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

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. 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. 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). 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.

Liu D ，Li Y ，Ji N ，Xia W ，Zhang B ，Feng X ... -  《BMC PUBLIC HEALTH》

Association between cardiometabolic index and risk of testosterone deficiency in adult men: a cross-sectional study.

Metabolic health is closely related to testosterone levels, and the cardiometabolic index (CMI) is a novel metabolic evaluation metric that encompasses obesity and lipid metabolism. However, there is currently a lack of research on the relationship between CMI and testosterone, which is the objective of this study. This study utilized data from the National Health and Nutrition Examination Survey (NHANES) cycles from 2011 to 2016. Only adult males who completed physical measurements, lipid metabolism assessments, and testosterone measurements were included in the final analysis. The exposure variable CMI was analyzed both as a continuous variable and a categorical variable divided into quartiles. Testosterone was measured using the isotope dilution liquid chromatography-tandem mass spectrometry technique. Linear and logistic regression analyses were used to explore the relationship between CMI and total testosterone (TT) levels, as well as the risk of testosterone deficiency (TD). Smooth curve fittings were employed to visualize their linear relationships. Subgroup analyses were conducted to evaluate the stability of our results across different participant characteristics. Finally, ROC analysis was used to assess the performance of CMI in predicting TD. A total of 2,747 participants were included in the analysis, including 552 with TD (20.10%). The average CMI of the sample was 1.59 ± 0.03, with TD participants having a higher CMI of 2.18 ± 0.08 compared to non-TD participants at 1.46 ± 0.03. Corresponding testosterone levels were 223.79 ± 3.69 ng/dL and 508.36 ± 5.73 ng/dL, respectively. After adjusting for all covariates, participants with higher CMI showed lower TT (β = -23.84, 95% CI: -33.94, -13.74, p < 0.0001) and a higher risk of TD (OR = 1.26, 95% CI: 1.08, 1.48, p = 0.01). When CMI was categorized into quartiles with Q1 as the reference, participants in Q4 exhibited significantly lower TT (β = -74.04, 95% CI: -106.01, -42.08, p < 0.0001) and a higher risk of TD (OR = 2.34, 95% CI: 1.18, 4.64, p = 0.02). Smooth curve fittings indicated a linear relationship between these variables. Subgroup analyses confirmed the stability of these associations across different population characteristics. ROC curve analysis demonstrated that CMI had good predictive performance for TD with a cut-off value of 1.126 and an AUC (95% CI) of 0.673 (0.649, 0.700). CMI is associated with lower TT and a higher risk of TD, and it can predict the risk of TD. Using CMI for early detection and timely intervention could reduce the disease burden and promote reproductive health. Further prospective studies with large sample sizes are needed to validate these findings.

Mei Y ，Zhang B ，Wang X ，Xu R ，Xia W ，Chen Y ，Feng X ... -  《BMC PUBLIC HEALTH》

Association between four anthropometric indices with age-related Macular Degeneration from NHANES 2005-2008.

