Effect of Body Composition on Supine Pressure Distribution in Bed: A Comparison Between Young and Older Adults

Pressure ulcers are a serious concern in older adults and are often caused by uneven pressure distribution in the supine position. While body mass index is commonly used in risk assessments, it may not reflect localized body pressure. Exploring the relationship between body composition and pressure distribution may help guide individualized prevention strategies.

To investigate how body composition influences supine pressure distribution across different body regions and to clarify whether these associations differ between healthy young and older adults.

The mean body pressures in the whole body, upper body, buttocks, and heels were measured using a pressure distribution device (SR Soft Vision, Sumitomo Riko Company Limited, Japan) placed on a pressure-relieving mattress commonly used in clinical settings. Body composition was assessed using a multi-frequency bioelectrical impedance analyzer (InBody S10, InBody Japan Inc., Japan) to obtain body mass index (BMI), skeletal muscle index (SMI), and fat mass index (FMI). Correlation and multiple regression analyses were performed to examine these associations.

Upper-body pressure was significantly higher in older adults, whereas buttock pressure was higher in younger adults. The SMI was significantly associated with body pressure in the younger age group. The FMI was significantly associated with body pressure in the older age group.

Body composition influenced pressure distribution in a region-specific and age-dependent manner. These findings may contribute to the prevention of pressure ulcers and the development of individualized pressure management strategies.