Sarcopenia (Age-Related Muscle Loss) & Sarcopenic Obesity

Sarcopenia (Muscle Loss) Treatment and Management of Sarcopenic Obesity

"Are my muscles disappearing as I get older — and can this be prevented?"

"My weight is normal, but my muscles feel very weak. What does that mean?"

"I'm having difficulty getting up from a chair, and climbing stairs has become much harder."

"I'm overweight, but I've been told I'm also losing muscle. Is that possible?"

Sarcopenia is the progressive loss of skeletal muscle mass, strength, and physical function associated with aging. It is no longer considered simply a sign of "old age weakness." Since 2016, sarcopenia has been recognized as a disease with its own ICD-10-CM diagnosis code (M62.84) and is regarded as a clinical condition that requires appropriate diagnosis and treatment (Anker et al., Journal of Cachexia, Sarcopenia and Muscle, 2016).

Worldwide, sarcopenia affects approximately 10–16% of adults over the age of 60 (Cruz-Jentoft et al., Age and Ageing, 2019). In Türkiye, the reported prevalence among adults aged 65 years and older ranges from 15% to 25%.

Which of These Concerns Applies to You?

-What is sarcopenia, and what causes it?

-How can I tell if I have sarcopenia? Diagnostic criteria

-What is sarcopenic obesity?

-Sarcopenia treatment: Exercise and nutrition

-Does sarcopenia increase the risk of falls and fractures?

What Is Sarcopenia? What Causes It?

The Physiology of Muscle Loss

After the age of 30, skeletal muscle mass decreases by approximately 3–8% per decade. After the age of 60, this decline accelerates and may reach 1–2% per year (Doherty, Journal of Applied Physiology, 2003).

Several biological mechanisms contribute to this process:

-Loss of motor neurons: With aging, motor neurons that innervate fast-twitch (Type II) muscle fibers are preferentially lost.

-Decline in anabolic hormones: Reduced levels of testosterone, IGF-1, and growth hormone decrease muscle protein synthesis.

-Chronic inflammation (inflammaging): Pro-inflammatory cytokines such as IL-6 and TNF-α accelerate muscle breakdown.

-Reduced protein synthesis: The muscle protein synthesis response after meals (postprandial response) becomes less effective with age, making both the amount and timing of protein intake increasingly important.

-Physical inactivity: A sedentary lifestyle is one of the most significant and modifiable factors contributing to muscle atrophy.

Why Is Sarcopenia Important?

Sarcopenia is much more than simply having weak muscles. Systematic reviews have shown that the presence of sarcopenia is associated with significantly increased health risks, including:

-A threefold increase in the risk of falls (Morley et al., Journal of the American Medical Directors Association, 2014)

-A 2.3-fold increase in fracture risk

-An increased risk of hospitalization

-A higher risk of cardiometabolic diseases

-A 2.5-fold increase in all-cause mortality

How Is Sarcopenia Diagnosed?

EWGSOP2 Diagnostic Criteria (2019)

According to the 2019 update of the European Working Group on Sarcopenia in Older People (EWGSOP2) (Cruz-Jentoft et al., Age and Ageing, 2019), the diagnosis is made in three steps:

Step 1 – Screening

-SARC-F questionnaire (5 questions, scored from 0–10)

-A score of 4 or higher suggests a high risk of sarcopenia.

Step 2 – Diagnosis

-Handgrip strength measured with a dynamometer or

-Chair Stand Test

Reduced performance on either test indicates probable sarcopenia.

Step 3 – Severity Assessment

-Sarcopenia: Low muscle strength plus low muscle mass (measured by DEXA or BIA).

-Severe sarcopenia: Low muscle strength, low muscle mass, and poor physical performance (walking speed <0.8 m/s or SPPB score ≤8).

Practical Assessment Methods

-Handgrip Strength: Measured using a dynamometer. Cut-off values are <27 kg for men and <16 kg for women (EWGSOP2).

-Five-Time Chair Stand Test: Taking more than 15 seconds is considered abnormal.

-Gait Speed: A walking speed of less than 0.8 m/s indicates reduced physical performance.

-Muscle Mass Assessment (DEXA): Appendicular Skeletal Muscle Mass Index (ASMI) values of <7.0 kg/m² in men and <5.5 kg/m² in women are considered low.

Sarcopenic Obesity: "Normal Weight, Low Muscle"

A Hidden Clinical Condition

Sarcopenic obesity is the coexistence of low muscle mass and excess body fat. Although body weight may appear normal, muscle mass is insufficient because fat tissue has gradually replaced muscle.

This condition is particularly common among individuals described as "skinny fat." A person may appear to have a healthy weight on the scale, yet body composition analysis using DEXA or bioelectrical impedance analysis (BIA) may reveal significantly reduced muscle mass.

