St Richard's Hospital Vascular Unit                         Royal West Sussex NHS Trust

• Smoking

Smoking is one of the two most potent risk factors for the development of atherosclerotic arterial disease (diabetes being the other). It is estimated that current smokers are 16 times more likely to develop  atherosclerosis. Even ex-smokers will have a 7 times increased risk. The damaging effect of smoking on arteries is multifactorial. Smoking is known to increase the blood levels of carbon monoxide and to increase the blood thickness. Carbon monoxide can damage the delicate thin lining of the blood vessels (the endothelium) making it easier to form atherosclerosis. The increased thickness of the blood makes it more difficult for it to flow in small or narrowed arteries.

The danger of smoking is that it can affect the medium and large size arteries anywhere in the body. This can lead to  coronary heart disease, leg arterial disease, brain arterial disease, high blood pressure, etc. Smoking is also known to reduce  the effectiveness of any treatment received by patents suffering from these conditions. Stopping smoking improves the blood quality and can reverse some of the symptoms associated with such diseases.

•  Diabetes 

Diabetes develops when the body loses its ability to control blood sugar levels.  Untreated or poorly treated diabetes can adversely affect almost every system in the body. Patients with diabetes are three to five times more likely to develop peripheral arterial disease. The tendency of diabetes to affect smaller blood vessels leads to a type of arterial disease that is particularly difficult to treat. Typically, diabetic peripheral arterial disease manifests as an infection of the toes and feet. This infection is quite aggressive and may not respond to simple antibiotic treatment. Whilst controlling diabetes is very important, normalising blood sugar levels does not appear to reduce the risk of developing peripheral arterial disease.

• High blood pressure

High blood pressure or "hypertension" accelerates the process of atherosclerosis which in turn leads to further rise in blood pressure. The high blood pressure leads to damage to the endothelium and helps in initiating the process of arterial wall thickening. Controlling blood pressure has been shown to reduce the incidence of ischaemic heart disease and strokes.

• Cholesterol and other lipids

Lipids are the forms of fat found in the blood and other tissues. Cholesterol, which exists in two forms, is an important member of the lipid family. High density lipoprotein "HDL" cholesterol has a beneficial effect in maintaining healthy blood vessels. On the contrary, low density lipoprotein "LDL" cholesterol plays a major role in the development of atherosclerosis.  When other risk factors cause damage to the endothelial lining of the arteries, cholesterol precipitates on the deeper layers of the arterial wall and initiates the process of atherosclerotic plaque formation.  Lowering cholesterol in high risk patients (even in those with normal cholesterol levels) has been found to significantly reduce the risk of vascular events especially when this is coupled with a small dose of Aspirin.   

• Other risk factors

There is a group of other factors which are known to participate in the development of atherosclerotic arterial disease. Aging is generally associated with increased risk of may diseases particularly those of the arteries. Lack of exercise and obesity are also risk factors for arterial disease. Some vitamin deficiency together with high levels of chemicals such as "homocysteine" and "lipoprotein a" have also been linked to atherosclerosis.

An arterial "plaque". Calcium and cholesterol deposition into the inner arterial lining form a "cast" of the artery. In this case, the cast was surgically removed intact. 

Severe foot infection in a patient with diabetes.