Glucose-induced hyperkalaemia: A hazard for diabetics?

Area of Science:

• Endocrinology
• Metabolic Disorders
• Clinical Chemistry

Background:

• Intravenous glucose administration is sometimes used as a diagnostic test in comatose diabetic patients.
• The physiological response to glucose in insulin-deprived diabetics requires further investigation, particularly concerning electrolyte balance.

Purpose of the Study:

• To investigate the effect of oral glucose administration on plasma potassium levels in insulin-dependent diabetics who have withheld insulin.
• To compare the response in diabetics with that of non-diabetic individuals.

Main Methods:

• Eight insulin-dependent diabetics withheld insulin for 14-26 hours before receiving 50g of oral glucose.
• Plasma potassium and osmolality were measured before and after glucose intake.
• Non-diabetic controls underwent the same glucose challenge.

Main Results:

• A prompt rise in plasma potassium and plasma osmolality was observed in insulin-deprived diabetics after glucose intake.
• In contrast, plasma potassium levels decreased in non-diabetic controls following glucose administration.
• The observed potassium increase in diabetics may be linked to osmotic and hormonal factors.

Conclusions:

• Oral glucose can induce a paradoxical rise in plasma potassium in insulin-deprived diabetics.
• This effect may have clinical significance, warranting caution or discontinuation of intravenous glucose as a therapeutic test in this population.