Colorectal Cancer Risks According to Sex Differences in Patients With Type II Diabetes Mellitus: A Korean Nationwide Population-Based Cohort Study.

INTRODUCTION

Developing colorectal cancer (CRC) poses challenges for patients with type II diabetes mellitus (T2DM). We investigated CRC risk factors in patients with T2DM.

METHODS

We retrospectively collected data from the National Health Insurance Corporation database, comprising approximately 97% of the Korean population. T2DM and CRC were defined according to International Classification of Disease codes (10th Revision) and claims data. Obesity was defined using body mass index (BMI); abdominal obesity was defined according to waist circumference. Other variables were defined using demographic, anthropometric, and laboratory data.

RESULTS

Overall, 2,591,149 patients with T2DM were analyzed. During the follow-up period (median, 5.4 years), 24,236 CRC cases were identified. Aging (≥70 years), male sex, smoking, alcohol consumption, hypertension, and insulin and/or sulfonylurea use were significant risk factors for CRC. In males, smoking and alcohol consumption were more likely to lead to CRC, whereas a BMI increase was a more significant risk factor in females. Females with a BMI ≥ 25 kg/m and abdominal obesity were associated with an 18% increased risk of CRC compared with patients with normal weight and normal waist circumference (hazard ratio = 1.184, 95% confidence interval 1.123-1.25), whereas male patients with a BMI ≥ 25 kg/m and abdominal obesity were associated with an 8% increased risk (hazard ratio = 1.087, 95% confidence interval 1.049-1.127).

DISCUSSION

Patients had CRC risk factors that differed according to sex. Smoking and heavy alcohol consumption were risks of CRC in males. Female patients with a BMI ≥ 25 kg/m and abdominal obesity were at a higher risk of developing CRC than males.