Impact of bedtime snack composition on prevention of nocturnal hypoglycemia in adults with type 1 diabetes undergoing intensive insulin management using lispro insulin before meals: a randomized, placebo-controlled, crossover trial

Combining uncertainty-aware predictive modeling and a bedtime Smart Snack intervention to prevent nocturnal hypoglycemia in people with type 1 diabetes on multiple daily injections

OBJECTIVE

Nocturnal hypoglycemia is a known challenge for people with type 1 diabetes, especially for physically active individuals or those on multiple daily injections. We developed an evidential neural network (ENN) to predict at bedtime the probability and timing of nocturnal hypoglycemia (0-4 vs 4-8 h after bedtime) based on several glucose metrics and physical activity patterns. We utilized these predictions in silico to prescribe bedtime carbohydrates with a Smart Snack intervention specific to the predicted minimum nocturnal glucose and timing of nocturnal hypoglycemia.

MATERIALS AND METHODS

We leveraged free-living datasets collected from 366 individuals from the T1DEXI Study and Glooko. Inputs to the ENN used to model nocturnal hypoglycemia were derived from demographic information, continuous glucose monitoring, and physical activity data. We assessed the accuracy of the ENN using area under the receiver operating curve, and the clinical impact of the Smart Snack intervention through simulations.

RESULTS

The ENN achieved an area under the receiver operating curve of 0.80 and 0.71 to predict nocturnal hypoglycemic events during 0-4 and 4-8 h after bedtime, respectively, outperforming all evaluated baseline methods. Use of the Smart Snack intervention reduced probability of nocturnal hypoglycemia from 23.9 ± 14.1% to 14.0 ± 13.3% and duration from 7.4 ± 7.0% to 2.4 ± 3.3% in silico.

DISCUSSION

Our findings indicate that the ENN-based Smart Snack intervention has the potential to significantly reduce the frequency and duration of nocturnal hypoglycemic events.

CONCLUSION

A decision support system that combines prediction of minimum nocturnal glucose and proactive recommendations for bedtime carbohydrate intake might effectively prevent nocturnal hypoglycemia and reduce the burden of glycemic self-management.

Uncooked cornstarch for the prevention of hypoglycemic events

Hypoglycemia is a pathological condition characterized by a low plasma glucose concentration associated with typical autonomic and/or neuroglycopenic symptoms, and resolution of these symptoms with carbohydrate consumption. Hypoglycemia is quite common in clinical practice, particularly in insulin-treated patients with diabetes and in other inherited or acquired conditions involving the regulation of glucose metabolism. Beyond symptoms that might strongly affect the quality of life, hypoglycemia can lead to short- and long-term detrimental consequences for health. Hypoglycemia can be prevented by appropriate changes in dietary habits or by relevant modifications of the drug treatment. Several dietary approaches based on the intake of various carbohydrate foods have been tested for hypoglycemia prevention; among them uncooked cornstarch (UCS) has demonstrated a great efficacy. In this narrative review, we have summarized the current evidence on the UCS usefulness in some conditions characterized by high hypoglycemic risk, focusing on some inherited diseases -i.e. glycogen storage diseases and other rare disorders - and acquired conditions such as type 1 diabetes, postprandial hypoglycemia consequent to esophageal-gastric or bariatric surgery, and insulin autoimmune syndrome. We also considered the possible role of UCS during endurance exercise performance. Lastly, we have discussed the dose requirement, the side effects, the limitations of UCS use, and the plausible mechanisms by which UCS could prevent hypoglycemia.

Nutrition and Exercise Performance in Adults With Type 1 Diabetes

The best nutritional practices for exercise and sports performance are largely activity specific. The presence of type 1 diabetes undeniably bestows additional factors to consider to manage exercise and ensure adequate nutrients and fuels are available for optimal performance. Whether participating in sports or physical activity on a recreational basis or striving to achieve a high level of athletic performance, individuals with type 1 diabetes must pay attention to their nutritional and dietary patterns, including intake of macronutrients, micronutrients, fluids and supplements, such as caffeine to maintain metabolic and glycemic balance. Performance aside, nutritional recommendations may also differ on an individual basis relative to exercise, glycemic management and body weight goals. Balancing all these dietary factors can be challenging for individuals with type 1 diabetes, and many related aspects have yet to be fully researched in this population.

Repeated measures random forests (RMRF): Identifying factors associated with nocturnal hypoglycemia

Nocturnal hypoglycemia is a common phenomenon among patients with diabetes and can lead to a broad range of adverse events and complications. Identifying factors associated with hypoglycemia can improve glucose control and patient care. We propose a repeated measures random forest (RMRF) algorithm that can handle nonlinear relationships and interactions and the correlated responses from patients evaluated over several nights. Simulation results show that our proposed algorithm captures the informative variable more often than naïvely assuming independence. RMRF also outperforms standard random forest and extremely randomized trees algorithms. We demonstrate scenarios where RMRF attains greater prediction accuracy than generalized linear models. We apply the RMRF algorithm to analyze a diabetes study with 2524 nights from 127 patients with type 1 diabetes. We find that nocturnal hypoglycemia is associated with HbA1c, bedtime blood glucose (BG), insulin on board, time system activated, exercise intensity, and daytime hypoglycemia. The RMRF can accurately classify nights at high risk of nocturnal hypoglycemia.

