Factors determining high-sensitivity C-reactive protein values in the Spanish population. Di@bet.es study

Although high-sensitivity C-reactive protein (hs-CRP) is currently used as a risk marker of cardiovascular disease, it has been suggested that genetic, clinical, biochemical or environmental factors could modify hs-CRP levels. The aim of this study was to investigate sources of interindividual hs-CRP variability in the Spanish population.

A representative sample of the Spanish population within the di@bet.es study was used. Study variables included a clinical and demographic structured survey, a lifestyle survey, a physical examination, plasmatic hs-CRP and other biochemical parameters.

Median and interquartile range of plasma hs-CRP values were 1·73 ± 2·75 mg/dL. Thirty per cent of the study population had hs-CRP levels above 3 mg/dL and 38% from 1 to 3 mg/dL. Body mass index was the strongest factor associated with moderate and high hs-CRP levels. Age, sex, waist-to-hip ratio, weight increase, plasma lipid levels, glucose metabolism (HOMA-IR and abnormal glucose regulation categories), pharmacological treatment (lipid-lowering agents, psychotropic drugs and levothyroxine), smoking, physical activity, different dietary patterns, quality of life and educational level were all significantly associated with hs-CRP levels. Interactions were observed between variables. These interactions modulated the effect of previously described factors on hs-CRP.

Thirty per cent of the Spanish population have hs-CRP levels considered to represent a cardiovascular risk. Different clinical, anthropometric, biochemical and environmental variables modulate hs-CRP levels. In addition, multiple interactions between variables complicate the interpretation of hs-CRP values.