# Pectoral muscle cross-sectional area correlates with bone mineral density in postmenopausal women

## TL;DR

This study found that pectoral muscle size in postmenopausal women is linked to bone density, suggesting muscle mass could help assess osteoporosis risk.

## Contribution

The study introduces pectoral muscle cross-sectional area as a novel indicator for estimating bone mineral density in postmenopausal women.

## Key findings

- Pectoral muscle area was positively correlated with the lowest bone mineral density (r = 0.448).
- A formula was developed to estimate lowest BMD using age, BMI, and pectoral muscle area.
- Reduced muscle mass is associated with increased osteoporosis risk.

## Abstract

To evaluate the correlation between pectoralis muscle and bone mineral density (BMD) in postmenopausal women with estrogen deficiency. Furthermore, the degree of bone loss can be initially assessed by chest muscle area.

This is a retrospective study. 500 subjects were included in this study from August 2023 to August 2024. The participants were classified into normal, osteopenia, and osteoporosis groups. We analyzed the correlation between the age, BMI, PMA and BMD. The correlation between PMA and BMD was tested by multiple linear regression, after correction for age and BMI.

A total of 338 subjects were finally included in the study after exclusion criteria. There was good agreement between the two measurement workers (ICC = 0.980, p < 0.05). Age, BMI and PMA were strongly correlated with BMD. PMA was positively correlated with lowest BMD (r = 0.448). Multiple linear regression showed no multicollinearity between age, BMI and PMA. The formula was: Lowest BMD = 0.858 – 0.005 * age + 0.006 * BMI + 0.005 * PMA.

Decreased muscle mass increases the risk of osteoporosis prevalence. Simple measurements from routine chest CT can provide information about BMD and offer a way to evaluate osteoporosis.