Plasma ferritin levels, genetic variations in HFE gene, and coronary heart disease in Chinese: a case-control study.

BACKGROUND: The association between body iron stores and coronary heart disease (CHD) was inconsistent. We sought to explore this association in Chinese Han population and further examine the association of the variations in hemochromatosis (HFE) gene and CHD risk. METHODS: We conducted a case-control study including 1334 CHD patients and 1334 age- and sex-frequency matched controls. The plasma ferritin levels were measured by enzyme linked immunosorbent assay. Genotypes of the tagging single nucleotide polymorphisms (tagSNPs) were determined by TaqMan SNP allelic discrimination. RESULTS: The plasma ferritin levels in CHD cases (197.9µg/L [2.7-932.9µg/L]) were higher than those in controls (179.9µg/L [21.1-878.2µg/L]; P=0.028). The odds ratios (ORs) across the tertiles of plasma ferritin levels were 1.0 (reference), 0.93 (0.76-1.13), and 1.23 (1.02-1.48; P for trend=0.028). Adjustment for the traditional risk factors attenuated the associations to null (P for trend=0.22). Compared with the TT genotype of tagSNP rs9366637, subjects with C allele had higher risk of CHD (OR=1.35 for TC and 1.76 for CC; P=0.001 and <0.001 respectively). After adjustment for the conventional risk factors the results remained unchanged. We did not find significantly different plasma ferritin levels among different genotypes of rs9366637 (P=0.52). CONCLUSIONS: The plasma ferritin levels were not significantly associated with CHD risk. However, the SNP rs9366637 in HFE gene was associated with higher CHD risk in Chinese Han population. The underlie mechanism remained to be elucidated in further studies.