1Division of Endocrinology and Metabolism, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
2Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
Copyright © 2023 Korean Diabetes Association
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (https://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
CONFLICTS OF INTEREST
No potential conflict of interest relevant to this article was reported.
AUTHOR CONTRIBUTIONS
Conception or design: Y.B.L., J.H.K.
Acquisition, analysis, or interpretation of data: Y.B.L., M.K.
Drafting the work or revising: Y.B.L., M.K., J.H.K.
Final approval of the manuscript: Y.B.L., M.K., J.H.K.
FUNDING
None
Characteristic | Total (n=314) | CGM never-users (n=203) | CGM users (n=111) | P value | SMD before matching | SMD after 1:2 PS matching |
---|---|---|---|---|---|---|
Matching variables | ||||||
Ageb, yr | 38.00 (31.00–49.00) | 38.00 (31.00–50.00) | 38.00 (30.00–48.00) | 0.7072 | 0.664 | 0.037 |
Male sex | 137 (43.63) | 91 (44.83) | 46 (41.44) | 0.5630 | 0.194 | 0.068 |
Diabetes durationb, yr | 10.00 (4.00–18.00) | 10.00 (4.00–18.00) | 10.00 (5.00–18.00) | 0.8739 | 0.352 | 0.073 |
|
||||||
Other variables | Missing (n) in CGM never-users | Missing (n) in CGM users | ||||
BMIb, kg/m2 | 22.47 (21.02–24.14) | 22.47 (21.02–24.02) | 22.47 (20.92–24.20) | 0.7339 | 0 | 0 |
Systolic BPa, mm Hg | 121.88±16.28 | 121.62±16.51 | 122.34±15.94 | 0.7230 | 25 | 12 |
Diastolic BPa, mm Hg | 69.66±11.67 | 68.98±11.71 | 70.88±11.55 | 0.1957 | 25 | 12 |
Total daily dose of insulinb, IU | 40.00 (28.10–54.00) | 40.00 (28.00–55.00) | 40.00 (29.00–50.00) | 0.8746 | 1 | 12 |
Use of insulin pump | 16 (5.10) | 12 (5.91) | 4 (3.60) | 0.4341 | 0 | 0 |
Total cholesterolb, mg/dL | 161.00 (141.50–185.00) | 159.00 (142.00–185.00) | 166.00 (141.00–187.00) | 0.2511 | 5 | 1 |
Triglyceridesb, mg/dL | 69.00 (54.00–90.00) | 71.00 (54.00–96.00) | 65.50 (53.00–85.00) | 0.2413 | 6 | 1 |
HDL-Cb, mg/dL | 66.00 (55.00–81.00) | 65.00 (54.00–80.00) | 67.50 (56.00–81.00) | 0.3493 | 6 | 1 |
LDL-Cb, mg/dL | 89.00 (72.00–114.00) | 89.00 (72.00–110.00) | 93.00 (76.00–120.00) | 0.1822 | 6 | 1 |
ASTb, U/L | 20.00 (16.00–24.00) | 20.00 (17.00–25.00) | 19.00 (16.00–23.00) | 0.1078 | 5 | 1 |
ALTb, U/L | 16.00 (11.00–22.50) | 17.00 (11.00–23.00) | 15.00 (10.00–22.00) | 0.1423 | 5 | 1 |
BUNb, mg/dL | 12.90 (10.80–16.80) | 13.05 (10.80–17.10) | 12.80 (10.50–16.20) | 0.3756 | 5 | 1 |
Creatinineb, mg/dL | 0.77 (0.65–0.90) | 0.77 (0.66–0.90) | 0.77 (0.64–0.90) | 0.4402 | 10 | 8 |
eGFRb,c, mL/min/1.73 m2 | 108.70 (92.20–117.40) | 107.80 (91.80–117.20) | 109.80 (95.40–119.20) | 0.3515 | 10 | 8 |
Glycosylated hemoglobinb, % | 7.20 (6.70–8.00) | 7.40 (6.90–8.30) | 7.00 (6.50–7.60) | 0.0005 | 0 | 0 |
Fasting plasma glucoseb, mg/dL | 146.00 (114.00–190.00) | 144.00 (111.00–188.00) | 149.50 (122.00–193.00) | 0.2313 | 40 | 5 |
Glycated albuminb, % | 21.55 (18.60–25.10) | 21.80 (18.90–25.80) | 20.80 (18.50–23.60) | 0.0387 | 26 | 2 |
Cerebral infarction | 1 (0.32) | 0 | 1 (0.90) | 0.3535 | 0 | 0 |
Acute myocardial infarction | 1 (0.32) | 0 | 1 (0.90) | 0.3535 | 0 | 0 |
Diabetic retinopathy | 69 (21.97) | 49 (24.14) | 20 (18.02) | 0.2106 | 0 | 0 |
End-stage renal disease | 23 (7.32) | 15 (7.39) | 8 (7.21) | 0.9528 | 0 | 0 |
Values are presented as median (interquartile range), number (%), or mean±standard deviation. Chi-square test or Fisher’s exact test was applied for categorical variables.
