Effect of varying glycemic index meals on blood glucose control assessed with continuous glucose monitoring in youth with type 1 diabetes on basal-bolus insulin regimens

What Is the Tech Missing? Nutrition Reporting in Type 1 Diabetes

INTRODUCTION

Type 1 Diabetes (T1D) presents self-management challenges, requiring an additional 180 daily decisions to regulate blood glucose (BG) levels. Despite the potential, T1D-focused applications have a 43% attrition rate. This work delves into the willingness of people living with T1D (PwT1D) to use technology.

METHOD

An online questionnaire investigated the current practices for carbohydrate estimation, nutritional tracking, and attitudes towards technology engagement, along with hypothetical scenarios and preferences regarding technology use.

RESULTS

Thirty-nine responses were collected from PwT1D (n = 33) and caregivers (n = 6). Nutrition reporting preferences varied, with 50% favoring 'type and scroll' while 30% preferred meal photographing. Concerning the timing of reporting, 33% reported before meals, 55% after, and 12% at a later time. Improved Time in Range (TIR) was a strong motivator for app use, with 78% expressing readiness to adjust insulin doses based on app suggestions for optimizing TIR. Meal descriptions varied; a single word was used in 42% of cases, 23% used a simple description (i.e., "Sunday dinner"), 30% included portion sizes, and 8% provided full recipes.

CONCLUSION

PwT1D shows interest in using technology to reduce the diabetes burden when it leads to an improved TIR. For such technology to be ecologically valid, it needs to strike a balance between requiring minimal user input and providing significant data, such as meal tags, to ensure accurate blood glucose management without overwhelming users with reporting tasks.

Improving the Edible and Nutritional Quality of Roasted Duck Breasts through Variable Pressure Salting: Implications for Protein Anabolism and Digestion in Rats

Variable pressure salting (VPS) is considered a novel salting approach to improve meat quality. This study aimed to investigate the effects of roasted duck's edible and nutritional quality after VPS through serum biochemical indicators and in vivo digestion properties in rats. The results show that roasted duck after VPS led to an increase in the total protein content (57.24 g/L) and blood glucose levels (6.87 mmol/L), as well as a decrease in the blood urea nitrogen content (11.81 mmol/L), in rats. Compared to rats fed base diets and roasted duck after static wet salting (SWS), those ingesting roasted duck after VPS exhibited higher values of apparent protein digestibility (51.24%), pepsin activity (2.40 U/mg), and trypsin activity (389.80 U/mg). Furthermore, VPS treatment improved the textural properties and microstructure of duck breasts shown by a higher immobilized water relaxation area and more ordered protein structures (α-helixes and β-sheets). These improvements enhanced the protein anabolism capacity and in vivo digestion properties in rats. Therefore, VPS represents a beneficial salting method for promoting effective digestion and absorption in rats.

The role of continuous glucose monitoring in physical activity and nutrition management: perspectives on present and possible uses

PURPOSE

Continuous glucose monitoring (CGM) is on the rise as the prevalence of obesity and diabetes increases. This review aimed to explore the use of CGM and its potential novel applications in physical activity and nutrition management.

METHODS

We searched PubMed, Web of Science, and Wiley Online Library databases using the keywords 'continuous glucose monitor,' 'nutrition,' 'physical activity,' and 'numerical modeling.'

RESULTS

Continuous blood glucose measurement is useful for individuals with obesity and diabetes. Long-term blood glucose data allow for personalized planning of nutritional composition, meal timing, and physical activity type and intensity, as well as help prevent hypoglycemia and hyperglycemia. Thus, understanding the limitations of CGM is important for its effective use.

CONCLUSION

CGM systems are being increasingly used to monitor and identify appropriate blood glucose controlling interventions. Blood glucose level is influenced by various factors such as nutrient composition, meal timing, physical activity, circadian rhythm, and cortisol levels. Numerical modeling can be used to analyze the complex relationship between stress, sleep, nutrition, and physical activity, which affect blood glucose levels. In future, blood glucose, sleep, and stress data will be integrated to predict appropriate lifestyle levels for blood glucose management. This integrated approach improves glucose control and overall wellbeing, potentially reducing societal costs.

Diet and Glycemic Index in Children with Type 1 Diabetes

In children with type 1 diabetes, a healthy lifestyle is important to control postprandial glycemia and to avoid hyperglycemic peaks that worsen the inflammatory state of vessels and tissues. Glycemic index and glycemic load are two important indexes which assess the quality and quantity of foods consumed during meals. The main macronutrients of the diet have a different effect on postprandial blood glucose levels, so it is important that diabetic children consume foods which determine a slower and steadier glycemic peak. In this review, we present the results of the most recent studies carried out in the pediatric population with T1D, whose aim was to analyze the effects of low-glycemic-index foods on glycemic control. The results are promising and demonstrate that diets promoting low-glycemic-index foods guarantee a greater glycemic stability with a reduction in postprandial hyperglycemic peaks. However, one of the main limitations is represented by the poor adherence of children to a healthy diet. In order to obtain satisfactory results, a possibility might be to ensure a balanced intake of low-, moderate- and high-glycemic-index foods, preferring those with a low glycemic index and limiting the consumption of the high- and moderate-glycemic-index types.

Super Bolus: a remedy for a high glycemic index meal in children with type 1 diabetes on insulin pump therapy?-study protocol for a randomized controlled trial

Background

Postprandial hyperglycemia (PPH) is a common clinical problem among patients with type 1 diabetes (T1D), which is related to high glycemic index (h-GI) meals. The main problem is linked to high, sharp glycemic spikes following hypoglycemia after h-GI meal consumption. There is a lack of effective and satisfactory solutions for insulin dose adjustment to cover an h-GI meal. The goal of this research was to determine whether a Super Bolus is an effective strategy to prevent PPH and late hypoglycemia after an h-GI meal compared to a Normal Bolus.

Methods

A total of 72 children aged 10–18 years with T1D for at least 1 year and treated with continuous subcutaneous insulin infusion for more than 3 months will be enrolled in a double-blind, randomized, crossover clinical trial. The participants will eat a h-GI breakfast for the two following days and receive a prandial insulin bolus in the form of a Super Bolus 1 day and a Normal Bolus the next day. The glucose level 90 min after the administration of the prandial bolus will be the primary outcome measure. The secondary endpoints will refer to the glucose levels at 30, 60, 120, 150, and 180 min postprandially, the area under the blood glucose curve within 180 min postprandially, peak glucose level and the time to peak glucose level, glycemic rise, the mean amplitude of glycemic excursions, and the number of hypoglycemia episodes.

Discussion

There are still few known clinical studies on this type of bolus. A Super Bolus is defined as a 50% increase in prandial insulin dose compared to the dose calculated based on the individualized patient’s insulin-carbohydrate ratio and a simultaneous suspension of basal insulin for 2 h. Our patients reported the best experience with such a combination. A comprehensive and effective solution to this frequent clinical difficulty of PPH after an h-GI meal has not yet been found. The problem is known and important, and the presented solution is innovative and easy to apply in everyday life.

Trial registration

ClinicalTrials.gov NCT04019821

Too Much Dietary Flexibility May Hinder, Not Help: Could More Specific Targets for Daily Food Intake Distribution Promote Glycemic Management among Youth with Type 1 Diabetes?

