Obesity is associated with muscle atrophy in rotator cuff tear

Simone D Herzberg; Zhiguo Zhao; Thomas H Freeman; Ravi Prakash; Keith M Baumgarten; Julie Y Bishop; James L Carey; Grant L Jones; Eric C McCarty; Edwin E Spencer; Armando F Vidal; Nitin B Jain; Ayush Giri; John E Kuhn; Michael S Khazzam; Elizabeth G Matzkin; Robert H Brophy; Warren R Dunn; C Benjamin Ma; Robert G Marx; Sourav K Poddar; Matthew V Smith; Brian R Wolf; Rick W Wright

doi:10.1136/bmjsem-2024-001993

Obesity is associated with muscle atrophy in rotator cuff tear

BMJ Open Sport Exerc Med. 2024 Jun 28;10(2):e001993. doi: 10.1136/bmjsem-2024-001993. eCollection 2024.

Authors

Simone D Herzberg^{1

2}, Zhiguo Zhao³, Thomas H Freeman⁴, Ravi Prakash⁵, Keith M Baumgarten⁶, Julie Y Bishop⁷, James L Carey⁸, Grant L Jones⁷, Eric C McCarty⁹, Edwin E Spencer¹⁰, Armando F Vidal¹¹, Nitin B Jain¹², Ayush Giri¹³, John E Kuhn¹⁴, Michael S Khazzam¹⁵, Elizabeth G Matzkin¹⁶, Robert H Brophy¹⁷, Warren R Dunn¹⁸, C Benjamin Ma¹⁹, Robert G Marx²⁰, Sourav K Poddar⁹, Matthew V Smith¹⁷, Brian R Wolf²¹, Rick W Wright¹⁴

Affiliations

¹ Epidemiology, Vanderbilt University, Nashville, Tennessee, USA.
² School of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA.
³ Department of Biostatistics, Vanderbilt University Medical Center, Nashville, Tennessee, USA.
⁴ Great Lakes Orthopaedic Center, Traverse City, Michigan, USA.
⁵ Departments of Physical Medicine and Rehabilitation, University of Michigan, Ann Arbor, Michigan, USA.
⁶ Orthopedic Institute of Sioux Falls, Sioux Falls, South Dakota, USA.
⁷ Departments of Orthopaedic Surgery and Sports Medicine, Ohio State University, Columbus, Ohio, USA.
⁸ Department of Orthopaedic Surgery, Perelman School of Medicine, Philadelphia, Pennsylvania, USA.
⁹ Department of Orthopedic Sports Medicine, University of Colorado Denver, Denver, Colorado, USA.
¹⁰ Shoulder & Elbow Division, Knoxville Orthopaedic Clinic, Knoxville, Tennessee, USA.
¹¹ Steadman Philippon Research Institute, Vail, Colorado, USA.
¹² PM&R and Orthopaedics, University of Michigan-Ann Arbor, Ann Arbor, Michigan, USA.
¹³ Division of Epidemiology, Department of Medicine Division of Quantitative Sciences, Department of Obstetrics and Gynecology, Vanderbilt University Medical Center, Nashville, Tennessee, USA.
¹⁴ Orthopaedics, Vanderbilt University Medical Center, Nashville, Tennessee, USA.
¹⁵ Department of Orthopedic Surgery, The University of Texas Southwestern Medical Center, Dallas, Texas, USA.
¹⁶ Orthopedics, Brigham and Women's Hospital, Boston, Massachusetts, USA.
¹⁷ Orthopaedic Surgery, Washington University in Saint Louis School of Medicine, Chesterfield, Missouri, USA.
¹⁸ Department of Clinical Research, Fondren Orthopedic Group LLP, Houston, Texas, USA.
¹⁹ Department of Orthopedic Surgery, University of California San Francisco, San Francisco, California, USA.
²⁰ Hospital for Special Surgery, New York, New York, USA.
²¹ Orthopedics and Rehabilitation, The University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA.

Abstract

Objective: The primary goal of this study is to evaluate the relationship between Body Mass Index (BMI) and muscle atrophy in individuals with rotator cuff tears.

Methods: This study consists of patients with rotator cuff tears identified by MRI from two independent cohorts, the Rotator Cuff Outcomes Workgroup (ROW) and the Multicenter Orthopaedic Outcomes Network (MOON). Presence of atrophy (yes/no) and severity of atrophy (as an ordinal variable) were assessed on MRI by expert physicians. We used multivariable regression models to evaluate the relationship between BMI and muscle atrophy while adjusting for age and sex in each study, conducted sensitivity analyses for full-thickness tear and combined results using inverse variance-weighted meta-analysis.

Results: A total of 539 patients (MOON=395, ROW=144) from the combined cohorts had MRI data available on muscle atrophy. Among these patients, 246 (46%) had atrophy of at least one of the muscles of the rotator cuff and 282 (52%) had full-thickness tears. In meta-analysis across both cohorts, each 5 kg/m² increase in BMI was associated with a 21% (aOR=1.21, 95% CI=1.02, 1.43) increased odds of having muscle atrophy among individuals with any tear size, and 36% (aOR=1.36, 95% CI=1.01-1.81) increased odds among individuals with full-thickness tear.

Conclusions: Higher BMI was associated with significantly higher odds of muscle atrophy in patiens with rotator cuff tears. More study is needed to unders1tand why and how this relationship exists, as well as whether interventions to reduce BMI may help improve outcomes for these patients.

Level of evidence: III.

Keywords: Adaptations of skeletal muscle to exercise and altered neuromuscular activity; Muscle damage/injuries; Muscle injury and inflammation; Shoulder; Tendinopathy.

Abstract

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