A scalable application of Artificial Intelligence-Driven Insulin Titration Program to transform Type 2 Diabetes Management

BACKGROUND

Despite new pharmacotherapy, most patients with long-term Type 2 Diabetes are still hyperglycemic. This could have been solved by insulin with its unlimited potential efficacy, but its dynamic physiology demands frequent titrations which are overdemanding. This report provides a real-life account for a scalable transformation of diabetes care in a community-based endocrinology center by harnessing AI-based autonomous insulin titration.

METHODS

The center embedded the d-Nav® technology and its dedicated clinical support. Reported outcomes include treatment efficacy/safety in the first 600 patients and use of cardiorenal-risk reduction pharmacotherapy.

FINDINGS

Patients used d-Nav for 8.2±3.0 months with 82% retention. Age was 67.1±11.5 years and duration of diabetes was 19.8±11.0 years. During the last 3 years before d-Nav, HbA1c had been overall higher than 8% and at the beginning of the program it was as high as 8.6%±2.1% with 29.3% of the patients with HbA1c>9%. With d-Nav, HbA1c decreased to 7.3%±1.2% with 5.7% of patients with HbA1c>9%. During the first 3 months, d-Nav reduced total daily dose of insulin in 1 of every 5 patients due to relatively low glucose levels to minimize the risk of hypoglycemia. GLP-1 or dual GLP-1 and GIP receptor agonists were prescribed in about a half of the patients and SGLT2 inhibitor in a third. The frequency of hypoglycemia (<54mg/dl) was 0.4±0.6/month and severe hypoglycemia 1.7/100-patient-years.

INTERPRETATION

The use of d-Nav allowed for improvement in overall diabetes management with appropriate use of both insulin and non-insulin pharmacologic agents in a scalable way.

Challenging the 50-50 rule for the basal-bolus insulin ratio in patients with type 2 diabetes who maintain stable glycaemic control

BACKGROUND

For patients using basal-bolus insulin therapy, it is widespread clinical practice to aim for a 50-50 ratio between basal and total daily bolus. However, this practice was based on a small study of individuals without diabetes. To assess the rule in real-world practice, we retrospectively analyzed patients on basal-bolus therapy that was adjusted at least weekly by an artificial intelligence-driven titration within the d-Nav® Insulin Management Technology.

MATERIALS AND METHODS

We obtained de-identified data from the Diabetes Centre of Ulster Hospital for patients with four inclusion criteria: type 2 Diabetes (T2D), on d-Nav >6 months, on basal-bolus insulin therapy >80% of the time (based on insulin analogs), and no gap in data >3 months.

RESULTS

We assembled a cohort of 306 patients, followed by the d-Nav service for 3.4 ± 1.8 years (mean ± SD), corresponding to about 180 autonomous insulin dose titrations and about 5000 autonomous individual dose recommendations per patient. After an initial run-in period, mean glycated hemoglobin (HbA1c) values in the cohort were maintained close to 7%. Surprisingly, in just over three-quarters of the cohort, the average basal insulin fraction was <50%; in half of the cohort average basal insulin fraction <41.2%; and in one-quarter the basal insulin fraction was <33.6%. Further, the basal insulin fraction did not remain static over time. In half of the patients, the basal insulin fraction varied by ≥1.9×; and, in 25% of the patients, ≥2.5×.

CONCLUSION

Our data show that a 50-50 ratio of basal-to-bolus insulin does not generally apply to patients with T2D who successfully maintain stable glycemia. Therefore, the 50-50 ratio should not serve as an ongoing treatment guide. Moreover, our results emphasize the importance of at least weekly insulin titrations.

For debate; pharmacological priorities in advanced type 2 diabetes

A multitude of therapeutic agents have been available to treat patients with Type 2 diabetes. Unfortunately, many patients with advanced Type 2 diabetes continue to suffer from complications and premature death. To date, all available guidelines emphasize a variety of therapeutic aspects, goals, and pharmacological combinations, without directing the clinician as to which is a higher priority. The following review attempts to clarify which therapeutic option is more important for prognosis in patients with advanced type 2 diabetes. The body of evidence presented, reveal that the most important marker for prognosis is HbA1c. Each 1% incrementally higher HbA1c than ~7% is associated with 15%-45% reduced survival rates. Therefore, any agents that can achieve the time-sensitive objective of lowering HbA1c levels should be used.

Automated insulin dosing guidance to optimise insulin management in patients with type 2 diabetes: a multicentre, randomised controlled trial

BACKGROUND

Insulin therapy is most effective if dosage titrations are done regularly and frequently, which is seldom practical for most clinicians, resulting in an insulin titration gap. The d-Nav Insulin Guidance System (Hygieia, Livonia, MI, USA) is a handheld device that is used to measure glucose, determine glucose patterns, and automatically determine the appropriate next insulin dose. We aimed to determine whether the combination of the d-Nav device and health-care professional support is superior to health-care professional support alone.

