Effects of Sambiloto (Andrographis paniculata) on GLP-1 and DPP-4 Concentrations between Normal and Prediabetic Subjects: A Crossover Study

Background. The extract of Andrographis paniculata (Burm. F.) Wall. Ex. Nees. (sambiloto) (穿心蓮 chuān xīn lián) has been reported to have an antidiabetic effect on mice models and has been used traditionally in the community. The exact mechanism of sambiloto extract in decreasing plasma glucose is unclear, so we investigated the role of sambiloto extract in the incretin pathway in healthy and prediabetic subjects. Methods. This study was a randomized, placebo-controlled, crossover, double-blind trial. It included 38 people who were healthy and 35 people who had prediabetes. All subjects were randomly assigned to receive either the intervention sambiloto extract or a placebo. All subjects were randomly assigned to receive the first intervention for 14 days. There was a washout period between subsequent interventions. The primary outcome was glucagon-like peptide 1 (GLP-1) concentration, and secondary outcomes were fasting insulin, 2-hour postprandial insulin, homeostasis model assessment of insulin resistance (HOMA-IR), fasting blood glucose, 2-hour postprandial blood glucose, dipeptidyl peptidase-4 (DPP-4), and glycated albumin before and after the intervention. Result. After the intervention, GLP-1 concentration significantly increased in prediabetes by 19.6% compared to the placebo ( p = 0.043 ). There were no significant differences in the changes of fasting insulin, 2-hour postprandial insulin, HOMA-IR, fasting blood glucose, 2-hour postprandial blood glucose, DPP-4, and glycated albumin levels after the intervention. Sambiloto extract did not inhibit the DPP-4 enzyme in healthy and prediabetic subjects. Conclusion. Sambiloto extract increased GLP-1 concentration without inhibiting the DPP-4 enzyme in prediabetic subjects. This trial is registered with ClinicalTrials.gov (ID: NCT03455049), registered on 6 March 2018—retrospectively registered (https://clinicaltrials.gov/ct2/show/NCT03455049).

Fluorescence Microscopy-Based Quantitation of GLUT4 Translocation

Postprandial insulin-stimulated glucose uptake into target tissue is crucial for the maintenance of normal blood glucose homeostasis. This step is rate-limited by the number of facilitative glucose transporters type 4 (GLUT4) present in the plasma membrane. Since insulin resistance and impaired GLUT4 translocation are associated with the development of metabolic disorders such as type 2 diabetes, this transporter has become an important target of antidiabetic drug research. The application of screening approaches that are based on the analysis of GLUT4 translocation to the plasma membrane to identify substances with insulinomimetic properties has gained global research interest in recent years. Here, we review methods that have been implemented to quantitate the translocation of GLUT4 to the plasma membrane. These methods can be broadly divided into two sections: microscopy-based technologies (e.g., immunoelectron, confocal or total internal reflection fluorescence microscopy) and biochemical and spectrometric approaches (e.g., membrane fractionation, photoaffinity labeling or flow cytometry). In this review, we discuss the most relevant approaches applied to GLUT4 thus far, highlighting the advantages and disadvantages of these approaches, and we provide a critical discussion and outlook into new methodological opportunities.

Insulin Clearance in Obesity and Type 2 Diabetes

Plasma insulin clearance is an important determinant of plasma insulin concentration. In this review, we provide an overview of the factors that regulate insulin removal from plasma and discuss the interrelationships among plasma insulin clearance, excess adiposity, insulin sensitivity, and type 2 diabetes (T2D). We conclude with the perspective that the commonly observed lower insulin clearance rate in people with obesity, compared with lean people, is not a compensatory response to insulin resistance but occurs because insulin sensitivity and insulin clearance are mechanistically, directly linked. Furthermore, insulin clearance decreases postprandially because of the marked increase in insulin delivery to tissues that clear insulin. The commonly observed high postprandial insulin clearance in people with obesity and T2D likely results from the relatively low insulin secretion rate, not an impaired adaptation of tissues that clear insulin.

