The weight-adjusted-waist index predicts all-cause and cardiovascular mortality in general US adults

Association between sarcopenia and weight-adjusted waist index in male patients with type 2 diabetes

BACKGROUND

The Weight-adjusted-waist index (WWI) has emerged as a predictive factor for a range of metabolic disorders. To date, the predictive value of the WWI in relation to sarcopenia in individuals with diabetics has not been extensively explored. This study aims to investigate the impact of the WWI on the prevalence of sarcopenia among patients with type 2 diabetes mellitus (T2DM).

METHOD

In this study, we enrolled 417 patients with T2DM from the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University between Dec. 2023 and Apr. 2024. The relationship between the WWI and the prevalence of sarcopenia in T2DM patients was evaluated using multivariate logistic regression, subgroup analysis, restricted cubic spline (RCS) analysis, and receiver operating characteristic (ROC) curve analysis.

RESULTS

Among the 417 patients with T2DM, 76 (18.22%) were identified as having sarcopenia. The prevalence of sarcopenia across the WWI quartile categories, from the first to the fourth quartile, was 8.65%, 8.57%, 20.19% and 8.65% respectively. Multivariate logistic regression analysis revealed that, after adjusting for covariates, a higher WWI was an independent risk factor for sarcopenia in male T2DM patients (OR = 1.836, 95% CI: 1.216-2.772, P = 0.004). This association was not observed in female patients. Subgroup analysis further revealed a stronger correlation between WWI and sarcopenia among male patients with higher HbA1c levels. In males, RCS regression demonstrated a non-linear positive correlation, with an inflection point at a WWI of 10.42 cm/√kg. Finally, the area under the ROC curve (AUC) for the WWI was 0.612.

CONCLUSIONS

WWI emerges as a robust and independent risk factor for sarcopenia in male patients with T2DM. WWI may serve as an accessible and cost-effective tool for identify sarcopenia in patients with diabetes.

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.

Correlation of the weight-adjusted waist circumference index with Klotho in the United States: differences by sex

The relationship between the weight-adjusted waist circumference index (WWI) and the senescence-inhibitory protein Klotho remains unknown. Therefore, this study aimed to investigate the relationship between WWI and soluble Klotho (s-Klotho). This study analyzed 9,928 participants based on the 2007-2016 National Health and Nutrition Examination Survey (NHANES). Three multiple linear regression models and a restricted cubic spline (RCS) were constructed to assess the association between WWI and s-Klotho levels. Further stratified analyses and interaction tests were performed to evaluate the stability of this association. Piecewise multivariate regression modeling was applied to detect threshold effects. The fully adjusted model showed a negative correlation between continuous WWI and s-Klotho levels (β = -23.65, 95% CI: -36.55, -10.76, P < 0.001). When WWI was grouped into quartiles, participants in the highest quartile had significantly lower circulating s-Klotho levels than those in the lowest quartile (β = -40.65, 95% CI: -64.20, -17.10, P = 0.001). The RCS curves showed a linear negative correlation between WWI and s-Klotho. Further stratified analyses showed that the correlation between WWI and s-Klotho remained stable in most conditions, except for gender. A nonlinear relationship and saturation effect were observed between WWI and s-Klotho in females, with an inflection point of 11.38 cm/√kg (P for overall < 0.001; P for non-linearity = 0.013). However, no significant correlation was observed in males. There is a significant negative correlation between WWI and s-Klotho levels. Proper management of central obesity in middle-aged and older women may be beneficial in delaying senescence.

Relationship between weight-adjusted-waist index and all-cause and cardiovascular mortality in individuals with type 2 diabetes

AIM

To investigate the relationship between the weight-adjusted-waist index (WWI) and all-cause mortality as well as cardiovascular mortality in individuals with type 2 diabetes.

METHODS

We used data from the National Health and Nutrition Examination Survey (NHANES) from 1999 to 2018 and the UK Biobank database. Restricted cubic spline curves and Cox proportional hazards models were employed to assess hazard ratios (HRs) and 95% confidence intervals (CIs) for all-cause mortality.

