Insulin secretion and action and the response of endogenous glucose production to a lack of glucagon suppression in non-diabetic subjects

Type 2 diabetes is a disease characterized by impaired insulin secretion and defective glucagon suppression in the postprandial period. We examined the effect of impaired glucagon suppression on glucose concentrations and Endogenous Glucose Production (EGP) at different degrees of insulin secretory impairment. The contribution of anthropometric characteristics, peripheral, and hepatic insulin action to this variability was also examined. To do so, we studied 54 non-diabetic subjects on two occasions in which endogenous hormone secretion was inhibited by somatostatin, with glucagon infused at a rate of 0.65 ng/kg/min, at 0 min to prevent a fall in glucagon (non-suppressed day) or at 120 min to create a transient fall in glucagon (suppressed day). Subjects received glucose (labeled with [3-3H]-glucose) infused to mimic the systemic appearance of 50g oral glucose. Insulin was infused to mimic a prandial insulin response in 18 subjects, another 18 received 80% of the dose and the remaining 18 received 60%. EGP was measured using the tracer-dilution technique. Decreased prandial insulin resulted in greater % increase in peak glucose but not in integrated glucose concentrations attributable to non-suppressed glucagon. The % change in integrated EGP was unaffected by insulin dose. Multivariate regression analysis, adjusted for age, sex, weight and insulin dose, did not show a relationship between the EGP response to impaired suppression of glucagon and insulin action as measured at the time of screening by oral glucose tolerance. A similar analysis for hepatic insulin action also did not show a relationship with the EGP response. These data indicate that the effect of impaired glucagon suppression on EGP is independent of anthropometric characteristics and insulin action.

The first and only combination of basal and prandial insulin analogs degludec and aspart: the position of Russian endocrinologists

Insulin therapy for diabetes mellitus is the most effective way to control glycemia with the progression of the disease and the ineffectiveness of other sugar-lowering drugs. At the same time, the existing limitations of traditional insulin preparations, along with increasing attention to the individualized treatment of this disease, are pushing developers to create drugs that most closely reproduce the effect of natural human insulin. In this regard, the appearance of a combination of insulin analogs, the action profile of which practically imitates insulin secretion by a healthy pancreas, presents new possibilities in the treatment of diabetes mellitus. Insulin degludec / insulin aspart (IDegAsp, Ryzodeg®, Novo Nordisk, Denmark) is the first and only soluble combination preparation containing 70% of the ultra-long-acting insulin analogue degludec and 30% of the ultra-short-acting insulin analogue aspart in one injection, which meets the need for both basal and prandial insulin. The combined drug has nothing in common with traditional mixed insulin preparations (both human and analog) and provides doctors and patients with significant advantages over the latter. The article presents the position of Russian experts-diabetologists with extensive experience in the use of IDegAsp regarding the role and place of the drug in real clinical practice. Data from real clinical practice confirm that IDegAsp is a reasonable choice for starting and intensifying insulin therapy for type 2 diabetes mellitus when basal and prandial glycemic control is required. The use of the drug is most appropriate in patients who are on basal, biphasic, basal-plus/basal-bolus regimens and who do not achieve the goals of glycemic control during prior therapy. One of the leading reasons for choosing IDegAsp may also be a lower risk of developing hypoglycemia compared to insulin analogues of previous generations — biphasic insulin aspart and basal insulin glargine 100 U/ml. In addition, IDegAsp is a simple, flexible and safe insulin therapy for patients on premix therapy and basal-plus/basis-bolus regimens who require basal and prandial glycemic control. IDegAsp is a simple, flexible and safe insulin therapy. The greatest benefit of this drug use can be obtained by patients for whom adherence to a complex therapy regimen is difficult (the elderly, with cognitive impairment, after a stroke, with dementia), as well as patients who have an active lifestyle, accompanied by irregular food intake. It is important to note that since January 1, 2021, there is no need for a decision by a special medical commission to prescribe (IDegAsp) Ryzodeg®. This fact, as well as a significant price reduction at the end of 2020, opens up broader prospects for using the drug in the routine practice of a Russian endocrinologist.

