QUADRICEPS AND HANDGRIP STRENGTH IN ADULTS WITH CHILDHOOD-ONSET GROWTH-HORMONE DEFICIENCY

The effects of chronic growth hormone (GH) deficiency on muscle size a nd strength of postural (quadriceps) and non-postural (hand-grip) musc le groups, as well as on vertical jump capacity, were evaluated in six adults with childhood-onset GH deficiency. Data obtained were compare d to those recorded in an age-, sex- and exercise-matched healthy cont rol group. Thigh muscle plus bone cross-sectional area (CSA(M+B)) of t he dominant quadriceps was significantly lower (p < 0.001) than in con trols, while the CSA(M+B)/(Body height)(2) ratio was similar to that o f controls. The maximum voluntary contraction (MVC) of the quadriceps of patients was significantly lower (p < 0.002) than in controls, whil e no differences existed in the quadriceps force expressed per unit ar ea (MVC/CSA) between patients and controls. As far as hand-grip was co ncerned, the CSA(M+B) of the dominant forearm was significantly lower (p < 0.003) than in controls, while the CSA(M+B)/(Body height)(2) rati o was no different. The hand-grip MVC of patients was significantly lo wer (p < 0.004) than in controls, while no differences existed in the MVC/CSA ratio. It is noteworthy also that no difference existed in the hand-grip to quadriceps MVC ratio of the two groups. Furthermore, no differences were found in the vertical jump capacity, because both Del ta Height and Delta Height/Body weight of patients were not significan tly different from those of controls. In conclusion, our study suggest s that GH deficiency seems to reduce the size and strength of postural and non-postural muscle groups to the same extent. However, these fin dings are likely to be attributed to a simple dimensional scaling, bec ause their CSA/(Body height)(2), MVC/CSA and vertical jump capacity we re comparable to those of controls.