Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2025 Oct;16(5):e70099.
doi: 10.1002/jcsm.70099.

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

Elizabeth Benz  1   2 , Alexandre Pinel  1 , Christelle Guillet  1 , Frederic Capel  1 , Bruno Pereira  3 , Dimitris Rizopoulos  2   4 , Alfonso J Cruz-Jentoft  5 , Doris Eglseer  6 , Eva Topinkova  7 , Rocco Barazzoni  8 , Lorenzo M Donini  9 , Fernando Rivadeneira  10 , Marinka Steur  2   11 , Trudy Voortman  2 , Peter J M Weijs  12   13 , Josje D Schoufour  12 , Yves Boirie  1   14
Affiliations

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

Elizabeth Benz et al. J Cachexia Sarcopenia Muscle. 2025 Oct.

Abstract

Background: Sarcopenic obesity (SO) is a clinical condition defined by the coexistence of high body fat mass and low muscle function and mass, which increases the risk of adverse health outcomes, including disability and mortality. Early detection and frequent monitoring of SO are essential for preventive interventions and management strategies. The current binary approach for SO diagnosis is limited in capturing the spectrum of SO or its progression over time. The main objective of this study was to develop a continuous SOPi that integrates diagnostic criteria such as muscle function and body composition. We aimed to evaluate the association between SOPi and all-cause mortality, to identify baseline-related factors with SOPi and to assess changes in the SOPi over time.

Methods: Participants from the Rotterdam Study with baseline and follow-up measures of handgrip strength (HGS), dual-energy X-ray absorptiometry-measured appendicular lean mass index (ALM/kg) and body fat percentage (BF%) were included. SOPi was calculated as a sex-specific equation integrating z-scores (Z) of (BF%)-(HGS)-(ALM/kg). Cox regression and multivariable linear regression models were fitted to evaluate mortality risk and associated factors with SOPi, respectively. Subgroup analysis of SOPi changes was performed by linear mixed-effects models.

Results: In the total population (n = 5888, age 69.5 ± 9.1 years, BMI 27.5 ± 4.3 kg/m2, 56.8% females) and over the 9.9-year median follow-up period, 1538 (26.1%) participants died. Each standard deviation (SD) increase in sex-specific SOPi was associated with a 10% higher risk of premature death (HR = 1.10 [95%CI: 1.07; 1.13]). Thirteen factors were associated with high SOPi, such as reduced physical activity, higher triglyceride-glucose index, HOMA-IR, systemic inflammation, osteopenia, hypertension, liver steatosis, asthma, coronary heart disease, oral corticosteroid use, lower protein intake, lower quality of life and lower educational status. In participants with obesity, lower physical activity and/or insulin resistance (n = 1682), a significantly higher and faster increase in SOPi was observed compared to participants without these factors (males: β = 2.63 [95%CI: 2.22; 3.03]; females: β = 2.90 [95%CI: 2.58; 3.23]).

Conclusion: SOPi is a significant predictor of premature death and can identify associated factors, particularly useful among persons at risk of SO. SOPi is higher and increases faster in individuals with specific phenotypes. SOPi integrates prognosis information, which could be used as a risk indicator and for prevention of SO.

Keywords: phenotype; population‐based study; sarcopenia; sarcopenic obesity; survival.

PubMed Disclaimer

Conflict of interest statement

Elizabeth Benz, Alfonso J. Cruz‐Jentoft, Doris Eglseer, Eva Topinkova and Josje Schoufour reported receiving grants from the SO‐NUTS project, which is funded by JPI HDHL under the ERA‐NET cofund action No. 727565, outside the submitted work. Rocco Barazzoni disclosed his membership on advisory board panels for Novo Nordisk, Pfizer, Boehringer, Nutricia Research, as well as personal fees from Eli‐Lilly, unrelated to the submitted work. Yves Boirie disclosed receiving a grant from the Agence Nationale de la Recherche (ANR) during the conduct of the study and personal fees from Fresenius Kabi, Sanofi France, Novo Nordisk and Lilly outside the submitted work. Alexandre Pinel, Christelle Gillet, Frederick Capel, Bruno Pereira, Dimitris Rizopoulos, Lorenzo M. Donini, Fernando Rivadeneira, Marinka Steur, Trudy Voortman and Peter J.M. Weijs declared that they have no conflicts of interest.

Figures

FIGURE 1
FIGURE 1
Flow chart and analysis process of the study population.
FIGURE 2
FIGURE 2
Kaplan–Meier curves for survival time for all‐cause mortality in (A) the whole population (n = 5888), (B) participants without any diagnostic criteria of SO (n = 3096) and (C) participants with at least one diagnostic criteria of SO (n = 2792).
FIGURE 3
FIGURE 3
Association between SOPi and all‐cause mortality in (a) all population and (b) population without SO.
FIGURE 4
FIGURE 4
Heat map visualization of clinical and lifestyle factors associated with sex‐specific SOPi and its components in all population (n = 5888).
See this image and copyright information in PMC

References

    1. Donini L. M., Busetto L., Bischoff S. C., et al., “Definition and Diagnostic Criteria for Sarcopenic Obesity: ESPEN and EASO Consensus Statement,” Obesity Facts 15, no. 3 (2022): 321–335. - PMC - PubMed
    1. Donini L. M., Busetto L., Bischoff S. C., et al., “Definition and Diagnostic Criteria for Sarcopenic Obesity: ESPEN and EASO Consensus Statement,” Clinical Nutrition 41, no. 4 (2022): 990–1000. - PubMed
    1. Benz E., Pinel A., Guillet C., et al., “Sarcopenia and Sarcopenic Obesity and Mortality Among Older People,” JAMA Network Open 7, no. 3 (2024): e243604‐e. - PMC - PubMed
    1. Morikawa M., Lee S., Makino K., et al., “Sarcopenic Obesity and Risk of Disability in Community‐Dwelling Japanese Older Adults: A 5‐Year Longitudinal Study,” Journal of the American Medical Directors Association 24, no. 8 (2023): 1179–1184.e1. - PubMed
    1. Cancello R., Brenna E., Soranna D., et al., “Sarcopenia Prevalence Among Hospitalized Patients With Severe Obesity: An Observational Study,” Journal of Clinical Medicine 13, no. 10 (2024): 2880. - PMC - PubMed