AGP Report: Continuous Glucose Monitoring
7. Diabetes Technology:
Standards of Medical Care in Diabetes—2022
Diabetes Care 2022;45(Suppl. 1):S97–S112 | https://doi.org/10.2337/dc22-S007
American Diabetes Association Professional Practice Committee*
The American Diabetes Association (ADA) “Standards of Medical Care in Dia-betes” includes the ADA’s current clinical practice recommendations and is intended to provide the components of diabetes care, general treatment goals and guidelines, and tools to evaluate quality of care. Members of the ADA Profes-sional Practice Committee, a multidisciplinary expert committee (https://doi.org/
10.2337/dc22-SPPC), are responsible for updating the Standards of Care annually, or more frequently as warranted. For a detailed description of ADA standards, statements, and reports, as well as the evidence-grading system for ADA’s clinical practice recommendations, please refer to the Standards of Care Introduction (https://doi.org/10.2337/dc22-SINT). Readers who wish to comment on the Stand-ards of Care are invited to do so at professional.diabetes.org/SOC.
Diabetes technology is the term used to describe the hardware, devices, and soft-ware that people with diabetes use to help manage their condition, from lifestyle to blood glucose levels. Historically, diabetes technology has been divided into two main categories: insulin administered by syringe, pen, or pump (also called continu-ous subcutanecontinu-ous insulin infusion [CSII]), and blood glucose as assessed by blood glucose monitoring (BGM) or continuous glucose monitoring (CGM). More recently, diabetes technology has expanded to include hybrid devices that both monitor glu-cose and deliver insulin, some automatically, as well as software that serves as a medical device, providing diabetes self-management support. Diabetes technology, when coupled with education and follow-up, can improve the lives and health of people with diabetes; however, the complexity and rapid change of the diabetes technology landscape can also be a barrier to patient and provider imple-mentation.
GENERAL DEVICE PRINCIPLES Recommendations
7.1 The type(s) and selection of devices should be individualized based on a person’s specific needs, desires, skill level, and availability of devices.
In the setting of an individual whose diabetes is partially or wholly managed by someone else (e.g., a young child or a person with cogni-tive impairment), the caregiver’s skills and desires are integral to the decision-making process.E
7.2 When prescribing a device, ensure that people with diabetes/caregivers receive initial and ongoing education and training, either in-person or remotely, and regular evaluation of technique, results, and their ability
*A complete list of members of the American Diabetes Association Professional Practice Committee can be found at https://doi.org/
10.2337/dc22-SPPC.
Suggested citation: American Diabetes Asso-ciation Professional Practice Committee. 7. Dia-betes technology: Standards of Medical Care in Diabetes—2022. Diabetes Care 2022;45 (Suppl. 1):S97–S112
© 2021 by the American Diabetes Association.
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7.DIABETESTECHNOLOGY
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to use data, including upload-ing/sharing data (if applica-ble), to adjust therapy.C 7.3 People who have been using
continuous glucose monitoring, continuous subcutaneous insu-lin infusion, and/or automated insulin delivery for diabetes management should have con-tinued access across third-party payers.E
7.4 Students must be supported at school in the use of diabe-tes technology including con-tinuous subcutaneous insulin infusion, connected insulin pens, and automated insulin delivery systems as pre-scribed by their diabetes care team.E
7.5 Initiation of continuous glu-cose monitoring, continuous subcutaneous insulin infu-sion, and/or automated insu-lin delivery early in the treatment of diabetes can be beneficial depending on a person’s/caregiver’s needs and preferences.C
Technology is rapidly changing, but there is no “one-size-fits-all” approach to technology use in people with diabe-tes. Insurance coverage can lag behind device availability, patient interest in devices and willingness to change can vary, and providers may have trouble keeping up with newly released technol-ogy. Not-for-profit websites can help providers and patients make decisions as to the initial choice of devices. Other sources, including health care providers and device manufacturers, can help people troubleshoot when difficulties arise.
