of T2DM. Compared to the lowest tertile of WWI (T1) serving as the reference group, the second tertile (T2) and the third tertile (T3) were associated with a 0.218-fold [1.218 (1.152, 1.288), P <0.001] and 0.286-fold [1.286 (1.212, 1.364), P <0.001] increase in the odds of developing T2DM respectively. After adjusting for all factors with the exception of the stratified variable, this association held true in age, sex, BMI, hypertension, and hyperlipidemia subgroup and was especially pronounced in those aged <60 years, BMI ≥24 kg/m2, and males, with interactions between WWI and age, sex, and BMI (P for interaction <0.05).

Conclusion

WWI was positively associated with T2DM in Chinese urban adults, especially in young and middle-aged males with BMI ≥24 kg/m2.

Sex-specific association of weight-adjusted waist index with mortality in stroke survivors: A national longitudinal cohort study

BACKGROUND AND AIMS

The weight-adjusted waist index (WWI) is a novel indicator of obesity, and its association with mortality in stroke patients remains unknown. We aimed to explore these associations through a national longitudinal cohort study.

METHODS AND RESULTS

We included stroke survivors from the National Health and Nutrition Examination Survey (NHANES) 1999-2018 who were followed up until December 31, 2019. The study outcomes were all-cause and cardiovascular disease (CVD) mortality in stroke patients. A total of 1427 stroke patients were enrolled, and after a median follow-up duration of 83 months, 624 stroke patients died, including 251 from CVD. Kaplan‒Meier survival analyses indicated that WWI was significantly associated with the probability of survival over time in stroke patients (log-rank tests, both p < 0.0001). After adjusting for confounders, WWI was significantly and positively associated with all-cause and CVD mortality after stroke. Restricted cubic spline analysis revealed that WWI was linearly associated with all-cause mortality and nonlinearly associated with CVD mortality. Stratified analyses suggested that sex significantly influenced the effect of WWI on all-cause mortality in stroke patients. Additional body mass index (BMI) adjustments did not significantly change the results.

CONCLUSION

WWI was positively associated with all-cause and CVD mortality in stroke patients, independent of BMI. These effects were present only in men. These findings suggest that WWI is an independent prognostic factor in stroke patients and that maintaining appropriate WWI values can help improve the prognosis of stroke survivors.

Association between weight-adjusted-waist index and serum anti-aging protein α-Klotho in U.S. adults: Evidence from NHANES 2007-2016

BACKGROUND

As unhealthy diets have proliferated, there has been an increasing trend in the prevalence of obesity along with socioeconomic progress. WWI, mainly representing weight-independent central obesity, is a more accurate indicator of obesity than BMI and WC. Klotho is known to be one of the root causes of several age-related illnesses. There has never been any prior evidence associating WWI and serum α-Klotho levels.

METHODS

The current cross-sectional investigation used data from the National Health and Nutrition Examination Survey (NHANES) 2013-2016. The calculation of each participant's WWI involved dividing their waist circumference in centimeters by the square root of their weight in kilograms. Using multivariable linear regression models, the association between serum Klotho concentrations and WWI was analyzed. Smoothed curve fitting was utilized to investigate the nonlinear connection. In addition, interaction tests and other subgroup analyses were carried out.

RESULTS

With an average age of 57.57 ± 10.81 years, 13,172 participants were enrolled in this study, of whom 51.45 % were female. After full adjustment, each unit increase in WWI was significantly associated with a decrease in Klotho by 23.18 ng/ml [β(95%CI) = -23.18 (-31.34, -15.02)]. Moreover, we uncovered that WWI had a stronger negative correlation with Klotho than other obesity markers, such as WC, body mass index (BMI), and a body shape index (ABSI).

CONCLUSIONS

To sum up, weight-adjusted-waist index levels were negatively associated with serum Klotho protein concentration and showed a stronger correlation than other obesity markers. Our findings indicated that WWI may be a predictor of reduced Klotho levels, and that controlling obesity in accordance with WWI may help lower the Klotho levels.

Association of triglyceride-glucose related indices with mortality among individuals with MASLD combined with prediabetes or diabetes

BACKGROUND

The prognostic significance of triglyceride-glucose (TyG)-related indices in individuals with metabolic dysfunction-associated steatotic liver disease (MASLD) combined with prediabetes or diabetes is not yet fully understood. In this study, we explored their predictive value for mortality in this specific population.

METHODS

Patients with MASLD were identified from the National Health and Nutrition Examination Survey (NHANES III) database. TyG and its related parameters [TyG-waist circumference (TyG-WC), TyG-waist-to-height ratio (TyG-WHtR), TyG-weight-adjusted waist index (TyG-WWI), and TyG-body mass index (TyG-BMI), ] were calculated. To examine the association between TyG-related indices and mortality risk, Cox regression models were utilized. Furthermore, we employed restricted cubic spline (RCS) analysis to investigate potential dose-response relationships. The predictive ability of the TyG indices for mortality was assessed by analyzing the time-dependent area under the curve (AUC).

RESULTS

In the cohort of patients with prediabetes or diabetes, 46.5% were diagnosed with MASLD. Over a median follow-up of 25.4 years, 1,163 individuals (53.9%) died, with 329 (15.3%) deaths attributed to cardiovascular causes and 78 (3.6%) to diabetes. Multivariate Cox regression models showed that TyG, TyG-BMI, TyG-WHtR, TyG-WWI, and TyG-WC were associated with all-cause and cardiovascular/diabetes-specific mortality. Furthermore, RCS analysis revealed a positive linear relationship between the TyG and TyG-WWI indices and all-cause mortality (p for nonlinear = 0.920; p = 0.525, respectively). In contrast, the TyG-WC, TyG-BMI, and TyG-WHtR indices exhibited a positive nonlinear association with all-cause mortality (p for nonlinear = 0.001; = 0.003; = 0.007, respectively). Time-dependent AUC curves demonstrated that the TyG-WWI index was the most robust predictor of both all-cause and cardiovascular mortality.

CONCLUSIONS

Elevated levels of TyG, TyG-BMI, TyG-WHtR, TyG-WWI, and TyG-WC indices were associated with a poorer prognosis in MASLD patients with prediabetes or diabetes, with TyG-WWI being the strongest predictor.

Evidence from NHANES 2011-2014: a correlation between the weight-adjusted-waist index and cognitive abilities in the United States

Background

Obesity exerts a significant detrimental impact on cognitive function. The weight-adjusted waist index (WWI) serves as a more precise indicator of visceral obesity that is independent of weight, in contrast to body mass index (BMI). Still, little research has been conducted on the interrelation between WWI and cognitive abilities. This investigation explored the link between WWI and older Americans' cognitive function.

Methods

Utilizing data from the 2011-2014 National Health and Nutrition Examination Cross-Sectional Survey, multiple linear regression analysis was used to assess the influence of WWI on cognitive abilities in those over 60. Three cognitive assessments were administered: the Animal Fluency Test (AFT), the Digit Symbol Substitution Test (DSST), and the Word Learning and Recall Module from the Coalition to Establish a Registry for Alzheimer's Disease (CERAD). We implemented threshold effects analysis and smoothed curve fitting to elucidate the nonlinear relationship. Additionally, we analyzed subgroups to check for variability.

