y similar to those reported by the HapMap consortium for the CEU population. The genetic linkage between the tagging SNPs ranged from `weak’ to `moderate’. impedance) in the dominant inheritance model. In the additive model, only a trend was visible. However, this allele’s significant association in the dominant model and nominal association in the additive model with increased fasting leptin levels supports this SNP’s impact on overall adiposity. The adjusted effect size for this SNP’s effect on plasma leptin was 1.54 ng/mL per risk allele. Inclusion of bioelectrical ” impedance-derived percentage of body fat in the multiple regression analysis abolished this SNP’s association with plasma leptin showing that this effect on leptin is mediated by fat mass. In addition, the A-allele of rs12603825 revealed significant 16302825” association in the dominant model and nominal association in the additive model with increased total adipose tissue mass, as measured by MRI. The adjusted effect size of SNP rs12603825 was 1.22% of body weight per risk allele. The SERPINF1 SNP rs12603825 was not significantly associated with increased BMI, waist circumference, visceral adipose tissue mass, or intrahepatic lipids. The other SNPs did not show any reliable association with measures of body fat content and distribution. SNP associations with glycaemia and insulin sensitivity SNP associations with body fat content and distribution All SNP associations with body fat measures were studied after adjustment for gender and age. AT adipose tissue; BMI body mass index; BW body weight; MRI magnetic resonance imaging; MRS magnetic resonance spectroscopy; SNP single nucleotide polymorphism; available from 1,409 participants. doi:10.1371/journal.pone.0034035.t002 SERPINF1 and Adipose Tissue Mass To see whether SNP rs12603825 exerts an effect on insulin sensitivity via its effect on body adiposity, we excluded percentage of body fat as a confounder from the multiple regression analysis. In the dominant inheritance model, the minor A-allele of SNP rs12603825 was significantly associated with reduced clampderived insulin sensitivity, and this association was completely abolished after inclusion of percentage of body fat in the analysis. This provides evidence for an association of this SNP with insulin AVE8062A price resistance via promotion of body adiposity. , and with fasting plasma leptin concentrations. Discussion In this genetic study, we demonstrate in vivo functionality of the common SERPINF1 variant rs12603825 and its influence on overall adiposity with the minor A-allele representing the plasma PEDF- and body fat-elevating risk allele. Why we could not detect an impact of this SNP on BMI could have several reasons. One conceivable explanation could be the relatively low age of the subjects examined, as it is well-known that in young, physically active subjects BMI rather reflects muscle mass than fat mass. Another reason could be this SNP’s modest effect size on body adiposity of,8% that is presumably too small to be translated into significant changes in BMI at least in our cohort of limited sample size. Interrogation of publically available genome-wide analyses from the GIANT consortium again failed to reveal a significant association of SNP rs12603825 with BMI in approximately 250,000 subjects. The lack of association in this large sample could be due to confounders, such as ethnicity, environment, prediabetic status, and study methods, that were not accounted for in this study. Th