Association of the preoperative triglyceride-glucose index with 5-year all-cause mortality after colorectal cancer surgery: a retrospective cohort study

Abstract Background The association between the preoperative triglyceride-glucose (TyG) index and survival after colorectal cancer (CRC) surgery remains uncertain because recent studies have reported opposite associations. We examined the association between preoperative TyG and 5-year all-cause mortality after CRC surgery. Methods This retrospective cohort study included 492 patients with pathologically confirmed colorectal adenocarcinoma who underwent surgery at Central Theater Command General Hospital between 2015 and 2020. The TyG index was calculated from preoperative fasting triglyceride and fasting plasma glucose concentrations. The primary analysis used TyG per 1-standard deviation (SD) increase, and secondary analyses used TyG quartiles. Cox proportional hazards regression was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). Restricted cubic splines were used to assess nonlinearity. We also performed subgroup analyses, proportional hazards tests, and sensitivity analyses. Results During the 5-year follow-up period, 121 deaths occurred among 492 patients. In the fully adjusted model, each 1-SD increase in TyG was associated with a higher hazard of all-cause mortality (HR 1.29, 95% CI 1.06–1.57; P = 0.011). Compared with the lowest TyG quartile, the highest quartile had a higher mortality hazard (HR 1.90, 95% CI 1.08–3.35; P = 0.026), and the trend across quartiles was significant (P for trend = 0.027). Restricted cubic spline analysis showed no evidence of nonlinearity (P for nonlinearity = 0.829). Similar estimates were seen after restricting the analysis to elective surgery, stratifying the Cox model by sex, and adding inflammatory or nutritional measures one at a time. No subgroup interaction was statistically significant. Conclusions Higher preoperative TyG was associated with a higher hazard of 5-year all-cause mortality after colorectal cancer surgery. Similar estimates were seen in the sensitivity analyses. Larger prospective multicenter studies are needed to confirm these findings.