METHODS

In this multicentre, randomised, controlled study, we recruited patients from three diabetes centres in the USA (in Detroit MI; Minneapolis, MN; and Des Moines IA). Patients were eligible if they were aged 21-70 years, diagnosed with type 2 diabetes with a glycated haemoglobin (HbA1c) concentration of 7·5% or higher (≥58 mmol/mol) and 11% or lower (≤97 mmol/mol), and had been using the same insulin regimen for the previous 3 months. Exclusion criteria included body-mass index of 45 kg/m2 or higher; severe cardiac, hepatic, or renal impairment; and more than two severe hypoglycaemic events in the past year. Eligible participants were randomly assigned (1:1), with randomisation blocked within each site, to either d-Nav and health-care professional support (intervention group) or health-care professional support alone (control group). Both groups were contacted seven times (three face-to-face and four phone visits) during 6 months of follow-up. The primary objective was to compare average change in HbA1c from baseline to 6 months. Safety was assessed by the frequency of hypoglycaemic events. The primary objective and safety were assessed in the intention-to-treat population. We used Student's t test to assess the primary outcome for statistical significance. This study was registered with ClinicalTrials.gov, number NCT02424500.

FINDINGS

Between Feb 2, 2015, and March 17, 2017, 236 patients were screened for eligibility, of whom 181 (77%) were enrolled and randomly assigned to the intervention (n=93) and control (n=88) groups. At baseline, mean HbA1c was 8·7% (SD 0·8; 72 mmol/mol [SD 8·8]) in the intervention group and 8·5% (SD 0·8; 69 mmol/mol [SD 8·8]) in the control group. The mean decrease in HbA1c from baseline to 6 months was 1·0% (SD 1·0; 11 mmol/mol [SD 11]) in the intervention group, and 0·3% (SD 0·9; 3·3 mmol/mol [9·9]) in the control group (p<0·0001). The frequency of hypoglycaemic events per month was similar between the groups (0·29 events per month [SD 0·48] in the intervention group vs 0·29 [SD 1·12] in the control group; p=0·96).

INTERPRETATION

The combination of automated insulin titration guidance with support from health-care professionals offers superior glycaemic control compared with support from health-care professionals alone. Such a solution facilitated safe and effective insulin titration in a large group of patients with type 2 diabetes, and now needs to be evaluated across large health-care systems to confirm these findings and study cost-effectiveness.

FUNDING

US National Institutes of Health, National Institute of Digestive and Kidney Diseases.

Temporary Reductions in Insulin Requirements Are Associated with Hypoglycemia in Type 2 Diabetes

Background: In patients with type 2 diabetes, insulin therapy necessitates regular and frequent dosage titration to overcome variations in insulin requirements. The goal of this study was to evaluate changes in insulin requirements, using data from a technology-based insulin-titration service. Methods: To keep glycemia stable, the service adjusts and records insulin dosage at least weekly. Therefore, insulin dosage closely tracks insulin requirement. Events of considerable and persistent decrease in insulin requirements were identified by reductions in total daily dose (TDD) of insulin ≥25%. Periods ended when a persistent increase in TDD of insulin has started. The average frequency of hypoglycemia was expressed as any glucose reading <54 mg/dL (both inside or outside periods of decrease in insulin dosage) divided by the total number of months for each patient. Results: Patients (n = 246) were followed for 2.8 ± 0.9 years. Reductions of TDD of insulin were experienced by 70.3% of the patients, occurred 0.8 ± 0.5 times per year, lasted 10.0 ± 7.7 weeks, and insulin requirements declined by 39.9% ± 12.6%. The frequency of hypoglycemia (<54 mg/dL) was low, at 0.5 ± 0.6 per month, and the difference in frequencies in biphasic/premixed and basal-bolus insulin regimens was not statistically significant. Hypoglycemia was 6.5 times more prevalent during reductions in TDD of insulin. Conclusions: Sizeable changes in insulin requirements occur over time, which demand persistent and frequent titration to preserve treatment safety.

Insulin therapy, weight gain and prognosis

Insulin therapy is mainly used by people with type 2 diabetes who have failed other therapies and have become insulin-deficient. This group represents about a quarter of all people with type 2 diabetes. Almost all those with type 2 diabetes who start insulin therapy or intensify it gain weight, which may potentially diminish the prognostic advantage of improved glycaemia. To date, all available guidelines emphasize both the attainment of glycated haemoglobin (HbA1c) goals and weight control, without directing the clinician as to which element is of a higher priority. The following review attempts to clarify the issue using the available literature. The body of evidence presented in this review indicates that glycaemic management with exogenous insulin replacement is of a much higher priority than weight gain. Lower weight or weight loss do not show prognostic benefit in advanced stages of diabetes; therefore, weight gain should not discourage providers from achieving and maintaining HbA1c goals with insulin therapy, regardless of insulin dosage or other medications.

THE EFFICACY AND SAFETY OF CO-ADMINISTRATION OF SITAGLIPTIN WITH METFORMIN IN PATIENTS WITH TYPE 2 DIABETES AT HOSPITAL DISCHARGE

OBJECTIVE

Few randomized controlled trials have focused on the optimal management of patients with type 2 diabetes (T2D) during the transition from the inpatient to outpatient setting. This multicenter open-label study explored a discharge strategy based on admission hemoglobin A1c (HbA1c) to guide therapy in general medicine and surgery patients with T2D.

