A Modified Wingate Anaerobic Test May Be Used for the Evaluation of Growth Hormone Secretion in Children with Short Stature

Background: The diagnosis of growth hormone (GH) deficiency in children with short stature is complex and commonly done by pharmacologic provocation tests. There is a need for a physiological stimulation test such as exercise. We previously demonstrated that the traditional Wingate anaerobic test (WAnT) cannot be used as a GH provocation test. Therefore, we transformed the WAnT test to include shorter repetitions with recovery periods between them to mimic the usual physical activity performed by children. We hypothesized that the GH response to anaerobic test would be similar to the GH response to the commonly used pharmacologic provocation test.

Methods: Thirteen children (11 males and 2 females, age range 5.0–16.2 years) participated in the study. Each participant performed a modified WAnT including 10 cycles of all-out cycling for 15 seconds against constant resistance followed by 60 seconds of cycling without resistance. Blood samples for GH were collected before and 15, 30, 45, and 60 minutes after the beginning of exercise. In addition, we collected pre- and post- exercise blood lactate and cortisol levels. Children with abnormal GH secretion also performed the standardized pharmacologic test (clonidine or glucagon).

Results: There was normal GH secretion in 4 out of 13 children and 9 had subnormal GH secretion in the anaerobic test. Seven out of nine (77.8%) children with subnormal GH secretion also had a low GH secretion in the pharmacological test.

Discussion: The modified WAnT has a good correlation with the standard pharmacological GH provocation test and can be used as physiological test for GH secretion. Performing an exercise test to evaluate GH secretion may prevent the need to perform the commonly unpleasant provocation GH secretion tests in children.