Associations between nutritional indices and self-reported history of colorectal cancer in middle‑aged and older adults: a cross‑sectional study based on NHANES 1999–2020

This study aimed to investigate the association between nutritional indices (i.e., the Geriatric Nutritional Risk Index [GNRI], Prognostic Nutritional Index [PNI], Advanced Lung Cancer Inflammation Index [ALI], and the Controlling Nutritional Status [CONUT]) and a self-reported history of colorectal cancer (CRC) using data from the National Health and Nutrition Examination Survey (NHANES) 1999–2020. Weighted multivariate logistic regression was employed to evaluate the associations of GNRI, PNI, ALI, and CONUT with a self-reported history of CRC. Restricted cubic spline (RCS) analysis was used to examine dose–response relationships. Subgroup analyses were performed to test for potential effect modifications. Propensity score matching (PSM) was applied to balance baseline characteristics in sensitivity analyses, ensuring the robustness of the results. Among 25,169 eligible participants, 327 (1.3%) had a self-reported history of CRC. Weighted logistic regression revealed that PNI (OR = 0.957, 95% CI: 0.925–0.990) was negatively associated with a self-reported history of CRC, whereas CONUT was positively associated (OR = 1.274, 95% CI: 1.156–1.404). Both GNRI and PNI demonstrated nonlinear negative relationships ( P for nonlinear = 0.010 and 0.019, respectively). Exploratory subgroup analyses suggested potential effect modifications by diabetes for GNRI and by sex for CONUT. The inverse association was seemingly stronger in diabetic participants, and the positive association was seemingly stronger in females. Sensitivity analyses after PSM confirmed the stability of these findings. GNRI, PNI, and CONUT were associated with a self-reported history of CRC in middle-aged and older adults, suggesting a link between systemic immunonutritional status and a self-reported history of CRC.