Nicotine Withdrawal Woes Shown To Be Similar To Inflammatory Response

Dr. Elizabeth Corwin, assistant professor in the school of nursing and the Intercollege Physiology Program, says, "Our research shows that nicotine withdrawal is a significant physical as well as psychological stressor that impacts multiple systems of the body, including the immune system. If we can relieve some negative symptoms – including depression – by reducing the inflammatory response, we may be able to increase the likelihood that heavy or moderate smokers can successfully quit."

The study, which was conducted by Corwin and Dr. Laura Klein, assistant professor of biobehavioral health, was presented (today) Feb. 21, by Klein in a poster at the meeting of the Society for Research in Nicotine and Tobacco in Savannah, Georgia. The poster is titled, "Sickness Behavior and Cytokine Responses in Subjects During Withdrawal from Nicotine."

Klein explains that smokers often fail multiple attempts to quit, in part, because of the unpleasant symptoms that accompany nicotine withdrawal, including depression, fatigue, muscle aches and appetite changes. Similar unpleasant symptoms accompany acute and chronic illness and these symptoms are known to result from elevated levels of cytokines, which are produced by white blood cells in response to inflammation. The two Penn State researchers decided to see if cytokines could also be linked to the same symptoms in smokers who stop smoking.

Blood samples from 20 heavy or moderate smokers, ages 18 to 35, were taken while they were smoking freely and after they had stopped smoking for 24 hours. Blood samples were also taken from 22 non-smokers for comparison. The same groups of smokers and non-smokers also completed questionnaires to gauge their fatigue, depression, muscle aches and appetite.

Analysis of the symptom self-reports showed that depression, muscle aches and appetite all increased in smokers during nicotine withdrawal. Although fatigue did not increase significantly with nicotine withdrawal, smoker's fatigue scores were already higher at the start of the study when compared to non-smokers.

Analysis of the blood samples showed that the levels of two cytokines, interleukin-1 beta (IL-1b) and interleukin-6 (IL-6), along with fatigue, in smokers predicted depression on nicotine withdrawal. Changes in the production of IL-6 were associated with muscle aches and increased appetite when smoking was stopped. There were no differences in men's and women's responses.

Corwin says, "The results support the hypothesis that smokers who stop smoking may experience depression, fatigue, muscle aches and appetite changes for similar biochemical reasons that individuals who have acute or chronic disease do. The same therapies – anti-inflammatory medications – may therefore help alleviate these symptoms."

Further studies are needed to find out which particular anti-inflammatory drugs or specific pro-inflammatory blocking agents might best reduce the unpleasant symptoms of nicotine withdrawal and support smokers while they quit. Corwin and Klein are planning such studies.

The current study was supported by a grant from a Penn State interdisciplinary seed grant awarded by the University's Life Science Consortium.