These days, back pain is a very common disorder alongside back of knee pain, afflicting a large proportion of society, both young and old alike.
The Global Burden of Disease Study of 2010 (1) estimated that back pain is in the top 10 diseases and injuries worldwide. Increasing in occurrence predominantly in the Western countries, it is one of the major causes of disability for working people. Several risk factors have been identified, such as obesity, height, occupational posture, age, and depressive moods. But, though very common, opinions are divided among medical professionals as to what causes pain in the spinal discs. The many complicated medical terms used to describe this condition and possible causes, make it more and more difficult for patients to understand.
But, though very common, opinions are divided among medical professionals as to what causes pain in the spinal discs. The many complicated medical terms used to describe this condition and possible causes, make it more and more difficult for patients to understand.
Back pain and back of knee pain
Back pain is also correlated to back of knee pain, leading to a wider array of problems, though most patients do not consider this. When knees start hurting, people believe doctors should look there for a cause. This is not always the case. Primarily due to bad posture and obesity, the muscles attached to the lower back, the psoas, pull tight, creating a great deal of tension in the pelvis, thus affecting the knees.
Being the leading cause of inactivity and inability to work all over the globe, lower back pain (followed by back of knee pain) imposes a high economic burden not only on certain individuals and their families, but also on governments. Most cases of people with LDD require a costly medical treatment while not being able to work and produce an income. Patients are usually past the analgesics, physical therapy and spinal manipulation recommended as a treatment.
Directing efforts to areas that will help many people is crucial. So are research grants. Up until now, while back of knee pain and chronic back pain were an important issue, they haven’t had a great amount of research funding as Alzheimer’s disease or cancer. (2)
People who have deteriorating discs are very susceptible to an increase in the risk of lower back pain episodes, leading to an inability to work or do much of anything else. Chronic pain in the lower back, as well as back of knee pain, are pivotal factors in influencing the well-being of people all over the globe. This is why many studies are currently being performed on what could lead to a better understanding of this malady.
An ‘omics approach to identifying new biomarkers for the problem that is chronic back pain
A study (4) led by Dr. Frances MK Williams from the Department of Twin Research and Epidemiology at King’s College, London, focused on identifying genetic variants (whether single base pair or methylation) accounting for a variation in the phenotype expression of chronic back pain attributed to intervertebral disc degeneration. This study, published in 2012 in the Annals of Rheumatic Diseases, has managed to identify a gene defect that could be linked to vertebral disc complications, leading to chronic back pain.
The study focuses on understanding Lumbar Disc Degeneration, better known as LDD, a problem as costly as it is vital. LDD is characterized by the narrowing of the space between two vertebral discs, followed by a growth of bony protuberances, medically known as osteophytes on its circumference. It is quite common among middle-aged women, a third of them having at least one degenerated disc.
Reports show that the malady could be inherited by up to 80% of clinical patients. The medical director of Arthritis Research UK, Professor Alan Silman, is aware of the fact that lumbar disc degeneration is a habitual cause of lower back pain. He reportedly stated in an interview that this was the first time a gene was ever correlated to this extremely painful and quite disabling medical condition. And this is great news for a large number of people suffering around the world. (3)
All the other studies conducted before have shown either inconclusive, or sometimes conflicting results. Though the studies are hard to replicate, this might be explained by the small number of subjects submitted to testing, as well as the inevitable ethnic differences between Northern European and Asian population.
Funded by the Wellcome Trust, of which Dr. Williams is a fellow, as well as by Arthritis Research UK, and performed on more than 4600 individuals of Northern European descent, this study managed to distinguish a variant in the PARK2 gene, a gene commonly associated with LDD. This study is the first “genome–wide association meta-analysis (GWA) of LDD” (5).
Researchers are confident many more will follow. With a majority of subjects being female, and between 55 and 60 years of age, the study confirms the common presence of Lumbar Disc Degeneration among middle-aged women and further research will most likely find a solution.
As Dr. Williams said in simpler words in a 2008 interview for Arthritis Research UK, the research itself began with a studying of MRI’s from volunteers – healthy twins – that participated in older studies, 10 years prior. This MRI’s were able to share some light on the progression of Degenerative Disc Disorders through the years. At that point in time, the genetic variant could not be named, as a multitude of tests still needed to be performed but Dr. Williams was confident it would be a great find. She stated that it would end up to be her greatest contribution to that point.
Switching off a problematic gene
The researchers working on this study have suggested that the gene could be switched off in people affected by LDD. Professor Alan Silman believes this is a very promising start and that the study has paved the way for many more to come. It would be a paramount long-time goal to identify changes in the DNA and the specific cellular pathways related to LDD. (5) They would lead to a more targeted drug delivery system, as opposed to regular, run of the mill painkillers.
Dr. Williams acknowledges in an interview that, prior to the study, information available relating to human biology and pathogenesis of LDD was incomplete due to the fact that human spinal discs are incredibly hard to get hold of. She has great hope that future research studies conducted on vertebral discs will shed further light on the role held by the PARK2 gene in the case of lower back pain.
All this information, while shedding light on LDD, will help those patients affected by other conditions with strong connection to LDD, such as back of knee pain.