Education and Training
In general, no device used in diabetes management works optimally without education, training, and follow-up.
There are multiple resources for online tutorials and training videos as well as written material on the use of devices. Patients vary in terms of com-fort level with technology, and some prefer in-person training and support.
Patients with more education regard-ing device use have better outcomes
(1); therefore, the need for additional education should be periodically assessed, particularly if outcomes are not being met.
Use in Schools
Instructions for device use should be outlined in the student’s diabetes medi-cal management plan (DMMP). A back-up plan should be included in the DMMP for potential device failure (e.g., BGM and/or injected insulin). School nurses and designees should complete training to stay up to date on diabetes technologies prescribed for use in the school setting. Updated resources to support diabetes care at school, includ-ing traininclud-ing materials and a DMMP tem-plate, can be found online at www.
diabetes.org/safeatschool.
Initiation of Device Use
Use of CGM devices should be considered from the outset of the diagnosis of diabe-tes that requires insulin management (2,3). This allows for close tracking of glu-cose levels with adjustments of insulin dosing and lifestyle modifications and removes the burden of frequent BGM. In appropriate individuals, early use of auto-mated insulin delivery (AID) systems or continuous subcutaneous insulin infusion (CSII) may be considered. Interruption of access to CGM is associated with a wors-ening of outcomes (4); therefore, it is important for individuals on CGM to have consistent access to devices.
BLOOD GLUCOSE MONITORING Recommendations
7.6 People with diabetes should be provided with blood glu-cose monitoring devices as indicated by their circumstan-ces, preferencircumstan-ces, and treat-ment. People using continuous glucose monitoring devices must have access to blood glu-cose monitoring at all times.A 7.7 People who are on insulin using blood glucose monitor-ing should be encouraged to check when appropriate based on their insulin regimen. This may include checking when fasting, prior to meals and snacks, at bedtime, prior to exercise, when low blood glucose is suspected, after
treating low blood glucose lev-els until they are normoglyce-mic, and prior to and while performing critical tasks such as driving.B
7.8 Providers should be aware of the differences in accuracy among blood glucose meters— only U.S. Food and Drug Admin-istration–approved meters with proven accuracy should be used, with unexpired strips pur-chased from a pharmacy or licensed distributor.E
7.9 Although blood glucose moni-toring in individuals on nonin-sulin therapies has not consistently shown clinically significant reductions in A1C, it may be helpful when altering diet, physical activity, and/or medications (particularly medi-cations that can cause hypogly-cemia) in conjunction with a treatment adjustment pro-gram.E
7.10 Health care providers should be aware of medications and other factors, such as high-dose vitamin C and hypoxemia, that can interfere with glucose meter accuracy and provide clinical management as indi-cated.E
Major clinical trials of insulin-treated patients have included BGM as part of multifactorial interventions to demon-strate the benefit of intensive glycemic control on diabetes complications (5).
BGM is thus an integral component of effective therapy of patients taking insu-lin. In recent years, CGM has emerged as a method for the assessment of glu-cose levels (discussed below). Gluglu-cose monitoring allows patients to evaluate their individual response to therapy and assess whether glycemic targets are being safely achieved. Integrating results into diabetes management can be a useful tool for guiding medical nutrition therapy and physical activity, preventing hypoglycemia, or adjusting medications (particularly prandial insulin doses). The patient’s specific needs and goals should dictate BGM frequency and timing or the consideration of CGM use. As recommended by the device
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manufacturers and the U.S. Food and Drug Administration (FDA), patients using CGM must have access to BGM testing for multiple reasons, including whenever there is suspicion that the CGM is inaccurate, while waiting for warm-up, for calibration (some sensors) or if a warning message appears, and in any clinical setting where glucose levels are changing rapidly (>2 mg/dL/min), which could cause a discrepancy between CGM and blood glucose.
Meter Standards
Glucose meters meeting FDA guidance for meter accuracy provide the most reliable data for diabetes management.
