Diabetologie und Stoffwechsel 2016; 11 - P190
DOI: 10.1055/s-0036-1580937

Physical activity and risk of colon cancer among diabetic and non-diabetic individuals

D Schmid 1, G Behrens 1, CE Matthews 2, MF Leitzmann 1
  • 1Department of Epidemiology and Preventive Medicine, Regensburg, Germany
  • 2National Cancer Institute, Division of Cancer Epidemiology and Genetics, Metabolic Epidemiology Branch, Bethesda, United States

Background: Increased physical activity reduces risk of colon cancer. However, whether physical activity protects against colon cancer among individuals with diabetes mellitus has not been evaluated.

Methods: We explored the relations of moderate and vigorous physical activity to colon cancer incidence in 29,199 adults with a history of diabetes and 275,051 non-diabetics of the NIH-AARP Diet and Health Study aged 50 – 71 years at baseline, followed from 1996 to 2011.

Results: During 13.0 (SD = 3.96) years of follow-up, colon cancer occurred in 481 diabetics and 4,151 non-diabetics. Compared to individuals who never/rarely exercised, diabetics participating in > 7 hours/week of physical activity showed reduced risk of colon cancer (age- and sex-adjusted hazard ratio (HR)= 0.74, 95% confidence interval (CI)= 0.55 – 0.99, Ptrend= 0.15), but the association was attenuated and no longer statistically significant after additional control for other covariates (HR = 0.77, 95% CI = 0.58 – 1.04, Ptrend= 0.27). By comparison, an inverse relation of physical activity to colon cancer was evident in non-diabetic individuals (multivariable-adjusted HR = 0.80, 95% CI = 0.73 – 0.89, P trend < 0.001).

Conclusions: In this first investigation of the physical activity and colon cancer relation among diabetics, physical activity was only suggestively associated with reduced risk of colon cancer among diabetics, whereas a statistically significant reduced risk was found among non-diabetic individuals. Future studies with a larger number of participants are required to explore whether physical activity beneficially affects colon cancer risk among diabetics.