CGM Glucose Excursion Parameters - Analysis of Baseline Data

4.1 Analysis of Baseline Data

4.1.12 CGM Glucose Excursion Parameters

As described in Section 2.10, four CGM based glucose excursion parameters were devised and the results at baseline for each subject (n = 45) are seen in Table 7.

Table 7: Summary of CGM Glucose Parameters - Baseline

MEAN Baseline Av Gl (mmol/l) MEAN Baseline AvGl excursion from Av (mmol/l) MEAN Baseline Av above norm Gl (mmol/l) MEAN Baseline Av Gl excursion from norm Gl (mmol/l) N Valid 45 45 45 45 Missing 0 0 0 0 Mean 6.73 .99 2.23 2.48 Std. Deviation .66 .34 .66 .65 Range 3.13 1.86 3.13 3.02 Minimum 5.27 .36 .77 1.03 Maximum 8.40 2.22 3.90 4.05

The CGM Mean Average Glucose for the baseline data (n = 45) was 6.73 mmol/l, with a maximum and a maximum and minimum CGM Mean Average Glucose of 8.40 and 5.27 mmol/l, respectively (Table 7; Figure respectively (Table 7; Figure 29: Baseline Subjects: CGM Mean Average Glucose (mmol/l)

). The CGM Mean Average Glucose Excursion from the Average Glucose (mmol/l) for the baseline data (n = 45) was 1.0 mmol/l, with a maximum and minimum CGM Mean Average Excursion from the Average Glucose of 2.22 and 0.36 mmol/l, respectively (Table 7, Error! Reference source not found.). The CGM Mean Average Glucose above Normal Glucose (mmol/l) for the baseline data (n = 45) was 2.23 mmol/l, with a maximum and mmol/l, with a maximum and minimum CGM Mean Average Glucose above Normal Glucose of 3.90 and 0.77 Glucose of 3.90 and 0.77 mmol/l, respectively (Table 7; Figure 31: Baseline Subjects CGM: Mean Average Glucose above Normal Glucose (mmol/l)

). The CGM Mean Average Glucose Excursion from Normal Glucose (mmol/l) for the baseline data (n = 45) was 2.49 mmol/l, with a maximum and minimum CGM Mean Average Glucose Excursion from Normal Glucose of 4.05 and 1.03 mmol/l, respectively (Table 7, Figure 32: Baseline Subjects CGM: Mean Average Glucose Excursion from Normal Glucose (mmol/l)

Figure 29: Baseline Subjects: CGM Mean Average Glucose (mmol/l)

-The CGM Mean Average Glucose for the baseline data (n = 45) was 6.73 mmol/l, with a maximum and minimum CGM Mean Average Glucose of 8.40 and 5.27 mmol/l, respectively.

Figure 30: Baseline Subjects: CGM Mean Average Glucose Excursion from the Average Glucose (mmol/l)

-The CGM Mean Average Glucose Excursion from the Average Glucose (mmol/l) for the baseline data (n = 45) was 1.0 mmol/l, with a maximum and minimum CGM Mean Average Excursion from the Average Glucose of 2.22 and 0.36 mmol/l, respectively

Figure 31: Baseline Subjects CGM: Mean Average Glucose above Normal Glucose (mmol/l)

-The CGM Mean Average Glucose above Normal Glucose (mmol/l) for the baseline data (n = 45) was 2.23 mmol/l, with a maximum and minimum CGM Mean Average Glucose above Normal Glucose of 3.90 and 0.77 mmol/l, respectively.

Figure 32: Baseline Subjects CGM: Mean Average Glucose Excursion from Normal Glucose (mmol/l)

-The CGM Mean Average Glucose Excursion from Normal Glucose (mmol/l) for the baseline data (n = 45) was 2.49

mmol/l, with a maximum and minimum CGM Mean Average Glucose Excursion from Normal Glucose of 4.05 and 1.03 mmol/l, respectively.