There are several current standards for accuracy of blood glucose monitors, but the two most used are those of the International Organization for Standardi-zation (ISO) (ISO 15197:2013) and the FDA. The current ISO and FDA standards are compared in Table 7.1. In Europe, currently marketed monitors must meet current ISO standards. In the U.S., cur-rently marketed monitors must meet the standard under which they were approved, which may not be the cur-rent standard. Moreover, the monitor-ing of current accuracy is left to the manufacturer and not routinely checked by an independent source.
Patients assume their glucose monitor is accurate because it is FDA cleared, but often that is not the case. There is sub-stantial variation in the accuracy of widely used BGM systems (6,7). The Dia-betes Technology Society Blood Glucose Monitoring System Surveillance Program provides information on the performance of devices used for BGM (www.diabe testechnology.org/surveillance/). In one
analysis, only 6 of the top 18 glucose meters met the accuracy standard (8).
There are single-meter studies in which benefits have been found with individual meter systems, but few studies have compared meters in a head-to-head man-ner. Certain meter system characteristics, such as the use of lancing devices that are less painful (9) and the ability to reap-ply blood to a strip with an insufficient initial sample, may also be beneficial to patients (10) and may make BGM less burdensome for patients to perform.
Counterfeit Strips
Patients should be advised against pur-chasing or reselling preowned or second-hand test strips, as these may give incor-rect results. Only unopened and unex-pired vials of glucose test strips should be used to ensure BGM accuracy.
Optimizing Blood Glucose Monitoring Device Use
Optimal use of BGM devices requires proper review and interpretation of data, by both the patient and the provider, to ensure that data are used in an effective and timely manner. In patients with type 1 diabetes, there is a correlation between greater BGM frequency and lower A1C (11). Among patients who check their blood glucose at least once daily, many report taking no action when results are high or low (12). Some meters now pro-vide advice to the user in real time when monitoring glucose levels (13), whereas others can be used as a part of inte-grated health platforms (14). Patients should be taught how to use BGM data to adjust food intake, exercise, or phar-macologic therapy to achieve specific goals. The ongoing need for and
frequency of BGM should be reevaluated at each routine visit to ensure its effec-tive use (12,15,16).
Patients on Intensive Insulin Regimens
BGM is especially important for insulin-treated patients to monitor for and pre-vent hypoglycemia and hyperglycemia.
Most patients using intensive insulin regi-mens (multiple daily injections [MDI] or insulin pump therapy) should be encour-aged to assess glucose levels using BGM (and/or CGM) prior to meals and snacks, at bedtime, occasionally postprandially, prior to exercise, when they suspect low blood glucose, after treating low blood glucose until they are normoglycemic, and prior to and while performing critical tasks such as driving. For many patients using BGM this requires checking up to 6–10 times daily, although individual needs may vary. A database study of almost 27,000 children and adolescents with type 1 diabetes showed that, after adjustment for multiple confounders, increased daily frequency of BGM was significantly associated with lower A1C ( 0.2% per additional check per day) and with fewer acute complications (17).
Patients Using Basal Insulin and/or Oral Agents
The evidence is insufficient regarding when to prescribe BGM and how often monitoring is needed for insulin-treated patients who do not use intensive insulin regimens, such as those with type 2 dia-betes using basal insulin with or without oral agents. However, for patients using basal insulin, assessing fasting glucose with BGM to inform dose adjustments to achieve blood glucose targets results in lower A1C (18,19).
