Growth hormone and bone health

Area of Science:

• Endocrinology
• Bone Biology
• Metabolic Disorders

Background:

• Growth hormone (GH) and insulin-like growth factor-I are critical for bone cell development and skeletal growth.
• Childhood-onset GH deficiency (GHD) leads to significantly reduced linear growth and bone volume, impacting peak bone mass.
• Adult peak bone mass in untreated GHD individuals is approximately 50% of normal, with normal bone mineral density (BMD) but increased fracture prevalence.

Purpose of the Study:

• To investigate the effects of childhood- and adult-onset GH deficiency on bone mass, size, and fracture risk.
• To evaluate the efficacy of GH replacement therapy in correcting bone deficiencies and improving skeletal health.
• To explore the role of GH in bone remodeling and its potential therapeutic applications in other bone disorders.

Main Methods:

• Analysis of bone parameters (size, BMD, bone mineral content) in untreated adults with childhood-onset GHD.
• Review of cross-sectional surveys and KIMS data for adult-onset GHD patients regarding bone turnover and fracture incidence.
• Assessment of GH replacement therapy effects on BMD in controlled studies of adult-onset GHD.

Main Results:

• Childhood-onset GHD results in reduced bone volume and size, leading to significantly higher fracture rates despite normal true BMD.
• Adult-onset GHD is associated with decreased bone turnover and mild deficits in bone mineral content and BMD.
• GH replacement therapy over 18-24 months showed modest BMD increases in the lumbar spine and femoral neck in males with adult-onset GHD, with no significant changes in females.

Conclusions:

• GH deficiency, regardless of onset, compromises bone mass and strength, increasing fracture risk.
• Sustained GH therapy over 5 years can substantially improve bone size and mass.
• GH therapy holds potential for treating other bone disorders due to its positive impact on bone remodeling.