Brief ReportHepatic and intramyocellular glycogen stores in adults with type 1 diabetes and healthy controls
Introduction
Glycogen plays a major role in glucose homeostasis of healthy individuals as well as in patients with diabetes mellitus. Hepatic glycogen offers rapid provision of glucose to the systemic circulation and is of paramount importance for maintenance of euglycemia in individuals with type 1 diabetes (T1DM) which are at risk for hypoglycemia [1]. In addition, intramyocellular glycogen is an important local energy source of the working muscle [2].
In the literature, there is uncertainty whether glycogen metabolism and storage capacity differ between individuals with T1DM and healthy controls. While some reports suggest reduced glycogen synthesis in T1DM [3], [4], [5], others show comparable glycogen levels in T1DM and healthy individuals [6], [7], [8]. Such discrepancies may be partly due to differences in patient population, the degree of metabolic control, applied techniques, and the extent of standardization in the corresponding protocols.
The aim of the present study was to compare hepatic and intramyocellular glycogen stores in adult male individuals with and without T1DM matched for age, height, and weight. Measurements were performed after a standardization period using non-invasive 13C-magnetic resonance spectroscopy (MRS).
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Research design and methods
The study comprised 20 male individuals: 10 patients with C-peptide-negative, complication-free, and well-controlled T1DM and 10 healthy individuals. Groups were matched for age, weight, and height. Written informed consent was obtained. The protocol was approved by the local Ethics Committee, and the study was registered at ClinicalTrials.gov (NCT02068636).
A first visit included a detailed medical history, a physical exam, evaluation of the current insulin treatment, assessment of basal
Results
Characteristics of the participants are summarized in Table 1. Patients and controls had comparable age, weight, height, BMI, fat-free mass (FFM), and BMR. Mean ± SEM daily carbohydrate consumption was similar in the two groups with 350.6 ± 17.7 g in patients and 348 ± 13.1 g in controls, respectively (p = 0.922). All patients had non-detectable C-peptide levels, were under good glycemic control (mean HbA1c 55 ± 2.2 mmol/mol; 7.2 ± 0.2%) and had no evidence of diabetes-related complications. Diabetes duration
Discussion
The present study concomitantly examined hepatic and intramyocellular glycogen levels under standardized conditions in well-controlled adult individuals with T1DM and matched healthy controls. The main finding was that if measured under such conditions hepatic and intramyocellular glycogen levels were comparable between groups.
While previous studies have reported similar findings [6], [7], [8], they were essentially restricted to measurement of hepatic glycogen stores. The present study is the
Conflict of interest
The authors declare that there are no conflicts of interest with respect to the authorship or publication of this article.
Acknowledgements
The authors would like to thank the study participants. This study was funded by independent research grants by the Swiss National Science Foundation (#320030_149321/1 to CS and #310030-149779 to CB), and by the Ruth & Arthur Scherbarth Foundation, Bern (to LB).
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Post-exercise recovery for the endurance athlete with type 1 diabetes: a consensus statement
2021, The Lancet Diabetes and EndocrinologyCitation Excerpt :A handful of studies have used 13C-MRS to measure the effect of carbohydrate ingestion on the rate of post-exercise hepatic glycogen resynthesis in athletes without diabetes26,56,57 (see the section on effects of the type and form of carbohydrates on post-exercise recovery and glycaemia). Although there are no data on hepatic glycogen metabolism during the post-exercise period in athletes with type 1 diabetes, Bally and colleagues58 found similar hepatic and intramyocellular glycogen stores between adults with well-controlled type 1 diabetes and a group of matched individuals without type 1 diabetes under standard resting conditions. Future research should aim to use these techniques to investigate optimal strategies to maximise hepatic glycogen resynthesis after long periods of endurance exercise in athletes with type 1 diabetes.
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- 1
Address: Departments of Clinical Research and Radiology, University Hospital and Inselspital, University of Bern, Switzerland.
- 2
These authors contributed equally to this work.