Table 7.1—Comparison of ISO 15197:2013 and FDA blood glucose meter accuracy standards
Setting FDA (224,225) ISO 15197:2013 (226)
Home use 95% within 15% for all BG in the usable BG range† 99% within 20% for all BG in the usable BG range†
95% within 15% for BG$100 mg/dL 95% within 15 mg/dL for BG<100 mg/dL 99% in A or B region of consensus error grid‡ Hospital use 95% within 12% for BG$75 mg/dL
95% within 12 mg/dL for BG<75 mg/dL 98% within 15% for BG$75 mg/dL 98% within 15 mg/dL for BG<75 mg/dL
BG, blood glucose; FDA, U.S. Food and Drug Administration; ISO, International Organization for Standardization. To convert mg/dL to mmol/L, see endmemo.com/medical/unitconvert/Glucose.php.†The range of blood glucose values for which the meter has been proven accurate and will provide readings (other than low, high, or error).‡Values outside of the “clinically acceptable” A and B regions are considered “outlier”
readings and may be dangerous to use for therapeutic decisions (228).
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In people with type 2 diabetes not using insulin, routine glucose monitor-ing may be of limited additional clinical benefit. By itself, even when combined with education, it has showed limited improvement in outcomes (20–23).
However, for some individuals, glucose monitoring can provide insight into the impact of diet, physical activity, and medication management on glucose levels. Glucose monitoring may also be useful in assessing hypoglycemia, glu-cose levels during intercurrent illness, or discrepancies between measured A1C and glucose levels when there is concern an A1C result may not be reli-able in specific individuals. It may be useful when coupled with a treatment adjustment program. In a year-long study of insulin-naive patients with sub-optimal initial glycemic stability, a group trained in structured BGM (a paper tool was used at least quarterly to collect and interpret seven-point BGM profiles taken on 3 consecutive days) reduced their A1C by 0.3% more than the con-trol group (24). A trial of once-daily BGM that included enhanced patient feedback through messaging found no clinically or statistically significant change in A1C at 1 year (23). Meta-anal-yses have suggested that BGM can reduce A1C by 0.25–0.3% at 6 months (25–27), but the effect was attenuated at 12 months in one analysis (25).
Reductions in A1C were greater ( 0.3%) in trials where structured BGM data were used to adjust medications, but A1C was not changed significantly with-out such structured diabetes therapy adjustment (27). A key consideration is that performing BGM alone does not lower blood glucose levels. To be useful, the information must be integrated into clinical and self-management plans.
Glucose Meter Inaccuracy
Although many meters function well under a variety of circumstances, pro-viders and people with diabetes need to be aware of factors that can impair meter accuracy. A meter reading that seems discordant with clinical reality needs to be retested or tested in a labo-ratory. Providers in intensive care unit settings need to be particularly aware of the potential for abnormal meter readings, and laboratory-based values should be used if there is any doubt.
Some meters give error messages if meter readings are likely to be false (28).
Oxygen.Currently available glucose monitors utilize an enzymatic reaction linked to an electrochemical reaction, either glucose oxidase or glucose dehy-drogenase (29). Glucose oxidase moni-tors are sensitive to the oxygen available and should only be used with capillary blood in patients with normal oxygen saturation. Higher oxygen ten-sions (i.e., arterial blood or oxygen ther-apy) may result in false low glucose readings, and low oxygen tensions (i.e., high altitude, hypoxia, or venous blood readings) may lead to false high glucose readings. Glucose dehydrogenase–based monitors are not sensitive to oxygen.
Temperature.Because the reaction is sensitive to temperature, all monitors have an acceptable temperature range (29). Most will show an error if the tem-perature is unacceptable, but a few will provide a reading and a message indi-cating that the value may be incorrect.
Interfering Substances. There are a few physiologic and pharmacologic factors that interfere with glucose readings.
Most interfere only with glucose oxi-dase systems (29). They are listed in Table 7.2.
CONTINUOUS GLUCOSE MONITORING DEVICES
SeeTable 7.3 for definitions of types of CGM devices.
Recommendations
7.11 Real-time continuous glucose monitoring A or intermittently scanned continuous glucose monitoringBshould be offered for diabetes management in adults with diabetes on multiple daily injections or continuous subcutaneous insulin infusion who are capable of using devi-ces safely (either by themselves or with a caregiver). The choice of device should be made based on patient circumstances, desires, and needs.
