ESPE Abstracts

Background: The effects of GH deficiency (GHD) and GH replacement therapy (GHRT) on body composition and functional measures of physical fitness are largely unknown particularly in children.

Study aim: To evaluate body composition, muscular strength and flexibility, and exercise tolerance in GHD children at baseline and after one-year GHRT.

Patients and methods: We enrolled 19 children and adolescents with untreated GHD (mean age 10.54±1.66 years), and 19 healthy children (mean age 11.08±2.61 years) with normal GH reserve matched for age, stature and sex. At study entry, all subjects underwent: anthropometric measurements, multifrequency bioimpedance, a battery of tests evaluating exercise capacity (6-minute walking test (6MWT)), muscle strength (handgrip, jumping, sit-to-stand tests (STS)) and flexibility (sit-and-reach test). All the parameters were re-assessed after 1 year of GH treatment in GHD subjects.

Results: At baseline, GHD children had abnormal body composition, as indicated by higher values of waist-to-height ratio (WtHR) (0.50±0.08 vs 0.45±0.03, P = 0.02), fat mass (FM) (26.99±6.03 vs 22.78±5.52 %, P = 0.03), and lower fat-free mass (FFM) (22.45±5.11vs 28.68±7.39 kg, P = 0.03), compared to healthy controls. GHD children exhibited lower hand-grip strength (11.29±3.49 vs 14.03±4.7 kg; P = 0.04), vertical jump (12.78±4.17 vs 15.42±2.99 cm, P = 0.03), long jump (104.91±28 vs 114.03±34.3 cm, P = 0.03), and sit-and-reach test results (8.50±9.21 vs 14.50±7.75 cm, P = 0.03), 6MWT distance (505.31±67.25 vs 547.12±52.09 m, P = 0.04) compared to controls, indicating reduced muscular strength and flexibility and exercise tolerance. No differences were found in baseline (STS) or STS-5 repeats (STS-5R) tests between patients and controls. One-year GHRT in GHD patients improved body composition (FFM increased at 28.68±7.39 kg, P = 0.004, while FM% and WtHR reduced at 22.61±6.84%, P = 0.03, and 0.45±0.06, P = 0.02, respectively), handgrip strength (14.56±4.91, P = 0.001), vertical jump (16.02±4.81, P = 0.03), long jump (120.81±34.73, P = 0.03), 6MWT distance (603.31±79.45, P = 0.005) and sit-and-reach results (15.60±8.95, P = 0.02).

Conclusions: Preliminary results of our study provide the first evidence that untreated GHD is associated to altered body composition, and a reduction in functional measures of physical fitness, such as muscle strength and flexibility, and exercise tolerance, which are much relevant for the patient’s quality of life. Moreover, GHRT led to a normalization of such functional parameters over 1 year.