A Call From Health Care Providers and a Patient to End Daylight Savings Time Free

Daylight savings time (DST) changes occur twice a year, in March and November. In the United States, all states follow the DST changes except for Hawaii and Arizona (excluding the Navajo Nation) (1), which eliminated DST through state legislation decades ago. Other states have attempted to eliminate DST through legislation but have failed. Outside of the United States, a similar attempt has been made by some northern European countries, which have petitioned the European Parliament to eliminate DST (2).

Although primarily a political debate, the issue of DST has recently become a health concern because of disruptions it causes in circadian rhythm and aberrant sleep duration (2). Several health risks have been attributed to DST changes. Available studies have found significant increases in the risks related to DST, including the risk for major vascular events, although related studies of myocardial infarction and cerebrovascular accidents have been conflicting (2–4). Other health risks have been reported, however, including fatigue, headache, loss of attention and alertness, reduced motivation, motor vehicle and workplace injuries, missed medical appointments, and general mortality (2). In addition, our group at Michigan State University (MSU) published a review article in the Journal of Diabetes Science and Technology in 2014 about another DST-related health repercussion: the potential risk of glitches in insulin pumps attributed to DST (5).

In this commentary, we wish to focus on the effects of DST on insulin pumps in patients with diabetes. Although most technological devices (e.g., cell phones) adjust for DST changes automatically, to the best of our knowledge, insulin pumps do not have this capability. For accurate and timely delivery of insulin via an insulin pump, it is prudent that the time setting of the pump be the same as the ambient time (synchronization). Incorrect time settings in insulin pumps may result in incorrect insulin delivery if different basal and/or bolus settings are used. This time mismatch may result in potential harm to insulin pump users, resulting in hyperglycemia or hypoglycemia (5).

Since our group became aware of this glitch in insulin pumps more than 10 years ago, we have been educating our patients about this health concern. Also, our health organization, MSU Health Care, routinely posts a message on its Facebook page to remind patients with diabetes who use insulin pumps to remember to make the DST change (6) (Figure 1).

To reach out to larger audiences for the purpose of public health awareness, one of us (S.A.) has used all available vehicles and venues, including presenting scientific abstracts (case reports) at national medical meetings, as well as writing about this issue in his blog in the Endocrine Today magazine on the Healio website (7). Locally, he has also been reaching out to local TV news channels to spread this message on evening news broadcasts.

Despite our efforts to educate our patients about DST glitches, we have detected incorrect time settings in some of our patients’ insulin pumps after the DST changes in the fall and spring and occasional cases of incorrect insulin dosing, resulting in hyperglycemia or hypoglycemia.

In fact, what prompted us to write this article was a recent DST time glitch that affected one of us (K.S.), a nurse practitioner in our practice (the MSU endocrinology clinic) who has type 1 diabetes and uses an insulin pump. She volunteered to share her personal experience with the public. K.S. made an error while updating her insulin pump time settings for the latest DST change on 10 March 2024. She mistakenly reversed the a.m. and p.m. settings. Several hours later, she noticed that her blood glucose levels during the day became higher than usual, and she was surprised that her pump showed Sleep Mode during the day. Her insulin settings were different for daytime and nighttime. With the reversed insulin delivery dose settings, she developed hyperglycemia because she was receiving less insulin during the day than usual. Fortunately, K.S. discovered the glitch before going to sleep and escaped a potential occurrence of nocturnal hypoglycemia.

We share the personal experience of K.S. here and elsewhere for the purpose of public health education and awareness regarding this critical issue related to DST and insulin pump function. In addition to this article, we reached out to a local TV station (WILX Lansing), and the story aired on the evening news broadcast (8). In that interview, it was hypothesized that if this type of glitch can affect health care providers, occurrences may be going unreported in more patients who use insulin pumps.

In addition to K.S.’s case, we have previously encountered several DST-related glitches involving patients using insulin pumps, some of which caused hyperglycemia or hypoglycemia. We have not reported these cases in the literature, nor have we undertaken clinical studies to address the prevalence of this problem. We acknowledge that such published evidence is desirable and would strengthen our call to eliminate DST changes.

Furthermore, although we focus here on DST-related glitches in insulin pump time settings, we acknowledge that such glitches can occur unrelated to DST changes, such as when traveling across time zones. However, we believe that patients using insulin pumps would be more aware of the ambient time while traveling and perhaps less likely to forget to update their insulin pump time settings than if they are around DST changes. However, without evidence, this hypothesis remains speculative.

It is prudent to note that such time-related glitches in insulin pumps collectively stem from an inherent fault in the manufacturing of insulin pumps. We believe that insulin pump manufacturers are obligated to equip insulin pumps with the function of automated updating of time, including automatic updates for DST changes and time zone changes and safeguards against a.m./p.m. reversals. We believe that global positioning system connectivity would ensure accurate time updates at all times and in all places.

Finally, although our call to eliminate DST change stems from health risks as detailed above, we acknowledge that this is a politically charged issue, and it continues to be debated nationally and at the state level. The original premise of DST was based on the rationale of energy savings and thus economic benefits. However, this rationale has been refuted (9).

In conclusion, and on behalf of our patients and all patients who use insulin pumps and struggle with the hassles of DST adjustments, we hope this commentary will achieve the goal of encouraging the public to support proposed legislation at the state and national levels to abolish DST nationwide.