The effects of acute psychological stress, heart rate variability (HRV), an indicator of autonomic function and glycemic variability (GV) have not been extensively researched in type 1 diabetes (T1D). The aim of this study is to explore the effect of acute psychosocial stress on HRV and GV in people with T1D. Methods: Eleven participants with T1D (33.00 ± 11.25 years) participated in the study. To assess acute mental stress, the subjects 1) participated in the Trier Social Stress Test (TSST); and 2) played competitive video games (Nintendo Switch™). The TSST followed standardized procedures whereby stress was induced asking participants to provide a job talk and arithmetic in front of two judges. Participants played the Mario Kart to go-kart races (10 minutes) and rotated their controllers to untangle the Treasure Chest (10 minutes). Resting HRV and GV were obtained. The subjects wore a continuous glucose monitor and a Zephyr Bioharness™ to record GV and HRV, respectively. Nonparametric, paired samples T-tests were conducted using SPSS 24. Results: During TSST, there were significant differences between the resting and TSST testing period in the sympathetic nervous sympathetic nervous system index (.57 ± 1.33 vs. 1.36 ± 1.40; z = -2.845, respectively; p <.01; and stress index (8.17 ± 3.69 vs. 10.27 ± 5.69; z = -2.578, respectively; p <.05). When subjects were playing video games, there were significant differences in the parasympathetic nervous sympathetic nervous system index (-.09 ± 1.75 vs. -.87 ± 1.05; z = -2.134, respectively; p <.05) compared to a resting period. However, there were no significant differences in GV compared to a resting period in during TSST and playing video game. Conclusion: This study suggests that the TSST induced stress in people with T1D, increased sympathetic activity; however, the TSST did not change glycemic variability. Playing competitive video game did not appear to neither induces stress nor affected glycemic variability. The competitive video game did not cause stress compared to TSST. Disclosure M. Park: None. Y. Song: None. M. Chu: None. M. Sevil: None. N. Hobbs: None. L. Sharp: None. A. Cinar: Research Support; Self; Dexcom, Inc., JDRF. Stock/Shareholder; Self; Dexcom, Inc., Eli Lilly and Company, Insulet Corporation, Medtronic, Novo Nordisk A/S, Tandem Diabetes Care. L.T. Quinn: None. Funding JDRF

People with type 1 diabetes (T1D) have an increased risk for autonomic dysfunction and those with poorly controlled blood glucose levels have an increased risk for cardiovascular disease. The purpose of this study was to determine heart rate variability (HRV) and glucose variability (GV) parameters in less than optimally controlled patients (Group 2: A1C ≥ 7.0%, n = 6]) compared to well-controlled patients (Group 1: A1C ≤ 6.9% [n = 7]) during steady state treadmill exercise took and rest. Methods: Thirteen T1D participants, (32.42 ± 10.46 years), performed steady state treadmill exercise (40% VO2Peak) for 30 minutes. Prior to exercise, participants rested for 30-minutes for determination of resting HRV and GV. Participants wore continuous glucose monitors and a Zephyr Bioharness™ to determine GV and HRV, respectively. Nonparametric, paired samples T-tests were conducted using SPSS 24. Results: In group 2, there were significant differences between the resting period and treadmill exercise in the (1) root mean score of successive differences (RMSSD) (27.71 ± 13.43 vs. 8.01 ± 3.90; z = -2.201, respectively; p <.05); (2) standard deviation of RR intervals (SDNN) (36.54 ± 16.04 vs. 11.68 ± 6.19; z = -2.201, respectively; p <.05); and (3) the stress index (11.17 ± 5.48 vs. 23.07 ± 6.31; z = -2.201, respectively; p <.05). However, during treadmill exercise, there were no significant differences in GV, compared to a resting period. In group 1, there were no significant differences in HRV, during treadmill exercise compared to the resting period. However, there were significant differences in GV (.26 ± .18 vs. .54 ± .38; z = -2.197, respectively; p <.05)., between resting and exercise period. Conclusion: This study suggests that during steady state aerobic exercise, people with poorer glucose control exhibit a pattern of metabolic inflexibility; however, HRV decreased with steady state exercise in both groups suggesting that exercise training may help to normalize HRV in patients with poorly controlled glucose levels. Disclosure M. Park: None. M. Chu: None. Y. Song: None. M. Sevil: None. A. Cinar: Research Support; Self; Dexcom, Inc., JDRF. Stock/Shareholder; Self; Dexcom, Inc., Eli Lilly and Company, Insulet Corporation, Medtronic, Novo Nordisk A/S, Tandem Diabetes Care. L.T. Quinn: None. U.G. Bronas: None. Funding JDRF

