Kirstine J Bell1, Alan W Barclay2, Peter Petocz3, Stephen Colagiuri1, Jennie C Brand-Miller4. 1. Boden Institute of Obesity, Nutrition, Exercise and Eating Disorders, and the School of Molecular Bioscience, University of Sydney, Sydney, NSW, Australia. 2. Boden Institute of Obesity, Nutrition, Exercise and Eating Disorders, and the School of Molecular Bioscience, University of Sydney, Sydney, NSW, Australia; Australian Diabetes Council, Sydney, NSW, Australia. 3. Department of Statistics, Macquarie University, Sydney, NSW, Australia. 4. Boden Institute of Obesity, Nutrition, Exercise and Eating Disorders, and the School of Molecular Bioscience, University of Sydney, Sydney, NSW, Australia. Electronic address: jennie.brandmiller@sydney.edu.au.
Abstract
BACKGROUND: Although carbohydrate counting is the recommended dietary strategy for achieving glycaemic control in people with type 1 diabetes, the advice is based on narrative review and grading of the available evidence. We aimed to assess by systematic review and meta-analysis the efficacy of carbohydrate counting on glycaemic control in adults and children with type 1 diabetes. METHODS: We 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. 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. FINDINGS: We identified seven eligible trials, of 311 potentially relevant studies, comprising 599 adults and 104 children with type 1 diabetes. 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], 95% CI -0·75 to 0·06; p=0·096). We 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 (95% CI -0·91 to -0·37; p<0·0001). INTERPRETATION: There is some evidence to support the recommendation of carbohydrate counting over alternate advice or usual care in adults with type 1 diabetes. Additional studies are needed to support promotion of carbohydrate counting over other methods of matching insulin dose to food intake. FUNDING: None.
BACKGROUND: Although carbohydrate counting is the recommended dietary strategy for achieving glycaemic control in people with type 1 diabetes, the advice is based on narrative review and grading of the available evidence. We aimed to assess by systematic review and meta-analysis the efficacy of carbohydrate counting on glycaemic control in adults and children with type 1 diabetes. METHODS: We 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. 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. FINDINGS: We identified seven eligible trials, of 311 potentially relevant studies, comprising 599 adults and 104 children with type 1 diabetes. 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], 95% CI -0·75 to 0·06; p=0·096). We 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 (95% CI -0·91 to -0·37; p<0·0001). INTERPRETATION: There is some evidence to support the recommendation of carbohydrate counting over alternate advice or usual care in adults with type 1 diabetes. Additional studies are needed to support promotion of carbohydrate counting over other methods of matching insulin dose to food intake. FUNDING: None.
Authors: Derek LeRoith; Geert Jan Biessels; Susan S Braithwaite; Felipe F Casanueva; Boris Draznin; Jeffrey B Halter; Irl B Hirsch; Marie E McDonnell; Mark E Molitch; M Hassan Murad; Alan J Sinclair Journal: J Clin Endocrinol Metab Date: 2019-05-01 Impact factor: 5.958