Peripheral vascular disease

Smoking affects your blood vessels

There are over 4000 different types of chemicals in cigarette smoke.¹ Once inhaled into the lungs, many of these chemicals pass through your lung walls, into your bloodstream and are carried around your body.^{1, 2}

Chemicals from smoke affect your blood, making it thicker, stickier and more likely to form clots. They cause fatty material to build up on your blood vessel walls faster. Over time, this slowly narrows and blocks your blood vessels making it difficult for your blood to circulate. This is the main way that smoking causes peripheral vascular disease (PVD).³

What is PVD?

Peripheral vascular disease (PVD) refers to diseases of the arteries (the large blood vessels), except for those in the heart and brain.⁴ It also may be called peripheral arterial disease (PAD).^3-5 It occurs when the arteries that carry blood to your legs or arms become partially or totally blocked by the build up of fatty material on your artery walls.^{3, 6} 

PVD mainly affects blood circulation to the legs and feet.^{4, 6} About half of all people with PVD do not have any symptoms (asymptomatic PVD).⁵ For people who have PVD with symptoms, the most common is pain in the legs, particularly the calves, when walking. The pain usually goes away within several minutes after stopping exercise.³

Other symptoms may include:

• numbness, weakness or a feeling of heaviness in the legs with no pain⁶
• hair loss on your feet and legs⁷
• poor nail growth (brittle toenails)⁷
• cool patches of skin on your feet or legs⁶
• a change in the colour of your legs^{6, 7}
• a weak pulse in your legs.⁷

Symptoms of more advanced PVD include:

• sores or ulcers on your toes and feet that do not heal properly^5-7
• burning or aching feet or toes while resting, especially when lying flat (rest pain).^{5, 6}

These symptoms can be distressing as they can involve constant pain.⁸

In severe cases of PVD, there is not enough blood supply to the edge of the feet or toes. The foot becomes purplish, cold and painful. Wounds on the feet heal poorly and ulcers form easily. Feet in this state can progress to gangrene, which is when tissue becomes blackened and dead. It may become necessary for a surgeon to cut off affected toes, feet or legs as a last resort to relieve pain (amputation).⁸ Only a very small percentage of people with PVD end up needing amputation, but continuing to smoke is a major risk factor for the loss of feet and limbs.⁹

A major form of PVD affects the main artery leading from the heart (the aorta).  When the aorta becomes abnormally wider or balloons outwards, this is called an aortic aneurysm.  Aortic aneurysms can be life-threatening if they split open and bleed.⁴ 

The lower part of the aorta is called the abdominal aorta, and supplies blood to your abdomen, pelvis and legs.  Abdominal aortic aneurysms are most often the result of the build up of fatty material on the artery walls.  Smoking is one of the few avoidable causes of this potentially fatal disease.³

How common is PVD?

There are around 2000 new cases of aortic aneurysm and around 850 new cases of other types of PVD each year in Victoria.  In 2001, almost 300 Victorians died from aortic aneurysm and around 190 died from other types of PVD^.10   Most cases of aortic aneurysm are successfully treated with surgery.  However, over 5,000 Victorians with PVD other than aortic aneurysm continue to live with the disease.¹⁰  

People who have PVD often die from heart disease or stroke rather than PVD, as these diseases are caused by similar processes.^{4, 5, 9} PVD most often occurs in people aged over 40 years old.⁷

Smoking and PVD

Smoking is the number one risk factor for PVD.⁶ Over 80% of people with PVD affecting the lower limbs are smokers or ex-smokers.⁹ Smokers are two and a half times more likely to develop PVD than someone who has never smoked.¹¹ Smoking causes 40% of PVD in men and 34% of PVD in women in Australia (includes aortic aneurysm and other peripheral vascular disease).¹²

Smoking results in symptoms of PVD developing earlier in life.⁹ The severity of PVD increases with the number of cigarettes smoked.⁹ People who smoke are likely to worsen their symptoms of PVD, and they increase their risk for amputation.⁹ Smoking also reduces the success of treatments for PVD.⁹ 

The processes that lead to PVD start early. Every puff of cigarette smoke contains huge amounts of oxidants. These chemicals play an important role in the build up of fatty deposits in arteries, as well as in causing cancer and lung disease.³ Research shows that even young smokers in their teens and early twenties have more fatty deposits in the main artery of their heart than non-smokers of the same age.³

Other risk factors for PVD include diabetes, high blood pressure, and high cholesterol levels.^{6, 7} If you have more than one of these risk factors, your risk of PVD increases. Stopping smoking may also help control some of these other risk factors as smoking worsens cholesterol levels and interferes with the management of diabetes.^{13, 14} Smokers are also more likely to develop Type 2 diabetes.¹⁴

Stopping smoking reduces your risk

Quitting smoking will reduce your risk of developing PVD, but ex-smokers are still more likely to develop PVD than people who have never smoked.^{11, 13} However, the longer you have quit, the lower your risk of developing symptoms of PVD.¹⁵

For people who develop symptoms of PVD, quitting slows down the progress of the disease.^{7, 13} Compared to smokers, people who quit have less severe pain when walking and are less likely to develop pain at rest.^{3, 5, 7, 13} They live longer, respond better to treatment, and are less likely to require amputation.^{5, 7, 13}

