Blood tests that measure protein levels can provide a snapshot of overall health

Circulating protein levels may serve as a biomarker for cardiorespiratory fitness, an important but previously difficult to measure component of overall health, according to A study published in Naturopathy.

Although cardiorespiratory function can provide a snapshot of holistic health, there is currently no standardized method to measure cardiorespiratory fitness, says Ravi Kalhan, MD, MS, professor of medicine in the Division of Pulmonary and Critical Care, of Preventive Medicine in the Division Epidemiology. and co-author of the study.

“As a physician who treats patients, I cannot measure the condition of a patient sitting in front of me,” says Kalhan, also the Louis A. Simpson professor of pulmonary medicine. “We could do several fancy tests, but that’s a big undertaking, and not every patient can walk on a treadmill, like those who are older or have chronic lung disease.”

Cardiorespiratory fitness affects almost every system in the body, from metabolism to the brain, Kalhan said. By developing a way to measure this, doctors could accurately assess overall health.

“This is a much more global finding that we wanted to measure through biomarkers, as opposed to single biomarkers that reflect an organ system, such as LDL cholesterol,” Kalhan said.

In the study, Kalhan and his collaborators used statistical modeling to identify circulating proteins that had the greatest impact on overall health in more than 14,000 study participants. The researchers then created a cardiorespiratory fitness score that took into account an individual’s levels of key circulating proteins, including those involved in inflammation, neuronal survival and growth, and oxidative stress, among other things.

They then validated their scoring system using data from 20,000 individuals in the UK Biobank and found that a favorable score was associated with a reduced risk of all-cause mortality, the study said.

To further test their scoring system, the researchers analyzed the circulating proteins of more than 600 people before and after a 20-week exercise program. According to the findings, the cardiorespiratory fitness score of the study participants was found to correlate with the positive effects of exercise on their cardiorespiratory system.

The findings lay the foundation for a scoring system that can accurately assess holistic health with a simple blood test, Kalhan said, and could help scientists better understand the link between fitness and health.

“We don’t really know why improving fitness improves health,” Kalhan said. “In the long term, this could help us understand the biology of what happens when someone improves their fitness, and then we can understand the mechanism and target specific biological pathways to improve health.”

Building on this development, Kalhan and his colleagues will look to apply the protein scoring methodology to other areas of overall health, he said.

“We know a lot about health trajectories. Someone may be on a declining trajectory, but when we see patients at a certain point in time, it’s very difficult for us to extrapolate what a trajectory of someone’s health might be,” Kalhan said. “If we could apply these measurements at one point in time using a blood test that reflects a larger, more difficult to determine health factor, that would be really interesting.”