Treatment responses to basal insulin glargine 300 U/ml and glargine 100 U/ml in newly defined subphenotypes of type 2 diabetes: A post hoc analysis of the EDITION 3 randomized clinical trial.

INTRODUCTION: To compare responses to basal insulin glargine 300 U/ml (IGlar-300) and 100 U/ml (IGlar-100) in newly defined subphenotypes of type 2 diabetes. METHODS: Insulin-naive participants (n = 858) from the EDITION 3 trial were assigned to subphenotypes 'Mild Age-Related Diabetes (MARD)', 'Mild Obesity Diabetes (MOD)', 'Severe Insulin Resistant Diabetes (SIRD)' and 'Severe Insulin Deficient Diabetes (SIDD)'. Key variables were analysed at baseline and 26 weeks. RESULTS: Participants were comprised of MOD 56.1% (n = 481), SIDD 22.1% (n = 190), MARD 18.2% (n = 156) and SIRD 3.0% (n = 26). After 26 weeks a similar decrease in glycated haemoglobin (HbA1c) and fasting plasma glucose (FPG) of 16-19 mmol/mol and 1.4-1.7 mmol/L, respectively, occurred in MARD and MOD with both insulins. SIDD had the most elevated HbA1c and FPG (80-83 mmol/mol/11.1-11.4 mmol/L) and reduction in both HbA1c and FPG was greater with IGlar-100 than with IGlar-300 (-18 vs. -15 mmol/mol and -1.6 vs. -1.3 mmol/L, respectively; each p = .03). In SIDD, despite receiving the highest basal insulin doses, HbA1c decline (57-60 mmol/mol/7.3-7.6%) was suboptimal at week 26. In MOD and SIDD lower incidences with IGlar-300 were found for level 1 nocturnal hypoglycaemia [odds ratio (OR) 0.59, 95% confidence intervals (CI) 0.36-0.97; OR 0.49, 95% CI 0.24-0.99]. In addition, fewer level 2 hypoglycaemia episodes occurred at any time with IGlar-300 in SIDD (OR 0.31, 95% CI 0.13-0.77). CONCLUSION: Both insulins produce comparable outcomes in type 2 diabetes subphenotypes, but in SIDD, add-on treatment to basal insulin is required to achieve glycaemic targets.

Severe hypoglycaemia in adults presenting to a hospital emergency department: Clinical characteristics, comorbidities, and mortality outcomes.

AIMS: To determine the clinical characteristics, risk factors and mortality outcomes associated with severe hypoglycaemia (SH) treated at a hospital emergency department. MATERIALS AND METHODS: Adult patients presenting with SH to the Northern General Hospital, Sheffield, UK over a 44-month period were assessed for clinical characteristics, coexisting comorbidities and mortality outcomes, including cause of death, and analysed by age of diabetes onset, below and above age 40 years. Factors that predicted mortality were determined. RESULTS: A total of 619 episodes of SH occurred in 506 individuals. Most had type 1 (T1D; n = 172 [34.0%]) or type 2 diabetes (T2D; n = 216 [42.7%]), but several attendees did not have diabetes (non-DM; n = 110 [21.7%]). Irrespective of age of diabetes onset, patients with T2D had more socioeconomic deprivation and comorbidities (P < 0.005). SH was uncommon in those with young-onset T2D, who constituted 7.2% of all episodes in diabetes. Hospital admission was high (60%-75%). The T2D cohort had the longest inpatient stay (median 5 days, vs. 2 and 3 days for the T1D and non-DM cohorts, respectively). Survival after the index SH episode was lower and mortality was higher in the non-DM (39.1%) and T2D (38.0%) cohorts than the T1D cohort (13.3%; all P < 0.05), with a median time to death of 13, 113 and 465 days, respectively. Most deaths (78%-86%) were from non-cardiovascular causes. Charlson index predicted mortality and poor survival in T1D and T2D (both P < 0.05). CONCLUSIONS: Severe hypoglycaemia requiring emergency hospital treatment is associated with non-cardiovascular deaths and exerts a disproportionately greater impact on mortality in people with T2D and those without diabetes. Multimorbidity is an important risk factor for SH and increases mortality risk.

Continuous Glucose Monitoring by Insulin-Treated Pilots Flying Commercial Aircraft Within the ARA.MED.330 Diabetes Protocol: A Preliminary Feasibility Study.

