Serum lipids and left-sided adenomas of the large bowel: an extended study of self-defense officials in Japan

In the on-going study of men retiring from the Self-Defense Forces in Japan, we previously reported that serum total cholesterol was not related to colorectal adenomas but that men with low levels of serum highdensity lipoprotein (HDL) cholesterol had an elevated adenoma risk. We examined whether the previous observation was reproducible in a different set of data accrued subsequently in the study. Serum total cholesterol, HDL-cholesterol, low-density lipoprotein (LDL) cholesterol, and triglycerides were compared between 138 cases of colorectal adenomas at the depth of 60 cm or less from the anus and 909 controls with normal sigmoidoscopy in the period from October 1988 to December 1990. There was virtually no relation between adenoma risk and any of the serum lipids studied with or without adjustment for smoking, alcohol use, and body mass index. In the analysis combining the earlier and present data, however, men with large adenomas (≥10 mm, n=25) tended to have lower levels of total cholesterol and LDL-cholesterol compared with controls (n=1,612); adjusted mean differences were −0.21 mmol/l (P=0.24) and −0.26 mmol/l (P=0.13), respectively. These findings are inconclusive, but hypocholesterolemia may be associated with the growth of colorectal adenoma.