4.1.13 CGM Profiles

CGM was conducted on all the subjects at baseline (n= 45). Each CGM profile (Sensor Modal Day) was then Modal Day) was then inspected by eye and the profiles were placed in one of three groups, according to the groups, according to the “flatness” or “peakiness” of the profile. The three groups were labelled least labelled least variability, as illustrated in Figure 33: CGM Profile (SAP) - Least Variability: (a subject illustration)

, medium variability as illustrated in Figure 34: CGM Profile (SAP) - Medium Variability: (a subject illustration)

and most variability, as illustrated in Figure 35: CGM Profiles (SAP) - Most Variability: (a subject illustration)

A representative example of each of these three different profiles described above can be seen in the illustrations below. The CGM profiles were inspected blindly by the PI (CGM profiles SAP) and by an independent observer (CGM Profiles PUMP); the independent observer was a Lead Diabetic Specialist Nurse. CGM profiles for each subject at baseline can be seen in the APPENDIX, as APPENDIX 2: Least Variability; APPENDIX 3 – medium variability and APPENDIX 4 – most variability.

Figure 33: CGM Profile (SAP) - Least Variability: (a subject illustration)

-Sensor Modal Day demonstrated all of the glucose data over a 24 hour period from subject IPRO-05a, with each day represented as separate plot line in a different colour.

Figure 34: CGM Profile (SAP) - Medium Variability: (a subject illustration)

-Sensor Modal Day demonstrated all of the glucose data over a 24 hour period from subject IPRO-38a, with each day

Figure 35: CGM Profiles (SAP) - Most Variability: (a subject illustration)

-Sensor Modal Day demonstrated all of the glucose data over a 24 hour period, from subject ipro-06a, with each day

represented as separate plot line in a different colour.

One can see that when the CGM (SAP) profiles were inspected (Table 8), 20% (n = 9) of them were observed to demonstrate least variability, 48.9% (n = 22) were observed to demonstrate medium variability and 31.1% (n = 14) were observed to demonstrate most variability. These results closely mirrored the independent observers assessment of variability (

Table 9), which demonstrated 22.2% (n = 10) of the CGM (PUMP) profiles were observed to demonstrate least variability, 46.7% (n = 21) were observed to demonstrate medium variability and 31.1% (n = 14) were observed to demonstrate most variability. When this was looked at in more detail, there was only a single disagreement between assessors. The investigator placed one less CGM profile in the least variability category, compared to the independent observer (PUMP); the remainder were identical.

Table 8: Baseline Subjects CGM Profiles (SAP)

Frequency %

least variability 9 20.0

medium variability 22 48.9

most variability 14 31.1

Total 45 100.0

74 Frequency % least variability 10 22.2 medium variability 21 46.7 most variability 14 31.1 Total 45 100.0

At baseline, each of the four CGM parameters described in Section 2.10, were looked at with regard to their with regard to their relationship with the CGM profile groups. As both the PI (SAP) and the independent the independent observer (PUMP) findings were very similar, with regard to the degree of observed glucose of observed glucose variation in the subjects CGM profiles, for the purpose of this study, the investigators study, the investigators observations of CGM Profiles (SAP) were used in the remaining analysis. The CGM analysis. The CGM parameter Mean Baseline Average Glucose was 6.14 mmol/l for least variability CGM least variability CGM profile (SAP), rising to 6.70 mmol/l for medium variability CGM profile (SAP) up to profile (SAP) up to 7.17 mmol/l for most variability CGM profile (SAP) (Figure 36: Summary: Baseline Subjects CGM Parameters v CGM Profiles (SAP)

). The CGM parameter Mean Baseline Average Glucose Excursion from Average (mmol/l) was 0.65 mmol/l for least variability CGM profile (SAP), rising to 0.92 mmol/l for medium variability CGM profile (SAP) up to 1.34 mmol/l for most variability CGM profile (SAP) (Figure 36: Summary: Baseline Subjects CGM Parameters v CGM Profiles (SAP)

