Scientists believe they are closer to pinpointing the exact cause of osteoarthritis, offering the hope of more effective treatment.
A team from the University of Southern Denmark found shortened ends of chromosomes, were linked to the onset of the degenerative disease.
Abnormally short chromosome caps, called telomeres, were seen in cells from damaged knee joints and those near the areas of severe damage were ‘ultra-short’.
These latest findings show that that these lengths of DNA play an integral role in the development of the condition which leads to stiffness and pain in different joints – most commonly in the hands.
It is hoped that this will prompt more effective treatment for osteoarthritis (OA), the most common form of arthritis, for which there is no cure.
Commenting on the findings lead researcher Dr Maria Harbo said: ‘We see both a reduced mean telomere length and an increase in the number of cells with ultra-short telomeres associated with increased severity of OA.’
Researchers studied telomere length in cells taken from the knees of three women with osteoarthritis.
They found that average telomere length was shortened in the affected joints, and telomeres became shorter near the areas of worst damage.
Biological ageing causes the gradual shortening of telomeres – DNA sequences which protect the ends of chromosomes – but a host of other factors can make them shorten over time, including damage caused by oxygen free radicals (oxidative stress).
Oxygen free radicals are the unstable molecules produced as a by-product of normal bodily processes, as well as external factors, such as tobacco, alcohol, and sunlight.
The shortening of telomeres is linked to reduced lifespan, heart disease and osteoarthritis and previous research has shown that preserving the length of these chromosomal ‘bookends’ can increase life expectancy.
People with very long life spans have also been shown to possess longer telomeres.
On the other hand there is evidence that out-of-control telomere recovery may be linked to cancer.
The findings are published in the online journal Arthritis Research & Therapy.
Each year more than 140,000 hip and knee replacement operations are performed on the NHS in England and Wales.
Osteoarthritis usually develops in people over 50 years of age and can be accelerated by previous injury or repetitive stress to joints.
There is no cure for the disease but there is a range of treatments to relieve discomfort.