Prediction of Nocturnal Hypoglycemia in Adults with Type 1 Diabetes under Multiple Daily Injections Using Continuous Glucose Monitoring and Physical Activity Monitor

(1) Background: nocturnal hypoglycemia (NH) is one of the most challenging side effects of multiple doses of insulin (MDI) therapy in type 1 diabetes (T1D). This work aimed to investigate the feasibility of a machine-learning-based prediction model to anticipate NH in T1D patients on MDI. (2) Methods: ten T1D adults were studied during 12 weeks. Information regarding T1D management, continuous glucose monitoring (CGM), and from a physical activity tracker were obtained under free-living conditions at home. Supervised machine-learning algorithms were applied to the data, and prediction models were created to forecast the occurrence of NH. Individualized prediction models were generated using multilayer perceptron (MLP) and a support vector machine (SVM). (3) Results: population outcomes indicated that more than 70% of the NH may be avoided with the proposed methodology. The predictions performed by the SVM achieved the best population outcomes, with a sensitivity and specificity of 78.75% and 82.15%, respectively. (4) Conclusions: our study supports the feasibility of using ML techniques to address the prediction of nocturnal hypoglycemia in the daily life of patients with T1D on MDI, using CGM and a physical activity tracker.

Impact of dietary protein on postprandial glycaemic control and insulin requirements in Type 1 diabetes: a systematic review

AIM

Postprandial hyperglycaemia is a challenge for people living with Type 1 diabetes. In addition to carbohydrate, dietary protein has been shown to contribute to postprandial glycaemic excursions with recommendations to consider protein when calculating mealtime insulin doses. The aim of this review is to identify and synthesize evidence about the glycaemic impact of dietary protein and insulin requirements for individuals with Type 1 diabetes.

METHODS

A systematic literature search of relevant biomedical databases was performed to identify research on the glycaemic impact of dietary protein when consumed alone, and in combination with other macronutrients in individuals with Type 1 diabetes.

RESULTS

The review included 14 published studies dated from 1992 to 2018, and included studies that researched the impact of protein alone (n = 2) and protein in a mixed meal (n = 12). When protein was consumed alone a glycaemic effect was not seen until ≥ 75 g. In a carbohydrate-containing meal ≥ 12.5 g of protein impacted the postprandial glucose. Inclusion of fat in a high-protein meal enhanced the glycaemic response and further increased insulin requirements. The timing of the glycaemic effect from dietary protein ranged from 90 to 240 min. Studies indicate that the postprandial glycaemic response and insulin requirements for protein are different when protein is consumed alone or with carbohydrate and/or fat.

CONCLUSIONS

This systematic review provides evidence that dietary protein contributes to postprandial glycaemic excursions and insulin requirements. These insights have important implications for the education of people with Type 1 diabetes and highlights the need for more effective insulin dosing strategies for mixed macronutrient meals.

An on-line support tool to reduce exercise-related hypoglycaemia and improve confidence to exercise in type 1 diabetes

OBJECTIVE

Hypoglycaemia related to exercise and lack of confidence to exercise, are common in T1DM. An online educational exercise tool (ExT1D) was tested to determine whether these parameters can be improved.

RESEARCH DESIGN AND METHODS

Thirty two adults with T1DM (50%M, age 35.8 ± 9.5 yr diabetes duration 12.3 ± 9.9 yr, median HbA1c 7.1%[ICR 6.4-7.7] NGSPU) exercising ≥ 60 min/week enrolled in a RCT utilising ExT1D, with partial cross-over design. The primary end-point was Exercise-related hypoglycaemia (ErH) number corrected for exercise session number, with ErH defined as CGM episodes < 4.0 mM occurring within 24 h of exercise. Secondary RCT endpoints were total ErH duration, and ErH duration/episode. A pre-defined longitudinal analysis with each subject compared with their baseline was also undertaken, for the three ErH parameters, and using fear of hypoglycaemia questionnaires.

RESEARCH

In the RCT a 50% lower median ErH number (P = 0.6) (37% lower ErH number per exercise session (P = 0.06, NS primary endpoint) occurred in the Intervention vs Control group. A 49% lower ErH duration per episode (P = 0.2), and 80% less ErH duration (P = 0.3), were also observed in the Intervention vs Control group. In the longitudinal study, ErH number reduced by 43% (P = 0.088), ErH duration per episode by 52% (P = 0.157) and total duration of ErH fell by 71% (P = 0.015). Confidence to prevent glucose lowering by exercise also improved (P = 0.039). Post-hoc analysis showed those with the greatest ErH events at baseline benefited most. Fructosamine and HbA1c levels were unchanged from baseline.

