The effects of GLP-1 based therapies on postprandial haemodynamics: Two randomised, placebo-controlled trials in overweight type 2 diabetes patients

Meta-analysis on GLP-1 mediated modulation of autophagy in islet β-cells: Prospectus for improved wound healing in type 2 diabetes

Type 2 diabetes mellitus refers to a significantly challenging health disease due to its high prevalence and risk of other chronic diseases across the world. Notably, GLP-1 has been recognized to enhance the treatment of T2DM, along with this, GLP-1 is also involved in autophagy modulation. However, ineffectiveness of few analogue types can limit the efficacy of this treatment. This study particularly aims to elucidate the influence of GLP-1 receptor analogues on wound infection and patients with type 2 diabetes. To conduct the meta-analysis, an expansive literature survey was conducted to unveil the studies and research conducted on T2DM patients that revealed whether the adoption of any GLP-1 analogue in the form of specific interventions impacts the type 2 diabetes mellitus. The literature was searched using multiple search terms, screened and data were extracted to conduct the meta-analysis and it was conducted using metabin function of R package meta. A total of 800 patients consisting of the both intervention and control groups were employed to carry out the meta-analysis to analyse and evaluate the impact of GLP-1 mediated modulation to improve wound healing in the T2DM patients. The results revealed that GLP-1 mediated modulation considering one type of analogue was an effective intervention to patients suffering from T2DM. The variations in these results depicted insignificant outcomes with the values (risk ratio [RR]: 1.03, 95% confidence interval [CI]: 0.90-1.18, p > 0.05) and enlightened the fact that adopting different GLP-1 analogues may significantly improve the efficacy of wound healing in T2DM patients. Hence, interventions of GLP-1 mediated modulation must be utilized in the clinical practice to reduce the incidence of T2DM patients.

The effect of SGLT2 inhibitors, GLP1 agonists, and their sequential combination on cardiometabolic parameters: A randomized, prospective, intervention study

BACKGROUND

Pulse wave velocity (PWV) and augmentation index (AIx) are indices used to assess arterial stiffness. We aim to compare the effect of empagliflozin, liraglutide and their sequential combination on arterial stiffness indices in patients with type 2 diabetes (T2D).

METHODS

This was a randomized single blind study evaluating the effect of empagliflozin vs liraglutide in adult patients with T2D. Patients were randomized to liraglutide titrated gradually to 1.8 mg or empagliflozin 25 mg in 1:1 ratio. Three months later empagliflozin was added to the liraglutide group, and liraglutide was added to the empagliflozin group. Patients were assessed with non-invasive tests for arterial stiffness (i.e., carotid-femoral PWV and AIx of aortic pressure) at baseline, 3-month and 9-month visits (final visit was extended for 3 months from the initial design due to Covid 19 pandemic). The primary outcome was the between-group difference of PWV change (ΔPWV) and ΔAIx at 3 months. Secondary outcomes included the between-group difference of ΔPWV and ΔAIx at 9 months, as well as the ΔPWV and ΔAIx between baseline and 9-month visit when total study population was assessed.

RESULTS

A total of 62 patients with T2D (30 started liraglutide; 32 empagliflozin, mean age 63 years, 25 % with established cardiovascular disease) participated in the study. We failed to show any significant between-group differences of ΔPWV and ΔΑΙx at 3 and 9 months, as well as between-group difference of ΔPWV and ΔAIx for the total study population between baseline and 9-month visit. In contrast, systemic vascular resistance and lipoprotein(a) levels improved, showing better results with liraglutide than empagliflozin. Favorable effects were also observed on body weight, body mass index, body and visceral fat, blood pressure, HbA1c, and uric acid levels.

CONCLUSION

No evidence of a favorable change in arterial stiffness indices was seen with empagliflozin or liraglutide or their combination in this study. Well-designed powerful studies are needed to address any potential effects on arterial stiffness in selected populations.

