June 12, 2003
Question from Bethel, Connecticut, USA:
If a person with diabetes has nocturnal hypoglycemia (in particular hypos are not severe enough to wake that person or induce a seizure but still well below target), would this cause a lesser quality of sleep leaving the person more tired than would be expected after a night's sleep? Though the situations are different, I think about a person with sleep apnea who is perpetually tired. Could low blood glucoses cause the same disruptions to one's stages of sleep?
This has been a complicated issue to study and understandably there are not too many reports. (See Matyka KA, Crawford C, Wiggs L, Dunger DB, Stores G. Alterations in sleep physiology in young children with insulin-dependent diabetes mellitus: relationship to nocturnal hypoglycemia. J Pediatr. 2000 Aug;137(2):233-8. ) On balance, the evidence seems to be that sleep is more interrupted in diabetes and that the counterregulatory response to hypoglycemia is diminished, but I don’t think there is any real support for linking lassitude in the daytime to subclinical nocturnal hypoglycemia.
From a practical point of view, you might want to talk to your child’s doctor about switching to Lantus as a basal insulin with one of the short-acting insulin analogs (Humalog or NovoLog) after meals which minimises nocturnal hypoglycemia. Obviously, there are other causes for being perpetually tired which may need to be looked into.