Estimated cardiorespiratory fitness in relation to overall, breast and prostate cancer incidence: the Norwegian HUNT study

Abstract

Purpose: To investigate the relationships between the estimated cardiorespiratory fitness (eCRF) and the incidence of overall, breast, and prostate cancer in a large prospective cohort study.

Methods: We included 46,968 cancer-free adults who participated in the second survey of the Trøndelag Health Study in Norway. Sex-specific non-exercise algorithms were used to estimate CRF. eCRF was classified into sex and age-specific tertiles, that is, into low, medium and high levels. Cox proportional hazards models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs).

Results: Over a median of 22.1 years' follow-up, there were 7752 overall, 858 breast and 1376 prostate cancer cases. Medium and high levels of eCRF were associated with a reduced incidence of overall cancer in a dose-response manner in all participants (HR 0.96; 95% CI, 0.90-1.01 and HR 0.85; 95% CI, 0.79-0.91, respectively, and P-value for trend <.001). No association was observed between eCRF and breast cancer incidence in women. Only the high level of eCRF seemed to be associated with a reduced incidence of prostate cancer in men (HR 0.85; 95% CI, 0.72-1.02).

Conclusions: eCRF may be a practical and cost-effective means of investigating the association between the CRF and cancer incidence.

Keywords: Breast cancer; Cancer; Estimated cardiorespiratory fitness; Physical activity; Prospective cohort; Prostate cancer.