Reduced Risk of Incident Kidney Cancer from Walking and Running

Abstract

Purpose: 
This study aimed to test whether incident kidney cancer risk is associated with exercise energy expenditure (i.e., metabolic equivalents, 1 MET) when calculated from distance walked or run.
Methods
Hazard ratios (HR) and 95% confidence intervals (95% CI) from Cox proportional hazard analyses of self-reported physician-diagnosed incident kidney cancer versus MET-hours per week in 91,820 subjects recruited between 1991 and 1993 (7.7 yr follow-up of 42,833 subjects) and between 1998 and 1999 (6.4 yr follow-up of 33,053 subjects) as part of the National Runners´ Health Study and between 1998 and 1999 as part of the National Walkers´ Health Study (5.7 yr follow-up of 15,934 subjects).
Fifty-two incident cancers were reported. Age- and sex-adjusted risk declined 1.9% per MET-hour per week run or walked (HR = 0.981, 95% CI = 0.964-0.997, P = 0.02). Compared with walking or running below guidelines levels (<7.5 MET·h·wk-1), the risk for incident kidney cancer was 61% lower for meeting the guidelines (HR = 0.39, 95% CI = 0.11-1.08, P = 0.07 for 7.5-12.5 MET·h·wk-1), 67% lower for exercising one to two times the recommended level (HR = 0.33; 95% CI = 0.15-0.72, P = 0.005 for 12.6-25.1 MET·h·wk-1), and 76.3% lower for exercising two times or more the recommended level (HR = 0.24, 95% CI = 0.11-0.52, P = 0.0005 for ≥25.2 MET·h·wk-1). Incident kidney cancer risk also increased in association with baseline body mass index (P = 0.002), smoking (P = 0.02), and hypertensive (P = 0.007) and diabetes medication use (P = 0.01); however, exercise-associated reductions in kidney cancer risk persisted for 12.6-25.1 MET·h·wk-1 (HR = 0.35,P = 0.01) and ≥25.2 MET·h·wk-1 (HR = 0.29, P = 0.004) vis-à-vis <7.5 MET·h·wk-1 when also adjusted for body mass index, hypertension, diabetes, and pack-years smoked.
Conclusion: 
Running and walking may reduce incident kidney cancer risk independent of its other known risk factors. 

Autor / Fonte:WILLIAMS, PAUL T. Medicine & Science in Sports & Exercise: February 2014 - Volume 46 - Issue 2 - p 312–317 doi: 10.1249/MSS.0b013e3182a4e89c
Link: http://journals.lww.com/acsm-msse/Fulltext/2014/02000/Reduced_Risk_of_Incident_Kidney_Cancer_from.13.aspx