Acarbose for Postprandial Hypotension With Glucose Metabolism Disorders: A Systematic Review and Meta-Analysis

Background: Postprandial hypotension (PPH) is an independent predictive factor of all-cause mortality in older people. Drug management has not achieved a satisfactory effect yet. In recent years, many studies have found that acarbose may be effective in the treatment of PPH with glucose metabolism disorders.

Objective: To assess the efficacy and safety of acarbose on PPH with glucose metabolism disorders.

Methods: PubMed (MEDLINE), Cochrane, EMBASE, Web of Science, Clinical Trials, and relevant Chinese databases were searched from inception to October 1, 2020. Randomized controlled studies of acarbose in the treatment of PPH with glucose metabolism disorders were included. Review Manager 5.3 software was used for quality evaluation and meta-analysis. GRADEpro GDT software was used to GRADE the evidence for the research objectives.

Results: A total of 4 randomized controlled studies including 202 participants were identified after screening. The meta-analysis showed that acarbose significantly attenuated the decrease in postprandial systolic blood pressure [weighted mean difference (MD): −9.84, 95% CI: −13.34 to −6.33], diastolic blood pressure (MD: −6.86, 95% CI: −12.89 to −0.83), and mean arterial pressure (MD: −8.10, 95% CI: −12.40 to −3.49) compared with the control group. One study reported a case of adverse reactions that included mild abdominal distension in the acarbose group (4.8%, 1/21). No adverse reactions were reported in the other three studies.

Conclusion: Acarbose may attenuate the decrease in postprandial blood pressure and avoid the occurrence of PPH in patients with PPH and abnormal glucose metabolism disorders. More clinical trials are needed to make a clear conclusion.

Registration: PROSPERO CRD42020171335.

Effects of dipeptidyl peptidase-4 inhibitor linagliptin versus sulphonylurea glimepiride on systemic haemodynamics in overweight patients with type 2 diabetes: A secondary analysis of an 8-week, randomized, controlled, double-blind trial

AIM

To determine the glucose-independent effect of the dipeptidyl peptidase-4 (DPP-4) inhibitor linagliptin versus the sulphonylurea glimepiride on systemic haemodynamics in the fasting and postprandial state in patients with type 2 diabetes (T2D).

MATERIALS AND METHODS

In this prespecified secondary analysis of a phase IV, double-blind trial, 46 metformin-treated, overweight patients with T2D were included and randomly assigned (1:1) to once-daily linagliptin (5 mg) or glimepiride (1 mg) for 8 weeks. In a sub-study involving 26 patients, systemic haemodynamics were also assessed following a standardized liquid meal (Nutridrink Yoghurt style). Systemic haemodynamics (oscillometric device and finger photoplethysmography), arterial stiffness (applanation tonometry) and cardiac sympathovagal balance (heart rate variability [HRV]) were measured in the fasting state and repetitively following the meal. Ewing tests were performed in the fasting state.

RESULTS

From baseline to week 8, linagliptin compared with glimepiride did not affect systemic haemodynamics, arterial stiffness or HRV in the fasting state. Linagliptin increased parasympathetic nervous activity, as measured by the Valsalva manoeuvre (P = .021) and deep breathing test (P = .027) compared with glimepiride. Postprandially, systolic blood pressure (SBP) dropped an average of 7.6 ± 1.6 mmHg. Linagliptin reduced this decrease to 0.7 ± 2.3 mmHg, which was significant to glimepiride (P = .010).

CONCLUSIONS

When compared with glimepiride, linagliptin does not affect fasting blood pressure. However, linagliptin blunted the postprandial drop in SBP, which could benefit patients with postprandial hypotension.

