Ample data support that leisure time aerobic moderate to vigorous physical activity (MVPA) is associated with lower risk of at least seven types of cancer. However, the link between muscle-strengthening activities and cancer etiology is not well-understood. Our objective was to determine the association of weight lifting with incidence of 10 common cancer types.
We used multivariable Cox regression to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for association of weight lifting with incidence of 10 cancer types in the NIH-AARP Diet and Health Study follow-up. Weight lifting was modeled continuously and categorically. Dose-response relationships were evaluated using cubic restricted spline models. We explored whether associations varied by subgroups defined by sex, age, and body mass index (BMI) using the Wald test for homogeneity. We examined joint categories of MVPA and weight lifting in relation to cancer risk for significant associations.
After adjusting for all covariates including MVPA, we observed a statistically significant lower risk of colon cancer (Ptrend=0.003) in individuals who weight lifted; the HR and 95% CI associated with low and high weight lifting as compared with no weight lifting were 0.75(CI:0.66,0.87) and 0.78(CI:0.61,0.98) respectively. This relationship differed between men and women (HRmen=0.91 ;CI:0.84, 0.98; HRwomen=1.00; CI:0.93, 1.08) (Pinteraction=0.008). A lower risk of kidney cancer among weight lifters was observed but became non-significant after adjusting for MVPA (Ptrend=0.06); resulting in a HR of 0.94 (CI:0.78,1.12) for low weight lifting and 0.80 (CI:0.59,1.11) for high weight lifting.
Participants who engaged in weight lifting had a significantly lower risk of colon cancer and a trend towards a lower risk of kidney cancer than participants who did not weight lift. Keywords
Resistance, strengthening, epidemiology, physical activity, colon
1Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, MD;
2Cancer Prevention Fellowship Program, Division of Cancer Prevention, National Cancer Institute, Bethesda, MD
Corresponding Author: Steven C. Moore, Metabolic Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, 9609 Medical Center Drive, Rockville, MD 20850, Telephone: 240.276.7196, e-mail: firstname.lastname@example.org
This work was supported by the Intramural Research Program of the National Cancer Institute, National Institutes of Health, Department of Health and Human Services. The authors declare no conflicts of interests. The results of the present study do not constitute endorsement by ACSM, and these results are presented clearly, honestly and without fabrication, falsification, or inappropriate data manipulation.
Accepted for publication March 2019.