Continuous, but Not Occasional, Oral Ethanol Intake Reduces the Success of Intraportal Transplanted Islets of Langerhans: An Experimental Study

Background: Islet transplantation is gradually gaining acceptance for the treatment of type 1 diabetes mellitus. One of the unknown questions is alcohol intake; we have prohibited alcohol intake after islet transplantation although there is no solid evidence to support this. Materials and Methods: In this study, we employed a mouse model to determine the effect of oral ethanol intake on transplanted islets. Either 500 or 150 islets were infused selectively into the right liver lobe of chemically induced diabetic mice. After transplantation, mice were orally administered either water (as a control) or various concentrations of ethanol for 14 consecutive days occasionally (once per day) or continuously (all intake was alcohol). Blood glucose levels were monitored and oral glucose tolerance tests (OGTT) performed. Results: After 500 islets had been transplanted, all mice were cured from diabetes, but the continuous alcohol intake group showed significantly prolonged time to diabetes reversal and significantly lower glucose clearance rates by OGTT compared with the control group. After 150 islet transplantations, the diabetes cure rate in the continuous alcohol intake group was significantly lower than the control group (continuous alcohol vs control: 3/8 vs 11/12, P < .05). However, the occasional alcohol intake group showed no difference from the control group, even with as few as 150 islets transplanted per mouse. Conclusion: The present results demonstrated that continuous but not occasional alcohol intake reduced the success of intraportal islet transplantation.