Metabolic syndrome and incidence of liver and breast cancers in Japan

Aim of the study To clarify the relationship between the presence of metabolic syndrome and the incidence of cancer in a general Japanese population. Methods A retrospective cohort study was conducted among 8329 male and 15,386 female subjects between 1992 and 2000. The analysis used five definitions of metabolic syndrome. The information on the site-specific cancer was obtained from the population-based cancer registry. A Cox proportional hazard model was adapted for the statistical analyses. The average follow-up period was 9.1 years. Results The National Cholesterol Education Program Adult Treatment Panel III 2001 criteria of metabolic syndrome revealed that the hazard ratio of metabolic syndrome for liver cancer was 1.89 (95% confidence interval (CI) 1.11–3.22) for males, and 3.67 (CI 1.78–7.57) for females. The hazard ratio for female breast cancer was 2.87 (CI 1.67–4.94). When the analysis was limited to postmenopausal women (55 years of age or older), the ratio increased to 6.73 (CI 2.93–15.43). The NCEP-ATPIII 2001 criteria were superior to the other four proposed criteria for predicting the incidence of cancer. In the statistical model, which included all components of the metabolic syndrome and the metabolic syndrome (present or absent), high blood glucose was a significant associated factor for all sites and liver cancers, whereas the metabolic syndrome was found to be a significant associated factor for breast cancer. Conclusion Metabolic syndrome may play an important role in the incidence of breast cancer. High fasting plasma glucose level is considered to be useful as an associated factor for the incidence of all-sites and liver cancer.