Results

There were 2,762 participants, including1,504 (54.45%) females and 1,258 (45.55%) males. 53.77% of them had completed high school or above, and their average age was 69.05 ± 6.62. After controlling for confounding variables, the improved model predicted a negative connection between WWI and CERAD-Total, AFT, and DSST scores (all p < 0.05). Furthermore, we performed a smoothenable curve fitting between WWI and cognitive function scores, resulting in a nonlinear connection and a threshold saturation effect. We also executed subgroup analyses and interaction tests based on gender, race, educational background, marital status, diabetes, body mass index, alcohol consumption, hypertension, smoking habits, stroke, depression, and sleep quality to assess whether the relationship between WWI and cognitive function was affected by heterogeneity across different population segments. The subgroup analysis found no significant differences in cognitive performance associated with WWI across the various subgroups.

Conclusion

Higher WWI levels are associated with impaired cognitive function in Americans aged 60 and older.

Association between weight-adjusted-waist index and long-term prognostic outcomes in cardiovascular disease patients: results from the NHANES 1999-2018 study

BACKGROUND

As cardiovascular disease (CVD) morbidity and mortality increase yearly, this study aimed to explore the potential of the weight-adjusted-waist index (WWI) and its relation to long-term mortality in patients with CVD.

METHODS

The diagnosis of CVD was based on standardized medical condition questionnaires that incorporated participants' self-reported physician diagnoses. WWI (cm/√kg) is a continuous variable and calculated as waist circumference (WC, cm) divided by square root of body weight (kg). For analysis purposes, the participants were divided into four groups based on the quartiles (Q1 - Q4) of the WWI. The study's primary outcome was all-cause mortality in patients with CVD, with cardiovascular mortality as the secondary outcome, and sample weights and complex survey designs were used to ensure reliable, accurate results.

RESULTS

The final analysis included 4,445 study participants. In the fully adjusted model, the highest quartile (WWI > 12.05 cm/√ kg) showed a higher all-cause mortality rate compared with the lowest quartile (WWI < 11.03 cm/√ kg) (HR = 1.37, 95% CI: 1.03, 1.82, P < 0.05). The risk of all-cause mortality increased with WWI and showed a linear association in patients with congestive heart failure, heart attack (P-overall < 0.05, P - nonlinear > 0.05); WWI was nonlinearly associated with the risk of all-cause mortality in patients with coronary heart disease and angina (P-overall < 0.05, P - nonlinear < 0.05). Survival curve analysis further showed that all cause and cardiovascular mortality were higher in the high WWI group (Q4) (P < 0.001). The time-dependent receiver operating characteristic (ROC) curve showed that WWI's area under the curves (AUC) for 5- and 10-year survival rates were 0.76 and 0.792 for all-cause mortality and 0.734 and 0.757 for CVD mortality. WWI's AUC were higher than those of body mass index (BMI) and WC (all P < 0.01).

CONCLUSION

Our findings indicate that a high WWI is positively associated with an increased risk of all-cause mortality. Additionally, the high AUC values for WWI strengthen its potential as a meaningful prognostic marker, underscoring its utility in clinical practice for assessing long-term survival risk in patients with CVD.

The association between lipid-related obesity indicators and severe headache or migraine: a nationwide cross sectional study from NHANES 1999 to 2004

BACKGROUND

The connection between lipid-related obesity indices and severe headache or migraine in young and middle-aged people aged 20-60 remains ambiguous, and there are gaps in the discriminative ability of different indicators for severe headaches or migraines. Consequently, we set out to look into this association utilizing National Health and Nutrition Examination Survey (NHANES) data from 1999 to 2004.

METHODS

After the values of waist-to-height ratio (WHtR), body-mass index (BMI), body roundness index (BRI), visceral adiposity index (VAI), lipid accumulation product (LAP), triglyceride glucose index (TyG), cardiac metabolism index (CMI), waist triglyceride Index (WTI), conicity index (CI) and weight-adjusted waist index (WWI) were estimated, with minimal sufficient adjustment for confounders determined by directed acyclic graph (DAG), weighted univariable and multivariable logistic regression analyses were carried out to ascertain the relationship between them and migraine. Stratified analysis and cross-effect analysis were implemented to examine the variability of intergroup correlations. Restricted cubic splines (RCS) and receiver operating characteristic (ROC) were then employed to examine nonliner relationships and its discriminatory ability for severe headache or migraine, respectively.

RESULTS

3354 United States adults were involved in our study, of whom 839 (25.01%) had severe headache or migraine. After adjusting for relevant covariables, WHtR, BRI, BMI, LAP, WTI and VAI were all associated with migraine and WHtR (OR = 6.38, 95% CI: 2.25,18.09, P < 0.01) showed the best predictive ability. Additionally, WHtR, BMI, and BRI demonstrated linear dose-response relationships with the prevalence of migraine (all Poverall < 0.05, Pnon-linearity > 0.05).

CONCLUSIONS

Among those ten lipid-related obesity indicators evaluated in the study, WHtR, BMI and BRI demonstrated linear positive dose-response relationships with the prevalence of migraine in young and middle-aged individuals within the United States and WHtR showed the best predictive ability. Our study can provide important insight into epidemiological research and comprehensive management of obese patients with migraine.

Correlation between weight-adjusted waist index and coronary heart disease: NHANES 1999-2020

Background

The weight adjusted waist index (WWI) represents a novel indicator for assessing central obesity. The objective of this study is to investigate the association between WWI and coronary heart disease (CHD).

Method

The data of 44,528 participants in total were gathered from NHANES database from 1999 to 2020. WWI is calculated as the waist circumference (WC, cm) divided by the square root of the body weight (kg), and CHD was determined based on participants' self-reports. The association between WWI and CHD was examined using multiple logistic regression analysis, restrictive cubic spline (RCS), receiver operating characteristic (ROC) curve, mediation analysis, subgroup and interaction analyses.

Result

This was a cross-sectional investigation. A total of 44,528 participants were included [50.23% male; mean WWI 10.89 (0.01) cm/√kg]. The multivariate logistic regression analysis revealed that in three models, one-standard-deviation increment in WWI was associated with an increased probability of CHD occurrence by 2.39 (2.22,2.57),1.47 (1.32,1.65), and 1.15 (1.00,1.32) times, respectively. Additionally, RCS analysis indicated a linear relationship between WWI and CHD. and the ROC analysis results showed that the discriminatory power of WWI for CHD was superior to that of body mass index (BMI) and WC. Glycated hemoglobin (HbA1c) partially mediated the relationship between WWI and CHD. Subgroup and interaction analyses confirmed that age, systolic blood pressure, and diabetes status had a significant impact on the association between WWI and CHD (P for interaction <0.05).

Conclusion

The level of WWI has been demonstrated to be associated with an increased risk of CHD. Specifically, as WWI increases, the risk of CHD becomes higher. On this basis, it is hypothesized that WWI may potentially serve as an independent risk factor for CAD, thereby highlighting the substantial value of WWI in the identification and management of CHD.

