Endocrine Abstracts

Glycogen storage disease type 1 is a rare autosomal recessive disorder. Osteoporosis is one of the long term complications. However factors associated with low bone mass has not fully understood. Metabolic derangements that occur with poor control may contribute to bone disease. Low bone mass could be caused by hypogonadtropic hypogonadism, a unique issue identified in GSD. Herein we report a patient with GSD type 1, osteoporosis and hypogonadotropic hypogonadism. A 20 years old man admitted to our outpatient clinic for evaluation of osteoporosis after femur fracture in 2021. He had a history of Glycogen Storage Disease type 1a that is diagnosed in infancy with recurrent hypoglycemia. He is currently managed with Glycosade however he has suboptimal metabolic control. He has multiple hepatic adenomas stable for two years on serial abdominal MR scans. He previously underwent a right lobe partial liver resection for probable hepatocellular carcinoma and pathology showed hepatic adenoma. On physical examination his height was 158 cm and weight was 54 kg. He has tanner 3 pubic hair and stage 4 genitalia. His biochemical tests confirmed hypogonadotropic hypogandism, other pituitary hormones were normal. His BMD at L1-L4 was 0.420 with a Z score of -6.0. At age 17 years he was evaluated for low bone mass. According to his medical records he underwent spontaneous puberty however his bone mineral density (BMD) at lomber vertebrae was 0.436 g/cm² and Z score -5.3 at that time. Vitamin D replacement was started nevertheless he did not use it regularly. Since there was not evidence for use of conventional osteoporosis treatment in Glycogen storage disease related osteoporosis we intended to treat his hypogonadism first. In 2021 at the age of 19 he was started on transdermal testosteron. After a year with transdermal testosteron his hepatic adenomas were stable in MR imaging. His bone mass ameliorated (L1-L4 BMD 0.648 g/cm² and Z score -4.7) despite his poor metabolic control. Hypogonadotropic hypogonadism may be an important factor contributing to bone loss in patients with GSD. Testosteron replacement may restore bone mass. GSD type 1 patients are at risk for potential malignant transformation of hepatic adenomas, testosterone therapy should be carefully monitored.