Effectiveness and safety of carbohydrate counting in the management of adult patients with type 1 diabetes mellitus: a systematic review and meta-analysis

Unmet needs in the treatment of type 1 diabetes: why is it so difficult to achieve an improvement in metabolic control?

The development of advanced diabetes technology has permitted persons with type 1 diabetes mellitus to improve metabolic control significantly, particularly with the development of advanced hybrid closed-loop systems which have improved the quality of life by reducing hypoglycemia, decreasing macroangiopathy and microangiopathy-related complications, ameliorating HbA1c and improving glycemic variability. Despite the progression made over the past few decades, there is still significant margin for improvement to be made in terms of attaining appropriate metabolic control. Various factors are responsible for poor glycemic control including inappropriate carbohydrate counting, repeated bouts of hypoglycemia, hypoglycemia unawareness, cutaneous manifestations due to localized insulin use and prolonged use of diabetes technology, psychosocial comorbidities such as eating disorders or 'diabulimia', the coexistence of insulin resistance among people with type 1 diabetes and the inability to mirror physiological endogenous pancreatic insulin secretion appropriately. Hence, the aim of this review is to highlight and overcome the barriers in attaining appropriate metabolic control among people with type 1 diabetes by driving research into adjunctive treatment for coexistent insulin resistance and developing new advanced diabetic technologies to preserve β cell function and mirror as much as possible endogenous pancreatic functions.

Effects of basic carbohydrate counting versus standard dietary care for glycaemic control in type 2 diabetes (The BCC Study): a randomised, controlled trial

BACKGROUND

Clinical guidelines recommend basic carbohydrate counting (BCC), or similar methods to improve carbohydrate estimation skills and to strive for higher consistency in carbohydrate intake potentially improving glycaemic control. However, evidence for this approach in type 2 diabetes (T2D) is limited.

OBJECTIVE

To examine the efficacy of a structured education program in BCC as add-on to standard dietary care on glycaemic control in individuals with T2D.

METHODS

The BCC Study was a randomized, controlled, open-label, parallel-group trial. Individuals with T2D aged 18-75 years with glycated haemoglobin A1c (HbA1c) 53-97 mmol/mol (7.0-11.0%) were randomly assigned (1:1) to BCC or standard dietary care. The primary outcomes were differences in changes in HbA1c or glycaemic variability (calculated as mean amplitude of glycaemic excursions [MAGE]) between groups after six months of intervention.

RESULTS

Between September 2018 and July 2021, 48 participants were randomly assigned, 23 to BCC and 25 to standard dietary care. Seven participants did not receive the allocated intervention. From a baseline-adjusted mean of 65 mmol/mol (95% CI 62-68 [8.1%, 7.8-8.4]), HbA1c changed by -5 mmol/mol (-8 to -1 [-0.5%, -0.7 to -0.1]) in BCC and -3 mmol/mol (-7 to 1 [-0.3%, -0.6 to 0.1]) in standard care with an estimated treatment effect of -2 mmol/mol (-7 to 4 [-0.2%, -0.6 to 0.4]); p = 0.554. From a baseline-adjusted mean of 4.2 mmol/l (3.7 to 4.8), MAGE changed by -16% (-33 to 5) in BCC and by -3% (-21 to 20) in standard care with an estimated treatment effect of -14% (-36 to 16); p = 0.319. Only median carbohydrate estimation error in favour of BCC (estimated treatment difference -55% (-70 to -32); p < 0.001) remained significant after multiple testing adjustment.

CONCLUSIONS

No glycaemic effects were found but incorporating BCC as a supplementary component to standard dietary care led to improved skills in estimating carbohydrate intake among individuals with T2D.

The effect of carbohydrate intake on glycaemic control in individuals with type 1 diabetes: a randomised, open-label, crossover trial

Background

Few studies have examined the effects of lower carbohydrate diets on glucose control in persons with type 1 diabetes (T1D). The objective of the study was to investigate whether a moderate carbohydrate diet improves glucose control in persons with T1D.

