Although carbohydrate counting is the recommended dietary strategy for achieving glycaemic control in people with type 1 diabetes mellitus, the advice is based on narrative review and grading of the available evidence.
A study has assessed by systematic review and meta-analysis the efficacy of carbohydrate counting on glycaemic control in adults and children with type 1 diabetes mellitus.
Researchers screened and assessed randomised controlled trials of interventions longer than 3 months that compared carbohydrate counting with general or alternate dietary advice in adults and children with type 1 diabetes mellitus.
Change in glycated haemoglobin ( HbA1c ) concentration was the primary outcome.
The results of clinically and statistically homogenous studies were pooled and meta-analysed using the random-effects model to provide estimates of the efficacy of carbohydrate counting.
Researchers have identified seven eligible trials, of 311 potentially relevant studies, comprising 599 adults and 104 children with type 1 diabetes mellitus. Study quality score averaged 7.6 out of 13.
Overall there was no significant improvement in HbA1c concentration with carbohydrate counting versus the control or usual care ( -0.35% [ -3.9 mmol/mol ]; p=0.096 ).
Researchers have identified significant heterogeneity between studies, which was potentially related to differences in study design. In the five studies in adults with a parallel design, there was a 0.64% point ( 7.0 mmol/mol ) reduction in HbA1c with carbohydrate counting versus control ( p less than 0.0001 ).
There is some evidence to support the recommendation of carbohydrate counting over alternate advice or usual care in adults with type 1 diabetes mellitus.
Additional studies are needed to support promotion of carbohydrate counting over other methods of matching Insulin dose to food intake. ( Xagena )
Bell KJ et al, The Lancet Diabetes & Endocrinology 2014; 2: 133-140