Age-related macular degeneration (AMD) decrease vision and presents considerable challenges for both public health and clinical management strategies. Obesity is usually implicated with increased AMD, and body mass index (BMI) does not reflect body fat distribution. An array of studies has indicated a robust relationship between body fat distribution and obesity. This research is to evaluate the relationship between anthropometric measurements and AMD in the United States citizens in a cohort of patients. Our study included a cohort of 3,127 participants, all of whom were selected from the National Health and Nutrition Examination Survey (NHANES) conducted between 2005 and 2008. Various anthropometric indices, including weight (WT), waist circumference (WC), Body Mass Index (BMI), waist-to-height ratio (WtHR), circularity index (CI), weight-adjusted waist circumference index (WWI), body roundness index (BRI), a body size index (ABSI), and visceral adiposity index (VAI), have been studied extensively within public health and nutrition to assess body fat distribution. Odds ratios (OR) for each anthropometric index, in relation to AMD and its different stages, were computed, adjusting for confounding variables. Smoothed curve fitting, coupled with weighted multivariable logistic regression analysis, was used to examine the impact of these anthropometric measures on the prevalence of AMD. Subgroup analyses were conducted according to gender, age, BMI, drinking, smoking, CVD, diabetes, hypertension, cataract operation, and glaucoma. After adjusting for all variables, significant positive correlations were observed between WtHR (OR = 1.237 (1.065-1.438)), BRI (OR = 1.221 (1.058-1.410)), CI (OR = 1.189 (1.039-1.362)), and WWI (OR = 1.250 (1.095-1.425)) with AMD, particularly for early AMD. However, no significant effects of these indicators were observed in late AMD. CI exhibited a positive linear relationship with AMD. Two-segment linear regression modeling revealed positive nonlinear associations between WtHR, BRI, and WWI with AMD. The positive association was more pronounced with excessive alcohol consumption for WtHR, BRI, CI, and WWI (P for interaction = 0.0033, 0.0021, 0.0194, and 0.0022, respectively). Additionally, WWI and CI exhibited stronger associations with AMD in females (P for interaction = 0.0146 and 0.0117, respectively). Furthermore, WtHR was associated with AMD in non-smokers (P for interaction = 0.0402). This study confirmed a increased risk between four anthropometric measures, including WtHR, BRI, CI, and WWI, with AMD, especially early AMD. The findings suggest that these four anthropometric indices should be more broadly utilized to improve early AMD prevention and treatment strategies. Additionally, we found that the positive association between these four body measurement indices and AMD was more pronounced in individuals with high alcohol consumption.

Xu C ，Wu X 《Lipids in Health and Disease》

Weight-adjusted-waist index: an innovative indicator of breast cancer hazard.

Central obesity and breast cancer (BC) have been identified as relevant by empirical research. The weight-adjusted-waist index (WWI) is a novel methodology for quantifying central obesity. Inspection of the association between WWI and BC in American adult women was the primary goal of the current investigation. Cross-sectional assessments were conducted on information gathered from 10,193 National Health and Nutrition Examination Survey (NHANES) participants from 2011 to 2018. The waist circumference was divided by the square root of the body's mass to compute WWI. Data were assessed via descriptive statistics to present data distributions according to BC grouping and WWI grouping, receiver operating characteristic curves (ROCs) to evaluate the obesity indicators' applied value, logistic regression to reflect associations between WWI and BC prevalence, and restricted cubic splines (RCSs) and subgroup analysis forest plots to visualise and complement the relationships. This study enrolled 10,193 participants whose WWI ranged from 8.38 to 14.41, 259 of whom were diagnosed with BC, and the results revealed significant differences in baseline characteristics between the groups. With an area under the curve (AUC) value (95% confidence interval) (CI)of 0.611 (0.577-0.644), WWI was a promising indicator of BC with good application value rather than waist circumference (WC), body mass index (BMI), or waist-height ratio (WHtR). WWI and BC laid out a substantial relationship, yielding an odds ratio (OR) of 1.54 and a 95% CI of (1.34, 1.79), which remained at 1.19 (1.00, 1.42) after considerable adjustments were made, according to the logistic regression analysis. Compared with the lowest quartile of WWI, the highest quartile had a 62% greater in the probability of suffering from BC. With the RCS's inverted U-shape highlighting the importance of considering the nonlinear nature of the relationship and subgroup analyses reflecting variations among populations, all the results demonstrated that WWI was a well-suggestive indicator of BC hazard. The current investigation revealed a meaningful association between the prevalence of BC and WWI, which was superior to other obesity indicators, albeit one that was more complex than the positive relationship initially derived. There existed a turning point for BC prevalence at WWI of approximately 12 cm/√kg. Nevertheless, maintaining WWI in the lower range is critical for preventing and administering BC and minimizing disease risk.

Huang X ，Cheng H ，Deng L ，Wang S ，Li J ，Qin A ，Chu C ，Du W ，Liu X ... -  《BMC Womens Health》

[Association between weight-adjusted waist index and pain: A cross-sectional study].

Liu H ，Wen B ，Bai X ，Chen M ，Li M ... -  《-》