# The Association Between Weight‐Adjusted‐Waist Index and S‐Klotho Levels in Adults: NHANES 2007–2016

## TL;DR

This study finds that a new obesity measure called WWI is negatively linked to serum Klotho levels, a biomarker of aging, suggesting WWI could help identify individuals at higher risk for aging-related health issues.

## Contribution

The study introduces WWI as a novel obesity metric and demonstrates its significant negative association with serum Klotho levels.

## Key findings

- WWI shows a significant negative correlation with serum Klotho levels across all demographic subgroups.
- Participants in the highest WWI quartile had notably lower serum Klotho levels compared to those in the lowest quartile.
- The association suggests WWI could be a practical clinical indicator for identifying individuals at risk of accelerated aging.

## Abstract

The weight‐adjusted waist index (WWI) is a new obesity metric that may better reflect body fat distribution than traditional measures like body mass index (BMI). However, the link between WWI and serum Klotho levels, an aging biomarker, is not well understood. The study involved non‐pregnant adults aged 40 to 79 years who had comprehensive data regarding BMI, waist circumference (WC), and serum Klotho levels. We analyzed data from 12,809 participants aged 40 to 79 years from NHANES. WWI was calculated by dividing WC by the square root of body weight. Participants were categorized into quartiles based on WWI values. A multivariate linear regression model assessed the relationship between WWI and serum Klotho levels, with subgroup analyses for demographic consistency. The analysis showed a significant negative correlation between WWI and serum Klotho levels (β = −24.75, 95% CI: −24.84, −24.66). Participants in the highest WWI quartile had lower serum Klotho levels than those in the lowest quartile (β = −27.88, 95% CI: −28.03, −27.73). This negative association was consistent across all subgroups, including age, gender, diabetes status, hypertension status, and BMI categories. Our findings indicate a significant negative association between WWI and serum Klotho concentrations, suggesting that WWI may be a practical clinical indicator for identifying individuals at higher risk of accelerated aging and related metabolic complications. Incorporating WWI into routine assessments could help clinicians better associated with patients at risk for reduced Klotho and its associated health consequences, supporting more targeted prevention or intervention strategies. The cross‐sectional design precludes causal inference, and potential confounders such as physical activity, dietary factors, and medication use were not fully accounted for. Further longitudinal and mechanistic studies are needed to confirm these associations and clarify underlying pathways.

This study investigates the relationship between the weight‐adjusted waist index (WWI) and serum Klotho levels in adolescents, highlighting WWI as a potentially more accurate obesity indicator than traditional measures like BMI. The findings reveal a significant negative association between WWI and serum Klotho concentrations, suggesting that WWI may serve as a predictive indicator of serum Klotho levels, with implications for understanding obesity's influence on aging. Further research is needed to explore the underlying mechanisms of this relationship.