Average glycemic levels among youth with type 1 diabetes (T1D) have worsened in some parts of the world over the past decade despite simultaneous increased uptake of diabetes technology, thereby highlighting the persistent need to identify effective behavioral strategies to manage glycemia during this life stage. Nutrition is fundamental to T1D management. We reviewed the evidence base of eating strategies tested to date to improve glycemic levels among youth with T1D in order to identify promising directions for future research. No eating strategy tested among youth with T1D since the advent of flexible insulin regimens—including widely promoted carbohydrate counting and low glycemic index strategies—is robustly supported by the existing evidence base, which is characterized by few prospective studies, small study sample sizes, and lack of replication of results due to marked differences in study design or eating strategy tested. Further, focus on macronutrients or food groups without consideration of food intake distribution throughout the day or day-to-day consistency may partially underlie the lack of glycemic benefits observed in studies to date. Increased attention paid to these factors by future observational and experimental studies may facilitate identification of behavioral targets that increase glycemic predictability and management among youth with T1D.

Technological Ecological Momentary Assessment Tools to Study Type 1 Diabetes in Youth: Viewpoint of Methodologies

Type 1 diabetes (T1D) is one of the most common chronic childhood diseases, and its prevalence is rapidly increasing. The management of glucose in T1D is challenging, as youth must consider a myriad of factors when making diabetes care decisions. This task often leads to significant hyperglycemia, hypoglycemia, and glucose variability throughout the day, which have been associated with short- and long-term medical complications. At present, most of what is known about each of these complications and the health behaviors that may lead to them have been uncovered in the clinical setting or in laboratory-based research. However, the tools often used in these settings are limited in their ability to capture the dynamic behaviors, feelings, and physiological changes associated with T1D that fluctuate from moment to moment throughout the day. A better understanding of T1D in daily life could potentially aid in the development of interventions to improve diabetes care and mitigate the negative medical consequences associated with it. Therefore, there is a need to measure repeated, real-time, and real-world features of this disease in youth. This approach is known as ecological momentary assessment (EMA), and it has considerable advantages to in-lab research. Thus, this viewpoint aims to describe EMA tools that have been used to collect data in the daily lives of youth with T1D and discuss studies that explored the nuances of T1D in daily life using these methods. This viewpoint focuses on the following EMA methods: continuous glucose monitoring, actigraphy, ambulatory blood pressure monitoring, personal digital assistants, smartphones, and phone-based systems. The viewpoint also discusses the benefits of using EMA methods to collect important data that might not otherwise be collected in the laboratory and the limitations of each tool, future directions of the field, and possible clinical implications for their use.

The comparison of two mealtime insulin dosing algorithms for high and low glycaemic index meals in adolescents with type 1 diabetes

AIMS

Postprandial glycaemic variability carries on being a clinical challenge in optimizing glucose control in type 1 diabetes. The aim of this study was to compare the postprandial glycaemic effects of carbohydrate counting and food insulin index algorithms following the consumption of protein-rich, high-fat meals with different glycaemic index (GI) in adolescents with type 1 diabetes.

METHODS

A randomized, single-blind and crossover trial included 15 adolescents aged 14-18 years with type 1 diabetes. Participants consumed two different test meals with similar energy, macronutrients and food insulin index but the approximately twofold difference in GI, in random order on four consecutive mornings at their home. Insulin dose for high- and low-GI test meals was determined by using the carbohydrate counting and food insulin index algorithms. Four-hour postprandial glycaemia was assessed by the continuous glucose monitoring system.

RESULTS

Compared with carbohydrate counting, the food insulin index algorithm significantly decreased peak glucose excursion (-57%, p = 0.02), incremental area under the curve (-65%, p = 0.02) and coefficient variation of blood glucose (-37%, p = 0.03) in the high-GI meal, though there was no difference between the two algorithms in the low-GI meal. The occurrence of hypoglycaemia did not significantly differ between insulin dosing algorithms for the high-GI (p = 0.58) and low-GI (p = 0.20) meals.

CONCLUSIONS

The food insulin index algorithm may be beneficial for postprandial glycaemic control after the consumption of high-GI meals in adolescents with type 1 diabetes.

Evaluation of the Effect of Macronutrients Combination on Blood Sugar Levels in Healthy Individuals

BACKGROUND

The positive effects of blood glucose levels should be demonstrated in healthy or type 2 diabetic individuals who can be recommended to consume macronutrients (protein + fat) with carbohydrates. Therefore, at the end of the research planned with the amount of carbohydrates and fats that can be consumed in a meal, we aimed to recommend the consumption of food with high protein content egg together with the carbohydrate source.

METHODS

The study was carried out from Nov 2017 to Apr 2018 by looking at fasting blood glucose levels using feeding 2 different test foods on a minimum of 8 h of fasting in the Haliç University Sutluce Campus, Istanbul, Turkey. Before and after the carbohydrate and carbohydrate + protein source, blood glucose was measured from the fingertip for 3 days in 30 min, 60 min and 120 min periods. The average of 3 days was used in the analysis.

RESULTS

Blood glucose values were compared after individuals were given carbohydrate and carbohydrate + protein source. The mean blood glucose value 60 min after the carbohydrate administration was significantly higher than the average blood glucose value 60 min after the carbohydrate + protein administration (P= 0.006).

CONCLUSION

A protein-containing diet positively affects the glycemia response and can recommend it. In individuals with diabetes, they should focus on the effects of proteins to achieve glycemia control.

Factors Influencing Adherence Among Youth with Type-1-Diabetes Mellitus - The Hungarian Case

Background and Introduction: Due to the increasing prevalence of type-1-diabetes, an increasing number of studies have drawn attention to its psychological effects and long-term consequences. As Type 1 Diabetes Mellitus is a chronic, non-curable, yet maintainable condition, with the affected children and their families facing a lifelong challenge, our research focuses on the factors influencing adherence.

METHODS

The adherence of youth was examined in a sample involving 114 patients treated in the Medical and Health Science Centre at the University of Debrecen by employing a new adherence questionnaire (DAQ abbreviated version, Munkácsi et al. 2019) (DAF 2017; N=114). The influence of socio- demographic variables and those related to the disease (age at the time of diagnosis, the time elapsed since diagnosis, method of treatment, the time elapsed since the use of the pump) was measured by linear regression. Furthermore, the between-group comparisons were made by independent sample t-tests and variance analysis. The investigation was carried out between September 2017 and May 2018.

RESULTS

The effect of using insulin pump as therapy turned out to be significant and positive (0.36. p=0.045). It was observed that the adherence of the patients using insulin pump was higher while the effect of the age at the diagnosis had a significantly negative effect (-.247, p=0.035). Thus, earlier detection of the disease may lead to a higher level of adherence. The effects of the socio-demographic variables (gender, family structure, educational level, type of the settlement, owning sibling and birth order) were not significant (p>0.05). Regarding the between-group comparisons, a significant difference could be pointed out concerning the siblings and birth-order as the adherence of those with siblings was higher (p=0.044). Moreover, concerning insulin pump therapy, the adherence of patients using pump was significantly better (p=0.048). Also, regarding the age of the diagnosis, the adherence of those diagnosed before 12 was seemingly higher (p=0.039). Concerning the other socio-demographical and disease-related variables, no significant differences could be detected.

CONCLUSION

The results suggest that the treatment has an outstanding role in the adherence of the disease. Moreover, the role of the appropriate treatment, living conditions as well as the early diagnosis is relevant.

