Association of the triglyceride-glucose index with multiple colorectal polyps as a precursor-lesion burden phenotype in adults undergoing diagnostic colonoscopy

Colorectal cancer prevention depends on detection of precursor lesions, and metabolic dysfunction may shape early colorectal neoplasia before invasive cancer develops. Evidence linking the fasting triglyceride-glucose (TyG) index with colonoscopy-defined polyp burden in younger and middle-aged diagnostic populations remains limited. This retrospective single-center cross-sectional study included 169 adults aged 18 to 59 years who underwent complete diagnostic colonoscopy and had fasting triglyceride and glucose measurements within 90 days beforehand. Patients had no polyps ( n = 58), 1 to 2 polyps ( n = 60), or 3 or more polyps ( n = 51); the primary outcome was 3 or more polyps. Logistic regression assessed TyG continuously and by tertiles, adjusting for age, sex, body mass index category, hypertension, and ever smoking. Spline modeling, discrimination, calibration, and E-value analyses were performed. Sensitivity analyses added diet, physical activity, alcohol use, family history, and colonoscopy-quality indicators; exploratory analyses examined incremental value over conventional risk factors and 2-hour postprandial glucose. Mean TyG increased across polyp-burden groups (8.44 +/- 0.52, 8.72 +/- 0.51, and 8.90 +/- 0.49; P < 0.001). Each 1-unit increase was associated with higher adjusted odds of multiple polyps (adjusted odds ratio [aOR], 2.41; 95% confidence interval [CI], 1.54 to 3.77; P = 0.002), and the highest tertile with substantially higher odds than the lowest (aOR, 4.78; 95% CI, 2.00 to 11.41; P = 0.005). Discrimination was only fair (area under the curve, 0.678). After further adjustment for diet, physical activity, alcohol use, family history, and colonoscopy-quality indicators, the association attenuated and lost significance (aOR, 1.63; 95% CI, 0.97 to 2.73; P = 0.064). Adding TyG to conventional risk factors raised discrimination only from 0.754 to 0.781. Higher fasting TyG was associated with multiple colorectal polyps in adults undergoing diagnostic colonoscopy, although much of this association was shared with dietary pattern and physical activity. TyG is best regarded as a metabolic correlate of precursor-lesion burden rather than an independent determinant, and its fair discrimination and small incremental value preclude stand-alone triage use. Prospective multiethnic validation with standardized lifestyle assessment and dynamic glycemic measures is warranted.