Gene Links Gum Disease And Heart Attack Risk

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Main Category: Dentistry
Also Included In: Heart Disease;  Genetics;  Seniors / Aging
Article Date: 26 May 2009 - 2:00 PDT

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Scientists in Germany have discovered a gene that links the gum disease periodontitis and increased risk of coronorary heart disease (CHD) and although they don't yet fully understand the underlying mechanism of the link, they urged dentists to make sure they diagnose and treat cases of periodontitis as early as possible to mimimize the risk of heart disease.

The discovery, was the work of Dr Arne Schaefer, of the Institute for Clinical Molecular Biology at the University of Kiel, and colleagues. Schaefer presented their findings to the annual conference of the European Society of Human Genetics in Vienna on Monday 25 May.

CHD is the leading cause of human deaths worldwide, and periodontitis, a type of gum disease that results in loss of connective tissue and the bone that supports the teeth, is the major cause of tooth loss in adults over 40 years old.

Periodontitis is very common and affects over 90 per cent of people over 60 years old.

Scientists already knew that periodontitis and CHD were linked somehow and that it was most likely genetic, but until this discovery they weren't certain.

Schaefer and colleagues found a gene on chromosome 9 whose variant is shared between gum and heart disease.

A genetic locus on chromosome 9p21.3 was already known to be associated with myocardial infarction (heart attack), so they decided to study it in two groups of patients: 151 patients with aggressive early stage periodontitis, and 1,097 patients with CHD who had already had a heart attack.

"The genetic variation associated with the clinical pictures of both diseases was identical," said Schaefer.

The researchers confirmed the link by studying two other groups: one of 1,100 CHD patients and another of 180 periodontitis patients.

"We found that the genetic risk variant is located in a genetic region that codes for an antisense DNA called ANRIL", said Schaefer, explaining that it was also "identical for both diseases."

When genes make proteins they first unravel their two strands of DNA double helix. On strand makes messenger RNA (mRNA), which goes on to make the protein and the other reverse strand, called "antisense" DNA, often carries antisense RNA that complements the mRNA and can bind to it and inhibit its ability to express protein.

Schaefer said they now want to find out more about how this RNA works and the pathway it uses in healthy and diseased gums.

"In the meantime, because of its association with CHD, we think that periodontitis should be taken very seriously by dentists and diagnosed and treated as early as possible", he cautioned.

Men and more likely to suffer from CHD and periodontitis and the two diseases share similar risk factors such as smoking, diabetes and obesity.

An imbalanced immune reaction and chronic inflammation are also features of both diseases, and scientists have also discovered for example that the presence of specific bacteria in periodontal pockets might explain the relationship between periodontal disease and acute coronary syndrome.

This study confirms the genetic link hinted at by these factors, said Shaefer, who urged:

"Patients with periodontitis should try to reduce their risk factors and take preventive measures at an early stage."

"We hope that our findings will make it easier to diagnose the disease at an early stage, and that in future a greater insight into the specific pathophsyiology might open the way to effective treatment before the disease can take hold," he added.

In January 2007, US scientists also reported a link between pancreatic cancer and gum disease, and last month scientists in Japan suggested that periodontal disease could act as a risk factor for reactivating latent HIV-1 in affected individuals.

Sources: European Society of Human Genetics, MNT archives.

Written by: Catharine Paddock, PhD
Copyright: Medical News Today
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