Very Low Levels of High-sensitivity C-reactive Protein are not Bimodally Distributed but are Significantly Related to Other Metabolic Risk Factors in Japanese

Background High-sensitivity C-reactive protein (hs-CRP) is an independent risk factor of diabetes and cardiovascular disease and it is proposed as a component of metabolic syndrome. Blood levels of hs-CRP are reported to be much lower in Japanese than in Westerners and bimodally distributed in Japanese. Methods Very low levels of hs-CRP were examined using medical check-up data of 1,360 Japanese men and 821 women whose plasma levels of high-sensitivity C-reactive protein (hs-CRP) were below 10 mg/L. Results The distribution of hs-CRP levels were skewed but not bimodal in both men and women and very low levels of hs-CRP were significantly related to waist circumference, systolic blood pressure, diastolic blood pressure, fasting glucose, triglycerides, and low-density lipoprotein cholesterol in both men and women. The area under receiver operating characteristic curve of hs-CRP for diagnosing metabolic syndrome and Spearman's correlation coefficients between hs-CRP and components of metabolic syndrome were comparable to those of components of metabolic syndrome in both men and women. Conclusion Very low levels of hs-CRP were not bimodally distributed but were significantly related to metabolic risk factors in Japanese.