Methods

A randomised, multicentre, open-label, crossover trial over 12 weeks. There were 69 individuals assessed for eligibility, 54 adults with T1D and HbA1c ≥ 58 mmol/mol (7.5%) were randomised. Interventions were moderate carbohydrate diet versus traditional diet (30 vs 50% of total energy from carbohydrates) over four weeks, with a four-week wash-out period between treatments. Masked continuous glucose monitoring was used to evaluate effects on glucose control. The primary endpoint was the difference in mean glucose levels between the last 14 days of each diet phase.

Findings

50 individuals were included in the full analysis set with a mean baseline HbA1c of 69 mmol/mol (8.4%), BMI 29 kg/m2, age of 48 years, and 50% were female. The difference in mean glucose levels between moderate carbohydrate and traditional diet was -0.6 mmol/L, 95% CI -0.9 to -0.3, p < 0.001. Time in range increased during moderate carbohydrate diet by 4.7% (68 min/24 h) (95% CI 1.3 to 8.0), p = 0.008. Time above range (>10 mmol/L) decreased by 5.9% (85 min/24 h), 95% CI -9.6 to -2.2, p = 0.003. There were no significant differences in the standard deviation of glucose levels (95% CI -0.3 to 0.0 mmol/L, p = 0.15) or hypoglycaemia in the range <3.9 mmol/L (95% CI -0.4 to 2.9%, p = 0.13) and <3.0 mmol/L (95% CI -0.4 to 1.6%, p = 0.26). Four participants withdrew, none because of adverse events. There were no serious adverse events including severe hypoglycaemia and ketoacidosis. Mean ketone levels were 0.17 (SD 0.14) mmol/L during traditional and 0.18 (SD 0.13) mmol/L during moderate carbohydrate diet (p = 0.02).

Interpretation

A moderate carbohydrate diet is associated with decreases in mean glucose levels and time above range and increases in time in range without increased risk of hypoglycaemia or ketoacidosis compared with a traditional diet in individuals with T1D.

Funding

The Healthcare Board, Region Västra Götaland, The Dr P Håkansson Foundation and the Swedish state under the agreement between the Swedish government and the county councils, the ALF-agreement [ALFGBG-966173].

Associations Between Psychosocial Needs, Carbohydrate-Counting Behavior, and App Satisfaction: A Randomized Crossover App Trial on 92 Adults With Diabetes

To examine whether psychosocial needs in diabetes care are associated with carbohydrate counting and if carbohydrate counting is associated with satisfaction with diabetes applications' usability, a randomized crossover trial of 92 adults with type 1 or 2 diabetes requiring insulin therapy tested two top-rated diabetes applications, mySugr and OnTrack Diabetes. Survey responses on demographics, psychosocial needs (perceived competence, autonomy, and connectivity), carbohydrate-counting frequency, and application satisfaction were modeled using mixed-effect linear regressions to test associations. Participants ranged between 19 and 74 years old (mean, 54 years) and predominantly had type 2 diabetes (70%). Among the three tested domains of psychosocial needs, only competence-not autonomy or connectivity-was found to be associated with carbohydrate-counting frequency. No association between carbohydrate-counting behavior and application satisfaction was found. In conclusion, perceived competence in diabetes care is an important factor in carbohydrate counting; clinicians may improve adherence to carbohydrate counting with strategies designed to improve perceived competence. Carbohydrate-counting behavior is complex; its impact on patient satisfaction of diabetes application usability is multifactorial and warrants consideration of patient demographics such as sex as well as application features for automated carbohydrate counting.

Healthy lifestyle and genomic ancestry related to good glycemic control in type 1 diabetes patients from Northeastern Brazil: a hierarchical analysis

Introduction

This study aimed to investigate the sociodemographic factors, dietary adherence, regular physical activity, and genomic ancestry percentage associated with good glycemic control in Brazilian patients with type 1 diabetes (T1D) using a hierarchical approach.

Methods

A cross-sectional study was conducted in 152 T1D patients. Glycated hemoglobin (HbA1C) levels were measured to evaluate the glycemic control status (good, moderate, or poor). Independent factors included sex, age, self-reported skin color, educational level, family income, dietary patterns, and physical activity. The percentage of genomic ancestry (Native American, European, and African) was influenced by a panel of 46 autosomal insertion/deletion ancestry markers. Statistical analyses included receiver operating characteristic curves, and hierarchical logistic regression analysis.

