Combined seropositivity for H. pylori and C. pneumoniae is associated with age, obesity and social factors.
BACKGROUND
Manifestations of cardiovascular disease (CVD) have been associated with chronic infection by Helicobacter pylori and Chlamydia pneumoniae both in cross-sectional and in prospective follow-up cohort studies. This association may be partly due to an increase in metabolic risk factors for CVD, secondary to low-grade inflammation caused by infections.


OBJECTIVE
To investigate for subjects classified according to serology titres for infection with C. pneumoniae and H. pylori associations between seropositivity and the degree of obesity and fasting insulin levels, as well as social factors.


METHODS
Using methods based on those in earlier investigations of hypertensive patients in the Dalby primary-health-care district, southern Sweden, we investigated frozen samples from serum of 310 middle-aged treated hypertensives and 288 age-matched and sex-matched normotensive controls from a defined population. The baseline examination included the measurement of weight, height and blood pressure as a mean of two office readings with the subject supine. The body mass index (BMI) was calculated as kg/m2. Fasting blood samples were drawn for measurements of levels of serum lipids, blood glucose, plasma insulin and serum lipids, including total cholesterol and triglycerides. The serology titres for H. pylori were determined by an enzyme-linked immunosorbent assay. The titres for C. pneumoniae were determined by a micro-immunofluorescence method. Self-reported factors concerning social and lifestyle backgrounds were recorded.


RESULTS
The group (n = 245) of subjects with combined positive serology for H. pylori and C. pneumoniae differed from the group without any positive serology (n = 57) in age (61.6 versus 57.4 years, P < 0.05) and BMI (27.3 versus 25.8 kg/m2, P < 0.05). The seropositive group also differed in terms of fasting levels of insulin (12.7 versus 11.6 pmol/l, P < 0.05), but this difference did not remain significant after adjustment for age and BMI. We detected no intergroup difference in blood pressure and levels of glucose and lipids. Members of the group with combined seropositivity reported having a lower social-class position (educational level) than that of members of the seronegative group.


CONCLUSIONS
Subjects with combined positive serology for H. pylori and C. pneumoniae are characterized by greater age, lower social class and higher BMI, as well as higher fasting levels of insulin than those of seronegative subjects. Obesity might be a marker not only for lower social class but also for greater than normal susceptibility to such infections.
Ekesbo
R
R
Primary Health Care Centre, Dalby, Sweden. ekesbo.mevrick@swipnet.se
Nilsson
P M
PM
Lindholm
L H
LH
Persson
K
K
Wadström
T
T
D000367:Age Factors; D000368:Aged; D000907:Antibodies, Bacterial / Q000032:analysis*; D015992:Body Mass Index; D002318:Cardiovascular Diseases / Q000209:etiology*; D023521:Chlamydophila Infections / Q000150:complications*; D016993:Chlamydophila pneumoniae / Q000276:immunology*; D003430:Cross-Sectional Studies; D003627:Data Interpretation, Statistical; D004493:Education; D005260:Female; D005455:Fluorescent Antibody Technique; D016481:Helicobacter Infections / Q000150:complications*; D016480:Helicobacter pylori / Q000276:immunology*; D006801:Humans; D006973:Hypertension / Q000150:complications*; D015151:Immunoblotting; D007124:Immunoenzyme Techniques; D007074:Immunoglobulin G / Q000032:analysis; D007328:Insulin / Q000097:blood; D008055:Lipids / Q000097:blood; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications*; D010865:Pilot Projects; D012044:Regression Analysis; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects; D012923:Social Class
D000907:Antibodies, Bacterial; D007074:Immunoglobulin G; D007328:Insulin; D008055:Lipids