Association of Elevated Serum Triglycerides with Colorectal Cancer Risk: Findings from a Large-Scale Prospective...

Colorectal cancer (CRC) incidence is rising in Korea, emphasizing the need to identify its risk factors. Serum lipids may influence CRC risk, but evidence is conflicting. We examined the associations between serum lipids and CRC risk in Koreans. Using data from Korean Genome and Epidemiology Study Health Examinee study, we assessed serum low-density lipoproteins (LDL), high-density lipoproteins (HDL), triglycerides (TG) and total cholesterol (TC) among those who did not use lipid-lowering drugs. Dyslipidemia and its subcategories were defined using established clinical thresholds. Cancer cases were identified via the national cancer registry. Associations between lipids and cancers were evaluated using Cox regression. Subgroup analyses were conducted by sex, age, diabetes, and prior screening experience, along with sensitivity analyses based on follow-up duration. During a median follow-up of 9.1-years, 821 new CRC cases occurred among 111,330 participants aged 40-69 years (38,455 men and 72,875 women). For CRC, elevated TG (Q4 vs. Q1 HR 1.32, 95% CI: 1.07-1.62; P-trend = 0.02) and TC (Q4 vs. Q1 HR 1.22, 95% CI: 1.00-1.51) increased risk. For colon cancer, high TG increased risk (Q4 vs. Q1 HR 1.42, 95% CI: 1.08-1.86, P-trend=0.01). Those with hyper-triglyceridemia, compared those without, showed increased risk (HR 1.42, 95% CI: 1.07-1.87) for rectal cancer, whereas other lipids showed no significant associations. Similar but attenuated results were found in the subgroup analyses among participants aged ≥50 years. TG was associated with colorectal, colon, and rectal cancer in Koreans. Findings suggest that lipid levels may be relevant to CRC prevention strategies.