Short QTc Interval in Males with Klinefelter Syndrome-Influence of CAG Repeat Length, Body Composition, and XXXX Replacement Therapy.

@entity1 @entity251 @entity12396 @entity252 @entity2689 @entity13198
BACKGROUND: @entity252 ( @entity252 ) is a sex chromosomal aneuploidy (47,XXY) affecting 1/660 males. Based on findings in @entity2689 , we hypothesized that electrocardiogram (ECG) abnormalities would be present in males with @entity252 . OBJECTIVE: To investigate ECGs in males with @entity252 and compare with controls. METHODS: Case control study of 62 males with @entity252 and 62 healthy males matched on age. The primary outcome parameter was a difference in the ECG presentation between the two groups. The ECGs were analyzed by one blinded examiner (intraobserver variability 0.2-2.1%). The QT-interval was measured using "teach-the-tangent" method excluding the U-wave. QTc was calculated using Bazett's equation, Hodges' equation, and a linear regression model. Body mass index, abdominal fat, and muscle mass as well as sex hormone levels were secondary parameters. The prevalence of mutations in genes related to @entity12396 was determined in @entity1 with a QTc < 330 ms. RESULTS: Compared to controls, the @entity13198 was shorter (P = 0.02-0.06) in males with @entity252 depending on the applied correction method. QTc was shortest among @entity251 (T)-treated males with @entity252 , while untreated and thus hypogonadal @entity252 had QTc interval comparable to controls. No mutations in genes related to @entity12396 were found. CONCLUSION: We found short QTc interval in males with @entity252 , with further shortening of the QTc interval by T. These results suggest that genes on the X chromosome could be involved in regulation of the QTc interval and that T treatment may aggravate this mechanism.