METHODS

Patients with HbA1c ≤7% (53 mmol/mol) were discharged on sitagliptin and metformin; patients with HbA1c between 7 and 9% (53-75 mmol/mol) and those >9% (75 mmol/mol) were discharged on sitagliptinmetformin with glargine U-100 at 50% or 80% of the hospital daily dose. The primary outcome was change in HbA1c at 3 and 6 months after discharge.

RESULTS

Mean HbA1c on admission for the entire cohort (N = 253) was 8.70 ± 2.3% and decreased to 7.30 ± 1.5% and 7.30 ± 1.7% at 3 and 6 months ( P<.001). Patients with HbA1c <7% went from 6.3 ± 0.5% to 6.3 ± 0.80% and 6.2 ± 1.0% at 3 and 6 months. Patients with HbA1c between 7 and 9% had a reduction from 8.0 ± 0.6% to 7.3 ± 1.1% and 7.3 ± 1.3%, and those with HbA1c >9% from 11.3 ± 1.7% to 8.0 ± 1.8% and 8.0 ± 2.0% at 3 and 6 months after discharge (both P<.001). Clinically significant hypoglycemia (<54 mg/dL) was observed in 4%, 4%, and 7% among patients with a HbA1c <7%, 7 to 9%, and >9%, while a glucose <40 mg/dL was reported in <1% in all groups.

CONCLUSION

The proposed HbA1c-based hospital discharge algorithm using a combination of sitagliptin-metformin was safe and significantly improved glycemic control after hospital discharge in general medicine and surgery patients with T2D.

ABBREVIATIONS

BG = blood glucose; DPP-4 = dipeptidyl peptidase-4; eGFR = estimated glomerular filtration rate; HbA1c = hemoglobin A1c; T2D = type 2 diabetes.

Insulin therapy for type 2 diabetes - are we there yet? The d-Nav® story

Insulin replacement therapy is mostly used by patients with type 2 diabetes who become insulin deficient and have failed other therapeutic options. They comprise about a quarter of those with diabetes, endures the majority of the complications and consumes the majority of the resources. Adequate insulin replacement therapy can prevent complications and reduce expenses, as long as therapy goals are achieved and maintained. Sadly, these therapy goals are seldom achieved and outcomes have not improved for decades despite advances in pharmacotherapy and technology.

There is a growing recognition that the low success rate of insulin therapy results from intra-individual and inter-individual variations in insulin requirements. Total insulin requirements per day vary considerably between patients and constantly change without achieving a steady state. Thus, the key element in effective insulin therapy is unremitting and frequent dosage adjustments that can overcome those dynamics. In practice, insulin adjustments are done sporadically during outpatient clinic. Due to time constraints, providers are not able to deliver appropriate insulin dosage optimization.

The d-Nav® Insulin Guidance Service has been developed to provide appropriate insulinization in insulin users without increasing the burden on healthcare systems. It relies on dedicated clinicians and a spectrum of technological solutions. Patients are provided with a handheld device called d-Nav® which advises them what dose of insulin to administer during each injection and automatically adjust insulin dosage when needed. The d-Nav care specialists periodically follow-up with users through telephone calls and in-person consultations to bestow user confidence, correct usage errors, triage, and identify uncharacteristic clinical courses.

The following review provide details about the service and its clinical outcomes.

Type 2 diabetes specialty clinic model for the accountable care organization era

AIMS

A third of the patients with Type 2 diabetes have an advance disease that requires complex pharmacotherapies and advanced expertise, dependent on multiple clinical interactions. Unfortunately, limited providers availability enables only sporadic interactions. Additionally, the expanding Accountable Care Organization (ACO) concept enhances providers' compensation when clinical performance is improving while limiting face-to-face clinic visits.

METHODS

We developed an advanced type 2 specialty clinic model, geared toward frequent remote clinical interventions while limiting face-to-face clinic visits. The model was tested in a 1-year, prospective, randomized controlled clinical trial. N=60, patients were randomized 1:1, to the experimental or standard endocrinology clinics.

RESULTS

Average A1c in the experimental arm decreased from 9.6±0.9% to 7.9±1.3%(p<0.0001). Whereas in the control it decreased from 8.9±0.8% to 8.6±1.9%(non-significant). More patients were treated with statins in the experimental arm compared to the control (93.3% vs. 66.7%; p=0.01). Face-to-face clinic visits occurred 1.5±0.7 times per year in the experimental arm compared to 3.6±4.0 in the control (p<0.0001).

CONCLUSIONS

We believe that the presented model for a modified type 2 diabetes specialty clinic may enhance providers accessibility and patients' outcomes while improving reimbursement in the ACO model.

Efficacy of sitagliptin for the hospital management of general medicine and surgery patients with type 2 diabetes (Sita-Hospital): a multicentre, prospective, open-label, non-inferiority randomised trial

BACKGROUND

The role of incretin-based drugs in the treatment of patients with type 2 diabetes admitted to hospital has not been extensively assessed. In this study, we compared the safety and efficacy of a dipeptidyl peptidase-4 inhibitor (sitagliptin) plus basal insulin with a basal-bolus insulin regimen for the management of patients with type 2 diabetes in general medicine and surgery in hospitals.

