Increased heart rate changes are one initial sign for hypoglycemia episode.
Type 1 diabetes is an autoimmune disease where the pancreas does not produce insulin. Therefore, the primary treatment for this disease is insulin therapy. Exogenous insulin may induce hypoglycemia due to the fact that it is not subject to normal physiological feedback regulation.
Consequently, one of the most common adverse events seen in patients with type 1 diabetes is hypoglycemia. Severe hypoglycemia is considered a medical emergency and can lead to coma or death. On average, patients with type 1 diabetes have about two symptomatic hypoglycemia episodes each week. Early symptoms associated with hypoglycemia include: heart palpitation, confusion, dizziness, fatigue, pallor, anxiety, and diaphoresis. Detection of early symptoms is critical to avoid severe hypoglycemia. It has been noted that the common symptoms of hypoglycemia go unnoticed in patients with impaired awareness of hypoglycemia (IAH), therefore, they are six times more at risk of severe hypoglycemic events. Heart rate variability (HRV), secondary to hypoglycemia is due to the stimulation of the sympathetic nervous system and it is one of the measurable symptoms for early detection of hypoglycemia.
In this study, investigators assessed if changes in HRV, sensed by a wearable monitor, could be helpful for detecting hypoglycemia in patients with type 1 diabetes. A total of 29 participants included in this study were patients with type 1 diabetes with a minimum age of 18. All individuals were recruited from the Radboud University Medical Center outpatient clinic between June 2017 and February 2018. Any patients with a history of cardiac arrhythmias or who are on medications causing changes in heart rate were excluded from this study.
During this study, participants were asked to wear a HealthPatch, which has a single-lead electrocardiogram recording, on the chest for 5 consecutive days. Participants were continuously measured and then data was transferred via Bluetooth to an Apple, Inc. device. Awareness state was assessed using the Dutch modified version of the Clarke questionnaire, in which a score ≥3 classified as IAH (VitalConnect, San Jose, CA). Glucose was measured by fingerstick and any glucose ≤70 mg/dL [≤3.9 mmol/L] was categorized as mild hypoglycemia, and glucose <54 mg/dL was categorized as serious hypoglycemia. Any hypoglycemic event with the time of occurrence was recorded by the participants. Also, patients were asked to record the presence or absence of additional symptoms, and prior exercise (if applicable).
By using the paired sample t tests, the average changes in heart rate before hypoglycemia were compared to heart rate changes at the time of hypoglycemia. Results from data analysis showed that nine patients had IAH. There was a total of 66 hypoglycemic events, with a mean glucose level of 56 mg/dL recorded in this study. It was noted that 33% of those hypoglycemic events were considered serious.
Furthermore, typical HRV changes were observed in 36 (55%) events of the recorded hypoglycemia event and 18 events (27%) showed an atypical pattern. There were 10 (15%) unclassified events, and two (3%) without any changes in HRV.
HRV changes, associated with hypoglycemia, consisted of an increase in low and high frequency (LF:HF) changes and a decrease in standard differences of successive R-R intervals (RMSSD). The opposite effects were also seen with HRV changes due to hypoglycemia. Changes in HRV secondary to hypoglycemia were predominantly observed in patients with short diabetes duration and further influenced by gender, physical activity, and glucose peak level before and fall toward a hypoglycemic event. This study concluded that changes in HRV at the beginning of hypoglycemia could be detected by a wearable device to further prevent a severe hypoglycemic event.
Therefore, considering developments in wearables and data analytics, measuring real-time HRV could be very useful for early detection of hypoglycemia in people with diabetes, especially those with impaired awareness of hypoglycemia.
- On average, patients with type 1 diabetes have about two symptomatic hypoglycemia episodes each week.
- Common symptoms of hypoglycemia go unnoticed in patients with impaired awareness of hypoglycemia (IAH).
- Hypoglycemia causes early changes in HRV that can be detected by a wearable device. Measuring real-time HRV seems promising for early hypoglycemia detection.
References: Http://Www.historystudies.net/Dergi//Birinci-Dunya-Savasinda-Bir-Asayis-Sorunu-Sebinkarahisar-Ermeni-isyani20181092a4a8f.Pdf.” History Studies International Journal of History, vol. 10, no. 7, 2018, pp. 241–264., doi:10.9737/hist.2018.658.
Bekkink, Marleen Olde, et al. “Early Detection of Hypoglycemia in Type 1 Diabetes Using Heart Rate Variability Measured by a Wearable Device.” Diabetes Care, American Diabetes Association, 1 Apr. 2019, care.diabetesjournals.org/content/42/4/689.
Ghazal Blair, Pharm.D. Candidate 2019, LECOM School of Pharmacy