This Blood Marker Was Linked To 36% Lower Sarcopenia Risk
We tend to notice muscle loss when it starts getting in the way, like when lifting something that used to feel easy suddenly takes more effort.
But researchers are interested in catching those changes much earlier. Could a simple blood test help identify who's more likely to lose muscle as they age?
A new study explored this question by looking at a protein called Tsukushi (TSK), investigating whether its levels in the blood could help predict sarcopenia, the gradual loss of muscle mass and strength that comes with aging.
About the study
TSK is a protein made mainly by the liver that travels through the bloodstream. Previous research in mice suggests it helps maintain muscle mass, strength, and endurance.
Mice lacking TSK showed weaker grip strength and poorer exercise performance, but its relationship with human muscle health is less understood.
To investigate, researchers followed 1,370 adults ages 65 and older in Jiangsu Province, China, over four years.
They measured participants' blood TSK levels at the beginning of the study, then assessed their muscle mass, grip strength, and walking speed over the four-year follow-up.
Participants were also divided into three groups based on their initial TSK levels, from lowest to highest.
Higher TSK levels were linked to 36% lower sarcopenia risk
The researchers found a clear pattern: participants with the lowest TSK levels were more likely to develop sarcopenia over the four years. They also had higher rates of low muscle mass, weak grip strength, and slow walking speed.
After accounting for factors such as sex, BMI, high blood pressure, and diabetes, each incremental increase in TSK was associated with a 36% lower risk of developing sarcopenia.
This association remained even after researchers accounted for participants' muscle health at the start of the study.
TSK also showed potential as an early predictor. On its own, it identified future sarcopenia cases with about 70% accuracy. When combined with other health information, including BMI and cholesterol markers, predictive accuracy increased to around 81%.
The association appeared stronger in women than men.
However, the researchers say this finding needs further investigation before drawing conclusions about differences between the sexes.
What this could mean for catching muscle loss earlier
Sarcopenia is typically identified by measuring muscle mass, strength, and physical performance, meaning some decline has already occurred by the time someone receives a diagnosis.
TSK could eventually help identify people at higher risk sooner, giving them more time to protect their muscle health. However, this was a single-center study involving older adults in one region of China, so the findings need to be confirmed in other populations.
It's also important to remember that an association doesn't prove TSK directly protects muscle. The protein may reflect other aspects of overall health. For now, it isn't a routine blood test you can request to assess your muscle-loss risk.
Two ways to protect your muscles as you age
You don't need a new blood test to start supporting muscle health. Two habits remain particularly important:
- Prioritize resistance training: Use weights, resistance bands, or bodyweight exercises to challenge major muscle groups. Regular resistance training helps maintain muscle mass, strength, and physical function.
- Get enough protein: Your muscles need protein to repair and rebuild. Include a quality protein source at each meal rather than saving most of your intake for dinner. Spreading protein throughout the day helps support muscle maintenance as you age.
The takeaway
TSK could eventually give doctors another way to spot sarcopenia risk before it affects everyday life. Until then, keep lifting, keep eating enough protein, and give your muscles plenty of reasons to stick around.