The effects of purslane (Portulaca oleracea) on glycemic indices: A GRADE-assessed systematic review and meta-analysis of randomized controlled trials

Although several studies have revealed the benefits of purslane on glycemic indices, the results of some studies reject such effect. Therefore, aim of this meta-analysis of randomized controlled trials (RCTs) was to assess the effects of purslane supplementation on glycemic indices. Scientific international databases as Scopus, Web of Sciences, PubMed, Embase, and the Cochrane library were searched up to December 2022. For net changes in glycemic indices, weighted mean differences (WMDs) were calculated using random-effects models. Purslane supplementation had a statistically significant reduction in fasting blood glucose [FBG, WMD: -6.37; 95% CI: -9.34, -3.40, p < 0.001]. In addition, purslane did not significant effect on serum levels of insulin [WMD: -0.74; 95% CI: -2.58, 1.10; p = 0.430], homeostasis model assessment for insulin resistance [HOMA-IR, WMD: -0.25; 95% CI: -0.88, 0.37, p = 0.429], and QUICKI [WMD: -0.01; 95% CI: -0.01, 0.03, p = 0.317] compared with the control group. The results of our meta-analysis revealed a beneficial effect of purslane supplementation as a tool to decrease FBG levels, but not to HOMA-IR, insulin, and QUICKI levels. However, future high-quality, long-term clinical trials are needed to confirm our results.

Minimal and Maximal Models to Quantitate Glucose Metabolism: Tools to Measure, to Simulate and to Run in Silico Clinical Trials

Several models have been proposed to describe the glucose system at whole-body, organ/tissue and cellular level, designed to measure non-accessible parameters (minimal models), to simulate system behavior and run in silico clinical trials (maximal models). Here, we will review the authors' work, by putting it into a concise historical background. We will discuss first the parametric portrait provided by the oral minimal models-building on the classical intravenous glucose tolerance test minimal models-to measure otherwise non-accessible key parameters like insulin sensitivity and beta-cell responsivity from a physiological oral test, the mixed meal or the oral glucose tolerance tests, and what can be gained by adding a tracer to the oral glucose dose. These models were used in various pathophysiological studies, which we will briefly review. A deeper understanding of insulin sensitivity can be gained by measuring insulin action in the skeletal muscle. This requires the use of isotopic tracers: both the classical multiple-tracer dilution and the positron emission tomography techniques are discussed, which quantitate the effect of insulin on the individual steps of glucose metabolism, that is, bidirectional transport plasma-interstitium, and phosphorylation. Finally, we will present a cellular model of insulin secretion that, using a multiscale modeling approach, highlights the relations between minimal model indices and subcellular secretory events. In terms of maximal models, we will move from a parametric to a flux portrait of the system by discussing the triple tracer meal protocol implemented with the tracer-to-tracee clamp technique. This allows to arrive at quasi-model independent measurement of glucose rate of appearance (Ra), endogenous glucose production (EGP), and glucose rate of disappearance (Rd). Both the fast absorbing simple carbs and the slow absorbing complex carbs are discussed. This rich data base has allowed us to build the UVA/Padova Type 1 diabetes and the Padova Type 2 diabetes large scale simulators. In particular, the UVA/Padova Type 1 simulator proved to be a very useful tool to safely and effectively test in silico closed-loop control algorithms for an artificial pancreas (AP). This was the first and unique simulator of the glucose system accepted by the U.S. Food and Drug Administration as a substitute to animal trials for in silico testing AP algorithms. Recent uses of the simulator have looked at glucose sensors for non-adjunctive use and new insulin molecules.

