Adding to the already length list of reasons not to smoke, researchers have connected smoking to worsening degenerative disc disease in the cervical spine, according to research presented this week at the Association of Academic Physiatrists Annual Meeting in Sacramento, Calif.
The cervical spine is located in the neck and is made up of bones called vertebrae. Between these bones are cervical discs that absorb shock to the spine. Through the normal aging process, these discs slowly degenerate, which means they become dehydrated and shrink. This may result in a person experiencing chronic neck pain that may be difficult to treat. In some cases, the drying of the disc may result in the formation of cracks and tears, through which some of the jelly-like central portion of the disc may spill out and irritate local nerves, which much of the time results in pain in the shoulders, arms, hands and fingers.
It isn't only wear and tear over time that can damage these discs. Some unhealthy habits, such as smoking, can add to cervical disc degeneration, according to Mitchel Leavitt, MD; resident physician at Emory University's Department of Physical Medicine and Rehabilitation and the lead investigator of a new study looking at smoking and cervical disc disease. "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," Dr. Leavitt explains. "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 (toward the base of the spine), no studies have been able to make this association with the cervical spine. To address this, Dr. Leavitt's team evaluated the CT scans of 182 consecutive patients who were scanned for various reasons.
"There are more and more high-quality studies coming out that show an association between healthy lifestyle and improved quality and quantity of life as well as better disease management. Spine health is no different, and this study adds to existing studies that have looked at blood vessel health as it relates to chronic back pain," Dr. Leavitt says.
The patients evaluated by Dr. Leavitt's team were mostly female (57 percent), and 34 percent were smokers. The researchers utilized a radiologist with subspecialty training in neuroradiology and a physiatrist - a physician who specializes 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 (one to 33 percent loss of disc height), moderate (34 to 66 percent loss of disc height), or severe with (greater than 66 percent loss of disc height or having a condition called vacuum disc where gas has accumulated in the discs). Based on this, scores of zero (normal) to three (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 zero to 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 (called 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," explains Dr. Leavitt of the study's findings. "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 suggests more research should be conducted on other lifestyle factors (e.g., 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.
"As the population continues to get older, more and more patients are wanting, if not demanding, that they be given the opportunity to be as active as they were in their 40s. They want to play golf, run triathlons, work in their garden, etc.; however, chronic pain originating from the spine makes these activities difficult," says Dr. Leavitt. "Virtually everyone knows that moderate exercise somewhere around four to five times per week is beneficial, plus other lifestyle factors like avoidance of smoking and a proper diet are equally important. However, these topics are usually geared towards heart health, lowering blood pressure, managing diabetes, or controlling other medical conditions, and not specific to the spine. It is one thing to live to the age of 95, and it is another to live to 95 while retaining one's mobility and being free of pain. Lifestyle medicine will likely play a large role in the future of healthcare, and having plenty of data to support lifestyle management is critical for a provider who practices evidenced-based medicine. The lifestyle approach may allow us to not only live longer and healthier lives, but we may also be able to take less medication in the process, thereby sparing us the risk of medication side effects."
Association of Academic Physiatrists (AAP)