Racial and Ethnic Disparities in Comorbidities in Youth With Type 2 Diabetes in the Pediatric Diabetes Consortium (PDC).

BACKGROUND: Type 2 diabetes in the U.S. is more prevalent in youth of minority racial-ethnic background, but disparities in health outcomes have not been examined in this population. RESEARCH DESIGN AND METHODS: We examined racial-ethnic differences in the initial presentation and subsequent comorbidities in 1,217 youth with type 2 diabetes (63% girls) enrolled in the Pediatric Diabetes Consortium (PDC) Registry from February 2012 to June 2018. Demographic and clinical data were collected from medical records and participant self-report. RESULTS: Overall, the mean age at presentation was 13.4 ± 2.4 years, and BMI was 35.0 ± 9.4 kg/m2. HbA1c was higher and C-peptide was lower in non-Hispanic Black (NHB) and Hispanic (H) youth compared with non-Hispanic White (NHW) youth. NHB were three times as likely to present in diabetic ketoacidosis (19%) versus NHW (6.3%) and H (7.5%), and NHB and H both had a worse HbA1c trajectory compared with NHW peers. Microalbuminuria was documented in 11%, hypertension in 34%, and dyslipidemia in 42% of Registry participants, with no significant difference among racial-ethnic groups. Nonalcoholic fatty liver disease (NAFLD) was diagnosed in 9% and 11% of H and NHW, respectively, versus 2% in NHB. CONCLUSIONS: NHB and H youth with type 2 diabetes presented with worse metabolic control and had persistently worse HbA1c trajectories compared with NHW. Comorbidities exist in a large percentage of these youth independent of race-ethnicity, except for NAFLD being less prevalent in NHB. Greater efforts are needed to mitigate racial-ethnic disparities at diagnosis and in the management of youth with type 2 diabetes.

A Pilot Study of Youth With Type 1 Diabetes Initiating Use of a Hybrid Closed-Loop System While Receiving a Behavioral Economics Intervention.

OBJECTIVE: Many youth do not use the hybrid closed-loop system for type 1 diabetes effectively. This study evaluated the impact of financial incentives for diabetes-related tasks on use of the 670G hybrid closed-loop system and on glycemia. METHODS: At auto mode initiation and for 16 weeks thereafter, participants received a flat rate for wearing and calibrating the sensor ($1/day), administering at least 3 mealtime insulin boluses per day ($1/day), and uploading ($5/week). Weekly bonuses were given for maintaining at least 70% of the time in auto mode, which were increased for persistent auto mode use from $3/week to a maximum of $13/week. If a participant failed to maintain auto mode for a week, the rewards were reset to baseline. Data from 17 participants aged 15.9 years ± 2.5 years (baseline hemoglobin A1c [HbA1c] 8.6% ± 1.1%) were collected at 6, 12, and 16 weeks. The reinforcers were withdrawn at 16 weeks, with a follow-up assessment at 24 weeks. RESULTS: With reinforcers, the participants administered an average of at least 3 mealtime insulin boluses per day and wore the sensor over 70% of the time. However, auto mode use waned. HbA1c levels decreased by 0.5% after 6 weeks, and this improvement was maintained at 12 and 16 weeks (P < .05). Upon withdrawal of reinforcers, HbA1c levels increased back to baseline at 24 weeks. CONCLUSION: Compensation for diabetes-related tasks was associated with lower HbA1c levels, consistent administration of mealtime insulin boluses, and sustained sensor use. These results support the potential of financial rewards for improving outcomes in youth with type 1 diabetes.

"I'm essentially his pancreas": Parent perceptions of diabetes burden and opportunities to reduce burden in the care of children <8 years old with type 1 diabetes.