METHODS

We did a multicentre, prospective, open-label, non-inferiority randomised clinical trial (Sita-Hospital) in five hospitals in the USA, enrolling patients aged 18-80 years with type 2 diabetes and a random blood glucose concentration of 7·8-22·2 mmol/L who were being treated with diet or oral antidiabetic drugs or had a total daily insulin dose of 0·6 units per kg or less, admitted to general medicine and surgery services. We randomly assigned patients (1:1) to receive either sitagliptin plus basal glargine once daily (the sitagliptin-basal group) or a basal-bolus regimen with glargine once daily and rapid-acting insulin lispro or aspart before meals (the basal-bolus group) during the hospital stay. All other antidiabetic drugs were discontinued on admission. The randomisation was achieved by computer-generated tables with block stratification according to randomisation blood glucose concentrations (ie, higher or lower than 11·1 mmol/L). The primary endpoint of the trial was non-inferiority in mean differences between groups in their daily blood glucose concentrations during the first 10 days of therapy (point-of-care measurements; non-inferiority was deemed a difference <1 mmol/L). The safety endpoints included hypoglycaemia and uncontrolled hyperglycaemia leading to treatment failure. All participants who received at least one dose of study drug were included in the analysis. This study is registered with ClinicalTrials.gov, number NCT01845831.

FINDINGS

Between Aug 23, 2013, and July 27, 2015, we recruited 279 patients, and randomly assigned 277 to treatment; 138 to sitagliptin-basal and 139 to basal-bolus. The length of stay in hospital was similar for both groups (median 4 days [IQR 3-8] vs 4 [3-8] days, p=0·54). The mean daily blood glucose concentration in the sitagliptin-basal group (9·5 mmol/L [SD 2·7]) was not inferior to that in the basal-bolus group 9·4 mmol/L [2·7]) with a mean blood glucose difference of 0·1 mmol/L (95% CI -0·6 to 0·7). No deaths occurred in this trial. Treatment failure occurred in 22 patients (16%) in the sitagliptin-basal group versus 26 (19%) in the basal-bolus group (p=0·54). Hypoglycaemia occurred in 13 patients (9%) in the sitagliptin-basal group and in 17 (12%) in the basal-bolus group (p=0·45). No differences in hospital complications were noted between groups. Seven patients (5%) developed acute kidney injury in the sitagliptin-basal group and six (4%) in the basal-bolus group. One patient (0·7%) developed acute pancreatitis (in the basal-bolus group).

INTERPRETATION

The trial met the non-inferiority threshold for the primary endpoint, because there was no significant difference between groups in mean daily blood glucose concentrations. Treatment with sitagliptin plus basal insulin is as effective and safe as, and a convenient alternative to, the labour-intensive basal-bolus insulin regimen for the management of hyperglycaemia in patients with type 2 diabetes admitted to general medicine and surgery services in hospital in the non-intensive-care setting.

FUNDING

Merck.

Dynamics in insulin requirements and treatment safety

AIMS

The majority of insulin users have elevated HbA1c. There is growing recognition that the low success rates are due to variations in insulin requirements. Thus, frequent dosage adjustments are needed. In practice, adjustments occur sporadically due to limited provider availability. We investigated intra-individual dynamics of insulin requirements using data from a service evaluation of the d-Nav® Insulin Guidance Service. This service facilitates automated insulin dosage adjustments, as often as needed, to achieve and maintain optimal glycemic balance.

METHODS

Data were collected from subjects who have been using the service for more than a year. Events of considerable and persistent decrease in insulin requirements were identified by drops in total daily insulin ≥25%.

RESULTS

Overall, 62 patients were studied over an average period of 2.1±0.5 (mean±standard deviation) years. Stability in HbA1c was attained after ~3 quarters at 7.4%±0.2% (57.4mmol/mol±1mmol/mol). Events were identified in 56.5% of the patients. On average, each affected patient had 0.8±0.4 events per year, lasting 9.7±6.6weeks, while total daily insulin dosage decreased by 41.4±13.4%.

CONCLUSIONS

Our findings may call attention to a major contributing factor to hypoglycemia among insulin users. In reality, insulin dosage is seldom adjusted and thus transient periods of decrease in insulin requirements and overtreatment are usually overlooked.

A novel approach to optimise glycaemic control in insulin users

Insulin therapy has been available for almost a century. However, its success rate is still disappointing where the majority of users sustain harmfully elevated glycated haemoglobin (HbA1c) levels. The key element essential for effective and safe insulin therapy is frequent dosage titration to overcome constant variations in insulin requirements. In reality, dosage titration is done sporadically during clinic visits. A scalable solution to this problem is being reviewed. A diabetes nurses service improves glycaemic control without overburdening the health system. The service relies on a handheld device, which provides patients with an insulin dose recommendation for each injection while using the device to monitor glucose. Similar to the approach providers use during clinical encounters, the device analyses stored glucose trends and constantly titrates insulin dosage without care providers' supervision. In this report, we describe the logic behind the technology by providing examples from users.

Histological insights into the pathogenesis of post-Roux-en-Y hyperinsulinaemic hypoglycaemia

BACKGROUND

β-cell hyperplasia has been implicated in the aetiology of post Roux-en-Y gastric bypass hyperinsulinaemic hypoglycaemia, but the pathogenesis of this condition is still unclear.

