1Division of Endocrinology and Metabolism, Department of Medicine, Yonsei University Wonju College of Medicine, Wonju, Korea
2Division of Endocrinology and Metabolism, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
Copyright © 2020 Korean Diabetes Association
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CONFLICTS OF INTEREST
No potential conflict of interest relevant to this article was reported.
TIR (70–180 mg/dL) | Vigersky et al.a [23] (n=1,137 participants with T1DM or T2DM) | Beck et al.b [22] at baseline (n=455 participants with T1DM) | Beck et al.b [22] in month 6 (n=545 participants with T1DM) | Fabris et al.c [24] (n=168 participants with T1DM) |
---|---|---|---|---|
20% | 10.6 | 9.4 | 8.8 | 9.3 |
30% | 9.8 | 8.9 | 8.4 | 8.9 |
40% | 9.0 | 8.4 | 8.0 | 8.5 |
50% | 8.3 | 7.9 | 7.6 | 8.1 |
60% | 7.5 | 7.4 | 7.2 | 7.7 |
70% | 6.7 | 7.0 | 6.8 | 7.3 |
80% | 5.9 | 6.5 | 6.4 | 6.9 |
90% | 5.1 | 6.0 | 6.0 | 6.5 |
Baseline HbA1c, % | NA | 7.5±1.0 | 7.2±0.8 | NA |
Equation | HbA1c=12.32–0.081×TIR | HbA1c=10.31–0.048×TIR | HbA1c=9.65–0.041×TIR | HbA1c=10.12–0.04×TIR |
Every 10% increase in TIR | ~0.8% HbA1c reduction | ~0.5% HbA1c reduction | ~0.4% HbA1c reduction | ~0.4% HbA1c reduction |
HbA1c, glycosylated hemoglobin; CGM, continuous glucose monitoring; TIR, time in range; T1DM, type 1 diabetes mellitus; T2DM, type 2 diabetes mellitus; NA, not applicable.
a Data sets were from 18 clinical trials using CGM for a minimum of 3 days,
b Data used in analyses were from four randomized trials using CGM for a minimum of 10 days for baseline and 14 days in month 6,
c Linear regression analysis was used to analyze 3-month full CGM data for this equation.
Study | Populations | Outcome | Results |
---|---|---|---|
Beck et al. (2019) [34] | 1,440 Patients with T1DM in DCCT | Retinopathy, albuminuria | HRs for retinopathy and microalbuminuria by TIR; 7-point SMBG (each 10% decrease in TIR): 1.64 (1.51–1.78) and 1.40 (1.25–1.56) |
Lu et al. (2018) [30] | 3,262 Patients with T2DM | Retinopathy | OR for any retinopathy by TIR; CGM (each 10% increase in TIR): 0.92 (0.88–0.96) |
Lu et al. (2020) [29] | 2,215 Patients with T2DM | CIMT | OR for CIMT by TIR; CGM (each 10% increase in TIR): 0.936 (0.878–0.998) |
Yoo et al. (2020) [33] | 866 Patients with T2DM | Albuminuria | OR for albuminuria by TIR; CGM (each 10% increase in TIR): 0.94 (0.88–0.99) |
Ranjan et al. (2020) [31] | 26 Patients with T1DM with SAP | Albuminuria | HR for albuminuria by TIR; CGM (each 10% increase in TIR): 0.81 (0.72–0.90) |
Yang et al. (2020) [32] | 364 Patients with diabetic polyneuropathy | Painful diabetic polyneuropathy | OR for painful diabetic polyneuropathy by TIR; CGM (quartile): 2.66 (1.16–6.10) |
TIR, time in range; T1DM, type 1 diabetes mellitus; DCCT, Diabetes Control and Complications Trial; HR, hazard ratio; SMBG, self-monitoring blood glucose; T2DM, type 2 diabetes mellitus; OR, odds ratio; CGM, continuous glucose monitoring; CIMT, carotid intima-media thickness; SAP, sensor-augmented insulin pump.