The Effect of DPP-4i on Endothelial Function and Arterial Stiffness in Patients with Type 2 Diabetes: A Systematic Review of Randomized Placebo-controlled Trials

We systematically reviewed the literature regarding the impact of dipeptidyl peptidase-4 inhibitors (DPP-4i) on vascular function, including endothelial function and arterial stiffness, as predictors of atherosclerosis progression and cardiovascular disease in patients with type 2 diabetes mellitus (T2DM). We searched PubMed in order to identify clinical trials that investigated the effect of DPP-4i on vascular function in patients with T2DM when compared with placebo. Although 168 articles were initially found, only 6 studies (total 324 patients) investigated the effect of DPP-4i in comparison with placebo, specifically linagliptin and sitagliptin, and satisfied the inclusion criteria. There are scarce data to indicate that linagliptin may enhance endothelial function and exert a slight beneficial effect on arterial wall properties. Sitagliptin seems to have a neutral effect on these variables. Further trials are needed to elucidate the topic. The standards of reporting were in accordance with the PRISMA guidelines.

Effects of sitagliptin on gastric emptying of, and the glycaemic and blood pressure responses to, a carbohydrate meal in type 2 diabetes

AIMS

To determine the effects of the dipeptidyl peptidase-4 inhibitor, sitagliptin, on gastric emptying (GE) of a high-carbohydrate meal and associated glycaemic and blood pressure (BP) responses in type 2 diabetes mellitus (T2DM).

MATERIALS AND METHODS

Fourteen patients with T2DM (nine men, five women; age 67.8 ± 1.5 years; body mass index 31.2 ± 0.9 kg/m² ; T2DM duration: 4.2 ± 0.9 years; glycated haemoglobin: 46 ± 1.8 mmol/mol [6.4% ± 0.2%]), managed by diet and/or metformin, underwent concurrent measurements of GE, BP and plasma glucose for 240 minutes after ingestion of a radiolabelled mashed potato meal after receiving sitagliptin (100 mg) or placebo in randomized, double-blind, crossover fashion on 2 consecutive days.

RESULTS

Sitagliptin reduced postprandial plasma glucose (P < .005) without affecting GE (P = .88). The magnitude of the glucose-lowering effect (change in incremental area under the curve^{0-240 min} from placebo to sitagliptin) was related to GE (kcal/min) on placebo (r = 0.68, P = .008) There was a comparable fall in systolic BP (P = .80) following the meal, with no difference between the 2 days.

CONCLUSIONS

In T2DM, while sitagliptin has no effect on either GE or postprandial BP, its ability to lower postprandial glucose are dependent on the basal rate of GE.

DPP-4 Inhibitors as Potential Candidates for Antihypertensive Therapy: Improving Vascular Inflammation and Assisting the Action of Traditional Antihypertensive Drugs

Dipeptidyl peptidase-4 (DPP-4) is an important protease that is widely expressed on the surface of human cells and plays a key role in immune-regulation, inflammation, oxidative stress, cell adhesion, and apoptosis by targeting different substrates. DPP-4 inhibitors (DPP-4i) are commonly used as hypoglycemic agents. However, in addition to their hypoglycemic effect, DPP-4i have also shown potent activities in the cardiovascular system, particularly in the regulation of blood pressure (BP). Previous studies have shown that the regulatory actions of DPP-4i in controlling BP are complex and that the mechanisms involved include the functional activities of the nerves, kidneys, hormones, blood vessels, and insulin. Recent work has also shown that inflammation is closely associated with the elevation of BP, and that the inhibition of DPP-4 can reduce BP by regulating the function of the immune system, by reducing inflammatory reactions and by improving oxidative stress. In this review, we describe the potential anti-hypertensive effects of DPP-4i and discuss potential new anti-hypertensive therapies. Our analysis indicated that DPP-4i treatment has a mild anti-hypertensive effect as a monotherapy and causes a significant reduction in BP when used in combined treatments. However, the combination of DPP-4i with high-dose angiotensin converting enzyme inhibitors (ACEI) can lead to increased BP. We suggest that DPP-4i improves vascular endothelial function in hypertensive patients by suppressing inflammatory responses and by alleviating oxidative stress. In addition, DPP-4i can also regulate BP by activating the sympathetic nervous system, interfering with the renin angiotensin aldosterone system (RAAS), regulating Na/H₂O metabolism, and attenuating insulin resistance (IR).