The Padova Type 2 Diabetes Simulator from Triple-Tracer Single-Meal Studies: In Silico Trials Also Possible in Rare but Not-So-Rare Individuals

Background:In silico trials in type 2 diabetes (T2D) would be useful for testing diabetes treatments and accelerating the development of new antidiabetic drugs. In this study, we present a T2D simulator able to reproduce the variability observed in a T2D population. The simulator also allows to safely experiment on virtual subjects with severe (and possibly rare) pathological conditions. Methods: A meal simulation model of glucose, insulin, and C-peptide systems, made of 15 differential equations and 39 parameters, has been identified using a system decomposition and forcing function Bayesian strategy on data of 51 T2D subjects undergoing a single triple-tracer mixed meal. One hundred T2D in silico subjects have been generated from the joint distribution of estimated model parameters. A case study is presented to illustrate the simulator use for testing a virtual drug (improving insulin action and secretion) in a subpopulation of rare, extremely impaired, T2D subjects. Results: The model well fitted T2D data and parameters were estimated with precision. Simulated plasma glucose, insulin, and C-peptide well matched the data (e.g., median [25^th-75^th percentile] glucose area under the curves of 6.9 [6.1-8.5] 10⁴ mg/dL·min in silico vs. 7.0 [5.6-8.2] 10⁴ mg/dL·min in vivo). The potential use of the simulator was shown in a case study, in which the (virtual) antidiabetic drug dose was optimized for very insulin-resistant T2D subjects. Conclusions: We have developed a T2D simulator that captures the behavior of T2D population during a meal, both in terms of average and intersubject variability. The simulator represents a cost-effective way to test new antidiabetic drugs, before moving to human trials.

Interactions Between Gut Microbiota, Host, and Herbal Medicines: A Review of New Insights Into the Pathogenesis and Treatment of Type 2 Diabetes

Herbal medicines (HMs) are a major subset of complementary and alternative medicine. They have been employed for the efficient clinical management of type 2 diabetes mellitus (T2DM) for centuries. However, the related underlying mechanisms still remain to be elucidated. It has been found out that microbiota is implicated in the pathogenesis and treatment of T2DM. An interplay between gut microbiota and host occurs mainly at the gastrointestinal mucosal barrier. The host movements influence the composition and abundance of gut microbiota, whereas gut microbiota in turn modulate the metabolic and immunological activities of the host. Intestinal dysbiosis, endotoxin-induced metabolic inflammation, immune response disorder, bacterial components and metabolites, and decreased production of short-chain fatty acids are considered significant pathogenic mechanisms underlying T2DM. The interaction between gut microbiota and HMs during T2DM treatment has been investigated in human, animal, and in vitro studies. HMs regulate the composition of beneficial and harmful bacteria and decrease the inflammation caused by gut microbiota. Furthermore, the metabolism of gut microbiota modulates HM biotransformation. In this review, we have summarized such research findings, with the aim to improve our understanding of the pathogenesis and potential therapeutic mechanisms of HMs in T2DM and to provide new insights into specific targeted HM-based therapies and drug discovery.

Development of the Diabetes Injection Device Experience Questionnaire (DID-EQ) and Diabetes Injection Device Preference Questionnaire (DID-PQ)

BACKGROUND

Previous research has examined patient perceptions of insulin injection devices. However, injectable medications other than insulin are increasingly used to treat type 2 diabetes, including GLP-1 receptor agonists. No patient-reported outcome (PRO) instruments have been developed taking into account the experiences of patients using newer injection devices, which are often different from devices used for insulin. Therefore, the purpose of this qualitative study was to develop two draft PRO instruments focusing on patients' experiences with these newer injection devices (one instrument assessing perceptions of a single injection device, and another assessing preferences between two devices).

METHODS

Questionnaire development proceeded in six steps: literature review, interviews with six device experts, concept elicitation interviews with patients (N = 32), preliminary translatability assessment, cognitive interviews with patients (N = 20), and final translatability assessment.

RESULTS

Literature review and expert interviews were conducted to inform a concept elicitation interview guide. In concept elicitation in the US, UK, and Germany, patients with type 2 diabetes reported a range of injection features that influenced their perceptions of non-insulin injection devices (e.g., requirements for preparation of the medication/device, issues related to the needle, ease-of-use, portability). Two draft "item pools" were developed based on the literature review, expert interviews, and concept elicitation results. In cognitive interviews, patients recommended minor revisions and indicated that the draft instruments were generally clear, comprehensible, and relevant to their experience with non-insulin injectable medication. The instruments were refined based on the cognitive interviews and translatability assessment, resulting in two questionnaires.

