More uniform diurnal blood glucose control and a reduction in daily insulin dosage on addition of glibenclamide to insulin in type 1 diabetes mellitus: role of enhanced insulin sensitivity

Glucose-Lowering Therapy beyond Insulin in Type 1 Diabetes: A Narrative Review on Existing Evidence from Randomized Controlled Trials and Clinical Perspective

Background: In Type 1 diabetes (T1D), according to the most recent guidelines, the everyday glucose-lowering treatment is still restricted to the use of subcutaneous insulin, while multiple therapeutic options exist for Type 2 diabetes (T2D). Methods: For this narrative review we unsystematically screened PubMed and Embase to identify clinical trials which investigated glucose-lowering agents as an adjunct to insulin treatment in people with T1D. Published studies up to March 2022 were included. We discuss the safety and efficacy in modifying cardiovascular risk factors for each drug, the current status of research, and provide a clinical perspective. Results: For several adjunct agents, in T1D, the scientific evidence demonstrates improvements in HbA1c, reductions in the risk of hypoglycemia, and achievements of lower insulin requirements, as well as positive effects on cardiovascular risk factors, such as blood lipids, blood pressure, and weight. As the prevalence of obesity, the major driver for double diabetes, is rising, weight and cardiovascular risk factor management is becoming increasingly important in people with T1D. Conclusions: Adjunct glucose-lowering agents, intended to be used in T2D, bear the potential to beneficially impact on cardiovascular risk factors when investigated in the T1D population and are suggested to be more extensively considered as potentially disease-modifying drugs in the future and should be investigated for hard cardiovascular endpoints.

Anti-Hyperglycemic Effects of Refined Fractions from Cyclocarya paliurus Leaves on Streptozotocin-Induced Diabetic Mice

To identify the chemical components responsible for the anti-hyperglycemic effect of Cyclocarya paliurus (Batal.) Iljinsk (Juglandaceae) leaves, an ethanol extract (CPE) and a water extract (CPW) of C. paliurus leaves, as well as their total flavonoids (CPF), triterpenoids (CPT) and crude polysaccharides (CPP), were prepared and assessed on streptozotocin (STZ)-induced diabetic mice. After being orally administrated once a day for 24 days, CPF (300 mg/kg), CPP (180 mg/kg), or CPF+CPP (300 mg/kg CPF + 180 mg/kg CPP) treatment reversed STZ-induced body weight and muscle mass losses. The glucose tolerance tests and insulin tolerance tests suggested that CPF, CPP, and CPF+CPP showed anti-hyperglycemic effect in STZ-induced diabetic mice. Furthermore, CPF enhances glucose-stimulated insulin secretion in MIN6 cells and insulin-stimulated glucose uptake in C2C12 myotubes. CPF and CPP suppressed inflammatory cytokine levels in STZ-induced diabetic mice. Additionally, CPF and CPP improved STZ-induced diabetic nephropathy assessed by H&E staining, blood urea nitrogen content, and urine creatinine level. The molecular networking and Emperor analysis results indicated that CPF showed potential anti-hyperglycemic effects, and HPLC–MS/MS analysis indicated that CPF contains 3 phenolic acids and 9 flavonoids. In contrast, CPT (650 mg/kg) and CPC (300 mg/kg CPF + 180 mg/kg CPP + 650 mg/kg CPT) did not show anti-hyperglycemic effect. Taken together, polysaccharides and flavonoids are responsible for the anti-hyperglycemic effect of C. paliurus leaves, and the clinical application of C. paliurus need to be refined.

Efficacy of Sulfonylureas with Insulin in Type 2 Diabetes Mellitus

BACKGROUND:

In subjects with type 2 diabetes mellitus, glycemic control deteroriates while patients use sulfonylurea drugs during the course of the disease. Adjunctive therapy with insulin at this stage requires a lesser daily insulin dose in comparison with insulin monotherapy while restoring desirable glycemic control. However, data regarding direct comparison between various sulfonylureas in this regard are lacking.

