BMI-based metabolic syndrome Z-score and gastrointestinal cancers: A cohort study

Obesity is not only an important part of metabolic syndrome, but also closely related to the pathogenesis of a variety of malignancies. However, there are differing views on the relationship between obesity and the risk of digestive malignancies. In this context, it is necessary to assess the true cancer risk in people with different obesity states. In the past, some researchers proposed to use the metabolic syndrome severity z score to predict the risk of certain diseases, but since its introduction, there has been a lack of relevant studies in the Chinese population. Based on the Kailuan cohort, the association between metabolic syndrome severity z score and the risk of digestive system malignancy in the Chinese population was explored. In this study, 48,205 participants who had undergone 3 consecutive physical examinations since 2006 were collected. Cumulative metabolic syndrome severity z score (cMets-Z) was calculated using parameters such as fasting blood glucose, total cholesterol, high-density lipoprotein, systolic blood pressure, and body mass index. Participants were categorized into 4 groups based on cMetS-Z (Q1-Q4), and a Cox regression model was used to evaluate the risk of new digestive system malignancies. The mean age of participants was 48.99 ± 11.75 years. Over a median follow-up period of 11.03 years, 749 new cases of digestive cancers were identified, including esophageal, gastric, colorectal, liver, bile duct, and pancreatic cancers. Cox proportional hazards modeling revealed adjusted hazard ratios for gastrointestinal cancers in the Q2 to Q4 groups as 1.19 (0.96-1.48), 1.36 (1.08-1.71), and 1.72 (1.33-2.23). In site-specific analyses, we observed that this risk was more pronounced in esophageal cancer. Subgroup analyses showed that cMetS-Z was associated with digestive system malignancies, particularly in male participants with metabolic syndrome. Restricted cubic spline regresion results showed that cMets-Z had a linear relationship with the risk of digestive system tumors. We found that cMetS-Z was associated with an increased risk of gastrointestinal cancer. cMetS-Z can be used as a prospective tool to predict the risk of gastrointestinal malignancies in Chinese people.