Protocol TRANS and QT Repolarization

"A triplicate ECG and a blood test will be done during a medical consultation as part of the usual endocrinology follow-up. Included individuals seen prior to initiation of GAHT, will be assessed a second time (at least one month after GAHT start) with a triplicate ECG and a blood test similar to inclusion visit. Included individuals already on GAHT will be seen only once at the inclusion visit.~Triplicates of 10seconds 12-lead digitized electrocardiogram will be recorded after few minutes of rest in the supine position. Electrocardiograms will be acquired with Mindray ECG BeneHeart R12. For each subject, RR, PR, QRS and QT interval durations will be assessed with a semiautomatic approach using the median representative beats (overlap method) generated from 10seconds ECG with a good quality (CalECG v3.7; AMPS, LLC). The QT interval will be measured and corrected for heart rate by Fridericia's formula."

Blood samples for the determination of serum concentrations of estradiol, progesterone, testosterone, FSH, and LH will be collected on the same day as the ECG, in a dry tube and further assayed in the immunology laboratory of Bordeaux University Hospital (France). Estradiol, progesterone, FSH, and LH plasma concentrations will be assayed by immunochemiluminescence (Architect i2000SR; Roche Diagnostics), and testosterone levels by liquid chromatography mass spectrometry. Kalemia and calcemia will be collected in a BD Vacutainer tube with heparin lithium and separator, further assayed at the biochemistry laboratory of Bordeaux University Hospital by indirect potentiometric measurement (Architect c16000) and Arsenazo III SRM 956 colorimetrie (Architect c16000).