In This Issue of Diabetes

Edited by Helaine E. Resnick, PhD, MPH

Islet Transplant Performance in Type 1 Diabetic Mice Improved by Low-Level Leptin Cotherapy

For the treatment of type 1 diabetes, islet transplantation results in improved glycemic control relative to insulin injection, but the paucity of donor islets and decline of graft function over time are barriers to the widespread implementation of this therapy. In this issue of Diabetes, research in mice by Denroche et al. (p. 2738) shows that effective control of blood glucose can be achieved with a much smaller islet dose if accompanied by low-dose leptin therapy. Using mice with streptozotocin-induced type 1 diabetes and healthy controls, researchers conducted a series of experiments that varied the islet dose—50, 125, or 300 islets (compared to an optimal dose of 300 islets)—and the presence or absence of leptin (1 µg/day, administered via subcutaneous pump). As expected, blood glucose was not significantly lowered in mice receiving only suboptimal islet doses. By contrast, mice receiving 125 islets and leptin maintained glycemic control for the full 40-day study period. At the 125 islet dose, transplant/leptin cotherapy also significantly improved glucose excursions. Plasma insulin concentrations were raised by islet transplantation alone but not by leptin administration alone; because the cotherapy did not further raise insulin levels relative to transplantation without leptin, the authors surmise that, rather than increasing insulin secretion outright, leptin lowers blood glucose by providing a lipid-reducing and more insulin-sensitive environment in which graft-derived insulin can act more effectively. The authors strongly caution against the use of leptin as a monotherapy, noting its decreasing …

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This Article

  1. doi: 10.2337/db13-ti08 Diabetes vol. 62 no. 8 2627-2628
  1. Free via Open Access: OA