Improved tolerance to successive glucose loads in acromegaly

The mechanism of the Staub-Traugott effect, or facilitated glucose disposal with closely timed successive glucose loads, remains poorly understood. Progressive suppression of growth hormone has been suggested as an explanation. To test this hypothesis, three successive intravenous glucose loads were administered to seven active acromegalic patients and six healthy controls. All subjects showed a clear Staub-Traugott effect despite failure of hyperglycemia to suppress abnormally high growth hormone levels in the acromegalics. Except for higher basal and incremental insulin release in the acromegalic patients, patterns of insulin secretion and suppression of free fatty acids were not substantially different from controls. These studies clearly suggest that hyperglycemia-induced suppression of growth hormone is not the cause of the Staub-Traugott effect.