CONCLUSIONS

ExT1D can reduce exercise-related hypoglycaemia and provide greater confidence to exercise.

Night-time eating and body weight status among US adults, 2007-2016

BACKGROUND

The present study assessed the relationship between night-time eating and body weight status among US adults, using in-person 24-h dietary recall data from a nationally representative survey.

METHODS

Individual-level data (n = 23 003) came from the 2007-2016 National Health and Nutrition Examination Survey (NHANES) (five waves). Multivariate linear and logistic regressions were performed to estimate the effect of energy, sugar, fat and saturated fat intake during night-time on body mass index (BMI), obesity (BMI ≥30 kg m^-2 ), waist circumference (WC) and abdominal obesity (WC ≥88 cm in women; WC ≥102 cm in men), adjusting for daily total energy intake, physical activity, sleeping and other individual characteristics.

RESULTS

Approximately 36.5% and 56.7% of the NHANES adult participants had obesity and abdominal obesity, respectively. The proportion of energy, total fat, saturated fat and total sugar intake within the time window of 00.00 h to 05.59 h and 22.00 h to 23.59 h averaged 5.7%, 5.3%, 5.7% and 6.8%, respectively. Energy intake within the time window was not found to be associated with BMI, WC, obesity or abdominal obesity in the regression analyses. Sensitivity analyses applying alternative time windows to capture night-time eating found night-time intakes of energy, total fat, saturated fat and total sugar not to be associated BMI, WC, obesity or abdominal obesity.

CONCLUSIONS

Night-time eating was not found to be associated with body weight status in a US nationally representative adult sample. Restricting night-time food consumption alone without an overall reduction in daily caloric intake may not prevent obesity. The findings of the present study warrant replication in a future experimental study with habitual dietary behaviour measures.

Exercise Management for Young People With Type 1 Diabetes: A Structured Approach to the Exercise Consultation

Regular physical activity during childhood is important for optimal physical and psychological development. For individuals with Type 1 Diabetes (T1D), physical activity offers many health benefits including improved glycemic control, cardiovascular function, blood lipid profiles, and psychological well-being. Despite these benefits, many young people with T1D do not meet physical activity recommendations. Barriers to engaging in a physically active lifestyle include fear of hypoglycemia, as well as insufficient knowledge in managing diabetes around exercise in both individuals and health care professionals. Diabetes and exercise management is complex, and many factors can influence an individual's glycemic response to exercise including exercise related factors (such as type, intensity and duration of the activity) and person specific factors (amount of insulin on board, person's stress/anxiety and fitness levels). International guidelines provide recommendations for clinical practice, however a gap remains in how to apply these guidelines to a pediatric exercise consultation. Consequently, it can be challenging for health care practitioners to advise young people with T1D how to approach exercise management in a busy clinic setting. This review provides a structured approach to the child/adolescent exercise consultation, based on a framework of questions, to assist the health care professional in formulating person-specific exercise management plans for young people with T1D.

The risks of nocturnal hypoglycaemia in insulin-treated diabetes

Over half of all episodes of severe hypoglycaemia (requiring external help) occur during sleep, but nocturnal hypoglycaemia is often asymptomatic and unrecognised. The precise incidence of nocturnal hypoglycaemia is difficult to determine with no agreed definition, but continuous glucose monitoring has shown that it occurs frequently in people taking insulin. Attenuation of the counter-regulatory responses to hypoglycaemia during sleep may explain why some episodes are undetected and more prolonged, and modifies cardiovascular responses. The morbidity and mortality associated with nocturnal hypoglycaemia is probably much greater than realised, causing seizures, coma and cardiovascular events and affecting quality of life, mood and work performance the following day. It may induce impaired awareness of hypoglycaemia. Cardiac arrhythmias that occur during nocturnal hypoglycaemia include bradycardia and ectopics that may provoke dangerous arrhythmias. Treatment strategies are discussed that may help to minimise the frequency of nocturnal hypoglycaemia.

Efficacy of an Overnight Predictive Low-Glucose Suspend System in Relation to Hypoglycemia Risk Factors in Youth and Adults With Type 1 Diabetes

BACKGROUND

We developed a system to suspend insulin pump delivery overnight when the glucose trend predicts hypoglycemia. This predictive low-glucose suspend (PLGS) system substantially reduces nocturnal hypoglycemia without an increase in morning ketosis. Evaluation of hypoglycemia risk factors that could potentially influence the efficacy of the system remains critical for understanding possible problems with the system and identifying patients that may have the greatest benefit when using the system.