RESULTS

In the UK Biobank database, compared with the lowest WWI quartile, the HR for all-cause and cardiovascular death in the highest quartile was 1.846 (95% CI 1.687-2.019) and 2.118 (95% CI 1.783-2.517), respectively, in the fully adjusted model. In the NHANES database, compared with the lowest WWI quartile, the highest quartile had an HR of 1.727 (95% CI 1.378-2.163) for all-cause death and 1.719 (95% CI 1.139-2.595) for cardiovascular death in the fully adjusted model.

CONCLUSIONS

Our study indicates that WWI has a long-term synergistic negative impact on all-cause mortality and cardiovascular mortality in individuals with type 2 diabetes. The WWI is an independent predictor of mortality in individuals with type 2 diabetes.

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.

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 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.

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 of the weight-adjusted waist index with hypertension in the context of predictive, preventive, and personalized medicine

Objective

Hypertension (HTN) is a prevalent global health concern. From the standpoint of preventive and personalized medicine (PPPM/3PM), early detection of HTN offers a crucial opportunity for targeted prevention and personalized treatment. This study aimed to evaluate the association between the weight-adjusted waist index (WWI) and HTN risk.

Methods

A case-control study using data from the National Health and Nutrition Examination Survey (NHANES) from 2005 to 2018 was conducted. Logistic regression models assessed the association between WWI and HTN. Subgroup analyses explored differences in age, sex, ethnicity, and diabetes status. Restricted cubic spline (RCS) analyses examined potential nonlinear relationships.

Results

A total of 32,116 participants, with an average age of 49.28 ± 17.56 years, were included in the study. A significant positive association between WWI and the risk of HTN was identified (odds ratio [OR], 2.49; 95% CI, 2.39-2.59; P < 0.001). When WWI was categorized into quartiles (Q1-Q4), the highest quartile (Q4) exhibited a stronger association compared to Q1 (OR, 2.94; 95% CI, 2.65-3.27; P < 0.001). Subgroup analyses indicated that WWI was a risk factor for HTN across different populations, although variations in the magnitude of effect were observed. Furthermore, the findings from the RCS elucidated a nonlinear positive correlation between WWI and HTN.

Conclusion

WWI is independently associated with HTN risk, highlighting its potential as a risk assessment tool in clinical practice. Incorporating WWI into early detection strategies enhances targeted prevention and personalized management of HTN.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13167-024-00375-3.

The association between weight-adjusted waist circumference index and cardiovascular disease and mortality in patients with diabetes

Cardiovascular disease (CVD) is a significant health concern, particularly among patients with diabetes. The weight-adjusted waist circumference index (WWI), a novel metric that accounts for central obesity, has shown potential in predicting obesity-related health risks. This study aimed to evaluate the association of WWI with CVD and mortality in patients with diabetes. Utilizing data from the National Health and Nutrition Examination Survey from 1999 to 2020, WWI was calculated by dividing waist circumference (WC) by the square root of body weight. Multivariate logistic regression, multivariate Cox regression and restricted cubic spline curves were used to assess the association between WWI and the prevalence of CVD and mortality in patients with diabetes, subgroup and sensitivity analyses were carried out to delve into the stability of the findings. The predictive performance of WWI was evaluated using the area under the receiver operating characteristic curve (ROC). This study included 8,005 individuals with diabetes. With the increase in WWI values, the risk of developing CVD and the likelihood of mortality progressively rise. The fully adjusted continuous model indicated a 28% higher chance of developing CVD and a 25% higher risk of all-cause mortality for each one-unit increase in WWI. When using the lowest quartile of WWI as the reference category, the highest quartile was linked to an increased risk of CVD (OR 1.66; 95% CI 1.10-2.50, p = 0.015) and all-cause mortality (HR 1.53, 95% CI 1.27-1.83, p < 0.001) among patients with diabetes. Subgroup and sensitivity analyses confirmed that these associations were consistent and stable in most different demographics. The ROC analysis indicated that WWI had a higher predictive capacity for CVD and all-cause mortality than WC, waist to hip ratio, and weight to height ratio. The WWI was significantly associated with the prevalence of CVD and all-cause mortality among patients with diabetes in the United States and may serve as a useful tool for identifying individuals at risk.