). The CGM parameter Mean Baseline Average Glucose above Normal Glucose (mmol/l) was 1.64 mmol/l for least variability CGM profile (SAP), rising to 2.20 mmol/l for medium variability CGM profile (SAP), up to 2.67 mmol/l for most variability CGM profile (SAP) (Figure 36: Summary: Baseline Subjects CGM Parameters v CGM Profiles (SAP)

). The CGM parameter Mean Baseline Average Glucose Excursion from Normal Glucose (mmol/l) was 1.81 mmol/l for least variability CGM profile (SAP), rising to 2.41 mmol/l for medium variability CGM profile (SAP), up to 3.04 mmol/l for most variability CGM profile (SAP) (Figure 36: Summary: Baseline Subjects CGM Parameters v CGM Profiles (SAP)

Figure 36: Summary: Baseline Subjects CGM Parameters v CGM Profiles (SAP)

-At baseline, for CGM profile (SAP): the CGM parameter Mean Baseline Average Glucose was 6.14 mmol/l for least variability, rising to 6.70 mmol/l for medium variability and up to 7.17 mmol/l for most variability; the CGM parameter Mean Baseline Average Glucose Excursion from Average (mmol/l) was 0.65 mmol/l for least variability, rising to 0.92 mmol/l for medium variability and up to 1.34 mmol/l for most variability; the CGM parameter Mean Baseline Average Glucose above Normal Glucose (mmol/l) was 1.64 mmol/l for least variability, rising to 2.20 mmol/l for medium variability and up to 2.67 mmol/l for most variability; the CGM parameter Mean Baseline Average Glucose Excursion from Normal Glucose (mmol/l) was 1.81 mmol/l for least variability, rising to 2.41 mmol/l for medium variability and up to 3.04 mmol/l for most variability.

At baseline, each of the four CGM parameters described in Section 2.10, were looked at with regard to their with regard to their relationship with the CGM profile groupings. As the degree of variability of the subject variability of the subject CGM profiles (SAP) observed by eye, increased from least variability to most variability to most variability, the mean of each of the four CGM parameters was observed to increase also, as observed to increase also, as discussed above, which can be seen from the mean plots (Figure 37: Summary Baseline Subjects CGM Parameters v CGM Profile (SAP) - Mean Plots

) (Figure 38: Summary Baseline Subjects CGM Parameters v CGM Profiles (SAP) - Mean Plots ) (Figure 39: Summary Baseline Subjects CGM Parameters v CGM Profiles (SAP) - Mean Plots ) (Figure 40: Summary Baseline Subjects CGM Parameters v CGM Profiles (SAP) - Mean Plots ) respectively.

Figure 37: Summary Baseline Subjects CGM Parameters v CGM Profile (SAP) - Mean Plots

-As the degree of variability of the subject CGM profiles (SAP) observed by eye, increased from least variability to most variability, the mean of MEAN Baseline Average Glucose (mmol/l) was also observed to increase.

Figure 38: Summary Baseline Subjects CGM Parameters v CGM Profiles (SAP) - Mean Plots

-As the degree of variability of the subject CGM profiles (SAP) observed by eye, increased from least variability to most variability, the mean of MEAN Baseline Average Glucose excursion from Average (mmol/l) was also observed to increase.

Figure 39: Summary Baseline Subjects CGM Parameters v CGM Profiles (SAP) - Mean Plots

-As the degree of variability of the subject CGM profiles (SAP) observed by eye, increased from least variability to most variability, the mean of MEAN Baseline Average above normal Glucose (mmol/l) was also observed to increase.

Figure 40: Summary Baseline Subjects CGM Parameters v CGM Profiles (SAP) - Mean Plots

In document Continuous Subcutaneous Glucose Monitoring (CGM) to predict progression from abnormal glucose tolerance (Pre-diabetes) to Type 2 Diabetes Mellitus (Page 68-77)