METHODS

The at-home randomized trial consisted of 127 study participants with hemoglobin A1c (A1C) of ≤8.5% (mmol/mol) for patients aged 4-14 years and ≤8.0% for patient aged 15-45 years. Factors assessed included age, gender, A1C, diabetes duration, daily percentage basal insulin, total daily dose of insulin (units/kg-day), bedtime BG, bedtime snack, insulin on board, continuous glucose monitor (CGM) rate of change (ROC), day of the week, time system activated, daytime exercise intensity, and daytime CGM-measured hypoglycemia.

RESULTS

The PLGS system was effective in preventing hypoglycemia for each factor subgroup. There was no evidence that the PLGS system was more or less effective in preventing hypoglycemia in any one subgroup compared with the other subgroups based on that factor. In addition, the effect of the system on overnight hyperglycemia did not differ in subgroups.

CONCLUSIONS

The PLGS system tested in this study effectively reduced hypoglycemia without a meaningful increase in hyperglycemia across a variety of factors.

Influence of dietary protein on postprandial blood glucose levels in individuals with Type 1 diabetes mellitus using intensive insulin therapy

AIM

To determine the effects of protein alone (independent of fat and carbohydrate) on postprandial glycaemia in individuals with Type 1 diabetes mellitus using intensive insulin therapy.

METHODS

Participants with Type 1 diabetes mellitus aged 7-40 years consumed six 150 ml whey isolate protein drinks [0 g (control), 12.5, 25, 50, 75 and 100] and two 150 ml glucose drinks (10 and 20 g) without insulin, in randomized order over 8 days, 4 h after the evening meal. Continuous glucose monitoring was used to assess postprandial glycaemia.

RESULTS

Data were collected from 27 participants. Protein loads of 12.5 and 50 g did not result in significant postprandial glycaemic excursions compared with control (water) throughout the 300 min study period (P > 0.05). Protein loads of 75 and 100 g resulted in lower glycaemic excursions than control in the 60-120 min postprandial interval, but higher excursions in the 180-300 min interval. In comparison with 20 g glucose, the large protein loads resulted in significantly delayed and sustained glucose excursions, commencing at 180 min and continuing to 5 h.

CONCLUSIONS

Seventy-five grams or more of protein alone significantly increases postprandial glycaemia from 3 to 5 h in people with Type 1 diabetes mellitus using intensive insulin therapy. The glycaemic profiles resulting from high protein loads differ significantly from the excursion from glucose in terms of time to peak glucose and duration of the glycaemic excursion. This research supports recommendations for insulin dosing for large amounts of protein.

The health impact of nighttime eating: old and new perspectives

Nighttime eating, particularly before bed, has received considerable attention. Limiting and/or avoiding food before nighttime sleep has been proposed as both a weight loss strategy and approach to improve health and body composition. Indeed, negative outcomes have been demonstrated in response to large mixed meals in populations that consume a majority of their daily food intake during the night. However, data is beginning to mount to suggest that negative outcomes may not be consistent when the food choice is small, nutrient-dense, low energy foods and/or single macronutrients rather than large mixed-meals. From this perspective, it appears that a bedtime supply of nutrients can promote positive physiological changes in healthy populations. In addition, when nighttime feeding is combined with exercise training, any adverse effects appear to be eliminated in obese populations. Lastly, in Type I diabetics and those with glycogen storage disease, eating before bed is essential for survival. Nevertheless, nighttime consumption of small (~150 kcals) single nutrients or mixed-meals does not appear to be harmful and may be beneficial for muscle protein synthesis and cardiometabolic health. Future research is warranted to elucidate potential applications of nighttime feeding alone and in combination with exercise in various populations of health and disease.

Association between post-dinner dietary intakes and nocturnal hypoglycemic risk in adult patients with type 1 diabetes

AIMS

To describe (i) current bedtime nutritional practices and (ii) the association between post-dinner dietary intake and the occurrence of non-severe nocturnal hypoglycemia (NH) in real-life conditions among adult patients with type 1 diabetes using insulin analogs.

METHODS

One hundred adults (median [interquartile range]: age 46.4 [36.0-55.8] years, HbA1c 7.9 [7.3-8.6] % (63 [56-70] mmol/mol)) using multiple daily injections (n=67) or insulin pump (n=33) wore a blinded continuous glucose monitoring system and completed a food diary for 72-h.

RESULTS

NH occurred on 28% of 282 nights analyzed. (i) Patients reported post-dinner dietary intakes on 63% of the evenings. They injected rapid-acting insulin boluses on 64 occasions (23% of 282 evenings). These insulin boluses were mostly injected with (n=37) dietary intakes. (ii) Post-dinner dietary intake was not associated with NH occurrence in univariate analyses. In multivariate analyses, the injection of rapid-acting insulin modulated the association between post-dinner dietary intake and NH: with insulin, post-dinner carbohydrate intake was positively associated with NH (odds ratio (OR): 1.16 [95% confidence interval, CI: 1.04-1.29] per 5g increase, p=0.008); without insulin, post-dinner protein intake was inversely associated with NH occurrence (OR [95% CI]: 0.88 [0.78-1.00] per 2g increase, p=0.048).

