47,XXY, Klinefelter Syndrome, Sex Chromosome Aneuploidy, XXY Syndrome
Conditions
Keywords
Klinefelter syndrome, XXY, Sex chromosome aneuploidy, sex chromosome variation, hypogonadism, cardiometabolic, body composition, exercise capacity
Brief summary
This study plans to learn more about how to measure the way the the body's energy system works in boys with Klinefelter syndrome, including the heart, lungs, muscles, and liver. This is important to know so that investigators understand how hormones and an extra X chromosome relate to diseases such as diabetes, extra weight gain, heart disease and liver diseases.
Detailed description
Klinefelter syndrome (KS) is the most common chromosomal abnormality in males and is associated with primary gonadal failure in adolescence and a high morbidity and mortality from cardiovascular-related diseases (CVD) in adulthood. Recent studies in children and adolescent boys with KS have found a high prevalence of CVD risk markers, however the underlying mechanisms have not been explored. Our central hypothesis is that pubertal boys with KS have relative testosterone deficiency resulting in abnormal energy metabolism that predisposes them to later CVD, and that exogenous testosterone will modify these abnormalities. In this study, investigators will measure markers of cardiometabolic risk in pubertal boys with KS.
Interventions
OTHERNo intervention
Sponsors
University of Colorado, Denver
Study design
Observational model
CASE_ONLY
Time perspective
CROSS_SECTIONAL
Eligibility
Sex/Gender
MALE
Age
12 Years to 17 Years
Healthy volunteers
No
Inclusion criteria
* Male, 47,XXY karyotype (non-mosaic) * Age 12-17 years * Tanner stage 3-5 pubic hair * T naïve group only: No exogenous androgen exposure within the past 5 years * T exposed group only: currently on topical testosterone, with duration of treatment between 1-2 years.
Exclusion criteria
* Cognitive, psychiatric, or physical impairment resulting in inability to tolerate the study procedures * MRI incompatible metal * Diagnosis of type 1 or type 2 diabetes * Hypertension greater than 140/90 mm/Hg at rest (would make exercise studies unsafe) * Weight \> 300 lbs (limit for DEXA) * Testosterone treatment for \<1 year or \>2 years
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| VO2 peak | baseline | The primary outcome will be peak oxygen consumption (VO2 peak) during exercise on a bicycle ergometer |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Body composition | baseline | Percent body fat by dual-energy x-ray absorptiometry |
| Liver fat | baseline | Intrahepatic fat by abdominal magnetic resonance imaging |
| Muscle mitochondrial metabolism | baseline | Rate of mitochondrial phosphorylation by 31-phosphorus magnetic resonance spectroscopy of the calf muscles |
| Insulin sensitivity | baseline | oral disposition index with Glucola |
Countries
United States
Outcome results
None listed