The prevalence of sarcopenic obesity is estimated to be 5–10% among adults over the age of 60 (Baumgartner et al., Obesity Research, 2004).

Compared with sarcopenia or obesity alone, sarcopenic obesity carries a substantially higher risk of metabolic disorders, cardiovascular disease, and functional decline.

What Causes Sarcopenic Obesity?

Several factors contribute to the development of sarcopenic obesity:

-Sedentary lifestyle combined with excessive calorie intake: Body fat increases while insufficient physical activity fails to preserve muscle mass.

-Chronic inflammation: Visceral fat releases pro-inflammatory cytokines that accelerate muscle breakdown.

-Insulin resistance: Reduces muscle protein synthesis and contributes to muscle loss.

-Rapid weight loss: A significant portion of weight lost during dieting may come from muscle tissue. Dieting without resistance exercise can therefore accelerate sarcopenia.

Treatment Approach

The goal of treating sarcopenic obesity is not simply weight loss. Instead, the primary objective is to increase muscle mass while reducing excess body fat.

The most effective strategy combines:

-Resistance exercise

-Adequate daily protein intake

-A moderate calorie deficit

Together, these interventions help preserve and build muscle while promoting healthy fat loss.

Sarcopenia Treatment: Exercise and Nutrition

1. Resistance Training – The Most Effective Intervention

Resistance training is the most evidence-based treatment for sarcopenia.

Even in older adults, muscle hypertrophy is achievable, making the common belief that "muscle cannot be built in old age" a misconception.

Meta-analyses have demonstrated that resistance training can increase muscle mass by approximately 1.1 kg and improve muscle strength by 25–30% in individuals with sarcopenia (Peterson et al., American Journal of Medicine, 2011).

Recommended Exercise Protocol

Important: Resistance training should always begin with low resistance, as tendons and joints may be more vulnerable to injury, particularly in older adults.

Recommended guidelines include:

-Perform resistance training 2–3 times per week.

-Complete 8–12 repetitions per set at 60–80% of one-repetition maximum (1RM).

-Prioritize major muscle groups, including squats, leg press, back, and chest exercises.

-Gradually increase the training load over time (progressive overload).

2. Protein Intake

Older adults require more protein than the general recommended daily intake of 0.8 g/kg/day.

According to the European Society for Clinical Nutrition and Metabolism (ESPEN), older adults with sarcopenia or chronic diseases should consume 1.2–1.5 g of protein per kilogram of body weight per day (Bauer et al., Journal of the American Medical Directors Association, 2013).

Key recommendations include:

• Protein quality matters: Protein sources rich in leucine, such as dairy products, eggs, and lean meat, are the most effective at stimulating muscle protein synthesis.
• Whey protein: Due to its rapid absorption, whey protein is considered an ideal post-workout protein source to support muscle recovery and growth.
• Protein timing: Consuming protein within 30–60 minutes after exercise helps maximize the anabolic response and muscle protein synthesis.

3. Vitamin D

Vitamin D deficiency is independently associated with reduced muscle strength and impaired physical performance.

Vitamin D directly influences muscle protein synthesis through receptors located within muscle cell nuclei (Bischoff-Ferrari et al., American Journal of Clinical Nutrition, 2004).

Serum 25-hydroxyvitamin D [25(OH)D] levels should ideally be maintained at ≥50 nmol/L. Supplementation is recommended when deficiency is identified.

4. Creatine Supplementation

When combined with resistance training, creatine monohydrate provides additional improvements in muscle strength and physical function in older adults (Gualano et al., Medicine & Science in Sports & Exercise, 2014).

A daily dosage of 3–5 grams has been shown to be both safe and effective.

5. Physical Medicine and Rehabilitation (PM&R)

A comprehensive rehabilitation program may include:

-Individual assessment and a personalized exercise prescription.

-Balance and gait training.

-Functional movement exercises, such as chair-rise practice and stair climbing.

-Integration of fall prevention programs to improve safety and independence.

Sarcopenia, Osteoporosis, and Fractures: A Triple Threat

Sarcopenia and osteoporosis are closely interconnected conditions that often reinforce one another.

Loss of muscle mass reduces the mechanical load placed on bones, accelerating bone loss. At the same time, decreased muscle strength increases the risk of falls, thereby raising the likelihood of fractures. This combination is known as osteosarcopenia (Huo et al., Journal of Cachexia, Sarcopenia and Muscle, 2015).

An even more severe condition, osteosarcopenic obesity, occurs when osteoporosis, sarcopenia, and obesity coexist. This increasingly recognized syndrome is associated with the highest risk of cardiometabolic disease, disability, and all-cause mortality.

For this reason, DEXA scanning should be used not only to evaluate bone mineral density, but also to assess body composition, including muscle mass and fat mass, allowing for a comprehensive evaluation and individualized treatment planning.