CONCLUSIONS

The various steps of qualitative research support the content validity of these new PRO instruments, which are the first developed specifically to assess perceptions of non-insulin injection delivery systems. Despite some overlap with insulin-focused questionnaires, the new instruments are distinct from previous instruments (omitting content that would not be relevant to patients receiving non-insulin injectable treatment, while including content that is not included in the insulin focused instruments). This qualitative research yielded two draft questionnaires that are grounded in patient perceptions and ready for psychometric validation studies with larger samples of patients with type 2 diabetes.

Psychometric evaluation of the Diabetes Injection Device Experience Questionnaire (DID-EQ) and Diabetes Injection Device Preference Questionnaire (DID-PQ)

BACKGROUND

Previous research has examined patient perceptions of insulin injection devices. However, a range of injectable medications other than insulin are now used to treat type 2 diabetes. No patient-reported outcome (PRO) instruments have been developed taking into account the perceptions of patients using newer injection devices, which are often different from those used in the past. Therefore, the primary purpose of this study was to evaluate a new PRO instrument focusing on patients' experiences with injection devices, including those used for newer treatments such as GLP-1 receptor agonists.

METHODS

Patients with T2D treated with non-insulin injectable medications were recruited via advertisements and six clinical sites in the US. All participants completed the draft Diabetes Injection Device - Experience Questionnaire (DID-EQ) and additional measures administered for validity assessment. Participants who had experience with two non-insulin injection devices also completed the draft Diabetes Injection Device - Preference Questionnaire (DID-PQ). Analyses focused on item reduction (item performance, exploratory factor analysis), reliability, and validity.

RESULTS

One hundred fourty two patients (mean age = 63.0y; 56.3% female) participated. Item reduction yielded a 10-item version of the DID-EQ, including a 7-item Device Characteristics subscale and three global items assessing satisfaction, ease of use, and convenience of the injection device. The DID-EQ demonstrated good internal consistency reliability (Cronbach's alpha of Device Characteristics subscale = 0.80) and 7-day test-retest reliability (ICCs: 0.92 for Device Characteristics subscale; 0.65 to 0.91 for the three global items). Construct validity was demonstrated via correlations with previously validated instruments (e.g., correlations with the DTSQ treatment satisfaction subscale ranged from 0.56 to 0.60, all p < 0.0001; correlations with the TRIM-D Device ranged from 0.63 to 0.77, all p < 0.0001). Descriptive analyses of the DID-PQ were conducted with a subset of 27 participants who were able to use it to compare two devices.

CONCLUSIONS

This psychometric evaluation supports the reliability and validity of the DID-EQ, while providing initial information on the performance of the DID-PQ. These brief questionnaires complement measures of treatment efficacy and provide a more thorough picture of patients' experiences with non-insulin injectable treatments for type 2 diabetes.

Switching from sitagliptin to liraglutide to manage patients with type 2 diabetes in the UK: A long-term cost-effectiveness analysis

AIMS

The recent LIRA-SWITCH trial showed that switching from sitagliptin 100 mg to liraglutide 1.8 mg led to statistically significant and clinically relevant improvements in glycated haemoglobin (HbA1C) and body mass index (BMI). Based on these findings, the aim of the present study was to assess the long-term cost-effectiveness of switching from sitagliptin to liraglutide in patients with type 2 diabetes in the UK.

MATERIALS AND METHODS

The IQVIA CORE Diabetes Model Version 8.5+ was used to project costs and clinical outcomes over patients' lifetimes. Baseline cohort characteristics and treatment effects were derived from the LIRA-SWITCH trial. Future costs and clinical benefits were discounted at 3.5% annually. Costs were accounted in pounds sterling (GBP) and expressed in 2016 values. One-way and probabilistic sensitivity analyses were performed.

RESULTS

Model projections showed improved quality-adjusted life expectancy for patients with poorly controlled HbA1c upon switching from sitagliptin to liraglutide, compared with continuing sitagliptin treatment (9.18 vs 9.02 quality-adjusted life years [QALYs]). Treatment switching was associated with increased overall costs (GBP 24737 vs GBP 22362). Higher pharmacy costs were partially offset by reduced diabetes-related complication costs in patients who switched to liraglutide. Switching to liraglutide was associated with an incremental cost-effectiveness ratio of GBP 15423 per QALY gained vs continuing with sitagliptin treatment.