OBJECTIVE:

To examine comparative efficacies of adjunctive therapy with insulin in subjects with type 2 diabetes manifesting lapse of glycemic control while receiving various individual sulfonylurea drugs.

METHODS:

Four groups of 10 subjects, each presenting with glycosylated hemoglobin (HbA1C) >8.0% while using either tolazamide, glyburide, glipizide Gastrointestinal Therapeutic System (GITS), or glimepiride, were recruited. Two from each group were randomized to receive placebo; the others continued the same drug. Pre-supper subcutaneous 70 NPH/30 regular insulin was initiated at 10 units and gradually increased and adjusted as necessary to attain fasting blood glucose levels between 80 and 120 mg/dL and maintain the same range for 6 months. Fasting plasma glucose, plasma C-peptide, and HbA1C concentrations were determined prior to the addition of insulin and at the end of the study. Daily insulin dose and changes in body weight (BW) were noted at the end of the study, and the number of hypoglycemic events during the last 4 weeks of the study was determined.

RESULTS:

Daily insulin dose (units/kg BW), weight gain, and number of hypoglycemic events were significantly lower (p < 0.01) in subjects receiving sulfonylureas in comparison with placebo. However, the daily insulin dose alone was significantly lower (p < 0.05) with glimepiride (0.49 ± 0.10; mean ± SE) than with other sulfonylureas (tolazamide 0.58 ± 0.12, glyburide 0.59 ± 0.12, glipizide GITS 0.59 ± 0.14). Finally, a significant correlation (r = 0.68; p < 0.001) was noted between suppression of plasma C-peptide level and the daily insulin dose among all participants.

CONCLUSIONS:

By lowering the daily insulin dose, sulfonylurea drugs appear to improve the sensitivity of exogenous insulin in subjects with type 2 diabetes mellitus manifesting lapse of glycemic control. Moreover, glimepiride appears to possess a greater insulin-sparing property than other sulfonylureas.

Estimating the effect of sulfonylurea on HbA1c in diabetes: a systematic review and meta-analysis

AIMS/HYPOTHESIS

Sulfonylureas are widely prescribed glucose-lowering medications for diabetes, but the extent to which they improve glycaemia is poorly documented. This systematic review evaluates how sulfonylurea treatment affects glycaemic control.

METHODS

Medline, EMBASE, the Cochrane Library and clinical trials registries were searched to identify double-blinded randomised controlled trials of fixed-dose sulfonylurea monotherapy or sulfonylurea added on to other glucose-lowering treatments. The primary outcome assessed was change in HbA1c, and secondary outcomes were adverse events, insulin dose and change in body weight.

RESULTS

Thirty-one trials with a median duration of 16 weeks were included in the meta-analysis. Sulfonylurea monotherapy (nine trials) lowered HbA1c by 1.51% (17 mmol/mol) more than placebo (95% CI, 1.25, 1.78). Sulfonylureas added to oral diabetes treatment (four trials) lowered HbA1c by 1.62% (18 mmol/mol; 95% CI 1.0, 2.24) compared with the other treatment, and sulfonylurea added to insulin (17 trials) lowered HbA1c by 0.46% (6 mmol/mol; 95% CI 0.24, 0.69) and lowered insulin dose. Higher sulfonylurea doses did not reduce HbA1c more than lower doses. Sulfonylurea treatment resulted in more hypoglycaemic events (RR 2.41, 95% CI 1.41, 4.10) but did not significantly affect the number of other adverse events. Trial length, sulfonylurea type and duration of diabetes contributed to heterogeneity.

CONCLUSIONS/INTERPRETATION

Sulfonylurea monotherapy lowered HbA1c level more than previously reported, and we found no evidence that increasing sulfonylurea doses resulted in lower HbA1c. HbA1c is a surrogate endpoint, and we were unable to examine long-term endpoints in these predominately short-term trials, but sulfonylureas appear to be associated with an increased risk of hypoglycaemic events.