Association of weight-adjusted waist index with cardiovascular disease and mortality among metabolic syndrome population

Metabolic syndrome (MetS) is prevalent and significantly impacts global public health, with obesity being a major risk factor for cardiovascular diseases (CVD) and mortality. Traditional metrics like body mass index (BMI) have limitations in assessing obesity-related risks. The weight-adjusted waist circumference index (WWI) has emerged as a novel obesity metric, this study aimed to evaluate the association of WWI with CVD and mortality in MetS patients. This study used data from 12,641 participants with MetS, derived from the National Health and Nutrition Examination Survey (NHANES) conducted from 1999 to 2020. The WWI was calculated, and its association with CVD and mortality was assessed using multivariate logistic and Cox regression models. The study controlled for potential confounders and performed subgroup and sensitivity analyses to validate the robustness of the findings. The predictive performance of WWI was evaluated using the area under the receiver operating characteristic curve (ROC). Kaplan-Meier (KM) curves further were used to evaluate the associations between WWI and mortality of the MetS population. As WWI values escalated, there was a proportional rise in the risk of CVD and mortality in MetS. The fully adjusted continuous model revealed a 32.0% elevated likelihood of CVD development, a 69.5% increased probability of heart failure (HF), a 51.1% heightened risk for CVD mortality, and a 22.8% augmented risk for all-cause mortality with each one-unit increment in WWI. Comparing the highest to the lowest quartile of WWI, the top quartile exhibited a significantly increased risk of CVD (odds ratio [OR] = 1.883; 95% confidence interval [CI]: 1.276-2.633, p-value = 0.001), HF (OR = 2.909; 95% CI: 1.490-5.677, p-value = 0.002), CVD mortality (hazard ratio [HR] = 2.088; 95% CI: 1.279-3.409, p-value = 0.003), and all-cause mortality (HR = 1.394; 95% CI: 1.070-1.816, p-value = 0.014) among individuals with MetS. Sensitivity and subgroup analyses substantiated the consistency and stability of these associations across various demographic groups. The ROC analysis demonstrated that WWI outperforms BMI in predicting adverse outcomes in MetS. The KM curves validated that higher WWI values was correlated with diminished survival rates in MetS population. The WWI served as a significant indicator for assessing the risk of CVD and mortality in the MetS population. This study recommended the regular assessment of WWI in MetS individuals for evaluating their risk of CVD and mortality, potentially enhancing preventive and treatment strategies for this patient population.

Comparative analysis of body mass index and obesity-related anthropometric indices for mortality prediction: a study of the Namwon and Dong-gu cohort in Korea

OBJECTIVES

This study investigated the associations between several obesity-related anthropometric indices and mortality in middle-aged and elderly populations to compare the indices' predictive ability with that of the body mass index (BMI).

METHODS

We analyzed data on 12 indices calculated from 19,805 community-based cohort participants (average age, 63.27 years; median follow-up, 13.49 years). Each index was calculated using directly measured values of height, weight, waist circumference (WC), and hip circumference (HC). We calculated hazard ratios (HRs) and 95% confidence intervals (CIs) for each index using Cox regression and evaluated mortality prediction with the Harrell concordance index (c-index).

RESULTS

Adding anthropometric indices to the basic mortality model (c-index, 0.7723; 95% CI, 0.7647 to 0.7799) significantly increased the predictive power of BMI (c-index, 0.7735; 95% CI, 0.7659 to 0.7811), a body shape index (ABSI; c-index, 0.7735; 95% CI, 0.7659 to 0.7810), weight-adjusted waist index (WWI; c-index, 0.7731; 95% CI, 0.7656 to 0.7807), and waist to hip index (WHI; c-index, 0.7733; 95% CI, 0.7657 to 0.7809). The differences between the BMI model and the other 3 models were not statistically significant.

CONCLUSIONS

In predicting all-cause mortality, the ABSI, WWI, and WHI models based on WC or HC had stronger predictive power than conventional risk factors but were not significantly different from the BMI model.

