The effects of high serum growth hormone and IGF-1 levels on bone mineral density in acromegaly.

ABSTRACT

OBJECTIVE: Growth hormone (GH) and insulin-like growth factor-1 (IGF-1) play a major role in bone homeostasis. In this study, we aimed to assess bone mineral density (BMD) in active acromegaly. MATERIALS AND METHODS: A total of 29 patients with active acromegaly (age 46.10 ± 13.27 years; body mass index [BMI] 29.51 ± 4.91 kg/m2) and 42 healthy individuals matched for age and BMI (age 40.35 ± 11.74 years; BMI 28.18 ± 7.35 kg/m2) were included in the study. BMD was measured by DXA. RESULTS: The mean levels of GH and IGF-1 were found to be 12.61 ± 11.34 ng/ml and 676.47 ± 316.19 ng/ml in acromegaly, respectively, while the mean levels of GH and IGF-1 were found to be 0.59 ± 0.81 ng/ml (p = 0.0001) and 178.17 ± 57.11 ng/ml (p = 0.0001) in the control group, respectively. Only total hip t­score was determined to be significantly lower in acromegaly compared to the control group (p = 0.037). No significant differences were found between the other parameters in DXA and only a positive correlation was found between IGF-1 levels and L1-L4 BMD (r = 0.259, p = 0.029). CONCLUSIONS: Although GH and IGF-1 levels were increased in acromegalic patients, no significant difference was found in terms of vertebral BMD. Only hip t­scores were found to be lower in acromegalic patients, but this low hip t­score did not reach the osteopenic level. The positive correlation between IGF-1 and lumbar vertebral BMD suggested a more prominent effect of IGF-1 on BMD compared to GH.