CGM, continuous glucose monitoring; SMD, standardized mean difference; PS, propensity score; BMI, body mass index; BP, blood pressure; HDL-C, high-density lipoprotein cholesterol; LDL-C, low-density lipoprotein cholesterol; AST, aspartate aminotransferase; ALT, alanine aminotransferase; BUN, blood urea nitrogen; eGFR, estimated glomerular filtration rate.
a Continuous variables with normal distributions were compared using Student’s t-test,
b Continuous variables with non-normal distributions were compared using Mann–Whitney U test,
c The Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation was used to calculate the eGFR.
Logistic regression analysis with uncontrolled glycosylated hemoglobin (>8%) as a dependent variable was performed to identify whether CGM use could influence this outcome variable. Model 1: Adjusted for age, sex, diabetes duration and body mass index; Model 2: Adjusted for model 1 plus history of cerebral infarction and acute myocardial infarction during the previous 5 years from baseline, and presence of diabetic retinopathy and end-stage renal disease at baseline; Model 3: Adjusted for model 1 plus use of insulin pump, and estimated glomerular filtration rate.
CGM, continuous glucose monitoring.
Characteristic | Total (n=314) | CGM never-users (n=203) | CGM users (n=111) | P value | SMD before matching | SMD after 1:2 PS matching |
---|---|---|---|---|---|---|
Matching variables | ||||||
Age |
38.00 (31.00–49.00) | 38.00 (31.00–50.00) | 38.00 (30.00–48.00) | 0.7072 | 0.664 | 0.037 |
Male sex | 137 (43.63) | 91 (44.83) | 46 (41.44) | 0.5630 | 0.194 | 0.068 |
Diabetes duration |
10.00 (4.00–18.00) | 10.00 (4.00–18.00) | 10.00 (5.00–18.00) | 0.8739 | 0.352 | 0.073 |
| ||||||
Other variables | Missing (n) in CGM never-users | Missing (n) in CGM users | ||||
BMI |
22.47 (21.02–24.14) | 22.47 (21.02–24.02) | 22.47 (20.92–24.20) | 0.7339 | 0 | 0 |
Systolic BP |
121.88±16.28 | 121.62±16.51 | 122.34±15.94 | 0.7230 | 25 | 12 |
Diastolic BP |
69.66±11.67 | 68.98±11.71 | 70.88±11.55 | 0.1957 | 25 | 12 |
Total daily dose of insulin |
40.00 (28.10–54.00) | 40.00 (28.00–55.00) | 40.00 (29.00–50.00) | 0.8746 | 1 | 12 |
Use of insulin pump | 16 (5.10) | 12 (5.91) | 4 (3.60) | 0.4341 | 0 | 0 |
Total cholesterol |
161.00 (141.50–185.00) | 159.00 (142.00–185.00) | 166.00 (141.00–187.00) | 0.2511 | 5 | 1 |
Triglycerides |
69.00 (54.00–90.00) | 71.00 (54.00–96.00) | 65.50 (53.00–85.00) | 0.2413 | 6 | 1 |
HDL-C |
66.00 (55.00–81.00) | 65.00 (54.00–80.00) | 67.50 (56.00–81.00) | 0.3493 | 6 | 1 |
LDL-C |
89.00 (72.00–114.00) | 89.00 (72.00–110.00) | 93.00 (76.00–120.00) | 0.1822 | 6 | 1 |
AST |
20.00 (16.00–24.00) | 20.00 (17.00–25.00) | 19.00 (16.00–23.00) | 0.1078 | 5 | 1 |
ALT |
16.00 (11.00–22.50) | 17.00 (11.00–23.00) | 15.00 (10.00–22.00) | 0.1423 | 5 | 1 |
