Continuous Glucose Monitoring in the Intensive Care Unit Following Total Pancreatectomy with Islet Autotransplantation in Children: Establishing Accuracy of the Dexcom G6 Model

Dynamic associations between glucose and ecological momentary cognition in Type 1 Diabetes

Type 1 diabetes (T1D) is a chronic condition characterized by glucose fluctuations. Laboratory studies suggest that cognition is reduced when glucose is very low (hypoglycemia) and very high (hyperglycemia). Until recently, technological limitations prevented researchers from understanding how naturally-occurring glucose fluctuations impact cognitive fluctuations. This study leveraged advances in continuous glucose monitoring (CGM) and cognitive ecological momentary assessment (EMA) to characterize dynamic, within-person associations between glucose and cognition in naturalistic environments. Using CGM and EMA, we obtained intensive longitudinal measurements of glucose and cognition (processing speed, sustained attention) in 200 adults with T1D. First, we used hierarchical Bayesian modeling to estimate dynamic, within-person associations between glucose and cognition. Consistent with laboratory studies, we hypothesized that cognitive performance would be reduced at low and high glucose, reflecting cognitive vulnerability to glucose fluctuations. Second, we used data-driven lasso regression to identify clinical characteristics that predicted individual differences in cognitive vulnerability to glucose fluctuations. Large glucose fluctuations were associated with slower and less accurate processing speed, although slight glucose elevations (relative to person-level means) were associated with faster processing speed. Glucose fluctuations were not related to sustained attention. Seven clinical characteristics predicted individual differences in cognitive vulnerability to glucose fluctuations: age, time in hypoglycemia, lifetime severe hypoglycemic events, microvascular complications, glucose variability, fatigue, and neck circumference. Results establish the impact of glucose on processing speed in naturalistic environments, suggest that minimizing glucose fluctuations is important for optimizing processing speed, and identify several clinical characteristics that may exacerbate cognitive vulnerability to glucose fluctuations.

Total pancreatectomy with islet autotransplantation reduces opioid use and improves nutritional support in children with debilitating pancreatitis

BACKGROUND

Chronic pancreatitis (CP) can result in opioid dependence and nutritional challenges in children. Total pancreatectomy with islet autotransplantation (TPIAT) is a viable surgical option in appropriately selected patients. We examined differences between children who met criteria for TPIAT versus those who did not and continued with non-operative management.

METHODS

Retrospective observational cohort study of patients evaluated for TPIAT between August 2014 and July 2020 was performed. Cohort-based analyses between TPIAT and non-TPIAT groups were performed.

RESULTS

Analyses included 121 patients, 69 of whom underwent TPIAT. Demographics, genetic risk factors, and anatomic variants did not differ between groups. TPIAT patients were more likely to have CP (88% vs 71%; p = 0.02), had higher median number of endoscopic retrograde cholangiopancreatography procedures (2.0 vs 1.0; p = 0.0001), and had higher likelihood of opioid use (61% vs 42%; p = 0.04) and nutritional supplementation (23% vs 4%; p = 0.004), compared to non-TPIAT. At 6 months post-TPIAT, patients had lower use of any analgesic pain medications (39% vs 73%; p = 0.0002) and lower use of opioids (9% vs 39%; p = 0.0006), compared to non-TPIAT patients at 6 months after evaluation. At 6 months post-TPIAT, rate of exclusively oral nutrition increased from 77% to 86%, and total parenteral nutrition use decreased from 13% to 0% (p = 0.02).

CONCLUSIONS

In children referred for TPIAT evaluation, there is greater burden of disease in those selected for operation, compared to patients who do not undergo operation. TPIAT achieves lower analgesic pain medication use compared to continuation with non-TPIAT management and achieves freedom from nutritional supplementation. Level of evidence: Retrospective comparative study, Level III.

Metabolic Outcomes in Pediatric Patients One-Year Post-Total Pancreatectomy with Islet Autotransplantation after Early Pump Initiation

