Increasing physical fitness levels associated with reduced risk of prostate cancer

In a recent study published in the British Journal of Sports Medicine, researchers investigate the relationship between changes in adult cardiorespiratory fitness (CRF) and the incidence and mortality of prostate cancer.

Background

In contrast to other cancers, such as those affecting the breast, colon, and lungs, wherein preventable risk factors are well-established, it remains unclear which factors increase an individual’s risk of prostate cancer. The primary known risks include developmental factors and being overweight or obese, particularly for advanced prostate cancer; however, evidence is limited for non-advanced cases.

While physical activity influences various cancer types, its impact on prostate cancer remains unclear, with studies showing mixed results. CRF, which is associated with lower systemic inflammation and improved health markers, has been less explored in prostate cancer research. The conflicting findings in CRF and physical activity studies, which are potentially influenced by higher screening rates among fitter individuals, emphasize the need for additional studies.

About the study

Researchers analyzed data from the Health Profile Assessment (HPA) database managed by the Health Profile Institute in Stockholm, Sweden. The HPA offered to employees of associated companies at no cost, included lifestyle questionnaires and a submaximal ergometer CRF test.

CRF was measured using the validated Åstrand test, and participants were categorized into groups based on more than 3% changes in absolute CRF. Prostate cancer incidence and mortality data were obtained from Swedish national health registries linked to the HPA database.

Statistical analysis involved Cox proportional hazard regression models to examine the relationship between CRF changes and prostate cancer. The researchers adjusted for factors like age, body mass index (BMI), and smoking. Sensitivity analysis was conducted to mitigate reverse causality concerns.

All analyses adhered to established statistical assessment guidelines and were performed using R Studio and associated packages.

Study findings

Between 1982 and 2019, data were acquired from 181,673 men, 58,971 of whom met the criteria of having two or more CRF tests with a minimum gap of 11 months between the tests.

After excluding 1,319 individuals for extreme CRF changes, the sample consisted of 57,652 men with a mean 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, 46 of whom died from the disease.

At baseline, the absol…

A positive correlation was also observed between changes in absolute CRF and self-reported physical activity. However, changes in CRF did not correlate with prostate cancer mortality, as evidenced by the 46 observed deaths in the study.