CONCLUSIONS

Switching from sitagliptin 100 mg to liraglutide 1.8 mg in patients with poor glycaemic control was projected to improve clinical outcomes and is likely to be considered cost-effective in the UK setting and, therefore, a good use of limited NHS resources.

Amylin in Alzheimer's disease: Pathological peptide or potential treatment?

Alzheimer's disease (AD) is a neurodegenerative disease for which we currently lack effective treatments or a cure. The pancreatic peptide hormone amylin has recently garnered interest as a potential pharmacological target for the treatment of AD. A number of studies have demonstrated that amylin and amylin analogs like the FDA-approved diabetes drug pramlintide can reduce amyloid burden in the brain and improve cognitive symptoms of AD. However, other data suggest that amylin may have pathological effects in AD due to its propensity to misfold and aggregate under certain conditions. Here, the literature supporting a beneficial versus harmful role of amylin in AD is reviewed. Additionally, several critical gaps in the literature are discussed, such as our limited understanding of the amylin system during aging and in disease states, as well as complexities of amylin receptor signaling and of changing pathophysiology during AD progression that might underlie the seemingly conflicting or contradictory results in the amylin/AD literature. This article is part of the Special Issue entitled 'Metabolic Impairment as Risk Factors for Neurodegenerative Disorders.'

Patient preferences in Italy: health state utilities associated with attributes of weekly injection devices for treatment of type 2 diabetes

OBJECTIVES

Several glucagon-like peptide-1 receptor agonists are administered as weekly injections for treatment of type 2 diabetes (T2D). These medications vary in their injection processes, and a recent study in the UK found that these differences had an impact on patient preference and health state utilities. The purpose of this study was to replicate the UK study in Italy to examine preferences of an Italian patient sample, while allowing for comparison between utilities in the UK and Italy.

MATERIALS AND METHODS

Participants with T2D in Italy valued health states in time trade-off interviews. All health states had the same description of T2D, but differed in description of the treatment process. As in the original UK study, the first health state described an oral treatment regimen, while additional health states added a weekly injection. The injection health states differed in three injection-related attributes: requirements for reconstituting the medication, waiting during medication preparation, and needle handling.

RESULTS

Interviews were completed by 238 patients (58.8% male; mean age = 60.2 years; 118 from Milan, 120 from Rome). The oral treatment health state had a mean (SD) utility of 0.90 (0.10). The injection health states had significantly (p < 0.0001) lower utilities, which ranged from 0.87 (requirements for reconstitution, waiting, and handling) to 0.89 (weekly injection with none of these requirements). Differences in health state utility scores suggest that each administration requirement was associated with a disutility (ie, negative utility difference): -0.006 (reconstitution), -0.006 (needle handling), -0.011 (reconstitution, needle handling), and -0.022 (reconstitution, waiting, needle handling).

CONCLUSION

Disutilities associated with the injection device characteristics were similar to those reported with the UK sample. Results suggest that injection device attributes may be important to some patients with T2D, and it may be useful for clinicians to consider these attributes when choosing medication for patients initiating these weekly treatments.

Health state utilities associated with attributes of weekly injection devices for treatment of type 2 diabetes

Background

Glucagon-like peptide-1 (GLP-1) receptor agonists are often recommended as part of combination therapy for type 2 diabetes when oral medication does not result in sufficient glycemic control. Several GLP-1 receptor agonists are available as weekly injections. These medications vary in their injection delivery systems, and these differences could impact quality of life and treatment preference. The purpose of this study was to estimate utilities associated with attributes of injection delivery systems for weekly GLP-1 therapies.

Methods

Participants with type 2 diabetes in the UK valued health states in time trade-off interviews. The health states (drafted based on literature, device instructions for use, and clinician interviews) had identical descriptions of type 2 diabetes, but differed in description of the treatment process. One health state described oral treatment, while six others described oral treatment plus a weekly injection. The injection health states varied in three aspects of the treatment administration process: requirements for reconstituting the medication (i.e., mixing the medication prior to the injection), waiting during medication preparation, and needle handling. Every participant valued all seven health states.