Carbohydrate Intake in the Context of Exercise in People with Type 1 Diabetes

Although the benefits of regular exercise on cardiovascular risk factors are well established for people with type 1 diabetes (T1D), glycemic control remains a challenge during exercise. Carbohydrate consumption to fuel the exercise bout and/or for hypoglycemia prevention is an important cornerstone to maintain performance and avoid hypoglycemia. The main strategies pertinent to carbohydrate supplementation in the context of exercise cover three aspects: the amount of carbohydrates ingested (i.e., quantity in relation to demands to fuel exercise and avoid hypoglycemia), the timing of the intake (before, during and after the exercise, as well as circadian factors), and the quality of the carbohydrates (encompassing differing carbohydrate types, as well as the context within a meal and the associated macronutrients). The aim of this review is to comprehensively summarize the literature on carbohydrate intake in the context of exercise in people with T1D.

Postprandial Glucose Control in Type 1 Diabetes: Importance of the Gastric Emptying Rate

The achievement of optimal post-prandial (PP) glucose control in patients with type 1 diabetes (T1DM) remains a great challenge. This review summarizes the main factors contributing to PP glucose response and discusses the likely reasons why PP glucose control is rarely achieved in T1DM patients. The macronutrient composition of the meal, the rate of gastric emptying and premeal insulin administration are key factors affecting the PP glucose response in T1DM. Although the use of continuous insulin infusion systems has improved PP glucose control compared to conventional insulin therapy, there is still need for further ameliorations. T1DM patients frequently present a delayed gastric emptying (GE) that produces a lower but more prolonged PP hyperglycemia. In addition, delayed GE is associated with a longer time to reach the glycemic peak, with a consequent mismatch between PP glucose elevation and the timing of premeal insulin action. On this basis, including GE time and meal composition in the algorithms for insulin bolus calculation of the insulin delivery systems could be an important step forward for optimization of PP glucose control in T1DM.

Insulin in Type 1 and Type 2 Diabetes-Should the Dose of Insulin Before a Meal be Based on Glycemia or Meal Content?

The aim of this review was to investigate existing guidelines and scientific evidence on determining insulin dosage in people with type 1 and type 2 diabetes, and in particular to check whether the prandial insulin dose should be calculated based on glycemia or the meal composition, including the carbohydrates, protein and fat content in a meal. By exploring the effect of the meal composition on postprandial glycemia we demonstrated that several factors may influence the increase in glycemia after the meal, which creates significant practical difficulties in determining the appropriate prandial insulin dose. Then we reviewed effects of the existing insulin therapy regimens on glycemic control. We demonstrated that in most existing algorithms aimed at calculating prandial insulin doses in type 1 diabetes only carbohydrates are counted, whereas in type 2 diabetes the meal content is often not taken into consideration. We conclude that prandial insulin doses in treatment of people with diabetes should take into account the pre-meal glycemia as well as the size and composition of meals. However, there are still open questions regarding the optimal way to adjust a prandial insulin dose to a meal and the possible benefits for people with type 1 and type 2 diabetes if particular parameters of the meal are taken into account while calculating the prandial insulin dose. The answers to these questions may vary depending on the type of diabetes.

Targeting postprandial glycaemia in children with diabetes: Opportunities and challenges

Postprandial glycaemia makes a substantial contribution to overall glycaemic control in diabetes, particularly in patients whose preprandial glycaemia is relatively well controlled and glycated haemoglobin (HbA1c) only modestly elevated. Our review addresses the determinants of postprandial glycaemia and how it may be targeted therapeutically in children with diabetes. Postprandial glycaemia is influenced by preprandial glycaemia, macronutrients and their absorption, insulin delivery and sensitivity, the action of the enteroendocrine system, and the rate of gastric emptying. Contemporary continuous glucose monitoring systems reveal patterns of post prandial glycaemia and allow management to be guided more precisely. Delays in blood glucose determination, insulin delivery and its absorption remain challenges in the rapidly evolving closed loop continuous subcutaneous insulin and glucagon delivery systems developed for children with type 1 diabetes. Augmentation of the incretin system through nutritional preloads or incretin mimetics targets postprandial glycaemia by slowing gastric emptying as well as insulinotropic and glucagonostatic effects. These treatments are of particular relevance to children with type 2 diabetes. Following the development of targeted therapies in adults, postprandial blood glucose control will now be increasingly targeted in the treatment of diabetes in children.

Dietary intake and risk of non-severe hypoglycemia in adolescents with type 1 diabetes

AIMS

To determine the association between dietary intake and risk of non-severe hypoglycemia in adolescents with type 1 diabetes.

METHODS

Type 1 adolescents from a randomized trial wore a blinded continuous glucose monitoring (CGM) system at baseline for one week in free-living conditions. Dietary intake was calculated as the average from two 24-h dietary recalls. Non-severe hypoglycemia was defined as having blood glucose <70mg/dL for ≥10min but not requiring external assistance, categorized as daytime and nocturnal (11PM-7AM). Data were analyzed using logistic regression models.

RESULTS

Among 98 participants with 14,277h of CGM data, 70 had daytime hypoglycemia, 66 had nocturnal hypoglycemia, 55 had both, and 17 had neither. Soluble fiber and protein intake were positively associated with both daytime and nocturnal hypoglycemia. Glycemic index, monounsaturated fat, and polyunsaturated fat were negatively associated with daytime hypoglycemia only. Adjusting for total daily insulin dose per kilogram eliminated all associations.

CONCLUSIONS

Dietary intake was differentially associated with daytime and nocturnal hypoglycemia. Over 80% of type 1 adolescents had hypoglycemia in a week, which may be attributed to the mismatch between optimal insulin dose needed for each meal and actually delivered insulin dose without considering quality of carbohydrate and nutrients beyond carbohydrate.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT01286350.

Does the ingestion of a 24 hour low glycaemic index Asian mixed meal diet improve glycaemic response and promote fat oxidation? A controlled, randomized cross-over study

BACKGROUND

The health benefits of consuming a low glycaemic index (GI) diet to reduce the risk of type 2 Diabetes are well recognized. In recent years the GI values of various foods have been determined. Their efficacy in constructing and consuming a low GI diet over 24 h in modulating glycaemic response has not been fully documented. The translation of using single-point GI values of foods to develop a 24 h mixed meal diet can provide valuable information to consumers, researchers and dietitians to optimize food choice for glycaemic control. By using GI values of foods to develop mixed meals, our study is the first to determine how both blood glucose and substrate oxidation may be modulated over 24 h.

METHODS

The study included 11 Asian men with a BMI between 17-24 kg/m² who followed both a 1-day low GI and 1-day high GI diet in a randomized, controlled cross-over design. Test meals included breakfast, lunch, snack and dinner. Glycaemic response was measured continuously for over 24 h and postprandial substrate oxidation for 10 h inside a whole body calorimeter.

RESULTS

The low GI diet resulted in lower 24 h glucose iAUC (860 ± 440 vs 1329 ± 614 mmol/L.min; p = 0.014) with lower postprandial glucose iAUC after breakfast (p < 0.001), lunch (p = 0.009), snack (p = 0.012) and dinner (p = 0.003). Moreover, 24 h mean amplitude of glycaemic excursion was lower during the low GI vs high GI diet (1.44 ± 0.63 vs 2.33 ± 0.82 mmol/L; p < 0.001). Simultaneously, decrease in 10 h fat oxidation was less during the low vs high GI diet (-0.033 ± 0.021 vs -0.050 ± 0.017 g/min; p < 0.001), specifically after breakfast (p < 0.001) and lunch (p < 0.001).

