Biomedical subjects

Lisa H Colbert

Publications and source records attributed to Lisa H Colbert.

21 records · Page 2Linked to original sources

PubMed2002

Physical activity and lung cancer risk in male smokers.

We examined the association between physical activity and lung cancer in a prospective cohort of 27,087 male smokers, ages 50-69 years, enrolled in the Alpha-Tocopherol, Beta Carotene Cancer Prevention (ATBC) Study. After an average of 10 years of follow-up, 1,442 lung cancer cases were diagnosed. Cox proportional hazards models were used to estimate the relative risk (RR) and 95% confidence intervals (CI) of lung cancer associated with self-reported occupational and leisure-time activity, adjusted for age, supplement group, body mass index, cigarettes smoked daily, years of smoking, education, energy intake and vegetable intake. There were no associations between occupational, leisure-time or combined categories of physical activity with lung cancer risk; however, age appeared to modify the effect of leisure-time activity (p = 0.02). Within increasing quartiles of age, the RRs (CI) for men active in leisure time compared to sedentary men were 0.77 (0.54-1.09), 0.74 (0.57-0.95), 1.09 (0.89-1.33) and 1.03 (0.88-1.21). These data suggest that among smokers, neither occupational nor leisure-time activity is associated with lung cancer risk. There may, however, be some modest risk reduction associated with leisure activity among younger smokers. Published 2002 Wiley-Liss, Inc.

Age Factors↗

PubMed2002

Adenomatous polyp recurrence and physical activity in the Polyp Prevention Trial (United States).

OBJECTIVE: To examine prospectively the association between physical activity and adenomatous polyp recurrence. METHODS: Information on past year total physical activity was collected annually through an interview-administered questionnaire from the 1905 men and women enrolled in a randomized dietary intervention study, the Polyp Prevention Trial. Multiple logistic regression analysis was used to examine the association between physical activity and polyp recurrence in up to three years of follow-up from baseline colonoscopy. RESULTS: There were no significant associations between moderate, vigorous, or total physical activity at the start of the trial and overall polyp recurrence in either men or women. Participants who reported consistent vigorous activity throughout the trial period had no significantly reduced risk of polyp recurrence compared to those who reported consistent sedentary activity (OR = 0.8, CI = 0.5-1.1). Consistent vigorous activity was also not significantly associated with either advanced or multiple polyps, nor with polyp recurrence at any specific anatomical location in the large bowel. CONCLUSIONS: These prospective data suggest that recent physical activity is not associated with polyp recurrence in a three-year period.

Adenomatous Polyps↗

PubMed2002

Helicobacter pylori seropositivity and colorectal cancer risk: a prospective study of male smokers.

Because Helicobacter pylori colonization can produce systemic as well as local effects, it may be associated with carcinogenesis in extra gastric target organs. The currently available data regarding a possible link between H. pylori seropositivity and colorectal cancer risk are limited and inconclusive. In this prospective case-control study nested within the Alpha-Tocopherol, Beta-Carotene Study cohort of Finnish male smokers aged 50-69 years, we examined the association between H. pylori seropositivity and incident colorectal adenocarcinoma. Separate risk estimates were derived by colorectal cancer anatomical subsite and by H. pylori CagA seropositivity status. Demographic, dietary, and lifestyle variables were accounted for in the data analyses using information obtained from a prerandomization questionnaire and physical examination. Baseline serum samples from 118 cases and 236 matched controls were assayed for both H. pylori whole cell and H. pylori CagA antibodies. In total, 258 (73%) and 212 (60%) subjects expressed whole cell and CagA antibodies, respectively. H. pylori seropositivity, defined as one or both antibody assays positive, was present in 273 (77%) subjects. None of the seropositivity results were statistically different between cases and controls. Multivariate odds ratio (95% confidence interval) estimates for whole cell, cagA, and H. pylori seropositivity were 1.05 (0.63-1.74), 1.17 (0.74-1.84), and 0.91 (0.53-1.55), respectively. Stratification by colorectal cancer subsite yielded similarly unremarkable results. On the basis of these data, H. pylori carriage does not appear to be an important risk factor for colorectal adenocarcinoma.

Adenocarcinoma↗