A case of spontaneous hypoglycemia

We describe a case of systemic lupus erythematosus with POEMS syndrome presenting as spontaneous hypoglycemia. A 58-year-old female suffered repeated episodes of hypoglycemia. During thesehypoglycemic episodes, her postprandial insulin level was inappropriately high. Further blood tests revealed the presence of antinuclear antibodies, anti-double-stranded DNA antibodies,low C4level.Altered albumin-globulin ratio,monoclonal gammopathy (IgG LAMBDA), polyneuropathy and organomegaly lead to suspicion of concurrent presence of POEMS syndrome.Bone marrow examination revealed plasma cell dyscrasia and plasmacytoma in trephine biopsy confirmed the diagnosis.Here, we emphasize on autoimmune cause of hypoglycemia. BIRDEM Med J 2022; 12(1): 70-73

Effects of neuromuscular electrical stimulation on energy expenditure and postprandial metabolism in healthy men

It is unclear whether NeuroMuscular Electrical Stimulation (NMES) has meaningful metabolic effects when users have the opportunity to self-select the intensity to one that can be comfortably tolerated. Nine healthy men aged 28 ± 9 y (mean ± SD) with a body mass index 22.3 ± 2.3 kg/m2 completed 3 trials involving a 2-h oral glucose tolerance test whilst, in a randomized counterbalanced order, (1) sitting motionless (SIT), (2) standing motionless (STAND); and (3) sitting motionless with NMES of quadriceps and calves at a self-selected tolerable intensity. Mean (95% confidence interval [CI]) total energy expenditure was greater in the NMES trial (221 [180–262] kcal/2 h) and STAND trial (178 [164–191] kcal/2 h) than during SIT (159 [150–167] kcal/2 h) (both, p < 0.05). This was primarily driven by an increase in carbohydrate oxidation in the NMES and STAND trials compared to SIT (p < 0.05). Postprandial insulin iAUC was lower in both NMES and STAND compared to SIT (16.4 [7.7–25.1], 17 [7–27] & 22.6 [10.8–34.4] nmol·120 min/L, respectively; both, p < 0.05). Compared with sitting, both NMES and STAND increased energy expenditure and whole-body carbohydrate oxidation and reduced postprandial insulin concentrations in healthy men, with more-pronounced effects seen with NMES. Self-selected NMES is a potential strategy to improve metabolic health. This trial is registered at ClinicalTrials.gov (ID: NCT04389736). Novelty • NMES at a comfortable intensity enhances energy expenditure & carbohydrate oxidation and reduces postprandial insulinemia. • Thus, self-selected NMES represents a potential strategy to improve metabolic health.

AMH Is a Good Predictor of Metabolic Risk in Women with PCOS: A Cross-Sectional Study

Objective. The relationship between metabolic risk and ovarian function is ambiguous. This retrospective study analyzed the medical records of 461 PCOS patients collected between January 2019 and June 2020 to investigate the relationship between serum anti-Müllerian hormone (AMH) and parameters of metabolic risk in the population with polycystic ovary syndrome (PCOS). Methods. A total of 461 PCOS patients aged 20–40 years were included and stratified into four groups according to the AMH level. The association between AMH and the parameters related to metabolic risk in these groups was compared, and the discrepancies were further explored. Binary logistic regression was performed to examine the risk factors of HOMA-IR. The values of AMH that best predicted the risk of HOMA-IR were also analyzed by ROC curves. Results. AMH was negatively associated with HOMA-IR (odds ratio (OR) −0.279, 95% confidence interval (CI) −0.36 to −0.20), fasting insulin (OR −0.282, 95% CI −0.36 to −0.20), 1-hour postprandial insulin (OR −0.184, 95% CI −0.28 to −0.11), 2-hour postprandial insulin (−0.180, 95%CI −0.28 to −0.11), 3-hour postprandial insulin (OR −0.198, 95% CI –0.30 to −0.13), waist-hip ratio (OR −0.235, 95% CI −0.31 to −0.14), and body mass index (OR −0.350, 95% CI −0.43 to −0.27). There was no statistically significant relationship between blood pressure, serum glucose profile, or lipid levels and AMH. Binary logistic regression showed that AMH protected against the occurrence of PCOS patients (OR: 0.835, 0.776, and 0.898). For the prediction of HOMA-IR, AMH had an AUC-ROC of 0.704 (95% CI 0.652–0.755) with a cutoff value of 7.81 mmol/L, a sensitivity of 70.3%, and a specificity of 70.1%. Conclusions. Higher AMH levels were significantly associated with a lower insulin profile and might be a useful predictor for HOMA-IR in PCOS patients.

