Smoking has been linked to worsening cervical degenerative disc disease in the cervical spine and can therefore increase the risk of chronic neck pain, according to research presented at the Association of Academic Physiatrists (AAP) 2016 meeting in Sacramento, California.
“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,” said Mitchel Leavitt, MD, resident physician at Emory University’s Department of Physical Medicine and Rehabilitation, in a statement. “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 had yet made this association with the cervical spine.
To evaluate the association between cigarette smoking and cervical degenerative disc disease, the researchers reviewed 182 CT scans of patients (57% women; n = 103) that had been conducted at a university hospital for various reasons. Of the 182 patients, 61 were smokers (34%).
The researchers rated each disk as normal (no loss of disc height), mild (1% to 33% loss of disk height), moderate (34% to 66% loss of disk height), or severe (greater than 66% loss of disc height, or having the condition called vacuum disk in which gas has accumulated in the disks). Numerical scores were given to each disk from 0 (normal) to 3 (severe), and the entire cervical spine was then given a cumulative score ranging from 0 to 15.
The researchers also found each patient’s smoking status and number of pack years smoked (the number of packs smoked a day multiplied by the number of smoking years). The researchers also collected the patients’ age and body mass index, as well as whether or not the patients had high blood pressure, high cholesterol, or diabetes.
The researchers found that current smokers were found to have more severe cervical degenerative disk disease after controlling for age (p=0.0203). Active smokers had a worse cumulative degenerative disk disease score by an average of 1 point. They found no statistical significance for pack years (p=0.164).
Age was also correlated with worsening cervical degenerative disk disease (correlation coefficient 0.636, p < 0.0001). No correlation between worsening cervical degenerative disk disease and the comorbidities of diabetes, hypertension, hyperlipidemia, or high BMI was found.