A positive relationship between weight-adjusted waist index and non-alcoholic fatty liver disease: a study on US adolescents

Background

Non-alcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver condition in children, underscoring the urgent need for non-invasive markers for early detection in this population.

Methods

We utilized survey data from the National Health and Nutrition Examination Survey (NHANES) 2017-2020 regarding liver ultrasound transient elastography (LUTE) for the diagnosis of NAFLD (dependent variable), and used multiple logistic regression models to explore the association between weight-adjusted waist circumference index (WWI) and the prevalence of NAFLD in US adolescents. Smoothing curves and threshold effect analyses were used to assess the non-linear association between the independent variables and the dependent variable. Subgroup analysis was conducted to pinpoint particularly susceptible subgroups within our study cohort of 1,711 participants.

Results

Our findings indicated a positive correlation between WWI and NAFLD scores. Adjusting for all covariates revealed a significant association between increased WWI and the presence of NAFLD, with an odds ratio of 3.37 (95% CI: 2.74, 4.15). This association proved stronger than those observed with waist circumference, body mass index, and NAFLD. Stratifying WWI into quartiles showed a clear and strong positive correlation (P for trend < 0.0001). The results of smoothing curves and threshold effect analysis showed a non-linear relationship between WWI and NAFLD (LLR < 0.001). Notably, for WWI values below 10.65, a significant correlation was observed (OR = 5.25, 95% CI: 3.77,7.31). Additionally, our subgroup analysis revealed that WWI and NAFLD were associated more positively among male participants aged 16 years and older.

Conclusion

WWI is positively correlated with NAFLD in American adolescents and offers a straightforward and cost-effective method for identifying hepatic steatosis. The findings highlight the importance of focusing on individuals with a WWI below 10.65, where the risk of NAFLD increases. Priority should be given to the male adolescent population aged 16 and above.

Weight-adjusted waist index associated with bone mineral density in rheumatoid arthritis patients: a cross-sectional study

The research examined the association between weight-adjusted waist index (WWI) and bone mineral density (BMD) in individuals with rheumatoid arthritis, considering the impact of obesity on bone health. The association between WWI and BMD was examined utilizing weighted linear regression and smoothed curve fitting with data from NHANES 2005-2010, 2013-2014, and 2017-2018. Subgroup analysis verified the stability of the results. The study included a cohort of 983 rheumatoid arthritis patients. A significant negative correlation was found between WWI and BMD at the total femur, femoral neck, and lumbar spine (β = -0.03, 95% CI (-0.04, -0.02), p < 0.001; β = -0.02, 95% CI (-0.04, -0.01), p = 0.001; β = -0.04, 95% CI (-0.06, -0.02), p < 0.001). This negative association was not significantly influenced by factors like age, gender, race, education, PIR, diabetes, hypertension, sleep disorders, alcohol consumption, or smoking status (p > 0.05 for interaction). The findings indicate a negative correlation between WWI and BMD in the rheumatoid arthritis population. Key Points •A negative correlation was found between WWI and BMD at the total femur, femoral neck, and lumbar spine in the rheumatoid arthritis population.

Predictive properties of novel anthropometric and biochemical indexes for prediction of cardiovascular risk

OBJECTIVE

Our aim was to examine the correlation between CVDs and various anthropometric and biochemical indices in the Iranian population.

METHODS

9704 healthy individuals without CVD aged 35-65 were enrolled in our study. The anthropometric indices including Body Adiposity Index (BAI), Abdominal Volume Index (AVI), Body Roundness Index (BRI), Waist to Hip Ratio (WHR), Weight-adjusted Waist Index (WWI), Conicity Index (C-Index), A Body Shape Index (ABSI), Waist to Height Ratio (WHtR), Body Surface Area (BSA), Body Mass Index (BMI), Lipid Accumulation Product (LAP) and Visceral Adiposity Index (VAI) were calculated. The biochemical indices including Cardiac Risk Ratio (CRR), Atherogenic Index of Plasma (AIP), Triglycerides-Glucose Index (TyG), Cardiac Risk Index (CRI), Atherogenic Coefficient (AC), and high-sensitivity C-Reactive Protein (hs-CRP) were investigated. The association of the above indices with CVD was analyzed using logistic regression (LR) and the decision tree (DT) models.

RESULTS

The LR showed age, hs-CRP, AIP, AVI, LAP, and TyG had significant associations with CVDs in men (p-value < 0.002). Also, age, hs-CRP, LAP, TyG, BRI, VAI, and CRR had significant associations with CVDs in women (p-value < 0.002). The DT showed 95% of men with age > = 48, AIP > = 0.94, TyG > = 9.71, and AVI > = 14.24 had CVDs. Also, 97% of women with age > = 54, TyG > = 8.33, and hs-CRP > = 36.69 had CVDs.

CONCLUSION

Age, TyG, AIP, AVI, hs-CRP and LAP were the best predictors of CVD in men. Moreover, age, TyG, hs-CRP and BAI were the best indicators of CVD in women.

The association between weight-adjusted-waist index and psoriasis: A cross-sectional study based on NHANES 2009 to 2014

Weight-adjusted-waist index (WWI) is an anthropometric indicator of central obesity, which is calculated by dividing the waist circumference (WC) by the squared weight. The purpose of this study was to investigate the association between WWI and psoriasis in adults. Multivariate logistic regression and smoothing curve fitting were used to investigate the relationship between WWI and psoriasis based on data from the National Health and Nutrition Examination Survey (NHANES) 2009 to 2014. Subgroup analysis and interaction tests were employed to examine the population-level stability of this connection. There was a positive association between WWI and psoriasis in 15,932 participants > 20 years of age. In the fully adjusted model, each 1-unit increase in WWI was associated with a 14% increase in the risk of developing psoriasis [1.14 (1.01, 1.32)]. Participants in the highest quartile of WWI had a 38% higher risk of developing psoriasis than those in the lowest quartile [1.38 (1.01, 1.94)]. This positive association was more pronounced in males. WWI is positively associated with psoriasis in US adults. Our findings imply that WWI has the potential to improve psoriasis prevention in the general population.

U-shaped Association Between Weight-Adjusted-Waist Index and Arterial Stiffness Among Adult Hypertensive Patients: A Population-Based Study in the United States

The weight-adjusted-waist index (WWI) is an innovative measure of obesity that appears to surpass body mass index (BMI) in assessing lean body mass and fat mass. This study aimed to evaluate the relationship between WWI and AS in hypertensive adults in the United States. The study included 9753 adults diagnosed with hypertension from the National Health and Nutrition Examination Survey (NHANES), which spanned the years 2007-2016. WWI was calculated by dividing waist circumference (in cm) by the square root of body weight (in kg), and arterial stiffness (represented by estimated pulse wave velocity [ePWV]) was analyzed as the outcome. Weighted multiple linear regression and smooth curve fitting were used to test for linear and nonlinear associations. Threshold effects were determined using a two-part linear regression model. Additionally, subgroup analyses and interaction tests were conducted to gain a more in-depth understanding of the observed associations. The mean WWI of the participants was 11.32 ± 0.76. After multivariable adjustment, WWI showed a significant nonlinear association with ePWV, with a U-shaped association observed between the two. Specifically, WWI below the threshold of 10.23 was negatively associated with arterial stiffness (β = -0.39, 95% CI: -0.54 to -0.25), while WWI above the threshold of 10.23 was positively associated with arterial stiffness (β = 0.04, 95% CI: 0.01-0.07). To conclude, the present findings imply that maintaining WWI within an optimal range could reduce AS in hypertensive individuals and potentially decrease cardiovascular risk. However, this observation needs to be confirmed in large clinical trials.

