Biography: Aldasouqi is professor of medicine and chief of the endocrinology division at Michigan State University College of Human Medicine in East Lansing.
February 20, 2018
3 min read

BLOG: A word of caution to insulin pump users to ‘spring forward’

Biography: Aldasouqi is professor of medicine and chief of the endocrinology division at Michigan State University College of Human Medicine in East Lansing.
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It’s happening again — the daylight saving time spring ritual. This year the daylight saving time change will occur on March 11. The time change begins at 2 a.m. and will result in the day beginning 1 hour earlier the following Monday.

Depending on where you live in the United States this may create a sudden change in people’s routines — a sudden change in the time of waking up, preparing the kids for school or leaving home for work.

As readers of my blog may have noticed, I have been dedicating two posts annually for the occasions of daylight saving time changes, in the spring and fall. To avoid repeating myself, I would refer the readers to my prior blogs: A reminder to insulin pump users — reset the clock for daylight saving time and Heathrow Airport, insulin pumps and daylight saving time — What do they have in common?

In these posts, I alluded to the health hazards that may result, especially following the spring daylight saving time change. These risks include the risk for increased incidence of myocardial infarction on the Monday following the change, as reported in the medical literature. The explanation is that there is increased stress associated with the lost hour of sleep with resultant sudden change in circadian rhythm. People in cold regions may also be vulnerable to colder temperatures going to work earlier, unprepared.

Within my specialty, I have alluded to an overlooked glitch in insulin pumps’ internal clocks. The internal clocks of most commercially available insulin pumps are not GPS-enabled nor do they have built-in mechanisms to automatically adjust for the daylight saving time change. Since our modern life’s electronic gadgets are all GPS-enabled or have built-in time change mechanisms, many of us do not pay attention to devices that still require manual adjustment. Some patients with diabetes may not remember to make the daylight saving time change on their insulin pump’s internal time setting on time or they may never make the change.

I have explained in prior blog posts that this 1-hour difference may potentially cause errors in insulin doses and I have detailed scientific discussions in a review article published in the Journal of Diabetes Science and Technology in 2014.


Despite these efforts in the quest of educating the public, including patients on insulin pumps and their care providers, there are still patients who continue to forget to adjust their insulin pump’s time setting. A recent example is that of a patient of mine, who was recently seen about 2 months after the fall’s daylight saving time change which had occurred on the first Sunday of last November. The patient’s pump clock was actually set to 1 hour later. Luckily, no significant errors occurred from the 1-hour time difference. Her basal settings for basal rates had trivial differences and she had a single insulin-to-carbohydrate ratio. As I explained in previous posts and in the review article, significant errors may potentially occur in other circumstances.

A related issue, which was also emphasized in my prior publications is the issue of potential errors in the a.m. to p.m. setting. If an insulin pump’s clock is set up incorrectly between a.m. and p.m., overlooked erroneous doses for day and night may be administered.

In a prior post I mentioned the incident of air traffic shutdown at the United Kingdom’s Heathrow Airport due to an a.m. to p.m. glitch in air traffic control’s time setting.

Another issue is the issue of some states who wrote legislative bills to try to eliminate the daylight saving time change. A couple of years ago, such a bill was not approved in Michigan but most recently, Florida is now trying to do the same. According to the Orlando Sentinel, this issue has been one of heated debate.

So, as Floridians debate the daylight saving time ritual, this is a call to all clinicians who manage diabetes to always check the time setting of their patient’s pumps on each visit. Routine reminders to patients to prepare them for the biannual daylight saving time change is also recommended. Also, this is a call to all patients using insulin pumps — and their caregivers for pediatric patients — to keep the daylight saving time change always in mind.