Background: Theoretically, women who have had GDM are likely to have increased stress levels following pregnancy related to parental stress exacerbated by concerns about personal health (e.g., development of T2DM). Such stress may negatively impact sleep, however, the relationship between parenting stress and sleep in women who have had GDM has not been well investigated. Therefore, the purpose of the study was to explore the correlations between sleep and parenting stress in people who have had GDM. Methods: Twenty-six woman (ages: 34.22 ± 3.51 years; ethnicity: African American [38.46%], Hispanic [30.77%], Caucasian [19.23%], and Asian [11.54%]; A1C: 5.78 ± .98 %; BMI: 36.28 ± 10.70; age of child from GDM pregnancy: 6.07 ± 3.95 months; number of children: range1-6; months of postpartum: 6.06 ± 3.96) who had GDM on the previous pregnancy completed self-reported questionnaires. These included Parenting Stress Index (PSI-4, SF), PROMIS Global Health-Physical (v.1.2;2a), PROMIS Fatigue (v.1.0;8a), PROMIS Sleep Disturbance (v.1.0;8b), and PROMIS Sleep-Related Impairment (v.1.0;8a). The Spearman’s correlation was used to analyze data using STATA 17.0. Results: The mean total score on the Parenting Stress Index was positively correlated with PROMIS Fatigue (Spearman’s r = 0.61, p < .01); PROMIS Sleep Disturbance (r = 0.61, p < .001); and PROMIS Sleep-Related Impairment (r= 0.57, p < .001). On the other hand, the mean total score on the Parenting Stress Index was negatively correlated with PROMIS Global Health-Physical (r = -0.58, p < .01), and was not correlated with A1C and BMI. Conclusion: In this glucose intolerant group of women with previous GDM, parenting stress was correlated with fatigue alone with sleep disturbances and impairments. In addition, parenting stress was negatively correlated with individuals’ assessment of their health. Finding suggested that it is necessary to explore the associations between parenting stress, sleep, and glucose metabolism in women who have had GDM. Disclosure M. Park: None. Y. Song: None. M. Chu: None. L. T. Quinn: None.

Nineteen people with T1D (10 male, 9 female. Age: 31 +/- 9 yrs, A1c: 6.6 +/- 0.8 and duration of diabetes: 19 +/- 11 years) had their sleep monitored with an EEG-based device (Zmachine Insight+) for a total of 154 nights. Their blood glucose levels (BGL) were measured with a CGM. From the CGM data, the participant’s average BGL, standard deviation of BGL, coefficient of variation of BGL, Percent Time in Range (70-180 mg/dL), Percent Time Above Range (>180 mg/dL), and Percent Time Below Range (<70 mg/dL) was calculated for each overnight period. A t-Test was used to determine if there was a difference between characteristics in the participants’ overnight BGL based on different sleep quality metrics. Participants who had sleep efficiency scores > 85% had less variable overnight BGL determined by the standard deviation and coefficient of variation of CGM (p = 0.0013 and 0.017). Participants who had higher average overnight BGL and more fluctuations, as determined by standard deviation and coefficient of variation, in their BGL (p = 0.017, 0.000004, and 0.0004) spent more time awake overnight. Those who have lower average overnight BGL spent more time in Deep and REM sleep stages (p = 0.044 and 0.0043). From these findings, we can conclude that overnight BGL has a significant impact on sleep quality in people with T1D. Based on previous research, this reduction in sleep quality may negatively impact daytime control. Disclosure R. Brandt: None. M. Park: None. L.T. Quinn: None. M. Chu: None. Y. Song: None. B.M. Burton-Freeman: None. A. Cinar: Research Support; Self; Dexcom, Inc., JDRF. Stock/Shareholder; Self; Dexcom, Inc., Eli Lilly and Company, Insulet Corporation, Medtronic, Novo Nordisk A/S, Tandem Diabetes Care. Funding JDRF (A18-0036-001)

People with type 1 diabetes (T1D) have personal strategies for maintaining euglycemia while exercising which generally serves them well during training. Their strategy often yields wildly differing results during a competition. The influence of competition stress (notably, epinephrine causing prompt elevations in glucose) and high-intensity and/or long-duration efforts can yield dysglycemia. Two different studies were conducted to observe this phenomenon. In a small study of subjects with T1D completing athletic competitions, perceived stress level as reported by the individual is insufficient for determination impact upon glycemia. An elevated heart rate during the competition over what was observed at the same running pace in training was a better indicator of an increase in glycemia. To recreate an athletic stress scenario in a clinical setting, 13 subjects with T1D completed a low intensity treadmill protocol for 3 sessions: non-stress, verbally reported mental math with an audience, and stressful video games to observe the influence on glycemia and heart rate. The treadmill protocol, prior meal, and insulin doses were matched for each individual for the 3 sessions. When compared to the non-stress treadmill session, an elevated average heart rate was observed in 10 of the 13 video game sessions and an elevated average glucose was observed in 9 of the 13 video game sessions. In the mental math sessions, an average heart rate elevated heart rate was observed in 6 of the 13 sessions with 7 of 13 having a higher average glucose compared to the non-stress session. While individual response to acute stress yields a high degree of intersubject variability, the video game sessions may more closely match the competition stress experienced and physiological response to stress observed during an athletic competition. The cause of the stressor may be critical in detection of stress and predicting glycemic response for the management of T1D. Disclosure N. Hobbs: None. M. Park: None. M. Chu: None. Y. Song: None. L.T. Quinn: None. M. Sevil: None. A. Cinar: Research Support; Self; Dexcom, Inc., JDRF. Stock/Shareholder; Self; Dexcom, Inc., Eli Lilly and Company, Insulet Corporation, Medtronic, Novo Nordisk A/S, Tandem Diabetes Care. Funding JDRF (A18-0036-001); National Institutes of Health (DP3DK101075, F31DK116524)