Effect of combined aerobic-resistance training and subsequent detraining on brain-derived neurotrophic factor (BDNF) and depression in women with type 2 diabetes mellitus: A randomized controlled trial.

AIMS: In this study, we assessed the effects of a 12-week combined aerobic-resistance training and subsequent detraining on Beck Depression Inventory (BDI) score and mediating role of BDNF and also investigated whether exercise-induced alterations are maintained following a short period of detraining in women with type 2 diabetes (T2D). MATERIALS AND METHODS: Thirty-four women with T2D were randomly assigned to experimental or control group (age: 60.6 ± 6.3, body mass index (BMI): 30.2 ± 1.3 kg/m2 , HbA1c: 8.09 ± 0.73%). The exercise training comprised of combined aerobic-resistance programme (50%-70% heart rate reserve for aerobic exercise, and 50%-70% 1 repetition maximum for resistance exercise, respectively) performed three sessions per week over 12 weeks. The intervention period was followed by an 8-week detraining period. Data were collected at baseline and also following exercise intervention and detraining. Data were analysed by linear mixed model at p < 0.05. RESULTS: After 12 weeks of combined exercise training and 8 weeks of detraining, there was a significant difference in BDNF (0.08; 95% confidence interval [CI] = 0.07-0.10; p = 0.001), fasting blood glucose (FBG) (-45.41; CI = -50.83, -39.98; p = 0.001), insulin (-6.47; CI = -7.04, -5.9; p = 0.001), HOMA-IR (-3.76; CI = -4.07, -3.45; p = 0.001) and BDI score (-17.17; CI = -20.29, -14.05; p = 0.001) between the experimental and control group. Multiple mediation analysis indicated that BDNF seems to have a mediating role in exercise-induced improvement of depression (p = 0.04). After the detraining period, BDI score remained unchanged and it showed a significant increase compared to before the start of training (p = 0.001). CONCLUSIONS: It may be concluded that exercise training improves depression that is likely to be explained by increased BDNF concentration in TD2. In spite of decreased BDNF concentration following an 8-week detraining, depression score was maintained.

Effects of light-intensity physical activity on cardiometabolic parameters in young adults with overweight and obesity: The SED-ACT randomized controlled crossover trial.

AIMS: To investigate how a change in body position with light-intensity physical activity (PA) 'snacks' (LIPAS, alternate sitting and standing, walking or standing continuously) compared with uninterrupted prolonged sitting affects glucose metabolism and heart rate variability (HRV) parameters in young adults with overweight and obesity. MATERIALS AND METHODS: We conducted a four-arm randomized controlled crossover trial. The following conditions were tested during an 8-h simulated workday: uninterrupted prolonged sitting (SIT), alternate sitting and standing (SIT-STAND; 2.5 h total), continuous standing (STAND), and continuous walking (1.0 mph; WALK). The primary outcome was to investigate how a change in body position (alternate sitting and standing, walking or standing continuously) compared with uninterrupted sitting affects mean 8-h glucose metabolism. Secondary outcomes included the effects on 2-h postprandial glucose concentrations, as well as on 8-h/24-h heart rate and HRV parameters, in the respective study arms. Capillary blood samples were drawn from an hyperemised earlobe in the fasted state and once every hour during each trial intervention by puncturing the earlobe with a lancet and collecting 20 µL of blood (Biosen S-Line Lab+; EKF diagnostics, Barleben, Germany). HRV was assessed for 24 h including the 8-h intervention phase, and a home phase by means of a Holter electrocardiogram. All participants received the same standardized non-relativised breakfast and lunch during the four trial visits. RESULTS: Seventeen individuals (eight women, mean age 23.4 ± 3.3 years, body mass index 29.7 ± 3.8 kg/m2, glycated haemoglobin level 34.8 ± 3.1 mmol/mol [5.4 ± 0.3%], body fat 31.8 ± 8.2%) completed all four trial arms. Compared with SIT (89.4 ± 6.8 mg/dL), 8-h mean glucose was lower in all other conditions (p < 0.05) and this was statistically significant compared with WALK (86.3 ± 5.2 mg/dL; p = 0.034). Two-hour postprandial glucose after breakfast was approximately 7% lower for WALK compared with SIT (p = 0.002). Furthermore, significant time × condition effects on HRV parameters favouring light-intensity walking were observed (p < 0.001). CONCLUSIONS: Replacement and interruption of prolonged sitting with light-intensity walking showed a significant blood glucose-lowering effect and improved HRV during an 8-h work environment in young adults with overweight and obesity.

