April 03, 2013

By Lorraine L. Janeczko

NEW YORK (Reuters Health) Apr 03 - Patients treated for axial or radicular pain related to a spinal disorder reported less pain and disability after they quit smoking, in a new study.

The strong association between pain and smoking cessation was reported by older and younger patients alike.

"This study found that patients who smoked suffered more from their spinal problems and that quitting smoking was associated with improved pain," said lead author Dr. Caleb Behrend from the University of Rochester in Rochester, New York, in an email to Reuters Health.

"If patients want to feel better and live longer, then smoking cessation is a good idea. The key point to stress to patients is that smoking is not only associated with increased mortality but there is growing evidence it may decrease their quality of life long before that," he added.

Smoking is a known risk factor for back pain and disc disease, whereas smoking cessation is associated with improved fusion rates from spinal procedures and improved patient reported pain and disability scores, the research team wrote in a poster presented March 22, 2013 at the annual meeting of the American Academy of Orthopaedic Surgeons in Chicago.

To study the effects of smoking cessation on pain, the team used a prospectively maintained database at two academic centers. They identified four groups of patients with axial or radicular pain related to a spinal disorder: never smokers (n=2,678), smokers who had quit prior to study entry (n=1,558), smokers who quit during study (n=259), and current smokers (n=932).

When patients were stratified by age (at least 55, n=2426, or younger, n=3001), 8.9% of the older group smoked, compared with 23.9% of younger patients. Proportions of former smokers were similar in the two groups, however: 25.1% in the older group, and 26.1% in the younger group.

The average length of follow-up was eight months (minimum, one month). At the outset, never smokers and prior smokers reported significantly less pain than current smokers and those who eventually quit during the follow-up period (p<0.001).

In all Visual Analog Scale (VAS) pain ratings obtained during the course of care, current smokers reported significantly higher mean pain (p<0.001) compared with patients who had never smoked and with those who had previously quit smoking. Patients who had quit smoking prior to the study reported significantly higher rates of mean worst pain (p=0.028) and average weekly pain (p=0.049) compared with patients who had never smoked.

Patients in both age groups who continued to smoke during treatment reported no clinically significant improvement in pain.

"Smoking is associated with decreased quality and quantity of life. Studies demonstrate that smoking cessation is associated with improved fusion rates, improved patient reported pain, reduced complication rates, reduced perioperative mortality, and improved long term survival," the authors wrote in their presentation.

Dr. Michael R. Marks, president of Norwalk Hospital Physicians & Surgeons and AAOS spokesperson, commented in an email to Reuters Health that these findings provide more evidence that stopping smoking leads to better orthopaedic health in the short term.

"Many people and physicians feel that they have been smoking for so long, it's not worth stopping now. This paper says otherwise. Every little bit helps and it's never too late," he noted.

The researchers were surprised by one finding. They had expected that older patients would not quit smoking at the same rate as younger patients and would not report improved pain. But older patients in their study were equally likely to quit smoking and to report that their pain had eased.

Looking ahead, Dr. Behrend said the underlying pathophysiology of the relationship between smoking and chronic pain needs further study.

Dr. Marks asked, "If a patient stops smoking but uses a nicotine patch will they still have the same beneficial effects? Are the positive effects due to improved vascular flow, less ingested carbon monoxide, or the lack of nicotine and the other active ingredients contained in cigarettes?"

In a related study presented at the same meeting, Dr. Mara L. Schenker and colleagues found in a meta-analysis that smoking was associated with increased nonunion for all fractures, open fractures, and tibia fractures, and that smokers tended to have longer mean healing times. (See Reuters Health story of Apr 2, 2013.)

In another related study, Dr. Bhaveen Kapadia and colleagues found that smokers had increased revision rates and other complications after total hip arthroplasty. (See Reuters Health story of Apr 1, 2013.)