Results

A total of 209 participants completed interviews (57.4% male; mean age = 60.4y). The mean utility of the oral treatment health state was 0.89. All injection health states had significantly (p < 0.01) lower utilities ranging from 0.86 to 0.88. Differences among health state utilities suggest that each administration requirement had a small but measureable disutility: -0.004 (reconstitution), -0.004 (needle handling), -0.010 (reconstitution, needle handling), and -0.020 (reconstitution, waiting, needle handling).

Conclusions

Findings suggest it is feasible to use the TTO method to quantify preferences among injection treatment processes. It may be useful to incorporate these utility differences into cost-utility models comparing weekly injectable treatments for patients with type 2 diabetes.

Comparative Effectiveness of Rapid-Acting Insulins in Adults with Diabetes

BACKGROUND

Although there are a variety of insulin products and new delivery modalities available, the absence of direct clinical and economic comparisons can make treatment planning and formulary decision making difficult. Direct comparisons between insulin aspart and insulin lispro from a large heterogeneous population are not available.

OBJECTIVE

To assess differences in clinical outcomes, medication adherence, utilization, and total health care costs between aspart and lispro and vial versus pen modalities for administering these short-acting insulin analogs.

METHODS

This retrospective cohort study used administrative claims data from the Humana Research Database to identify people with type 1 or type 2 diabetes and Medicare or commercial insurance (with medical and pharmacy benefits) who newly initiated rapid-acting insulin between January 1, 2008, and December 31, 2013, and were continuously enrolled during the 12-month baseline and 12-month follow-up periods. Generalized linear models were used to assess differences in costs and utilization. Logistic regression models measured the likelihood of having a hypoglycemic event, worsening diabetes complications, or a change in glycated hemoglobin (A1c).

RESULTS

8,189 patients included in the study were grouped by rapid-acting insulin product (aspart, n = 5,364, and lispro, n = 2,566) and modality (vial, n = 6,135, and pen, n = 2,054). There were no significant differences in the percentage of patients with a hypoglycemic event, new or worsening diabetes complications, or change in A1c, and there were no significant differences in adjusted total health care, medical and pharmacy costs, or emergency department visits between any of the product or modality comparisons. There was a significant difference in mean annual inpatient stays between lispro and aspart (adjusted mean = 2.24, 95% CI = 0.73-6.69, and adjusted mean = 2.65, 95% CI = 0.86-7.86, respectively; P < 0.001) and pen and vial cohorts (adjusted mean = 1.74, 95% CI = 0.56-4.99, and adjusted mean = 3.05, 95% CI = 1.01-9.08, respectively; P < 0.001). Adherence was similar for the lispro and aspart cohorts. Adherence was higher in the pen cohort (as measured by medication possession ratio ≥80%) compared with the vial cohort (adjusted odds ratio = 1.29, 95% CI = 1.12-1.50).

CONCLUSIONS

This study provides a comprehensive assessment of outcomes and costs between 2 commonly used rapid-acting insulin products. Overall, there was little differentiation between products, although adherence improved significantly with pen devices. These findings may simplify decisions related to formulary options and choice of therapy.

DISCLOSURES

No outside funding supported this study. Racsa and Ellis are employees of Comprehensive Health Insights, a subsidiary of Humana, and Saverno was employed with Comprehensive Health Insights at the time of this study. Meah is an employee of, and owns stock in, Humana. The authors have no financial disclosures or potential conflicts of interest to report. All authors contributed equally to study concept and design, data interpretation, and manuscript preparation. Racsa collected the data.

Insulin resistance, role of metformin and other non-insulin therapies in pediatric type 1 diabetes

Type 1 diabetes mellitus (T1DM) in youth is a challenging chronic medical condition. Its management should address not only the glycemic control but also insulin resistance and cardiovascular disease risk factors which are increasingly recognized to be present in youth with TID. Current knowledge on the mechanisms of insulin resistance in T1DM is reviewed. The use of adjunctive therapies that are beneficial to achieve adequate glycemic control while mitigating the effects of insulin resistance are discussed with a focus on metformin therapy and an overview of other new pharmacologic agents.