CONCLUSIONS

Our study corroborates that using low GI local foods to construct a 24 h low GI diet, is able to reduce glycaemic response and variability as recorded by continuous glucose monitoring. Our observations also confirm that a low GI diet promotes fat oxidation over carbohydrate oxidation when compared to a high GI diet. These observations provide public health support for the encouragement of healthier nutrition choices by consuming low GI foods.

TRIAL REGISTRATION

NCT 02631083 (Clinicaltrials.gov).

Effect of high and low glycemic index breakfast on postprandial metabolic parameters and satiety in subjects with type 2 diabetes mellitus under intensive insulin therapy: Controlled clinical trial

BACKGROUND AND AIM

The results of studies evaluating the metabolic effects of glycemic index (GI) in subjects with type 2 diabetes mellitus (DM2) have been contradictory. Consequently, the benefits of its application are controversial and polarized opinions of international organizations have been disclosed. The above situation leads this study to evaluate the acute effect of low and high GI breakfast on the glycemic response and satiety in subjects with DM2 under intensive insulin therapy (IIT).

METHODS

A controlled, crossover and single-blind clinical trial was developed involving 10 obese subjects with DM2 under IIT, with a period of at least six months under IIT and with fast insulin prescription before breakfast. Subjects ingested on two different occasions a high or low GI breakfast. In both stages, glycemia was evaluated at 0 (basal), 30, 60 and 120 min, and satiety and satiation were evaluated through a visual analogue scale.

RESULTS

In contrast to high GI breakfast, the low GI meal generated a significant decrease of 46% for the area under the curve of glucose (Δ 1940 mg/dL × 120 min, p = 0.022) and in mean glycemia evaluated at 30, 60 and 120 min. Moreover, in the low GI stage 8 of 10 patients achieved a 2 h postprandial glycemia lower than 180 mg/dL, without statistical significance. A nonsignificant increase of 12.7% (Δ 1.06 cm, p = 0.271) in satiety at 120 min in the low GI stage was observed.

CONCLUSION

In contrast to high GI breakfast, the low GI breakfast generated a significantly lower glycemic response. This assay allowed for the contribution of more in depth nutritional recommendations for this group of patients. Registered under ClinicalTrials.gov Identifier no. NCT02881164.

Greater postprandial glucose excursions and inadequate nutrient intake in youth with type 1 diabetes and celiac disease

The gluten free diet (GFD) has a high glycemic index and low-fiber content, which potentially influences glycemic excursions in type 1 diabetes (T1D) and celiac disease (CD). Participants in this case-control study of youth with T1D+CD (n = 10) and T1D only (n = 7) wore blinded continuous glucose monitoring systems for six days. Blood glucose levels (BGLs) were compared between groups for each meal, including pre-meal, peak, 2-hour postprandial and time-to-peak. Participants consumed a test-breakfast of GF cereal and milk for three days and kept weighed food diaries; nutrient intake was analyzed and compared to national recommendations. Youth with T1D+CD had shorter time-to-peak BGL (77 vs 89 mins, P = 0.03), higher peak (9.3 vs 7.3 mmol/L, P = 0.001) and higher postprandial BGLs than T1D (8.4 vs 7.0 mmol/L, P = 0.01), despite similar pre-meal BGLs (9.2 vs 8.6 mmol/L, P = 0.28). Regarding test breakfast, greater pre and post-meal BGL difference correlated with longer CD duration (R = 0.53, P = 0.01). Total energy and macronutrient intake didn’t differ between groups; however the majority of participants collectively had inadequate intake of calcium (76%), folate (71%) and fiber (53%), with excessive saturated fat (12%) and sodium (>2,000 mg/day). The GFD is associated with greater glycemic excursions and inadequate nutritional intake in youth with T1D+CD. Clinical management should address both glycemic variability and dietary quality.

Effects of the dietary approaches to stop hypertension (DASH) diet on glucose variability in youth with Type 1 diabetes

Objective

Glucose variability (GV) independently increases risk for vascular events in patients with diabetes. The Dietary Approaches to Stop Hypertension (DASH) dietary pattern emphasizes fruits, vegetables, whole grains, lean meats, and low fat dairy and has the potential to reduce postprandial blood glucose (BG) excursions, however, its effect on GV is not known. The purpose of this work was to assess feasibility and collect preliminary data on the efficacy of the DASH diet on GV in adolescents with type 1 diabetes (T1D).

Methods

Twenty one adolescents recruited from the Diabetes Center of Cincinnati Children's Hospital Medical Center with T1D (11-17y) participated in one of two phases of a controlled feeding study. The first phase tested the acceptability and blood glucose response to a traditional DASH diet (DASH) and the second phase tested a DASH diet specifically modified for diabetes (DASH-D) to improve glucose response to meals. For each phase, participants consumed first their usual diet, and then a controlled DASH diet while wearing continuous glucose monitoring (CGM) systems for 3 days of each diet. All foods were provided to the patients during the DASH dietary periods and 24 h dietary recalls were conducted during the usual diet periods to assess daily intake.

Results

Sixteen participants (14.1 +/- 2.2y) were included in final analyses (DASH n=7, DASH-D n=9). Both DASH diets were significantly higher in fruits, vegetables, fiber, vitamin A, and % energy from protein than usual intakes. DASH was higher in carbohydrate (CHO) (60 vs. 50%) and lower in fat (21 vs. 36%) than usual intake, resulting in higher GV (Standard Deviation and Lability Index) and more low BG excursions (3 ± 2.8 vs. 7.1 ± 3.3, p=0.024). DASH-D was modified to better match CHO and fat content of patients' usual intakes in phase 1 (50/30/20 for CHO/fat/pro respectively, which resulted in no difference in GV between DASH-D and usual intake. There were also trends for lower average BG (144.1 vs. 168.9, p=0.072) and less percentage of time spent in the hyperglycemic range (39.3 ± 25.5 vs. 54.1 ± 19.4, p=0.07) on DASH-D compared to usual intake.

Conclusion

The DASH dietary pattern tended to result in less hyperglycemia and an overall lower BG compared to usual care. Modifying a traditional DASH diet by increasing heart healthy fats improves glycemic response to DASH and may be beneficial for long term cardiovascular benefits in youth with T1D.

Lower glycemic load meals reduce diurnal glycemic oscillations in women with risk factors for gestational diabetes

OBJECTIVE

Maternal glycemia plays a key role in fetal growth. We hypothesized that lower glycemic load (GL) meals (lower glycemic index, modestly lower carbohydrate) would substantially reduce day-long glucose variability in women at risk of gestational diabetes mellitus (GDM).

RESEARCH DESIGN AND METHODS

A crossover study of 17 women (mean±SD age 34.8±4 years; gestational weeks 29.3±1.3; body mass index 23.8±4.7 kg/m²) who consumed a low GL or a high GL diet in random order, 1-day each, over 2 consecutive days. Diets were energy-matched and fiber-matched with 5 meals per 24 hours. All food was provided. Continuous glucose monitoring was used to assess diurnal glycemia.

RESULTS

Maternal glucose levels were 51% lower on the low GL day with lower incremental area under the curve (iAUC±SEM 549±109 vs 1120±198 mmol/L min, p=0.015). Glycemic variability was significantly lower on the low GL day, as demonstrated by a lower average SD (0.7±0.1 vs 0.9±0.1, p<0.001) and lower mean amplitude of glycemic excursions (2.1±0.2 vs 2.7±0.2 mmol/L, p<0.001).

