PPARγ Pro12Ala and ACE ID polymorphisms are associated with BMI and fat distribution, but not metabolic syndrome

BACKGROUND: Metabolic Syndrome (MetS) results from the combined effect of environmental and genetic factors. We investigated the possible association of peroxisome proliferator-activated receptor-γ2 (PPARγ2) Pro12Ala and Angiotensin Converting Enzyme (ACE) I/D polymorphisms with MetS and interaction between these genetic variants. METHODS: Three hundred sixty four unrelated Caucasian subjects were enrolled. Waist circumference, blood pressure, and body mass index (BMI) were recorded. Body composition was estimated by impedance analysis; MetS was diagnosed by the NCEP-ATPIII criteria. A fasting blood sample was obtained for glucose, insulin, lipid profile determination, and DNA isolation for genotyping. RESULTS: The prevalence of MetS did not differ across PPARγ2 or ACE polymorphisms. Carriers of PPARγ2 Ala allele had higher BMI and fat-mass but lower systolic blood pressure compared with Pro/Pro homozygotes. A significant PPARγ2 gene-gender interaction was observed in the modulation of BMI, fat mass, and blood pressure, with significant associations found in women only. A PPARγ2-ACE risk genotype combination for BMI and fat mass was found, with ACE DD/PPARγ2 Ala subjects having a higher BMI (p = 0.002) and Fat Mass (p = 0.002). Pro12Ala was independently associated with waist circumference independent of BMI and gender. CONCLUSIONS: Carriers of PPARγ2 Ala allele had higher BMI and fat-mass but not a worse metabolic profile, possibly because of a more favorable adipose tissue distribution. A gene interaction exists between Pro12Ala and ACE I/D on BMI and fat mass. Further studies are needed to assess the contribution of Pro12Ala polymorphism in adiposity distribution.