Relation between the Urinary Cortisol: Creatinine Ratio and Hypoglycaemia

Abstract

The relationships between (i) urinary free cortisol and urinary creatinine concentrations and (ii) the urinary cortisol/creatinine ratio (UCCR) and various glycaemic levels were studied in three groups—normal, insulin-stressed and insulin-treated diabetic subjects. In non-hypoglycaemic subjects, there was a significant positive linear correlationship between urinary free cortisol and urinary creatinine excretion, but in the presence of hypoglycaemia, this relationship was lost. The highest mean urinary cortisol/creatinine ratio (UCCR) was found in subjects after an insulin tolerance test (ITT). The mean post-ITT UCCR was significantly greater than the mean for the pre-ITT samples. There was a significant negative correlation between capillary blood glucose levels at 03.00 and the UCCR of the overnight urine samples of insulin-treated diabetic subjects. We conclude that there is a definite increase in the UCCR after hypoglycaemia in subjects with adequate adrenocortical response to hypoglycaemia and that determination of the UCCR could be helpful in the detection of nocturnal hypoglycaemia.