Plasma Branched-Chain Amino Acids Are Associated With Greater Fasting and Postprandial Insulin Secretion in Non-diabetic Chinese Adults

Background: Plasma branched-chain amino acids (BCAA) are consistently elevated in subjects with obesity and type 2 diabetes (T2DM) and correlate with insulin resistance. The association of BCAA with insulin secretion and clearance rates has not been adequately described.Objective: To evaluate the relationships between fasting and postprandial plasma BCAA, insulin secretion and insulin clearance.Design: Ninety-five non-diabetic Chinese subjects (43 females) underwent a mixed-meal tolerance test; blood biomarkers including BCAAs (leucine, isoleucine, valine) were measured for 6 h. Fasting and postprandial insulin secretion rates (ISR) and insulin clearance were determined by oral minimal modeling of glucose and C-peptide.Results: Fasting and postprandial plasma BCAA correlated strongly with each other (ρ = 0.796, P &lt; 0.001), and both were positively associated with basal ISR (ρ = 0.45/0.36, P &lt; 0.001), total postprandial ISR AUC (ρ = 0.37/0.45, P &lt; 0.001), and negatively with insulin clearance (ρ = −0.29/−0.29, P &lt; 0.01), after adjusting for sex and body mass index. These relationships largely persisted after adjusting further for insulin resistance and postprandial glucose. Compared with subjects in the middle and lowest tertiles for fasting or postprandial plasma BCAA, subjects in the highest tertile had significantly greater postprandial glucose (by 7–10%) and insulin (by 74–98%) concentrations, basal ISRs (by 34–53%), postprandial ISR AUCs (by 41–49%), and lower insulin clearance rates (by 17–22%) (all P &lt; 0.05).Conclusions: Fasting and postprandial plasma BCAA levels are associated with greater fasting and postprandial insulin secretion and reduced insulin clearance in healthy Chinese subjects. These observations potentially highlight an additional layer of involvement of BCAA in the regulation of glucose homeostasis.

Effects of endogenous GIP in patients with type 2 diabetes

Objective: The insulinotropic effect of exogenous, intravenously infused glucose-dependent insulinotropic polypeptide (GIP) is impaired in patients with type 2 diabetes. We evaluated the effects of endogenous GIP in relation to glucose and bone metabolism in patients with type 2 diabetes using a selective GIP receptor antagonist and hypothesized that the effects of endogenous GIP were preserved. Design: A randomized, double-blinded, placebo-controlled, crossover study. Methods: Ten patients with overweight/obesity and type 2 diabetes (mean±SD; HbA1c 52±11 mmol/mol; BMI 32.5±4.8 kg/m2) were included. We infused a selective GIP receptor antagonist, GIP(3-30)NH2 (1,200 pmol × kg-1 × min-1), or placebo (saline) during two separate, 230-minute, standardized, liquid mixed meal tests followed by an ad libitum meal. Subcutaneous adipose tissue biopsies were analyzed. Results: Compared with placebo, GIP(3-30)NH2 reduced postprandial insulin secretion (Δbaseline-subtracted area under the curve (bsAUC)C-peptide%±SEM; -14±6%, p=0.021) and peak glucagon (Δ%±SEM; -11±6%, p=0.046), but had no effect on plasma glucose (p=0.692). Suppression of bone resorption (assessed by circulating carboxy-terminal collagen crosslinks (CTX)) was impaired during GIP(3-30)NH2 infusion compared with placebo (ΔbsAUCCTX;±SEM; -4.9±2 ng/ml × min, p=0.005) corresponding to a ~50% reduction. Compared with placebo, GIP(3-30)NH2 did not affect plasma lipids, ad libitum meal consumption or adipose tissue triglyceride content. Conclusions: Using a selective GIP receptor antagonist during a meal, we show that endogenous GIP increases postprandial insulin secretion with little effect on postprandial glycemia but is important for postprandial bone homeostasis in patients with type 2 diabetes.