CONCLUSIONS

A lower GL meal plan in pregnancy acutely halves day-long maternal glucose levels and reduces glucose variability, providing further evidence to support the utility of a low GL diet in pregnancy.

Nutrition in Diabetes

Medical nutrition therapy (MNT) is a key component of diabetes management. The importance of balancing macronutrients, reducing carbohydrate load, lowering glycemic index, and implementing an overall healthy dietary pattern are emerging as better approaches for MNT in diabetes. Recent research points to improved glycemic control, reduction in body weight, and improvement in many cardiovascular risk factors when these approaches are provided by registered dietitians or health care providers. This review article discusses the current evidence about the role of sensible nutrition in diabetes management. Specific eating plans for weight reduction and for patients with type 1 diabetes are also discussed.

Greater diet quality is associated with more optimal glycemic control in a longitudinal study of youth with type 1 diabetes

BACKGROUND

Despite the centrality of nutrition in the management of type 1 diabetes, the association of diet quality and macronutrient distribution with glycemic control is ambiguous.

OBJECTIVE

This study examined longitudinally the association of dietary intake with multiple indicators of glycemic control in youth with type 1 diabetes participating in a behavioral nutrition intervention study.

DESIGN

Participants in a randomized clinical trial of a behavioral nutrition intervention [n = 136; mean ± SD age: 12.8 ± 2.6 y; glycated hemoglobin (HbA1c): 8.1% ± 1.0%; 69.1% using an insulin pump] completed 3-d diet records at baseline and months 3, 6, 9, 12, and 18; masked continuous glucose monitoring (CGM) data were obtained concurrently with the use of the Medtronic iPro CGM system. HbA1c was obtained every 3 mo; 1,5-anhydroglucitol was obtained every 6 mo. Linear mixed-effects regression models estimated associations of time-varying dietary intake variables with time-varying glycemic control indicators, controlling for age, height, weight, sex, Tanner stage, diabetes duration, regimen, frequency of blood glucose monitoring, physical activity, and treatment assignment.

RESULTS

HbA1c was associated inversely with carbohydrate and natural sugar, and positively with protein and unsaturated fat. 1,5-Anhydroglucitol was associated positively with fiber intake and natural sugar. Greater glycemic control as indicated by ≥1 CGM variable was associated with higher Healthy Eating Index-2005, whole plant food density, fiber, carbohydrate, and natural sugar and lower glycemic index and unsaturated fat.

CONCLUSIONS

Both overall diet quality and macronutrient distribution were associated with more optimal glycemic control. Associations were more consistent for CGM variables obtained concurrently with dietary intake than for biomarkers of longer-term glycemic control. These findings suggest that glycemic control may be improved by increasing intake of high-fiber, low glycemic-index, carbohydrate-containing foods. This trial was registered at clinicaltrials.gov as NCT00999375.

Impact of fat, protein, and glycemic index on postprandial glucose control in type 1 diabetes: implications for intensive diabetes management in the continuous glucose monitoring era

BACKGROUND

Continuous glucose monitoring highlights the complexity of postprandial glucose patterns present in type 1 diabetes and points to the limitations of current approaches to mealtime insulin dosing based primarily on carbohydrate counting.

METHODS

A systematic review of all relevant biomedical databases, including MEDLINE, Embase, CINAHL, and the Cochrane Central Register of Controlled Trials, was conducted to identify research on the effects of dietary fat, protein, and glycemic index (GI) on acute postprandial glucose control in type 1 diabetes and prandial insulin dosing strategies for these dietary factors.

RESULTS

All studies examining the effect of fat (n = 7), protein (n = 7), and GI (n = 7) indicated that these dietary factors modify postprandial glycemia. Late postprandial hyperglycemia was the predominant effect of dietary fat; however, in some studies, glucose concentrations were reduced in the first 2-3 h, possibly due to delayed gastric emptying. Ten studies examining insulin bolus dose and delivery patterns required for high-fat and/or high-protein meals were identified. Because of methodological differences and limitations in experimental design, study findings were inconsistent regarding optimal bolus delivery pattern; however, the studies indicated that high-fat/protein meals require more insulin than lower-fat/protein meals with identical carbohydrate content.

CONCLUSIONS

These studies have important implications for clinical practice and patient education and point to the need for research focused on the development of new insulin dosing algorithms based on meal composition rather than on carbohydrate content alone.

Improving dietary quality in youth with type 1 diabetes: randomized clinical trial of a family-based behavioral intervention

Background

Diets of children with type 1 diabetes are low in fruits, vegetables, and whole grains, and high in foods of minimal nutritional value, increasing risk for future adverse health outcomes. This 18-month randomized clinical trial tested the effect of a family-based behavioral intervention integrating motivational interviewing, active learning, and applied problem-solving on the primary outcomes of dietary intake and glycemic control among youth with type 1 diabetes.

Methods

A parallel-group study with equal randomization was conducted at an outpatient, free-standing, multidisciplinary tertiary diabetes center in the United States. Eligible youth were those age 8–16 years with type 1 diabetes diagnosis ≥1 year and hemoglobin A1c (HbA1c) ≥6.5% and ≤10.0%. Participants were 136 parent-youth dyads (treatment n = 66, control n = 70). The intervention consisted of 9 in-clinic sessions delivered to the child and parent; control condition comprised equivalent assessments and number of contacts without dietary advice. Dietary intake was assessed using 3-day diet records at 6 time points across the 18-month study. Dietary outcomes included the Healthy Eating Index-2005 (HEI2005; index measuring conformance to the 2005 United States Dietary Guidelines for Americans) and Whole Plant Food Density (WPFD; number of cup or ounce equivalents per 1000 kcal of whole grains, whole fruit, vegetables, legumes, nuts, and seeds consumed). HbA1c was obtained every 3 months. Overall comparison of outcome variables between intervention and usual care groups was conducted using permutation tests.

Results

There was a positive intervention effect across the study duration for HEI2005 (p = .015) and WPFD (p = .004). At 18 months, HEI2005 was 7.2 greater (mean ± SE 64.6 ± 2.0 versus 57.4 ± 1.6), and WPFD was 0.5 greater (2.2 ± 0.1 versus 1.7 ± 0.1) in the intervention group versus control. There was no difference between groups in HbA1c across the study duration.

Conclusions

This behavioral nutrition intervention improved dietary quality among youth with type 1 diabetes, but did not impact glycemic control. Findings indicate the potential utility of incorporating such strategies into clinical care, and suggest that improvement in diet quality can be achieved in families living with this burdensome disease.

Trial registration

Clinicaltrials.gov registration number: NCT00999375

Electronic supplementary material

The online version of this article (doi:10.1186/s12966-015-0214-4) contains supplementary material, which is available to authorized users.

Contextual factors are associated with diet quality in youth with type 1 diabetes mellitus

This study examined differences in diet quality by meal type, location, and time of week in youth with type 1 diabetes mellitus. A sample of youth with type 1 diabetes mellitus (n=252; 48% female) age 8 to 18 years (mean±standard deviation=13.2±2.8 years) with diabetes duration ≥1 year (mean±standard deviation=6.3±3.4 years) completed 3-day diet records. Multilevel linear regression models tested for differences in diet quality indicators by meal type, location, and time of week (weekdays vs weekends). Participants showed greater energy intake and poorer diet quality on weekends relative to weekdays, with lower intake of fruit and vegetables, and higher intake of total and saturated fat. Differences in diet quality were seen across meal types, with higher nutrient density at breakfast and dinner than at lunch and snacks. Participants reported the highest whole-grain and lowest fat intake at breakfast, but higher added sugar than at lunch or dinner. Dinner was characterized by the highest fruit intake, lowest added sugar, and lowest glycemic load, but also the highest sodium intake. The poorest nutrient density and highest added sugar occurred during snacks. Diet quality was poorer for meals consumed away from home than those consumed at home for breakfast, dinner, and snacks. Findings regarding lunch meal location were mixed, with higher nutrient density, lower glycemic load, and less added sugar at home lunches, and lower total fat, saturated fat, and sodium at lunches away from home. Findings indicate impacts of meal type, location, and time of week on diet quality, suggesting targets for nutrition education and behavioral interventions.