We previously published that insulin pump initiation immediately after IV insulin therapy was associated with improved post-surgical glycemic outcomes compared to multiple daily injections (MDI) in pediatric patients following a total pancreatectomy with islet autotransplantation (TPIAT). We investigated metabolic outcomes of this population at one-year post-TPIAT to assess if the improved outcomes in the early pump group were sustained over time. We retrospectively reviewed 40 patients post-TPIAT previously studied at 10-days post-surgery (15 used MDI and 25 used pump therapy immediately post-ICU, and all were discharged on pump therapy). Data analyzed included: demographics, islet equivalents per kilogram (IEQ/kg) transplanted, exogenous insulin use, and baseline vs. one-year (via mixed meal testing) HbA1c, fasting glucose, insulinogenic index, and the area under the curve (AUC) for insulin and c-peptide. More patients were off insulin at one year in the early pump group compared to the MDI group (45% vs. 13%, p = 0.07). Of all patients off insulin, 100% of the early pump users weaned off by six months post-TPIAT compared to 30% of the MDI users. Two known variables associated with favorable insulin outcomes, lower age and higher IEQ/kg, were not significantly different between groups. Fasting glucose was lower in the early pump group compared to the MDI group (median 97 vs. 122 mg/dL, p = 0.003), while AUC c-peptide was greater in early pump users at one-year post-TPIAT but did not reach significance (median 57.0 vs. 50.3 ng/mL × minutes, p = 0.14). Other metabolic outcomes did not differ between groups. Despite lower median age and higher IEQ/kg in the MDI group, the early pump group had a lower fasting glucose. Younger TPIAT age (p = 0.02) and early pump users (p = 0.04) were significantly associated with insulin independence at one year. This study was limited by sample size. Early pump use may have long-term benefits in post-TPIAT endogenous insulin secretion.

Accuracy of Real Time Continuous Glucose Monitoring during Different Liquid Solution Challenges in Healthy Adults: A Randomized Controlled Cross-Over Trial

Continuous glucose monitoring (CGM) represents an integral of modern diabetes management, however, there is still a lack of sensor performance data when rapidly consuming different liquids and thus changing total body water. 18 healthy adults (ten females, age: 23.1 ± 1.8 years, BMI 22.2 ± 2.1 kg·m−2) performed four trial visits consisting of oral ingestion (12 mL per kg body mass) of either a 0.9% sodium chloride, 5% glucose or Ringer’s solution and a control visit, in which no liquid was administered (control). Sensor glucose levels (Dexcom G6, Dexcom Inc., San Diego, CA, USA) were obtained at rest and in 10-min intervals for a period of 120 min after solution consumption and compared against reference capillary blood glucose measurements. The overall MedARD [IQR] was 7.1% [3.3−10.8]; during control 5.9% [2.7−10.8], sodium chloride 5.0% [2.7−10.2], 5% glucose 11.0% [5.3−21.6] and Ringer’s 7.5% [3.1−13.2] (p < 0.0001). The overall bias [95% LoA] was 4.3 mg·dL−1 [−19 to 28]; during control 3.9 mg·dL−1 [−11 to 18], sodium chloride 4.8 mg·dL−1 [−9 to 19], 5% glucose 3.6 mg·dL−1 [−33 to 41] and Ringer’s solution 4.9 mg·dL−1 [−13 to 23]. The Dexcom G6 CGM system detects glucose with very good accuracy during liquid solution challenges in normoglycemic individuals, however, our data suggest that in people without diabetes, sensor performance is influenced by different solutions.

Predictors of Glycemic Outcomes at 1 Year Following Pediatric Total Pancreatectomy With Islet Autotransplantation

OBJECTIVE

Total pancreatectomy with islet autotransplantation (TPIAT) is indicated to alleviate debilitating pancreas-related pain and mitigate diabetes in patients with acute recurrent and chronic pancreatitis when medical/endoscopic therapies fail. Our aim was to evaluate predictors of insulin requirement at 1 year following TPIAT in a cohort of children.

RESEARCH DESIGN AND METHODS

This was a review of 43 pediatric patients followed after TPIAT for 1 year or longer. Primary outcome was insulin use at 1 year, categorized as follows: insulin independent, low insulin requirement (<0.5 units/kg/day), or high insulin requirement (≥0.5 units/kg/day).

RESULTS

At 1 year after TPIAT, 12 of 41 (29%) patients were insulin independent and 21 of 41 (51%) had low and 8 of 41 (20%) had high insulin requirement. Insulin-independent patients were younger than those with low and high insulin requirement (median age 8.2 vs. 14.6 vs. 13.1 years, respectively; P = 0.03). Patients with insulin independence had a higher number of transplanted islet equivalents (IEQ) per kilogram body weight (P = 0.03) and smaller body surface area (P = 0.02), compared with those with insulin dependence. Preoperative exocrine insufficiency was associated with high insulin requirement (P = 0.03). Higher peak C-peptide measured by stimulated mixed-meal tolerance testing (MMTT) at 3 and 6 months post-TPIAT was predictive of lower insulin requirement at 1 year (P = 0.006 and 0.03, respectively).

CONCLUSIONS

We conclude that insulin independence following pediatric TPIAT is multifactorial and associated with younger age, higher IEQ per kilogram body weight transplanted, and smaller body surface area at time of operation. Higher peak C-peptide measured by MMTT following TPIAT confers a higher likelihood of low insulin requirement.