Physiological Markers Redefine Treadmill Testing

In the Indonesian oil and gas industry, a predominantly male workforce undergoes rigorous health screenings to ensure their fitness for duty. One such screening, the exercise treadmill test (TMT), is a standard tool for assessing cardiovascular health in safety-sensitive workers. However, with age-based screening protocols generating a high volume of asymptomatic examinations, researchers sought to explore alternative methods for prioritizing TMTs.

A recent study analyzed occupational surveillance records from 3,631 workers, including 3,544 men and 87 women, who underwent universal TMT between 2024 and 2025. The results revealed 40 positive TMT responses, prompting investigators to search for physiological indicators that could help stratify these responses. By examining routinely collected data, they identified hemoglobin and estimated glomerular filtration rate (eGFR) as potential markers.

Higher hemoglobin levels were found to be independently associated with lower odds of a positive TMT response. In fact, for every unit increase in hemoglobin, the likelihood of a positive TMT response decreased by 27%. This finding suggests that physiological reserve markers, such as hemoglobin, may provide valuable information for exploratory stratification.

Using a reduced exploratory model that included hemoglobin and eGFR, researchers demonstrated moderate discrimination and visual calibration agreement. Notably, within the study cohort, 11.3% of workers (409 individuals) were classified as low-risk, with no observed positive TMT responses. While these findings are promising, the treadmill prioritization framework remains hypothesis-generating and requires external validation before it can be used to modify TMT intervals or reduce testing.

The study's results have significant implications for occupational health and safety. By incorporating physiological markers into the TMT prioritization process, industries may be able to optimize resource allocation and reduce the number of unnecessary tests. However, further research is needed to confirm these findings and establish the long-term benefits of this approach.