7.12 Real-time continuous glucose monitoring Aor intermittently scanned continuous glucose monitoring C can be used
for diabetes management in adults with diabetes on basal insulin who are capa-ble of using devices safely (either by themselves or with a caregiver). The choice of device should be made based on patient circumstan-ces, desires, and needs.
7.13 Real-time continuous glucose monitoring B or intermit-tently scanned continuous glucose monitoring E should be offered for diabetes man-agement in youth with type 1 diabetes on multiple daily injections or continuous subcu-taneous insulin infusion who are capable of using the device safely (either by themselves or with a caregiver). The choice of device should be made based on patient circumstan-ces, desires, and needs.
7.14 Real-time continuous glucose monitoring or intermittently scanned continuous glucose monitoring should be offered for diabetes management in youth with type 2 diabetes on multiple daily injections or con-tinuous subcutaneous insulin infusion who are capable of using devices safely (either by themselves or with a care-giver). The choice of device should be made based on patient circumstances, desires, and needs.E
7.15 In patients on multiple daily injections and continuous sub-cutaneous insulin infusion, real-time continuous glucose moni-toring devices should be used as close to daily as possible for maximal benefit. A Intermit-tently scanned continuous glu-cose monitoring devices should be scanned frequently, at a minimum once every 8 h.A 7.16 When used as an adjunct to
pre- and postprandial blood glucose monitoring, continuous glucose monitoring can help to achieve A1C targets in diabetes and pregnancy.B
7.17 Periodic use of real-time or intermittently scanned con-tinuous glucose monitoring
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or use of professional contin-uous glucose monitoring can be helpful for diabetes man-agement in circumstances where continuous use of con-tinuous glucose monitoring is not appropriate, desired, or available.C
7.18 Skin reactions, either due to irritation or allergy, should be assessed and addressed to aid in successful use of devices.E
CGM measures interstitial glucose (which correlates well with plasma glucose, although at times it can lag if glucose levels are rising or falling rapidly).
There are two basic types of CGM devices: those that are owned by the user, unblinded, and intended for fre-quent/continuous use, including real-time CGM (rtCGM) and intermittently scanned CGM (isCGM); and profes-sional CGM devices that are owned and applied in the clinic, which provide data that are blinded or unblinded for a discrete period of time. Table 7.3 provides the definitions for the types of CGM devices. For people with type 1 diabetes using CGM, frequency of sensor use was an important predictor
of A1C lowering for all age-groups (30,31). Frequency of swiping with isCGM devices was also correlated with improved outcomes (32–35).
Some real-time systems require cali-bration by the user, which varies in frequency depending on the device.
Additionally, some CGM systems are called “adjunctive,” meaning the user should perform BGM for making treat-ment decisions. Devices that do not have this requirement, outside of certain clinical situations (seeBLOOD GLUCOSE MONI-TORINGabove), are called“nonadjunctive”
(36–38).
One specific isCGM device (FreeStyle Libre 2 [no generic form available]) and one specific rtCGM device (Dexcom G6 [no generic form available]) have been designated as integrated CGM (iCGM) devices (39). This is a higher standard, set by the FDA, so these devices can be reliably integrated with other digitally connected devices, including automated insulin-dosing systems.
Thefirst version of isCGM did not pro-vide alerts or alarms. Currently published literature does not include studies that used isCGM with alarms, which became available in June 2020 in the U.S. There-fore, the discussion that follows is based on the use of the earlier devices.
Benefits of Continuous Glucose Monitoring
Data From Randomized Controlled Trials
Multiple randomized controlled trials (RCTs) have been performed using rtCGM devices, and the results have largely been positive in terms of reducing A1C levels and/or episodes of hypoglycemia as long as participants regularly wore the devices (30,31,40–61). The initial studies were primarily done in adults and youth with type 1 diabetes on CSII and/or MDI (30,31,40–43,46–57). The primary
outcome was met and showed benefit in adults of all ages (30,40,41,46,47, 49,51,52) including seniors (48). Data in children are less consistent (30,54,55).
