# Association Between Weight‐Adjusted Waist Index and Depressive Symptoms Among Middle‐Aged and Older Adults: Evidence From Two Prospective Longitudinal Cohort Studies

## TL;DR

This study shows that a higher weight-adjusted waist index is linked to a greater risk of depression in middle-aged and older adults.

## Contribution

The study introduces the weight-adjusted waist index as a novel predictor of depression risk in longitudinal analyses.

## Key findings

- Participants in the highest quartile of WWI had a 33% higher risk of depression.
- A positive linear association between WWI and depression risk was confirmed using regression models.
- WWI may serve as a target for interventions to reduce depression in older adults.

## Abstract

The association between obesity and depression has been debated. This study aimed to explore the long‐term relationship between the weight‐adjusted waist index (WWI) and depression in different ethnic groups.

This prospective cohort study analyzed data from English Longitudinal Study on Aging (ELSA) and Health and Retirement Study (HRS). The exposure variable was the WWI at baseline, calculated by dividing the waist circumference (cm) by the square root of weight (kg). Depressive symptoms were assessed using the CESD‐8. The longitudinal relationship between WWI and depression was analyzed using Cox proportional hazards and restricted cubic spline (RCS) regression models.

During the 12‐year follow‐up period, depressive symptoms were observed in 55.1% of HRS patients (1851/3359) and 54.8% of ELSA patients (1810/3303). In fully adjusted Cox regression analysis, participants in the 4th quartile of the WWI exhibited a 33% elevated risk of depression (HR = 1.33, 95% CI: 1.15–1.54). Furthermore, the fully adjusted RCS regression model revealed a positive linear association between WWI and the risk of depression.

Our studies demonstrated a positive linear correlation between WWI and elevated risk of depression. Alterations in WWI have the potential to predict the occurrence of depression in middle‐aged and elderly individuals.

Our results point to the importance of the WWI in predicting the risk of depression in middle‐aged and older adults. In future intervention wording, WWI may become a target to reduce the high prevalence of depression in middle‐aged and older adults. Image was created in BioRender. Liu, G. (2024) https://BioRender.com/e47a501.