SERUM-LIPIDS AND ADENOMAS OF THE LEFT COLON AND RECTUM

Levels of serum lipids are partially determined by several established risk factors for colorectal cancer and are themselves potential risk factors for the disease, However, evaluating serum lipids as risk fact ors has proved problematic because metabolic events associated with ma lignant transformation or progression appear to alter serum lipid conc entrations, Serum lipid concentrations are less likely to have altered in individuals with precancerous lesions, such as colorectal adenomas , During 1991-1993, we collected fasting blood samples from and provid ed questionnaires to men and women 50-75 years old, who visited sigmoi doscopy clinics at a health maintenance organization, Serum lipid conc entrations from 486 cases with adenomas and 520 controls were analyzed , Compared to subjects in the lowest quintile of serum triglyceride co ncentrations, subjects in the highest quintile had an adjusted odds ra tio of 1.5 (95% confidence interval, 1.0-2.2), The corresponding odds ratio for total cholesterol was 1.3 (0.9-1.9); for high-density lipopr otein cholesterol, it was 1.1 (0.7-1.6); and for low-density lipoprote in cholesterol, it was 1.1 (0.7-1.6), Further adjustment for potential confounding did not alter these results substantively, although deter minants of serum triglycerides and high-density lipoprotein cholestero l (e.g., obesity, physical activity, and refined carbohydrate and alco hol intake) in this and other studies may not be sufficiently well mea sured to avoid residual confounding, Higher levels of serum triglyceri des are associated with an increased risk of adenomatous polyps. Consi stent with previous studies, serum cholesterol was not inversely relat ed to the risk of colorectal polyps.