A Case of Insulin Edema Associated with Transient Bradycardia in Diabetic Ketoacidosis due to Type 1A Diabetes Mellitus

Abstract

A 37-year-old woman referred for hyperglycemia was found to have a plasma glucose level of 670 mg/dl, positive plasma ketone bodies, arterial gas indicating metabolic acidosis, and anti-GAD Ab of 96.0 U/ml, yielding a diagnosis of diabetic ketoacidosis (DKA) due to type 1A diabetes mellitus. Her DKA was normalized in 48 hours with intensive treatment. One week after multiple insulin injection were started, however, her weight rose from 49 kg to 55 kg associated with generalized edema. Her urinary sodium excretion on day 5 was less than 0.5 g/day and she developed bradycardia of 46/min and serum concentrations of epinephrine below 5 pg/ml and norepinephrine below 68 pg/ml. These changes disappeared following a low-sodium diet and furosemide administration. Edema was assumed to have been induced by the stimulatory effect of insulin on urinary sodium resorption in the renal distal tubules as indicated by others. We speculate that transient bradycardia may have been related to this edema, which suggests the need to clarify the role of bradycardia in the development of insulin edema.