RCT data on rtCGM use in individuals with type 2 diabetes on MDI (58), mixed therapies (59,60), and basal insulin (61,62) have consistently shown reduc-tions in A1C but not a reduction in rates of hypoglycemia. The improvements in type 2 diabetes have largely occurred without changes in insulin doses or other diabetes medications.
RCT data for isCGM is more limited.
One study was performed in adults with type 1 diabetes and met its primary outcome of a reduction in rates of hypoglycemia (44). In adults with type 2 diabetes on insulin, two studies were done; one study did not meet its pri-mary end point of A1C reduction (63) but achieved a secondary end point of a reduction in hypoglycemia, and the other study met its primary end point of an improvement in Diabetes Treatment Satisfaction Questionnaire score as well as a secondary end point of A1C reduc-tion (64). In a study of individuals with type 1 or type 2 diabetes taking insulin, the primary outcome of a reduction in severe hypoglycemia was not met (65).
One study in youth with type 1 diabetes did not show a reduction in A1C (66);
however, the device was well received and was associated with an increased frequency of testing and improved dia-betes treatment satisfaction (66).
Observational and Real-World Studies
isCGM has been widely available in many countries for people with diabetes, and this allows for the collection of large amounts of data across groups of patients. In adults with diabetes, these data include results from observational studies, retrospective studies, and
Table 7.3—Continuous glucose monitoring devices
Type of CGM Description
rtCGM CGM systems that measure and store glucose levels continuously and without prompting isCGM with and without alarms CGM systems that measure glucose levels continuously but require scanning for storage of
glucose values
Professional CGM CGM devices that are placed on the patient in the provider’s office (or with remote instruction) and worn for a discrete period of time (generally 7–14 days). Data may be blinded or visible to the person wearing the device. The data are used to assess glycemic patterns and trends.
These devices are not fully owned by the patient—they are clinic-based devices, as opposed to the patient-owned rtCGM/isCGM devices.
CGM, continuous glucose monitoring; isCGM, intermittently scanned CGM; rtCGM, real-time CGM.
Table 7.2—Interfering substances for glucose readings
Glucose oxidase monitors Uric acid
Galactose Xylose Acetaminophen
L-DOPA Ascorbic acid
Glucose dehydrogenase monitors Icodextrin (used in peritoneal dialysis)
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analyses of registry and population data (67,68). In individuals with type 1 diabe-tes using isCGM, most (35,67,69), but not all (70), studies have shown improve-ment in A1C levels. Reductions in acute diabetes complications, such as diabetic ketoacidosis (DKA) and episodes of severe hypoglycemia, have been seen (35,70). Some retrospective/observa-tional data are available on adults with type 2 diabetes on MDI (71), basal insu-lin (72), and basal insuinsu-lin or noninsuinsu-lin therapies (73) showing improvement in A1C levels. In a retrospective study of adults with type 2 diabetes taking insu-lin, a reduction in acute diabetes-related events and all-cause hospitalizations was seen (74). Results of patient-reported outcomes varied, but where measured, patients had an increase in treatment satisfaction when comparing isCGM with BGM.
In an observational study in youth with type 1 diabetes, a slight increase in A1C and weight was seen, but the device was associated with a high rate of user satisfaction (68).
Retrospective data from rtCGM use in a Veterans Affairs population (75) with type 1 and type 2 diabetes treated with insulin show that use of real-time rtCGM significantly lowered A1C and reduced rates of emergency department visits or hospitalizations for hypoglycemia, but did not significantly lower overall rates of emergency department visits, hospitaliza-tions, or hyperglycemia.
Real-time Continuous Glucose Monitoring Compared With Intermittently Scanned Continuous Glucose Monitoring
In adults with type 1 diabetes, three RCTs have been done comparing isCGM and rtCGM (76–78). In two of the stud-ies, the primary outcome was a reduc-tion in time spent in hypoglycemia, and rtCGM showed benefit compared with isCGM (76,77). In the other study, the primary outcome was improved time in range (TIR), and rtCGM also showed benefit compared with isCGM (78). A retrospective analysis also showed improvement in TIR comparing rtCGM with isCGM (79).