Impact of a 4-week intensive track and field training intervention on glycaemia in adolescents with type 1 diabetes: The ChilDFiT1 study.

AIM: To investigate the safety and efficacy of track and field training compared with intensification of insulin treatment only in adolescents with type 1 diabetes (T1D). MATERIALS AND METHODS: Eighteen adolescents (seven females) with T1D were included (age 15.1 ± 1.1 years, HbA1c 7.3% ± 1.0% [56.3 ± 10.9 mmol/mol]). After a 4-week observational control phase, participants were randomized to either stand-alone intensive glycaemic management (IT; telemedicine or on-site visits, three times/week) or additionally performed track and field exercise (EX; three 60-minute sessions/week) for 4 weeks. Glycaemia was assessed via continuous glucose monitoring during observational control and intervention phases. RESULTS: Time in range (70-180 mg/dL; 3.9-10.0 mmol/L) significantly improved from the observational control phase to the exercise intervention phase in EX (69% ± 13% vs. 72% ± 11%, P = .049), but not in IT (59% ± 22% vs. 62% ± 16%, P = .399). Time below range 1 (54-69 mg/dL; < 3.9 mmol/L) improved in IT (3.1% ± 1.9% vs. 2.0% ± 0.8%, P = .017) and remained stable in EX (2.0% ± 1.7 vs. 1.9% ± 1.1%, P = .999). The EX group's HbA1c ameliorated preintervention to postintervention (mean difference: ΔHbA1c -0.19% ± 0.17%, P = .042), which was not seen within the IT group (ΔHbA1c -0.16% ± 0.37%, P = .40). Glucose standard deviation was reduced significantly in EX (55 ± 11 vs. 51 ± 10 mg/dL [3.1 ± 0.6 vs. 2.8 ± 0.6 mmol/L], P = .011), but not in IT (70 ± 24 vs. 63 ± 18 mg/dL [3.9 ± 1.3 vs. 3.5 ± 1.0 mmol/L], P = .186). CONCLUSION: Track and field training combined with intensive glycaemic management improved glycaemia in adolescents with T1D, which was not observed in the non-exercise group.

Leptin Signaling Could Mediate Hippocampal Decumulation of Beta-Amyloid and Tau Induced by High-Intensity Interval Training in Rats with Type 2 Diabetes.

Leptin (LEP) can cross the blood-brain barrier and facilitate cross-talk between the adipose tissue and central nerve system (CNS). This study aimed to investigate the effect of 8-week high-intensity interval training (HIIT) on the LEP signaling in the hippocampus of rats with type 2 diabetes. 20 rats were randomly divided into four groups: (i) control (Con), (ii) type 2 diabetes (T2D), (iii) exercise (EX), and (iv) type 2 diabetes + exercise (T2D + EX). The rats in the T2D and T2D + EX were fed a high-fat diet for two months, then a single dose of STZ (35 mg/kg) was injected to induce diabetes. The EX and T2D + EX groups performed 4-10 intervals of treadmill running at 80-100% of Vmax. Serum and hippocampal levels of LEP as well as hippocampal levels of LEP receptors (LEP-R), Janus kinase 2 (JAK-2), signal transducer and activator of transcription 3 (STAT-3), activated protein kinase (AMP-K), proxy zoster receptor α (PGC-1α), beta-secretase 1 (BACE1), Beta-Amyloid (Aß), Phosphoinositide 3-kinases (PI3K), protein kinase B (AKT), mammalian target of rapamycin (mTOR), Glycogen Synthase Kinase 3 Beta (GSK3ß), and hyperphosphorylated tau proteins (TAU) were measured. One-way ONOVA and Tukey post-hoc tests were used to analyze the data. Serum and hippocampal levels of LEP as well as hippocampal levels of LEP-R, JAK-2, STAT-3, AMP-K, PGC1α, PI3K, AKT, and mTOR were increased while hippocampal levels of BACE1, GSK3B, TAU, and Aß were decreased in T2D + EX compared with T2D group. Serum LEP and hippocampal levels of LEP, LEP-R, JAK-2, STAT-3, AMP-K, PGC1α, PI3K, AKT, and mTOR were decreased. Conversely hippocampal levels of BACE1, GSK3B, TAU, and Aß were increased in T2D group compared with CON group. HIIT could improve LEP signaling in the hippocampus of rats with type 2 diabetes and decrease the accumulation of Tau and Aß, which may reduce the risk of memory impairments.

