Several studies have shown H4 as associated with significantly lower CRP levels.[9], [16], [23], [24], [32] However, specifically of importance, few studies have assessed haplotypes, and H4 in particular, with risk of incident CHD. Thus far, the results have been unclear and conflicting. Though the Rotterdam Study did not genotype 2667G>C, they reported four haplotypes significantly associated with CRP levels, and reported no associations with CHD.[22] A recent study in the Cardiovascular Health Study of older adults reported no association between five CRP haplotypes and risk of MI among white participants, and the relative risk of MI for our H4 equivalent was 0.93 (95% CI 0.72–1.21).[24] On the other hand, though H4 was not associated with CRP levels in the Physicians' Health Study, 3872C>T individually was associated with lower CRP levels, and with an increased risk of MI (odds ratio: 1.29, 95% CI 0.99–1.67).[23] Furthermore, the odds ratio for 2667G>C was suggestive of a 50% increase as well, but the confidence interval was much wider. Taken together, these results suggest that 2667G>C and 3872C>T, though associated with lower CRP levels, may be associated with an elevated risk of CHD.
