The effect of hyperglycemia on growth hormone, thyroid-stimulating hormone, and prolactin response to oral diazepam (10 mg) was assessed in 7 normal subjects. A peak growth hormone response of 13.5 +/- 0.3 ng/ml (mean +/- SEM) significantly above the base line (p less than 0.001) was achieved when diazepam was given alone. Hyperglycemia after glucose load abolished this response. There was no significant response of thyroid-stimulating hormone or prolactin after the administration of oral diazepam with and without glucose.