The Origin and Understanding of the Incretin Concept

Gastrointestinal hormones that stimulate insulin secretion at physiological concentrations are incretins. This concept has recently attracted considerable attention in the wake of drugs developed from the gut hormone GLP-1 (glucagon-like peptide-1) for diabetes therapy. But the renewed enthusiasm has also restricted the concept to just two hormones, GLP-1 and GIP (glucose-dependent insulinotropic polypeptide). The purpose of the present overview is two-fold: First to tell that the incretin concept is far from new. It has a more than a century long history full of ups and downs. Second, that the incretin concept may now have become too narrow. Thus, it is likely that incretin comprises additional gastrointestinal hormones, which interact with GIP and GLP-1 during normal meals containing protein, fat and complex carbohydrates (and not just pure glucose). Such broader incretin concept may stimulate development of novel gut hormone-derived drugs.

Lixisenatide Versus Insulin Glulisine on Fasting and Postbreakfast Systemic Hemodynamics in Type 2 Diabetes Mellitus Patients

The prolonged treatment effects of a short-acting GLP-1RA (glucagon-like peptide-1 receptor agonist), such as lixisenatide, on fasting and postprandial systemic hemodynamics in type 2 diabetes mellitus patients are unknown. In this secondary analysis, we included 34 overweight insulin glargine-treated type 2 diabetes mellitus patients (mean±SD age, 62±7 years; HbA_1c, 8.0±0.9%; systolic blood pressure [BP], 133.9±16.1 mm Hg; diastolic BP, 75.4±8.39 mm Hg) that were randomized to once-daily lixisenatide 20 μg or once-daily titrated insulin glulisine for 8 weeks. Systemic hemodynamics (oscillometric device and finger photoplethysmography), arterial stiffness (applanation tonometry), and cardiac sympathovagal balance (heart rate variability) were measured in the fasting state and repetitively (up to minute 175) after a standardized mixed breakfast. Acetaminophen was given orally to estimate gastric emptying rate. Lixisenatide did not affect fasting systemic hemodynamics compared with insulin glulisine from baseline to week 8. Postbreakfast overall, lixisenatide compared with insulin glulisine tended to increase systolic BP by 5.2±2.9 mm Hg (P=0.087) and increased diastolic BP by 5.4±1.4 mm Hg (P<0.001), with respective maximal differences of +10.2±3.7 mm Hg (P=0.007) and +7.2±1.5 mm Hg (P<0.001). Lixisenatide increased systemic vascular resistance (P<0.001) and arterial stiffness (P=0.007). No between-group differences in overall postbreakfast heart rate, cardiac output, or cardiac sympathovagal balance, and circulating catecholamines, angiotensin II, or aldosterone were observed. Both treatments lowered HbA_1c similarly, whereas lixisenatide achieved greater reductions in postbreakfast plasma glucose excursions. Lixisenatide slowed gastric emptying rate, which statistically explained changes in postbreakfast BP. Lixisenatide compared with once-daily titrated insulin glulisine for 8 weeks does not affect fasting but increases postbreakfast BP in insulin glargine-treated type 2 diabetes mellitus patients. This effect could, at least in part, be explained by reduced passage rate of nutrients and water and activation of the gastrovascular reflex.

Renal Hyperfiltration in Adolescents with Type 2 Diabetes: Physiology, Sex Differences, and Implications for Diabetic Kidney Disease

PURPOSE OF REVIEW

Compared to adult-onset type 2 diabetes (T2D), youth with T2D have a more aggressive phenotype with greater insulin resistance (IR), more rapid β cell decline, and higher prevalence of diabetic kidney disease (DKD).

RECENT FINDINGS

Hyperfiltration is common in youth with T2D and predicts progressive DKD. Hyperfiltration is a consequence of early changes in intrarenal hemodynamic function, including increased renal plasma flow (RPF) and glomerular pressure. Girls with T2D are disproportionally affected by DKD, with a 3-fold greater risk of developing hyperfiltration over 5 years compared to boys. Despite the high prevalence and gravity of DKD in youth-onset T2D, widely effective therapeutic options are lacking. In this review, we focus on pathophysiology underlying early DKD in T2D and sex differences and summarize promising novel medical therapies and bariatric surgery.