High Intensity Interval Training can Ameliorate Hypothalamic Appetite Regulation in Male Rats with Type 2 Diabetes: The Role of Leptin.

Disruption of leptin (LEP) signaling in the hypothalamus caused by type 2 diabetes (T2D) can impair appetite regulation. The aim of this study was to investigate whether the improvement in appetite regulation induced by high-intensity interval training (HIIT) in rats with T2D can be mediated by LEP signaling. In this study, 20 male Wister rats were randomly assigned to one of four groups: CO (non-type 2 diabetes control), T2D (type 2 diabetes), EX (non-type 2 diabetes exercise), and T2D + EX (type 2 diabetes + exercise).To induce T2D, a combination of a high-fat diet for 2 months and a single dose of streptozotocin (35 mg/kg) was administered. Rats in the EX and T2D + EX groups performed 4-10 intervals of treadmill running at 80-100% of their maximum velocity (Vmax). Homeostatic Model Assessment for Insulin Resistance (HOMA-IR), serum levels of insulin (INS) and LEP (LEPS) as well as hypothalamic expression of LEP receptors (LEP-R), Janus kinase 2 (JAK-2), signal transducer and activator of transcription 3 (STAT-3), neuropeptide Y (NPY), agouti-related protein (AGRP), pro-opiomelanocortin cocaine (POMC), amphetamine-related transcript (CART), suppressor of cytokine signaling (SOCS3), forkhead box protein O1 (FOXO1) were assessed. ANOVA and Tukey post hoc tests were used to compare the results between the groups. The levels of LEPS and INS, as well as the levels of LEP-R, JAK-2, STAT-3, POMC, and CART in the hypothalamus were found to be higher in the T2D + EX group compared to the T2D group. On the other hand, the levels of HOMA-IR, NPY, AGRP, SOCS3, and FOXO1 were lower in the T2D + EX group compared to the T2D group (P < 0.0001). The findings of this study suggest that HIIT may improve appetite regulation in rats with T2D, and LEP signaling may play a crucial role in this improvement. Graphical abstract (leptin signaling in the hypothalamus), Leptin (LEP), Leptin receptor (LEP-R), Janus kinase 2 (JAK2), Signal transducer and activator of transcription 3 (STAT3), expressing Neuropeptide Y (NPY), Agouti-related protein (AGRP), anorexigenic neurons (expressing pro-opiomelanocortin cocaine (POMC), Amphetamine-related transcript (CART), suppressor of cytokine signaling (SOCS3), forkhead box protein O1 (FOXO1).

Blood glucose response to running or cycling in individuals with type 1 diabetes: A systematic review and meta-analysis.