Weight-Adjusted Waist Index: an anthropometric measure for frailty in older adults

PURPOSE

Current measures of frailty often rely on subjective assessments or complex scoring systems. This study aims to investigate the utility of a novel anthropometric measure, the Weight-Adjusted Waist Index (WWI), as a simple and objective predictive marker for frailty in older adults.

METHODS

This cross-sectional study included 847 patients aged 65 years and older. Comprehensive geriatric assessments and anthropometric measurements were conducted. Frailty was diagnosed using the Clinical Frailty Scale (CFS). The association between WWI and frailty was analyzed using multivariate logistic regression analysis.

RESULTS

The mean age of the participants was 74.9 ± 6 years, with 56.3% (n = 477) being women and 14.8% (n = 125) classified as frail. The frail group had a significantly higher WWI than the non-frail group (p < 0.001). In multivariate logistic regression analysis, WWI remained significantly associated with frailty, even after adjusting for other potential confounding factors (OR = 2.51, 95% CI 1.77-3.57, p < 0.001). The predictive ability of WWI for frailty was measured by the area under the receiver operating characteristic (ROC) curve, which was 0.705 (95% CI 0.67-0.73; p < 0.001). The optimal WWI threshold for predicting frailty was identified as > 12.

CONCLUSION

The Weight-Adjusted Waist Index shows significant potential as a simple and objective predictive marker for frailty in older adults.

Association Between Weight-Adjusted Waist Index and Emphysema in Adults in the United States: A Cross-Sectional Study Involving 44,949 Participants

Background: The relationship between obesity and respiratory diseases has been widely explored. In this context, the Weight-Adjusted Waist Index (WWI) has emerged as a novel metric for assessing visceral fat. This study aims to evaluate the association between WWI and the risk of emphysema in the U.S. population, by utilizing data from the 2001-2018 National Health and Nutrition Examination Survey (NHANES). Methods: A cross-sectional study was conducted using NHANES data from 2001 to 2018. Logistic regression models were applied to assess the relationship between WWI and emphysema risk. Interaction and subgroup analyses were performed to explore effect modifiers. Results: Our study included a total of 44,949 American adults. The results of the multivariable logistic regression analysis revealed an association between WWI and the incidence of emphysema. In the fully adjusted model, the probability of developing emphysema was 1.5 times higher in the group with WWI > 10.46 compared to those with WWI ≤ 10.46, with an odds ratio of [1.5 (1.1, 1.9), p = 0.003]. Subgroup analysis showed stronger associations among males, non-Hispanic Whites, and individuals with hypertension. Furthermore, we used a two-piece linear regression model and found a nonlinear association between WWI and emphysema, with a breakpoint at 12.5. Conclusions: Our findings indicate a significant association between WWI levels and emphysema. Larger-scale prospective studies are needed to further explore the role of WWI in emphysema.

Correlation between weight-adjusted-waist index and hypertension in the US population: based on data from NHANES 2005-2018

Objectives

This study aimed to investigate the association between the weight-adjusted waist index (WWI) and the prevalence of hypertension in U.S. adults.

Methods

Data were sourced from the National Health and Nutrition Examination Survey (NHANES) spanning 2005-2018. In our cross-sectional study, we focused on the non-institutional U.S. population over the age of 18 from various communities in the United States. WWI is derived by dividing waist circumference by the square root of body weight. The definition of hypertension was based on self-reported history of hypertension, antihypertensive drug use, and blood pressure measurements. Participants without complete information on WWI and hypertension were excluded. The independent relationship and consistency between WWI and hypertension were assessed through weighted multivariate regression. The Pearson correlation test was used to detect the association between WWI and BMI. Subgroup analyses were used to verify the stability of the relationship between WWI and the prevalence of hypertension, and interaction tests were also conducted by gender, age, smoking, and triglycerides.

Results

Among the 37,299 participants included, the hypertension prevalence was 33.9%. After adjusting for confounding variables, WWI demonstrated a significant association with hypertension. Individuals in the top quarter of WWI had a 2.27fold higher chance of hypertension prevalence compared with the bottom quarter (OR = 2.27, 95% CI 1.97-2.61; P < 0.0001). Subgroup analysis highlighted that this association was particularly pronounced in males aged ≤60 years.

Conclusion

The findings underscore a robust correlation between elevated WWI and a heightened risk of hypertension, especially in males aged ≤60 years.

Association between the weight-adjusted-waist index and Familial hypercholesterolemia: a cross-sectional study

OBJECTIVE

The weight-adjusted-waist index (WWI) is a novel obesity measurement indicator, and this study aims to determine the relationship between WWI and Familial hypercholesterolemia (FH).

METHODS

Using data from the National Health and Nutrition Examination Survey (NHANES) from 2017 to March 2020, cross-sectional data from 3698 participants were analyzed. The study examined the correlation between WWI and FH using multivariate logistic regression and smooth curve fitting, and conducted subgroup analysis and interaction tests.

RESULTS

The study sample consisted of 3698 subjects for whom the overall probable prevalence of FH was 5.43% and increased with WWI tertile (quantile 1: 4.00%; quantile 2: 4.94%; quantile 3: 7.34%); individuals with the highest WWI tertile were significantly more likely to have FH than those with the lowest tertile (OR = 4.60,95% CI: 2.00-10.60). Subgroup analysis and interaction tests showed significant significance between WWI and personal history of early Atherosclerotic cardiovascular disease (ASCVD), family history of early ASCVD and probable prevalence of FH (p < 0.05).

CONCLUSION

This study demonstrates a nonlinear positive correlation between WWI and FH. This may provide new ideas for the prevention and treatment of FH in the future.

Association Between Weight-Adjusted Waist Index and Periodontitis: A Cross-Sectional Study and Mediation Analysis

Aim

The research examined the correlation between the weight-adjusted waist index (WWI) and periodontal disease, as well as the intermediary influence of triglyceride glucose (TyG) index-related indicators, utilizing a health examination dataset.

Methods

This cross-sectional study included 39,522 subjects from health check-up database of Shanghai Health and Medical Center. The WWI was determined by applying a formula that includes dividing the waist circumference (WC) by the body weight's square root. Periodontitis diagnosis followed the Centers for Disease Control and Prevention and American Academy of Periodontology (CDC/AAP) classification. The correlation between the WWI and periodontitis was investigated through multivariate logistic regression and smoothing curve fitting. Subgroup analysis and interaction tests were also performed to verify the stability of the results. A mediation analysis was conducted to quantify the direct and indirect influences mediated by the TyG-related indicators [TyG, TyG -body mass index (TyG-BMI), TyG -waist-to-height ratio (TyG-WHtR), and TyG-waist circumference (TyG-WC)].