Results

The hierarchical analysis, patients who had high dietary adherence showed a positive association with good glycemic control (adjustedOR = 2.56, 95% CI:1.18-5.59, P = 0.016). Thus, age greater than 40 years was associated with good glycemic control compared to the children and adolescents group (adjustedOR = 4.55, 95% CI:1.14-18.1, P = 0.031). Males were associated with good glycemic control (adjustedOR = 2.00, 95% CI:1.01-4.00, P =0.047).

Conclusion

The study findings suggest that consistent adherence to dietary regimens is associated with good glycemic control after adjusting for sociodemographic and genomic ancestry factors in an admixed population of T1D patients from Northeast Brazil.

Characteristics of carbohydrate counting practice associated with adequacy of glycated hemoglobin in adults with type 1 diabetes mellitus in Brazil

Background

The Carbohydrate Counting (CC) is directly associated with achieving glycemic control by people with Type 1 Diabetes Mellitus (T1DM). Therefore, this study aims to analyze characteristics of the CC practice associated with the adequacy of glycated hemoglobin (HbA1c) in adults with T1DM in Brazil.

Methods

The study was cross-sectional, carried out using an online form with questions about knowledge of CC, clinical, anthropometric, sociodemographic data, follow-up with health professionals and understanding of the concepts of CC. Pearson's chi-square test and binomial logistic regression analysis (p<0.05) were applied.

Results

173 adults participated, of which 57.2% had increased HbA1c (≥7%). Having the diabetes duration <10 years (p=0.006), performing the CC at lunch (p=0.040) and dinner (p=0.018), using specific applications to perform the CC (p=0.001), having learned to perform CC with a nutritionist (p=0.037) and knowing how to correctly define the concepts of food bolus (p=0.001), correction bolus (p<0.001) and insulin/carbohydrate ratio (p<0.001) was associated with having adequate HbA1c (<7%). Participants who were undergoing CC practice were 3.273 times more likely to have adequate HbA1c and participants with diabetes duration <10 years were 2.686 times more likely to have adequate HbA1c.

Conclusion

It was concluded that variables transversal to CC favor adequate HbA1c values in adults with T1DM and that practicing CC and having a diabetes duration of less than 10 years are predictive factors of having adequate HbA1c.

Evidence-based European recommendations for the dietary management of diabetes

Diabetes management relies on effective evidence-based advice that informs and empowers individuals to manage their health. Alongside other cornerstones of diabetes management, dietary advice has the potential to improve glycaemic levels, reduce risk of diabetes complications and improve health-related quality of life. We have updated the 2004 recommendations for the nutritional management of diabetes to provide health professionals with evidence-based guidelines to inform discussions with patients on diabetes management, including type 2 diabetes prevention and remission. To provide this update we commissioned new systematic reviews and meta-analyses on key topics, and drew on the broader evidence available. We have strengthened and expanded on the previous recommendations to include advice relating to dietary patterns, environmental sustainability, food processing, patient support and remission of type 2 diabetes. We have used the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach to determine the certainty of evidence for each recommendation based on findings from the commissioned and identified systematic reviews. Our findings indicate that a range of foods and dietary patterns are suitable for diabetes management, with key recommendations for people with diabetes being largely similar for those for the general population. Important messages are to consume minimally processed plant foods, such as whole grains, vegetables, whole fruit, legumes, nuts, seeds and non-hydrogenated non-tropical vegetable oils, while minimising the consumption of red and processed meats, sodium, sugar-sweetened beverages and refined grains. The updated recommendations reflect the current evidence base and, if adhered to, will improve patient outcomes.