Background and Aims: A preliminary study compared the use of continuous glucose monitoring (CGM) with the use of self-monitored blood glucose (SMBG) by aircraft pilots with insulin-treated diabetes in the United Kingdom, Ireland, and Austria, certified to fly commercial aircraft within the European Aviation Safety Agency ARA.MED.330 protocol. Methods: SMBG and simultaneous interstitial glucose measurements using CGM (Dexcom G6®) were recorded during pre- and in-flight periods. Results: Eight male pilots (seven with type 1 diabetes and one with type 3c diabetes), median age of 48.5 years and median diabetes duration of 11.5 years, participated. The correlation coefficient (R) between 874 contemporaneously recorded SMBG and CGM values was 0.843, P < 0.001. The mean glucose concentration was 8.78 mmol/L (standard deviation [SD] 0.67) using SMBG compared with 8.71 mmol/L (SD 0.85) recorded using CGM. The mean absolute relative difference was 9.39% (SD 3.12). Conclusions: CGM using Dexcom G6 systems is a credible alternative to SMBG for monitoring glucose levels when insulin-treated pilots fly commercial aircraft. The study was registered with Clinical Trials.gov NCT04395378.

Response to insulin glargine 100 U/mL treatment in newly-defined subgroups of type 2 diabetes: Post hoc pooled analysis of insulin-naïve participants from nine randomised clinical trials.

AIMS: To assess insulin glargine 100 U/mL (IGlar-100) treatment outcomes according to newly-defined subgroups of type 2 diabetes mellitus (T2DM). METHODS: Insulin-naïve T2DM participants (n = 2684) from nine randomised clinical trials initiating IGlar-100 were pooled and assigned to subgroups "Mild Age-Related Diabetes (MARD)", "Mild Obesity Diabetes (MOD)", "Severe Insulin Resistant Diabetes (SIRD)", and "Severe Insulin Deficient Diabetes (SIDD)", according to age at onset of diabetes, baseline HbA1c, BMI, and fasting C-peptide using sex-specific nearest centroid approach. HbA1c, FPG, hypoglycemia, insulin dose, and body weight were analysed at baseline and 24 weeks. RESULTS: Subgroup distribution was MARD 15.3 % (n = 411), MOD 39.8 % (n = 1067), SIRD 10.5 % (n = 283), SIDD 34.4 % (n = 923). From baseline HbA1c 8.0-9.6% adjusted least square mean reductions after 24 weeks were similar between subgroups (1.4-1.5 %). SIDD was less likely to achieve HbA1c < 7.0 % (OR: 0.40 [0.29, 0.55]) than MARD. While the final IGlar-100 dose (0.36 U/kg) in MARD was lower than in other subgroups (0.46-0.50 U/kg), it had the highest hypoglycemia risk. SIRD had lowest hypoglycemia risk and SIDD exhibited greatest body weight gain. CONCLUSIONS: IGlar-100 lowered hyperglycemia similarly in all T2DM subgroups, but level of glycemic control, insulin dose, and hypoglycemia risk differed between subgroups.

Optimal Carbohydrate Dose for Treatment of Nonsevere Hypoglycemia in Insulin-Treated Patients With Diabetes: A Narrative Review.

Nonsevere hypoglycemia in people with diabetes is usually treated with rapid-acting carbohydrate, of which glucose is the most suitable form. A quantity of 15 g is recommended and repeated after 15 min if hypoglycemia persists. This recommendation has not changed for several years despite the introduction of continuous glucose monitoring, newer and more flexible insulin regimens and improved insulin delivery. The present review has examined published studies that have explored how effectively defined amounts of carbohydrate treat nonsevere hypoglycemia in adults with insulin-treated diabetes. For most nonsevere episodes of hypoglycemia, the optimal treatment is 15 to 20 g of oral glucose. However, this dose may not be appropriate with many current insulins and insulin pump therapy, where doses of glucose may have to be individualized, and based on body weight or the type of insulin delivery system. Current guidelines on hypoglycemia treatment for newer glucose-lowering therapies may require re-evaluation.

Distribution and characteristics of newly-defined subgroups of type 2 diabetes in randomised clinical trials: Post hoc cluster assignment analysis of over 12,000 study participants.