CONCLUSIONS

NH remains frequent in adults with type 1 diabetes. There is a complex relationship between post-dinner dietary intake and NH occurrence, including the significant role of nutrient content and rapid-acting insulin injection that requires further investigation.

Are bedtime nutritional strategies effective in preventing nocturnal hypoglycaemia in patients with type 1 diabetes?

Hypoglycaemia remains the major limiting factor for adequate diabetes control for patients with type 1 diabetes (T1D), especially during the night-time. Although nutritional strategies for nocturnal hypoglycaemia (NH) prevention are regularly suggested in clinical practice, there is no evidence-based recommendation for the usefulness and optimal composition of a bedtime snack. The aim of this narrative review was to analyse the current state of knowledge on nutritional strategies to prevent NH in individuals with T1D. A literature search was conducted, using PubMed and Medline (1946 to 2013); 16 studies were retrieved. Overall, the level of evidence was low. Results indicated that a calibrated bedtime snack based on bedtime blood glucose (BG) level could be effective to reduce NH occurrence for patients treated with human or animal insulin (short-acting combined with lente, ultralente and/or intermediate-acting insulin), but there is no evidence for patients treated with insulin analogues as part of multiple daily injections or insulin pump regimen. Some evidence suggests that including uncooked cornstarch or alanine in the bedtime snack composition could provide some benefits for the prevention of NH. Individualized recommendations of a bedtime snack intake for patients or situations at high risk for NH (long standing diabetes, hypoglycaemia unawareness, prior physical activity, alcohol consumption, bedtime BG close to hypoglycaemia threshold) appear as a prudent recommendation. On the basis of the available evidence, a bedtime snack cannot be recommended systematically but it might be useful if prescribed in an individualized fashion; further research is needed to evaluate these strategies.

Nutritional strategies to prevent hypoglycemia at exercise in diabetic adolescents

Studies on nutritional strategies to prevent exercise-induced hypoglycemia in adolescents with type 1 diabetes are scarce.

OBJECTIVE

This study aimed to compare the effect of two food strategies on blood glucose (BG) during and after 60 min of moderate-intensity exercise.

METHODS

Subjects performed exercise 120 min after breakfast in three conditions: 1) standardized breakfast + preexercise placebo beverage (PL), 2) standardized breakfast + preexercise CHO beverage (8 mg of CHO·kg of body weight·min of exercise; CHO), or 3) protein-supplemented breakfast (8 mg of protein·kg of body weight·min of exercise added to the standardized breakfast) + preexercise placebo beverage (PROT). As soon as BG falls <4 mmol·L or symptomatic hypoglycemia occurred during exercise, the session was stopped and CHO tablets were provided to correct hypoglycemia.

RESULTS

Ten subjects (age = 14.0 ± 1.5 yr) participated in all conditions. BG decreased by 6.0 ± 1.9, 1.0 ± 3.1, and 4.6 ± 1.9 mmol·L in PL, CHO, and PROT conditions, respectively (P < 0.05). The proportion of subjects reaching hypoglycemic values or sensations of hypoglycemia was significantly different between conditions with 4/10, 1/10, and 0/10 in the PL, CHO, and PROT conditions (P < 0.05).

CONCLUSIONS

The preexercise CHO beverage induced the least dramatic BG decrease during exercise. The PROT breakfast induced an overall similar BG drop compared to PL, a larger BG drop compared to CHO, but a similar rate of hypoglycemia compared to CHO. Our results suggest that taking CHO supplement before unplanned exercise is still the best strategy to prevent exercise-induced hypoglycemia in an adolescent population. However, a protein supplement strategy may also have some benefits in limiting the rate of hypoglycemia during and immediately after exercise.

Hypoglycemia and diabetes: a report of a workgroup of the American Diabetes Association and the Endocrine Society

OBJECTIVE

To review the evidence about the impact of hypoglycemia on patients with diabetes that has become available since the past reviews of this subject by the American Diabetes Association and The Endocrine Society and to provide guidance about how this new information should be incorporated into clinical practice.

PARTICIPANTS

Five members of the American Diabetes Association and five members of The Endocrine Society with expertise in different aspects of hypoglycemia were invited by the Chair, who is a member of both, to participate in a planning conference call and a 2-day meeting that was also attended by staff from both organizations. Subsequent communications took place via e-mail and phone calls. The writing group consisted of those invitees who participated in the writing of the manuscript. The workgroup meeting was supported by educational grants to the American Diabetes Association from Lilly USA, LLC and Novo Nordisk and sponsorship to the American Diabetes Association from Sanofi. The sponsors had no input into the development of or content of the report.

