GH1 and obesity due to melanocortin 4 receptor deficiency: Since the ratio of 22 kDa- to 20 kDa-GH is constant after exercise and independent from the protocols of exercise as in normal-weight subjects, hyposomatotropism in obesity does not seem to depend on an unbalance of circulating GH isoforms and exercise-induced GH response is unlikely to affect the reliability of direct methods for detection of rhGH abuse in overweight/obese athletes.