Association between weight-adjusted waist index and testosterone deficiency in adult American men: findings from the national health and nutrition examination survey 2013-2016

BACKGROUND

Testosterone deficiency (TD) and obesity are globally recognized health concerns, with a bidirectional causal relationship between them. And a newly discovered obesity indicator, the Weight-Adjusted-Waist Index (WWI), has been proposed, demonstrating superior adiposity identification capability compared to traditional body mass index (BMI) and waist circumference (WC) indicators. Therefore, we present the inaugural investigation into the associations of WWI with total testosterone levels and the risk of TD.

METHODS

Data restricted to the National Health and Nutrition Examination Survey (NHANES) between 2013 and 2016 were analyzed. Only males aged > 20 years who completed body measures and underwent serum sex hormone testing were potentially eligible for analysis. Weighted multivariable linear regression and logistic regression analyses were employed to investigate the relationships between WWI and total testosterone levels, and the risk of TD, respectively. Smooth curve fittings and weighted generalized additive model (GAM) regression were conducted to examine the linear relationship among them. Additionally, subgroup analyses with interaction tests were performed to assess the stability of the results.

RESULTS

Finally, a total of 4099 participants with complete data on testosterone and WWI were included in the formal analysis. The mean age of study participants was 46.74 ± 0.35 years with a TD prevalence of 25.54%. After adjusting all potential confounders, the continuous WWI displayed a negative linear relationship with total testosterone levels (β=-61.41, 95%CI: -72.53, -50.29, P < 0.0001) and a positive linear relationship with risk of TD (OR = 1.88, 95%CI: 1.47, 2.39, P < 0.0001). When WWI was transformed into quartiles as a categorical variable, participants in Q4 exhibited lower total testosterone levels (β=-115.4, 95%CI: -142.34, -88.45, P < 0.0001) and a higher risk of TD (OR = 3.38, 95% CI: 2.10, 5.44, P < 0.001). These associations remained stable in subgroup analyses without significant interaction (all P for interaction > 0.05).

CONCLUSIONS

This investigation firstly unveiled a negative linear association between WWI and total testosterone levels, coupled with a positive linear relationship with the prevalence of TD in U.S. male adults aged 20 years and older. Further studies are needed to validate the potential utility of WWI for the early identification and timely intervention of TD.

Association between weight-adjusted-waist index and depression: a cross-sectional study

Background

Depression has become a multifaceted global health issue, with complex connections to obesity. Weight-adjusted-waist index (WWI) can effectively evaluate central obesity, but the relationship between WWI and depression has not been well studied. The study aims to investigate the potential correlation between these two health parameters.

Methods

According to the data from National Health and Nutrition Examination Survey, this cross-sectional study used multiple regression analysis, subgroup analysis, and smooth curve fitting to explore the relationship between WWI and depression. The assessment ability of WWI was evaluated and compared to other obesity indicators using the receiver operating characteristic (ROC) curve.

Results

This study analyzed 38,154 participants. Higher WWI is associated with higher depression scores (β = 0.41; 95% CI, 0.36-0.47). After adjusting for various confounding factors, the positive correlation between WWI and depression remained significant (P for trend < 0.0001). Nonlinear positive correlation was detected with a breakpoint of 11.14. ROC analysis shows that compared to other obesity indicators (ROCWWI = 0.593; ROCBMI = 0.584; and ROCWC = 0.581), the correlation between WWI and depression has better discrimination and accuracy. DII mediated 4.93%, SII mediated 5.08%, and sedentary mediated 0.35% of the total association between WWI and depression.

Conclusion

WWI levels were related to an increased likelihood of depression and showed a stronger relationship than BMI and waist circumference. Our findings indicated that WWI may serve as a simple anthropometric index to evaluate depression.

The association between weight-adjusted-waist index and stress urinary incontinence in female adults: a population-based study

INTRODUCTION

Obesity has a significant impact on female stress urinary incontinence. The weight-adjusted-waist index (WWI), a newly explored metric for measuring physical obesity and stress urine incontinence, has not been investigated.

