What is Decreased Muscle Mass?
Decreased muscle mass, known medically as sarcopenia, is a common condition characterized by a loss of skeletal muscle tissue, muscle strength, and muscle function that can occur with aging and certain diseases. Some key points about decreased muscle mass include:
- It involves both the loss of muscle fiber numbers and atrophy (shrinkage) of remaining muscle fibers. This leads to weaker, smaller muscles.
- Sarcopenia typically starts around age 30 and progresses more rapidly after age 60. Up to 30% of seniors are affected.
- Main causes are aging, lack of exercise, poor nutrition, and diseases like cancer or kidney failure. Genetics and hormonal changes also play a role.
- Symptoms involve feeling physically weaker, fatigue, unsteady gait, and a higher risk of falls and fractures.
- Diagnosis often involves measurements of muscle mass and strength, blood tests, MRIs or CT scans. There are no standard diagnostic cut-offs.
- Treatments focus on resistance training and ensuring adequate protein and calories. Some medications may help too.
To expand more on this important topic that impacts many older adults:
Muscle tissue naturally declines with age as part of sarcopenia. Our motor neurons shrink over time, so muscles receive fewer signals to contract. Muscle fibers also decrease in number and shrink in size, replaced by fat and connective tissue. We lose fast-twitch muscle fibers especially.
All this leads to smaller, weaker muscles with less stamina - ie, decreased muscle mass. Grip strength declines significantly, gait becomes unsteady, and even simple daily tasks can get difficult. Risk of falls and fractures skyrockets too.
Beyond natural aging, other common causes of reduced muscle mass include:
- Inactivity and disuse of muscles
- Malnutrition or inadequate protein intake
- Chronic diseases like cancer, kidney failure, or heart failure
- Inflammatory diseases like arthritis or autoimmune disorders
- Endocrine disorders like diabetes or an overactive thyroid
If you notice increasing weakness during everyday activities, it's smart to consult your physician. They can evaluate possible causes and severity through:
- Physical exams assessing strength
- Blood tests checking hormone, protein, and vitamin D levels
- CT scans or MRIs visualizing muscle size
The best treatments for low muscle mass involve:
- Resistance training to rebuild muscle size and strength
- Getting adequate dietary protein - up to 1 gram per kilogram of body weight
- Ensuring sufficient intake of calories, vitamins like B12 and minerals like zinc
- Controlling any related diseases and conditions
- Sometimes, medication if underlying causes warrant it
The takeaway - decreased muscle mass is common with aging but often accelerated by disease and poor nutrition. See your physician if experiencing troubling symptoms. Therapies aim to improve modifiable risk factors, especially inactivity and protein intake, to regain strength. Catching it early makes muscle rebuilding easier!