Two Extremes of Dysglycemia- a Rare Case of Diabetes Complicated With a Non-Functional Pancreatic Neuroendocrine Tumor Transforming to an Insulinoma

Background: Diabetes is characterized by hyperglycemia with heterogeneous pathophysiological features and varied presentation and consequences. Here, we present a rare case of diabetes that was complicated with insulinoma making glycemia management complicated. Clinical Case: A 48-year-old white man was diagnosed with diabetes when he presented with weight loss, polyuria and polydipsia and HbA1c of 11%. He was treated with oral agents for few months without a good response then switched to insulin. He was assumed to have type 1 diabetes and had fairly well controlled glycemia on multi daily injection of insulin. He was diagnosed with a metastatic non-functional pancreatic neuroendocrine tumor (PTEN) 9 years later. He presented with epigastric pain and CT scan showed a mass in the pancreas tail and multiple lesions in liver. The tumor was immunopositive for S100, synaptophysin, and chromogranin. He was first treated with sunitinib and later switched to Everolimus. He underwent treatment with SIR-spheres which was complicated with post-embolization syndrome and Diabetes Ketoacidosis (DKA). He was switched back to Everolimus and referred to the endocrinology clinic for management of diabetes with a recent DKA. At the initial evaluation by the endocrinology team, he had BMI of 25 kg/m2, no significant family history of diabetes, no diagnosis of dyslipidemia or hypertension. He had low C-peptide < 0.1 ng/mL (n: 0.8 - 5.2 ng/mL) and negative GAD antibody suggestive of non-immune mediated insulin deficient diabetes. He was treated with basal plus prandial insulin regimen and required about 0.6–0.7 unit/kg of insulin each day. Due to progression of PTEN, he was started on monthly Lanreotide while later Pembrolizumab was added resulting in hypothyroidism with a TSH of 75 mIU/L (n: 0.45 - 5.33 mIU/L) that was treated with Levothyroxine. Meanwhile, his diabetes care was complicated by recurrent hypoglycemic episodes and hypoglycemia unawareness. He gradually decreased the dose of insulin, stopped taking prandial insulin, and finally discontinued basal insulin due to recurrent hypoglycemia. He continued to have hypoglycemia despite stopping insulin. His C-peptide was found to be 3.3 ng/mL with a low BG of 62 mg/dl. Diazoxide was started and despite maximizing the dose, the patient continued experiencing hypoglycemia. He therefore decided to stop taking Diazoxide and only continued monthly Lanreotide. The patient is currently avoiding hypoglycemia by eating frequently (every 3 hours) and has regained his hypoglycemia awareness. Conclusion: This is a rare case of non-immune mediated insulin deficient diabetes complicated by recurrent episodes of hypoglycemia due to a non-functioning PNET converting to a functional tumor producing insulin.

The Effect of Prandial Insulin Applied for Fat Protein Units on Postprandial Glucose Excursions in Type 1 Diabetes Patients with Insulin Pump Therapy: Results of a Randomized, Controlled, Cross-Over Study

Objective This randomized cross-over study aimed to compare different algorithms for calculating prandial insulin considering the fat and protein content of a standardized meal in type 1 diabetes patients using insulin pump therapy (CSII). Methods Twenty-six patients received a standardized evening meal for three consecutive days using different algorithms for insulin dose adjustment: A) exclusive consideration of carbohydrate content without considering fat-protein content, B) high-dose algorithm considering additional insulin for fat protein units (FPUs) with the same factor as for carbohydrates, and C) low-dose algorithm considering additional insulin for FPUs with half the factor as for carbohydrates. The primary outcome was the proportion of interstitial glucose values in the target range (≥ 70 to ≤ 180 mg/dl) during the post-prandial 12-hour follow-up period. Secondary outcomes were the occurrence of hypo- and hyperglycemic episodes and the coverage with carbohydrates for treatment of hypoglycemia. Results The percentage of glucose values in the target range was significantly higher when fat-protein content was not considered, whereas, in the hyperglycemic range, it did not differ significantly among the three groups. The percentage of hypoglycemic glucose values were the highest in the groups considering fat-protein content and lowest in the group not considering FPUs with no significant difference between the two groups in terms of FPUs. Conclusions In adult type 1 diabetes patients using CSII, it is not recommended to consider a high fat and protein content in the diet when calculating prandial insulin dosage with the selected algorithms, as this increases the risk of hypoglycemia disproportionately.