Sarcopenic Obesity Phenotype Index (SOPi): A Population-Based Study

Area of Science:

• Gerontology
• Metabolic Health
• Body Composition Analysis

Background:

• Sarcopenic obesity (SO) combines high body fat with low muscle mass/function, increasing mortality risk.
• Current diagnostic methods for SO are binary and limit tracking disease progression.
• Early detection and monitoring are crucial for managing SO and preventing adverse outcomes.

Purpose of the Study:

• To develop a continuous Sarcopenic Obesity Prognostic Index (SOPi) integrating muscle function and body composition.
• To assess the association between SOPi and all-cause mortality.
• To identify factors related to baseline SOPi and track changes over time.

Main Methods:

• Utilized data from the Rotterdam Study, including handgrip strength (HGS), appendicular lean mass index (ALM/kg), and body fat percentage (BF%).
• Calculated SOPi using a sex-specific equation integrating z-scores of BF%, HGS, and ALM/kg.
• Employed Cox regression and linear mixed-effects models to analyze mortality risk, associated factors, and SOPi changes.

Main Results:

• Each SD increase in SOPi correlated with a 10% higher risk of premature death (HR=1.10).
• Thirteen factors, including reduced physical activity, insulin resistance, and inflammation, were linked to high SOPi.
• Participants with obesity and factors like low physical activity or insulin resistance showed a faster SOPi increase.

Conclusions:

• SOPi effectively predicts premature death and identifies associated risk factors, especially in individuals at risk for SO.
• SOPi demonstrates higher values and faster progression in specific phenotypes.
• The SOPi serves as a valuable prognostic indicator for SO risk assessment and prevention strategies.