3 Reasons GLP-1 Care Must Consider the Entire MSK System, Not Just Muscle Mass
By Anna DeLaRosby, PT, DPT, OCS, Cert. MDT
This edition covers:
- Barriers to healthy diet and exercise for GLP-1 patients
- The effects of cardiometabolic disease on the MSK system
- Designing sustainable exercise plans to improve outcomes
A commonly discussed side effect of GLP-1 medications is loss of lean muscle mass, which increases the risk of injury and may accelerate weight regain post-prescription. Knowing this, it’s imperative to engage the patient in a healthy diet and regular exercise program. However, 90% of individuals with obesity have existing musculoskeletal (MSK) concerns, as do 58% of individuals with diabetes. When these individuals begin an exercise program they may encounter barriers related to the effects of metabolic disease on the entire MSK system, not just reduced muscle mass.
To provide the right care for patients taking GLP-1s, physical therapists and care teams must be versed on the impact that obesity and diabetes have on the entire MSK system, particularly diminished tendon health, impaired muscle function and joint degradation.
Diminished Tendon Health
Chronic tendinopathy, a painful condition of the tissues that connect muscle to bone, is common in the general population, present in up to 30% of medical consultations for MSK conditions. However, the risk for tendinopathy increases dramatically in the presence of metabolic disease. Individuals with type 2 diabetes mellitus (T2DM) are four times more likely to experience tendinopathy. For those with obesity, the metabolic effects of excess weight stimulate collagen disorganization, decrease elasticity of tendons, and reduce fiber sliding, thus contributing to the development and progression of tendinopathy.
While GLP-1-induced weight loss can decrease mechanical load on the tendon, the decreased tensile strength of the tendon and risk of developing tendon injury may persist even after a healthy weight is achieved. The GLP-1 medications are indicated for use in conjunction with lifestyle modifications like increased physical activity, with many patients receiving coaching on exercise. Yet overuse is a primary causative factor in developing tendinopathy, which means that an exercise program must be designed with specific consideration given to load management.
Impaired Muscle Function and Glucose Metabolism
In a healthy body, skeletal muscle plays a role in glucose homeostasis as a primary site for glucose uptake. Additionally, muscle contractions result in secretion of myokines, which are proteins that act as messengers to other organs in our body. Myokines stimulate a host of actions in our body that improve insulin secretion, regulate mitochondrial function in cells, increase the breakdown of fat, and promote glucose oxidation to create energy throughout the body. However, the onset of obesity results in lipid accumulation within muscles, impairing glucose regulation mechanisms. Obesity also promotes persistent inflammation, which causes fibrotic tissue to infiltrate muscles and surrounding connective tissue, impairing tissue structure, decreasing the release of myokines, and reducing strength and function of muscles. These impairments lead to functional changes such as reduced gait speed, increased risk of falls, lower grip strength and overall increased risk of disability.
As the patient works toward discontinuation of the medication, the importance of a healthy musculoskeletal system for maintaining healthy glucose metabolism and the downstream effects on systemic inflammation, insulin regulation, and metabolism is paramount.
Degeneration of Joint Health
Osteoarthritis (OA), long thought to be the result of mechanical “wear and tear,” is now understood to be a multifactorial condition strongly correlated with metabolic abnormalities.
Systemic inflammation that is characteristic of obesity and diabetes can, over time, damage tissues in the body, and accelerate the degeneration of joints and development of osteoarthritis.
As arthritis is a significant cause of physical activity limitations, disability, and chronic pain, exercise prescription in this population requires an understanding of how to support, strengthen, and move potentially arthritic joints.
Exercise is a critical component to long-term health management with GLP-1 use. For individuals with a history of cardiometabolic disease, designing effective and sustainable exercise plans requires a great deal of nuance. These plans should evaluate and accommodate mobility limitations, as well as the potential for tendinopathy, impaired muscle function and arthritic changes. Further, a successful long-term exercise program is one that is designed with the flexibility to accommodate for the evolution of function and health of the patient, enabling the individual to meet the recommendations for physical activity set by the CDC (Physical Activity Guidelines for Americans, 2nd edition, 2018). While the musculoskeletal effects of obesity and diabetes are major considerations in building patient care plans, they don’t have to be a barrier to achieving a healthy, active lifestyle.