AIMS: The aim of this systematic review and meta-analysis was to assess how running and cycling influence the magnitude of blood glucose (BG) excursions in individuals with type 1 diabetes. METHODS: A systematic literature search was conducted in EMBASE, PubMed, Cochrane Central Register of Controlled Trials, and ISI Web of Knowledge for publications from January 1950 until February 2021. Parameters included for analysis were population (adults and adolescents), exercise type, intensity, duration and insulin preparation. The meta-analysis was performed to estimate the pooled mean with a 95% confidence interval (CI) of delta BG levels. In addition, sub-group and meta-regression analyses were performed to assess the influence of these parameters on delta BG. RESULTS: The database search identified 3192 articles of which 69 articles were included in the meta-analysis. Due to crossover designs within articles, 151 different results were included for analysis. Data from 1901 exercise tests of individuals with type 1 diabetes with a mean age of 29 ± 4 years were included. Overall, exercise tests BG decreased by -3.1 mmol/L [-3.4; -2.8] within a mean duration of 46 ± 21 min. The pooled mean decrease in BG for running was -4.1 mmol/L [-4.7; -2.4], whilst the pooled mean decrease in BG for cycling was -2.7 mmol/L [-3.0; -2.4] (p < 0.0001). Overall results can be found in Table S2. CONCLUSIONS: Running led to a larger decrease in BG in comparison to cycling. Active individuals with type 1 diabetes should be aware that current recommendations for glycaemic management need to be more specific to the mode of exercise.

Impact of severe hypoglycaemia requiring hospitalization on mortality in people with type 1 diabetes: A national retrospective observational cohort study.

AIMS: To assess if the risk of all-cause mortality increases in people with type 1 diabetes (T1D) with increasing number of severe hypoglycaemia episodes requiring hospitalization. MATERIALS AND METHODS: We conducted a national retrospective observational cohort study in people with T1D (diagnosed between 2000 and 2018). Clinical, comorbidity and demographic variables were assessed for impact on mortality for people with no, one, two and three or more episodes of severe hypoglycaemia requiring hospitalization. The time to death (all-cause mortality) from the timepoint of the last episode of severe hypoglycaemia was modelled using a parametric survival model. RESULTS: A total of 8224 people had a T1D diagnosis in Wales during the study period. The mortality rate (95% confidence interval [CI]) was 6.9 (6.1-7.8) deaths/ 1000 person-years (crude) and 15.31 (13.3-17.63) deaths/ 1000 person-years (age-adjusted) for those with no occurrence of severe hypoglycaemia requiring hospitalization. For those with one episode of severe hypoglycaemia requiring hospitalization the mortality rate (95% CI) was 24.9 (21.0-29.6; crude) and 53.8 (44.6-64.7) deaths/ 1000 person-years (age-adjusted), for those with two episodes of severe hypoglycaemia requiring hospitalization it was 28.0 (23.1-34.0; crude) and 72.8 (59.2-89.5) deaths/ 1000 person-years (age-adjusted), and for those with three or more episodes of severe hypoglycaemia requiring hospitalization it was 33.5 (30.0-37.3; crude) and 86.3 (71.7-103.9) deaths/ 1000 person years (age-adjusted; P < 0.001). A parametric survival model showed that having two episodes of severe hypoglycaemia requiring hospitalization was the strongest predictor for time to death (accelerated failure time coefficient 0.073 [95% CI 0.009-0.565]), followed by having one episode of severe hypoglycaemia requiring hospitalization (0.126 [0.036-0.438]) and age at most recent episode of severe hypoglycaemia requiring hospitalization (0.917 [0.885-0.951]). CONCLUSIONS: The strongest predictor for time to death was having two or more episodes of severe hypoglycaemia requiring hospitalization.

Comparative Analysis of Predictive Interstitial Glucose Level Classification Models.

