Endocrine Abstracts

Isolated hypogonadotropic hypogonadism (IHH) is known to decrease bone mineral density due to lack of pubertal surge of gonadotropins and deficiency of sex steroid hormone. Gonadal steroid hormones imbalance affects body composition. Nineteen Caucasian men, 22–48 year old (mean±S.D. 33±7.65) diagnosed with IHH (8 normosmic, 11 anosmic or hyposmic) were enrolled into the study. 14 patients were on hormone replacement therapy (HRT), 5 patients were started with HRT treatment. Nineteen healthy male volunteers (CON) with matched age and BMI were also included. Body composition and bone mineral density measurements were conducted with use of Air Displacement Plethysmography (BOD POD, Cosmed) and dual-energy x-ray absorptiometry DEXA (Lunar Prodigy,GE Healthcare), respectively. Hormonal status, lipid profile, calcium and phosphorus levels, 25-hydroxy vitamin D concentration were also measured. There was significant difference between fat-free-mass (FFM; kg) in IHH and matched controls (60.1 vs 66.0; P=0.012), related to Gynoid FFM distribution (IHH vs CON: 9.1 vs 10.3 kg; P=0.003). IHH patients have marked decreases in total bone mineral density compared to CON (1.21 vs 1.31 g/cm², P=0.009). Total bone mineral content, T-score and Z-score were also decreased in IHH subjects (2982 vs 3271 g/cm, P=0.05; 0.08 vs 1.06, P=0.016; −0.40 vs 0.54, P=0.013). High-density lipoprotein cholesterol (HDL) level was correlated with waist-to-height ratio (WHtR) (r=−0.81, P<0.05) in IHH patients. Significant correlations between insulin-like growth factor-1 (IGF-1) and WHtR were observed in IHH (r=−0.81, P<0.05; r=−0.82, P<0.05). Testosterone and 25Hydroxy vitamin D concentrations were not correlated with body composition and densitometry measurements. To conclude, IHH patient are at increased risk for osteoporosis. Long testosterone deficiency in IHH resulted in body composition changes related to fat free mass and distribution. WHtR, IGF-1 and HDL correlations in IHH patients might suggest their link with cardiometabolic dysfunctions. Susceptibility to metabolic syndrome in IHH patients on HRT should be further investigated.