Results

Multivariable logistic regression analysis revealed the positive association of WWI and periodontitis (OR=1.37, 95% CI: 1.30-1.43). Compared to those in the lowest quartile of WWI, participants in the highest quartile exhibited a 82% higher likelihood of periodontitis (OR=1.82, 95% CI: 1.69-1.96). Subgroup analysis and interaction tests revealed that this positive correlation was consistent in gender, BMI, WC, smoking, drinking, hypertension, and dyslipidemia (P for interaction > 0.05), with some variations noted by age and diabetes status (P for interaction<0.05). Mediation analysis showed that the proportions mediated by TyG, TyG-BMI, TyG-WC, and TyG-WHtR on the association of WWI and periodontitis risk were 13.13%, 6.30%, 16.46% and 19.79%, respectively.

Conclusion

A higher WWI in Chinese adults was linked to an increased likelihood of periodontitis, and this correlation could be partially explained by elevated levels of TyG index-related indicators.

Association of weight-adjusted waist index with all-cause and cause-specific mortality among cancer survivors: a cohort study of the NHANES 1999-2018

Background

Obesity is becoming more widely acknowledged as a chronic illness that raises the risk of oncogenesis. This inquiry aimed to look into the correlation between cancer patient mortality and obesity, as measured by the weight-adjusted waist index (WWI).

Methods

We used continuous data from the National Health and Nutrition Examination Survey (NHANES) from 1999 to 2018 as the benchmark, with a follow-up validity period of December 31, 2019. First, we assessed the correlation between WWI and the all-cause and cause-specific execution of cancer sufferers using multivariable Cox proportional hazards models. Second, a smoothed curve fit was utilized to examine the relationship between WWI and both cause-specific and all-cause mortality in cancer patients. Lastly, we analyzed the relationship between WWI and both cause-specific and all-cause mortality in cancer patients, to find out if this link held across the population subgroup evaluation and impact analyses were used as well during the last step.

Results

With a median follow-up of 87.8 months, 1,547 (34.7%) of the 4,463 cancer patients had deceased. Among them, 508 (11.4%) succumbed to cancer, while 322 (7.2%) passed away due to cardiovascular disease. Multivariate Cox proportional hazards model of mortality among cancer patients revealed an all-cause mortality hazard ratio [HR=1.13; 95% CI (1.04, 1.23)] and cardiovascular mortality [HR=1.39; 95% CI (1.16, 1.67)]. Furthermore, for each unit increase in WWI, all-cause mortality was significantly higher in male cancer survivors than in female cancer survivors.

Conclusions

Our study reveals substantial correlations between WWI and all-cause and cardiovascular mortality in US cancer survivors, helping to identify cancer survivors at higher risk of death and thus potentially guiding targeted interventions.

Weight-adjusted waist index as a practical predictor for diabetes, cardiovascular disease, and non-accidental mortality risk

BACKGROUND AND AIM

Identifying a more suitable marker among various measures of adiposity, demonstrating strong associations and predictive ability for clinical use, remains a topic of debate. Weight-adjusted waist index (WWI) has been proposed as a novel index of adiposity, yet its exploration is limited, especially in Chinese populations. This study seeks to examine the associations between body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR), waist-to-height ratio (WHTR), weight-adjusted waist index (WWI), waist circumference divided by body mass to the power of 0.333 (WC/M0.333), visceral adiposity index (VAI), lipid accumulation product (LAP), and the incidence of diabetes, cardiovascular disease, and non-accidental mortality in Chinese populations. Furthermore, our goal is to compare the respective predictive values of these measures for these health outcomes.

METHODS AND RESULTS

This prospective cohort study included 21,750 subjects with a 9-year follow-up period. Cox proportional hazard models were used to investigate the relationship between eight anthropometric indexes and the incidence of diabetes, cardiovascular disease, and non-accidental mortality. The predictive value of these eight indexes was compared using the area under the curve metric. Significant positive associations were found between WWI and the risk of diabetes. Using the first quartile (Q1) of WWI as the reference group, hazard ratios with 95% confidence intervals for the risk of diabetes were 1.58 (0.98-2.55) for Q2, 2.18 (1.34-3.35) for Q3, and 2.27 (1.41-3.67) for Q4. Significant associations were observed with the highest quartile of WWI for the risk of cardiovascular disease [Q2: HR 1.45 (95% CI 1.06-1.98); Q3: 1.33 (0.97-1.83); Q4: 1.55 (1.13-2.14)] and risk of non-accidental mortality [Q2: 0.94 (0.80-1.11); Q3: 1.24 (1.04-1.48); Q4: 1.44 (1.16-1.79)]. Receiver operating characteristic analysis revealed that WWI exhibited superior discrimination and accuracy in predicting cardiovascular disease and non-accidental mortality compared to other adiposity indexes (BMI, WC, WHR, WHTR, WC/M0.333, VAI, and LAP).

CONCLUSION

WWI exhibited the most robust and consistent association with the incidence of cardiovascular disease and non-accidental mortality. Given its simplicity and widespread use, WWI emerges as a novel and practical predictor of diabetes, cardiovascular disease, and non-accidental mortality among the eight adiposity indexes investigated in this study.

Gender differences in weight-adjusted waist index in elderly inhabitants of a geriatric center

INTRODUCTION AND AIM

Weight-adjusted waist index (WWI) represents a novel anthropometric measure for assessing obesity. Bearing in mind that there is insufficient data in the literature regarding gender differences in WWI values, the aim of the current study was to examine gender differences in WWI values among older adults.

Association between weight-adjusted waist index with incident stroke in the elderly with hypertension: a cohort study

The objective of this study was to ascertain the relationship between the weight-adjusted waist index (WWI) and the risk of stroke in an elderly hypertensive population, a relationship that has not been previously elucidated. The Cox regression model was employed to assess the correlation between baseline WWI measurements and the incidence of stroke. To further elucidate the shape of the association between baseline WWI and stroke, restricted cubic splines were employed. Furthermore, subgroup analyses and interaction tests were carried out to investigate potential heterogeneities. Our study cohort comprised 4962 hypertensive individuals aged 60 years or older with no prior history of stroke. Over a median follow-up of 3.2 years, we found 547 new-onset stroke cases. After adjusting for confounding variables, the Cox regression analysis revealed a positive association between baseline WWI and the risk of stroke, with hazard ratios (HRs) escalating progressively as WWI values increased. When compared to the lowest quartile of WWI, the highest quartile demonstrated an HR of 1.87 (95% CI, 1.44-2.42) for stroke. Subgroup analyses confirmed the consistency of this relationship across different demographic and clinical strata. The study findings indicate that an elevated WWI is significantly related with a higher risk of new-onset stroke among elderly patients with hypertension. These results underscore the importance of WWI as a potential risk stratification tool. To confirm these results and explore the causal mechanisms behind the observed correlation, more study is necessary.