BUN |
12.90 (10.80–16.80) | 13.05 (10.80–17.10) | 12.80 (10.50–16.20) | 0.3756 | 5 | 1 |
Creatinine |
0.77 (0.65–0.90) | 0.77 (0.66–0.90) | 0.77 (0.64–0.90) | 0.4402 | 10 | 8 |
eGFR |
108.70 (92.20–117.40) | 107.80 (91.80–117.20) | 109.80 (95.40–119.20) | 0.3515 | 10 | 8 |
Glycosylated hemoglobin |
7.20 (6.70–8.00) | 7.40 (6.90–8.30) | 7.00 (6.50–7.60) | 0.0005 | 0 | 0 |
Fasting plasma glucose |
146.00 (114.00–190.00) | 144.00 (111.00–188.00) | 149.50 (122.00–193.00) | 0.2313 | 40 | 5 |
Glycated albumin |
21.55 (18.60–25.10) | 21.80 (18.90–25.80) | 20.80 (18.50–23.60) | 0.0387 | 26 | 2 |
Cerebral infarction | 1 (0.32) | 0 | 1 (0.90) | 0.3535 | 0 | 0 |
Acute myocardial infarction | 1 (0.32) | 0 | 1 (0.90) | 0.3535 | 0 | 0 |
Diabetic retinopathy | 69 (21.97) | 49 (24.14) | 20 (18.02) | 0.2106 | 0 | 0 |
End-stage renal disease | 23 (7.32) | 15 (7.39) | 8 (7.21) | 0.9528 | 0 | 0 |
Variable | Regression coefficient (β) | Standard error | P value |
---|---|---|---|
Univariable analysis | |||
CGM use | −0.02898 | 0.00813 | 0.0004 |
| |||
Multivariable analysis 1 | |||
CGM use | −0.03407 | 0.00830 | <0.0001 |
Age | 0.00065 | 0.00033 | 0.0488 |
Sex | −0.00973 | 0.00869 | 0.2636 |
BMI | 0.00092 | 0.00141 | 0.5168 |
Systolic BP | −0.00047 | 0.00038 | 0.2235 |
Diastolic BP | 0.00101 | 0.00054 | 0.0647 |
R2, % | 0.0544 | ||
| |||
Multivariable analysis 2 | |||
CGM use | −0.03311 | 0.00880 | 0.0002 |
Age | 0.00036 | 0.00038 | 0.3439 |
Sex | −0.01217 | 0.00914 | 0.1845 |
BMI | 0.00094 | 0.00154 | 0.5410 |
Systolic BP | −0.00004 | 0.00028 | 0.9004 |
Use of insulin pump | −0.03143 | 0.02110 | 0.1375 |
eGFR | −0.00011 | 0.00021 | 0.6057 |
Diabetes duration | −0.00042 | 0.00054 | 0.4321 |
R2, % | 0.0482 |
Variable | CGM non-use (n=203) | CGM use (n=111) | P value |
---|---|---|---|
Uncontrolled glycosylated hemoglobin (>8%) | |||
Unadjusted | 1 (reference) | 0.409 (0.231–0.726) | 0.0023 |
Model 1 | 1 (reference) | 0.350 (0.192–0.640) | 0.0006 |
Model 2 | 1 (reference) | 0.344 (0.188–0.628) | 0.0005 |
Model 3 | 1 (reference) | 0.365 (0.190–0.703) | 0.0026 |
Controlled glycosylated hemoglobin (<7%) | |||
Unadjusted | 1 (reference) | 1.759 (1.117–2.769) | 0.0147 |
Model 1 | 1 (reference) | 2.215 (1.361–3.606) | 0.0014 |
Model 2 | 1 (reference) | 2.220 (1.358–3.627) | 0.0015 |
Model 3 | 1 (reference) | 1.861 (1.119–3.096) | 0.0167 |
CGM metrics | Mean±SD | Median (IQR) | Min–Max |
---|---|---|---|
During recent 30 days (n=87) | |||
Percentage of time CGM is active, % | 87.86±12.75 | 91.45 (83.00–96.60) | 16.70–98.70 |
Mean glucose, mg/dL | 163.09±30.11 | 161.00 (144.00–184.50) | 103.00–262.00 |
Glycemic variability, %CV | 36.63±5.46 | 36.90 (33.70–39.58) | 21.20–49.00 |
Time in range (70–180 mg/dL), % | 62.45±16.63 | 64.20 (51.73–72.43) | 9.20–97.50 |