AIMS: Newly-defined subgroups of type 2 diabetes mellitus (T2DM) have been reported from real-world cohorts but not in detail from randomised clinical trials (RCTs). METHODS: T2DM participants, uncontrolled on different pre-study therapies (n = 12.738; 82 % Caucasian; 44 % with diabetes duration > 10 years) from 14 RCTs, were assigned to new subgroups according to age at onset of diabetes, HbA1c, BMI, and fasting C-peptide using the nearest centroid approach. Subgroup distribution, characteristics and influencing factors were analysed. RESULTS: In both, pooled and single RCTs, "mild-obesity related diabetes" predominated (45 %) with mean BMI of 35 kg/m2. "Severe insulin-resistant diabetes" was found least often (4.6 %) and prevalence of "mild age-related diabetes" (23.9 %) was mainly influenced by age at onset of diabetes and age cut-offs. Subgroup characteristics were widely comparable to those from real-world cohorts, but all subgroups showed higher frequencies of diabetes-related complications which were associated with longer diabetes duration. A high proportion of "severe insulin-deficient diabetes" (25.4 %) was identified with poor pre-study glycaemic control. CONCLUSIONS: Classification of RCT participants into newly-defined diabetes subgroups revealed the existence of a heterogeneous population of T2DM. For future RCTs, subgroup-based randomisation of T2DM will better define the target population and relevance of the outcomes by avoiding clinical heterogeneity.

C-peptide determination in the diagnosis of type of diabetes and its management: A clinical perspective.

Impaired beta-cell function is a recognized cornerstone of diabetes pathophysiology. Estimates of insulin secretory capacity are useful to inform clinical practice, helping to classify types of diabetes, complication risk stratification and to guide treatment decisions. Because C-peptide secretion mirrors beta-cell function, it has emerged as a valuable clinical biomarker, mainly in autoimmune diabetes and especially in adult-onset diabetes. Nonetheless, the lack of robust evidence about the clinical utility of C-peptide measurement in type 2 diabetes, where insulin resistance is a major confounder, limits its use in such cases. Furthermore, problems remain in the standardization of the assay for C-peptide, raising concerns about comparability of measurements between different laboratories. To approach the heterogeneity and complexity of diabetes, reliable, simple and inexpensive clinical markers are required that can inform clinicians about probable pathophysiology and disease progression, and so enable personalization of management and therapy. This review summarizes the current evidence base about the potential value of C-peptide in the management of the two most prevalent forms of diabetes (type 2 diabetes and autoimmune diabetes) to address how its measurement may assist daily clinical practice and to highlight current limitations and areas of uncertainties to be covered by future research.

Previously unrecognized risk factors for severe hypoglycaemia requiring emergency medical care in insulin-treated type 2 diabetes: Results from a real-world nested case-control study.

AIM: Several risk factors for severe hypoglycaemia (SH) are associated with insulin-treated diabetes. This study explored potential risk factors in adults with insulin-treated type 2 diabetes mellitus (T2DM). MATERIALS AND METHODS: In this case-control study, adults with T2DM initiating insulin were identified in the IQVIA PharMetrics® Plus database. The index date was the date of the first SH event (cases). Using incidence-density sampling, controls were selected from those who had been exposed 'at risk' of SH for the same amount of time as each case. After exact-matching on the well-established factors, previously unreported risk factors were evaluated through conditional logistic regression. RESULTS: In 3153 case-control pairs, pregnancy [odds ratios (OR) = 3.20, p = .0003], alcohol abuse (OR = 2.43, p < .0001), short-/rapid-acting insulin (OR = 2.22/1.47, p < .0001), cancer (OR = 1.87, p < .0001), dementia/Alzheimer's disease (OR = 1.73, p = .0175), peripheral vascular disease (OR = 1.59, p < .0001), antipsychotics (OR = 1.59; p = .0059), anxiolytics (OR = 1.51, p = .0012), paralysis/hemiplegia/paraplegia (OR = 1.51, p = .0416), hepatitis (OR = 1.50, p = .0303), congestive heart failure (OR = 1.47, p = .0002), adrenergic-corticosteroid combinations (OR = 1.45, p = .0165), ß-adrenoceptor agonists (OR = 1.40, p = .0225), opioids (OR = 1.38, p < .0001), corticosteroids (OR = 1.35, p = .0159), cardiac arrhythmia (OR = 1.29. p = .0065), smoking (OR = 1.28, p = .005), Charlson Comorbidity Index score 2 (OR = 1.28, p = .0026), 3 (OR = 1.41, p = .0016) or ≥4 (OR = 1.57, p = .0002), liver/gallbladder/pancreatic disease (OR = 1.26, p = .0182) and hypertension (OR = 1.19, p = .0164) were independently associated with SH. CONCLUSIONS: Although all people with insulin-treated diabetes are at risk of SH, these results have identified some previously unrecognized risk factors and sub-groups of insulin-treated adults with T2DM at greater risk. Scrutiny of current therapies and comorbidities are advised as well as additional glucose monitoring and education, when identifying and managing SH in vulnerable populations.