Adult-onset autoimmune diabetes

Adult-onset autoimmune (AOA) diabetes pathophysiology starts with immune changes, followed by dysglycaemia and overt disease. AOA diabetes can occur as classic type 1 diabetes when associated with severe loss of insulin secretion. More frequently, it is diagnosed as latent autoimmune diabetes in adults, a slowly progressing form with late onset, a long period not requiring insulin, and it is often misdiagnosed as type 2 diabetes. As its clinical presentation varies remarkably and immune markers often lack specificity, it is challenging to classify each case ad hoc, especially when insulin treatment is not required at diagnosis. Proper care of AOA diabetes aims to prevent complications and to improve quality of life and life expectancy. To achieve these goals, attention should be paid to lifestyle factors, with the aid of pharmacological therapies properly tailored to each individual clinical setting. Given the heterogeneity of the disease, choosing the right therapy for AOA diabetes is challenging. Most of the trials testing disease-modifying therapies for autoimmune diabetes are conducted in people with childhood onset, whereas non-insulin diabetes therapies have mostly been studied in the larger population with type 2 diabetes. More randomized controlled trials of therapeutic agents in AOA diabetes are needed.

Adherence to Mediterranean Diet Is Associated With Better Glycemic Control in Children With Type 1 Diabetes: A Cross-Sectional Study

Type 1 diabetes (T1D) is a chronic condition, with increased morbidity and mortality, due to a higher rate of cardiovascular disease among other factors. Cardiovascular risk increases with the worse glycemic profile. Nutrition has a deep impact on diabetes control. Adherence to the Mediterranean diet (MD) has been shown to decrease cardiovascular risk in children and adults with obesity and adults with type 2 diabetes, but its impact on T1D children has been scarcely analyzed. We hypothesized that the degree of adherence to MD could relate to the increased time in range in children with T1D.

Patients and Methods

Cross-sectional analysis involving two university hospitals. We measured the adherence to MD with the Mediterranean Diet Quality Index for children and teenagers (KIDMED) questionnaire, which is a validated tool for this purpose. A score of &lt;5 indicates poor adherence to MD, while a good adherence is indicated by a score of &gt;7. Demographic and clinical data were registered on the same day that the questionnaire was taken, with informed consent. Additionally, the patients' ambulatory glucose profiles (AGPs), were registered from the participants' glucose monitors (continuous or flash devices), and daily insulin needs were recorded from patients' insulin pumps (n=28). Other cardiovascular risk factors such as lipid profile, vitamin D levels, and other biochemical parameters were registered from a blood test, performed 2 weeks before recruitment, as part of the patients' annual screening.

Results

Ninety-seven patients (44 girls), with an average age of 11.4 years (± 3.01), were included. Seventy-one of them were on multiple daily injection regimens, and all had either continuous or flash glucose monitoring. Fifty-three had HbA1c levels of &lt;7.5%, while only 21 had a time in range (TIR) of &gt;70%. Contingency analysis showed that the odds of having HbA1c &lt;7.5% increase in children with KIDMED score of &gt;7 (O.R. 2.38; ICR 1.05–5.41; p = 0.036). Moreover, the KIDMED score and the HbA1c levels were negatively correlated (R: −0.245; p-value: 0.001), while the KIDMED score and TIR showed a positive correlation (R: 0.200; p-value: 0.009).

Conclusions

Our data suggest that adherence to MD may contribute to better glycemic control in children. This should be taken into account at the time of nutritional education on T1D patients and their families.

Association Between a Low Carbohydrate Diet, Quality of Life, and Glycemic Control in Australian Adults Living With Type 1 Diabetes: Protocol for a Mixed Methods Pilot Study

BACKGROUND

Globally, the prevalence of type 1 diabetes mellitus (T1DM) is rising. In 2020, a total of 124,652 Australians had T1DM. Maintaining optimal glycemic control (hemoglobin A_1c ≤7.0%, ≤53 mmol/mol) on a standard carbohydrate diet can be a challenge for people living with T1DM. The Diabetes Complications and Control Trial established that macrovascular and microvascular complications could be reduced by improving glycemic control. Recent studies have found that a very low or low carbohydrate diet can improve glycemic control. However, the overall evidence relating to an association between a very low or low carbohydrate diet and glycemic control in people living with T1DM is both limited and mixed. In addition, research has suggested that a reduced quality of life due to anxiety and depression adversely influences glycemic control. Despite a potential link between a very low or low carbohydrate diet and optimal glycemic control, to our knowledge, no research has examined an association between a low carbohydrate diet, quality of life, and glycemic control, making this study unique in its approach.