A low-glycemic index meal and bedtime snack prevents postprandial hyperglycemia and associated rises in inflammatory markers, providing protection from early but not late nocturnal hypoglycemia following evening exercise in type 1 diabetes

OBJECTIVE

To examine the influence of the glycemic index (GI) of foods consumed after evening exercise on postprandial glycemia, metabolic and inflammatory markers, and nocturnal glycemic control in type 1 diabetes.

RESEARCH DESIGN AND METHODS

On two evenings (∼1700 h), 10 male patients (27 ± 5 years of age, HbA1c 6.7 ± 0.7% [49.9 ± 8.1 mmol/mol]) were administered a 25% rapid-acting insulin dose with a carbohydrate bolus 60 min before 45 min of treadmill running. At 60 min postexercise, patients were administered a 50% rapid-acting insulin dose with one of two isoenergetic meals (1.0 g carbohdyrate/kg body mass [BM]) matched for macronutrient content but of either low GI (LGI) or high GI (HGI). At 180 min postmeal, the LGI group ingested an LGI snack and the HGI group an HGI snack (0.4 g carbohdyrate/kg BM) before returning home (∼2300 h). Interval samples were analyzed for blood glucose and lactate; plasma glucagon, epinephrine, interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α); and serum insulin, cortisol, nonesterified fatty acid, and β-hydroxybutyrate concentrations. Interstitial glucose was recorded for 20 h postlaboratory attendance through continuous glucose monitoring.

RESULTS

Following the postexercise meal, an HGI snack induced hyperglycemia in all patients (mean ± SD glucose 13.5 ± 3.3 mmol/L) and marked increases in TNF-α and IL-6, whereas relative euglycemia was maintained with an LGI snack (7.7 ± 2.5 mmol/L, P < 0.001) without inflammatory cytokine elevation. Both meal types protected all patients from early hypoglycemia. Overnight glycemia was comparable, with a similar incidence of nocturnal hypoglycemia (n = 5 for both HGI and LGI).

CONCLUSIONS

Consuming LGI food with a reduced rapid-acting insulin dose following evening exercise prevents postprandial hyperglycemia and inflammation and provides hypoglycemia protection for ∼8 h postexercise; however, the risk of late nocturnal hypoglycemia remains.

Relationships among parent and youth healthful eating attitudes and youth dietary intake in a cross-sectional study of youth with type 1 diabetes

Background

Constructs based on Social Cognitive Theory have shown utility in understanding dietary behavior; however, little research has examined these relations in youth and parents concurrently. Unique demands of dietary management among families of youth with type 1 diabetes (T1D) suggest the importance of investigation in this population. The purpose of this study was to develop and evaluate youth and parent measures of self-efficacy, outcome expectations, and barriers for healthful eating, and parent modeling of healthful eating, in a sample of youth with type 1 diabetes and their parents.

Methods

Youth (n=252) ages 8–18 years with diabetes duration ≥1 year and parents completed self-report measures of healthful eating attitudes including self-efficacy, perceived barriers, positive and negative outcome expectations; youth reported parent modeling of healthful eating. Youth dietary intake from 3-day diet records was used to calculate the Healthy Eating Index 2005 and the Nutrient Rich Foods 9.3 index, measures of overall diet quality. The relations among parent and youth healthful eating attitudes, parent modeling, and youth diet quality were examined using structural equation modeling.

Results

Internal consistency and test-retest reliability of the measures were acceptable. The structural equation model demonstrated acceptable fit (CFI/TLI=0.94/0.94; RMSEA=0.03), and items loaded the hypothesized factors. Parent modeling β^=.27,p=.02 and attitudes toward healthful eating (latent variable comprised of self-efficacy, barriers, outcome expectations) β^=.16,p=.04 had direct effects on youth diet quality. Parent modeling had a direct effect on youth attitudes β^=.49,p<.001; parent attitudes had an indirect effect on youth attitudes through parent modeling β^=.12,p,<.001. Youth attitudes were not associated with youth diet quality. Overall, the model accounted for 20% of the variance in child diet quality.

Conclusions

Parent diet-related behaviors demonstrated an impact on youth attitudes and diet quality, suggesting the importance of family-based clinical and public health efforts to improve diet.

Effect of consumption of micronutrient enriched wheat steamed bread on postprandial plasma glucose in healthy and type 2 diabetic subjects

BACKGROUND

Steamed wheat bread have previously been shown to induce comparatively high postprandial plasma glucose responses, on the contrary, buckwheat products induced lower postprandial plasma glucose. The present study was to assess the effects of micronutrient enriched bread wheat variety Jizi439 and buckwheat on postprandial plasma glucose in healthy and diabetic subjects comparing with buckwheat and other bread wheat varieties.

METHODS

Two experiments were conducted to study the effects of bread wheat variety Jizi439 on the postprandial plasma glucose levels of the randomly selected subjects. The first experiment involved three types of steamed bread with equivalent of 50 g available carbohydrate fed to 10 normal weight young healthy subjects. Two types of steamed bread were made from two purple-grain bread wheat varieties, Jizi439 and Chu20, respectively, and the third type was made from the mixture of different white grain wheat varieties. Plasma glucose levels of each subject were measured at 15, 30, 45, 60, 120 min after eating. Glucose was used as a reference, the total area under curve (AUC) and glycemic index (GI) was calculated for test meal. The second experiment was performed among ten type 2 diabetics who were served equivalent of 50 g available carbohydrate of steamed bread made from Jizi 439, the mixture of white grain bread wheat and buckwheat, respectively. The plasma glucose increment was determined two hours thereafter.

RESULTS

In the first experiment, consumption of the steamed bread made from Jizi439 resulted in the least increase in plasma glucose and the GI was significantly lower than that of Chu20 and the mixture. In the second experiment, the average of postprandial 2 h plasma glucose increment of Jizi439 was 2.46 mmol/L which was significantly lower than that of the mixture of white wheat but was not significantly different from buckwheat.

CONCLUSIONS

The results indicated that consumption of Jizi439 steamed bread resulted in significantly lower plasma glucose in both healthy and diabetic subjects, compared with other types of test foods, except buckwheat bread. The steam bread made from Jizi439 would be an ideal food for preventing and treatment of diabetes.