BACKGROUND: New methods of continuous glucose monitoring (CGM) provide real-time alerts for hypoglycemia, hyperglycemia, and rapid fluctuations of glucose levels, thereby improving glycemic control, which is especially crucial during meals and physical activity. However, complex CGM systems pose challenges for individuals with diabetes and healthcare professionals, particularly when interpreting rapid glucose level changes, dealing with sensor delays (approximately a 10 min difference between interstitial and plasma glucose readings), and addressing potential malfunctions. The development of advanced predictive glucose level classification models becomes imperative for optimizing insulin dosing and managing daily activities. METHODS: The aim of this study was to investigate the efficacy of three different predictive models for the glucose level classification: (1) an autoregressive integrated moving average model (ARIMA), (2) logistic regression, and (3) long short-term memory networks (LSTM). The performance of these models was evaluated in predicting hypoglycemia (<70 mg/dL), euglycemia (70-180 mg/dL), and hyperglycemia (>180 mg/dL) classes 15 min and 1 h ahead. More specifically, the confusion matrices were obtained and metrics such as precision, recall, and accuracy were computed for each model at each predictive horizon. RESULTS: As expected, ARIMA underperformed the other models in predicting hyper- and hypoglycemia classes for both the 15 min and 1 h horizons. For the 15 min forecast horizon, the performance of logistic regression was the highest of all the models for all glycemia classes, with recall rates of 96% for hyper, 91% for norm, and 98% for hypoglycemia. For the 1 h forecast horizon, the LSTM model turned out to be the best for hyper- and hypoglycemia classes, achieving recall values of 85% and 87% respectively. CONCLUSIONS: Our findings suggest that different models may have varying strengths and weaknesses in predicting glucose level classes, and the choice of model should be carefully considered based on the specific requirements and context of the clinical application. The logistic regression model proved to be more accurate for the next 15 min, particularly in predicting hypoglycemia. However, the LSTM model outperformed logistic regression in predicting glucose level class for the next hour. Future research could explore hybrid models or ensemble approaches that combine the strengths of multiple models to further enhance the accuracy and reliability of glucose predictions.

Performance of intermittently scanned continuous glucose monitoring systems in people with type 1 diabetes: A pooled analysis.

AIMS: To conduct a pooled analysis to assess the performance of intermittently scanned continuous glucose monitoring (isCGM) in association with the rate of change in sensor glucose in a cohort of children, adolescents, and adults with type 1 diabetes. MATERIAL AND METHODS: In this pooled analysis, isCGM system accuracy was assessed depending on the rate of change in sensor glucose. Clinical studies that have been investigating isCGM accuracy against blood glucose, accompanied with collection time points were included in this analysis. isCGM performance was assessed by means of median absolute relative difference (MedARD), Parkes error grid (PEG) and Bland-Altman plot analyses. RESULTS: Twelve studies comprising 311 participants were included, with a total of 15 837 paired measurements. The overall MedARD (interquartile range) was 12.7% (5.9-23.5) and MedARD differed significantly based on the rate of change in glucose (P < 0.001). An absolute difference of -22 mg/dL (-1.2 mmol/L) (95% limits of agreement [LoA] 60 mg/dL (3.3 mmol/L), -103 mg/dL (-5.7 mmol/L)) was found when glucose was rapidly increasing (isCGM glucose minus reference blood glucose), while a -32 mg/dL (1.8 mmol/L) (95% LoA 116 mg/dL (6.4 mmol/L), -51 mg/dL (-2.8 mmol/L)) absolute difference was observed in periods of rapidly decreasing glucose. CONCLUSIONS: The performance of isCGM was good when compared to reference blood glucose measurements. The rate of change in glucose for both increasing and decreasing glucose levels diminished isCGM performance, showing lower accuracy during high rates of glucose change.

Humoral immune response to COVID-19 vaccination in diabetes is age-dependent but independent of type of diabetes and glycaemic control: The prospective COVAC-DM cohort study.

AIMS: To investigate the seroconversion following first and second COVID-19 vaccination in people with type 1 and type 2 diabetes in relation to glycaemic control prior to vaccination and to analyse the response in comparison to individuals without diabetes. MATERIALS AND METHODS: This prospective, multicentre cohort study analysed people with type 1 and type 2 diabetes and a glycated haemoglobin level ≤58 mmol/mol (7.5%) or >58 mmol/mol (7.5%), respectively, and healthy controls. Roche's Elecsys anti-SARS-CoV-2 S immunoassay targeting the receptor-binding domain was used to quantify anti-spike protein antibodies 7 to 14 days after the first and 14 to 21 days after the second vaccination. RESULTS: A total of 86 healthy controls were enrolled in the study, as well as 161 participants with diabetes, of whom 150 (75 with type 1 diabetes and 75 with type 2 diabetes) were eligible for the analysis. After the first vaccination, only 52.7% of participants in the type 1 diabetes group and 48.0% of those in the type 2 diabetes group showed antibody levels above the cut-off for positivity. Antibody levels after the second vaccination were similar in participants with type 1 diabetes, participants with type 2 diabetes and healthy controls after adjusting for age, sex and multiple testing (P > 0.05). Age (r = -0.45, P < 0.001) and glomerular filtration rate (r = 0.28, P = 0.001) were significantly associated with antibody response. CONCLUSIONS: Anti-SARS-CoV-2 S receptor-binding domain antibody levels after the second vaccination were comparable in healthy controls and in participants with type 1 and type 2 diabetes, irrespective of glycaemic control. Age and renal function correlated significantly with the extent of antibody levels.