Out-of-Hospital Management of Diabetic Emergencies in Germany: Structural and Process Quality.

AIMS: To collect and analyse representative data of structural and process quality in the management of diabetic emergencies in Germany in 2020. METHODS: A standardised questionnaire comprising detailed items concerning clinically relevant parameters on the structural and process quality of out-of-hospital management of diabetic emergencies was sent nationwide to medical directors of emergency medical service districts (EMSDs). Results were compared with those from a similar study conducted in 2001. RESULTS: The return rate of the questionnaires represented 126 EMSDs, serving a total population of > 40.1 million. Only 4% of ambulances carried glucagon (6% in 2001). In 2020, blood glucose determination increased significantly to 71% of all emergency interventions and to 29% of suspected cardiac emergencies (24% and 15%, respectively, in 2001). In 100% of EMSDs severe hypoglycaemia (SH) was treated by paramedics by administering intravenous dextrose before the arrival of a doctor compared to 63% in 2001. The potential value of nasal glucagon was acknowledged by 43% of responders. In selected patients, treatment of SH was conducted without hospital admission in 78% of EMDs (60% in 2001). Fifty-three percent of medical directors acknowledged the need for further training in diabetic emergencies (47% in 2001). Cooperation for medical education between emergency teams and a diabetes centre was reported by 14% (41% in 2001). CONCLUSION: Structural and process quality of the management of diabetic emergencies in Germany has improved considerably since 2001. Persisting deficiencies could be improved by providing better medical equipment in ambulances and ongoing education to the entire emergency teams.

Addition of hyaluronic acid to the FIB-4 liver fibrosis score improves prediction of incident cirrhosis and hepatocellular carcinoma in type 2 diabetes: The Edinburgh Type 2 Diabetes Study.

BACKGROUND: Type 2 diabetes (T2D) is associated with increased risk of progression to cirrhosis and hepatocellular carcinoma (HCC) in people with chronic liver diseases, particularly non-alcoholic fatty liver disease (NAFLD). However, the absolute risk of progression is low. So, it is crucial to accurately identify patients who would benefit most from hepatology referral and intensified management. Current risk-stratification tools are suboptimal and perform worse in people with diabetes. AIMS: To determine whether the addition of complementary biomarker(s) to current NAFLD risk-stratification tools in people with T2D could improve the identification of people who are at increased risk of developing incident cirrhosis or HCC. METHODS: The Edinburgh Type 2 diabetes Study (ET2DS) is a cohort study of men and women with T2D (n = 1066, age 60-75 at baseline). Cases of cirrhosis and HCC were identified over 11 years of follow-up. Biomarkers were measured at baseline and year 1 and association with incident disease was assessed using logistic regression. RESULTS: Of existing risk-stratification scores tested, the Fibrosis-4 (FIB-4) index and the AST:platelet ratio index (APRI) performed best in this cohort. Addition of hyaluronic acid (cut-point ≥ 50  µ  g/L) to FIB-4 (cut-point ≥ 1.3) maintained a false negative rate of ≤25% and reduced the number of people incorrectly identified as "high risk" for incident disease by ∼50%. CONCLUSIONS: The addition of hyaluronic acid to FIB-4 reduced the proportion of people inappropriately identified as "high risk" for development of cirrhosis/HCC in a community population of otherwise asymptomatic people with T2D. These findings require a validation in independent cohorts.

100 years on: the impact of the discovery of insulin on clinical outcomes.

Throughout history, up to the early part of the 20th century, diabetes has been a devastating disorder, particularly when diagnosed in childhood when it was usually fatal. Consequently, the successful pancreatic extraction of insulin in 1921 was a miraculous, life-changing advance. In this review, the truly transformative effect that insulin has had on the lives of people with type 1 diabetes and on those with type 2 diabetes who are also dependent on insulin is described, from the time of its first successful use to the present day. We have highlighted in turn how each of the many facets of improvements over the last century, from advancements in the properties of insulin and its formulations to the evolution of different methods of delivery, have led to continued improvement in clinical outcomes, through the use of illustrative stories from history and from our own clinical experiences. This review concludes with a brief look at the current challenges and where the next century of technological innovation in insulin therapy may take us.