Effect of a low glycaemic index diet in gestational diabetes mellitus on post-natal outcomes after 3 months of birth: a pilot follow-up study

A low glycaemic index (LGI) diet during pregnancy complicated by gestational diabetes mellitus (GDM) may offer benefits to the mother and infant pair beyond those during pregnancy. We aimed to investigate the effect of an LGI diet during pregnancy complicated with GDM on early post-natal outcomes. Fifty-eight women (age: 23-41 years; mean ± SD pre-pregnancy body mass index: 24.5 ± 5.6 kg m(-2) ) who had GDM and followed either an LGI diet (n = 33) or a conventional high-fibre diet (HF; n = 25) during pregnancy had a 75-g oral glucose tolerance test and blood lipid tests at 3 months post-partum. Anthropometric assessments were conducted for 55 mother-infant pairs. The glycaemic index of the antenatal diets differed modestly (mean ± SD: 46.8 ± 5.4 vs. 52.4 ± 4.4; P < 0.001), but there were no significant differences in any of the post-natal outcomes. In conclusion, an LGI diet during pregnancy complicated by GDM has outcomes similar to those of a conventional healthy diet. Adequately powered studies should explore the potential beneficial effects of LGI diet on risk factors for chronic disease.

Multiple indicators of poor diet quality in children and adolescents with type 1 diabetes are associated with higher body mass index percentile but not glycemic control

BACKGROUND

Diet is a cornerstone of type 1 diabetes treatment, and poor diet quality may affect glycemic control and other health outcomes. Yet diet quality in children and adolescents with type 1 diabetes remains understudied.

OBJECTIVE

To evaluate multiple indicators of diet quality in children and adolescents with type 1 diabetes and their associations with hemoglobin A1c and body mass index percentile.

DESIGN

In this cross-sectional study, participants completed 3-day diet records, and data were abstracted from participants' medical records. Diet quality indicators included servings of fruit, vegetables, and whole grains; Healthy Eating Index-2005 (HEI-2005) score; Nutrient Rich Foods 9.3 score (NRF 9.3); and glycemic index.

PARTICIPANTS/SETTING

Children and adolescents with type 1 diabetes ≥ 1 year, aged 8 to 18 years, were recruited at routine clinic visits. Of 291 families enrolled, 252 provided diet data.

STATISTICAL ANALYSES

Associations of diet quality indicators to HbA1c and body mass index percentile were examined using analysis of covariance and multiple linear regression.

RESULTS

Participants demonstrated low adherence to dietary guidelines; mean HEI-2005 score was 53.4 ± 11.0 (range = 26.7 to 81.2). Intake of fruit, vegetables, and whole grains was less than half the recommended amount. Almost half of the participants' daily energy intake was derived from refined-grain products, desserts, chips, and sweetened beverages. Higher fruit (P = 0.04) and whole-grain (P = 0.03) intake were associated with lower HbA1c in unadjusted, but not adjusted analyses; vegetable intake, HEI-2005 score, NRF 9.3 score, and glycemic index were not associated with HbA1c. Higher fruit (P = 0.01) and whole-grain (P = 0.04) intake and NRF 9.3 score (P = 0.02), but not other diet quality indicators, were associated with lower body mass index percentile in adjusted analyses.

CONCLUSIONS

Data demonstrate poor diet quality in youth with type 1 diabetes and provide support for the importance of diet quality for weight management. Future research on determinants of dietary intake and methods to promote improved diet quality would be useful to inform clinical care.

Glycemic index and glycemic load are associated with some cardiovascular risk factors among the PREMIER study participants

BACKGROUND

The clinical significance of glycemic index (GI) and glycemic load (GL) is inconclusive.

OBJECTIVE

This study was conducted to examine the association of GI and GL with clinical cardiovascular disease (CVD) risk factors including body weight, blood pressure (BP), serum lipids, fasting glucose, insulin and homocysteine over time among the PREMIER participants.

DESIGN

PREMIER was an 18-month randomized lifestyle intervention trial, conducted from 2000 to 2002, designed to help participants reduce BP by following the Dietary Approaches to Stop Hypertension (DASH) dietary pattern, losing weight, reducing sodium and increasing physical activity. GI and GL were estimated from 24 h diet recall data at baseline, 6 and 18 months after intervention. PROC MIXED model was used to examine the association of changes in GI or GL with changes in CVD risk factors.

RESULTS

A total of 756 randomized participants, 62% females and 34% African Americans and who averaged 50.0±0.3 years old and 95.3±0.7 kg, were included in this report. Neither GI nor GL changes was associated with changes in any risk factors at 6 months. At 18 months, however, the GI change was significantly and positively associated with total cholesterol (TC) change only (p<0.05, β=23.80±12.11 mg/dL or 0.62±0.31 mmol/L) with a significant age interaction. The GL change was significantly associated with TC (p=0.02, β=0.28±0.15 mg/dL or 0.01±0.00 mmol/L) positively and with low density lipoprotein cholesterol (LDL-C) changes negatively (p=0.03, β=-0.01±0.00 mg/dL or -0.00±0.00 mmol/L), and significant age interactions were observed for both.

CONCLUSIONS

GI and GL was associated with TC and LDL-C after controlling for energy, fat and fiber intake and other potential confounders and the associations were modified by age. Further investigation into this relationship is important because of its potential clinical impact.

Continuous glucose monitoring: a review for behavioral researchers

OBJECTIVE

Continuous glucose monitoring (CGM) systems collect and store glucose data in an ongoing fashion for several days at a time. The main advantage of CGM is that it can help identify fluctuations and trends that would otherwise go unnoticed with other glucose measures. Here, we provide a review of CGM for behavioral researchers.

METHODS

We begin with a brief review of diabetes and glucose measurement and then describe what CGM is and reference the commercial CGM systems currently available. We discuss the challenges involved in using CGM in behavioral research. We then present a broad overview of CGM in behavioral research, including data from ours and others' research programs. Finally, we cover some practical issues to be considered when using CGM, suggest reporting guidelines for the behavioral researcher, and offer suggestions for future research.

RESULTS

Only a handful of behavioral researchers are using CGM, although its use is increasing. The main ways that CGM is being used in behavioral research is to investigate basic biobehavioral processes, to assess the effects of behavioral interventions on diabetes control, and to use CGM itself as a behavior modification and teaching tool in diabetes self-management interventions.

CONCLUSIONS

Continuous glucose monitoring holds promise to help behavioral researchers unravel the complex relationships among glucose and intrapersonal, interpersonal, and contextual factors. However, the uptake of CGM for this purpose is limited, and the possibilities for its use are largely unmet. We encourage behavioral researchers to implement CGM in their protocols and to do so in a way that maximizes its explanatory power.

Glycemic index predicts individual glucose responses after self-selected breakfasts in free-living, abdominally obese adults

The degree to which an individual's glycemic response to a meal is determined by the glycemic index (GI) and other components of the meal remains unclear, especially when meals are not consumed in a highly controlled research setting. To address this question, we analyzed data collected during the run-in period of a clinical trial. Free-living, nondiabetic adults (n = 57) aged 53.9 ± 9.8 y (mean ± SD) with a BMI of 33.9 ± 5.3 kg/m(2) and waist circumference of 109 ± 11 cm underwent a 75-g oral glucose tolerance test (OGTT) and, on a separate day, wore a continuous glucose-monitoring system (CGMS) for 24 h during which time they recorded all foods consumed. The protein, fat, and available carbohydrate (avCHO) content and GI of the breakfast meals were calculated from the food records and the incremental areas under the glycemic response curves (iAUC) for 2 h after breakfast (iAUC(breakfast)) were calculated from CGMS data. Values for iAUC(breakfast), avCHO, fat, fiber, and BMI were normalized by log-transformation. The ability of participant characteristics and breakfast composition to predict individual iAUC(breakfast) responses was determined using step-wise multiple linear regression. A total of 56% of the variation in iAUC(breakfast) was explained by GI (30%; P < 0.001), iAUC after the OGTT (11%; P < 0.001), avCHO (11%; P < 0.001), and waist circumference (3%; P = 0.049); the effects of fat, protein, dietary fiber, age, sex, and BMI were not significant. We concluded that, in free-living, abdominally obese adults, GI is a significant determinant of individual glycemic responses elicited by self-selected breakfast meals. In this study, GI was a more important determinant of glycemic response than carbohydrate intake.

