Associations between Serum C-reactive Protein (CRP) Levels and Polymorphisms of CRP, Interleukin 1B, and Tumor Necrosis Factor Genes among Japanese Health Checkup Examinees

C-reactive protein (CRP) is a sensitive marker of acute inflammation, which is associated with risk ofcardiovascular and other chronic diseases. Some CRP polymorphisms are reported to affect the basal andstimulated CRP levels. Thus we conducted a population-based cross-sectional study to examine the associationsof CRP levels with CRP C1444T polymorphism and two cytokine polymorphisms (IL-1B C-31T and TNF-A T-1031C), according to sex, age, smoking, alcohol, and BMI, in a total of 489 Japanese health checkup examinees(156 males and 333 females). Serum CRP levels were measured by high sensitivity latex-enhanced nephelometry.CRP C1444T, IL-1B C-31T and TNF-A T-1031C genotypes were genotyped by PCR-CTPP (polymerase chainreaction with confronting two-pair primers). Males, aged, smokers, and those with high BMI had a higher CRPon average. All genotype frequencies among the 489 subjects were in Hardy-Weinberg equilibrium. No significantassociations of serum CRP levels with the genotypes of CRP C1444T and IL-1B C-31T were observed. TNF-A -1031CC polymorphism was significantly associated with high CRP values. For the females, those aged 61-69years, never smokers, non-drinkers, or those with body mass index 24 or less, the association was remarkable.Since the biological mechanism is not clear, further investigations are required to confirm the association.