Lack of relationship between 174G_C promoter polymorphism of the IL-6 gene and indices of metabolic syndrome in non-obese healthy subjects

Homozygosity for interleukin-6 (IL-6) 174G_C promoter polymorphism has recently been associated with indices of metabolic syndrome; however, this problem has not been investigated in non-obese subjects. The aim of this study was to explore the relation between abdominal fat distribution and some inflammatory risk factors of atheromatosis and IL-6 174G_C gene polymorphism in non-obese healthy subjects.Relationships were investigated between anthropometric variables, i.e. weight, height, BMI, waist circumference (WC), waist-to-hip ratio (WHR), body fat distribution (DXA), serum CRP and IL-6, insulin sensitivity/resistance indices, and IL-6 174G_C gene polymorphism, in healthy non-obese Polish subjects: 232 women (age 31.4 +/- 5.5 years) and 199 men (age 30.3 +/- 6.0 years).The genetic study revealed that the CC genotype was observed in 15.56% of subjects, the CG genotype in 52.74%, and the GG genotype in 31.7%. IL-6 and CRP concentration did not differ among the genotypes. There were also no differences regarding BMI and WHR. The only differences among genotypes, observed only in men, were those concerning total fat (CC had higher fat content than CG and GG); the difference being statistically significant between CC and GG (p0.05), and gynoidal fat deposit (CC had higher gynoidal fat deposit than CG and GG); the difference being statistically significant between CC and GG (p0.025) and between CC and CG (p0.05). Biochemical parameters and insulin sensitivity did not differ among the genotypes.These data show that IL-6 174G_C polymorphism is not associated with features describing metabolic syndrome in nonobese healthy subjects.