Vitamin D3 expression in patients with type 2 diabetes mellitus complicated by colorectal polyps and colorectal cancer

Objective To study the expression of vitamin D3 in type 2 diabetes mellitus patients with poor glycemic control complicated by colorectal cancer or colorectal polyps. Methods A total of 120 patients with type 2 diabetes were selected as the research objects. According to the diagnostic standard for blood glucose control and diagnosis of colorectal polyps/colorectal cancer, the 120 patients were divided into two groups: type 2 diabetes with poor glycemic control group [glycosylated hemoglobin A1 c (HbA1c>6.5%)], type 2 diabetes with good glycemic control group (HbA1c<6.5%). In type 2 diabetes with poor glycemic control group, 30 cases with colorectal polyps were further allocated to group A, and 30 cases with colorectal cancer were allocated to group B; in type 2 diabetes with good glycemic control group, 30 cases with colorectal polyps were allocated to group C, and 30 cases with colorectal cancer were allocated to group D. Sixty patients without diabetes in the same period were selected as non diabetic group (30 cases with colorectal polyps were set up as group E, and 30 cases with colorectal cancer were set up as group F). 1, 25-dihydroxyvitamin D3 [1, 25-(OH)2-VD3], blood glucose and HbA1c in subjects were detected, and each patient underwent gastrointestinal endoscopy. The relationship between serum 1, 25-(OH)2-VD3 and HbA1c, fasting blood glucose was observed; and the relationship between serum 1, 25-(OH)2-VD3 and insulin resistance was analyzed. The occurrence of colorectal polyps or colorectal cancer in type 2 diabetes patients with poor glycemic control of different 1, 25-(OH)2-VD3 levels was observed. Results There were significant differences in 1, 25-(OH)2-VD3, fasting blood glucose and HbA1c expression among each group (P<0.05). The levels of HbA1c and fasting blood glucose in group B, D, F were higher than those in group A, C and E, respectively (P<0.05); the 1, 25-(OH)2-VD3 levels in group B, D, F were lower than those in group A, C, E (P<0.05). There were negative correlations among serum 1, 25-(OH)2-VD3 with HbA1c, fasting blood glucose (P<0.05). There were significant differences in serum 1, 25-(OH)2-VD3 level and insulin resistance related indexes among each group (P<0.05). There were positive correlations among 1, 25-(OH)2-VD3, homeostasis model assessment-β (HOMA-β), insulin sensitivity index (P<0.05); and 1, 25-(OH)2-VD3 was negatively correlated with HOMA-IR and insulin (P<0.05). The proportion of colorectal polyps or colorectal cancer in type 2 diabetes mellitus patients with 1, 25-(OH)2-VD3 deficiency[1, 25-(OH)2-VD3 <25 g/L] and poor glycemic control was higher than that of paithes with 1, 25-(OH)2-VD3 levels more than 25 g/L, the difference was significant (P<0.05). Conclusions The expression of 1, 25-(OH)2-VD3 level is low in type 2 diabetes patients with poor glycemic control and colorectal polyps or colorectal cancer. 1, 25-(OH)2-VD3 is negatively correlated with glycemic control in patients with type 2 diabetes complicated by colorectal polyps or colorectal cancer, and has good correlation with insulin resistance related indicators. The probability of development of colorectal polyps or colorectal cancer may increase in patients with type 2 diabetes mellitus complicated by 1, 25-(OH)2-VD3 deficiency and poor glycemic control. Key words: Type 2 diabetes mellitus; Colorectal polyps; Colorectal cancer; 1, 25- dihydroxyvitamin D3