Effect of hypoglycaemia on measures of myocardial blood flow and myocardial injury in adults with and without type 1 diabetes: A prospective, randomised, open-label, blinded endpoint, cross-over study.

AIMS: This study examined the effect of experimentally-induced hypoglycaemia on measures of myocardial blood flow and myocardial injury in adults with, and without, type 1 diabetes. METHODS: In a prospective, randomised, open-label, blinded, endpoint cross-over study, 17 young adults with type 1 diabetes with no cardiovascular risk factors, and 10 healthy non-diabetic volunteers, underwent hyperinsulinaemic-euglycaemic (blood glucose 4.5-5.5 mmol/L) and hypoglycaemic (2.2-2.5 mmol/L) clamps. Myocardial blood flow was assessed using transthoracic echocardiography Doppler coronary flow reserve (CFR) and myocardial injury using plasma high-sensitivity cardiac troponin I (hs-cTnI) concentration. RESULTS: During hypoglycaemia, coronary flow reserve trended non-significantly lower in those with type 1 diabetes than in the non-diabetic participants (3.54 ± 0.47 vs. 3.89 ± 0.89). A generalised linear mixed-model analysis examined diabetes status and euglycaemia or hypoglycaemia as factors affecting CFR. No statistically significant difference in CFR was observed for diabetes status (p = .23) or between euglycaemia and hypoglycaemia (p = .31). No changes in hs-cTnI occurred during hypoglycaemia or in the recovery period (p = .86). CONCLUSIONS: A small change in CFR was not statistically significant in this study, implying hypoglycaemia may require more than coronary vasomotor dysfunction to cause harm. Further larger studies are required to investigate this putative problem.

Blood glucose monitoring by insulin-treated pilots of commercial and private aircraft: An analysis of out-of-range values.

AIM: To examine blood glucose measurements recorded as part of the diabetes protocol operated by the UK, Ireland and Austria, which allows commercial airline pilots with insulin-treated diabetes to fly. METHODS: An observational study was conducted in pilots with insulin-treated diabetes, granted medical certification to fly commercial or noncommercial aircraft, who recorded pre-flight and hourly in-flight blood glucose measurements. These values were correlated to a traffic light system (green 5.0 to 15.0 mmol/L; amber 4.0 to 4.9 mmol/L and 15.1 to 20.0 mmol/L; and red <4.0 mmol/L or >20.0 mmol/L) and studied for trends in glucose concentrations, time course within flight and any consequences. Pilot demographics were also analysed. RESULTS: Forty-four pilots (90%) recorded one or more blood glucose value outside the green range during the 7 years of the study. Pilot age, diabetes type and duration, and follow-up period were comparable among subgroups, and mean glycated haemoglobin did not differ before and after certification in a way which would indicate poorer glycaemic control in any subgroup. A total of 892 blood glucose values (2.31%) were outside the green range, with half reported in-flight at various time intervals. There were 48 (0.12%) low red range values recorded, 14 (0.04%) of which occurred in-flight; all but four were restored to within the green range by the time of the next measurement. Appropriate corrective action was taken for all out-of-range values, with no reports of pilot incapacitation from any cause. CONCLUSIONS: The traffic light system appears effective in identifying and reducing the frequency and severity of out-of-range values.

Non-invasive risk scores do not reliably identify future cirrhosis or hepatocellular carcinoma in Type 2 diabetes: The Edinburgh type 2 diabetes study.

BACKGROUND: The incidence of cirrhosis and hepatocellular carcinoma (HCC) is increased in Type 2 diabetes, primarily secondary to non-alcoholic fatty liver disease (NAFLD). European guidelines recommend screening for NAFLD in Type 2 diabetes. American guidelines, while not advocating a screening protocol, suggest using non-invasive markers of fibrosis for risk-stratification and guiding onward referral. AIMS: To test the ability of individual fibrosis scores and the European screening algorithm to predict 11-year incident cirrhosis/HCC in an asymptomatic community cohort of older people with Type 2 diabetes. METHODS: The Edinburgh Type 2 Diabetes Study investigated men and women with Type 2 diabetes (n = 1066, aged 60-75 at baseline). Liver markers were measured at baseline and year 1; steatosis and fibrosis markers were calculated according to independently published calculations. During 11 years of follow-up, cases of cirrhosis and HCC were identified. RESULTS: Forty-three out of 1059 participants with no baseline cirrhosis/HCC developed incident disease. All scores were significantly associated with incident liver disease by odds ratio (P < .05). The ability of the risk-stratification tools to accurately identify those who developed incident cirrhosis/HCC was poor with low-positive predictive values (5-46%) and high false-negative and -positive rates (up to 60% and 77%) respectively. When fibrosis risk scores were used in conjunction with the European algorithm, they performed modestly better than when applied in isolation. CONCLUSIONS: In a cohort with a moderately low incidence of cirrhosis/HCC, existing risk scores did not reliably identify participants at high risk. Better prediction models for cirrhosis/HCC in people with Type 2 diabetes are required.

