Leisure and occupational physical activity and risk of colorectal adenomatous polyps

Abstract

Multiple studies have shown a protective effect for physical activity on the incidence of colorectal cancer, but few have addressed its association with incident adenomas and none have investigated its association with metachronous adenomas. We interviewed 2,001 patients undergoing colonoscopy in 3 New York City practices between 1986-1988. Of these, 298 had a first diagnosis of adenomas, 506 had normal colonoscopies, I97 had metachronous adenomas and 345 had normal colonoscopies with a past history of adenomas. Subjects were queried regarding use of moderate amounts of recreational exercise (swimming, jogging, biking, racket sports and other sports) on a regular basis, and were also asked to estimate their level of physical activity. Occupational physical activity was assessed through a blinded coding of occupational titles. After adjusting for age, years of education, body mass index, total caloric intake, dietary fiber intake, dietary fat intake and years of cigarette smoking, protective effects of borderline significance were observed among males for leisure physical activity for metachronous and incident cases. Occupational physical activity was found to be significantly protective in male incident cases. Men with increased levels of either occupational or leisure activity showed a reduction for incident and metachronous cases. No effects were observed for females. Thus, in this study, both leisure and occupational physical activity were associated with a reduced risk of incident and metachronous adenomas among men but not women. These studies have investigated both leisure timc activity and occupational physical activity. The importance of physical activity as a preventive agent is enhanced by the fact that it is a modifiable lifestyle factor, thus offering the opportunity for prevention and intervention strategies. In addition, its protective effects against coronary artery disease and possibly other cancers enhance its value in future public health programs.Adenomatous SUBJECTS AND METHODSWe collected patients undergoing colonoscopy in three private practices in New York City between April, 1986-March, 1988. To be eligible, subjects were required to have had a complete colonoscopy (defined as beyond the splenic flexure; 90% of our subjects had colonoscopy to the cecum); to be English-or Spanish-speaking; to live in the tristate area (New York, New Jersey and Connecticut); to have no prior diagnosis of inflammatory bowel disease (IRD); and to be between ages 35-84 years. Of the 3,008 patients who underwent colonoscopy during this time frame, 2,443 (81.8%) were eligible for our study. Of the eligible patients, 2,001 (81.9%) were successfully interviewed. Most of the colonoscopies were conducted for symptoms such as rectal bleeding.Intervicws were conducted both by telcphonc (71%) and by mailed questionnaire (29%) with follow-up tclcphone calls to complete incomplete items, generally 2-10 weeks following colonoscopy. The questionnaire collected information on demographics, lifcstylc, past medical history a...

A Follow-up Study of Physical Activity and Incidence of Colorectal Polyps in African-American Women

“…Among the casecontrol studies (4,(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17), most were small with V300 adenoma cases (4, 7-9, 11, 13-17), and statistically significant inverse associations were found in only 2 (16,17). In a follow-up of nurses who had undergone endoscopy, during which 439 adenomas of the distal colorectum were reported, the IRR was 0.58 (95% CI 0.40-0.86) for the highest quintile of weekly energy expenditure from walking and exercise relative to the lowest (P trend = 0.0009; ref.…”

“…There is much less evidence on whether physical activity protects against colorectal adenomas, which are thought to be precursors to most colon cancers (3), and the evidence has been inconsistent (4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17). No findings have been reported on the relation of physical activity to the incidence of colorectal adenomas in African-American women.…”

Primary Prevention of Colorectal Cancer

“…Similarly, in the NHS, women who expended >21 metabolic equivalent task-hours (MET-hours)/week had a RR of colon cancer of 0.54 (CI, 0.33–0.90), compared with women who expended< 2 MET-hours/week 245. Moreover, higher levels of physical activity have been associated with a reduced risk of colon adenoma and particularly large or advanced lesions 242, 245, 276, 277. Although a physically active lifestyle might be associated with other healthful behaviors, a number of characteristics of the findings indicate that higher levels of physical activity level directly prevent lower colon cancer.…”

An Update of Cancer Incidence in the Agricultural Health Study

“…(3) The lower incidence of colorectal cancer may be influenced by the high rates of physical activity associated with farm activities. (4;5) On the other hand, lymphohematopoietic cancers, prostate cancer, melanoma, and brain tumors have been reported to be in excess among agricultural workers. (6–10) Similarly, excess mortality has been reported for these same cancer sites in agricultural populations (2) which could to be linked to exposures such as pesticides, viruses, bacteria, fungi, sunlight, dusts, and other chemicals.…”