Efficacy and safety of carbohydrate counting versus other forms of dietary advice in patients with type 1 diabetes mellitus: a systematic review and meta‐analysis of randomised clinical trials

Abstract

Background and aims Diabetes mellitus (DM) is one of the most prevalent chronic noncommunicable diseases globally, and the only way to reduce its complications is good glycaemic control. Insulin remains the only approved treatment for type 1 DM (T1DM) and is used by many with type 2 DM (T2DM). Carbohydrate counting is considered the ideal way to calculate meal‐related insulin doses as it allows greater flexibility in diet and could, in some people, reduce the burden of the disease. The primary objective of this systematic review was to assess carbohydrate counting efficacy in reducing glycated haemoglobin (HbA1c) levels and safety by not increasing hypoglycaemia risk, inducing an increase in body weight or blood lipids, or reducing the quality of life of people with T1DM. Methods We included randomised controlled clinical trials with a parallel‐group design comparing any carbohydrate counting forms with standard care or other forms of dietary advice or insulin dose calculation in people with T1DM with a follow up period of at least 3 months and with no restrictions in language, age or settings. As a primary outcome, we consider the change of HbA1c levels within at least 3 months. Secondary outcomes were hypoglycaemia events, body weight changes, blood lipids levels, and the total daily insulin dose. We also evaluated health‐related quality‐of‐life changes and questionnaires on satisfaction with treatment of diabetes. Results Data from 11 studies with 899 patients were retrieved with a mean follow‐up of 52 ± 35.5 weeks. Carbohydrate counting is not better in reducing HbA1clevels (SMD‐0.24%, 95% CI −0.68 to 0.21) than all dietary advice forms. However, this finding was highly heterogeneous. We identified three studies that account for most of the heterogeneity using clustering algorithms. A second analysis excluding these studies shows a meaningful reduction in HbA1c levels (SMD‐0.52%, 95% CI −0.82 to −0.23) with low heterogeneity. In the subgroup analysis, carbohydrate counting significantly reduces HbA1c levels compared with usual diabetes education. Carbohydrate counting does not relate to any substantial change in blood lipids, body weight, hypoglycaemia risk or daily insulin dose. Finally, we analysed the effect of trial duration on reduction in HbA1c levels and found no significant change related to time. Conclusions Carbohydrate counting is an efficacious technique to safely reduce the levels of HbA1c in adults and children compared with standard diabetes education, and its effect does not appear to change with prolonged time. Standardisation in reporting important outcomes such as hypoglycaemia and quality of life are vital to produce comparable evidence in carbohydrate counting clinical trials. This systematic review was registered in PROSPERO under code: CRD42020218499.

Evaluation of carbohydrate counting knowledge among individuals with type 1 diabetes mellitus in Saudi Arabia: a cross-sectional study

“… 8 A meta-analysis of randomised controlled trials showed evidence favouring the use of the CC method and a significant reduction in HbA1c levels compared with that of controls. 13 However, CC is a complex skill that is subject to error among children and young adults with T1DM and their families. 16 Therefore, identifying opportunities to develop CC skills can improve interventions and achieve accurate CC by patients and improved glycaemic management.…”

“…Previous studies have evaluated the efficacy and safety of the CC method in patients with T1DM 8 13–15. Scavone et al reported a significant reduction in glycated haemoglobin (HbA1c) levels, fewer hypoglycaemic events and decreased rapid insulin analogue doses after participants were taught about CC 8.…”

“…Scavone et al reported a significant reduction in glycated haemoglobin (HbA1c) levels, fewer hypoglycaemic events and decreased rapid insulin analogue doses after participants were taught about CC 8. A meta-analysis of randomised controlled trials showed evidence favouring the use of the CC method and a significant reduction in HbA1c levels compared with that of controls 13. However, CC is a complex skill that is subject to error among children and young adults with T1DM and their families 16.…”

Insulin-to-carbohydrate ratios

“…Since the focus is solely on carbohydrates and portions are not limited, patients may eat too many calories and overlook the amount and type of fats they consume 12. However, a recent systematic review and meta-analysis of randomized clinical trials indicated that carbohydrate counting does not relate to any substantial change in blood lipids or body weight 38. Nevertheless, weight change and lipid levels should be monitored and, when indicated, nutrition education and support provided to encourage eating patterns that align with the US Department of Agriculture's 2020-2025 Dietary Guidelines for Americans and the patient's weight goals 39…”

STUDIA: una aplicación para apoyar el conteo de carbohidratos simulando la dinámica de la glucosa

“…As well, carbohydrate counting was not associated with an increased risk of hypoglycemia, blood lipid concentration, or weight changes. Besides, it seems to improve quality of life, specifically in the disease or its treatment domains, and despite being an iterative educational technique, its effectiveness is not affected by its use for up to two years (18).…”