While You’re Sleeping . . . Your A1c May Go For A Ride

Even if your blood glucose level is in target range when you go to bed and when you get up, it could go travelling while you’re asleep. And that nighttime variation could make your A1c goals harder to reach.

We read about this in a post by Ginger Vieira on diabetesdaily.com.

(As newcomers to the website and blog scene, we’re educating ourselves—and learning a lot—by visiting the many good diabetes blogs out there; diabetesdaily.com is one of them.)

Ginger’s post tells why you should check your nighttime blood glucose levels (if you don’t have a continuous glucose monitor), and suggests what to keep track of and ways to adjust your eating habits, if you need to.


(While you’re at the site, we suggest you sign up for the weekly “best of diabetes daily” emails and check out the posts. They illustrate how widely patients vary in their symptoms of diabetes and in their responses to food and medications. The posts also reveal how knowledgeable and helpful some patients are, sharing experiences and offering support.)

A Walk on the . . . Wild Side?

Getting back to blood glucose levels—when they go travelling in the wee hours, they could even take someone on a different ride—to the police station.

We sat in on a session led by a registered dietitian, certified diabetes educator (RD, CDE). She fielded a question from a newly diagnosed type 2 patient—a sleepwalker—who would arise in a trance in the middle of the night and head for the kitchen. His wife recently found him at 3:30 a.m. eating a sandwich, roaming around the front lawn—naked.

What, he asked, should he do?

The dietitian didn’t lose a beat. “Wear pajamas!”

The next step: he should set his alarm that night for 2 a.m., check his blood glucose level, and eat something appropriate. To be followed the next day by possible adjustments in medication, food intake, and testing times, and perhaps a conversation with his doctor.

Bottom line: The A1c test measures the average blood glucose level 24 hours a day, over the previous two to three months. If daytime blood glucose readings are within normal range, indicating good daytime control, but blood glucose levels are consistently elevated during the night, the A1c reading—indicating overall average control—is likely to be high. The high reading can come as a surprise to patients who haven’t been checking their nighttime blood glucose levels.