Fat clue to leptin resistance

A paper published in the May issue of Diabetes implicates triglycerides in the mechanism of leptin resistance. These fats, elevated in obesity, are what disrupt the transport of the hormone across the blood–brain barrier (BBB) to its site of action in the hypothalamus, according to the study.

The discovery in 1994 of leptin, an appetite-suppressing hormone produced by fat cells, led to hopes that the peptide could be used to treat obesity pharmacologically. However, it soon emerged that most obese people are resistant to leptin rather than deficient in it. Resistance is associated with loss of function at several stages of the leptin-signaling pathway. Leptin's transport across the BBB is impaired, and there is reduced function of the leptin receptor and its downstream targets, said William A. Banks at the Veterans Affairs Medical Center, St. Louis.

Banks, who led the research, said the idea of a role for triglycerides came ...