CohortHumann = 3002024
Chemokine CXCL9, a marker of inflammaging, is associated with changes of muscle strength and mortality in older men.
Plain-language summary
This study looked at whether higher levels of CXCL9 (a protein linked to age-related inflammation) were tied to worse muscle function and higher death risk in older men. It tracked 300 men around age 79 from the MrOS study, measuring their walking speed, chair-stand ability, hip bone density, fractures, and death rates over time. Higher CXCL9 levels were linked to slower chair stands and nearly double the death risk in the top quarter compared to the bottom, but not to fractures or bone-density changes.
Key findings
- Higher CXCL9 levels were linked to slower chair stands (a test of leg strength and mobility) in older men.
- Men in the top 25% for CXCL9 had nearly double the death risk compared to those in the bottom 25%.
- CXCL9 was not tied to changes in walking speed, hip bone density, or fracture risk.
How to analyze the study yourself
- Study type
- Cohort studies track groups over time to spot links between factors like CXCL9 and health outcomes, but cannot prove one causes the other.
- Population
- Older men (average age 79) from the MrOS study, a group already being tracked for bone and muscle health.
- Funding
- Not reported
- Takeaway
- This study found that older men with the most CXCL9 in their blood, a signalling protein that rises with age-related inflammation where lower is better, were slower over six meters, slower out of a chair, and about twice as likely to die over the follow-up than men with the least. Once the researchers adjusted for everything else, only the chair-stand decline still tracked with it. CXCL9 is not a test you can ask for and nothing here shows that lowering it helps. What it does show is that low-grade inflammation and losing leg strength travel together, and resistance training is what improves leg strength.