OBJECTIVE

The study aims to develop a validated diabetes-specific quality of life questionnaire for use in Australian adults with T1DM and to determine if an association exists between a low carbohydrate diet, quality of life, and glycemic control in Australian adults living with T1DM.

METHODS

This cross-sectional study will be conducted in a tertiary hospital outpatient setting and will consist of 3 phases: phase 1, online Australian diabetes-specific quality of life questionnaire development and piloting (25-30 adults with T1DM); phase 2, questionnaire validation (364 adults with T1DM); and phase 3, a 12-week dietary intervention to determine if an association exists between a low carbohydrate diet, quality of life, and glycemic control in adults with T1DM (16-23 adults with T1DM). The validation of the study-developed Australian diabetes-specific quality of life questionnaire, and changes in hemoglobin A_1c and quality of life in adults with T1DM while undertaking a low carbohydrate diet over 12 weeks will be the primary outcomes of this study.

RESULTS

Phase 1 of the study is currently open for recruitment and has recruited 12 participants to date. It is anticipated that the first results will be submitted for publication in November 2021. Presently, no results are available.

CONCLUSIONS

This study is the first of its kind in that it will be the first to generate a new validated instrument, which could be used in evidence-based practice and research to understand the quality of life of Australian adults with T1DM. Second, the low carbohydrate dietary intervention outcomes could be used to inform clinicians about an alternative approach to assist T1DM adults in improving their quality of life and glycemic control. Finally, this study could warrant the development of an evidence-based low carbohydrate dietary guideline for adults living with T1DM with the potential to have a profound impact on this population.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04213300; https://clinicaltrials.gov/ct2/show/NCT04213300.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/25085.

Effects of nutrition education using a food-based approach, carbohydrate counting or routine care in type 1 diabetes: 12 months prospective randomized trial

INTRODUCTION

Evidence on the effects of structured nutrition education is weak in adults with type 1 diabetes mellitus (T1D) with moderately impaired glycemic control. Objective was to compare the effects of different types of nutrition education programs on glycemic control, cardiovascular risk factors, quality of life, diet quality and food choices in T1D.

RESEARCH DESIGN AND METHODS

A 12 months randomized controlled study conducted at nine diabetes specialist centers with three parallel arms: (i) a food-based approach (FBA) including foods with low glycemic index or (ii) carbohydrate counting (CC) according to today's standard practice or (iii) individual sessions according to routine care (RC). The primary end point was difference in glycated hemoglobin A1c (HbA1c) between groups at 12 months.

RESULTS

159 patients were randomized (FBA: 51; CC: 52; RC: 55). Mean (SD) age 48.6 (12.0) years, 57.9% females and mean (SD) HbA1c level 63.9 (7.9) mmol/mol, 8% (0.7%). After 3 months, HbA1c improved in both FBA and CC compared with RC. However, there were no significant differences at 12 months in HbA1c; FBA versus RC (-0.4 mmol/mol (1.3), 0.04% (0.1%)), CC versus RC (-0.8 mmol/mol (1.2), 0.1% (0.1%)), FBA versus CC (0.4 mmol/mol (0.3), 0.04% (0.01%)). At 12 months, intake of legumes, nuts and vegetables was improved in FBA versus CC and RC. FBA also reported higher intake of monounsaturated and polyunsaturated fats compared with RC, and dietary fiber, monounsaturated and polyunsaturated fats compared with CC (all p values <0.05). There were no differences in blood pressure levels, lipids, body weight or quality of life.

CONCLUSIONS

Nutrition education using an FBA, CC or RC is equivalent in terms of HbA1c and cardiovascular risk factors in persons with T1D with moderately impaired glycemic control. An FBA had benefits regarding food choices compared with CC and RC.

