Popular diabetes drug Avandia linked to osteoporosis

February 27, 2016

The drug Avandia, also known as rosiglitazone, has been found to possibly have links to osteoporosis, a condition which causes bone fragility and bone loss.

Avandia which is manufactured by GlaxoSmithKline, has already been found to raise a patient's risk of heart disease and heart attacks.

According to Professor Ron Evans from the Salk Institute for Biological Studies in La Jolla, California, research on mice given the drug showed an increased production of cells that act to break down bones in the body.

Evans says it was already known that Avandia causes bone loss by inhibiting bone formation, but the study identified an additional mechanism whereby Avandia promotes bone resorption, the process by which osteoclasts break down bone and release minerals.

These apparently are the two parts of a checks-and-balance system that keeps bones healthy and Avandia appears to weaken both sides of the balance mechanism, leading to an increased risk for osteoporosis.

Professor Evans says the long term use of Avandia for people with type 2 diabetes, can lead to bone fragility and osteoporosis.

He says the study has led to a better understanding of the challenges associated with long-term treatment of patients with type 2 diabetes.

Evans also says because Avandia is effective in controlling glucose and restoring the body's sensitivity to insulin, people should not stop their treatment but balance the benefits against the complications.

Worldwide millions of people are living with diabetes and many of them are taking Avandia to help control their blood sugar.

Experts say there are many alternatives and anyone already at risk for osteoporotic fractures should consider an alternative anti-diabetic drug.

The research was funded by the Howard Hughes Medical Institute and the National Institutes of Health and is published in the journal Nature.

The researchers found, as expected, that the healthy volunteers had many more Meissner corpuscles in the tip of the pinkie finger ?? about 12 such structures per square millimeter, compared to a mean of 2.8 in people with neuropathy. Patients with neuropathy also had fewer of the structures at the base of the thumb.

While the results were not surprising, attaining them so easily was. Volunteers simply held their pinkie finger under a microscope for a few minutes. No pain, no blood, no tissue preparation.

In an editorial about the research, Peter J. Dyck, M.D., of the Mayo Clinic wrote in the journal, ???The approach may find use as the gold standard of tactile sensation and of large fiber sensorimotor polyneuropathy.??? But he also pointed out some limitations of the work. Dyck said the technique needs to be tested in greater numbers of people, pointed out that the equipment needed for reflectance confocal microscopy is expensive, and mentioned the need to differentiate between healthy and abnormal Meissner corpuscles.

An advance in screening would be appreciated by millions of patients. More than half of people with diabetes will eventually develop neuropathy. Most of them won't feel pain ?? they'll simply lose sensation in their feet, making them vulnerable to wounds that can result in severe infections. Oftentimes sensation slips away so gradually that patients don't even notice. A new screening tool would help doctors monitor patients more closely so that both they and patients are aware of nerve damage and can do everything they can to prevent further damage.

???Neuropathy is very difficult to treat, and part of the reason is that currently, we usually identify it too late, after there has been significant damage,??? said Herrmann, director of the Peripheral Neuropathy Service at Strong Memorial Hospital. ???Treatments might be more beneficial if we could detect the condition earlier.

???The idea is to move from an invasive biopsy for monitoring nerve endings, to non-invasive, painless approaches. A person could have this technique done as frequently as is necessary, for instance. That's an attractive notion for tracking the condition of nerves in patients,??? said Herrmann, who is now assessing the technique in 75 people, with funding from the National Institute of Neurological Disorders and Stroke.