Gum disease and heart disease in the PRIME study
In recent years there has been increasing interest in a possible association between periodontal (gum) disease and cardiovascular disease. People are keen to know whether such an association exists and the possible implications for them. Gum disease is one of the commonest conditions and so it may be of considerable significance even if it is only associated with a small increase in the risk of cardiovascular disease such as heart disease or stroke.
Gum disease is caused by the bacteria that build up on the teeth (dental plaque). As it progresses the gum comes away from the teeth leaving spaces (pockets) into which the bacteria spread causing inflammation and infection. During normal activities such as eating and toothbrushing bacteria from these pockets can get into the blood stream and could contribute to changes which take place in the coronary arteries resulting in heart attacks.
The PRIME study is currently investigating whether gum disease is associated with an increase in new coronary heart disease events. We examined the gum tissues of 1400 men, aged between 60 and 70 years, taking part in the PRIME study between 2001 and 2004. The men also had a physical and medical examination and provided information on their medical history and behaviour. They are being followed-up to identify those who develop heart disease.
Evidence that gum disease could be a causative factor for heart disease can only be produced by prospective studies such as the PRIME study and it remains the only prospective cohort study of this possible link in the United Kingdom at this time. In the first prospective outcome study we analysed the association between periodontitis and death from any cause in the men who had a dental examination. Those with the most severe gum disease were at an increased risk of death compared to those with low levels of gum disease, after 9 years of follow-up.
By their nature such studies are long running and it will be some years before we have all the results of the PRIME dental study into possible links between periodontal disease and cardiovascular diseases.