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.

Myokines and Resistance Training: A Narrative Review.

In the last few years, the muscular system has gained attention due to the discovery of the muscle-secretome and its high potency for retaining or regaining health. These cytokines, described as myokines, released by the working muscle, are involved in anti-inflammatory, metabolic and immunological processes. These are able to influence human health in a positive way and are a target of research in metabolic diseases, cancer, neurological diseases, and other non-communicable diseases. Therefore, different types of exercise training were investigated in the last few years to find associations between exercise, myokines and their effects on human health. Particularly, resistance training turned out to be a powerful stimulus to enhance myokine release. As there are different types of resistance training, different myokines are stimulated, depending on the mode of training. This narrative review gives an overview about resistance training and how it can be utilized to stimulate myokine production in order to gain a certain health effect. Finally, the question of why resistance training is an important key regulator in human health will be discussed.

Rapid glucose rise reduces heart rate variability in adults with type 1 diabetes: A prospective secondary outcome analysis.

To investigate differences in heart rate variability (HRV) during oral glucose tolerance tests (OGTTs) in response to the rate of change in glucose and to different glycaemic ranges in individuals with type 1 diabetes. This was a single-centre, prospective, secondary outcome analysis in 17 individuals with type 1 diabetes (glycated haemoglobin 53 ± 6.3 mmol/L), who underwent two OGTTs (after 12 and 36 hours of fasting) investigating differences in HRV in response to rapid glucose increases/decreases and different glycaemic ranges during OGTT. Based on the rate of change in glucose level, the variables heart rate (P < 0.001), square root of the mean standard difference of successive R-R intervals (P = 0.002), percentage of pairs of R-R intervals with >50 ms difference (P < 0.001) and corrected QT interval (P = 0.04) were significantly altered, with HRV particularly reduced during episodes of rapid glucose rises. Glycaemic ranges during OGTT had no impact on HRV (P < 0.05). Individuals with type 1 diabetes showed no changes in HRV in response to different glycaemic ranges. HRV was dependent on the rate of change in glucose, especially rapid increases in glucose level.

Extent and prevalence of post-exercise and nocturnal hypoglycemia following peri-exercise bolus insulin adjustments in individuals with type 1 diabetes.

AIM: To detail the extent and prevalence of post-exercise and nocturnal hypoglycemia following peri-exercise bolus insulin dose adjustments in individuals with type 1 diabetes (T1D) using multiple daily injections of insulins aspart (IAsp) and degludec (IDeg). METHODS AND RESULTS: Sixteen individuals with T1D, completed a single-centred, randomised, four-period crossover trial consisting of 23-h inpatient phases. Participants administered either a regular (100%) or reduced (50%) dose (100%; 5.1 ± 2.4, 50%; 2.6 ± 1.2 IU, p < 0.001) of individualised IAsp 1 h before and after 45-min of evening exercise at 60 ± 6% V̇O2max. An unaltered dose of IDeg was administered in the morning. Metabolic, physiological and hormonal responses during exercise, recovery and nocturnal periods were characterised. The primary outcome was the number of trial day occurrences of hypoglycemia (venous blood glucose ≤ 3.9 mmol L -1). Inclusion of a 50% IAsp dose reduction strategy prior to evening exercise reduced the occurrence of in-exercise hypoglycemia (p = 0.023). Mimicking this reductive strategy in the post-exercise period decreased risk of nocturnal hypoglycemia (p = 0.045). Combining this strategy to reflect reductions either side of exercise resulted in higher glucose concentrations in the acute post-exercise (p = 0.034), nocturnal (p = 0.001), and overall (p < 0.001) periods. Depth of hypoglycemia (p = 0.302), as well as ketonic and counter-regulatory hormonal profiles were similar. CONCLUSIONS: These findings demonstrate the glycemic safety of peri-exercise bolus dose reduction strategies in minimising the prevalence of acute and nocturnal hypoglycemia following evening exercise in people with T1D on MDI. Use of newer background insulins with current bolus insulins demonstrates efficacy and advances current recommendations for safe performance of exercise. CLINICAL TRIALS REGISTER: DRKS00013509.

