Background: Klinefelter syndrome (KS) is a frequent anomaly of sex chromosomes, due to the presence of an extra X chromosome (one or more) in the karyotype 46, XY. This disease is characterized by hypergonadotropic hypogonadism and a high risk of developing disorders of carbohydrate and fat metabolism, despite the absence of a pronounced androgen deficiency in adolescents with KS. There are reports of changes in body composition in adolescents with KS even before the symptoms of hypogonadism appear. Objective: To analyse the body composition and resting metabolic rate (RMR) among adolescents with KS. Patients and methods: We examined 20 adolescents with KS, comparable in age and the puberty stage according to Tanner classification. Patients were divided into 2 groups depending on the presence or absence of signs of hypogonadism (reduced level of testosterone, eunuchoid body shape). We investigated the hormonal profile, evaluated the body composition using the Tanita (Japan) body composition analyzer BC-418MA and determined the RMR using the indirect calorimetry method in all children. We used the RMR indicator adjusted for the lean mass (LM) - RMR/LM.
|Number of patients||Age, |
|Bone age, years||Puberty stage||Testosterone, |
|Body fat, |
|KS with signs of hypogonadism||7||15.32|
|3 [3;4]||8.66 |
|KS without signs of hypogonadism||13||16.04|
|4 [3;4]||11.4 |
Results: 1) Among 20 adolescents with KS 60% (n=12) showed normal resting metabolic rate, 25% showed reduced metabolism (n=5), 15% had increased metabolism (n=3).
2) Normal body composition was detected in 65% of the patients (n=13), excess fat was detected in 25% (n=5), 10% had fat deficiency (n=2).
3) Correlation analysis revealed average positive correlation between the amount of LM and RMR (r=0.59, P <0.05) and a strong positive correlation with SDS BMI (r=0.78, P <0.05).
4) The correlation analysis of the RMR/LM did not reveal its connection with blood testosterone levels.
5) Comparative analysis of two groups of patients with KS revealed no differences in terms of RMR/LM.
Conclusions: Most patients with KS in our study revealed normal indices of body composition and RMR regardless of the level of testosterone. No correlation between the basal metabolism and the level of testosterone may indicate a slight effect of androgen deficiency on energy metabolism at rest in adolescents with KS.
19 - 21 Sep 2019
European Society for Paediatric Endocrinology