The Mediterranean Diet is Associated with an Improved Quality of Life in Adults with Type 1 Diabetes

This study aimed to assess the potential association between dietary patterns (i.e., the Mediterranean Diet (MedDiet) and healthy eating) and patient-reported quality of life (QoL) and treatment satisfaction (TS) in adults with type 1 diabetes (T1D). A food frequency questionnaire, the Audit of Diabetes-Dependent Quality of Life (ADDQoL-19), and the Diabetes Treatment Satisfaction Questionnaire-status version (DTSQ-s) were administered via personal interviews to 258 participants with T1D. Multivariable analysis showed that a moderate or high adherence to the MedDiet was associated with greater diabetes-specific QoL (β = 0.32, 95% CI = 0.03; 0.61; p = 0.029). None of the dietary quality indexes (i.e., the alternate Mediterranean Diet Score (aMED) and the alternate Healthy Eating Index (aHEI)) were associated with the overall TS. However, the aHEI was positively associated with the specific items of TS “convenience” and “flexibility” (β = 0.03, 95% CI = 0.00; 0.06; p = 0.042 and β = 0.04; 95% CI = 0.01; 0.06; p = 0.011, respectively). On the other hand, the aHEI was negatively associated with the dimension “recommend to others” (β = −0.5, 95% CI = −0.99; −0.02; p = 0.042). In conclusion, a moderate and high adherence to the MedDiet was associated with greater QoL. Although neither aMED nor aHEI were associated with the overall TS, some specific items were positively (i.e., “convenience”, “flexibility”) or negatively (“recommend to others”) related to the aHEI. Further research is needed to assess how to improve medical nutrition therapy and its impact on patient-reported outcomes in people with T1D.

Efficacy and Safety of Fast-Acting Insulin Aspart in People with Type 1 Diabetes Using Carbohydrate Counting: A Post Hoc Analysis of Two Randomised Controlled Trials

INTRODUCTION

Insulin dosing based on carbohydrate counting is the gold standard for improving glycaemic control in type 1 diabetes (T1D). This post hoc analysis aimed to explore the efficacy and safety of fast-acting insulin aspart (faster aspart) according to bolus dose adjustment method in people with T1D.

METHODS

Post hoc analysis of two 26-week, treat-to-target, randomised trials investigating treatment with double-blind mealtime faster aspart, insulin aspart (IAsp), or open-label post-meal faster aspart (onset 1, n = 1143; onset 8, n = 1025). Participants with previous experience continued carbohydrate counting (onset 1, n = 669 [58.5%]; onset 8, n = 428 [41.8%]), while remaining participants used a bolus algorithm.

RESULTS

In onset 1, HbA1c reduction was statistically significantly in favour of mealtime faster aspart versus IAsp with carbohydrate counting (estimated treatment difference [ETD 95% CI] - 0.19% [- 0.30; - 0.09]; - 2.08 mmol/mol [- 3.23; - 0.93]). In onset 8, there was no statistically significant difference in HbA1c reduction with either dose adjustment method, although a trend towards improved HbA1c was observed for mealtime faster aspart with carbohydrate counting (ETD - 0.14% [- 0.28; 0.003]; - 1.53 mmol/mol [- 3.10; 0.04]). In both trials, bolus insulin doses and overall rates of severe or blood glucose-confirmed hypoglycaemia were similar between treatments across dose adjustment methods.

CONCLUSION

For people with T1D using carbohydrate counting, mealtime faster aspart may offer improved glycaemic control versus IAsp, with similar insulin dose and weight gain and no increased risk of hypoglycaemia.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT01831765 (onset 1) and NCT02500706 (onset 8).

FUNDING

Novo Nordisk.

A Practical Guide to Delivering Nutritional Advice to People with Diabetes

Dietary advice is fundamental to the management of diabetes. Although ideally such advice should be delivered by a state-registered dietitian, it is more usually delivered by other health professionals. The primary focus for those with type 1 diabetes is carbohydrate counting and insulin adjustment and for the majority of people with type 2 diabetes, weight management is key. Patient-centred care is emphasised for the delivery of dietary advice. It is widely recognised that knowledge alone is not sufficient to induce behaviour change and practical approaches to a variety of behavioural interventions are discussed.