Thread by @PrimaryCarePAC

Sarcopenia is coming to steal your health. It will sneak up on you and take your strength, mobility and independence. If you are over 30 it may already be affecting you and certainly of you are 50 or over. It is coming and you can't stop it. However, you can slow it down.

Sarcopenia is the muscle mass loss (myopenia) & strength loss (dynapenia) that is age related & not due to any disease. It may begin as early as your 30s but certainly by your 50s. By the time you are 50 you will lose about 1% of your muscle & around 1-3% of strength per year.

Sarcopenia is a true health problem. It directly leads to poor mobility, frailty, disability, and loss of independence. It also influences development or worsening of metabolic syndrome, type 2 diabetes, weight gain, cognitive decline, risk of falling, and premature death.

Sarcopenic decline can be punctuated by illness or injury. A return to baseline may not be possible.

This “normal” decline is a result of many factors including satellite cell dysfunction, mitochondrial dysfunction, anabolic resistance, decreased protein synthesis, decreased anabolic hormones, impaired vascular response, impaired regenerative capacity, & more.

The decline may be punctuated/worsened by insufficient energy, protein malnutrition, illness, hospitalization, physical activity decline, insulin resistance, increased inflammation, and more.

We need to spend more time discussing these further. It is good to know that exercise, specifically resistance training improves most of these.

In fact, if you continue to perform resistance training (i.e. lifting weights) you can have more strength at 70 years-old than someone in their 30s who doesn’t.

If you haven’t been performing resistance training, it’s not too late. Exercise programs in those over 60 years-old showed an increase in muscle by 10-30% and strength up to 100%!

Current evidence is strong that sarcopenia can be improved by physical activity and nutrition.

Older adults benefit from exercise in many ways.
⬆️ QOL
⬆️ psychological well-being
Better mental health and social integration
⬇️ risk of developing many chronic diseases
⬇️ risk of falling
⬆️likelihood of living past 80 years-old
Half the risk of dying with a disability

Walking is the most common type of exercise performed and is very important for overall health; however, in the treatment of sarcopenia, it offers little benefit. Walking provides very little loading of muscle therefore there is little strength to be gained.

However, there are many benefits to aerobic exercise including:
⬇️ inflammation
⬇️ risk of cardiometabolic disease
⬆️ muscle mitochondrial content and vascular inaction
Small ⬆️ in muscle fiber size in older adults without ⬆️ force generated
⬆️ sensitivity of muscle to protein

Resistance exercise prevents sarcopenia by:
Increased muscle mass/surface area
Improved muscle function (force and power)
Improved balance
Improved flexibility

Nutrition is of utmost importance in the treatment of sarcopenia. Sufficient protein intake is key. Eating protein stimulates muscle protein synthesis (MPS) and at the same time suppresses muscle protein breakdown (MPB). Aim for a positive protein balance in sarcopenia.

As we age we experience a reduced or blunted anabolic response to protein ingestion. This means that an increased amount of protein is required in order to give the same MPS that a lower amount would provide in someone younger.

Although there is a limit to the MPS stimulus by an amount of protein, consuming protein > this amount may serve to suppress MPB. The current US RDA for protein is 0.8 g/kg/day. However, this is not considered to be enough to maintain a positive protein balance preventing MBP.

Research suggests that a more optimal goal would be 1.1-1.2 g PRO/kg BW/day. Better would be to split this into a per-meal goal of around 0.40 g/kg BW per meal in older adults. This comes to around 30-40 g/meal for most older adults.

Following the US RDA for protein has been shown to reduce lean body mass but a per-meal protein goal can increase muscle mass.

I’ve tried to include tags or reference to studies that I have read. I apologize for those that I have inadvertently left out.

I’ve been working on this for a Facebook post but when I read a post from @DrStrength4Life w @FitGreyStrong @MegLowryPT and @DrRaulCordoba I finished it for Twitter. Certainly there is more to add and corrections are welcome!

@threadreaderapp unroll