EVIDENCE

The writing group considered data from recent clinical trials and other studies to update the prior workgroup report. Unpublished data were not used. Expert opinion was used to develop some conclusions.

CONSENSUS PROCESS

Consensus was achieved by group discussion during conference calls and face-to-face meetings, as well as by iterative revisions of the written document. The document was reviewed and approved by the American Diabetes Association's Professional Practice Committee in October 2012 and approved by the Executive Committee of the Board of Directors in November 2012 and was reviewed and approved by The Endocrine Society's Clinical Affairs Core Committee in October 2012 and by Council in November 2012.

CONCLUSIONS

The workgroup reconfirmed the previous definitions of hypoglycemia in diabetes, reviewed the implications of hypoglycemia on both short- and long-term outcomes, considered the implications of hypoglycemia on treatment outcomes, presented strategies to prevent hypoglycemia, and identified knowledge gaps that should be addressed by future research. In addition, tools for patients to report hypoglycemia at each visit and for clinicians to document counseling are provided.

Hypoglycemia and diabetes: a report of a workgroup of the American Diabetes Association and the Endocrine Society

OBJECTIVE

To review the evidence about the impact of hypoglycemia on patients with diabetes that has become available since the past reviews of this subject by the American Diabetes Association and The Endocrine Society and to provide guidance about how this new information should be incorporated into clinical practice.

PARTICIPANTS

Five members of the American Diabetes Association and five members of The Endocrine Society with expertise in different aspects of hypoglycemia were invited by the Chair, who is a member of both, to participate in a planning conference call and a 2-day meeting that was also attended by staff from both organizations. Subsequent communications took place via e-mail and phone calls. The writing group consisted of those invitees who participated in the writing of the manuscript. The workgroup meeting was supported by educational grants to the American Diabetes Association from Lilly USA, LLC and Novo Nordisk and sponsorship to the American Diabetes Association from Sanofi. The sponsors had no input into the development of or content of the report.

EVIDENCE

The writing group considered data from recent clinical trials and other studies to update the prior workgroup report. Unpublished data were not used. Expert opinion was used to develop some conclusions.

CONSENSUS PROCESS

Consensus was achieved by group discussion during conference calls and face-to-face meetings, as well as by iterative revisions of the written document. The document was reviewed and approved by the American Diabetes Association's Professional Practice Committee in October 2012 and approved by the Executive Committee of the Board of Directors in November 2012 and was reviewed and approved by The Endocrine Society's Clinical Affairs Core Committee in October 2012 and by Council in November 2012.

CONCLUSIONS

The workgroup reconfirmed the previous definitions of hypoglycemia in diabetes, reviewed the implications of hypoglycemia on both short- and long-term outcomes, considered the implications of hypoglycemia on treatment outcomes, presented strategies to prevent hypoglycemia, and identified knowledge gaps that should be addressed by future research. In addition, tools for patients to report hypoglycemia at each visit and for clinicians to document counseling are provided.

Effect of dietary protein on post-prandial glucose in patients with type 1 diabetes

BACKGROUND

In flexible insulin therapy, determination of the prandial insulin dose only takes into account the carbohydrate content of the evening meal, and not the protein content. Protein can, however, contribute to gluconeogenesis. We compared the glycaemic effect of a standard evening meal with that of a test evening meal enriched in protein.

METHODS

The present study was conducted in 28 C-peptide negative patients with type 1 diabetes. Two evening meals that were similar in content, except that one was enriched by the addition of 300 g of 0%-fat fromage frais, were taken on two consecutive days. Insulin doses were maintained exactly the same before both evening meals. Patients were monitored with a continuous glucose-monitoring device.

RESULTS

Patients ate similar quantities at both evening meals, except for protein (21.5 g more at the test evening meal). The preprandial insulin dose was 0.96 (0.4) U per 10 g carbohydrates. After correction for differences of interstitial glucose at the start of the evening meals, both interstitial and capillary glucose levels were similar after both evening meals, except for the late-post-prandial interstitial glucose level.

CONCLUSIONS

We found no effect of dietary protein on post-prandial-, overnight- or late-night glucose levels in patients with type 1 diabetes. This confirms that dietary proteins need not be included in the calculation of prandial insulin dose.