Time above range >180 mg/dL | 33.78±17.76 | 31.00 (23.03–46.70) | 1.80–87.10 |
Time above range >250 mg/dL | 12.07±13.26 | 7.30 (4.40–14.30) | 0.30–86.00 |
Time below range <70 mg/dL | 3.76±3.71 | 2.20 (1.00–5.65) | 0.00–16.00 |
Time below range <54 mg/dL | 1.00±1.48 | 0.40 (0.13–1.30) | 0.00–8.00 |
No. of participants with time in range >70% (%) | 28 (32.2) | ||
| |||
During recent 90 days (n=86) | |||
Percentage of time CGM is active, % | 85.93±10.97 | 88.00 (81.60–95.55) | 55.30–98.30 |
Mean glucose, mg/dL | 164.23±28.38 | 162.50 (145.00–179.00) | 115.00–269.00 |
Glycemic variability, %CV | 37.30±7.94 | 37.35 (33.90–39.60) | 22.30–93.30 |
Time in range (70–180 mg/dL), % | 63.08±15.32 | 62.80 (55.00–71.90) | 19.20–96.50 |
Time above range >180 mg/dL | 33.70±16.09 | 31.45 (24.60–44.00) | 2.80–80.60 |
Time above range >250 mg/dL | 11.13±10.10 | 8.85 (4.75–14.00) | 0.20–58.80 |
Time below range <70 mg/dL | 3.22±2.96 | 2.05 (1.00–4.40) | 0.00–13.00 |
Time below range <54 mg/dL | 0.83±1.18 | 0.35 (0.10–1.00) | 0.00–6.20 |
No. of participants with time in range >70% (%) | 27 (31.4) |
Values are presented as median (interquartile range), number (%), or mean±standard deviation. Chi-square test or Fisher’s exact test was applied for categorical variables. CGM, continuous glucose monitoring; SMD, standardized mean difference; PS, propensity score; BMI, body mass index; BP, blood pressure; HDL-C, high-density lipoprotein cholesterol; LDL-C, low-density lipoprotein cholesterol; AST, aspartate aminotransferase; ALT, alanine aminotransferase; BUN, blood urea nitrogen; eGFR, estimated glomerular filtration rate. Continuous variables with normal distributions were compared using Student’s Continuous variables with non-normal distributions were compared using Mann–Whitney The Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation was used to calculate the eGFR.
CGM, continuous glucose monitoring; BMI, body mass index; BP, blood pressure; eGFR, estimated glomerular filtration rate.
Logistic regression analysis with uncontrolled glycosylated hemoglobin (>8%) as a dependent variable was performed to identify whether CGM use could influence this outcome variable. Model 1: Adjusted for age, sex, diabetes duration and body mass index; Model 2: Adjusted for model 1 plus history of cerebral infarction and acute myocardial infarction during the previous 5 years from baseline, and presence of diabetic retinopathy and end-stage renal disease at baseline; Model 3: Adjusted for model 1 plus use of insulin pump, and estimated glomerular filtration rate. CGM, continuous glucose monitoring.
CGM, continuous glucose monitoring; SD, standard deviation; IQR, interquartile range; Min, minimum; Max, maximum; CV, coefficient of variation.