Yanan Ma, from China Medical University in Shenyang, and colleagues followed 87,523 women from the Nurses’ Health Study and 47,240 men from the Health Professionals Follow-up Study to examine the correlation of T2D and its duration with the risk for incident CRC.
The researchers documented 3,000 cases of CRC during a follow-up of 32 years. Among men, the risk for CRC was increased for those with versus those without T2D (hazard ratio, 1.42; 95 percent confidence interval, 1.12 to 1.81). The positive association remained in sensitivity analyses excluding CRC identified within one year of diabetes diagnosis and excluding patients with T2D using hypoglycemic medications. Among women, there was a positive but not statistically significant association between T2D and CRC risk (hazard ratio, 1.17; 95 percent confidence interval, 0.98 to 1.39).
“More studies are warranted to further investigate the underlying mechanisms,” the authors write. “Our finding further underscores the importance of enhancing the effort to reduce the emerging epidemics of type 2 diabetes for colorectal cancer prevention and control.”