A recently published study in the British Journal of Sports Medicine examines the association between changes in cardiorespiratory fitness (CRF) in adults and the incidence and mortality of prostate cancer.
Study: Association between changes in cardiorespiratory fitness and the incidence and mortality of prostate cancer in 57,652 Swedish men. Image source: Peakstock / Shutterstock.com
Unlike other cancers such as breast, colon, and lung cancer, where avoidable risk factors are well known, it remains unclear which factors increase a person’s risk of prostate cancer. While known risk factors include developmental factors, overweight or obesity, particularly in advanced prostate cancer, the evidence for non-advanced cases is limited.
While physical activity influences various types of cancer, its impact on prostate cancer is unclear, with studies showing mixed results. Cardiorespiratory fitness (CRF), associated with lower systemic inflammation and improved health markers, has been less studied in prostate cancer research. The contradictory results in CRF and physical activity studies, potentially influenced by higher screening rates in fitter individuals, highlight the need for additional research.
About the Study
Researchers analyzed data from the Health Profile Assessment (HPA) database managed by the Health Profile Institute in Stockholm, Sweden. The HPA was offered free of charge to employees of affiliated companies and included lifestyle questionnaires and a submaximal ergometer CRF test.
CRF was measured using the validated Åstrand test, and participants were categorized based on more than 3% changes in absolute CRF. Data on prostate cancer incidence and mortality were obtained from Swedish national health registries linked to the HPA database.
Statistical analysis included Cox proportional hazard regression models to investigate the association between CRF changes and prostate cancer. Researchers adjusted for factors such as age, body mass index (BMI), and smoking. A sensitivity analysis was conducted to address concerns about reverse causality.
All analyses followed established statistical assessment guidelines and were conducted using R Studio and associated packages.
Between 1982 and 2019, data from 181,673 men were recorded, of which 58,971 met the criteria to undergo two or more CRF tests with a minimum spacing of 11 months between the tests.
After excluding 1,319 individuals due to extreme CNI changes, the sample consisted of 57,652 men with an average age of 41.4 years and an average BMI of 26.0 kg/m2. Among these individuals, 592, or 1% of the study cohort, were diagnosed with prostate cancer, of which 46 died from the disease.
At the start of the study, the absolute and average relative CRF values were 3.12 l/min and 37.4 ml/kg/min, respectively. Over an average period of 4.9 years between the tests, there was a slight decline in both relative and absolute CRF. The follow-up period for the incidence analysis averaged 6.7 years from the last CRF test.
After adjusting for factors such as age, BMI, and smoking status, no association was observed between CRF at the beginning or the last test and the risk of prostate cancer. However, unadjusted analyses showed a reverse association between higher CRF at both time points and prostate cancer risk.
- Bolam, KA, Bojsen-Møller, E., Wallin, P., et al. (2024). Association between changes in cardiorespiratory fitness and the incidence and mortality of prostate cancer in 57,652 Swedish men. British Journal of Sports Medicine. doi:10.1136/bjsports-2023-107007