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Background: Hybrid closed-loop insulin therapy has shown promise for management of type 1 diabetes during pregnancy; however, its efficacy is unclear., Methods: In this multicenter, controlled trial, we randomly assigned pregnant women with type 1 diabetes and a glycated hemoglobin level of at least 6.5% at nine sites in the United Kingdom to receive standard insulin therapy or hybrid closed-loop therapy, with both groups using continuous glucose monitoring. The primary outcome was the percentage of time in the pregnancy-specific target glucose range (63 to 140 mg per deciliter [3.5 to 7.8 mmol per liter]) as measured by continuous glucose monitoring from 16 weeks' gestation until delivery. Analyses were performed according to the intention-to-treat principle. Key secondary outcomes were the percentage of time spent in a hyperglycemic state (glucose level >140 mg per deciliter), overnight time in the target range, the glycated hemoglobin level, and safety events., Results: A total of 124 participants with a mean (±SD) age of 31.1±5.3 years and a mean baseline glycated hemoglobin level of 7.7±1.2% underwent randomization. The mean percentage of time that the maternal glucose level was in the target range was 68.2±10.5% in the closed-loop group and 55.6±12.5% in the standard-care group (mean adjusted difference, 10.5 percentage points; 95% confidence interval [CI], 7.0 to 14.0; P<0.001). Results for the secondary outcomes were consistent with those of the primary outcome; participants in the closed-loop group spent less time in a hyperglycemic state than those in the standard-care group (difference, -10.2 percentage points; 95% CI, -13.8 to -6.6); had more overnight time in the target range (difference, 12.3 percentage points; 95% CI, 8.3 to 16.2), and had lower glycated hemoglobin levels (difference, -0.31 percentage points; 95% CI, -0.50 to -0.12). Little time was spent in a hypoglycemic state. No unanticipated safety problems associated with the use of closed-loop therapy during pregnancy occurred (6 instances of severe hypoglycemia, vs. 5 in the standard-care group; 1 instance of diabetic ketoacidosis in each group; and 12 device-related adverse events in the closed-loop group, 7 related to closed-loop therapy)., Conclusions: Hybrid closed-loop therapy significantly improved maternal glycemic control during pregnancy complicated by type 1 diabetes. (Funded by the Efficacy and Mechanism Evaluation Program; AiDAPT ISRCTN Registry number, ISRCTN56898625.)., (Copyright © 2023 Massachusetts Medical Society.)

Objective: To determine if temporal glucose profiles differed between 1 ) women who were randomized to real-time continuous glucose monitoring (RT-CGM) or self-monitored blood glucose (SMBG), 2 ) women who used insulin pumps or multiple daily insulin injections (MDIs), and 3 ) women whose infants were born large for gestational age (LGA) or not, by assessing CGM data obtained from the Continuous Glucose Monitoring in Women With Type 1 Diabetes in Pregnancy Trial (CONCEPTT)., Research Design and Methods: Standard summary metrics and functional data analysis (FDA) were applied to CGM data from the CONCEPTT trial (RT-CGM, n = 100; SMBG, n = 100) taken at baseline and at 24- and 34-weeks' gestation. Multivariable regression analysis determined if temporal differences in 24-h glucose profiles occurred between comparators in each of the three groups., Results: FDA revealed that women using RT-CGM had significantly lower glucose (0.4-0.8 mmol/L [7-14 mg/dL]) for 7 h/day (0800 h to 1200 h and 1600 h to 1900 h) compared with those with SMBG. Women using pumps had significantly higher glucose (0.4-0.9 mmol/L [7-16 mg/dL]) for 12 h/day (0300 h to 0600 h, 1300 h to 1800 h, and 2030 h to 0030 h) at 24 weeks with no difference at 34 weeks compared with MDI. Women who had an LGA infant ran a significantly higher glucose by 0.4-0.7 mmol/L (7-13 mg/dL) for 4.5 h/day at baseline, by 0.4-0.9 mmol/L (7-16 mg/dL) for 16 h/day at 24 weeks, and by 0.4-0.7 mmol/L (7-13 mg/dL) for 14 h/day at 34 weeks., Conclusions: FDA of temporal glucose profiles gives important information about differences in glucose control and its timing, which are undetectable by standard summary metrics. Women using RT-CGM were able to achieve better daytime glucose control, reducing fetal exposure to maternal glucose., (© 2020 by the American Diabetes Association.)

