Tobacco Use Issue, Nicotine Addiction

In previous columns on fractures and osteoporosis, I discussed the negative effects of smoking as it pertains to the musculoskeletal system. Smoking interferes with fracture healing, wound healing and accelerates osteoporosis development. In today’s column, I will take a closer look at tobacco. Ten million cigarettes are sold per minute in the world every day. In the U.S., tobacco is responsible for one in every five deaths. It is calculated that the annual cost of health-related expenses because of tobacco approaches $193 billion in the U.S. alone. Smoking releases not only hazardous gases, such as carbon monoxide, but also chemicals such as nicotine into the bloodstream. These, acting alone or in combination, can produce a number of unwanted side effects over a long period of time, such as changes to cellular DNA, which in turn causes mutations of normal cells into cancer cells. Nicotine causes vascular constriction, or narrowing of the blood vessels. This is an important concept, because less blood flow means less oxygen and nutrition going to the area of the fracture site and soft tissue trauma. Decreasing the amount of blood flow also means that there are less lymphocytes delivered to the fracture site. Lymphocytes are important in preventing an infection. We have read many times that smoking causes coronary artery disease, or heart attacks and narrowing of the carotid arteries, which causes strokes. Nicotine not only narrows these arteries with an immediate vasoconstriction, or narrowing effect, but also causes platelet aggregation and gradual plaque buildup over time in these arteries. We are also familiar with people acquiring chronic obstructive pulmonary disease and emphysema from smoking. This is due to the hazardous gases damaging the cells lining the alveoli of the lungs. Smoking also accelerates osteoporosis. First, it reduces the number of osteoblasts present in bone. Osteoblasts are those cells that are responsible for forming new bone growth. Secondly, nicotine will decrease the level of estrogen. This, as we know, has a protective effect against bone reabsorption by osteoclasts. Controlled studies comparing smokers to nonsmokers in comparing rates of healing and infection obviously are hard to develop. The literature, however, does give us some insight into several studies that seem to be well controlled. One study demonstrated that smokers were twice as likely to develop a postoperative infection as a nonsmoker. Obviously, this infection could not only be infection in the wound or bone, but also an infection such as pneumonia. Another study showed that smokers are 3 1/2 times more likely to develop a long-term infection in the area of the fracture. Finally, one study showed that smokers are 37 percent more likely not to heal a bone if they smoke versus a nonsmoker.