Clinical management of the physically active patient with type 1 diabetes

The prevalence and incidence of type 1 diabetes continues to increase worldwide. Most patients with type 1 diabetes are young at the time of diagnosis and wish to continue leading a physically active life. Although regular exercise, insulin therapy, and proper nutrition are the cornerstone of treatment, there are considerable challenges in managing the active individual with type 1 diabetes. The current recommendation for diabetes management is intensive glycemic control for all patients when possible to help prevent secondary complications. Both insulin pump therapy and multiple daily injections are beneficial treatment options to lower average glucose levels; however, without continuous glucose monitoring, these treatment options typically increase the risk of hypoglycemia. In active patients with type 1 diabetes, the challenges of maintaining good glycemia are complicated by the inability to regulate insulin concentrations during and after exercise. Physiological and psychosocial factors during growth and maturation also provide additional challenges. This article highlights challenges and key strategies for diabetes management in the active individual with type 1 diabetes, including the application of the most recent diabetes technologies.

Sleep and the response to hypoglycaemia

Undetected nocturnal hypoglycaemia frequently occurs in patients with diabetes, having a negative influence on well-being, counterregulation against and awareness of subsequent hypoglycaemia, and even causing sudden death in some cases most likely by inducing cardiac arrhythmia. Sleep markedly weakens the neuroendocrine defence mechanism against hypoglycaemia by shifting the glycaemic threshold for counterregulatory activation to lower levels. While hypoglycaemia triggers awakening in healthy subjects, patients with type 1 diabetes frequently fail to awake in the presence of low plasma glucose levels. Little is known about the frequency of and responses to nocturnal hypoglycaemia in patients with type 2 diabetes. Unfortunately, effective strategies to prevent or even safely detect nocturnal hypoglycaemia are still lacking. Taken together, hypoglycaemia occurring during sleep presents a major, often neglected problem in the management of diabetic patients. Different aspects of this phenomenon such as responses to and consequences of nocturnal hypoglycaemia as well as strategies for its prevention are highlighted in this review.

Low-fat vs. high-fat bedtime snacks in children and adolescents with type 1 diabetes

OBJECTIVE

The purpose of this study was to determine whether, in a group of children with type 1 diabetes using insulin pump, a prebedtime snack with a relatively high fat content provides greater protection from nocturnal hypoglycemia than a snack containing the same amount of carbohydrate and protein but a lower fat content.

RESEARCH DESIGN AND METHODS

Ten subjects, aged 6 to <18 yr, in a trial evaluating the Abbott Navigator glucose sensor, agreed to this ancillary study. On 12 or more separate nights, each subject was randomized by a Web site to a carbohydrate-low-fat (30 g CHO, 2.5 g protein, and 1.3 g fat; 138 kcal) snack or a carbohydrate-high-fat (30 g CHO, 2 g protein, and 20 g fat; 320 kcal) snack. Subjects used their usual evening snack algorithm to determine the size (in 15-g carbohydrate increments) and insulin dosage.

RESULTS

Average glucose on 128 valid study nights before snack was similar in both groups. The proportion of nights with hypoglycemia (a sensor or meter glucose value or=200 mg/dL and at least 50 mg/dL above baseline, 35% high fat vs. 30% low fat).

CONCLUSIONS

There were no statistical differences between the high- and low-fat snacks on the frequency of hyperglycemia or hypoglycemia. This study highlights the feasibility of web-based research in patients' home environment.

High volume-low intensity exercise camp and glycemic control in diabetic children

AIM

To evaluate the effects of the designed regime encompassing high volume-low intensity physical activity programme on glycemic control in diabetic children, 20 subjects (age 12.81 +/- 2.14) spent 2 weeks in a controlled environment of a summer camp.

METHODS

An exercise physiologist and a kinesiology specialist programme and conducted the three exercise sessions a day. Total daily caloric intake was controlled and the blood glucose was monitored four times a day with special concern for hypoglycaemia episodes. Short and long-term effects (HbA1c) of the summer camp were evaluated 10 days and 2 months following programme completion. The insulin dosage was not lowered at the beginning of the camp for everyone, but it was individually modified according to the blood glucose monitoring.

RESULTS

Initial HbA1c was 8.28 +/- 1.3% and decreased to 7.92 +/- 1.42% measured 10 days after the camp (P = 0.023) while the number of children with the satisfactory HbA1c level lower than 7.5% doubled. HbA1c increased again 2 months following the camp. The average blood glucose concentrations decreased in the last days of the camp when compared with the first day in three out of four daily measurements (P < 0.05). There were only two clinically manifested hypoglycaemia episodes recorded.

CONCLUSION

With a low rate of hypoglycaemia crisis and better glycemic control the proposed programme was found to be satisfactory but the downside was that the duration of the effects was too short. With no participation in organised exercise programmes and with absence of controlled nutrition, the beneficial effects of the camp disappeared within 2 months after the camp.

Physical activity, sport, and pediatric diabetes

The benefits derived from regular physical activity include improved cardiovascular fitness, increased lean mass, improved blood lipid profile, enhanced psychosocial well-being, and decreased body adiposity. The benefits for children with diabetes may also include blood glucose control and enhanced insulin sensitivity. However, for these children, engagement in vigorous physical activity and sport must be properly controlled through modifications in insulin therapy and nutritional intake so that the benefits of exercise outweigh the risks. The following review describes the various physiological and metabolic factors which occur both during exercise and during sport while describing specific recommendations to control glucose excursions by proper insulin management and diet.