Objective: Despite advances in technology, optimal glucose control remains elusive and neonatal complications remain ubiquitous in type 1 diabetes (T1D) pregnancy. Our aim was to examine the safety, efficacy, and longer-term feasibility of day-and-night closed-loop insulin delivery., Research Design and Methods: We recruited 16 pregnant women (mean [SD]: age 32.8 [5.0] years, T1D duration 19.4 [10.2] years, HbA 1c 8.0% [1.1], and BMI 26.6 [4.4] kg/m 2 ) to an open-label, randomized, crossover trial. Participants completed 28 days of closed-loop and sensor-augmented pump (SAP) insulin delivery separated by a washout period. Afterward, participants could continue to use the closed-loop system up to 6 weeks postpartum. The primary end point was the proportion of time with glucose levels within the target range (63-140 mg/dL)., Results: The proportion of time with glucose levels within target was comparable during closed-loop and SAP insulin delivery (62.3 vs. 60.1% [95% CI -4.1 to 8.3]; P = 0.47). Mean glucose and time spent hyperglycemic >140 mg/dL also did not differ (131.4 vs. 131.4 mg/dL [ P = 0.85] and 36.6 vs. 36.1% [ P = 0.86], respectively). During closed-loop, fewer hypoglycemic episodes occurred (median 8 [range 1-17] vs. 12.5 [1-53] over 28 days; P = 0.04) and less time at <63 mg/dL (1.6 vs. 2.7%; P = 0.02). Hypoglycemia <50 mg/dL (0.24 vs. 0.47%; P = 0.03) and low blood glucose index (1.0 vs. 1.4; P = 0.01) were lower. Less nocturnal hypoglycemia (2300-0700 h) during closed-loop therapy (1.1 vs. 2.7%; P = 0.008) and a trend toward higher overnight time in target (67.7 vs. 60.6%; P = 0.06) were found., Conclusions: Closed-loop insulin delivery was associated with comparable glucose control and significantly less hypoglycemia than SAP therapy. Larger, longer-duration multicenter trials are now indicated to determine clinical efficacy of closed-loop insulin delivery in T1D pregnancy and the impact on neonatal outcomes., (© 2018 by the American Diabetes Association.)

Background: In patients with type 1 diabetes who are not pregnant, closed-loop (automated) insulin delivery can provide better glycemic control than sensor-augmented pump therapy, but data are lacking on the efficacy, safety, and feasibility of closed-loop therapy during pregnancy., Methods: We performed an open-label, randomized, crossover study comparing overnight closed-loop therapy with sensor-augmented pump therapy, followed by a continuation phase in which the closed-loop system was used day and night. Sixteen pregnant women with type 1 diabetes completed 4 weeks of closed-loop pump therapy (intervention) and sensor-augmented pump therapy (control) in random order. During the continuation phase, 14 of the participants used the closed-loop system day and night until delivery. The primary outcome was the percentage of time that overnight glucose levels were within the target range (63 to 140 mg per deciliter [3.5 to 7.8 mmol per liter])., Results: The percentage of time that overnight glucose levels were in the target range was higher during closed-loop therapy than during control therapy (74.7% vs. 59.5%; absolute difference, 15.2 percentage points; 95% confidence interval, 6.1 to 24.2; P=0.002). The overnight mean glucose level was lower during closed-loop therapy than during control therapy (119 vs. 133 mg per deciliter [6.6 vs. 7.4 mmol per liter], P=0.009). There were no significant differences between closed-loop and control therapy in the percentage of time in which glucose levels were below the target range (1.3% and 1.9%, respectively; P=0.28), in insulin doses, or in adverse-event rates. During the continuation phase (up to 14.6 additional weeks, including antenatal hospitalizations, labor, and delivery), glucose levels were in the target range 68.7% of the time; the mean glucose level was 126 mg per deciliter (7.0 mmol per liter). No episodes of severe hypoglycemia requiring third-party assistance occurred during either phase., Conclusions: Overnight closed-loop therapy resulted in better glucose control than sensor-augmented pump therapy in pregnant women with type 1 diabetes. Women receiving day-and-night closed-loop therapy maintained glycemic control during a high proportion of the time in a period that encompassed antenatal hospital admission, labor, and delivery. (Funded by the National Institute for Health Research and others; Current Controlled Trials number, ISRCTN71510001.).

