Scientists have pinpointed a hormone which prevents bone loss in the body.
Osteoporosis weakens the bones
They hope the discovery could lead to new treatment for the brittle bone disease osteoporosis.
The hormone, amylin, is secreted by the same cells that produce insulin in the pancreas, and whose failure leads to diabetes.
The research by, Baylor College of Medicine, is published in the Journal of Cell Biology.
Osteoporosis is caused by loss of mineral density in the bones. This makes them weaker, and more prone to fracture.
It often affects post-menopausal women - but a form of the disease is also found in people with type one diabetes.
The researchers found that mice who lack amylin have less bone mass than those who produce the hormone.
It appears to work by reducing the number of cells normally devoted to chewing up bone.
These cells - called osteoclasts - exist because bones stay strong only through a constant recycling in which old bone is broken down, and replaced by new deposits.
However, the delicate balance between breakdown and renewal of bone can be disturbed if the number of osteoclasts is not carefully controlled.
Type one diabetes - and related osteoporosis - are caused by the body's immune system attacking the pancreatic cells that produce both insulin and amylin.
Lead researcher Professor Gerard Karsenty said if scientists could find a way to replace amylin it could provide a way to prevent diabetes-related osteoporosis - and possibly other forms of the condition too.
A spokesman for the National Osteoporosis Society said many new treatments were being developed for the disease, and the use of amylin was one of several which held out hope.
"However, these findings are still a long way from a potential application in humans to treat the fragile bone disease."
Eleanor Kennedy, research director for Diabetes UK, said the results of the study were interesting.
But she added: "The work was done in mice and there is still little definitive evidence to suggest that people with type one diabetes suffer from lower bone density due to a lack of amylin."