CASE REPORT

We report a case of a 52-year-old man with post-Roux-en-Y gastric bypass hyperinsulinaemic hypoglycaemia who underwent distal pancreatectomy to alleviate his symptoms. Pancreatic histopathology showed chronic pancreatitis with a corresponding loss of exocrine tissue and islet retention. Amyloid deposition was found in pancreatic islets. These features are more typically associated with Type 2 diabetes.

DISCUSSION

This case highlights the potential multifactorial pathogenesis of symptomatic hypoglycaemia after Roux-en-Y gastric bypass.

Insulin therapy for pre-hyperglycemic beta-cell endoplasmic reticulum crowding

Insulin therapy improves β-cell function in early stages of diabetes by mechanisms that may exceed alleviation of glucotoxicity. In advance type 2 diabetes, hyperglycemia causes β-cell damage and ultimately β-cell loss. At such an advanced stage, therapeutic modalities are often inadequate. Growing evidence indicates that in early stages of type-2 diabetes and some types of monogenic diabetes linked with malfunctioning endoplasmic-reticulum (ER), the β-cell ER fails to process sufficient proinsulin once it becomes overloaded. These changes manifest with ER distention (ER-crowding) and deficiency of secretory granules. We hypothesize that insulin therapy may improves β-cell function by alleviating ER-crowding. To support this hypothesis, we investigated pre-diabetic β-cell changes in hProC(A7)Y-CpepGFP transgenic mice that develop prolonged pre-diabetes due to proinsulin dysmaturation and ER-crowding. We attenuated the β-cell ER proinsulin synthesis with a treat-to-target insulin therapy while avoiding hypoglycemia and weight gain. Alleviation of ER-crowding resulted in temporary improvement in proinsulin maturation, insulin secretion and glucose tolerance. Our observations suggest that alleviation of pre-diabetic ER-crowding using a treat-to-target insulin therapy may improve β-cell function and may prevent further metabolic deterioration.

Can a tool that automates insulin titration be a key to diabetes management?

BACKGROUND

Most patients who use insulin do not achieve optimal glycemic control and become susceptible to complications. Numerous clinical trials have shown that frequent insulin dosage titration is imperative to achieve glycemic control. Unfortunately, implementation of such a paradigm is often impractical. We hypothesized that the Diabetes Insulin Guidance System (DIGS™) (Hygieia, Inc., Ann Arbor, MI) software, which automatically advises patients on adjustment of insulin dosage, would provide safe and effective weekly insulin dosage adjustments.

SUBJECTS AND METHODS

In a feasibility study we enrolled patients with type 1 and type 2 diabetes, treated with a variety of insulin regimens and having suboptimal glycemic control. The 12-week intervention period followed a 4-week baseline run-in period. During the intervention, DIGS processed patients' glucose readings and provided insulin dosage adjustments on a weekly basis. If approved by the study team, the adjusted insulin dosage was communicated to the patients. Insulin formulations were not changed during the study. The primary outcome was the fraction of DIGS dosage adjustments approved by the study team, and the secondary outcome was improved glycemic control.

RESULTS

Forty-six patients were recruited, and eight withdrew. The DIGS software recommended 1,734 insulin dosage adjustments, of which 1,731 (99.83%) were approved. During the run-in period the weekly average glucose was stable at 174.2±36.7 mg/dL (9.7±2.0 mmol/L). During the following 12 weeks, DIGS dosage adjustments resulted in progressive improvement in average glucose to 163.3±35.1 mg/dL (9.1±1.9 mmol/L) (P<0.03). Mean glycosylated hemoglobin decreased from 8.4±0.8% to 7.9±0.9% (P<0.05). Concomitantly, the frequency of hypoglycemia decreased by 25.2%.

CONCLUSIONS

The DIGS software provided patients with safe and effective weekly insulin dosage adjustments. Widespread implementation of DIGS may improve the outcome and reduce the cost of implementing effective insulin therapy.

Frequent insulin dosage adjustments based on glucose readings alone are sufficient for a safe and effective therapy

PROBLEM

Frequent dosage adjustments are necessary to achieve effective insulin therapy. However, a controversy surrounds the pertinent clinical parameters required to make effective and safe insulin titrations. We hypothesize that glucose readings are sufficient to adjust insulin dosage provided that it is done on a weekly basis.

METHODS

In a prospective pilot study, we recruited 14 subjects with suboptimally controlled insulin-treated Type-2 and Type-1 diabetes. Subjects were treated with basal-bolus insulin therapy that was titrated weekly for 12 weeks. Dosage adjustments were made by the study Endocrinologist by reviewing subjects' glucose readings, exclusively based on logsheets and contingent upon the approval of the on-site study team. To corroborate that the glucose readings were sufficient for making dosage adjustments, we used software to process only glucose readings and recommend insulin dosage adjustments. The recommendations made by the software were retrospectively compared to the ones made by the study Endocrinologist.

