Researchers at the Joslin Diabetes Center said their discovery leptin is involved in islet cell growth and insulin secretion might lead to new treatments for diabetes.

Previous in vitro studies suggested leptin receptors, which are found in tissues throughout the body, including the pancreas and the brain, mediate leptin-induced inhibition of insulin secretion in islet cells, also known as beta cells.

"We wanted to further our understanding of leptin and its role in beta cells independent of its effects in the brain," said Dr. Rohit Kulkarni, principal investigator of the study and an assistant professor at Harvard Medical School. It is currently not known why obese individuals exhibit a high incidence of diabetes despite high levels of both insulin and leptin in their bloodstream.

Obesity is a major risk factor for the development of type 2 diabetes, the most common form of the disease.

The study appears in The Journal of Clinical Investigation.