Questions about prediabetes

Health Professional

Several questions have piled up about prediabetes (also spelled with a hyphen, like this: pre-diabetes), and I thought I'd tackle them all in once.

  • My fiance has the shakes when he does not eat until late afternoon. Is this a pre-warning sign of pre-diabetes?

Maybe. There are several logic steps that would be necessary to fulfill to link his "the shakes" symptoms to diabetes (or to the precursor of diabetes, prediabetes).

First, one might assume that his shakes that occur in the absence of food might be due to low blood glucose (hypoglycemia). The only way to tell if they were due to low glucose would be to get a blood glucose test done at that moment - which could be done with a home glucose meter. If the sugar level were consistently low (below 70 mg/dl) whenever a shaking episode occurs, then there would be a reasonable case to assume your fiancé has reactive (AKA postprandial) hypoglycemia. According to one authority, the definition for reactive hypoglycemia is "recurrent episodes of symptomatic hypoglycemia occurring within 4 hoursafter a high carbohydrate meal (or oral glucose load) in people who do not have diabetes."

And second, one would have to assume that his reactive hypoglycemia, if he has it, is a precursor for diabetes. This is sometimes true, but certainly is not always the case: there are other causes for reactive hypoglycemia (see  Postprandial Hypoglycemia (Reactive Hypoglycemia)  for more information).

Regardless of cause, people with reactive hypoglycemia often respond to reduced carbohydrate intake with frequent small meals. Such folks should be considered to have the potential to become diabetic, and advised to have periodic medical evaluations (such as A1C measurement).

  • What is considered pre-diabetic as far as a fasting blood sugar number?

Prediabetes is a medical situation that is diagnosed solely by the measurement of blood glucose: prediabetes means blood glucose levels (or A1C levels) that are higher than normal but not yet high enough to be diagnosed as diabetes. A normal fasting blood glucose level (fasting plasma glucose, to be technical) should be less than 100 mg/dl (5.6 mmol/L), and diabetes is defined as 126 mg/dl (7 mmol/L) or more. Anything in between (100-125 mg/dl, 5.6-6.9 mmol/L) would be prediabetic. BTW, if several FBG tests are done, and some are 126 or more, then I think most physicians would call the diagnosis diabetes even if some were normal or prediabetic.

A normal A1C should be less than 5.7, and diabetes is diagnosed if it's 6.5 or more. In between is prediabetes.

See How to Tell if You Have Diabetes or Prediabetes  for more information.

  • Should I take Actos for prediabetes?

In my opinion, no. There was a study about Actos (pioglitazone) that was sponsored by the manufacturer, that was published in the New England Journal of Medicine, Pioglitazone for Diabetes Prevention in Impaired Glucose Tolerance.  The study enrolled 602 patients with impaired glucose tolerance and BMI over 25, who were randomized to pioglitazone or placebo; however, median followup was short: less than 2.5 years. The authors concluded "As compared with placebo, pioglitazone reduced the risk of conversion of impaired glucose tolerance to type 2 diabetes mellitus by 72% but was associated with significant weight gain and edema." They found some additional good effects: Use of Actos resulted in "improved diastolic blood pressure, HDL cholesterol levels, and serum levels of alanine aminotranferase and aspartate aminotransferase, and it slowed progression of carotid intima-media thickening." But the main concern, to my thinking, is the cardiovascular side effects that were seen: there were more (26) cardiovascular adverse events in the Actos group than in the placebo group (23). This doesn't mean that Actos caused these events, but it definitely didn't prevent them.

If you want to take a drug for prediabetes, there simply isn't one: several have been studied -- among them metformin, Lantus (insulin glargine), and Actos/pioglitazone. But none have demonstrated the necessary efficacy and safety to persuade the FDA to approve them for use in prediabetes.

  • Are small amounts of dextrose OK for pre-diabetics?

Sure (in small amounts, as you say). Dextrose is a form of glucose, which is a form of sugar. And sugar is okay in moderate amounts for everyone. Of course, too much may contribute to obesity, and tooth decay. But the use of dextrose or other sugars in moderation is no big deal. Enjoy!