BACKGROUND: Across all age groups, management of type 1 diabetes (T1D) places substantial responsibility and emotional burden upon families. This study explored parent perceptions of the burdens of caring for very young children with T1D. METHODS: Semi-structured qualitative interviews were conducted with parents (85% mothers) of 79 children with T1D, aged 1 to <8 years old, from four diverse pediatric diabetes clinical centers. Interviews were transcribed, coded, and analyzed using hybrid thematic analysis to derive central themes. RESULTS: Youth (77% White) had T1D for ≥6 months: age (M ± SD) 5.2 ± 1.5 years, diabetes duration 2.4 ± 1.3 years, and A1c 63 ± 10 mmol/mol (7.9 ± 0.9%); 66% used an insulin pump and 61% used CGM. Three major themes emerged related to diabetes burdens: (a) the emotional burden of diabetes on themselves and their children, (b) the burden of finding, training, and trusting effective secondary caregivers to manage the child's diabetes, and (c) suggestions for how more comprehensive, personalized diabetes education from healthcare providers for parents and secondary caregivers could help reduce parent burden and worry. CONCLUSIONS: In families with very young children with T1D, parental perceptions of the burden of managing diabetes are common and could be mitigated by tailored education programs that increase parent knowledge, bolster parents' confidence in themselves, and increase trust in their secondary caregivers to manage diabetes. Reduced parental burden and increased caregiver knowledge may positively impact child's glycemic control, as well as improve parent and child quality of life.

Glucose management for rewards: A randomized trial to improve glucose monitoring and associated self-management behaviors in adolescents with type 1 diabetes.

BACKGROUND: This randomized, controlled trial evaluated a monetary-based reinforcement intervention for increasing self-monitoring of blood glucose (SMBG) among youth with poorly controlled type 1 diabetes. METHODS: After a 2-week baseline, 60 participants were randomized to enhanced usual care (EUC) or Reinforcers. The Reinforcers group earned monetary rewards for SMBG and associated behaviors such as uploading glucose meters. Reinforcers were withdrawn at 24 weeks. A follow-up evaluation occurred at 36 weeks. RESULTS: Participants in the reinforcers group increased the proportion of days they completed ≥4 SMBG from 14.6% at baseline to 64.4%, 47.5%, and 37.8% at 6, 12, and 24 weeks, respectively. In contrast, EUC participants declined from 22.7% at baseline to 17.5%, 10.5%, and 11.1% (Ps < .01 vs EUC at all time points). Group differences were attenuated but remained significant after withdrawal of reinforcers. Effect sizes for SMBG were very large during reinforcement and large after withdrawal of reinforcers. In the reinforcers group, mean A1c dropped from 9.5% ± 1.2% at baseline to 9.0% ± 1.3% at week 6 and 9.0% ± 1.4% at week 12. For EUC, A1c was 9.2% ± 0.2% at baseline and ranged from 9.2% ± 1.5% to 9.6% ± 1.6% throughout the study (P < .05 vs EUC). Group differences in A1c were no longer significant at weeks 24 and 36. Effect sizes for A1c were small during reinforcement and also after withdrawal of reinforcement. CONCLUSIONS: Monetary-based reinforcement of adolescents with type 1 diabetes caused durable increases in SMBG. Modification of the reinforcement structure may be needed to sustain improved metabolic control in this challenging age group.

International Consensus on Risk Management of Diabetic Ketoacidosis in Patients With Type 1 Diabetes Treated With Sodium-Glucose Cotransporter (SGLT) Inhibitors.

Sodium-glucose cotransporter (SGLT) inhibitors are new oral antidiabetes medications shown to effectively reduce glycated hemoglobin (A1C) and glycemic variability, blood pressure, and body weight without intrinsic properties to cause hypoglycemia in people with type 1 diabetes. However, recent studies, particularly in individuals with type 1 diabetes, have demonstrated increases in the absolute risk of diabetic ketoacidosis (DKA). Some cases presented with near-normal blood glucose levels or mild hyperglycemia, complicating the recognition/diagnosis of DKA and potentially delaying treatment. Several SGLT inhibitors are currently under review by the U.S. Food and Drug Administration and European regulatory agencies as adjuncts to insulin therapy in people with type 1 diabetes. Strategies must be developed and disseminated to the medical community to mitigate the associated DKA risk. This Consensus Report reviews current data regarding SGLT inhibitor use and provides recommendations to enhance the safety of SGLT inhibitors in people with type 1 diabetes.

Eligibility for clinical trials is limited for youth with type 2 diabetes: Insights from the Pediatric Diabetes Consortium T2D Clinic Registry.

