Growth hormone treatment in growth hormone-deficient adults. I. Effects on muscle mass and strength

Abstract

The effect of recombinant DNA human growth hormone (rhGH) treatment in adults with growth hormone (GH) deficiency was studied in 24 patients in a double-blind placebo-controlled trial. The dose was 0.07 U/kg body wt daily. After 6 mo of treatment, significant increases were noted in the rhGH group for total cross-sectional area of thigh muscle (+11.2 +/- 3.1 vs. -0.5 +/- 3.0 cm2; P = 0.015 vs. placebo) and quadriceps muscle (+4.1 +/- 0.8 vs. +0.4 +/- 1.2 cm2; P = 0.031) measured by computerized tomography. Strong correlations were noted between lean body mass (measured as total body potassium) and total thigh muscle area in normal and GH-deficient adults both before and after rhGH treatment. Strength of hip flexors (+1.25 +/- 0.27 vs. +0.25 +/- 0.12 z-scores; P = 0.004) and limb girdle muscles increased (P = 0.02) in the rhGH group. We conclude that 1) rhGH increases lean tissue and skeletal muscle mass in adults with human GH deficiency, 2) this suggests a role for GH in the regulation of body composition of adult humans, 3) the increase in strength of limb girdle muscles after rhGH treatment suggests that adults with GH deficiency may have a proximal myopathy, and 4) the failure to demonstrate an increase in strength in other muscle groups may require the study of larger numbers of patients.

Muscle strength in elderly adults with GH deficiency after 10 years of GH replacement

“…The results of several studies suggest that the reduced muscle strength in young GHD adults can be reversed by GH replacement (3,(7)(8)(9)(10). However, absolute values of muscle strength returned towards baseline values between 5 and 10 years of GH replacement in GHD adults of various ages in one study (10).…”

Relationship of chronic endurance exercise to the somatotropic and sex hormone status of older men

“…Although mechanisms responsible for this phenomenon are incompletely understood, impaired GH release in response to a variety of physiologic and pharmacologic stimuli has been repeatedly documented (3,4). Adults with complete GH deficiency typically manifest a reduced lean body mass and muscle strength, an increased fat mass and a reduced exercise capacity (5,6). These abnormalities can be at least partially corrected by GH replacement (5)(6)(7)(8).…”

“…Adults with complete GH deficiency typically manifest a reduced lean body mass and muscle strength, an increased fat mass and a reduced exercise capacity (5,6). These abnormalities can be at least partially corrected by GH replacement (5)(6)(7)(8).…”

Hormônio do crescimento e exercício físico: considerações atuais

“…Em situações de ausên-cia ou redução acentuada da síntese do GH, verifica-se diminuição na quantidade de massa muscular, força e resis-tência muscular (Rudman et al, 1990;Rennie, 2003). Normalmente, em indivíduos deficientes de GH ou idosos (≥ 60 anos), a reposição do hormônio resulta em aumento na força, na massa muscular e no Volume Máximo de Oxigênio (VO 2máx ) e submáximo (Cuneo et al, 1991a;Cuneo et al, 1991b;Borst, 2004).…”

“…Em um estudo foi avaliado o efeito da administração de GH (40 µg/kg/dia ou 0,1 UI/kg/dia) em indivíduos saudáveis submetidos a um período de 12 semanas com exercícios físicos resistidos, realizados 5 vezes por semana em intensidade de 75-90% da força máxima (4 a 8 repetições) (Yarasheski et al, 1992 Cuneo et al, 1991a;Cuneo et al, 1991b;Borst, 2004;Yarasheski et al, 1992;Healy et al, 2003. Aumento no VO 2 máx Indivíduos deficientes de GH ou idosos (≥ 60 anos) Cuneo et al, 1991a;Cuneo et al, 1991b;Borst, 2004 poral em ambos os grupos.…”