Gonadal failure is associated with visceral adiposity in myotonic dystrophies

Background Hypogonadism occurs in myotonic dystrophies type 1 ( MD 1) and type 2 ( MD 2). Sertoli and Leydig cell secretions, including insulin‐like peptide‐3 ( INSL 3), anti‐Müllerian hormone ( AMH ) and inhibin B, were evaluated in male patients with MD . Design Academic settings. Forty‐four male patients with MD [31 MD 1, 13 MD 2, aged 59 (50–64) years, median (interquartile range)], age‐, sex‐ and BMI ‐matched non‐ MD hypogonadal patients ( n  = 14) and healthy controls ( n  = 32). Serum FSH , LH , inhibin B, AMH , testosterone (T) and INSL 3 were measured; fat and muscle masses were evaluated by DEXA . Results Overt primary hypogonadism occurred in 29% of patients with MD 1 and 46% of patients with MD 2. Considering subclinical forms, the prevalence increased to 69% of MD 1 and 100% of MD 2. A half of patients with MD experienced symptoms. INSL 3 levels were unaffected in most patients with MD . By contrast, AMH and inhibin B were reduced in most patients with MD and unrelated to age. Patients with MD showed increased body and visceral fat. Free T levels were negatively predicted by fat mass, and AMH and FSH levels were negatively correlated with waist/hip ratio and fat mass. AMH , inhibin B and FSH levels positively correlated with muscle strength and muscle mass. Conclusions AMH and inhibin B secretion failures are common in male patients with MD and are more severe than Leydig cell hormones impairment. AMH and inhibin B measurements might provide clinical utility in evaluating fertility in patients with MD . Serum T, AMH and inhibin B productions are negatively influenced by increased fat mass, while AMH and inhibin B might be markers of muscle impairment.