Nocturnal hypoglycemia in patients with insulin-treated diabetes

While use of intensive insulin therapy has proven effective for reducing risk of long-term complications of hyperglycemia in people with diabetes, overnight hypoglycemia remains a significant barrier to intensive therapy. Findings from numerous studies indicate that nocturnal hypoglycemia is a frequent event among patients with type 1 diabetes, while severe hypoglycemic episodes are approximately three times more likely in patients on intensive insulin therapy than in those on conventional therapy. Nocturnal hypoglycemia remains frequent, even when specific approaches-use of short-acting insulin analogues to manage postprandial glucose surges, peakless long-acting insulin analogues as basal therapy, and strategically selected bedtime snacks-aim to avert this problem. Thus, nocturnal hypoglycemia continues to threaten the well-being of patients with diabetes and cause concerns for their family members and caregivers. Continuing research is required to improve methods for detection and prompt correction of hypoglycemia in order to achieve a safe level of euglycemia in people with diabetes.

Nocturnal hypoglycemia: clinical manifestations and therapeutic strategies toward prevention

OBJECTIVE

To review the features of nocturnal hypoglycemia and various preventive strategies.

METHODS

We discuss the physiologic changes, the potential precipitating factors, the immediate and long-term effects, and the currently available options for treatment of nocturnal hypoglycemia in patients with diabetes.

RESULTS

Nocturnal hypoglycemia is common in patients with type 1 diabetes and is usually asymptomatic. Nocturnal hyperinsulinemia frequently occurs with insulin therapy, and although blood glucose levels are often low during sleep, they are seldom measured routinely. Almost 50% of all episodes of severe hypoglycemia occur at night during sleep. Such episodes can cause convulsions and coma and have been implicated as a precipitating factor in cardiac arrhythmias resulting in sudden death--the "dead-in-bed syndrome." Nocturnal hypoglycemia seems to have no immediate detrimental effect on cognitive function; however, on the following day, mood and well-being may be adversely affected. Recurrent exposure to nocturnal hypoglycemia may impair cognitive function; other substantial long-term morbidity includes the development of acquired hypoglycemia syndromes, such as impaired awareness of hypoglycemia, through the putative effect of unsuspected recurrent episodes of nocturnal hypoglycemia.

CONCLUSION

In efforts to decrease the risk of nocturnal hypoglycemic episodes, various strategies can be used to minimize the nocturnal hyperinsulinemia that is associated with many insulin replacement regimens. Regular blood glucose monitoring (particularly at bedtime), the ingestion of appropriate bedtime snacks, and the utilization of short- and long-acting insulin analogues may all help to prevent or minimize the frequency of nocturnal hypoglycemia.

Hypoglycemia in Type 1 Diabetes Mellitus

Spontaneous hypoglycemia is uncommon in the general (nondiabetic) population, but iatrogenic hypoglycemia is rife in patients with type 1 diabetes mellitus, among whom hypoglycemia constitutes a barrier to optimal glycemic control. The obligate dependence on exogenous insulin, together with the current imperfection in insulin therapies, generates degrees of blood glucose fluctuations that often exceed physiological boundaries in these patients. Downward swings in blood glucose levels, if sustained, result in hypoglycemia and significant morbidity and mortality. Hypoglycemia in type 1 diabetes indicates an imbalance between caloric supply and glucose use in response to insulin or exercise. Counterregulatory mechanisms that auto-correct iatrogenic hypoglycemia often become progressively impaired in these patients. This defective counterregulation, together with the imperfections in insulin delivery, set the stage for significant morbidity from iatrogenic hypoglycemia. Recurrent episodes of iatrogenic hypoglycemia induce a state of hypoglycemia unawareness and defective counterregulation, which defines the syndrome of hypoglycemia-associated autonomic failure (HAAF). The reduced awareness of, and counterregulatory responses to, hypoglycemia in patients with HAAF lead to worsening episodes of severe hypoglycemia. Approaches to the prevention of hypoglycemia include glucose monitoring, patient education, meal planning, and medication adjustment. In patients with HAAF, scrupulous avoidance of iatrogenic hypoglycemia may restore the symptomatic and counterregulatory responses to hypoglycemia. Behavioral training focusing on recognition of the more subtle symptoms and signs of evolving hypoglycemia may be beneficial to some patients with HAAF. A methodical search for the pattern and etiology of iatrogenic hypoglycemia is a prerequisite for the identification of the best preventive approach. With proper education, patients with type 1 diabetes and their physicians can learn to prevent or minimize the risk of hypoglycemia while pursuing excellence in glycemic control.