(Reuters Health) - - Smoking increases the risk of lower back pain that needs to be fixed by spinal surgery, a Swedish study suggests.

A man smokes in Budapest, Hungary, May 12, 2017. REUTERS/Laszlo Balogh

Researchers focused on a common cause of lower back pain known as lumbar spinal stenosis, which occurs when the spinal canal narrows, putting pressure on the spinal cord and nerves. The condition often develops as people age, but nicotine’s constriction of blood flow and promotion of inflammation are believed to contribute to the process, the study authors write.

The researchers examined data on 331,941 construction workers who were part of a nationwide occupational health registry in Sweden. Workers were followed for an average of more than three decades, starting when they were typically in their 30s, and 1,623 of them eventually had surgery for lumbar spinal stenosis.

Compared to people who never smoked, heavy smokers who went through at least 15 cigarettes a day were 46 percent more likely to have this spinal surgery, the study found. For moderate smokers who had up to 14 cigarettes a day, the increased risk was 31 percent, while ex-smokers had 13 percent higher odds of surgery.

“Smoking appears to be a risk factor for developing lower spine space narrowing that can lead to surgical treatment,” said senior study author Dr. Arkan Sayed-Noor, a researcher at Umea University.

“Quitting smoking can reduce the risk,” Sayed-Noor said by email.

While some previous research has linked smoking to worse outcomes from spinal surgery, the current study offers fresh evidence that it can also increase the odds that back pain will require surgery, Sayed-Noor added.

Overall, 44 percent of the study participants were non-smokers. Another 16 percent were former smokers, while 26 percent were moderate smokers and 14 percent were heavy smokers.

The connection between smoking and spinal surgery persisted even after researchers accounted for other factors that can increase the odds of lower back pain such as aging and obesity.

Smoking damages the spine in several ways, researchers note in The Spine Journal. Nicotine can damage spinal tissue, weaken bones and make back pain worse.

Heavy smoking is also often accompanied by a sedentary lifestyle that may lead to muscle weakness and increase strain on the lower back.

One limitation of the study is that researchers lacked data on exercise habits, the authors note. Most of the construction workers in the study were men, and the results might be different for women.

Still, the findings add to evidence linking cigarettes to disc damage and back pain, said Dr. Jean Wong, a researcher at the University of Toronto who wasn’t involved in the study.

“There are multiple short and long-term health reasons for smokers to quit, and by quitting smoking, smokers can reduce their risk of back pain due to disc degeneration and spinal stenosis - which can be a debilitating problem in smokers,” Wong said by email. “Although it may take multiple attempts, quitting smoking is the best thing a smoker can do to minimize the risk of spinal stenosis and other health problems.”

SOURCE: bit.ly/2CXnjDL The Spine Journal, online December 12, 2017.