Thanks to significant improvements in the precision, accuracy, and usability of continuous glucose monitoring (CGM), its relevance in both ambulatory diabetes care and clinical research is increasing. In this study, we address the latter perspective and derive provisional reporting recommendations. CGM systems have been available since around the year 2000 and used primarily in people with type 1 diabetes. In contrast to self-measured glucose, CGM can provide continuous real-time measurement of glucose levels, alerts for hypoglycemia and hyperglycemia, and a detailed assessment of glycemic variability. Through a broad spectrum of derived glucose data, CGM should be a useful tool for clinical evaluation of new glucose-lowering medications and strategies. It is the only technology that can measure hyperglycemic and hypoglycemic exposure in ambulatory care, or provide data for comprehensive assessment of glucose variability. Other advantages of current CGM systems include the opportunity for improved self-management of glycemic control, with particular relevance to those at higher risk of or from hypoglycemia. We therefore summarize the current status and limitations of CGM from the perspective of clinical trials and derive suggested recommendations for how these should facilitate optimal CGM use and reporting of data in clinical research.
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References
1.
RodbardD: Continuous glucose monitoring: a review of successes, challenges, and opportunities. Diabetes Technol Ther, 2016; 18 (Suppl. 2):S3–S13.
2.
GrossTM, BodeBW, EinhornD, et al.: Performance evaluation of the MiniMed continuous glucose monitoring system during patient home use. Diabetes Technol Ther, 2000; 2:49–56.
3.
BaileyT, BodeBW, ChristiansenMP, et al.: The performance and usability of a factory-calibrated flash glucose monitoring system. Diabetes Technol Ther, 2015; 17:787–794.
4.
DamianoER, McKeonK, El-KhatibFH, et al.: A comparative effectiveness analysis of three continuous glucose monitors: the navigator, G4 platinum, and enlite. J Diabetes Sci Technol, 2014; 8:699–708.
5.
LaffelL: Improved accuracy of continuous glucose monitoring systems in pediatric patients with diabetes mellitus: results from two studies. Diabetes Technol Ther, 2016; 18 (Suppl. 2):S23–S33.
6.
NakamuraK, BaloA: The accuracy and efficacy of the Dexcom G4 platinum continuous glucose monitoring system. J Diabetes Sci Technol, 2015; 9:1021–1026.
7.
PleusS, SchoemakerM, MorgensternK, et al.: Rate-of-change dependence of the performance of two CGM systems during induced glucose swings. J Diabetes Sci Technol, 2015; 9:801–807.
8.
KovatchevBP: Hypoglycemia reduction and accuracy of continuous glucose monitoring. Diabetes Technol Ther, 2015; 17:530–533.
9.
KovatchevBP, PatekSD, OrtizEA, BretonMD: Assessing sensor accuracy for non-adjunct use of continuous glucose monitoring. Diabetes Technol Ther, 2015; 17:177–186.
10.
PickupJC, FreemanSC, SuttonAJ: Glycaemic control in type 1 diabetes during real time continuous glucose monitoring compared with self monitoring of blood glucose: meta-analysis of randomised controlled trials using individual patient data. BMJ, 2011; 343:d3805.
Approval Order: FreeStyle Libre Pro Flash Glucose Monitoring System. [press release]. 2016. Department of Health and Human Services.
13.
BolinderJ, AntunaR, Geelhoed-DuijvestijnP, et al.: Novel glucose-sensing technology and hypoglycaemia in type 1 diabetes: a multicentre, non-masked, randomised controlled trial. Lancet, 2016; 388:2254–2263.
14.
HeinemannL, FreckmannG: CGM versus FGM; or, continuous glucose monitoring is not flash glucose monitoring. J Diabetes Sci Technol, 2015; 9:947–950.
15.
De VriesJH: Accuracy and longevity of an implantable continuous glucose sensor in the precise study: a prospective multi-center pivotal trial; 90 day interim results. 2015; http://www.senseonics.com/∼/media/Files/S/Senseonics-IR/documents/publications/attd2016-90dayfullstudy-v7-2-411.pdf (accessed 28February2017).
TamborlaneWV, BeckRW, BodeBW, et al.: Continuous glucose monitoring and intensive treatment of type 1 diabetes. N Engl J Med, 2008; 359:1464–1476.
18.
American Diabetes Association: Standards of medical care in diabetes—2016. Diabetes Care, 2016; 39 (Suppl. 1):S1–S112.
