My mother-in- law who has diabetes and other medical problems such as Alzheimer’s disease, gets no exercise at all and eats very little. She takes a shot in the morning and pills at night. Lately, her sugar has been running at times as low as 44 mg/dl [2.4 mmol/L], she gets confused and won’t talk, her arms start jerking, and she just lays there. My brother-in-law, who gives her shots and medicine, said the doctor told him he wanted her sugar to stay at 70 mg/dl [3.9 mmol/L], but my mother also has diabetes and her doctor says it shouldn’t be under 120-130 mg/dl [6.7-7.2 mmol/L]. What should the normal range be for someone who already has diabetes?

Normal fasting glucose levels are about 70-110 mg/dl [3.9-6.1 mmol/L] for most people. For many people with diabetes, the goal is to keep the glucose levels as normal as possible, although this is often difficult to do, especially without causing too many low glucose levels.

In older people, especially someone with Alzheimer’s disease who may not recognize signs of low glucose levels and may not be able to ask for help when their glucose level is low or know what to do, most doctors would recommend that the glucose levels be kept a little higher, so as to avoid hypoglycemia.

It sounds as if your mother-in-law is having too many hypoglycemic reactions, and these could be dangerous, due to possible loss of consciousness or confusion. I would recommend that the goal for her glucose levels be no lower than 100-120 mg/dl [5.6-6.7 mmol/L]. This should be discussed with her health care team and likely her medications should be decreased.

ML

[Editor’s comment: I agree completely with Dr. Luidens — low blood sugars can be extremely dangerous, especially if she were to fall while confused and break a bone. And the reason for recommending very tight control is mainly to prevent complications years in the future — which may not be a reasonable goal for some people with other chronic and progressive illnesses.

WWQ]