Glucagon Administration by Nasal and Intramuscular Routes in Adults With Type 1 Diabetes During Insulin-Induced Hypoglycaemia: A Randomised, Open-Label, Crossover Study.

INTRODUCTION: Many commercially available glucagon products for treatment of severe hypoglycaemia require cumbersome reconstitution and potentially intimidating injection during an emergency. Nasal glucagon (NG) is a novel drug-device combination product consisting of a single-use dosing device that delivers glucagon dry powder through nasal administration. The present study assessed whether 3 mg NG was non-inferior to 1 mg intramuscular glucagon (IMG) in adults with type 1 diabetes. METHODS: This randomised, open-label, two-period, crossover trial was conducted at two clinical sites. Hypoglycaemia (plasma glucose [PG] target of < 3.3 mmol/l (60 mg/dl) was induced by an intravenous insulin infusion. Glucagon preparations were given by study staff. Treatment success was defined as an increase in PG to ≥ 3.9 mmol/l (70 mg/dl) or an increase of ≥ 1.1 mmol/l (20 mg/dl) from the PG nadir within 30 min of receiving glucagon. RESULTS: Of the 66 participants included in the primary efficacy analysis who received both NG and IMG, 100% achieved treatment success, thus demonstrating non-inferiority of NG to IMG. All participants achieved treatment success within 25 min with the mean time to treatment success of 11.4 min (NG) and 9.9 min (IMG). No serious adverse events occurred. Forty-eight treatment-emergent adverse events (TEAEs) occurred after NG and 51 after IMG. Most TEAEs were mild and transient. CONCLUSION: Nasal glucagon was as efficacious and well tolerated as IMG for the treatment of insulin-induced hypoglycaemia in adults and will be as useful as IMG as a rescue treatment for severe hypoglycaemia. TRIAL REGISTRATION: NCT03339453, ClinicalTrials.gov.

An Evaluation of the Safety of Pilots With Insulin-Treated Diabetes in Europe Flying Commercial and Noncommercial Aircraft.

OBJECTIVE: The risk of hypoglycemia in people with insulin-treated diabetes has debarred them from certain "safety-critical" occupations, including flying commercial aircraft. This report evaluates the effectiveness of a protocol enabling a large cohort of insulin-treated pilots to fly commercially. RESEARCH DESIGN AND METHODS: This was an observational study of pilots with insulin-treated diabetes who were granted medical certification to fly commercial and noncommercial aircraft. Clinical details, pre- and in-flight (hourly and 30 min before landing) blood glucose values were correlated against the protocol-specified ranges: green (5-15 mmol/L), amber (low, 4-4.9 mmol/L; high, 15.1-20 mmol/L), and red (low, <4 mmol/L; high, >20 mmol/L). RESULTS: A total of 49 pilots with type 1 (84%) or type 2 (16%) diabetes who had been issued class 1 or class 2 certificates were studied. Median diabetes duration was 10.9 years. Mean HbA1c was 7.2% (55.0 mmol/mol) before certification and 7.2% (55.1 mmol/mol) after certification (P = 0.97). Blood glucose values (n = 38,621) were recorded during 22,078 flying hours. Overall, 97.69% of measurements were within the green range, 1.42% within the low amber range, and 0.75% within the high amber range. Only 0.12% of readings were within the low red range and 0.02% within the high red range. Out-of-range readings declined from 5.7% in 2013 to 1.2% in 2019. No episodes of pilot incapacitation occurred, and glycemic control did not deteriorate. CONCLUSIONS: The protocol is practical to implement, and no events compromising safety were reported. This study represents what is, to our knowledge, the most extensive data set from people with insulin-treated diabetes working in a "safety-critical" occupation, which may be relevant when estimating risk in other safety-critical occupations.