Increasing fitness levels are associated with lower prostate cancer risk

In a recent study published in British Journal of Sports Medicine, Researchers are investigating the relationship between changes in cardiorespiratory fitness (CRF) and prostate cancer incidence and mortality in adults.

study: Association between changes in cardiorespiratory fitness and prostate cancer incidence and mortality in 57,652 Swedish men. Image credit: Peakstock / Shutterstock.com

background

In contrast to other cancers such as breast, colon, and lung cancer, where preventable risk factors are well established, it remains unclear which factors increase an individual’s risk for prostate cancer. The main known risks include developmental factors, especially in the case of advanced prostate cancer, being overweight or obese. However, evidence for cases that are not progressing is limited.

Although physical activity affects many types of cancer, its effect on prostate cancer remains unclear, and studies have shown mixed results. CRF is associated with reduced systemic inflammation and improved health markers, but has been less studied in prostate cancer research. Studies of CRF and physical activity have yielded conflicting results, which may be influenced by high screening rates in healthy individuals, highlighting the need for additional research.

About research

The researchers analyzed data from the Health Profile Assessment (HPA) database maintained by the Health Profile Institute in Stockholm, Sweden. His HPA, which was provided free of charge to associate company employees, included a lifestyle questionnaire and a submaximal ergometer CRF test.

CRF was measured using the validated Åstrond test, and participants were classified into groups based on a ≥3% change in absolute CRF. Prostate cancer incidence and mortality data were obtained from the Swedish National Health Register linked to the HPA database.

Statistical analyzes included Cox proportional hazards regression models to examine the relationship between CRF changes and prostate cancer. Researchers adjusted for factors such as age, body mass index (BMI), and smoking. Sensitivity analyzes were conducted to alleviate concerns of reverse causation.

All analyzes adhered to established statistical evaluation guidelines and were performed using R Studio and associated packages.

research result

Between 1982 and 2019, data were collected from 181,673 men, of whom 58,971 had two or more CRF tests and met the criteria of a minimum 11-month interval between tests. .

After excluding 1,319 individuals with extreme changes in CRF, the sample consisted of 57,652 men with a mean age of 41.4 years and a mean BMI of 26.0 kg/m2.². Of these people, 592, or 1% of those in the study, were diagnosed with prostate cancer, and 46 of them died from prostate cancer.

At baseline, the absolute and mean relative CRF values ​​were 3.12 L/min and 37.4 mL/kg/min, respectively. There was a slight decline in both relative and absolute CRF with an average of 4.9 years between tests. Follow-up for incidence analysis averaged 6.7 years from the last CRF test.

No association was observed between baseline or last test CRF and prostate cancer risk, even after adjusting for factors such as age, BMI, and smoking status. However, in unadjusted analyses, high CRF was inversely associated with prostate cancer risk at both time points.

Notably, decreased absolute CRF was correlated with increased risk of prostate cancer diagnosis. This association remained significant after adjusting for all covariates, including physical activity.

Participants were also categorized by change in CRF, which included +3%, ±3%, -3% increase, stable, or decrease, respectively. The group with increased CRF had a significantly lower risk of developing cancer compared with the stable group, and this was consistent across most adjusted models.

Sensitivity analyzes excluding early diagnoses after the last test confirmed the importance of absolute change in CRF on cancer risk. However, when comparing stable CRF with increased or decreased groups, large variations were observed between different models.

Subgroup analyzes stratified by baseline CRF levels showed that in the moderate baseline CRF group of 32.4 to 40.7 mL/kg/min, each standard deviation increase in absolute CRF resulted in prostate cancer in the least adjusted model. It was found that the risk of developing cancer was reduced by 16%. , the significant association persists in the more adjusted model. Comparatively, low and high fitness groups showed no significant association, except for an inverse association for the high fitness group in the least adjusted model, which decreased upon further adjustment.

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