Running with Type 1 Diabetes: A Case Report on the Benefit of Sensor Technology

Round 1

Reviewer 1 Report

Diabetology-1629378-peer-review-v1

 

I am thankful for being given the opportunity to review this interesting case report titled “Running with type 1 diabetes: a case report on the benefit of sensor technology” by Chellan and Muller. The authors describe the effects/benefits of continuous glucose monitoring (CGM) in a 38-year-old female (for about two years) whose medical history has been charted for about 20 years. While the case report is overall well-written, the following points need to be addressed by the authors before this report is considered for publication:

• Abstract: (i) line 16-17 – the CGM benefits was charted over a period of only two years, correct? Whereas the history of the patient has been extensively described (over 20 years)? The statements in the abstract need to be rephrased/made clear for the readers.

(ii) Lines 16-18: while the authors make a case of the positive effects of the patients’ running/physical activity, there is lack of its information/emphasis about it in the case presentation and the discussion per se. This may also add to the novelty of the case report, from an exercise/athletics-sports + T1D management perspective.

• Introduction: lines 25-26 – please revise (CGM was for only for about 2 years).
• Lines 42-43: “For the purposes of this report….”, the sentence reads as if Dexcom G6 was used just for the purpose to write a report and not to manage/improve the patients’ condition. Please revise.
• Lines 52-54: Please include the normal ranges for all parameters.
• Clinical Course and Management: A figure showing a timeline identifying major events charted over the 20-year period would be beneficial for the readers (apart from the HbA1C levels in figure 1). Currently, some key information is missing in the case presentation (only years 2003, 2007 and then a jump to 2016, after which the details are somewhat described). How was her T1D managed between Feb 2007- 06thDec 2016? Was she exercising between this period? What about her running/exercise regime between 2003-2016? Her diet during this period? Agreed the CGM helped in managing her diabetes (2019-2021), but there seems to be a strong drop in the HbA1C levels between 2003 to 2015. This has a short mention (lines 65-70) and requires more explanation.
• Lines 93-94: were there further neurological + vascular complications apart from those described in lines 60-61? Details missing. Furthermore, what sort of vascular complications are the authors talking about – there is no mention of any vascular anomalies in the case presentation.
• Details of carbohydrate/diet adjustments during her improvement in HbAC1 levels (2019-2021), in correlation with her intense exercise regimen is missing? What about prior to this timeframe?
• Lines 94-97: what was patients’ body weight/BMI since 2003? Please try to include it in a revised figure 1?
• Lines 133-137: the references used is for patients with T2D and not T1D, please use appropriate references.
• Lines 150-151: “….and improved quality of life”…how? Where is QOL described earlier in the text? A little more explanation in the introduction/case/discussion texts is warranted to make such conclusion remarks.

 

Some minor corrections:

• Line 131: amputation of death (does not make sense)?
• Authors may want to consider using real-time CGM, instead of just CGM throughout in the text
• Ensure the correctness of the references

Author Response

The authors would like to extend our thanks for the extensive review of our manuscript and wish to herewith submit a detailed revision thereof, with the responses to reviewers submitted in this document in italicized text.

• Abstract: (i) line 16-17 – the CGM benefits was charted over a period of only two years, correct? Whereas the history of the patient has been extensively described (over 20 years)? The statements in the abstract need to be rephrased/made clear for the readers.

The period of CGM usage was clearly stated in the abstract, i.e., 2 years of the 20 years of patient history that is report.

 

• (ii) Lines 16-18: while the authors make a case of the positive effects of the patients’ running/physical activity, there is lack of its information/emphasis about it in the case presentation and the discussion per se. This may also add to the novelty of the case report, from an exercise/athletics-sports + T1D management perspective.

More emphasis has been placed on the positive effects of running/physical activity in both the clinical course and management, and the discussion. This is an extremely important aspect of diabetes management and care.

 

• Introduction: lines 25-26 – please revise (CGM was for only for about 2 years).

Amended.

 

• Lines 42-43: “For the purposes of this report….”, the sentence reads as if Dexcom G6 was used just for the purpose to write a report and not to manage/improve the patients’ condition. Please revise.

Amended.

 

• Lines 52-54: Please include the normal ranges for all parameters.

Normal ranges included.