It is necessary to quit completely as smoking even one or two cigarettes a day immediately affects your circulation and can affect treatment.^{3, 6}

Treatment for advanced PVD may include surgery to restore blood flow to the arteries.⁸ Stopping smoking at least eight weeks before surgery improves wound healing and reduces the risks for serious complications.^{16, 17}

Stopping smoking has both immediate and long-term health benefits

If you quit before developing PVD:

• Within one day the level of carbon monoxide in your blood drops dramatically. You have more oxygen in your bloodstream.¹³
• After a few weeks, signs of damage by oxidants in cigarette smoke have almost stopped completely.³
• After eight weeks your blood is less thick and sticky, and your blood flow will improve.^{13, 18} Your body is able to heal wounds better.¹⁶
• After 16 weeks your level of good cholesterol has improved.³ This helps slow down the build up of fatty deposits on your artery walls.¹³
• After 20 years your risk of developing symptoms of PVD, such as pain when walking, are greatly reduced compared to a continuing smoker.^{15, 19}

References

1. United States. Department of Health and Human Services. Reducing the health consequences of smoking : 25 years of progress : a report of the Surgeon General. Rockville, Md.: U.S. Dept. of Health and Human Services Public Health Service Centers for Disease Control Center for Chronic Disease Prevention and Health Promotion Office of Smoking and Health; 1989.
2. Shopland DR, National Cancer Institute (U.S.). Smoking and Tobacco Control Program. The FTC cigarette test method for determining tar, nicotine, and carbon monoxide yields of U.S. cigarettes. Bethesda, Md.: U.S. Dept. of Health and Human Services Public Health Service National Institutes of Health; 1996.
3. United States. Department of Health and Human Services. The health consequences of smoking: a report of the Surgeon General. Atlanta, GA: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Center for Chronic Disease Prevention and Health Promotion, Office on Smoking and Health; 2004.
4. Australian Institute of Health and Welfare. Heart, stroke and vascular diseases : Australian facts 2004. Canberra: Australian Institute of Health and Welfare and National Heart Foundation of Australia; 2004.
5. Hankey GJ, Norman PE, Eikelboom JW. Medical treatment of peripheral arterial disease. JAMA 2006;295(5):547-53.
6. Stevens LM, Lymn C, Glass RM. JAMA patient page. Peripheral arterial disease. JAMA 2006;295(5):584.
7. Gey DC, Lesho EP, Manngold J. Management of peripheral arterial disease. American Family Physician 2004;69(3):525-32.
8. Sorensen L, Wu T, Constantino M, Yue DK. Diabetic foot disease: an interactive guide. Peripheral vascular disease. Available at: http://www.diabetes.usyd.edu.au/foot/Pvdx1.html. Accessed 04 April 2006.
9. Norman PE, Eikelboom JW, Hankey GJ. Peripheral arterial disease: prognostic significance and prevention of atherothrombotic complications. Medical Journal of Australia 2004;181(3):150-4.
10. Victorian Burden of Disease Study : mortality and morbidity 2001. Melbourne, Victoria: Public Health Group. Department of Human Services; 2005.
11. English D, Holman CDAJ, Milne E, Winter MG, Hulse GK, Codde JP, et al. The quantification of drug caused morbidity and mortality in Australia, 1995 edition : Part 2. Canberra: Commonwealth Department of Human Services and Health; 1995.
12. Ridolfo B, Stevenson C. The quantification of drug-caused mortality and morbidity in Australia, 1998. Canberra: Australian Institute of Health and Welfare; 2001.
13. United States. Department of Health and Human Services. The health benefits of smoking cessation: a report of the Surgeon General. Rockville. Maryland: United States, Public Health Service, Office on Smoking and Health; 1990.
14. Eliasson B. Cigarette smoking and diabetes. Progress in cardiovascular diseases 2003;45(5):405-13.
15. Jensen SA, Vatten LJ, Nilsen TI, Romundstad PR, Myhre HO. The association between smoking and the prevalence of intermittent claudication. Vascular Medicine 2005;10(4):257-63.
16. Moller AM, Villebro N, Pedersen T, Tonnesen H. Effect of preoperative smoking intervention on postoperative complications: a randomised clinical trial. Lancet 2002;359(9301):114-7.
17. Rodrigo C. The effects of cigarette smoking on anesthesia. Anesthesia Progress 2000;47(4):143-50.
18. Shopland DR, United States. Office on Smoking and Health., United States. Dept. of Health and Human Services., United States. Public Health Service. Office of the Surgeon General. The health consequences of smoking : cardiovascular disease : a report of the Surgeon General. Rockville, Md.: U.S. Dept. of Health and Human Services Public Health Service Office on Smoking and Health ; Washington D.C.; 1983.
19. Cui R, Iso H, Yamagishi K, Tanigawa T, Imano H, Ohira T, et al. Relationship of smoking and smoking cessation with ankle-to-arm blood pressure index in elderly Japanese men. European journal of cardiovascular prevention and rehabilitation 2006;13(2):243-248.