
April 29, 2008
Hyperglycemia and DKA
Question from Bedford, New Hampshire, USA:
Diagnosed at the age of five, my 13-year-old son has been on an insulin pump for about five years. In the past, he had an A1c that averaged between 6.5 and 7.0. He has maintained great control during the day while going through puberty, yet his numbers at night have been unbelievably high. This is definitely not an issue of omitted insulin or sneak eating since my husband and I still are very vigilant in overseeing insulin administration and, fortunately, our son is very compliant in his self management. The high blood sugars are also occurring around 2 to 3 a.m., long after his evening snack at 9:30 p.m. and bedtime around 10:30 p.m. We’ve been trying to monitor his blood sugars more closely at night to see when the spikes are occurring. He’ll be fine at 11 p.m., midnight, 1 a.m. and sometimes 2 a.m. (sleeping through all the finger sticks) and then will rise to the 300s after that until around 6 a.m.. We’ve increased his basal rates during the 2 a.m. to 6 a.m. period by a full unit of insulin each hour, changed his nighttime correction factor for this time period from 1:100 to 1:60 and have even resorted, on occasion, to giving shots rather than relying on the pump to make sure that it’s not a pump malfunction. We’ve only had one scare where he was producing ketones (we check blood ketones simultaneously with blood sugars when he’s really high) and that was last week when he spiked to 560 mg/dl [31.1. mmol/L]. What else can we do? My husband and I are more than a little sleep deprived and are getting really concerned about our son’s health. Is this just a result of growth hormones? He has grown about 6 inches in the last year.
Answer:
You may have left out a very important bit of information. You indicated that “in the past,” your son’s A1c values have been between 6.5 and 7%. But, what have the values been lately? If his A1c values are still as excellent as this, then I would (literally) not lose too much sleep with all the nighttime checks. A good A1c, despite some nocturnal elevated glucose values, may help you see the forest from the trees.
Having said that, you have had eight years of diabetes experience, but maybe you are not familiar with what is commonly called the “Dawn Phenomenon.” This is a NATURAL process, in part through normal hormonal secretory patterns, that lead to higher glucose values in the hours around awakening. This is partly why FASTING glucose is used to help make a diagnosis of diabetes.
Your observation of your child’s growth and your question about “growth hormones” is close to the mark. There is an increase in the adrenal glands’ productions of cortisol and the pituitary gland’s production of growth hormone associated with the natural rhythm of the body clock. For those who awaken in the morning (as opposed to those who awaken to work the graveyard shifts), this “dawn phenomenon” helps to stoke the metabolic fire to get your day going and by increasing available glucose for fuel. During puberty, the associated growth spurt is well-documented to be associated with increased secretion of growth hormone – not just in the morning but overall higher 24 hour levels. Furthermore, puberty obviously is associated with increased levels of testosterone in boys (and estrogen in girls) and these pubertal steroids antagonize the effects of insulin.
With an insulin pump, you can easily raise the basal rates during these morning times when you find the higher glucose. But, I would advise that you do so only under the supervision or blessing of your child’s own pediatric endocrinologist. You want to avoid serious over-insulinization that could lead to serious hypoglycemia.
DS