 

• Clinical Course and Management: A figure showing a timeline identifying major events charted over the 20-year period would be beneficial for the readers (apart from the HbA1C levels in figure 1). Currently, some key information is missing in the case presentation (only years 2003, 2007 and then a jump to 2016, after which the details are somewhat described). How was her T1D managed between Feb 2007- 06thDec 2016? Was she exercising between this period? What about her running/exercise regime between 2003-2016? Her diet during this period? Agreed the CGM helped in managing her diabetes (2019-2021), but there seems to be a strong drop in the HbA1C levels between 2003 to 2015. This has a short mention (lines 65-70) and requires more explanation. Figure amended and additional information requested added in text.

 

• Lines 93-94: were there further neurological + vascular complications apart from those described in lines 60-61? Details missing. Furthermore, what sort of vascular complications are the authors talking about – there is no mention of any vascular anomalies in the case presentation.

Information included.

 

• Details of carbohydrate/diet adjustments during her improvement in HbAC1 levels (2019-2021), in correlation with her intense exercise regimen is missing? What about prior to this timeframe? Information included.

 

• Lines 94-97: what was patients’ body weight/BMI since 2003? Please try to include it in a revised figure 1?

Unfortunately, these records are unavailable.

 

• Lines 133-137: the references used is for patients with T2D and not T1D, please use appropriate references.

References and text amended.

 

• Lines 150-151: “….and improved quality of life”…how? Where is QOL described earlier in the text? A little more explanation in the introduction/case/discussion texts is warranted to make such conclusion remarks.

Improved quality of life is subjective in this case and the sentence has been amended.

 

• Line 131: amputation of death (does not make sense)?

Corrected.

 

• Authors may want to consider using real-time CGM, instead of just CGM throughout in the text. Amended.
• Ensure the correctness of the references.

References have been amended.

Author Response File: Author Response.docx

Reviewer 2 Report

The manuscript entitled Running with type 1 diabetes: a case report on the benefit of sensor technology describes a case report for the usage of continuous glucose monitor in one brittle type 1 diabetic female. It is an interesting case, as it reports the usage of CGM technology during exercise. However, I am afraid the exercises sessions could have been more detailed, I have not noticed descriptions about the intensity of the running sessions, for instance.

It is an interesting manuscript, but in my opinion, there are a few issues to be addressed in order to improve readability.

It bothers me that the x-axis of Figure 1 (a) that reports HbA1C from Jan/2003 to July/2021 is not in scale. The interval between Jan/2003 to Feb/2007 (4 years) is the same as two consecutive measures on Nov/20 to Feb/21 (3 months). I noticed that oldest data is available in lower amount of samples, but perhaps it is possible to illustrate the graph in evenly distributed per year in the x-axis.

 

Patient has only started using Dexcom G6 CGM on 2019, when it became available in South Africa. Yet, after mentioning that, the authors report the two fold reduction in HbA1C from 13.2% in Jan/2003 to 7.4% in July/2021. Perhaps lines 71 to 79 should be rephrased, clarifying that the reduction in HbA1C that occurred from 2003 to 2019 was due to the adjustments in insulin therapy. Then, later, when Dexcom G6 became available, it occurred the other second reduction of 2%.

 

Authors report a reduction in total insulin dosage from 57U in January 2003 to 45U currently. However, I am not sure if the patient used to be a runner back in 2003. It would be interesting to see the reduction or adjustments and total insulin reduction through the whole period of analysis.

 

In my opinion, this manuscript should undergo revisions, both in the organization of the manuscript and improvement of the figures. In addition, improvements in the methodology and presentation of results are also welcome. If the authors want to express in the title the benefits of sensor technology in running, it should be evidenced in the manuscript, and perhaps separated from the period when no sensors where considered, or the running activity of the patient is unknown. For that period, perhaps, only the manual insulin adjustments and corresponding achievements in HBA1C should be shown.

 

Author Response

The authors would like to extend our thanks for the extensive review of our manuscript and wish to herewith submit a detailed revision thereof, with the responses to reviewers submitted in this document in italicized text.

• The manuscript entitled Running with type 1 diabetes: a case report on the benefit of sensor technology describes a case report for the usage of continuous glucose monitor in one brittle type 1 diabetic female. It is an interesting case, as it reports the usage of CGM technology during exercise. However, I am afraid the exercises sessions could have been more detailed, I have not noticed descriptions about the intensity of the running sessions, for instance.

Additional information regarding exercise has been included in several sections of the paper due to its significance.

 

• It is an interesting manuscript, but in my opinion, there are a few issues to be addressed in order to improve readability.

Several in-text changes have been made to improve readability.