RESULTS

All N=568 recommendations were approved by the study team and in 99.3% of the cases the recommendations were clinically similar to the ones made by the software. No hazardous disagreements were found. The mean A1C improved from 9.8% (± 2.0) to 7.9% (± 1.3) (p=0.001) in 12 weeks and the weekly mean glucose progressively improved from 220.3 mg/dl (± 51.9) to 151.5 mg/dl (± 19.2) (p<0.0001). The frequency of minor hypoglycemia was 22.7 per patient-year in subjects with Type-2 diabetes and 42.7 in the subjects with Type-1 diabetes. No severe hypoglycemic events occurred.

CONCLUSIONS

Glucose readings are sufficient to adjust insulin therapy in a safe and effective manner, when adjustments are made on a weekly basis. Thus, dedicated software may help adjust insulin dosage between clinic visits.

The effort required to achieve and maintain optimal glycemic control

BACKGROUND

Insulin therapy is most effective when dosage is frequently adjusted. We sought to evaluate the effort required to maintain A1C below 7% once attained in older patients with type 2 diabetes.

METHODS

A total of 2380 insulin dosage adjustment episodes were analyzed for their intensity and frequency. The data were divided into an "induction period" (n=608), defined as the time before subjects' A1C dropped below 7% for the first time, and a "maintenance period" (n=1772), defined as the remaining study period. The data originated from a published study and included 26 older subjects with suboptimally controlled type 2 diabetes treated for a year with intensive insulin therapy. To achieve therapy goals, the study team contacted the subjects once every few weeks, reviewed records and optimized the insulin dosage.

RESULTS

During both the induction and maintenance periods, insulin dosage (both long-acting and fast-acting) was adjusted by more than 20%. Maintaining A1C below 7% required dosage adjustments every 2.7(±1.0) weeks, averaging 11.4% (±4.0) in 2.0 (±0.3) different components of insulin dosage (i.e., two of either long-acting or short-acting for breakfast, lunch or dinner) per contact.

CONCLUSIONS

Considerable effort was required to maintain optimal A1C levels in older patients with type 2 diabetes. Since the full benefit of insulin therapy is attained only when multiple components of insulin dosage are frequently adjusted and given the growing shortage of care providers' availability, innovative approaches are needed to empower patients to safely make their own insulin adjustments.

In vivo misfolding of proinsulin below the threshold of frank diabetes

OBJECTIVE

Endoplasmic reticulum (ER) stress has been described in pancreatic β-cells after onset of diabetes-a situation in which failing β-cells have exhausted available compensatory mechanisms. Herein we have compared two mouse models expressing equally small amounts of transgenic proinsulin in pancreatic β-cells.

RESEARCH DESIGN AND METHODS

In hProCpepGFP mice, human proinsulin (tagged with green fluorescent protein [GFP] within the connecting [C]-peptide) is folded in the ER, exported, converted to human insulin, and secreted. In hProC(A7)Y-CpepGFP mice, misfolding of transgenic mutant proinsulin causes its retention in the ER. Analysis of neonatal pancreas in both transgenic animals shows each β-cell stained positively for endogenous insulin and transgenic protein.

RESULTS

At this transgene expression level, most male hProC(A7)Y-CpepGFP mice do not develop frank diabetes, yet the misfolded proinsulin perturbs insulin production from endogenous proinsulin and activates ER stress response. In nondiabetic adult hProC(A7)Y-CpepGFP males, all β-cells continue to abundantly express transgene mRNA. Remarkably, however, a subset of β-cells in each islet becomes largely devoid of endogenous insulin, with some of these cells accumulating large quantities of misfolded mutant proinsulin, whereas another subset of β-cells has much less accumulated misfolded mutant proinsulin, with some of these cells containing abundant endogenous insulin.

CONCLUSIONS

The results indicate a source of pancreatic compensation before the development of diabetes caused by proinsulin misfolding with ER stress, i.e., the existence of an important subset of β-cells with relatively limited accumulation of misfolded proinsulin protein and maintenance of endogenous insulin production. Generation and maintenance of such a subset of β-cells may have implications in the avoidance of type 2 diabetes.

Are glucose readings sufficient to adjust insulin dosage?

AIMS/HYPOTHESIS

insulin therapy is effective predominantly when dosage is frequently adjusted. However, a controversy surrounds the pertinent clinical parameters required to make effective and safe frequent dosage adjustments. We hypothesize that glucose readings are sufficient to adjust insulin dosage provided that dosage is adjusted every 1-4 weeks.

METHODS

to test the hypothesis, we generated several algorithms implemented in software to process glucose readings and recommend insulin dosage adjustments. A post hoc analysis was made on 630 log sheets (2,520 insulin dosage adjustments) from 26 older adults with suboptimally controlled type 2 diabetes. The subjects were followed for a year and treated with intensive insulin therapy that was titrated every 1-4 weeks by a trained study team. More than 88% of subjects attained the treatment goal (hemoglobin A1c <7%) without excessive hypoglycemia. Glucose readings from each log sheet were used as an input to the software, and its recommendations for insulin dosage adjustments were compared to the original ones made by the study team. While the study team could have been exposed to multiple clinical parameters, the software relied solely on glucose readings.

RESULTS

the software recommendations for dosage adjustments were clinically equivalent to the original study team's recommendations in more than 95% of the cases, unrelated to patients' insulin sensitivity. The remaining 4.4% (n = 111) were thoroughly examined, yet we did not find any recommendations suggested by the software to be unsafe or unreasonable.

