“We aimed to investigate whether tobacco smoking is an independent risk factor of undergoing surgical intervention for lumbar spinal stenosis,” wrote the team from Umeå University.
They looked at data from 331,941 construction industry workers, which came from a national health survey in Sweden. The data was collected over thirty years, starting from when the workers were in their 30s, and 1,623 went on to have back surgery.
The data illustrated that medium to heavy smokers were 46% more likely to need spinal surgery, light to medium smokers were 31%, and ex-smokers had a 13% elevated risk of needing the procedure.
The paper states that this is an important issue because: “Lumbar spinal stenosis (LSS) is the most common diagnosis requiring spinal surgery in Sweden. The incidence seems to be increasing worldwide.” The researchers noted that in the thirteen-year period up to 1992, the American rate for surgery increased fivefold.
By virtue of the study being a data exercise, it is impossible for the team to state that nicotine is responsible for the observations, but they do include reference to prior studies in the introduction: “The influence of nicotine on disc metabolism and degeneration has been investigated in the literature. It involves both chronic vasoconstriction and inflammatory degeneration of the disc cartilaginous component. Exposure to nicotine is also believed to reduce the pain threshold of the central nervous system as it can act as a central pain-modulating agent and individuals with higher rates and intensity of spine-related pain may be predisposed to addiction to help mitigate their symptoms. These effects seem to be reversible to some extent if smoking ceases.”
Lead author Arkan Sayed-Noor said: “Smoking appears to be a risk factor for developing lower spine space narrowing that can lead to surgical treatment. Quitting smoking can reduce the risk.”
Unreported in the media or by Sayed-Noor in his conversation with journalists, the study actually mentions problems with linking nicotine to the need for surgery: “Heavy smoking is usually associated with a sedentary lifestyle that might cause a lower relative muscle mass, which further increases strain on the lumbar spine and predisposes the development and progression of LLS.” There is a link between aortic calcification and back pain, which is coupled with being overweight, having hypertension and getting older.
So, while it is fine for the team to conclude: “Tobacco smoking is associated with increasing the incidence of surgically treated LSS,” the evidence is not here in this paper to place nicotine into the dock. It would be interesting to see if long-term vapers demonstrate the same rates as smokers – or reflect the reduced risk of non-smokers, despite still using nicotine?