Risk factors for coronary heart disease and infection with Helicobacter pylori: meta-analysis of 18 studies.

To find out if chronic infection with is correlated with risk factors for coronary heart disease. Meta-analysis of 18 epidemiological studies, involving a total of 10 000 patients, that measured serum antibody titres to and risk factors for coronary heart disease. Any study published in any language before 1998 was eligible for inclusion. Only small absolute differences in body mass index, blood pressure, or haematological risk factors were found between subjects who were seropositive and those who were seronegative. In those who were seropositive body mass index was slightly higher (0.37, SE 0.09) and concentrations of high density lipoprotein cholesterol were slightly lower (0.032 mmol/l, 0.008). None of the other differences were highly significant. Previous claims of substantial correlations between seropositivity and certain vascular risk factors were largely or wholly due to chance or the preferential publication of positive results, or both.