Researchers at Michigan State University (MSU) are suggesting that leptin may be a cause for compromised immune systems in obese patients. They report that this hormone, which is produced by fat cells, supports white blood cell production in the body.
“The more fat a person has, the more leptin there is in the bloodstream,” explains Pamela Fraker, Ph.D., professor of biochemistry and molecular biology and lead scientist. “In obese people, it seems that the body becomes leptin-resistant. So giving obese people leptin doesn't help them lose weight.”
The MSU scientists were examining ob/ob mice (genetically programmed to have nonfunctional leptin) and db/db mice (genetically programmed to have nonfunctional leptin receptors), giving them supplemental leptin to study its effects. While causing the mice to eat less, those that were given leptin had double the number of B cells.
“This is a brand new role for leptin,” according to Dr. Fraker. “It appears that most obese people may be somewhat immunosuppressed. This finding shows us that the body’s resistance to leptin plays a role in that too.”
The study was reported in this week’s online edition of the Proceedings of the National Academy of Sciences.