The impact of dietary inflammation index on gynecological and breast cancer risk in adult smoking women in the United States: A cross-sectional study based on NHANES data from 2007 to 2020

Gynecologic and breast cancers (GBC) represent one of the most prevalent malignancies among women globally, and the Dietary Inflammation Index (DII) may influence its associated risk. This research aims to investigate the impact of DII on the risk of GBC in adult female smokers in the United States, utilizing National Health And Nutrition Examination Survey data from 2007 to 2020. A descriptive analysis was initially conducted to evaluate the dataset, followed by a binomial logistic regression model to assess the relationship between DII and GBC. Three models were developed: Model I (unadjusted), Model II (adjusted for age, race, education level, and income ratio), and Model III (further adjusted for confounding variables including body mass index, chronic diseases, alcohol consumption, and physical activity). A multifaceted sensitivity analysis was performed to validate the robustness of the findings. The analysis included 7501 participants, of whom 1291 were smokers. Results indicated that a higher DII was significantly associated with increased GBC risk. In Model I, each unit increase in DII corresponded to a 24% increase in risk (Odds ratios [OR]: 1.24, confidence intervals [CI]: 1.07-1.44, P = .005). Model II showed a 32% increase (OR: 1.32, CI: 1.13-1.55, P = .001), while Model III indicated a 27% increase (OR: 1.27, CI: 1.05-1.53, P = .017). Sensitivity analysis revealed no significant effects of DII on former smokers and nonsmokers (P > .05). Additionally, subgroup analysis based on race, education level, income, body mass index, and DII quartiles did not yield significant results (P > .05). Restricted cubic splines analysis did not identify a nonlinear relationship between DII and GBC (P = .307). The DII is significantly associated with the risk of GBC among female smokers, underscoring the necessity of incorporating dietary factors into cancer prevention and intervention strategies.