Chlamydial LPS and high-sensitivity CRP levels in serum are associated with an elevated body mass index in patients with cardiovascular disease.
OBJECTIVE
Seropositivity for Chlamydia pneumoniae has been associated with an elevated body mass index (BMI). Our aim was to study if serum chlamydial lipopolysaccharide (cLPS), C. pneumoniae antibodies and high-sensitivity C-reactive protein (hsCRP) levels are associated with BMI.


METHODS
The study population consisted of 174 patients with symptomatic carotid stenosis, abdominal aortic aneurysm or occlusive aortic disease. Information on BMI, diabetes, smoking, hypercholesterolemia, and statin medication was available. Serum C. pneumoniae IgG and IgA antibodies, cLPS, hsCRP and total endotoxin activity (totLPS) were measured.


RESULTS
BMI correlated with cLPS (r = 0.197; P < 0.01) and with hsCRP (rho = 0.195; P < 0.01); in addition, there was a positive correlation between cLPS and hsCRP (rho = 0.499; P < 0.01). A trend of an increasing proportion of C. pneumoniae IgG positivity (titre > or = 64; P = 0.018) and higher serum cLPS (P = 0.01) and hsCRP (P = 0.01) concentrations was observed across the BMI groups (BMI < or = 24.9 kg/m(2), BMI = 25.0-29.9 kg/m(2), and BMI > or = 30.0 kg/m(2)). Among the three BMI groups, 24.6%, 38.8%, and 48.3% were C. pneumoniae IgG-positive and the median (IQR) cLPS concentrations (ng/ml) of the groups were: 92.6 (50.8-167.0), 128.9 (76.4-163.9), and 146.4 (105.8-175.8), respectively. The median (IQR) hsCRP (mg/l) concentrations of the groups were: 1.70 (0.70-3.05) 1.70 (0.80-5.20), and 3.40 (1.45-8.55), respectively. These associations remained statistically significant in a multivariate analysis.


CONCLUSIONS
Elevated serum cLPS levels were associated with an elevated BMI. This is a novel finding and it strengthens the link between chlamydial infection and obesity. A lack of association between totLPS and BMI suggests that the association between infection and an elevated BMI may be specific to certain pathogens.
Lajunen
Taina
T
Respiratory Infection Unit, National Public Health Institute, Oulu, Finland. taina.lajunen@ktl.fi
Vikatmaa
Pirkka
P
Bloigu
Aini
A
Ikonen
Tuija
T
Lepäntalo
Mauri
M
Pussinen
Pirkko J
PJ
Saikku
Pekka
P
Leinonen
Maija
M
D000368:Aged; D000907:Antibodies, Bacterial / Q000097:blood / Q000276:immunology; D015992:Body Mass Index; D002097:C-Reactive Protein / Q000378:metabolism*; D002318:Cardiovascular Diseases / Q000097:blood / Q000209:etiology / Q000382:microbiology* / Q000503:physiopathology*; D023521:Chlamydophila Infections / Q000097:blood / Q000150:complications; D016993:Chlamydophila pneumoniae / Q000276:immunology / Q000378:metabolism*; D005260:Female; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood / Q000276:immunology; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D008070:Lipopolysaccharides / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000209:etiology
D000907:Antibodies, Bacterial; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D008070:Lipopolysaccharides; D002097:C-Reactive Protein