I was curious as to why it is so important to test my daughters ketones when she is sick, even though her blood sugar levels are good. Doesn’t everyone get ketones when they are sick? What makes someone with diabetes different in that aspect? Basically, my understanding was that ketones were only dangerous when the blood sugar remains elevated for a short period of time. Could you please expand on this issue to clear up any misunderstandings I might have?

Ketones are physiologically produced even generally in small amounts when the body breaks down stored fat to get extra “fuel for energy.” People with diabetes can produce ketones if they go a long time without eating or don’t eat enough calories (as in fasting or dieting). Many young children who don’t have diabetes have ketones in their urine in the morning, as during the night when they are not eating, their body must break down stored fat to get “fuel.” The blood sugar is usually normal or can even be low if they are unable to get enough sugar from their stored fat and from stored sugar in the liver. As they get older, this generally ameliorates due to a better metabolic function of the liver.

Young children with diabetes can have ketones in the urine in the morning for the same reason I just described in children without diabetes. The production of ketones in this case is not related to the blood sugar. The most common reason for ketones to appear in the urine in children with diabetes is when there is not enough insulin. In this case, the blood sugar is high because the body can’t make enough insulin to use the sugar for energy and fat is broken down. Once ketones are produced, it may take 24 hours to clear them from the body, even if the blood sugar is returned to normal. Ketones can cause nausea, abdominal pain, and vomiting. Ketones can also be produced if the child is sick, say with a stomach virus, and the blood sugar goes high because the body can’t make extra insulin which is necessary during illness. If extra insulin is not given, ketoacidosis can develop rapidly. This is the reason why checking for ketones might be so important when your daughter is sick.

The third reason for ketones to appear is in response to a previous low blood sugar. It is well known that people with diabetes can sleep through a low blood sugar during the night and the blood sugar may come back to normal (or even go high) without treatment. This usually occurs because the body makes hormones like epinephrine which cause the body to release sugar which has been stored in the liver. These hormones also break down fat and produce ketones. The ketones may be present in the first morning urine even if the blood sugar is not high and may indicate an undiagnosed low blood sugar hours previously.

MS