Men with Congenital Hypogonadotropic Hypogonadism (CHH) and Kallmann syndrome (KS) have both low circulating testosterone and estradiol levels. Whether bone structure is affected remains unknown.To characterize bone geometry, volumetric density and microarchitecture in CHH/KS.Cross-sectional study.One tertiary academic French center.51 genotyped CHH/KS patients and 40 healthy volunteers were included. Ninety-eight percent of CHH/KS men had received testosterone and/or combined gonadotropins.High-resolution Peripheral Quantitative Computed Tomography (HR-pQCT), Dual X-ray absorptiometry (DXA) and measurement of serum bone markers.Volumetric bone mineral density (vBMD), cortical and trabecular microarchitecture.CHH and controls did not differ for age, BMI, vitamin D and PTH levels. Despite long-term hormonal treatment (10.8 ± 6.8 years), DXA showed lower areal BMD in CHH/KS at lumbar spine, total hip, femoral neck and distal radius. Consistent with persistently higher serum bone markers, HR-pQCT revealed lower cortical and trabecular vBMD as well as cortical thickness at the tibia and the radius. CHH/KS men had altered trabecular microarchitecture with a predominant decrease of trabecular thickness. Moreover, CHH/KS men exhibited lower cortical bone area, whereas total and trabecular areas were higher only at the tibia. Earlier treatment onset (before the age of 19 years) conferred a significant advantage for trabecular bone volume/tissue volume and trabecular vBMD at the tibia.Both vBMD and bone microarchitecture remain impaired in CHH/KS men despite long-term hormonal treatment. Treatment initiation during adolescence is associated with enhanced trabecular outcomes, highlighting the importance of early diagnosis.
Agnès Ostertag, Georgios E Papadakis, Corinne Collet, Severine Trabado, Luigi Maione, Nelly Pitteloud, Jerome Bouligand, Marie Christine De Vernejoul, Martine Cohen-Solal, Jacques Young