The Correlation Between Type 2 Diabetes Associated Diarrhea And Changes Of Enteric Nervous System

BACKGROUND AND AIMWith the development of economy and the change of life style, the total number of diabetic patients in China, one of the three largest number countries around the world, is rising year by year. Now, diabetes has become a public health problem which is concerned by the whole world. Diabetes is a chronic systemic metabolic diseases and it can cause various acute or chronic complications, which seriously affect the quality of the patients'life. Gastrointestinal complication is a common chronic complication occurring in type 2 diabetic patients, especially in who with long disease duration or long-term use of oral glucose-lowering drugs. It includes gastroparesis, abdominal pain, diarrhea and constipation, among which diarrhea accounts for approximately 5.3%.At present, the pathogenesis about type 2 diabetes associated diarrhea were unclear, preious research mostly focused on autonomic neuropathy and gastrointestinal hormones.The research on the correlation between enteric nervous system, which plays an important role in gastrointestinal functional adjustment, and diabetes is rare. This study investigated the correlation between type 2 diabetes associated diarrhea and changes of enteric nervous system in order to provide a new thought on early diagnosis and treatment of diabetic colon dysfunction.MATERIALS AND METHODS Fourteen patients with type 2 diabetes who underwent colonoscopy because of diarrhea symptoms were chosen as the research objects.Ten nondiabetic patients with normal colon undergoing colonoscopy because of other reasons were elected as the control group. Each patient was taken 3-5 mucosal biopsy samples on the junction of the sigmoid colon and rectum. Intestinal mucosa nerve plexus ultrastructural changes were observed by electric microscope. Structural changes of bowel nerve plexus were observed by using neuron specific protein gene product 9.5(PGP9.5) immunohistochemical method.RESULTSThe colonic mucosa in research group had some changes such as nerve fiber bundle neuraxial cavity cavitation, the cytoplasmic matrix of schwann cells appearing low density, and the membrane of the unmyelinated nerve fibers thickening. There were no significant changes in the control group. After marking the nerve fibers of colonic mucosa by PGP9.5.The average percentage of the PGP9.5 positive area in epithelium and interstitium of the mucosal plexus in research group was significantly larger than that in control group (4.13%±1.12% vs.2.18%±1.01%, P<0.01)CONCLUSION 1. Type 2 diabetes induced diarrhea may cause changes of mucosal plexus ultrastructure such as changes of quantity and morphous of intestinal nerve fibers.2. The changes such as mucosal plexus ultrastructure, quantity and morphous of intestinal nerve fibers may be involved in generation of diarrhea symptoms in type 2 diabetes. Enteric nervous system may has morphological and neural chemical changes because of ultrastructural changes, which would lead to feeling, and other dysfunction of intestinal movement, consequently coming to diarrhea. Increased number of nerve fiber may due to reactive hyperplasia. More nerve fibers can secrete excessive neurotransmitters and cell factors, which were combined with increased nerve impulse transmission, to promote intestinal movement and secretion, and further the diabetic related diarrhea generation.SIGNIFICANCEDiarrhea in type 2 diabetes can lead to disorder of water and electrolytes regulation, and can make blood glucose not easy to control, which both can aggravate the severity of diabetes. Finding out how enteric nervous system participates in the generation of diabetes related diarrhea will benefit diabetic patients of type 2 suffering from diarrhea during the treatment process.