The competitive athlete with type 1 diabetes.

Regular exercise is important for health, fitness and longevity in people living with type 1 diabetes, and many individuals seek to train and compete while living with the condition. Muscle, liver and glycogen metabolism can be normal in athletes with diabetes with good overall glucose management, and exercise performance can be facilitated by modifications to insulin dose and nutrition. However, maintaining normal glucose levels during training, travel and competition can be a major challenge for athletes living with type 1 diabetes. Some athletes have low-to-moderate levels of carbohydrate intake during training and rest days but tend to benefit, from both a glucose and performance perspective, from high rates of carbohydrate feeding during long-distance events. This review highlights the unique metabolic responses to various types of exercise in athletes living with type 1 diabetes. Graphical abstract.

Glucose management for exercise using continuous glucose monitoring (CGM) and intermittently scanned CGM (isCGM) systems in type 1 diabetes: position statement of the European Association for the Study of Diabetes (EASD) and of the International Society for Pediatric and Adolescent Diabetes (ISPAD) endorsed by JDRF and supported by the American Diabetes Association (ADA).

Physical exercise is an important component in the management of type 1 diabetes across the lifespan. Yet, acute exercise increases the risk of dysglycaemia, and the direction of glycaemic excursions depends, to some extent, on the intensity and duration of the type of exercise. Understandably, fear of hypoglycaemia is one of the strongest barriers to incorporating exercise into daily life. Risk of hypoglycaemia during and after exercise can be lowered when insulin-dose adjustments are made and/or additional carbohydrates are consumed. Glycaemic management during exercise has been made easier with continuous glucose monitoring (CGM) and intermittently scanned continuous glucose monitoring (isCGM) systems; however, because of the complexity of CGM and isCGM systems, both individuals with type 1 diabetes and their healthcare professionals may struggle with the interpretation of given information to maximise the technological potential for effective use around exercise (i.e. before, during and after). This position statement highlights the recent advancements in CGM and isCGM technology, with a focus on the evidence base for their efficacy to sense glucose around exercise and adaptations in the use of these emerging tools, and updates the guidance for exercise in adults, children and adolescents with type 1 diabetes. Graphical abstract.

Bolus insulin dose depends on previous-day race intensity during 5 days of professional road-cycle racing in athletes with type 1 diabetes: A prospective observational study.

AIMS: To assess insulin therapy, macronutrient intake and glycaemia in professional cyclists with type 1 diabetes (T1D) over a 5-day Union Cycliste Internationale road-cycle race. MATERIAL AND METHODS: In this prospective observational study, seven professional cyclists with T1D (age 28 ± 4 years, body mass index 20.9 ± 0.9 kg/m2 , glycated haemoglobin concentration 56 ± 7 mmol/mol [7.3% ± 0.6%]) were monitored during a five-stage professional road cycling race. Real-time continuous glucose monitoring (rtCGM) data, smart insulin pen dose data and macronutrient intake were assessed by means of repeated-measure one-way ANOVA and post hoc testing. Associations between exercise physiological markers and rtCGM data, insulin doses and macronutrient intake were assessed via linear regression modelling (P ≤ 0.05). RESULTS: Bolus insulin dose was significantly reduced over the 5-day period (P = 0.03), while carbohydrate intake (P = 0.24) and basal insulin doses remained unchanged (P = 0.64). A higher mean previous-day race intensity was associated with a lower mean sensor glucose level (P = 0.03), less time above range level 2 (>13.9 mmol/L [250 mg/dL]; P = 0.05) and lower doses of bolus insulin (P = 0.04) on the subsequent day. No significant associations were found for any other glycaemic range and glycaemic variability (P > 0.05). CONCLUSIONS: This is the first study to demonstrate the influence of previous-day race intensity on subsequent bolus insulin dose requirements in professional cyclists with T1D. These data may help inform therapeutic strategies to ensure safe exercise performance.