CONCLUSIONS/INTERPRETATION

glucose readings are sufficient to effectively adjust insulin dosage provided that adjustments are made every 1-4 weeks. Therefore, dedicated software can help adjusting insulin dosage between clinic visits.

Proinsulin misfolding and diabetes: mutant INS gene-induced diabetes of youth

Type 1B diabetes (typically with early onset and without islet autoantibodies) has been described in patients bearing small coding sequence mutations in the INS gene. Not all mutations in the INS gene cause the autosomal dominant Mutant INS-gene Induced Diabetes of Youth (MIDY) syndrome, but most missense mutations affecting proinsulin folding produce MIDY. MIDY patients are heterozygotes, with the expressed mutant proinsulins exerting dominant-negative (toxic gain of function) behavior in pancreatic beta cells. Here we focus primarily on proinsulin folding in the endoplasmic reticulum, providing insight into perturbations of this folding pathway in MIDY. Accumulated evidence indicates that, in the molecular pathogenesis of the disease, misfolded proinsulin exerts dominant effects that initially inhibit insulin production, progressing to beta cell demise with diabetes.

Misfolded proinsulin affects bystander proinsulin in neonatal diabetes

It has previously been shown that misfolded mutant Akita proinsulin in the endoplasmic reticulum engages directly in protein complexes either with nonmutant proinsulin or with "hProCpepGFP" (human proinsulin bearing emerald-GFP within the C-peptide), impairing the trafficking of these "bystander" proinsulin molecules (Liu, M., Hodish, I., Rhodes, C. J., and Arvan, P. (2007) Proc. Natl. Acad. Sci. U.S.A. 104, 15841-15846). Herein, we generated transgenic mice, which, in addition to expressing endogenous proinsulin, exhibit beta-cell-specific expression of hProCpepGFP via the Ins1 promoter. In these mice, hProCpepGFP protein levels are physiologically regulated, and hProCpepGFP is packaged and processed to CpepGFP that is co-stored in beta-secretory granules. Visualization of CpepGFP fluorescence provides a quantifiable measure of pancreatic islet insulin content that can be followed in live animals in states of health and disease. We examined loss of pancreatic insulin in hProCpepGFP transgenic mice mated to Akita mice that develop neonatal diabetes because of the expression of misfolded proinsulin. Loss of bystander insulin in Akita animals is detected initially as a block in CpepGFP/insulin production with intracellular accumulation of the precursor, followed ultimately by loss of pancreatic beta-cells. The data support that misfolded proinsulin perturbs bystander proinsulin in the endoplasmic reticulum, leading to beta-cell failure.

Location of ectopic adrenocortical hormone-secreting tumors causing Cushing's syndrome in the paranasal sinuses

BACKGROUND

The majority of ectopic adrenocorticotropic hormone (ACTH)-secreting tumors are localized in the chest or abdomen. Occasionally, these tumors are found in the paranasal sinuses.

METHODS

We present 2 unusual cases of ectopic ACTH syndrome whose ACTH-secreting tumors were localized in the paranasal sinuses and describe their biochemical and radiological presentation.

RESULTS

The first patient had an ACTH-secreting olphactory neuroblastoma originating in the ethmoid sinuses. The second patient had a clinical course and biochemical findings indistinguishable from pituitary ACTH-dependent Cushing's syndrome, except for negative petrosal sinus sampling. Head imaging showed a "polyp" in the left maxillary sinus-secreting ACTH. Both patients went into remission following surgical resection and recovered normal pituitary-adrenal axis function.

CONCLUSION

Ectopic ACTH secretion may originate from lesions in the paranasal sinuses. This accessible location allows for direct immunohistochemical diagnosis with ACTH staining. Surgical resection/radiation therapy can result in complete remission of the disease and restoration of normal pituitary-adrenal function.

Proinsulin maturation, misfolding, and proteotoxicity

As a tool to explore proinsulin (PI) trafficking, a human PI cDNA has been constructed with GFP fused within the C peptide. In regulated secretory cells containing appropriate prohormone convertases, the hProCpepGFP construct undergoes endoproteolytic processing to CpepGFP and native human insulin, which are specifically detected and cosecreted in parallel with endogenous insulin. Expression of C(A7)Y mutant PI results in autosomal dominant diabetes in Akita mice. We directly identify the misfolded PI in Akita islets and also show that C(A7)Y mutant PI, either in the context of the hProCpepGFP chimera or not, engages directly in protein complexes with nonmutant PI, impairing the trafficking and recovery of nonmutant PI. This trapping mechanism decreases insulin production in beta cells. Thereafter we observe a loss of beta cell viability. The data imply that PI misfolding leading to impaired endoplasmic reticulum exit of nonmutant PI may be a key early step in a chain reaction of beta cell dysfunction and demise leading to onset and progression of diabetes.