Correlation between obstructive sleep apnea and weight-adjusted-waist index: a cross-sectional study

Background

Obesity is recognized as a prominent factor in the pathogenesis of obstructive sleep apnea (OSA). The weight-adjusted-waist index (WWI) has emerged as a novel metric for assessing adiposity. The study aimed to investigate the potential correlation between WWI and OSA.

Methods

In this study, a cross-sectional analysis was conducted on the data from the National Health and Nutrition Examination Survey (NHANES) during the period from 2013 to 2020. To examine the correlation between WWI and OSA, multivariate logistic regression, smooth curve fitting, subgroup analysis and receiver operating characteristic (ROC) curve were employed.

Results

Among the total 18,080 participants, 9,050 were categorized as having OSA. It was observed that as the quartile range of WWI increased, there was a gradual rise in the prevalence of OSA (37.4% vs. 50.3% vs. 55.1% vs. 57.5%, p < 0.001). Logistic regression analyses demonstrated a significant positive correlation between WWI and the risk of OSA, even after accounting for potential confounders (OR = 1.314, 95% = 1.223, 1.411). Subgroup analysis further revealed a stronger correlation between OSA and WWI among individuals with normal weight, those under 50 years old, and those engaging in moderate physical activities. Smooth curve fitting identified a positive non-linear correlation, with an inflection point at 11.678. ROC analysis indicated that WWI (AUC = 0.664) can serve as a more robust predictor for OSA compared to BMI and waist circumference.

Conclusion

This study provides evidence that elevated levels of WWI are correlated with an increased risk of OSA, indicating the potential utility as predictive indicators for OSA.

Association of weight-adjusted-waist index with all-cause and cardiovascular mortality in individuals with diabetes or prediabetes: a cohort study from NHANES 2005-2018

Weight-adjusted waist index (WWI) is a new marker of central obesity. This study explored the association of WWI with all-cause and cardiovascular disease (CVD) mortality in individuals with diabetes or prediabetes. 6551 participants with diabetes or prediabetes from the National Health and Nutrition Examination Survey (NHANES) records between 2005 and 2018 were included. The association of WWI with all-cause and CVD mortality was assessed using Kaplan-Meier survival analysis, Cox proportional hazards model (Cox regression), and restricted cubic spline (RCS). The predictive value of WWI for mortality was analyzed using time-dependent receiver operating characteristic curves (ROC). There were 1083 all-cause deaths and 360 CVD deaths. Multivariable-adjusted Cox regression analyses showed WWI was positively correlated with the risk of all-cause and CVD mortality in subjects with diabetes or prediabetes. Multivariate-adjusted RCS analyses showed a linear and positive correlation of WWI with all-cause mortality risk, and a nonlinear relationship with CVD mortality, with a threshold of 12.35. The area under the curve (AUC) for 3, 5, and 10-years survival for all-cause mortality was 0.795, 0.792, and 0.812, respectively, and for CVD mortality was 0.815, 0.833, and 0.831, respectively. WWI is a valuable predictor of all-cause mortality risk in patients with diabetes and prediabetes, and a valuable predictor of CVD mortality risk when patients with diabetes and prediabetes are considered as a whole.

Weight-adjusted waist index and disability: a cohort study from CHARLS

BACKGROUND

The association between weight-adjusted waist index (WWI) and disability is unclear. This study aimed to assess the relationship between WWI and disability in middle-aged and elderly Chinese individuals and provide more predictive indicators for disability prevention.

METHODS

In this study, 13,015 middle-aged and older adults aged 45 years and above who were surveyed in 2011 by the China Health and Aging Tracking Survey (CHARLS) database were selected, and 8344 respondents with complete data were included for cohort analysis after seven years of follow-up. Information on clinical demographic characteristics, anthropometric indices, assessment of disability, and related covariates were collected, and the presence or absence of disability was assessed by the disability scale. WWI was calculated by dividing the waist circumference (cm) by the square root of the body weight (kg). Cox proportional hazards model was used to analyze the association between WWI and disability after follow-up.

RESULTS

Our study found that 2912 of 8344 participants had disability after seven years of follow-up, and disability incidence was approximately 34.9%. Age, sex, place of residence, chronic disease, depression, waist circumference, and WWI were significantly associated with disability in univariate analysis. Among them, there was a positive association between WWI as a continuous variable and incidence of disability (hazard ratio (HR) = 1.26, 95% CI: 1.22-1.31, p < 0.001). WWI was transformed into categorical variables using quartiles as cutoffs for disability regression analysis. After adjusting covariates, HR values in the 2nd, 3rd and 4th quantile showed an increasing trend compared with the 1st quantile, and the risk of disability among WWI subjects in the 4th quantile increased by 43% (95% CI: 1.24-1.64). P values for the trend test in the model were all < 0.001. In subgroup analyses, the positive association between WWI and risk of disability remained robust for sex, age, alcohol consumption, smoking status, education level, marital status, and place of residence after adjusting for all covariates considered in this study.

CONCLUSIONS

WWI is a new and reliable obesity-related indicator that can be used for disability prevention. WWI can be detected and controlled for reducing the risk of disability.

Weight-adjusted waist index is positively and linearly associated with all-cause and cardiovascular mortality in metabolic dysfunction-associated steatotic liver disease: findings from NHANES 1999-2018

BACKGROUND

Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most common chronic liver disease. Body mass index (BMI) is the most used obesity index but has important limitations. The weight-adjusted waist index (WWI) is a novel obesity metric and accurately reflects body composition. We explored the association of WWI with all-cause and cardiovascular disease (CVD) mortality in MASLD.

METHODS

Adult participants with MASLD were included from NHANES 1999-2018. WWI was calculated by dividing the waist circumference (WC) by the square root of body weight. MASLD was diagnosed by the presence of hepatic steatosis and at least one cardiometabolic risk factor in the absence of other causes of steatosis. A fatty liver index ≥60 suggested the presence of hepatic steatosis. Mortality data was obtained by prospectively linking to the National Death Index. Multivariate Cox proportional hazards regression analyses were used to explore these associations and multiple adjustment models were constructed including crude, partial, and fully adjusted models.

RESULTS

After adjusting for all covariates including BMI, WWI remained positively and linearly associated with all-cause and CVD mortality in MASLD (hazard ratios [HR] 1.247 and 1.218, respectively). Higher WWI was associated with a significantly increased risk of mortality (both p for trend <0.05). There was an "obesity paradox" between BMI and all-cause mortality in MASLD, with significantly lower all-cause mortality in those with overweight/obesity compared to normal BMI (HR 0.625 and 0.596, respectively, p for trend = 0.024), and no association between BMI and CVD mortality. Interaction analyses indicated that these associations were influenced by several demographic variables and disease status. Time-dependent receiver operating characteristic curves indicated that the predictive value of WWI for mortality in MASLD was higher than that of BMI, WC, and waist-to-height ratio across all follow-up durations.

CONCLUSIONS

WWI was positively and linearly associated with all-cause and CVD mortality in MASLD, whereas BMI did not accurately reflect mortality risk. WWI provided the optimal predictive value for mortality compared to traditional obesity indicators. These findings emphasize the potential use of WWI as a novel obesity indicator for mortality risk assessment, stratification, and prevention in MASLD.