Data Analysis
The abundance of data provided by CGM offers opportunities to analyze patient data more granularly than previ-ously possible, providing additional
information to aid in achieving glycemic targets. A variety of metrics have been proposed (80) and are discussed in Sec-tion 6, “Glycemic Targets” (https://doi .org/10.2337/dc22-S006). CGM is essen-tial for creating an ambulatory glucose profile and providing data on TIR, per-centage of time spent above and below range, and variability (81).
Real-time Continuous Glucose Monitoring Device Use in Pregnancy One well-designed RCT showed a reduc-tion in A1C levels in adult women with type 1 diabetes on MDI or CSII who were pregnant and using rtCGM in addition to standard care, including optimization of pre- and postprandial glucose targets (82). This study demonstrated the value of rtCGM in pregnancy complicated by type 1 diabetes by showing a mild improvement in A1C without an increase in hypoglycemia as well as reductions in large-for-gestational-age births, length of stay, and neonatal hypoglycemia (82). An observational cohort study that evalu-ated the glycemic variables reported using rtCGM found that lower mean glu-cose, lower standard deviation, and a higher percentage of time in target range were associated with lower risk of large-for-gestational-age births and other adverse neonatal outcomes (83). Use of the rtCGM-reported mean glucose is superior to use of estimated A1C, glucose management indicator, and other calcula-tions to estimate A1C given the changes to A1C that occur in pregnancy (84). Two studies employing intermittent use of rtCGM showed no difference in neonatal outcomes in women with type 1 diabetes (85) or gestational diabetes mellitus (86).
Use of Professional and Intermittent Continuous Glucose Monitoring Professional CGM devices, which pro-vide retrospective data, either blinded or unblinded, for analysis, can be used to identify patterns of hypo- and hyper-glycemia (87,88). Professional CGM can be helpful to evaluate patients when either rtCGM or isCGM is not available to the patient or the patient prefers a blinded analysis or a shorter experience with unblinded data. It can be particu-larly useful to evaluate periods of hypo-glycemia in patients on agents that can cause hypoglycemia in order to make medication dose adjustments. It can
also be useful to evaluate patients for periods of hyperglycemia.
There are some data showing benefit of intermittent use of CGM (rtCGM or isCGM) in individuals with type 2 diabe-tes on noninsulin and/or basal insulin therapies (59,89). In these RCTs, patients with type 2 diabetes not on intensive insulin regimens used CGM intermittently compared with patients randomized to BGM. Both early (59) and late improve-ments in A1C were found (59,89).
Use of professional or intermittent CGM should always be coupled with analysis and interpretation for the patient, along with education as needed to adjust medication and change life-style behaviors (90–92).
Side Effects of CGM Devices
Contact dermatitis (both irritant and allergic) has been reported with all devices that attach to the skin (93–95). In some cases this has been linked to the presence of isobornyl acrylate, which is a skin sensitizer and can cause an additional spreading allergic reaction (96–98). Patch testing can be done to identify the cause of the contact dermatitis in some cases (99). Identifying and eliminating tape allergens is important to ensure com-fortable use of devices and enhance patient adherence (100–103). In some instances, use of an implanted sensor can help avoid skin reactions in those who are sensitive to tape (104,105).
INSULIN DELIVERY Insulin Syringes and Pens
Recommendations
7.19 For people with diabetes who require insulin, insulin pens are preferred in most cases, but insulin syringes may be used for insulin delivery with consid-eration of patient/caregiver preference, insulin type and dosing regimen, cost, and self-management capabilities.C 7.20 Insulin pens or insulin injection
aids should be considered for people with dexterity issues or vision impairment to facilitate the administration of accurate insulin doses.C
7.21 Connected insulin pens can be helpful for diabetes
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