# Non-linear associations between UHR and bone mineral density in US adults: NHANES 2017–2018

## TL;DR

This study finds a non-linear link between the uric acid to HDL cholesterol ratio and bone mineral density in U.S. adults, suggesting it could be a useful biomarker for bone health.

## Contribution

The study introduces a non-linear relationship between UHR and BMD, identifying a key threshold at UHR 19.

## Key findings

- A significant inflection point was found at UHR 19, with positive association below and non-significant negative association above.
- The relationship remained significant among Mexican Americans after adjusting for covariates.

## Abstract

Bone mineral density (BMD) is a key indicator of bone health, particularly in older populations, where lower BMD is linked to increased risk of osteoporosis and fractures. Metabolic factors like serum uric acid (UA) and high-density lipoprotein cholesterol (HDL-C) have emerged as possible determinants of bone health. The uric acid to HDL cholesterol ratio (UHR) may offer a new perspective on these metabolic influences. This study explores the association between UHR and femoral neck BMD, with a focus on non-linear relationships and subgroup variations by body mass index (BMI), age, and sex.

The study used data from 2178 participants from the 2017–2018 National Health and Nutrition Examination Survey (NHANES). UHR was calculated as the ratio of serum UA to HDL-C. BMD measurements were obtained using dual-energy X-ray absorptiometry (DXA) at the femoral neck. A two-piecewise linear regression model was applied to examine the non-linear relationship between UHR and BMD. Stratified analyses were conducted by BMI, gender, and age groups.

A significant inflection point was found at UHR 19. Below this threshold, UHR was positively associated with femoral neck BMD (β = 0.0054, p = 0.013), while above the threshold, the association was negative but not statistically significant (β = − 0.0016, p = 0.478). Stratified analysis revealed that the relationship between UHR and BMD remained significant among Mexican Americans even after adjusting for covariates (β = 0.0145, p = 0.012).

This study identifies a non-linear association between UHR and femoral neck BMD, with a key inflection point at UHR 19. These findings suggest that UHR could be a useful biomarker for bone health, especially in populations with higher metabolic risks. Further longitudinal studies are necessary to establish causality and explore potential interventions targeting UHR to improve bone health.