Neck and skull x-raySmoking has been linked to a worsening degenerative disc disease in the cervical spine, researchers at Emory University in Atlanta, Georgia, have announced.

The cervical spine is in the neck and made up of vertebrae with discs in between to absorb shock to the spine. The normal ageing process causes these discs to degenerate, becoming dehydrated and ultimately shrinking. The result can be chronic neck pain that is difficult to treat, as well as further additional pain being felt in the shoulders, arms, hands and fingers. 

Yet scientists at Emory University have discovered that external factors, beyond the wear and tear of old age, can also play a part in the degeneration of the cervical discs. For example, smoking can be hugely detrimental to the health of the discs, the researchers announced. 

Mitchel Leavitt, MD; resident physician at Emory University’s Department of Physical Medicine and Rehabilitation and the lead investigator of the study, said: “Smoking is not healthy for a person’s intervertebral discs given the risk of developing microvascular disease – a disease of the small blood vessels – due to nicotine abuse.

“Intervertebral discs receive their nourishment from the microvasculature that line the endplates on either side of each disc; when these blood vessels are damaged, the discs do not receive nourishment and this may speed up the degenerative process.” 

While smoking has been associated with degeneration in the lumbar spine, no studies have been able to make this association with the cervical spine. This new study looked at 182 consecutive CT scans of patients who were scanned for various reasons. 

The patients were mostly female (57%), and 34% were smokers. The researchers utilised a radiologist with subspecialty training in neuroradiology and a physiatrist – a physician who specialises in physical medicine and rehabilitation – to review the CT scans, and they provided documentation on the severity of cervical degenerative disc disease. 

Each disc was rated as normal (no loss of disc height), mild (1%-33% loss of disc height), moderate (34%-66% loss of disc height), or severe (greater than 66% loss of disc height, or having a condition called vacuum disc where gas has accumulated in the discs). Based on this, scores of 0 (normal) to 3 (severe) were given to each disc, and a cumulative cervical degenerative disc disease score was given for the entire cervical spine with a range of 0-15. 

The researchers considered each patient’s smoking status and his or her number of pack years smoked, which is the number of packs of cigarettes the patient smokes each day multiplied by the number of years he or she has smoked. Finally, the researchers collected and considered other health information such as age, body mass index, high blood pressure (hypertension), high cholesterol and diabetes. 

Current smokers were found to have more cervical degenerative disc disease by one point, on average. Additionally, the researchers found that increased age was associated with worsening cervical degenerative disc disease, but co-existing diseases – such as diabetes, hypertension, high cholesterol and high BMI – were not associated with the disease. 

“This is another example of the detrimental effects of smoking. Tobacco abuse is associated with a variety of diseases and death, and there are lifestyle factors associated with chronic neck pain,” explained Dr Leavitt. “Pain and spine clinics are filled with patients who suffer chronic neck and back pain, and this study provides the physician with more ammunition to use when educating them about their need to quit smoking.”

Dr Leavitt suggested more research should be conducted on other lifestyle factors, such as diets high in fat vs. plant-based, alcohol use, obesity, etc as they relate to chronic back and neck pain, as well as identifying any objective changes on advanced imaging or autopsy.