Age-specific reference values for low psoas muscle index at the L3 vertebra level in healthy populations: A multicenter study

Ming Kong; Ning Lin; Lili Wang; Nan Geng; Manman Xu; Shanshan Li; Wenyan Song; Ying Zhou; Yuetong Piao; Zuoqing Han; Rong Guo; Chao Yang; Nan Luo; Zhong Wang; Quanxiao Xu; Daimeng Shi; Wanchun Qiu; Junfeng Li; Eddie C Cheung; Lei Ma; Yu Chen; Zhongping Duan

doi:10.3389/fnut.2022.1033831

Age-specific reference values for low psoas muscle index at the L3 vertebra level in healthy populations: A multicenter study

Front Nutr. 2022 Dec 16:9:1033831. doi: 10.3389/fnut.2022.1033831. eCollection 2022.

Authors

Ming Kong¹, Ning Lin¹, Lili Wang², Nan Geng¹, Manman Xu¹, Shanshan Li¹, Wenyan Song³, Ying Zhou⁴, Yuetong Piao⁵, Zuoqing Han⁵, Rong Guo⁵, Chao Yang⁶, Nan Luo⁷, Zhong Wang², Quanxiao Xu², Daimeng Shi², Wanchun Qiu⁸, Junfeng Li⁹, Eddie C Cheung^{10

11}, Lei Ma⁷, Yu Chen¹, Zhongping Duan¹

Affiliations

¹ Beijing Municipal Key Laboratory of Liver Failure and Artificial Liver Treatment Research, Fourth Department of Liver Disease, Beijing Youan Hospital, Capital Medical University, Beijing, China.
² Diagnosis and Treatment Center of Hepatobiliary Diseases, Nanyang First People's Hospital, Nanyang, China.
³ Department of Radiology, Beijing Youan Hospital, Capital Medical University, Beijing, China.
⁴ Department of Gastroenterology and Hepatology, The Chinese People's Liberation Army Rocket Force Characteristic Medical Center, Postgraduate Training Base of Jinzhou Medical University, Beijing, China.
⁵ Department of Infection, Dalian Medical University, Dalian, China.
⁶ Department of Radiology, The Second Hospital of Dalian Medical University, Dalian, China.
⁷ Department of Infection, The Second Hospital of Dalian Medical University, Dalian, China.
⁸ Department of Infection, The First Clinical Medical School of Lanzhou University, Lanzhou, China.
⁹ Department of Infectious Diseases, Institute of Infectious Diseases, The First Hospital of Lanzhou University, Lanzhou, China.
¹⁰ Division of Gastroenterology, School of Medicine, University of California, Davis, Davis, CA, United States.
¹¹ Center for Digestive Disease, The Seventh Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.

Abstract

Background and aims: The progressive and generalized loss of skeletal muscle mass, strength and physical function is defined as sarcopenia. Sarcopenia is closely related to the prognosis of patients. Accurate diagnosis and adequate management of sarcopenia are crucial. The psoas muscle mass index taken at the third lumbar vertebra (L3-PMI, cm²/m²) is one of the established methods for evaluating skeletal muscle mass. However, the cutoff values of L3-PMI for diagnosis of sarcopenia are not yet to be clarified in Asian populations. We attempted to establish reference values for low L3-PMI that would be suitable for defining sarcopenia in the Northern Chinese population.

Methods: This was a retrospective, multicenter cross-sectional study. A search of abdominal CT imaging reports was conducted in four representative cities in northern China. Transverse CT images were measured using the analysis software Slice-O-Matic. Low psoas muscle index was defined as the 5th percentile or mean-2SD of the study group.

Results: 1,787 healthy individuals in the study were grouped by age. The sex and number of people in each group were similar. L3-PMI had a negative linear correlation with age, and a strong correlation with the skeletal muscle index taken at the third lumbar vertebrae (L3-SMI, cm²/m²). The L3-PMI reference values in males were 5.41 cm²/m² for 20-29 years, 4.71 cm²/m² for 30-39 years, 4.65 cm²/m² for 40-49 years, 4.10 cm²/m² for 50-59 years and 3.68 cm²/m² for over 60 years by using 5th percentile threshold. Similarly, the reference values in females were 3.32, 3.40, 3.18, 2.91, and 2.62 cm²/m². When using mean-2SD as the reference, the values for each age group were 4.57, 4.16, 4.03, 3.37, and 2.87 cm²/m² for males and 2.79, 2.70, 2.50, 2.30, and 2.26 cm²/m² for females, respectively.

Conclusion: We defined the reference values of age-specific low skeletal muscle mass when simply evaluated by L3-PMI. Further studies about the association of sarcopenia using these reference values with certain clinical outcomes or diseases are needed.

Keywords: computed tomography; healthy adults; lumbar 3 vertebra; reference values; sarcopenia; skeletal muscle mass.

Grants and funding

This study was supported by Beijing Advanced Innovation Center for Big Data-Based Precision Medicine (PXM2021_014226_000026) and Capital’s Funds for Health Improvement and Research (2021-1G2181).