Glucose management for exercise using continuous glucose monitoring (CGM) and intermittently scanned CGM (isCGM) systems in type 1 diabetes: position statement of the European Association for the Study of Diabetes (EASD) and of the International Society for Pediatric and Adolescent Diabetes (ISPAD) endorsed by JDRF and supported by the American Diabetes Association (ADA).

Physical exercise is an important component in the management of type 1 diabetes across the lifespan. Yet, acute exercise increases the risk of dysglycaemia, and the direction of glycaemic excursions depends, to some extent, on the intensity and duration of the type of exercise. Understandably, fear of hypoglycaemia is one of the strongest barriers to incorporating exercise into daily life. Risk of hypoglycaemia during and after exercise can be lowered when insulin-dose adjustments are made and/or additional carbohydrates are consumed. Glycaemic management during exercise has been made easier with continuous glucose monitoring (CGM) and intermittently scanned continuous glucose monitoring (isCGM) systems; however, because of the complexity of CGM and isCGM systems, both individuals with type 1 diabetes and their healthcare professionals may struggle with the interpretation of given information to maximise the technological potential for effective use around exercise (ie, before, during and after). This position statement highlights the recent advancements in CGM and isCGM technology, with a focus on the evidence base for their efficacy to sense glucose around exercise and adaptations in the use of these emerging tools, and updates the guidance for exercise in adults, children and adolescents with type 1 diabetes.

Performance of the Freestyle Libre flash glucose monitoring (flash GM) system in individuals with type 1 diabetes: A secondary outcome analysis of a randomized crossover trial.

AIMS: The efficacy of flash glucose monitoring (flash GM) systems has been demonstrated by improvements in glycaemia; however, during high rates of glucose flux, the performance of continuous glucose monitoring systems was impaired, as detailed in previous studies. This study aimed to determine the performance of the flash GM system during daily-life glycaemic challenges such as carbohydrate-rich meals, bolus insulin-induced glycaemic disturbances and acute physical exercise in individuals with type 1 diabetes. MATERIALS AND METHODS: This study comprised four randomized trial visits with alternating pre- and post-exercise bolus insulin doses. Throughout the four 14-hour inpatient phases, 19 participants received three carbohydrate-rich meals and performed moderate-intensity exercise. Venous blood glucose and capillary blood glucose during exercise was compared to interstitial glucose concentrations. Flash GM accuracy was assessed by median absolute relative difference (MARD) (interquartile range [IQR]) using the Bland-Altman method and Clark error grid, as well as according to guidelines for integrated CGM approvals (Class II-510(K)). RESULTS: The overall MARD (IQR) during inpatient phases was 14.3% (6.9%-22.8%), during hypoglycaemia (≤3.9 mmol/L) was 31.6% (16.2%-46.8%), during euglycaemia (4.0 mmol/L - 9.9 mmol/L) was 16.0% (8.5%-24.0%) and during hyperglycaemia (≥10 mmol/L) was 9.4% (5.1%-15.7%). Overall Bland-Altman analysis showed a bias (95% LoA) of 1.26 mmol/L (-1.67 to 4.19 mmol/L). The overall MARD during acute exercise was 29.8% (17.5%-39.8%), during hypoglycaemia was 45.1% (35.2%-51.1%), during euglycaemia was 30.7% (18.7%-39.2%) and during hyperglycaemia was 16.3% (10.0%-22.8%). CONCLUSION: Flash GM interstitial glucose readings were not sufficiently accurate within the hypoglycaemic range and during acute exercise and require confirmatory blood glucose measurements.