BACKGROUND/OBJECTIVE: Restrictive eligibility criteria have hampered enrollment into trials for new drugs for youth with type 2 diabetes (T2D). We utilized Pediatric Diabetes Consortium (PDC) T2D Registry enrollment data to estimate the percentage of patients who would be excluded from current T2D trials based on out-of-range HbA1c levels. We also examined whether well-controlled patients could be included because baseline HbA1c would rise during a 6 to 12-month study if assigned to control group. METHODS: Clinical characteristics and HbA1c levels were collected from 956 T2D patients aged 10 to <18 years upon Registry enrollment. HbA1c levels were also analyzed in 6-month intervals during the first 30 months of T2D duration. RESULTS: There was an approximately 2:1 ratio of females to males; the majority were obese and from economically disadvantaged minority families. On enrollment in the Registry, 53% of patients would be excluded from current trials because HbA1c levels were either <6.5% (<48 mmol/mol) (37%) or >10.5% (>91 mmol/mol) (16%). Furthermore, in patients with HbA1c levels <6.5% (<48 mmol/mol) and T2D duration between 6 and 30 months, mean HbA1c levels increased by 0.6% (6 mmol/mol) and 0.9% (10 mmol/mol) over the subsequent 6 and 12 months, respectively. CONCLUSIONS: Eligibility criteria for current clinical trials still exclude a large proportion of pediatric T2D patients because of HbA1c levels. Including patients with HbA1c <6.5% (<48 mmol/mol) would enhance recruitment and allow comparisons of the investigational treatment with placebo-assigned subjects in whom HbA1c levels would on average increase during the 6 to 12 months of the trial.

Frequency of Evidence-Based Screening for Retinopathy in Type 1 Diabetes.

BACKGROUND: In patients who have had type 1 diabetes for 5 years, current recommendations regarding screening for diabetic retinopathy include annual dilated retinal examinations to detect proliferative retinopathy or clinically significant macular edema, both of which require timely intervention to preserve vision. During 30 years of the Diabetes Control and Complications Trial (DCCT) and its longitudinal follow-up Epidemiology of Diabetes Interventions and Complications (EDIC) study, retinal photography was performed at intervals of 6 months to 4 years. METHODS: We used retinal photographs from the DCCT/EDIC study to develop a rational screening frequency for retinopathy. Markov modeling was used to determine the likelihood of progression to proliferative diabetic retinopathy or clinically significant macular edema in patients with various initial retinopathy levels (no retinopathy or mild, moderate, or severe nonproliferative diabetic retinopathy). The models included recognized risk factors for progression of retinopathy. RESULTS: Overall, the probability of progression to proliferative diabetic retinopathy or clinically significant macular edema was limited to approximately 5% between retinal screening examinations at 4 years among patients who had no retinopathy, 3 years among those with mild retinopathy, 6 months among those with moderate retinopathy, and 3 months among those with severe nonproliferative diabetic retinopathy. The risk of progression was also closely related to mean glycated hemoglobin levels. The risk of progression from no retinopathy to proliferative diabetic retinopathy or clinically significant macular edema was 1.0% over 5 years among patients with a glycated hemoglobin level of 6%, as compared with 4.3% over 3 years among patients with a glycated hemoglobin level of 10%. Over a 20-year period, the frequency of eye examinations was 58% lower with our practical, evidence-based schedule than with routine annual examinations, which resulted in substantial cost savings. CONCLUSIONS: Our model for establishing an individualized schedule for retinopathy screening on the basis of the patient's current state of retinopathy and glycated hemoglobin level reduced the frequency of eye examinations without delaying the diagnosis of clinically significant disease. (Funded by the National Institute of Diabetes and Digestive and Kidney Diseases and others; DCCT/EDIC ClinicalTrials.gov numbers, NCT00360893 and NCT00360815 .).

Barriers to participation in industry-sponsored clinical trials in pediatric type 2 diabetes.

BACKGROUND: The rapid emergence of type 2 diabetes (T2D) in the pediatric population has left pediatric endocrinologists with limited artillery in terms of management. While multiple medications are available for adults, Food and Drug Administration (FDA)-approved medications in children are limited to only metformin and insulin. Additional treatment options require randomized controlled trials, yet heretofore several barriers at the participant and institutional level have impeded these studies from proceeding in children and adolescents. Identification of the most challenging obstacles that pediatric endocrinologists experience in participating in industry-sponsored T2D trials may facilitate development of feasible platforms for future studies. MATERIALS AND METHODS: We conducted an anonymous online survey consisting of 31 questions that assessed potential barriers to industry-sponsored clinical trials in pediatric patients with T2D. The survey was sent to members of the Pediatric Endocrine Society (PES), and members conducted the survey between October and November of 2014. As part of the survey, respondents rated the significance of several possible barriers to participation in industry-sponsored T2D studies. RESULTS: We received a total of 207 responses from members of PES. Baseline demographics showed that 50% of represented institutions care for 50 or fewer T2D patients age 18 years and younger; 70% of institutions diagnose 20 or fewer new T2D cases per year; and 3 racial groups predominated: African American, Hispanic, and Caucasian. A total of 70% of responders have a research infrastructure to participate in clinical trials, but only half have dedicated research nurses. Protocol restrictions on participant recruitment due to current glycemic control or medication use as well as frequent visit schedules were reported to be major obstacles. In addition, the financial support provided to centers to carry out the studies is insufficient. CONCLUSIONS: Efforts must be made to ease the burden of research participation on both pediatric T2D patients as well as pediatric endocrinologists.