METHODS

Cross-sectional data were obtained from the 2011 to 2018 National Health and Nutrition Examination Survey (NHANES) of participants with complete data for WWI and SUI. The independent connection between WWI and SUI was examined using weighted multivariable logistic regression analyses. Smoothed curve fitting was used to study their relationship. In addition, subgroup analyses were performed, and interaction tests were undertaken.

RESULTS

In 2,361 female participants over 20, WWI and SUI showed a positive association. Model 3 found that for each one-unit increase in WWI, SUI prevalence increased by 38% [1.38 (1.20, 1.59)]. The prevalence of SUI was 84% higher among participants in the highest quartile of WWI compared to those in the lowest quartile [1.84 (1.32, 2.57)]. Observed nonlinear positive correlation between WWI and SUI was revealed through smoothed curve fitting. In addition, we found that WWI was more strongly associated with SUI than traditional indicators of obesity, including BMI and weight.

CONCLUSIONS

Females with higher weight-adjusted waist index levels were more likely to develop stress urinary incontinence and have a stronger correlation than traditional indicators of obesity. According to our research, WWI may help detect women's stress urinary incontinence (SUI), and managing obesity through the WWI index may reduce SUI prevalence rates.

Association between the weight-adjusted waist index and the odds of type 2 diabetes mellitus in United States adults: a cross-sectional study

Objective

To examine the association between the weight-adjusted waist index (WWI) and the odds of type 2 diabetes mellitus(T2DM)among U.S. adults.

Methods

Data from the National Health and Nutrition Examination Survey (NHANES) spanning six years (2007-2018) were utilized, encompassing 31001 eligible participants. Weighted multivariate logistic regression models and smoothed fit curves were employed to assess the association between WWI and the odds of T2DM, as well as dose-response relationships in the overall population and the odds of T2DM in various subgroups.

Results

In the fully adjusted continuous model, each one-unit increase in WWI was associated with a 1.14-fold increase in the odds of T2DM within the entire study population (2.14 [1.98,2.31], P < 0.0001). In the fully adjusted categorical model, when using the lowest tertile of WWI (T1) as the reference group, the second tertile (T2) and the third tertile (T3) were associated with a 0.88-fold (1.88 [1.64,2.17], P < 0.0001) and a 2.63-fold (3.63 [3.11,4.23], P < 0.0001) increase in the odds of T2DM. These findings indicated a positive correlation between WWI values and the odds of T2DM, aligning with the results of the smoothed-fitted curves. In the analysis of subgroups, in addition to maintaining consistency with the overall population results, we found interactions between age and hypertension subgroups.

Conclusion

In conclusion, WWI was found to be positively associated with the odds of T2DM in U.S. adults.

The relationship between weight-adjusted-waist index and total bone mineral density in adults aged 20-59

Introduction

According to reports, obesity has a significant impact on bone health. And the weight-adjusted-waist index (WWI), superior to BMI and waist circumference (WC), is a new obesity indicator arising in recent years. This research investigated the relationship between WWI and total bone mineral density (BMD) for adults aged 20 to 59.

Methods

Using data from the 2011-2018 NHANES, we looked into the independent link between WWI and total BMD as well as its nonlinearity using weighted multiple linear regression and smooth curve fitting. Two-stage linear regression models were employed to calculate the threshold effects. There were additional subgroup analyses and testing for interactions.

Results

Multiple linear regression studies on a total of 10,372 individuals showed a significant inverse link between WWI and total BMD in adults between 20 and 59 [β = -0.04, 95% CI: (-0.04, -0.03), P<0.0001]. And smoking, race, and chronic kidney disease (CKD) had no significant effect on this negative connection (P for interaction >0.05). In addition, we found a nonlinear relationship between WWI and total BMD in diabetic and CKD patients, for which the saturation point was 11.38 cm/√kg in the CKD patient group and 10.29 cm/√kg in the diabetic patient group.

Conclusion

Our analysis demonstrated a significant inverse association between WWI and total BMD in adults aged 20-59.