Rapid or significant weight loss through dieting can trigger bone loss. Loss of bone density, in turn, can lead to increased susceptibility to bone fractures in older adults, which can have a debilitating effect on quality of life.
The bone loss is most concerning in people whose weight fluctuates due to
«Weight loss is generally good for you if you are seriously overweight, but bone loss can cause significant problems later in life," said Iwaniec, whose research focuses on metabolic bone disease and bone health. «What we are trying to determine is whether there is a way to lose excessive weight while preserving bone density.»
In the study, rats who received leptin had a weight reduction of about 20 percent, but they did not have any bone loss. The rats that lost weight were able to maintain that weight loss. They also had large reductions of abdominal fat, also known as «bad» fat, which is known to contribute to
The findings were published this week in the Journal of Endocrinology.
Leptin is required for normal skeletal growth and maintenance. The hormone also plays a significant role in the body’s ability to maintain weight, telling your brain how much fat you have and if fat stores are sufficient. But people appear to develop leptin resistance with weight gain, and the brain no longer receives accurate messages, Iwaniec said.
«Using leptin at the level of the hypothalamus to control weight is where, at some point, we believe we’re going to be able to control weight gain," she said. «When the brain tells us to lose weight, it works. When we try to lose weight and the brain tells us not to, it doesn’t work.»
To better understand the role of leptin in both weight and bone loss, researchers injected the gene for leptin directly into the hypothalamus of rats and analyzed the effects on their weight and bones. Injecting the leptin into the brain allows the hormone to bypass the
But this type of gene therapy, which is essentially permanent, may have other risks or
«This kind of therapy has the potential for being far less invasive than something like bariatric surgery," Turner said. «But it’s forever. It seems like a very extreme procedure, from that standpoint.»
Editor’s Note: This research was supported by the National Institute of Arthritis and Musculoskeletal and Skin Diseases of the National Institutes of Health under grant number R01AR060913.