Hemoglobin A1c (HbA1c) changes over time among adolescent and young adult participants in the T1D exchange clinic registry.

OBJECTIVE: Hemoglobin A1c (HbA1c) levels among individuals with type 1 diabetes (T1D) influence the longitudinal risk for diabetes-related complications. Few studies have examined HbA1c trends across time in children, adolescents, and young adults with T1D. This study examines changes in glycemic control across the specific transition periods of pre-adolescence-to-adolescence and adolescence-to-young adulthood, and the demographic and clinical factors associated with these changes. RESEARCH DESIGN AND METHODS: Available HbA1c lab results for up to 10 yr were collected from medical records at 67 T1D Exchange clinics. Two retrospective cohorts were evaluated: the pre-adolescent-to-adolescent cohort consisting of 85 016 HbA1c measurements from 6574 participants collected when the participants were 8-18 yr old and the adolescent-to-young adult cohort, 2200 participants who were 16-26 yr old at the time of 17 279 HbA1c measurements. RESULTS: HbA1c in the 8-18 cohort increased over time after age 10 yr until ages 16-17; followed by a plateau. HbA1c levels in the 16-26 cohort remained steady from 16-18, and then gradually declined. For both cohorts, race/ethnicity, income, health insurance, and pump use were all significant in explaining individual variations in age-centered HbA1c (p < 0.001). For the 8-18 cohort, insulin pump use, age of onset, and health insurance were significant in predicting individual HbA1c trajectory. CONCLUSIONS: Glycemic control among patients 8-18 yr old worsens over time, through age 16. Elevated HbA1c levels observed in 18 yr-olds begin a steady improvement into early adulthood. Focused interventions to prevent deterioration in glucose control in pre-adolescence, adolescence, and early adulthood are needed.

Depressive Symptoms in Youth With Type 1 or Type 2 Diabetes: Results of the Pediatric Diabetes Consortium Screening Assessment of Depression in Diabetes Study.

OBJECTIVE: To evaluate the frequency of depressive symptoms and the diagnosis and management of depression in youth with type 1 diabetes (T1D) and type 2 diabetes (T2D) enrolled in the Pediatric Diabetes Consortium T1D and T2D registries. RESEARCH DESIGN AND METHODS: The Children's Depression Inventory (CDI) 2 Self-Report (Short) version was completed by 261 T1D and 339 T2D youth aged 10-17 years. RESULTS: Symptoms of depression were identified in 13% of T1D and 22% of T2D (P = 0.007) participants; of these, only 4% of T1D and 9% of T2D youth were treated by a therapist within the prior 12 months. Depressive symptoms were associated with lower family income (P = 0.006) and obesity (P = 0.002) in T1D but not T2D youth. CONCLUSIONS: Depressive symptoms are more frequent than diagnosed depression in youth with T1D or T2D. These results underscore the need for regular depression screening and appropriate referral for youth with diabetes.

Testing for rewards: a pilot study to improve type 1 diabetes management in adolescents.

OBJECTIVE: To evaluate the effectiveness of monetary reinforcement to increase the frequency of self-monitoring blood glucose (SMBG). RESEARCH DESIGN AND METHODS: Ten adolescents with poorly controlled diabetes enrolled in a 12-week program in which they earned monetary reinforcers based on SMBG frequency ($0.10 per test, with bonuses for ≥4 tests per day, and $251.40 maximum). RESULTS: SMBG increased from 1.8 ± 1.0 to 4.9 ± 1.0 tests per day (P < 0.001) with 90% completing four or more tests per day. Mean A1C fell from 9.3 ± 0.9% to 8.4 ± 1.5% (P = 0.05). Adolescents and parents reported high satisfaction with procedures. CONCLUSIONS: Reinforcing adolescents for SMBG may increase testing and improve A1C.

