Pulmonary Hypertension and Smoking

Smoking has been proven to be harmful to health on a variety of levels. Tobacco use is currently the single largest preventable cause of death and disease in the U.S., according to the Centers for Disease Control and Prevention (CDC). In 2013, CDC statistics revealed that 17.8% of American adults were smokers, equivalent to 42.1 million people. However, this habit kills 480,000 people every year in the U.S. alone, over 41,000 of which are related to secondhand smoke exposure.

Smoking is estimated to increase the risk for coronary heart disease and stroke by 2 to 4 times, and of lung cancer by more than 25 times. Numerous other conditions are related to smoking, including pulmonary hypertension (PH), a rare but severe disease characterized by high blood pressure in the lungs. The pulmonary arteries of patients who have PH become narrowed and thickened, making it difficult for the heart to properly pump the blood into the lungs.

How smoking contributes to PH

“Cigarette smoke is known to be associated with pulmonary hypertension in humans and in animal models. Although the etiology of pulmonary hypertension in smokers is not understood, recent work has suggested a role for inducible nitric oxide synthase (iNOS) in inducing oxidative stress,” as explained in the study “Pulmonary hypertension and vascular oxidative damage in cigarette smoke exposed eNOS(-/-) mice and human smokers,” authored by Wright JL, Zhou S, Churg A, from the Department of Pathology, of the University of British Columbia, in Vancouver, Canada.

Cigarette smoking significantly increases PH mainly due to the reactive nitrogen species and consequent oxidative vascular damages, as concluded by the authors. In addition, smoking is the greatest contributor to the development of chronic obstructive pulmonary disease (COPD), chronic bronchitis and emphysema, which are diseases correlated with secondary pulmonary hypertension. Therefore, smokers who develop PH are likely to also have other lung conditions.

Impact of continued smoking on PH patients

There is currently no cure for PH, but there are treatments that help ease the symptoms of the disease and increase life expectancy. Medications and therapies are, however, not enough, and lifestyle alterations are also required for patients. Quitting smoking is one of the most important changes PH person can make for their health. When patients are not able to give up smoking, the progression of the disease tends to be faster, while quality of life is decreased.

Patients with PH who continue to smoke are more likely to have exacerbated symptoms, including shortness of breath (dyspnea), fatigue, dizziness or fainting spells (syncope), pain or pressure in the chest, swelling (edema) in the ankles, legs and abdomen (ascites), irregular heartbeat, and difficulties exercising or even performing daily activities. Quitting smoking, however, is not easy; patients should consult their physicians to design a smoking cessation plan or to prescribe medication for that purpose.