19.
BaroneMT, WeyD, SchorrF, et al.: Sleep and glycemic control in type 1 diabetes. Arch Endocrinol Metab, 2015; 59:71–78.
20.
BattelinoT, PhillipM, BratinaN, et al.: Effect of continuous glucose monitoring on hypoglycemia in type 1 diabetes. Diabetes Care, 2011; 34:795–800.
21.
BeckRW, HirschIB, LaffelL, et al.: The effect of continuous glucose monitoring in well-controlled type 1 diabetes. Diabetes Care, 2009; 32:1378–1383.
22.
ChoudharyP, OlsenBS, CongetI, et al.: Hypoglycemia prevention and user acceptance of an insulin pump system with predictive low glucose management. Diabetes Technol Ther, 2016; 18:288–291.
23.
DeissD, BolinderJ, RivelineJP, et al.: Improved glycemic control in poorly controlled patients with type 1 diabetes using real-time continuous glucose monitoring. Diabetes Care, 2006; 29:2730–2732.
24.
HermanidesJ, NorgaardK, BruttomessoD, et al.: Sensor-augmented pump therapy lowers HbA(1c) in suboptimally controlled Type 1 diabetes; a randomized controlled trial. Diabet Med, 2011; 28:1158–1167.
25.
HirschIB, AbelsethJ, BodeBW, et al.: Sensor-augmented insulin pump therapy: results of the first randomized treat-to-target study. Diabetes Technol Ther, 2008; 10:377–383.
26.
LindM, PolonskyW, HirschIB, et al.: Continuous glucose monitoring vs conventional therapy for glycemic control in adults with type 1 diabetes treated with multiple daily insulin injections: the GOLD randomized clinical trial. JAMA, 2017; 317:379–387.
27.
BeckRW, RiddlesworthT, RuedyK, et al.: Effect of continuous glucose monitoring on glycemic control in adults with type 1 diabetes using insulin injections: the DIAMOND randomized clinical trial. JAMA, 2017; 317:371–378.
28.
O'ConnellMA, DonathS, O'NealDN, et al.: Glycaemic impact of patient-led use of sensor-guided pump therapy in type 1 diabetes: a randomised controlled trial. Diabetologia, 2009; 52:1250–1257.
29.
RaccahD, SulmontV, ReznikY, et al.: Incremental value of continuous glucose monitoring when starting pump therapy in patients with poorly controlled type 1 diabetes: the RealTrend study. Diabetes Care, 2009; 32:2245–2250.
30.
BarnardK, CrabtreeV, AdolfssonP, et al.: Impact of type 1 diabetes technology on family members/significant others of people with diabetes. J Diabetes Sci Technol, 2016; 10:824–830.
31.
KubiakT, MannCG, BarnardKC, HeinemannL: Psychosocial aspects of continuous glucose monitoring: connecting to the patients' experience. J Diabetes Sci Technol, 2016; 10:859–863.
32.
VigerskyR, ShrivastavM: Role of continuous glucose monitoring for type 2 in diabetes management and research. J Diabetes Complications, 2017; 31:280–287.
BeckRW, CalhounP, KollmanC: Use of continuous glucose monitoring as an outcome measure in clinical trials. Diabetes Technol Ther, 2012; 14:877–882.
35.
BaekJH, JinSM, KakuK, et al.: Efficacy of mitiglinide and sitagliptin, alone or in combination, on postprandial excursion and glycemic variability assessed by continuous glucose monitoring: a post hoc analysis with single-day treatment. Expert Opin Pharmacother, 2015; 16:1127–1136.
36.
BergenstalRM, BaileyTS, RodbardD, et al.: Comparison of insulin glargine 300 Units/mL and 100 Units/mL in adults with type 1 diabetes: continuous glucose monitoring profiles and variability using morning or evening injections. Diabetes Care, 2017; 40:554–560.
37.
MaZ, ChenR, LiuY, et al.: Effect of liraglutide vs. NPH in combination with metformin on blood glucose fluctuations assessed using continuous glucose monitoring in patients with newly diagnosed type 2 diabetes. Int J Clin Pharmacol Ther, 2015; 53:933–939.
38.
HolstJJ, BuseJB, RodbardHW, et al.: IDegLira improves both fasting and postprandial glucose control as demonstrated using continuous glucose monitoring and a standardized meal test. J Diabetes Sci Technol, 2015; 10:389–397.