Current state of type 1 diabetes treatment in the U.S.: updated data from the T1D Exchange clinic registry.

To examine the overall state of metabolic control and current use of advanced diabetes technologies in the U.S., we report recent data collected on individuals with type 1 diabetes participating in the T1D Exchange clinic registry. Data from 16,061 participants updated between 1 September 2013 and 1 December 2014 were compared with registry enrollment data collected from 1 September 2010 to 1 August 2012. Mean hemoglobin A1c (HbA1c) was assessed by year of age from <4 to >75 years. The overall average HbA1c was 8.2% (66 mmol/mol) at enrollment and 8.4% (68 mmol/mol) at the most recent update. During childhood, mean HbA1c decreased from 8.3% (67 mmol/mol) in 2-4-year-olds to 8.1% (65 mmol/mol) at 7 years of age, followed by an increase to 9.2% (77 mmol/mol) in 19-year-olds. Subsequently, mean HbA1c values decline gradually until ∼30 years of age, plateauing at 7.5-7.8% (58-62 mmol/mol) beyond age 30 until a modest drop in HbA1c below 7.5% (58 mmol/mol) in those 65 years of age. Severe hypoglycemia (SH) and diabetic ketoacidosis (DKA) remain all too common complications of treatment, especially in older (SH) and younger patients (DKA). Insulin pump use increased slightly from enrollment (58-62%), and use of continuous glucose monitoring (CGM) did not change (7%). Although the T1D Exchange registry findings are not population based and could be biased, it is clear that there remains considerable room for improving outcomes of treatment of type 1 diabetes across all age-groups. Barriers to more effective use of current treatments need to be addressed and new therapies are needed to achieve optimal metabolic control in people with type 1 diabetes.

Longitudinal assessment of neuroanatomical and cognitive differences in young children with type 1 diabetes: association with hyperglycemia.

Significant regional differences in gray and white matter volume and subtle cognitive differences between young diabetic and nondiabetic children have been observed. Here, we assessed whether these differences change over time and the relation with dysglycemia. Children ages 4 to <10 years with (n = 144) and without (n = 72) type 1 diabetes (T1D) had high-resolution structural MRI and comprehensive neurocognitive tests at baseline and 18 months and continuous glucose monitoring and HbA1c performed quarterly for 18 months. There were no differences in cognitive and executive function scores between groups at 18 months. However, children with diabetes had slower total gray and white matter growth than control subjects. Gray matter regions (left precuneus, right temporal, frontal, and parietal lobes and right medial-frontal cortex) showed lesser growth in diabetes, as did white matter areas (splenium of the corpus callosum, bilateral superior-parietal lobe, bilateral anterior forceps, and inferior-frontal fasciculus). These changes were associated with higher cumulative hyperglycemia and glucose variability but not with hypoglycemia. Young children with T1D have significant differences in total and regional gray and white matter growth in brain regions involved in complex sensorimotor processing and cognition compared with age-matched control subjects over 18 months, suggesting that chronic hyperglycemia may be detrimental to the developing brain.

Race, socioeconomic status, and treatment center are associated with insulin pump therapy in youth in the first year following diagnosis of type 1 diabetes.

BACKGROUND: Increasing numbers of children and adolescents with type 1 diabetes (T1D) have been placed on insulin pump therapy. Nevertheless, data are limited regarding patterns of pump use during the first year of treatment and the clinical and socioeconomic factors associated with early use of pump therapy. Therefore, we sought to determine factors associated with pump therapy within the first year of diagnosis in youth enrolled in the Pediatric Diabetes Consortium (PDC) T1D New-Onset (NeOn) Study. SUBJECTS AND METHODS: The NeOn Study includes youth <19 years old at T1D diagnosis who have been followed from the time of diagnosis at seven U.S. pediatric diabetes centers. Cox regression was used to determine factors associated with transition from injection to pump therapy during the first year of T1D in 1,012 participants. RESULTS: Twenty-seven percent (n=254) of participants began pump therapy within the first year of diagnosis, ranging from 18% to 59% among the seven centers. After adjusting for center effect, factors associated with pump use in multivariate analysis included private health insurance (37% vs. 7%; P<0.001), having annual household income over $100,000 (50% vs. 15%; P<0.001), and non-Hispanic white race (36% vs. 11%; P<0.001). The hemoglobin A1c level did not appear to influence the decision to initiate pump use. CONCLUSIONS: Participants of non-Hispanic white race and higher socioeconomic status were more likely to be placed on pumps during the first year. Further investigations are needed to gain a better understanding of barriers to use of pumps in youth with T1D, especially in disadvantaged and minority families.

