Lower back pain is a broad yet subtle subject. It has widely been associated with early degeneration of the discs of the human spine. Now the EU-funded project Genodisc, completed in 2013 and currently in the data analysis phase, is investigating the correlation between lower back pain and our genes. Project coordinator Jill Urban, university research lecturer in the Department of Physiology, Anatomy and Genetics at the University of Oxford in the UK, talks to youris.com about the misconceptions surrounding back pain and its link to genetics.
What are the misconceptions surrounding back pain?
The mythology is that lower back pain is associated with early disc degeneration. There is certainly a link. But there are many people out there who have bad discs but whose backs are fine. We want to know more about why some people don't get back pain, when their physiology suggests they should.
What does back pain have to do with genetics?
One major breakthrough in our understanding of back pain is our growing awareness that injury to the spine is only part of the story. We have known for 20 years, from studies of twins in Finland, that people with the same genes can have similar spine condition despite doing work which puts different strain on their backs. This result has been replicated in London and elsewhere. It suggests that there is a strong genetic component to lower back pain. We are now looking for the genes responsible. Progress is now being made in identifying candidate genes for painful disc degeneration.
How did you find these results?
Our first aim was to investigate the link between the pain and the patient's condition. To do this we used MRI scans and sampled their disc material. Then we gathered blood from the patients to carry out a genetic analysis. This part of the project, a detailed look at patient DNA, is still continuing.
What are the challenges involved in finding the responsible genes?
One problem is that back pain is a complex disorder, which will certainly involve many genes. At the moment, we are working blindfold. Back pain is a very broad term. It's like having a cough: it could be a cold, or it could be lung cancer. The idea is to find the genes that suggest a cellular pathway that leads to painful disc degeneration.
Part of the problem is that despite its prevalence, lower back pain is an under-researched field of human physiology. If you searched the scientific literature, you would probably find about 1,000 papers on the intervertebral spinal disc. You would find perhaps 150,000 on the kidney. One result of this low level of original research is that for many years, surgeons, rather than scientists, have dominated the field. They tend to be people who want to operate and put in bits of steel. It is only in the past 15 years or less that we have taken a more biological approach.
Does the lack of research interest into lower back pain surprise you?
Yes. Indeed the authoritative Global Burden of Disease survey finds that over 10% of humanity's years of disability are caused by lower back pain. So the image of back pain as a 'malingerer's disease' is outdated and inaccurate.
Does any of the research translate into health advice?
Although our knowledge of the genes associated with low back pain is at an early stage, we already know something about maintaining spinal health. Because your spine is literally central to your body, people are afraid of injuring it. But we are becoming more aware that exercise is always good for the back.