SUN-310 Growth Hormone Deficiency and Replacement Therapy: Association with Health-Related Physical Fitness

Objective: To compare health-related physical fitness (HRPF) in patients with severe adult growth hormone deficiency (AGHD) according to the deficiency onset phase, and to evaluate the effects of a six-months human growth hormone (rhGH) replacement therapy on HRPF, in a subgroup of patients. Methods: First arm: cross-sectional observational study at baseline of naive rhGH multiple pituitary hormonal deficiency (MPHD) hypopituitarism patients - adult-onset growth hormone deficiency (AO-GHD) versus child onset growth hormone deficiency (CO-GHD). Second arm: a 6-month intervention clinical trial in a selected group of a non-randomized, non-controlled cohort. HRPF was evaluated by measuring isokinetic and isometric torque stensor strength at the knee using an isokinetic dynamometer, handgrip strength and six-minute walk test. Body composition was assessed by DXA. Results: Patients who presented AO-GHD had higher BMI than CO-GHD (28.1±3.5 x 22.4±4.8; p=0.017), but body composition (lean body mass%:57.9±7.9 x 58.9±8.6;p=0.816/fatty body mass%:39.3±6.8 x 36.0±9.1;p=0.434), stensor peak torque/body weight at 60, 90 and 180deg/s (2.18±0.6 x 2.18±0.6; p=0.580/1.99±0.5 x 2.14±0.5;p=0.546/1.52±0.4 x 1.64±0.4;p=0.547), isometric torque/body weight at the knee (2.62±0.7 x 2.91±0.6;p=0.357) and six-minute walk test (570.2±76.0cm x 554.1±91.0cm;p= 0.703) did not differ between groups. Handgrip strength test also showed significant reduction in scores for age and gender in both groups of GHD patients. After six months of rhGH, no improvement in muscular strength tests was found. There was a significant worsening in the six-minute walk test (575.1±84cm x 545.4±90.6cm; p=0.033) despite the improvement in body composition (lean body mass%:59.7±8.6 x 63.6±11.1;p=0.005/fatty body mass%:35.7±9.2 x 32.9±10.0;p=0.003). Conclusion: Despite differences in BMI, there were no other differences in HRPF between AO-GHD and CO-GHD patients. The decrease of the six-minute walking test performance after rhGH replacement therapy supports the clinical evidence that the GH regulates bioenergetics in human skeletal muscle fibers. Although the treatment had a short period, GH might have stimulated the anaerobic and suppressed the aerobic energy system.