Effects of 6-month treatment with the glucagon like peptide-1 analogue liraglutide on arterial stiffness, left ventricular myocardial deformation and oxidative stress in subjects with newly diagnosed type 2 diabetes

Background

Incretin-based therapies are used in the treatment of type 2 diabetes mellitus (T2DM) and obesity. We investigated the changes in arterial stiffness and left ventricular (LV) myocardial deformation after 6-month treatment with the GLP-1 analogue liraglutide in subjects with newly diagnosed T2DM.

Methods

We randomized 60 patients with newly diagnosed and treatment-naive T2DM to receive either liraglutide (n = 30) or metformin (n = 30) for 6 months. We measured at baseline and after 6-month treatment: (a) carotid-femoral pulse wave velocity (PWV) (b) LV longitudinal strain (GLS), and strain rate (GLSR), peak twisting (pTw), peak twisting velocity (pTwVel) and peak untwisting velocity (pUtwVel) using speckle tracking echocardiography. LV untwisting was calculated as the percentage difference between peak twisting and untwisting at MVO (%dpTw–Utw_MVO), at peak (%dpTw–Utw_PEF) and end of early LV diastolic filling (%dpTw–Utw_EDF) (c) Flow mediated dilatation (FMD) of the brachial artery and percentage difference of FMD (FMD%) (d) malondialdehyde (MDA), protein carbonyls (PCs) and NT-proBNP.

Results

After 6-months treatment, subjects that received liraglutide presented with a reduced PWV (11.8 ± 2.5 vs. 10.3 ± 3.3 m/s), MDA (0.92 [0.45–2.45] vs. 0.68 [0.43–2.08] nM/L) and NT-proBNP (p < 0.05) in parallel with an increase in GLS (− 15.4 ± 3 vs. − 16.6 ± 2.7), GLSR (0.77 ± 0.2 vs. 0.89 ± 0.2), pUtwVel (− 97 ± 49 vs. − 112 ± 52°, p < 0.05), %dpTw–Utw_MVO (31 ± 10 vs. 40 ± 14), %dpTw–Utw_PEF (43 ± 19 vs. 53 ± 22) and FMD% (8.9 ± 3 vs. 13.2 ± 6, p < 0.01). There were no statistically significant differences of the measured markers in subjects that received metformin except for an improvement in FMD. In all subjects, PCs levels at baseline were negatively related to the difference of GLS (r = − 0.53) post-treatment and the difference of MDA was associated with the difference of PWV (r = 0.52) (p < 0.05 for all associations) after 6-month treatment.

Conclusions

Six-month treatment with liraglutide improves arterial stiffness, LV myocardial strain, LV twisting and untwisting and NT-proBNP by reducing oxidative stress in subjects with newly diagnosed T2DM.

ClinicalTrials.gov Identifier NCT03010683

Postprandial renal haemodynamic effect of lixisenatide vs once-daily insulin-glulisine in patients with type 2 diabetes on insulin-glargine: An 8-week, randomised, open-label trial

AIM

To determine whether lixisenatide, a prandial short-acting glucagon-like peptide receptor agonist (GLP-1RA), ameliorates postprandial glomerular hyperfiltration in patients with type 2 diabetes mellitus (T2DM) compared with insulin-glulisine (iGlu).

METHODS

Postprandial renal haemodynamic effects of 8-week treatment with lixisenatide 20 µg vs once-daily titrated iGlu were measured in 35 overweight patients with T2DM inadequately controlled on insulin-glargine, with or without metformin [mean ± SD age 62 ± 7 years, HbA1c 8.0% ± 0.9%, estimated glomerular filtration rate (GFR) 85 ± 12 mL/min/1.73 m² , median (IQR) urinary albumin/creatinine ratio 1.5 (0.9-3.0) mg/mmol]. After a standardised breakfast, GFR (primary endpoint) and effective renal plasma flow (ERPF) were determined by inulin and para-aminohippuric acid renal clearance, respectively, based on timed urine sampling. Intrarenal haemodynamic functions were estimated using Gomez equations.

