Silent Deaths in Diabetes

There has been many instances of unexpected deaths in the case of patients with Type-1 diabetes. In typical instances of this syndrome,

1. Patients are found dead in bed, after being in rather good health the day before,
2. More often than not, the cause of death is not established and autopsy is not very informative.

What is it?

This syndrome or rather most of the instances of its reported occurring is characterized by one fact. That it happened with young people, with no history of diabetic complications, and in particular no autonomic dysfunction. Obviously, it is not a syndrome in the strict sense of the term. It is a type of death in diabetic patients, which remains mysterious after routine examinations, and which may or may not have a single underlying cause.

Is it rampant?

According to the British Diabetic Association reports, there were nearly 22 dead in bed instances in one year. There were no signs of alcohol or other intoxication, and autopsies were normal except for signs of cerebral hemorrhages in one case and bite marks in the mouth of another case.

How does it happen?

First it has to be made clear that discussing the causes of an unexplained phenomenon would be purely an exercise in speculation. The fact remains, even if it is conceded that the speculation is an educated and intelligent one. The most reasonable and believable hypothesis is, that hypoglycemia (the extreme low levels of blood glucose), plays a significant role. Hypoglycemia could be particularly harmful when coupled with inadequate hormonal counter-regulation.

The problem with considering hypoglycemia, as a cause, is that there are recorded instances of hypoglycemic brain damage and death. And these instances are completely different from those of dead- in- bed (DiB) syndrome. There have been cases where patients brought unconscious to the hospital with hypoglycemia never regained consciousness.

Another hitch in assuming hypoglycemia, as a cause, is that nighttime (nocturnal) hypoglycemia is a common phenomenon in Type-1 diabetes, but a mortal eventuality is extremely rare. In the quest to solve the mystery behind the DiB syndrome of diabetic patients, there could be important lessons to be learnt from other disorders. An evaluation of cerebral factors versus cardiac factors is particularly insightful in this regard. From such a perspective it can be seen that sudden death is associated with physical activity and epilepsy. But existing data from those conditions are not helpful in explaining the DiB syndrome.

There is a general assumption that DiB is occurring mostly in patients who use insulin pens. It has been speculated that patients with pen injectors for short-acting pre-meal bolus injection and bedtime intermediate insulin might use the wrong pen injector at bedtime and go to sleep without realizing their mistake. This could be a potential risk for the occurrence of severe nocturnal hypoglycemia. So far there is no data available to support this notion.

There has been a controversy wherein the allegation was that the DiB was caused by human insulin use. There is no convincing scientific evidence in favor of the contention that human insulin leads to loss of hypoglycemia warning symptoms. What could be an important debating point, however, is the shifting trend toward a common use of multiple daily doses of rapid-acting insulin. It is now well established that efforts to normalize blood glucose and decrease HbA1c carry an increased risk of hypoglycemia, often during the night. Studies have suggested that such treatment carries with it a three-fold increase in risk of hypoglycemia, especially nocturnal hypoglycemia.

How to fight it?

Adolescents are often plagued by the doubt: Will I die if my blood sugar falls during the night? Many years ago, most diabetologists would have said, definitely no. With present day knowledge nobody would want to commit on that. The practical suggestion that one might get is to concentrate on preventive measures.

Patients having frequent hypoglycemic reactions, with or without nocturnal hypoglycemia, need to be extremely cautious. One should be cautious in recommending near-normal blood glucose and HbA1c in these patients, particularly if they sleep alone. In physically active patients special care has to be taken to counter the problem of post-exercise hypoglycemia.