Professional CGM | Personal CGM | |
---|---|---|
Methods for obtaining glucose metrics | Blind, retrospective | Real-time (RT) observation or flash glucose monitoring (FGM) |
|
||
Duration | Intermittent use by healthcare providers | Continuous use by patients |
|
||
Device available in Korea | Medtronic ipro2 |
Medtronic Guardian Connect Dexcom G5, G6 (possible sooner) Freestyle Libre |
|
||
Advantages | The results cannot bias patient and investigator use of trial products because they are unaware of the glucose values. | Patient can directly adjust their diet and exercise behavior or insulin dose with adequate patient education and training. |
Healthcare providers can make appropriate therapy changes with T1DM and even T2DM patients with unrecognized hypo- and hyperglycemia. | Useful for long-term monitoring in patients who are on regimens with basal and prandial insulin. | |
Both provide optimal therapy adjustment | ||
|
||
Limitations | No alarms for hypo- and hyperglycemia | Clinical trial results may be affected by response to real-time data (e.g., temporary behavior change, insulin dose adjustment, medication inherence, unethical behavior). |
Not allowed for long-term monitoring | Alarm or calibration fatiguea, cost | |
Time consuming for reviewing CGM data |
TIR (70–180 mg/dL) | Vigersky et al. |
Beck et al. |
Beck et al. |
Fabris et al. |
---|---|---|---|---|
20% | 10.6 | 9.4 | 8.8 | 9.3 |
30% | 9.8 | 8.9 | 8.4 | 8.9 |
40% | 9.0 | 8.4 | 8.0 | 8.5 |
50% | 8.3 | 7.9 | 7.6 | 8.1 |
60% | 7.5 | 7.4 | 7.2 | 7.7 |
70% | 6.7 | 7.0 | 6.8 | 7.3 |
80% | 5.9 | 6.5 | 6.4 | 6.9 |
90% | 5.1 | 6.0 | 6.0 | 6.5 |
Baseline HbA1c, % | NA | 7.5±1.0 | 7.2±0.8 | NA |
Equation | HbA1c=12.32–0.081×TIR | HbA1c=10.31–0.048×TIR | HbA1c=9.65–0.041×TIR | HbA1c=10.12–0.04×TIR |
Every 10% increase in TIR | ~0.8% HbA1c reduction | ~0.5% HbA1c reduction | ~0.4% HbA1c reduction | ~0.4% HbA1c reduction |
Study | Populations | Outcome | Results |
---|---|---|---|
Beck et al. (2019) [ |
1,440 Patients with T1DM in DCCT | Retinopathy, albuminuria | HRs for retinopathy and microalbuminuria by TIR; 7-point SMBG (each 10% decrease in TIR): 1.64 (1.51–1.78) and 1.40 (1.25–1.56) |
Lu et al. (2018) [ |
3,262 Patients with T2DM | Retinopathy | OR for any retinopathy by TIR; CGM (each 10% increase in TIR): 0.92 (0.88–0.96) |
Lu et al. (2020) [ |
2,215 Patients with T2DM | CIMT | OR for CIMT by TIR; CGM (each 10% increase in TIR): 0.936 (0.878–0.998) |
Yoo et al. (2020) [ |
866 Patients with T2DM | Albuminuria | OR for albuminuria by TIR; CGM (each 10% increase in TIR): 0.94 (0.88–0.99) |
Ranjan et al. (2020) [ |
26 Patients with T1DM with SAP | Albuminuria | HR for albuminuria by TIR; CGM (each 10% increase in TIR): 0.81 (0.72–0.90) |
Yang et al. (2020) [ |
364 Patients with diabetic polyneuropathy | Painful diabetic polyneuropathy | OR for painful diabetic polyneuropathy by TIR; CGM (quartile): 2.66 (1.16–6.10) |
Professional CGM | Personal CGM | |
---|---|---|
Methods for obtaining glucose metrics | Blind, retrospective | Real-time (RT) observation or flash glucose monitoring (FGM) |
| ||
Duration | Intermittent use by healthcare providers | Continuous use by patients |
| ||
Device available in Korea | Medtronic ipro2 | Medtronic Guardian Connect Dexcom G5, G6 (possible sooner) Freestyle Libre |
| ||
Advantages | The results cannot bias patient and investigator use of trial products because they are unaware of the glucose values. | Patient can directly adjust their diet and exercise behavior or insulin dose with adequate patient education and training. |
Healthcare providers can make appropriate therapy changes with T1DM and even T2DM patients with unrecognized hypo- and hyperglycemia. | Useful for long-term monitoring in patients who are on regimens with basal and prandial insulin. | |
Both provide optimal therapy adjustment | ||
| ||
Limitations | No alarms for hypo- and hyperglycemia | Clinical trial results may be affected by response to real-time data (e.g., temporary behavior change, insulin dose adjustment, medication inherence, unethical behavior). |
Not allowed for long-term monitoring | Alarm or calibration fatigue | |
Time consuming for reviewing CGM data |
HbA1c, glycosylated hemoglobin; CGM, continuous glucose monitoring; TIR, time in range; T1DM, type 1 diabetes mellitus; T2DM, type 2 diabetes mellitus; NA, not applicable. Data sets were from 18 clinical trials using CGM for a minimum of 3 days, Data used in analyses were from four randomized trials using CGM for a minimum of 10 days for baseline and 14 days in month 6, Linear regression analysis was used to analyze 3-month full CGM data for this equation.
TIR, time in range; T1DM, type 1 diabetes mellitus; DCCT, Diabetes Control and Complications Trial; HR, hazard ratio; SMBG, self-monitoring blood glucose; T2DM, type 2 diabetes mellitus; OR, odds ratio; CGM, continuous glucose monitoring; CIMT, carotid intima-media thickness; SAP, sensor-augmented insulin pump.
CGM, continuous glucose monitoring; T1DM, type 1 diabetes mellitus; T2DM, type 2 diabetes mellitus, Limited to Dexcom G5, Guardian connect.