Clinical implication of elevated CA 19-9 level and the relationship with glucose control state in patients with type 2 diabetes

The aim is to investigate whether there is a difference in CA 19-9 levels between diabetes and healthy subjects except malignancies and associated factors with CA 19-9 in diabetes. We performed a retrospective analysis in 146 type 2 diabetes and 154 healthy subjects who visited our medical institution from 2005 to 2009. We compared the CA 19-9 in each group, and analyzed clinical and biochemical variables in diabetes. The average value of CA 19-9 in diabetes was higher than that of healthy subjects significantly (14.1 vs 8.1 U/mL, p < 0.01). CA 19-9 had a positive correlation with HbA1c (r = 0.22), fasting plasma glucose (r = 0.24), and C-reactive protein (r = 0.38) in diabetes (p < 0.05). 48 type 2 diabetes who showed decreased CA 19-9 during follow-up of 1.8 ± 1.0 years were also improved in glucose control state. The proportion of insulin use for glucose control was significantly higher in the group of CA 19-9 ≥ 37 U/mL (75.0 %) as compared with the group of CA 19-9 < 37 U/mL (34.0 %). CA 19-9 was significantly higher in the patients with diabetic peripheral neuropathy (DPN) as compared with those without DPN (p = 0.02). However, after excluding the influences from glycemic control state, significant difference was not observed. Our results indicate not only that CA 19-9 is influenced by glycemic control state but also can be elevated irrespective of any malignancy in diabetes. Therefore, CA 19-9 should be interpreted carefully in diabetic patients when CA 19-9 is used as the tool for malignancy screening.