To the editor
We read with interest the recent paper by Kłak et al1 published in Polish Archives of Internal Medicine (Pol Arch Intern Med). We would like to thank the authors for their timely contribution to the literature via a review of the current evidence for the impact of continuous glucose monitoring (CGM) on patient-reported outcomes, including fear of hypoglycemia. Overall, while the authors presented interesting results suggesting that CGM reduces fear of hypoglycemia and improves the quality of life, we have some concerns, as outlined below.
First, while the authors declared their population of interest to be individuals with type 1 diabetes, they included a study2 with a mixed sample of patients both with type 1 and type 2 diabetes, without discussing the trade-off between including studies with participants not exactly meeting the eligibility criteria and the loss of data when excluding them.3
Additionally, 3 of the 6 studies included in the analysis of the Hypoglycemia Fear Survey-Worry subscale scores do not seem to satisfy the intervention criteria presented in the Methods section. The authors defined the intervention as any type of CGM system, and conventional self-measurement of blood glucose using glucometers as the control. Kropf et al (Diabet Med, 2017) compared sensor-augmented pump with an artificial pancreas system (2 advanced diabetes technologies enabling a connection between a CGM system and an insulin pump),4 Reddy et al (Diabetes Technol Ther, 2018) considered an intermittently scanned CGM (flash glucose monitor) as a control compared with real-time CGM (rtCGM) as the intervention, and Walker et al (J Diabetes Sci Technol, 2014) compared a fully functional rtCGM as a control to a blinded rtCGM (intervention).
Other concerns pertaining to this manuscript include not accounting for baseline levels of fear of hypoglycemia in the meta-analysis, which could be misleading. For example, when considering the study by Reddy et al, the authors of the review reported higher fear in the intervention group compared with controls, without acknowledging that baseline fear of hypoglycemia was higher in the intervention group.
Furthermore, 3 studies were excluded from the review due to the lack of a control group, yet one of these was a randomized, controlled, crossover study (Hommel et al; Acta Diabetol, 2014), which indicates the presence of a control group. The other 2 studies were prospective, observational studies with a total of 694 adult participants (Charleer et al; J Clin Endocrinol Metab, 2018 and Nørgaard et al; Diabetes Technol Ther, 2013). The authors included a cross-sectional study,2 yet decided to exclude these 2 prospective studies that could add real-life insights on the temporality of the association observed between technology use and the outcomes.
In conclusion, while Kłak et al1 presented interesting results summarizing some of the literature data on the important topic of diabetes technologies and fear of hypoglycemia, certain methodological aspects might need further consideration.
Meryem K. Talbo, DtP, MSc, PhD(c), School of Human Nutrition, McGill University, 21111 Lakeshore, Ste-Anne-de-Bellevue, Quebec, Canada H9X 3V9, phone: +1 514 398 7843, email: meryem.talbo@mail.mcgill.ca
February 28, 2022.
Meryem K. Talbo, Tricia Peters, Anne-Sophie Brazeau, Remi Rabasa-Lhoret, Jean-Francois Yale (MKT and A-SB: School of Human Nutrition, McGill University, Montreal, Quebec, Canada; TP: Lady Davis Institute of Medical Research, Jewish General Hospital, Montreal, Quebec, Canada; Division of Endocrinology, Department of Medicine, The Jewish General Hospital, McGill University, Montreal, QC, Canada; RR-L: Institut de Recherches Cliniques de Montréal, Université de Montreal, Montreal, Quebec, Canada; J-FY: Division of Endocrinology and Metabolism, McGill University Health Center, McGill University, Montreal, Quebec, Canada)
The authors of this letter are currently working on a review on the topic of diabetes technologies use and impact on fear of hypoglycemia in type 1 diabetes, registered as PROSPERO 2021 CRD42021253618.
Talbo MK, Peters T, Brazeau A-S, et al. Can continuous glucose monitoring technology reduce fear of hypoglycemia in people with type 1 diabetes? Pol Arch Intern Med. 2022; 132: 16209. doi:10.20452/pamw.16209
- 1.
- Kłak A, Mańczak M, Owoc J, Olszewski R. Impact of continuous glucose monitoring on improving emotional well-being among adults with type 1 diabetes mellitus: a systematic review and meta-analysis. Pol Arch Intern Med. 2021; 131: 808-818.Crossref
- 2.
- Polonsky WH, Peters AL, Hessler D. The impact of real-time continuous glucose monitoring in patients 65 years and older. J Diabetes Sci Technol. 2016; 10: 892-897.Crossref
- 3.
- McKenzie JE, Brennan SE, Ryan RE, et al. Defining the criteria for including studies and how they will be grouped for the synthesis. In: Higgins JPT, Thomas J, Chandler J, et al, eds. Cochrane Handbook for Systematic Reviews of Interventions. 2nd Edition. Chichester (UK): John Wiley & Sons; 2019: 33-65.
- 4.
- American Diabetes Association. 7. Diabetes technology: standards of medical care in diabetes – 2021. Diabetes Care. 2021; 44 (Suppl 1): S85-S99.Crossref