Introduction: Hypogonadism occurs in myotonic dystrophy (DM) type 1 and 2, a multisystemic autosomal dominant disorder with insulin resistance and visceral obesity. DM patients provide a model to investigate the impact of metabolic alterations on hypogonadism.
Methods: We assessed Leydig and Sertoli cell functions and metabolic features in 32 DM1 (44+11 years),13 DM2 patients (54+9 years) and 32 age and BMI-matched controls.
Results: Overt primary hypogonadism (sexual dysfunction, total T<320 ng/dl) occurred in 26% of DM1 and 38% of DM2 patients. Increased LH was detected in 68% of DM1 and in all DM2. INSL3, marker of Leydig cell function, was lower in hypogonadal than in eugonadal patients and in controls. Anamnestic recall suggested reduced fertility in 34% of DM patients. AMH and inhibin-B, markers of Sertoli cell function, were dramatically reduced in DM than controls. FSH levels were elevated in 68% DM1 and in all DM2. DM patients showed an increased visceral body fat: waist/hip and body fat mass were higher than in controls; hepatosteatosis and increased epicardial fat thickness occurred in >50% of cases. Dyslipidemia also was frequent (62%). Diabetes mellitus and insulin resistance were higher in DM2 (38 and 61%) than in DM1 (3 and 21%). Both HOMA-IR and body fat mass negatively correlated with freeT levels in DM patients. In DM1 patients AMH levels correlated positively with muscle strength, muscle mass, resting energy expenditure and negatively with clinical score. Furthermore, AMH negatively correlated with fat mass and waist/hip. In DM2 patients AMH was positively related with muscle strength, while it is not influenced by metabolic features and fat mass.
Conclusion: Hypogonadism is very frequent in DM patients and linked with muscle impairment. This study firstly demonstrates that hypogonadism in DM is associated with reduced levels of INSL-3, AMH and inhibin B and is negatively influenced by visceral adiposity.
Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.
Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.
05 - 09 May 2012
European Society of Endocrinology