Purpose of Review: Accumulating evidence supports a role for the circadian clock in the development of metabolic disease. We discuss the influence of the circadian clock on glucose homeostasis, intermediary factors in this relationship, and potential therapies for the prevention or attenuation of metabolic disease associated with circadian misalignment., Recent Findings: Murine studies with tissue-specific deletion of core clock genes in key metabolic tissues confirm a mechanistic relationship between the circadian clock and the development of metabolic disease. Circadian misalignment increases insulin resistance and decreases pancreatic function. Clock gene polymorphisms or altered expression of clock genes induced by circadian misalignment appear to play a role in the development of obesity and diabetes in humans. Circadian disruption caused by exposure to light at night is associated with lower nocturnal melatonin, which in turn seems to affect glucose metabolism. Potential therapies for circadian misalignment include entraining the central pacemaker with timed light exposure and/or melatonin and restricting food intake to the biological day., Summary: Completing the understanding of how genetic and environmental factors influence the circadian clock and the effect these have on human circadian metabolic physiology and disease will allow us to develop therapies for treating and preventing associated metabolic disease.

It has been shown that sustained insulin infusion causes an increase in sympathetic vasoconstrictor discharge but, despite this, also causes peripheral vasodilatation. The present study was designed to determine in healthy subjects the effect of ingestion of a carbohydrate meal, with its attendant physiological insulinaemia, on vascular resistance in and sympathetic vasoconstrictor discharge to the same vascular bed, and the relationship between these parameters. Fifteen healthy subjects were studied for 2 h following ingestion of a carbohydrate meal. Calf vascular resistance was measured by venous occlusion plethysmography, and muscle sympathetic nerve activity was assessed by peroneal microneurography. Five of the subjects also ingested water on a separate occasion, as a control. Following the carbohydrate meal, the serum insulin concentration increased to 588+/-72 pmol/l. This was associated with a 47% increase in skeletal muscle blood flow (P<0.001), a 39% fall in vascular resistance (P<0.001) and a 57% increase in sympathetic activity (P<0.001). There was a significant correlation between the increase in insulin and the changes in blood flow, vascular resistance and sympathetic activity. In conclusion, we have shown that ingestion of a carbohydrate meal, with its attendant physiological insulinaemia, was associated with overriding skeletal muscle vasodilatation, despite an increase in sympathetic vasoconstrictor discharge to the same vascular bed. These mechanisms may be important in ensuring optimal glucose uptake and maintenance of blood pressure postprandially.

Poor glycaemic control is found in diabetes, one of the most common, serious, non-communicable diseases worldwide. Trials suggest a relationship between glycaemic control and measures of sleep including duration and quality of sleep. Currently, the relationship between specific sleep stages (including slow-wave sleep (SWS), a sleep stage mainly found early in the night and linked to restorative functioning) and glycaemic control remains unclear. This systematic review aimed to synthesise the evidence of the effectiveness of specific sleep stage manipulation on measures of glycaemic control (insulin resistance, fasting and post-prandial glucose and insulin). Public databases (eg psychINFO, MEDLINE, Academic Search Complete, psychARTICLES, OpenDissertations, Scopus and Cochrane library) were searched for randomised controlled trials. Trials were included if they involved direct manipulation of SWS and/or rapid eye-movement sleep to explore the impact on measures of glycaemic control (insulin resistance, fasting and post-prandial glucose and insulin). Eight trials met the eligibility criteria, with four providing data for inclusion in one of the three meta-analyses. Insulin resistance was significantly higher in the SWS disruption when compared to the normal sleep condition, (p = 0.02). No significant differences were found for measures of fasting or post-prandial glucose or insulin. Risk of bias was considered low for performance bias, detection bias and incomplete outcome data, with unclear selection bias. This is an emerging area of research and this review provides preliminary findings and recommendations for future research around optimising sleep stage disruption (to further explore mechanisms) and sleep stage enhancement techniques (to explore potential interventions). [ABSTRACT FROM AUTHOR]