An aromatase polymorphism modulates the relationship between weight and estradiol levels in obese men

ObjectiveTo describe the influence of the TTTA aromatase polymorphism (TTTAn) on the relation between obesity and plasma estradiol (E2) in obese men.DesignA 2-year cohort study.SettingClinical research center.Patient(s)Severely obese men (31 who had had gastric bypass surgery and 118 controls).Intervention(s)Men were genotyped for the TTTAn CYP19A1 polymorphism. Anthropomorphic measures, plasma E2, and other hormonal levels were determined at baseline and 2-year follow-up.Main Outcomes Measure(s)Relationships between weight and changes in weight and plasma E2 were examined in relation to the TTTAn polymorphism.Result(s)The mean age was 46.5 ± 10.82 years, and mean body mass index was 47.1 ± 8.46 kg/m2. The most common repeats were 7 and 11. TTTAn number did not correlate with plasma E2 in the univariate analysis. When patients were stratified per weight group, the correlation between plasma E2 and weight was seen only among men with a higher TTTA repeat at baseline and 2 years. Similarly, only men with higher TTTA exhibited reduced E2 levels after weight loss.Conclusion(s)A higher TTTA repeat is associated with a strengthened relationship between obesity and E2. The well-established effect of increased weight on plasma E2 appears to be absent in men with low TTTA numbers.