Health utilities for children and adults with type 1 diabetes.

OBJECTIVE: We studied health utilities in patients with type 1 diabetes to understand potential differences in health utilities as function of age, type of respondent (self report vs. proxy report), and method of assessment (direct vs. indirect). RESEARCH DESIGN AND METHODS: We elicited self-reported health utilities for adults (n=213) and children (n=238) with type 1 diabetes, and by parent proxy report (n=223) for overall quality of life [Health Utilities Index (HUI) Mark 3 and experienced time-trade-off (TTO) questions] and hypothetical complication states (TTO questions). RESULTS: Mean health utilities for overall quality of life (QOL) ranged from 0.81 to 0.91. Children had significantly higher overall QOL compared with adults (0.89 vs. 0.85, P<0.01) by HUI, but had no significant difference in QOL by TTO. There were no significant differences in QOL between child self report and parent proxy report. Utilities were higher for HUI versus TTO for parent proxy report (P<0.01) but not for adult or child self report. Utilities for hypothetical complication states were lower than for current QOL. Values were lower for stroke (0.34 to 0.53), end stage renal disease (0.47 to 0.55), and blindness (0.52 to 0.69) than for amputation (0.73 to 0.82) and angina (0.74 to 0.80). Complication utilities for parent proxy report were higher compared with adult self report for most hypothetical complication states. CONCLUSIONS: Individuals with type 1 diabetes with few complications report a relatively high QOL; however, future end stage complications are rated as having a significant impact on QOL. Differences in utilities by age, self report versus proxy report, and method raise important questions about whose utilities should be used in economic analyses.

The cost-effectiveness of continuous glucose monitoring in type 1 diabetes.

OBJECTIVE: Continuous glucose monitoring (CGM) has been found to improve glucose control in type 1 diabetic patients. We estimated the cost-effectiveness of CGM versus standard glucose monitoring in type 1 diabetes. RESEARCH DESIGN AND METHODS This societal cost-effectiveness analysis (CEA) was conducted in trial populations in which CGM has produced a significant glycemic benefit (A1C >or=7.0% in a cohort of adults aged >or=25 years and A1C <7.0% in a cohort of all ages). Trial data were integrated into a simulation model of type 1 diabetes complications. The main outcome was the cost per quality-adjusted life-year (QALY) gained. RESULTS: During the trials, CGM patients experienced an immediate quality-of-life benefit (A1C >or=7.0% cohort: 0.70 quality-adjusted life-weeks [QALWs], P = 0.49; A1C <7.0% cohort: 1.39 QALWs, P = 0.04) and improved glucose control. In the long-term, CEA for the A1C >or=7.0% cohort, CGM was projected to reduce the lifetime probability of microvascular complications; the average gain in QALYs was 0.60. The incremental cost-effectiveness ratio (ICER) was $98,679/QALY (95% CI -60,000 [fourth quadrant] to -87,000 [second quadrant]). For the A1C <7.0% cohort, the average gain in QALYs was 1.11. The ICER was $78,943/QALY (15,000 [first quadrant] to -291,000 [second quadrant]). If the benefit of CGM had been limited to the long-term effects of improved glucose control, the ICER would exceed $700,000/QALY. If test strip use had been two per day with CGM long term the ICER for CGM would improve significantly. CONCLUSIONS: Long-term projections indicate that CGM is cost-effective among type 1 diabetic patients at the $100,000/QALY threshold, although considerable uncertainty surrounds these estimates.

Continuous glucose monitoring in type 1 diabetes.

Continuous glucose monitoring is becoming increasingly more widespread for the routine care of people with type 1 diabetes mellitus and may eventually be used in closed-loop artificial beta-cell systems. The current "state of the art" of this technology, including accuracy, performance in clinical trials, limitations, and recommendations for use, is discussed for the two currently approved continuous glucose monitoring devices.