Our diabetes team recently switched my three year old daughter, diagnosed three months ago, to Lantus with Humalog at every meal (and sometimes snacks), but she is going low four hours after her Humalog shots, which I think this is from the Lantus. However, the diabetes nurse denies this. My reasoning is that unless she eats, her numbers are always in the low 100s [mg/dl, 5.6 mmol/L]. Is it possible that even though the Lantus is “non-peaking”, her own body is still making insulin and therefore the Lantus is dropping her?

Using Lantus (insulin glargine) (or Ultralente) as the basal insulin in conjunction with Humalog, Novolog, or Regular as the bolus insulin is a very good way of giving insulin with the attempt to better mimic normal insulin production. In addition, it allows you to dose the short-acting bolus relative to the meals with carb counting.

The pre-meal glucose and the two-hour post-meal glucose should be pretty close to one another — within about 50 points. If the reading is lower, that suggests too much insulin (or over estimation of carbs). If the reading is higher, that suggests insufficient insulin (or under-estimation of carbs; i.e she gets more carbs than you thought).

Indeed low glucose readings may be concerning (especially if there are hypoglycemic seizures), but you also said that her readings are low ” in the low 100s [mg/dl, 5.6mmol/L]. That’s perfect! Remember that a normal glucose is about 60-120 mg/dl [3.3-6.7mmol/L], and even though our target for toddlers is often 80-200 mg/dl [4.1-11.1 mmol/L], I’m okay with normal!

DS