# Low initial body fat percentage exacerbates skeletal muscle loss and increases the risk of hyperuricemia during high-altitude acclimatization in young men

## TL;DR

Young men with low body fat who move to high altitudes are more likely to lose muscle mass and develop high uric acid levels.

## Contribution

This study identifies initial body fat percentage and changes in skeletal muscle mass as predictors of hyperuricemia during high-altitude acclimatization.

## Key findings

- Low initial body fat percentage is associated with greater skeletal muscle mass loss at high altitude.
- Decreased skeletal muscle mass and low initial body fat percentage are independent risk factors for hyperuricemia.
- Over 60% of young men developed hyperuricemia after one year at high altitude.

## Abstract

The incidence of hyperuricemia (HUA) increases significantly after individuals ascend to a high-altitude environment, particularly among young men. Previous studies have shown correlations between skeletal muscle mass, fat mass, and serum uric acid levels. However, whether changes in body composition under high-altitude conditions influence the occurrence of HUA has not been reported.

This study aimed to investigate the effects of initial body fat percentage (BF%) and changes in body composition on the development of HUA in young men after 1 year at high altitude.

In this prospective observational study, 216 young men who relocated from a plain area to a high-altitude area for 1 year were enrolled. Data on basic information, body composition, and laboratory measurements were collected both before relocation and after the one-year period.

After 1 year at high altitude, skeletal muscle mass (SMM) decreased significantly. Linear regression analysis revealed that the change in SMM was correlated with the initial BF%; a lower initial BF% was associated with a more pronounced decrease in SMM (b = 0.186, p < 0.001). A total of 136 participants (62.96%) were diagnosed with HUA after 1 year. Binary logistic regression analysis revealed high altitude (OR = 2.217, p < 0.05), low SMM (OR = 0.920, p < 0.05), low initial BF% (4–8%: OR = 3.142, p < 0.05; ≤4%: OR = 4.489, p < 0.01), and a decrease in SMM (−1.5 to −2.5 kg: OR = 2.599, p < 0.05; ≤−2.5 kg: OR = 3.263, p < 0.05) as risk factors for HUA. After adjusting for altitude and SMM, a decrease in SMM (−1.5 to −2.5 kg: OR = 2.735, p < 0.05; ≤−2.5 kg: OR = 3.198, p < 0.05) and low initial BF% (4–8%: OR = 2.687, p < 0.05; <4%: OR = 3.708, p < 0.01) remained predictive factors for HUA.

Our findings indicate that for young men moving from plains to high altitudes, the BF% and the change in SMM can be used to predict the incidence of hyperuricemia after 1 year.