Inhibition of carcinogenesis in transgenic mouse models over-expressing 15-lipoxygenase in the vascular wall under the control of murine preproendothelin-1 promoter

Oxygenases are a family of enzymes that dioxygenate unsaturated fatty acids, thus initiating membrane oxidation and signaling molecule synthesis. The lipoxygenases (LOs), a family of lipid-peroxidizing enzymes that induce structural and metabolic changes in the cell in a number of pathophysiological conditions, belong to the oxygenases family. This class of enzymes has several subgroups, named 5-, 8-, 12- and 15-LOs, and these LO-isoforms are capable of oxygenating arachidonic and linoleic acid. 15-LOs were reported to play an inhibitory role in tumor angiogenesis and, consequently, they slow down carcinogenesis. It has been suggested that its anti-carcinogenic effect is conferred by promoting cell differentiation and apoptosis. Using transgenic mice that over-express 15-LO-1 in endothelial cells under the regulation of the murine preproendothelin-1 promoter, we studied its effect on tumor and metastasis growth. We found that 15-LO-1 inhibited tumor and metastasis growth in the transgenic mice in two different models of cancer (mammary gland and Lewis lung carcinoma). This inhibition was concomitant with a higher number of apoptotic cells in the metastases of the transgenic mice and with a complicated network of multiple small blood vessels. This finding targets 15-LO as a new candidate in the treatment of carcinogenesis.

Transcription-controlled gene therapy against tumor angiogenesis

A major drawback of current approaches to antiangiogenic gene therapy is the lack of tissue-specific targeting. The aim of this work was to trigger endothelial cell-specific apoptosis, using adenoviral vector-mediated delivery of a chimeric death receptor derived from the modified endothelium-specific pre-proendothelin-1 (PPE-1) promoter. In the present study, we constructed an adenovirus-based vector that targets tumor angiogenesis. Transcriptional control was achieved by use of a modified endothelium-specific promoter. Expression of a chimeric death receptor, composed of Fas and TNF receptor 1, resulted in specific apoptosis of endothelial cells in vitro and sensitization of cells to the proapoptotic effect of TNF-alpha. The antitumoral activity of the vectors was assayed in two mouse models. In the model of B16 melanoma, a single systemic injection of virus to the tail vein caused growth retardation of tumor and reduction of tumor mass with central tumor necrosis. When the Lewis lung carcinoma lung-metastasis model was applied, i.v. injection of vector resulted in reduction of lung-metastasis mass, via an antiangiogenic mechanism. Moreover, by application of the PPE-1-based transcriptional control, a humoral immune response against the transgene was avoided. Collectively, these data provide evidence that transcriptionally controlled, angiogenesis-targeted gene therapy is feasible.

Effect of elevated homocysteine levels on clinical restenosis following percutaneous coronary intervention

Since hyperhomocysteinemia confers a prothrombotic effect and promotes proliferation of smooth muscle cells in response to vascular injury, it might be implicated in the pathogenesis of restenosis after percutaneous coronary intervention (PCI). Our study comprised 55 patients who underwent successful PCI in the acute myocardial infarction (AMI) course. Homocysteine levels were determined within 24 h of admission. During a 1-year follow-up, 16 patients (31%) underwent repeated coronary angiography for recurrent angina or re-infarction, which demonstrated re-narrowing of > or =50% at the qualifying PCI site (clinical restenosis). Irrespective of stent deployment, clinical restenosis was not associated with higher homocysteine levels (12 +/- 7 vs. 14 +/- 11 micromol/l, p = 0.77). There was no correlation between homocysteine levels and time to restenosis (r(2) = 0.06, p = 0.35). In conclusion, elevated homocysteine levels do not predict a higher incidence of restenosis after PCI.

Intravitreal gas injection for hypotony after cataract surgery

PURPOSE

To evaluate the efficacy and safety of intravitreal perfluoropropane gas injection to treat hypotony after cataract surgery.

SETTING

The ophthalmology department of a major tertiary medical center.

METHODS

After uneventful cataract extraction, 5 patients with hypotony due to iridocyclitis, choroidal detachment, and serous retinal detachment were treated with an intravitreal injection of 1.0 cc of perfluoropropane gas.

RESULTS

The hypotony, choroidal detachment, and exudative retinal detachment resolved in all 5 patients, and visual acuity improved. No complications were observed.

CONCLUSION

Intravitreal gas injection can be used to treat hypotony after cataract surgery in selected patients.

[Frequency of the Gaucher mutation among recent Russian immigrants]

Gaucher's disease is frequent in the Ashkenazi Jewish population of Israel, with a gene frequency by molecular analysis of approximately 0.032, corresponding to a birth rate of 1:850. The recent immigration from the former Soviet Union brought more than 400,000 Jews, mostly of Ashkenazi descent. However, only a few cases of Gaucher's disease have been diagnosed. Possible explanations are lack of awareness of the signs of Gaucher's disease among Russian health workers and family practitioners in Israel, and a significantly lesser frequency of the Gaucher gene among Russian immigrants than among other Ashkenazi Jews in Israel and the US. We studied the frequency of the 1226G (N370S) mutation in a cohort of 202 recent immigrants from the former Soviet Union. We found 10 carriers (4.95%), indicating a decreased frequency of the Gaucher gene, but by extension, the probability of unidentified cases in need of treatment. Family practitioners should be aware of the possibility that heretofore misdiagnosed symptoms may be those of Gaucher's disease.