 

• It bothers me that the x-axis of Figure 1 (a) that reports HbA1C from Jan/2003 to July/2021 is not in scale. The interval between Jan/2003 to Feb/2007 (4 years) is the same as two consecutive measures on Nov/20 to Feb/21 (3 months). I noticed that oldest data is available in lower amount of samples, but perhaps it is possible to illustrate the graph in evenly distributed per year in the x-axis.

This has been amended accordingly.

 

• Patient has only started using Dexcom G6 CGM on 2019, when it became available in South Africa. Yet, after mentioning that, the authors report the two fold reduction in HbA1C from 13.2% in Jan/2003 to 7.4% in July/2021. Perhaps lines 71 to 79 should be rephrased, clarifying that the reduction in HbA1C that occurred from 2003 to 2019 was due to the adjustments in insulin therapy. Then, later, when Dexcom G6 became available, it occurred the other second reduction of 2%. This information has been included throughout the document.

 

• Authors report a reduction in total insulin dosage from 57U in January 2003 to 45U currently. However, I am not sure if the patient used to be a runner back in 2003. It would be interesting to see the reduction or adjustments and total insulin reduction through the whole period of analysis. Unfortunately, insulin usage records are not available over the entire reporting period. However, more detail into exercise regimen has been included.

 

• In my opinion, this manuscript should undergo revisions, both in the organization of the manuscript and improvement of the figures. In addition, improvements in the methodology and presentation of results are also welcome. If the authors want to express in the title the benefits of sensor technology in running, it should be evidenced in the manuscript, and perhaps separated from the period when no sensors where considered, or the running activity of the patient is unknown. For that period, perhaps, only the manual insulin adjustments and corresponding achievements in HBA1C should be shown.

The manuscript has been extensively revised, including figure 1a. Special emphasis has been placed on the beneficial effect specifically of CGM usage in reducing the HbA1C values that were persistently above 8.0-8.5%.

Author Response File: Author Response.docx

Reviewer 3 Report

The authors describe here a case of brittle diabet, which is quite rare and severe pathology. This type of diabetes is especially difficult to manage and it often disrupts everyday life of patients.  Thus, the positive results of clinical management based on advanced monitoring technology are promising for endocrinological specialists and their patients.

However, on my point of view, the study lacks some additional clinical measurements for diagnosis confirmation and monitoring of patient status. Thus, the authors did not provide insulin and glucose levels, insulin antibodies status, the appearance of disease complications after the diagnosing of brittle diabetes in patients. Moreover, the patient's CGM do not look like brittle diabetes type 1, so the authors need a stronger evidence base to confirm the correct diagnosis.

It would be also more informative, if the authors specified the presence or absence of a diabetes family history 

Author Response

The authors would like to extend our thanks for the extensive review of our manuscript and wish to herewith submit a detailed revision thereof, with the responses to reviewers submitted in this document in italicized text.

• The authors describe here a case of brittle diabet, which is quite rare and severe pathology. This type of diabetes is especially difficult to manage and it often disrupts everyday life of patients.  Thus, the positive results of clinical management based on advanced monitoring technology are promising for endocrinological specialists and their patients.

However, on my point of view, the study lacks some additional clinical measurements for diagnosis confirmation and monitoring of patient status. Thus, the authors did not provide insulin and glucose levels, insulin antibodies status, the appearance of disease complications after the diagnosing of brittle diabetes in patients. Moreover, the patient's CGM do not look like brittle diabetes type 1, so the authors need a stronger evidence base to confirm the correct diagnosis.

The appearance of disease complications after diagnosing brittle diabetes has been included, however the diagnosis thereof remains subjective. The patients CGM data is merely an overview, however daily graph records show the gross daily fluctuations. Unfortunately, insulin antibody status of the patient is not recorded.

• It would be also more informative, if the authors specified the presence or absence of a diabetes family history.

Family history has been included.

Author Response File: Author Response.docx

Round 2

Reviewer 3 Report

Despite the authors made the changes in the manuscript, the study still lacks some important measurements, which should advocate the accuracy of diagnosis and subsequent treatment.

The authors confirmed, that they have no data related to insulin antibody status.  Then, was the basic metabolic panel performed? Urinalysis nitroprusside reaction to measure levels of serum acetone and acetate? genetic testing?

Author Response

Dear Sir/Madam,

 

Thank you for your feedback. The data presented in this manuscript represents all the accessible data for the patient. The cholesterol/triglyceride serum content of the patient was reported herein with the latest blood work.

 

We sincerely hope that this information suffices.