Metabolic syndrome and colorectal cancer: Mechanisms, epidemiological evidence, and clinical implications

Table 1 Summary of key epidemiological studies evaluating the association between metabolic syndrome components and colorectal cancer risk

Ref.	Year	Study design/population	MetS definition/components analyzed	Main findings on CRC risk
Han et al[2]	2021	Systematic review and meta-analysis (17 studies)	NCEP ATP III/multiple components	MetS associated with approximately 30% increased CRC incidence; abdominal obesity and hyperglycemia strongest drivers
Shen et al[4]	2021	Systematic review and meta-analysis (25 cohorts)	Mixed definitions	MetS increased CRC risk (RR approximately of 1.37); stronger effect in men; heterogeneity by region
Zhan et al[7]	2024	Meta-analysis (31 cohorts + MR)	Standardized criteria	MetS and abdominal obesity causally linked to CRC; hyperglycemia consistently associated
Wang et al[8]	2024	Prospective cohort, China (number approximately 100000)	Chinese criteria	MetS significantly increased CRC incidence; abdominal obesity main contributor
Yuan et al[9]	2024	Mendelian randomization	Genetic instruments for MetS	Causal effect of abdominal obesity on CRC risk confirmed
Stocks et al[13]	2008	Prospective cohort, Europe (number approximately 560000; men and women)	MetS components separately analyzed	Abdominal obesity and hyperglycemia increased CRC risk in both sexes; stronger in men
Bhome et a[14]	2021	Prospective cohort, United Kingdom (n = 1006 CRC patients)	Clinical diagnosis of MetS	MetS predicted higher recurrence risk, especially liver-specific recurrence

MR: Mendelian randomization; CRC: Colorectal cancer; MetS: Metabolic syndrome; NCEP: National Cholesterol Education Program; ATP III: Adult Treatment Panel III; RR: Relative risk.