# Secular trends in grip strength among Korean adults according to socioeconomic factors: the 2014-2022 Korea National Health and Nutrition Examination Survey

## TL;DR

This study shows that grip strength in Korean adults declined from 2014 to 2022, with lower socioeconomic groups experiencing the biggest drops.

## Contribution

The study identifies socioeconomic disparities in grip strength trends using a nationally representative dataset from 2014 to 2022.

## Key findings

- Mean grip strength decreased significantly in both males and females from 2014 to 2022.
- Individuals with lower education and income levels had notably lower grip strength in 2022.
- Unemployed individuals and those in certain occupational groups showed reduced grip strength compared to higher socioeconomic groups.

## Abstract

Muscle strength is a key indicator of overall health, and its decline has been linked to increased morbidity and mortality. Socioeconomic factors may contribute to disparities in this decline. Therefore, this study aimed to examine trends in muscle strength and to identify groups with lower muscle strength according to socioeconomic variables.

We analyzed data from the cross-sectional Korea National Health and Nutrition Examination Survey (KNHANES), including 34,080 adults. Multivariable linear regression analyses were conducted, adjusting for socioeconomic and health-related covariates, and KNHANES survey weights were applied to obtain nationally representative estimates that accounted for the complex sampling design.

Overall, mean grip strength significantly decreased from 2014 to 2022 in both males (from 43.45±0.24 to 41.59± 0.29 kg) and females (from 26.48±0.15 to 24.94±0.13 kg). This trend was consistently observed across all covariate strata, except for individuals aged over 70 years and those in the green-collar occupational group. In 2022, grip strength was lower among individuals with the lowest education level (26.45±0.34 vs. 34.75±0.32 kg in the undergraduate group) and the lowest household income level (29.59±0.45 vs. 34.53±0.35 kg in the highest income group), as well as among unemployed individuals (29.36± 0.30 vs. 37.00±0.47 kg in the blue-collar group), compared with their higher socioeconomic counterparts.

These findings provide descriptive evidence of grip strength trends and socioeconomic disparities in Korea. They may serve as baseline information to guide future longitudinal studies and inform public health strategies.