Blocking production of obesity-related hormone could counter type 2 diabetes

Researchers have discovered that a specific hormone in brown fat is elevated in obese people. Known as peripheral serotoni, it inhibits brown fat activity and accelerates the development of obesity and type 2 diabetes.
The study, conducted by researchers at the Michael G. DeGroote School of Medicine and co-director of the Metabolism and Childhood Obesity Research Program at McMaster University in Ontario, was published in Nature Medicine.
Serotonin is a chemical created by the body to relay signals from one area of the brain to another. The most well-known type of serotonin is the one that affects mood and appetite, only accounts for approximately five per cent of the body’s total serotonin.
The rest is peripheral serotonin. It circulates in the blood, and, according to researchers, it reduces brown fat activity. Blocking the creation of peripheral serotonin makes brown fat more active, the study found.
The researchers discovered that most serotonin is produced by an enzyme known as tryptophan hydroxylase (or Tph1). Removing Tph1 in mice that were fed a high-fat diet improved their ability to burn more calories through brown fat. Consequently, the mice were protected from obesity, fatty liver disease, and prediabetes.
Professor Gregory Steinberg, lead author of the study, explained: “Our results are quite striking, and indicate that inhibiting the production of this hormone may be very effective for reversing obesity and related metabolic diseases including diabetes.”
Brown fat is a beneficial form of fat. It burns energy and glucose to create heat. Inactive brown fat means less burning of glucose and energy, and this increases the risk of obesity and type 2 diabetes.