Medications used for the treatment of diabetes can precipitate an abnormally low blood sugar level during sleep. This adverse side effect, termed nocturnal hypoglycemia or a "nighttime low," occurs primarily with insulin therapy. It may occur less commonly among people taking a sulfonylurea. Severe nocturnal hypoglycemia can be potentially life-threatening.
Night Sweats
Hypoglycemia may trigger drenching sweats, says the American Diabetes Association. A nervous system reaction to the fall in blood sugar triggers this symptom. Night sweats, however, are not specific to low blood sugar. In an article on night sweats published in "American Family Physician," Dr. Anthony Viera and colleagues note that more than 25 different causes of night sweats. As such, blood sugar testing remains necessary in establishing hypoglycemia as the cause of this symptom.
Nightmares and Vivid Dreams
In a 2007 article on nocturnal hypoglycemia published in the journal "PLoS Medicine," Drs. Ilan Gabriely and Harry Shamoon reported that vivid dreams and nightmares can be symptoms of low nocturnal blood sugar. Recognizing nightmares as a symptom of nocturnal hypoglycemia proves important for parents of diabetic children, who may not recognize hypoglycemic symptoms on their own.
Awakening and Confusion
Some people with nocturnal hypoglycemia awaken during the episode. Information provided by the University of Iowa Hospitals and Clinics notes that mental symptoms such as confusion, mental fogginess or anxiety may occur upon awakening during a hypoglycemia episode. Importantly, the normal mechanisms that cause awakening with hypoglycemia may be impaired among those with type I diabetes mellitus. In a 2007 research article published in "PLoS Medicine," Dr. Bernd Schultes and colleagues found that people with type I diabetes were less likely to awaken at a set level of hypoglycemia compared to non-diabetics. The authors noted that the failure to awaken correlated with a weak nervous system response to the hypoglycemic episode, compared to a strong response observed among non-diabetics.
Morning Headache
The Joslin Diabetes Center reports that morning headaches commonly occur after nocturnal hypoglycemic episodes. This symptom may serve as an important warning signal among those who do not awaken during nocturnal hypoglycemic episodes. If morning headaches occur regularly, setting an alarm for nighttime glucose testing may help determine whether nocturnal hypoglycemic episodes are occurring.
Seizures and Coma
Information provided by the University of Iowa Hospital and Clinics cautions that severe nocturnal hypoglycemia may lead to seizure or coma. The potential for a life-threatening nocturnal hypoglycemic episode poses a significant risk, especially for type I diabetics. During sleep, a hypoglycemic episode can easily progress to a state of unconsciousness without intervention. Consistency in activity, diet and medication regimens can help reduce the risk of severe nocturnal hypoglycemia.
References
- American Diabetes Association Youth Zone: Hypoglycemia
- Joslin Diabetes Center: Avoiding Nighttime Lows
- Joslin Diabetes Center: Sleep Problems and Diabetes
- University of Iowa Hospitals and Clinics: Hypoglycemia
- American Family Physician; Diagnosing Night Sweats; Anthony J. Viera, M.D., et al.; March 2003