39.
WangJS, LinSD, LeeWJ, et al.: Effects of acarbose versus glibenclamide on glycemic excursion and oxidative stress in type 2 diabetic patients inadequately controlled by metformin: a 24-week, randomized, open-label, parallel-group comparison. Clin Ther, 2011; 33:1932–1942.
40.
BergenstalRM, RosenstockJ, BastyrEJ3rd, et al.: Lower glucose variability and hypoglycemia measured by continuous glucose monitoring with novel long-acting insulin LY2605541 versus insulin glargine. Diabetes Care, 2014; 37:659–665.
41.
KingAB, ClarkD: Omitting late-night eating may cause hypoglycemia in “well controlled” Basal insulin-treated type 2 diabetes. Endocr Pract, 2015; 21:280–285.
42.
WadaN, MoriK, NakagawaC, et al.: Improved glycemic control with teneligliptin in patients with type 2 diabetes mellitus on hemodialysis: evaluation by continuous glucose monitoring. J Diabetes Complications, 2015; 29:1310–1313.
43.
MaahsDM, BuckinghamBA, CastleJR, et al.: Outcome measures for artificial pancreas clinical trials: a consensus report. Diabetes Care, 2016; 39:1175–1179.
MazzeRS, StrockE, WesleyD, et al.: Characterizing glucose exposure for individuals with normal glucose tolerance using continuous glucose monitoring and ambulatory glucose profile analysis. Diabetes Technol Ther, 2008; 10:149–159.
46.
AndoK, NishimuraR, TsujinoD, et al.: 24-hour glycemic variations in drug-naive patients with type 2 diabetes: a continuous glucose monitoring (CGM)-based study. PLoS One, 2013; 8:e71102.
47.
DerosaG, FranzettiI, QuerciF, et al.: Effect of acarbose on glycemic variability in patients with poorly controlled type 2 diabetes mellitus receiving stable background therapy: a placebo-controlled trial. Pharmacotherapy, 2015; 35:983–990.
48.
KusunokiY, KatsunoT, NakaeR, et al.: Insulin resistance and beta-cell function influence postprandial blood glucose levels in Japanese patients with gestational diabetes mellitus. Gynecol Endocrinol, 2015; 31:929–933.
49.
NielsenJB, AbildCB, PedersenAM, et al.: Continuous glucose monitoring after gastric bypass to evaluate the glucose variability after a low-carbohydrate diet and to determine hypoglycemia. Obes Surg, 2016; 26:2111–2118.
50.
ZhouJ, LiH, RanX, et al.: Reference values for continuous glucose monitoring in Chinese subjects. Diabetes Care, 2009; 32:1188–1193.
51.
BergenstalRM, AhmannAJ, BaileyT, et al.: Recommendations for standardizing glucose reporting and analysis to optimize clinical decision making in diabetes: the Ambulatory Glucose Profile (AGP). Diabetes Technol Ther, 2013; 15:198–211.
52.
FonsecaVA, GrunbergerG, AnhaltH, et al.: Continuous glucose monitoring: a consensus conference of the American Association of Clinical Endocrinologists and American College of Endocrinology. Endocr Pract, 2016; 22:1008–1021.
53.
RodbardD: Glycemic variability: measurement and utility in clinical medicine and research—one viewpoint. Diabetes Technol Ther, 2011; 13:1077–1080.
54.
MazzeRS, LucidoD, LangerO, et al.: Ambulatory glucose profile: representation of verified self-monitored blood glucose data. Diabetes Care, 1987; 10:111–117.
55.
ChamberlainJ, DopitaD, GilgenE: Persistence of continuous glucose monitoring use in a community setting 1 year after purchase. Clin Diabetes, 2013; 31:106–109.
56.
SchnellO, BarnardK, BergenstalR, et al.: Clinical utility of SMBG: recommendations on the use and reporting of SMBG in clinical research. Diabetes Care, 2015; 38:1627–1633.
57.
Workgroup on Hypoglycemia (ADA): Defining and reporting hypoglycemia in diabetes. Diabetes Care, 2005; 28:1245–1249.
58.
HovorkaR, KumareswaranK, HarrisJ, et al.: Overnight closed loop insulin delivery (artificial pancreas) in adults with type 1 diabetes: crossover randomised controlled studies. BMJ, 2011; 342:d1855.
