Human Fetuin-A Rs4918 Polymorphism and its Association with Obesity in Healthy Persons and in Patients with Myocardial Infarction in Two Hungarian Cohorts

Background: Human fetuin A (AHSG) has been associated with the development of obesity, insulin resistance, type 2 diabetes mellitus, and atherosclerosis. Observations on the role of AHSG rs4918 single-nucleotide polymorphism are contradictory. We investigated the association between variants of rs4918 and parameters of obesity, lipid status, tumor necrosis factor-alpha (TNF alpha), adipokines (adiponectin, resistin, leptin), and insulin resistance in healthy persons and in patients with previous myocardial infarction. Material/Methods: This was a cross-sectional study comprising cohort 1 (81 healthy individuals) and cohort 2 (157 patients with previous myocardial infarction). We used the allele-specific KASP genotyping assay to detect rs4918 polymorphism. Results: In cohort 1, G-nucleotide carriers had significantly lower serum TNFa, adiponectin, and higher leptin concentrations than in non-G carriers. These differences, however, were not observed in cohort 2. In cohort 2, G-carriers had lower BMI and waist circumferences than in non-G carriers. The G allele was more frequent among lean than obese patients (RR=1.067, 95% CI=1.053-2.651, p=0.015). An association between BMI and rs4918 polymorphism was observed among patients without diabetes (CC/CG/GG genotypes: p=0.003, G vs. non-G allele: p=0.008) but not in diabetics. In addition, a strong linearity between BMI and the CC/CG/GG genotypes (association value: 4.416, p=0.036) and the frequency of the G allele (7.420, p=0.006) could be identified. In cohort 2, non-obese, non-diabetic G-carriers still had lower BMI and waist circumferences than in non-G carriers. Conclusions: The rs4918 minor variant is associated with lower TNFa and adiponectin, higher leptin levels in healthy persons, and more favorable anthropomorphic parameters of obesity in cohort 2.