Sarcopenia – Age-Related Muscle Loss

Introduction

As the world’s population continues to grow as well as significantly age, we face unique health challenges in the elderly population. One of the most prevalent and significant issues with aging is sarcopenia. Sarcopenia is the loss of muscle mass and function with age. It affects the overall health and quality of life by affecting ambulation, mobility, energy consumption, independence and breathing. The consequences are disability and frailty.

Understanding Sarcopenia

Sarcopenia is more than just the natural consequence of aging. It is a complex syndrome influenced by various factors, including hormonal changes, nutritional deficits, physical inactivity, chronic diseases, and genetic predisposition. While it predominantly affects older adults, it can also manifest in younger individuals with certain health conditions or sedentary lifestyles.

The Impact of Sarcopenia

Functional Consequences

Sarcopenia leads to decreased muscle strength, which, in turn, affects one’s ability to perform daily activities. This can result in loss of independence and reduced quality of life for affected individuals.

Increased Fall Risk

Weakened muscles and impaired balance contribute to an increased risk of falls and fractures among sarcopenic individuals, leading to hospitalizations and, in severe cases, long-term disability.

Metabolic Ramifications

Sarcopenia is associated with metabolic disturbances, including insulin resistance and impaired glucose metabolism, contributing to the development of type-2 diabetes and obesity.

After 50 years of age, muscle mass decreases by 1 to 2% annually which further gets accelerated after 60 years of age. Various factors influence muscle loss. These include:

Sedentary Lifestyle

Physical inactivity is a major contributor for sarcopenia at any age. Being physically active reduces the risk of age-related loss of muscle mass and function.

Hormonal Changes

Ageing causes significant changes in the hormone levels. In men, the reduced testosterone levels play an important role in muscle loss since it is an important hormone which helps in protein synthesis and muscle strength. Insulin is another important factor for muscle growth. With ageing, there is fat deposition in the body which leads to insulin resistance causing muscle loss. In women, oestrogen deficiency plays a major role in sarcopenia. Similarly, low vitamin D levels are associated with muscle loss, decreased balance, and increased risk of falls.

Chronic Medical Conditions

These include heart failure and cancers which are very common among the elderly. These conditions cause chronic inflammations and the mediators of inflammation play a role in catabolism thereby leading to muscle loss.

Genetic Factors

Many genes are associated with muscle strength and changes in these genes make these individuals more susceptible to an early and severe loss of muscle strength.

Low Protein Intake

Since protein synthesis itself is reduced in the elderly, their protein intake should be higher to maintain muscle mass.

Screening:

The best screening tool to assess muscle strength in the elderly is to test gait speed. If the gait speed is less than 1 metre per second, then further evaluation should be done to check lean body mass and body composition by DEXA or bioimpedance analysis. MRI is useful in research settings. Further physical performance is assessed by doing simple tests to assess the severity of sarcopenia.

Preventing and Managing Sarcopenia

Exercise

The best and proven method to prevent as well as to treat sarcopenia is resistance training. Studies show that weightlifting increases muscle mass and strength even in frail old patients. The recommended duration is two to three non-consecutive days a week. The gained muscle mass can be maintained even by doing it once a week. Aerobic exercises do not cause muscle gain, but they help in reducing body fat and improve muscle performance. Combined activities reduce fatigue, help pain release, reduce cardiovascular risk factors, and improve balance and appetite.

Nutrition

The protein requirement of older people is higher than an average adult to regain and maintain the lost muscle mass which is 1 to 1.2 g per kg body weight except in special situations like chronic kidney diseases. In physically active elderly, the requirement for protein is much higher. Specifically, essential amino acids like leucine are essential for muscle building which are present in high concentrations in whey protein.

Hormone Replacement Therapy

In some cases, hormone replacement therapy, under medical supervision, may help counteract hormonal imbalances contributing to sarcopenia.

Pharmacological Interventions

Emerging pharmaceutical treatments, such as myostatin inhibitors and selective androgen receptor modulators (SARMs), hold promise for addressing sarcopenia, although more research is needed to ensure their safety and efficacy.

Conclusion:

Sarcopenia is a multifaceted condition that significantly impacts the health and well-being of aging individuals. Understanding its mechanisms and recognizing the importance of early prevention and management strategies is crucial in addressing this growing public health concern.

Improved understanding and treatment of sarcopenia will dramatically improve the health and quality of life of older adults thereby reducing disability, dependency, and health care costs.