Last week it was cancer, this
week it's heart disease

Now it turns out that H pylori could be the culprit
behind heart problems too

By Brian Hoyle

Could the pesky ulcer-causing Helicobacter pylori bacterium be tied to heart problems? Two recent studies said yes. Research published in the January 15 issue of the American Journal of Cardiology (AJC) showed that treatment of H pylori infections in ulcer patients increased the level of 'good,' artery-clearing cholesterol. Dr Hubert Scharnagl, of the University of Graz in Austria, and colleagues monitored 87 patients who were placed on anti-H pylori drugs as a treatment for intestinal ulcers to see what effect the elimination of the bacterial infections had on their levels of lipids and apolipoproteins. The team measured total cholesterol, triglycerides, high-density and low-density cholesterol (HDL and LDL), lipoprotein (a) and apolipoproteins AI, AII and B at the beginning of treatment and one year later.

Higher levels of HDL, dubbed good cholesterol, help remove artery-clogging compounds like LDL, which has earned the moniker of 'bad' cholesterol. A decreasing ratio of HDL to LDL can be a warning of artery congestion and impending heart trouble.

The AJC study reported that the elimination of the H pylori infections was accompanied by increases of almost 25% in the levels of HDL and triglycerides and 16% for apolipoprotein B while LDL levels did not increase at all.

An especially welcome finding was that the good to bad cholesterol ratio increased almost 12%. The increase in HDL was "at least as strong" as that seen in patients treated with the well-known bad cholesterol-busting statins, according to the researchers.

Further work is needed to figure out the relationship between H pylori infections and cholesterol.

In the second study, published in the European Heart Journal, the presence of H pylori strains harbouring a particular gene was associated with atherosclerotic stroke. Researchers isolated strains of H pylori that produce Cytotoxin-associated gene A (CagA) significantly more often from patients who suffered strokes due to atherosclerosis.

In atherosclerosis, arteries progressively deteriorate due to the formation of plaques made up of dead cells, fat and cholesterol crystals. The plaques may dislodge and travel to the heart, precipitating a stroke.

Senior investigator Dr Antonio Gasbarrini of the Catholic University of the Sacred Heart, Brescia, Italy and colleagues studied 105 atherosclerotic stroke patients and 130 other patients without heart disease.

The presence of CagA-positive strains of H pylori was significantly greater in the stroke patients than in the controls (expressed as an adjusted odds ratio of 2.9). Further, detection of antibodies to the CagA protein was the only factor that was "independently associated" with the plaques that can dislodge from the carotid artery and cause the stroke (adjusted odds ratio 8.42).

Until now, the nature of the H pylori-stroke link was unclear.

"Confirming and defining the CagA-positive H pylori infection as a novel risk factor for atherosclerotic stroke might open new perspectives for stroke prevention based on specific antibiotic treatment," said Dr Gasbarrini.