C reactive protein and its relation to cardiovascular risk factors: a population based cross sectional study

Abstract

Objective: To test the hypothesis that minor chronic insults such as smoking, chronic bronchitis, and two persistent bacterial infections may be associated with increases in C reactive protein concentration within the normal range and that variations in the C reactive protein concentration in turn may be associated with levels of cardiovascular risk factors and chronic coronary heart disease.

Design: Population based cross sectional study.

Setting: General practices in Merton, Sutton, and Wandsworth.

Subjects: A random sample of 388 men aged 50-69 years from general practice registers. 612 men were invited to attend and 413 attended, of whom 25 non-white men were excluded. The first 303 of the remaining 388 men had full risk factor profiles determined.

Interventions: Measurements of serum C reactive protein concentrations by in house enzyme linked immunosorbent assay (ELISA); other determinations by standard methods. Coronary heart disease was sought by the Rose angina questionnaire and Minnesota coded electrocardiograms.

Main outcome measures: Serum C reactive protein concentrations, cardiovascular risk factor levels, and the presence of coronary heart disease.

Results: Increasing age, smoking, symptoms of chronic bronchitis, Helicobacter pylori and Chlamydia pneumoniae infections, and body mass index were all associated with raised concentrations of C reactive protein. C Reactive protein concentration was associated with raised serum fibrinogen, sialic acid, total cholesterol, triglyceride, glucose, and apolipoprotein B values. C Reactive protein concentration was negatively associated with high density lipoprotein cholesterol concentration. There was a weaker positive relation with low density lipoprotein cholesterol concentration and no relation with apolipoprotein A I value. C Reactive protein concentration was also strongly associated with coronary heart disease.

Conclusion: The body's response to inflammation may play an important part in influencing the progression of atherosclerosis. The association of C reactive protein concentration with coronary heart disease needs testing in prospective studies.