Association Between Weight-Adjusted Waist Index and Albuminuria in Type 2 Diabetes Mellitus in the Chinese Population

Purpose

This study aimed to investigate the relationship between weight-adjusted waist index (WWI) and albuminuria in patients with type 2 diabetes mellitus (T2DM) in the Chinese population.

Patients and Methods

A total of 860 adult patients in the Department of Endocrinology of the Affiliated Hospital of Jiangsu University were retrospectively analyzed from June 2018 to September 2023. Correlations between WWI and albuminuria (albumin-to-creatinine ratio (UACR) ≥ 30 mg/g were defined as albuminuria) were analyzed using the Pearson and Spearman methods. The associations between albuminuria and Age, gender, body mass index (BMI), waist circumference/ hip circumference (WHR), systolic blood pressure(SBP), diastolic blood pressure (DBP), fasting plasma glucose (FPG), 2-hour postprandial plasma glucose (2h PG), fasting plasma insulin (FIns), 2-h postprandial insulin (2hINS), glycosylated hemoglobin (HbA1c), WWI, homeostasis model assessment of insulin resistance (HOMA-IR) were analyzed via binary logistic regression.

Results

Compared with the normal albumin group, serum urea nitrogen, serum creatinine, UACR, and WWI levels in the albuminuria group were significantly increased, while estimated glomerular filtration rate (eGFR) levels were significantly decreased (P < 0.05). Correlation analyses revealed that WWI was positively correlated with UACR but negatively correlated with urea nitrogen, serum creatinine, and eGFR (P < 0.05). Binary logistic regression analyses indicated that WWI was an independent risk factor for albuminuria in T2DM patients. Receiver operating characteristic curve results showed that the area under the curve for albuminuria as predicted by WWI was 0.605 [95% CI = (0.563-0.646), P < 0.001].

Conclusion

WWI is independently associated with albuminuria in the Chinese patients with type 2 diabetes and may serve as a simple indicator for albuminuria risk assessment.

The association between weight-adjusted waist index and sleep disorders in U.S. adults: results from NHANES 2005-2008

The detrimental effects of obesity on sleep disorders have garnered a lot of interest. The weight-adjusted waist index (WWI) is a newly developed anthropometric index calculated in terms of weight and waist circumference. The body mass index has been employed to evaluate obesity in the majority of studies that connect obesity to sleep disorders. This study seeks to investigate the correlation between WWI and sleep disorders among adults in the United States. This cross-sectional study was part of the National Health and Nutrition Examination Survey and included adults aged >20 from 2005 to 2008. This study investigated the linear relationship between sleep disorders and WWI using weighted binary logistic regression models. Nonlinear relationships were characterized using smooth curve fitting and threshold effects analyses. After that, based on variables like gender, age, marital status, diabetes, hypertension, and smoking, subgroup analyses were performed. Our study included 9869 participants who were at least 20 years old. Higher WWI was linked to greater odds of sleep disorders prevalence, according to weighted binary logistic regression (odds ratio = 1.15; 95% confidence interval, 1.10, 1.20). In subgroup analyses based on age, marital status, diabetes, hypertension, and smoking, this connection remained robust. However, there were notable differences in this connection depending on gender. Furthermore, a nonlinear correlation with inflection points between WWI and sleep disorders was shown using smooth curve fitting. The nonlinear association between WWI and sleep disorders has an inflection point of 8.1 cm/√kg, as indicated by the threshold effect analyses. A higher WWI exposure may elevate the odds of sleep disorder prevalence, underscoring the importance of considering WWI in the prevention and management of sleep disorders.

The association between the weight-adjusted-waist index and frailty in US older adults: a cross-sectional study of NHANES 2007-2018

Objective

This study aimed to evaluate the relationship between the weight-adjusted waist circumference index (WWI) and the frailty in American adults aged over 60 years.

Methods

We utilized data from the National Health and Nutrition Examination Surveys (NHANES) spanning from 2007 to 2018. WWI was calculated using the square root of waist circumference (cm) divided by body weight (kg). The frailty index ≥ 0.25 was employed to assess frailty. Weighted multivariate logistic regression was conducted to explore the association between WWI and frailty. Generalized Additive Modeling (GAM) was used to explore potential non-linear relationships. Receiver operating characteristic curve (ROC) analysis was used to assess the predictive ability of WWI for frailty.

Results

The study encompassed 7765 participants. Higher WWI was significantly associated with higher odds of frailty. In the fully adjusted model, each unit increase of WWI was associated with an 82% increased odds of frailty (OR: 1.82, 95% CI: 1.61 - 2.06; P < 0.001). GAM found significant nonlinear relationships and threshold effects.

Conclusion

The study presented a robust correlation between elevated WWI and increased odds of frailty among American older adults. However, these findings require further validation in large-scale, prospective studies.

The relationship between cardiometabolic index and infertility in American adults: a population-based study

Background

Infertility is a fertility disorder caused by various factors, with lipid metabolism playing a crucial role in its development. The cardiometabolic index (CMI), which combines blood lipids (TG/HDL-C) and obesity-related parameters (WHtR), is a new quantitative indicator. This study used NHANES data to investigate the relationship between CMI and the incidence of infertility.

Methods

We utilized data from women who took part in the National Health and Nutrition Examination Survey (NHANES) from 2015 to March 2020 to calculate the CMI index. Subsequently, we used multivariate logistic regression, smooth curve fitting, and subgroup analysis to investigate the relationship between the CMI index and infertility.

Results

The logistic regression model revealed a significant positive correlation between the CMI index and infertility, even after adjusting for all confounding variables (OR=3.23, 95%CI: 1.55-6.73, p=0.0017). This association remained consistent across all subgroups (p>0.05 for all interactions). Smooth curve fitting demonstrated a positive nonlinear relationship between CMI and infertility. However, the CMI index had limited diagnostic power for infertility (AUC=0.60, 95%CI: 0.56-0.65). However, the CMI-BMI index combined with BMI had good predictive performance (AUC=0.722, 95%CI: 0.676-0.767).

Conclusion

The CMI index shows a positive correlation with infertility, but its diagnostic value is restricted. The combination with BMI has good diagnostic value. Further investigation is required to determine the effectiveness of the CMI index as an early indicator of infertility.

Association between weight-adjusted waist index and overactive bladder: a cross-sectional study based on 2009-2018 NHANES

Background

The weight-adjusted waist index (WWI) is a novel obesity indicator that appears to outperform the body mass index (BMI) and waist circumference (WC) in assessing both overweight and obesity. Studies have demonstrated the relationship between obesity and overactive bladder (OAB). The purpose of this study is to examine the correlation between WWI and OAB.

Methods

This research utilizes data from the National Health and Nutrition Examination Survey (NHANES) collected between 2009 and 2018. Each participant's WWI was calculated as their WC in centimeters by the square root of weight in kilograms. The Overactive Bladder Symptom Score (OABSS) questionnaire is used to determine whether a participant has OAB. Multivariate logistic regression and generalized additive model analysis were employed to investigate the relationship between WWI and OAB. We used smoothing curve fitting to explore non-linear relationships. Additionally, subgroup analysis and interaction tests are conducted.