Improving the estimation of mealtime insulin dose in adults with type 1 diabetes: the Normal Insulin Demand for Dose Adjustment (NIDDA) study

OBJECTIVE

Although carbohydrate counting is routine practice in type 1 diabetes, hyperglycemic episodes are common. A food insulin index (FII) has been developed and validated for predicting the normal insulin demand generated by mixed meals in healthy adults. We sought to compare a novel algorithm on the basis of the FII for estimating mealtime insulin dose with carbohydrate counting in adults with type 1 diabetes.

RESEARCH DESIGN AND METHODS

A total of 28 patients using insulin pump therapy consumed two different breakfast meals of equal energy, glycemic index, fiber, and calculated insulin demand (both FII = 60) but approximately twofold difference in carbohydrate content, in random order on three consecutive mornings. On one occasion, a carbohydrate-counting algorithm was applied to meal A (75 g carbohydrate) for determining bolus insulin dose. On the other two occasions, carbohydrate counting (about half the insulin dose as meal A) and the FII algorithm (same dose as meal A) were applied to meal B (41 g carbohydrate). A real-time continuous glucose monitor was used to assess 3-h postprandial glycemia.

RESULTS

Compared with carbohydrate counting, the FII algorithm significantly decreased glucose incremental area under the curve over 3 h (-52%, P = 0.013) and peak glucose excursion (-41%, P = 0.01) and improved the percentage of time within the normal blood glucose range (4-10 mmol/L) (31%, P = 0.001). There was no significant difference in the occurrence of hypoglycemia.

CONCLUSIONS

An insulin algorithm based on physiological insulin demand evoked by foods in healthy subjects may be a useful tool for estimating mealtime insulin dose in patients with type 1 diabetes.

Isomaltulose Improves Postexercise Glycemia by Reducing CHO Oxidation in T1DM

PURPOSE

individuals with type 1 diabetes mellitus (T1DM) are encouraged to consume CHO to prevent hypoglycemia during or after exercise. However, the research comparing specific types of CHO is limited. This study compared the alterations in metabolism and fuel oxidation in response to running after preexercise ingestion of isomaltulose or dextrose in T1DM.

METHODS

after preliminary testing, on two occasions, eight T1DM individuals consumed 75 g of either dextrose (DEX; GI = 96) or isomaltulose (ISO; GI = 32), 2 h before performing 45 min of treadmill running at 80% ± 1% VO(2peak). Blood glucose (BG) was measured for 2 h before and 3 h after exercise. Cardiorespiratory parameters were collected at rest and during exercise. Data (mean ± SEM) were analyzed using repeated-measures ANOVA.

RESULTS

there was a smaller increase in BG in the preexercise period under ISO with peak BG occurring at 120 min after ingestion compared with 90 min under DEX (Δ+4.5 ± 0.4 vs Δ+9.1 ± 0.6 mmol·L, P < 0.01). During the final 10 min of exercise, there were lower CHO (ISO 2.85 ± 0.07 vs DEX 3.18 ± 0.08 g·min, P < 0.05) and greater lipid oxidation rates (ISO 0.33 ± 0.03 vs DEX 0.20 ± 0.03 g·min, P < 0.05) under ISO. After exercise, ISO BG was lower than DEX for the entire 180-min period, with BG area under the curve and mean BG concentrations being 21% ± 3% and 3.0 ± 0.4 mmol·L lower, respectively (P < 0.05).

CONCLUSIONS

consumption of ISO improves BG responses during and after exercise through reduced CHO and improved lipid oxidation during the later stages of exercise.

Effects of meals with different glycaemic index on postprandial blood glucose response in patients with Type 1 diabetes treated with continuous subcutaneous insulin infusion

OBJECTIVE

To evaluate the impact of high-glycaemic index and low-glycaemic index meals on postprandial blood glucose in patients with Type 1 diabetes treated with continuous subcutaneous insulin infusion.

METHODS

Sixteen patients with Type 1 diabetes under continuous subcutaneous insulin infusion treatment, age 36±0.5 years (mean±sem), HbA(1c) 7.6±0.2% (56±1.1 mmol/mol), consumed two test meals with an identical macronutrient composition, but with a different glycaemic index: 59 vs. 90. Blood glucose was checked before the test meal and every 30 min thereafter for 180 min. The same preprandial insulin dose was administered on the two occasions.

RESULTS

Blood glucose concentrations following the low-glycaemic index meal were significantly lower than those of the high-glycaemic index meal (P<0.05 to P<0.01). The blood glucose area under the curve after the low-glycaemic index meal was 20% lower than after the high-glycaemic meal (P=0.006).

CONCLUSIONS

  Our data show that meals with the same carbohydrate content but a different glycaemic index produce clinically significant differences in postprandial blood glucose.

The evidence for medical nutrition therapy for type 1 and type 2 diabetes in adults

This article reviews the evidence and nutrition practice recommendations from the American Dietetic Association's nutrition practice guidelines for type 1 and type 2 diabetes in adults. The research literature was reviewed to answer nutrition practice questions and resulted in 29 recommendations. Here, we present the recommendations and provide a comprehensive and systematic review of the evidence associated with their development. Major nutrition therapy factors reviewed are carbohydrate (intake, sucrose, non-nutritive sweeteners, glycemic index, and fiber), protein intake, cardiovascular disease, and weight management. Contributing factors to nutrition therapy reviewed are physical activity and glucose monitoring. Based on individualized nutrition therapy client/patient goals and lifestyle changes the client/patient is willing and able to make, registered dietitians can select appropriate interventions based on key recommendations that include consistency in day-to-day carbohydrate intake, adjusting insulin doses to match carbohydrate intake, substitution of sucrose-containing foods, usual protein intake, cardioprotective nutrition interventions, weight management strategies, regular physical activity, and use of self-monitored blood glucose data. The evidence is strong that medical nutrition therapy provided by registered dietitians is an effective and essential therapy in the management of diabetes.

A prospective clinical pilot-trial comparing the effect of an optimized mixed diet versus a flexible low-glycemic index diet on nutrient intake and HbA(1c) levels in children with type 1 diabetes

BACKGROUND

Low-glycemic index (GI) diet vs. high-GI diet improves glycemic control, but it is not clear whether a low-GI diet is superior to an optimized mixed diet (OMD).

METHODS

This was a 12-week parallel-group pilot-trial including 17 children with type 1 diabetes. A separate dietary education into the allocated diet (OMD vs. low-GI) was performed. Nutrition was recorded by means of a three-day dietary record.

OBJECTIVES

The primary objective was to determine the macro- and micronutrient composition of the different diets, the secondary objective was to determine the short-term effect on HbA(1c) levels.

RESULTS

In the low-GI group carbohydrate intake decreased, fat intake increased by trend. In the OMD group fat and energy intake decreased. No changes of HbA(1c) levels between the groups were observed.

CONCLUSION

OMD could have positive effects in overweight and obese diabetic children, since a reduction in fat and energy intake can be achieved. The findings of this pilot-trial suggest that OMD could be superior to a low-GI diet.