RESULTS

Compared with iGlu, lixisenatide did not affect GFR [+0.1 mL/min/1.73 m² (95% CI -9 to 9)], ERPF [-17 mL/min/1.73 m² (-61 to 26)], other (intra-)renal haemodynamics or renal damage markers, but increased fractional sodium excretion [+0.25% (0.09-0.41)] and urinary pH [+0.7 (0.3-1.2)]. Plasma renin, angiotensin-II and aldosterone were unchanged. Lixisenatide and iGlu reduced HbA1c similarly, by 0.8% ± 0.1% and 0.6% ± 0.1%, respectively, while postprandial glucose was lower with lixisenatide (P = .002). Compared with iGlu, lixisenatide reduced bodyweight [-1.4 kg (-2.5 to -0.2)] and increased postprandial mean arterial pressure [+9 mm Hg (4-14)].

CONCLUSION

Eight-week lixisenatide treatment does not affect postprandial (intra-)renal haemodynamics compared with iGlu when added to insulin-glargine in patients with T2DM without overt nephropathy. Prolonged lixisenatide treatment has a sustained natriuretic effect, which is in contrast to previous reports on long-acting GLP-1RA, reduces body weight and increases postprandial blood pressure compared with iGlu.

TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT02276196.

α-Glucosidase inhibitor miglitol attenuates glucose fluctuation, heart rate variability and sympathetic activity in patients with type 2 diabetes and acute coronary syndrome: a multicenter randomized controlled (MACS) study

Background

Little is known about clinical associations between glucose fluctuations including hypoglycemia, heart rate variability (HRV), and the activity of the sympathetic nervous system (SNS) in patients with acute phase of acute coronary syndrome (ACS). This pilot study aimed to evaluate the short-term effects of glucose fluctuations on HRV and SNS activity in type 2 diabetes mellitus (T2DM) patients with recent ACS. We also examined the effect of suppressing glucose fluctuations with miglitol on these variables.

Methods

This prospective, randomized, open-label, blinded-endpoint, multicenter, parallel-group comparative study included 39 T2DM patients with recent ACS, who were randomly assigned to either a miglitol group (n = 19) or a control group (n = 20). After initial 24-h Holter electrocardiogram (ECG) (Day 1), miglitol was commenced and another 24-h Holter ECG (Day 2) was recorded. In addition, continuous glucose monitoring (CGM) was performed throughout the Holter ECG.

Results

Although frequent episodes of subclinical hypoglycemia (≤4.44 mmo/L) during CGM were observed on Day 1 in the both groups (35% of patients in the control group and 31% in the miglitol group), glucose fluctuations were decreased and the minimum glucose level was increased with substantial reduction in the episodes of subclinical hypoglycemia to 7.7% in the miglitol group on Day 2. Holter ECG showed that the mean and maximum heart rate and mean LF/HF were increased on Day 2 in the control group, and these increases were attenuated by miglitol. When divided 24-h time periods into day-time (0700–1800 h), night-time (1800–0000 h), and bed-time (0000–0700 h), we found increased SNS activity during day-time, increased maximum heart rate during night-time, and glucose fluctuations during bed-time, which were attenuated by miglitol treatment.

Conclusions

In T2DM patients with recent ACS, glucose fluctuations with subclinical hypoglycemia were associated with alterations of HRV and SNS activity, which were mitigated by miglitol, suggesting that these pathological relationships may be a residual therapeutic target in such patients.

Trial registration Unique Trial Number, UMIN000005874 (https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000006929)

Electronic supplementary material

The online version of this article (doi:10.1186/s12933-017-0571-1) contains supplementary material, which is available to authorized users.