Suspecting unwitnessed hypoglycaemia

Hypoglycaemic coma can present with acute neurological dysfunction mimicking stroke. It may be masked by normoglycaemia due to physiological compensatory mechanisms (Somogyi phenomenon). Specific MR brain scan changes should alert the clinician to consider this alternative to stroke in the acute setting in patients with a history of recurrent hypoglycaemia, even when the blood glucose is not low at presentation. Rapid identification and treatment of hypoglycaemia may confer a good prognosis with radiological resolution.

Comparison of continuous and intermittent glucose monitoring systems in a dog with diabetic ketoacidosis: a case report

A Miniature schnauzer (12 years old, neutered male) was referred for lethargy, anorexia, and oral bleeding. On initial evaluation, severe hyperglycaemia (blood glucose concentration of 34.9 mmol/l), ketonuria, systemic inflammation (fever, panting, left-shift neutrophilia, and a high C-reactive protein level of 980.97 nmol/l, abnormal pancreatic lipase immunoreactivity, and periodontitis were found. With consideration of possible insulin resistance, blood glucose (BG) levels were monitored using a portable glucose meter (q 1–3 h) and a continuous glucose monitoring system (CGMS) for 72 h (three consecutive trials); intensive insulin therapy was initiated using regular insulin (2.2 IU/kg intravenously). The insulin doses needed, based on the nadir, peak, and duration of insulin action from a traditional intermittent glucose curve were higher than those based on the CGMS results. Meanwhile, transient hyperglycaemic and hypoglycaemic periods, occurring between the intermittent measurements, were easily identified with the CGMS. Therefore, insulin resistance and the Somogyi phenomenon are less likely to occur with use of the CGMS than with intermittent BG measurements. By comparing data from a CGMS to those from an intermittent portable BG measurement system, this case report emphasises the importance and usefulness of a CGMS.

In search of the Somogyi effect

The Somogyi phenomenon or rebound hyperglycaemia is known as the counterregulatory response to asymptomatic nocturnal hypoglycaemia; the Somogyi phenomenon occurs with high fasting blood glucose levels and hyperglycaemia the following morning. Most published trials, however, do not agree with this theory. Although data from some experimental studies may suggest a pathophysiological link. Perhaps, the differences in research results are caused by the evolution of blood glucose monitoring methods. Nevertheless, it cannot be excluded that the results of Michael Somogyi’s studies were misunderstood.