Results

In this cross-sectional study involving 35,950 subjects, we found that individuals with a higher WWI have a higher risk of OAB (OR = 1.41, 95% CI: 1.02-1.74). Subgroup analysis and interaction testing showed that the relationship between WWI and OAB is consistent across various population characteristics. Smoothing curve fitting reveals a positive non-linear relationship between WWI and OAB. Furthermore, the association between WWI and OAB is stronger than that of other obesity-related indicators.

Conclusion

Weight-adjusted waist index may be able to predict the incidence of OAB and that WWI-based obesity management may help to reduce the risk of OAB.

Relationship between weight-adjusted-waist index and blood pressure as well as incident hypertension among middle-aged and elderly Chinese: A longitudinal study

BACKGROUND AND AIM

The Weight-Adjusted Waist Index (WWI) is a novel obesity metric linked to metabolic disorders. Its relationship with blood pressure and hypertension prevalence in middle-aged and elderly Chinese is unclear. This study examined the association between WWI, blood pressure, and hypertension incidence.

METHODS AND RESULTS

This cross-sectional study included 9298 participants from the China Health and Retirement Longitudinal Study, with 4120 non-hypertensive individuals enrolled in the cohort study. In the cross-sectional analysis, WWI was positively associated with systolic blood pressure (SBP) (Beta 0.88, 95% CI: 0.57-1.21, p < 0.001), showing stronger correlations than waist circumference (WC) (Beta 0.20, 95% CI: 0.16-0.23, p < 0.001) and body mass index (BMI) (Beta 0.63, 95% CI: 0.52-0.74, p < 0.001). WWI also showed a positive association with diastolic blood pressure (DBP) (Beta 0.51, 95% CI: 0.32-0.69, p < 0.001), stronger than those with WC (Beta 0.13, 95% CI: 0.11-0.15, p < 0.001) and BMI (Beta 0.43, 95% CI: 0.37-0.50, p < 0.001). In the longitudinal cohort study, there were 1325 (32%) incident cases of hypertension by the end of follow-up. WWI was positively associated with incident hypertension (OR 1.11, 95% CI: 1.04-1.18, p = 0.001), with a stronger predictive value than WC (OR 1.02, 95% CI: 1.01-1.03, p < 0.001) and BMI (OR 1.04, 95% CI: 1.02-1.06, p < 0.001).

CONCLUSION

Elevated WWI may serve as an independent risk factor for incident hypertension in the middle-aged and elderly Chinese population.

Correlation of weight-adjusted waist index with diabetic retinopathy in US adults aged ≥ 40 years: the NHANES 2005-2008

The effect of obesity on diabetic retinopathy (DR) has been under scrutiny in recent years. The weight-adjusted waist index (WWI) has been reported to better assess the degree of centripetal obesity in humans, with a higher WWI indicating a higher amount of body fat. The present study is the first to investigate the relationship between WWI and DR and to assess the difference in the predictive ability of WWI and other obesity indices for DR. This cross-sectional study utilized data from the National Health and Nutrition Examination Survey (NHANES) from 2005 to 2008. Researchers collected complete anthropometric data (weight and waist circumference), dilated fundus images, and adult baseline information. Independent interactions between WWI and DR were investigated using multivariate regression and subgroup analyses. In addition, nonlinear associations and threshold effects between WWI and DR were searched for by smoothed curve fitting and by two-stage linear regression modeling. Finally, the receiver operating characteristic curve (ROC) was plotted to compare the predictive power of WWI with other indices of obesity for DR. A total of 1228 eligible patients with diabetes were collected in this study. There were 631 (51.38%) males and 597 (48.62%) females. Among them, 545 (44.38%) were without diabetic retinopathy, 555 (45.20%) had mild diabetic retinopathy, 100 (8.14%) had moderate/severe diabetic retinopathy and 28 (2.28%) had proliferative diabetic retinopathy (PDR). In the fully adjusted model, each unit increase in WWI was associated with a corresponding 31% reduction in the prevalence of DR [OR (95% CI) = 0.69 (0.58, 0.83)]. Compared with subjects in the lowest quartile (quartile 1), subjects in the highest quartile of WWI levels (quartile 4) were 45% less likely to have DR [OR (95% CI) = 0.55 (0.38, 0.78)]. In the case of female participants, a U-shaped correlation was observed between WWI and DR with an inflection point of 11.49. WWI also possesses a better predictive ability for DR compared to obesity indicators such as weight, BMI, and ABSI. This study showed a negative association between WWI and DR in the U.S. population aged 40 years and older.

The association between Weight-adjusted-Waist Index (WWI) and cognitive function in older adults: a cross-sectional NHANES 2011-2014 study

BACKGROUND

The impact of obesity on cognitive function has engendered considerable interest. Weight-adjusted waist index (WWI) has emerged as a novel and innovative marker of obesity that reflects weight-independent abdominal obesity. However, the association between WWI and cognitive function remains unclear. To address this gap, the present study aims to explore the relationship between weight-adjusted waist index (WWI) and cognitive performance in older adults.

METHODS

We conducted a cross-sectional investigation using datasets from the National Health and Nutrition Examination Survey (NHANES) 2011-2014. The study included 3,472 participants (48.59% male, 51.41% female) of various races (Mexican American, Other Hispanic, Non-Hispanic White, Non-Hispanic Black, and Other), with a mean age of 69.95 years (SD = 6.94). Multivariate regression and smoothing curve fitting were used to investigate the linear and nonlinear relationship between WWI and cognitive performance in the following domains: learning and memory, verbal fluency, and processing speed, as measured by Consortium to Establish a Registry for Alzheimer's Disease Word Learning subtest (CERAD-WL), Animal Fluency Test (AFT), and Digit Symbol Substitution Test (DSST), respectively. Subgroup analysis and interaction tests were conducted to examine the stability of this relationship across groups. Machine learning models based on random forests were used to analyze the predictive performance of WWI for cognitive function.

RESULTS

A total of 3,472 participants were included in the analysis. The results revealed significant negative associations between WWI and low scores on the CERAD-WL [-0.96 (-1.30, -0.62)], AFT [-0.77 (-1.05, -0.49)], and DSST [-3.67 (-4.55, -2.79)]. This relationship remained stable after converting WWI to a categorical variable. In addition, this significant negative association was more pronounced in men than women and diminished with advancing age. Non-linear threshold effects were observed, with correlations intensifying between WWI and CERAD-WL when WWI surpassed 12.25, AFT when WWI surpassed 11.54, and DSST when WWI surpassed 11.66.

CONCLUSIONS

A higher WWI, indicating increased abdominal obesity, was associated with deficits in learning, memory, verbal fluency, and processing speed among older adults. These findings suggest that abdominal obesity may play a crucial role in cognitive decline in this population. The stronger relationship observed between WWI and cognition in men highlights the need for gender-specific considerations in interventions targeting abdominal obesity. The results demonstrate the importance of interventions targeting abdominal obesity to preserve cognitive performance in older adults.