A review of stress-induced hyperglycaemia in the context of acute ischaemic stroke: Definition, underlying mechanisms, and the status of insulin therapy

The transient elevation of blood glucose produced following acute ischaemic stroke (AIS) has been described as stress-induced hyperglycaemia (SIH). SIH is common even in patients with AIS who have no previous diagnosis of diabetes mellitus. Elevated blood glucose levels during admission and hospitalization are strongly associated with enlarged infarct size and adverse prognosis in AIS patients. However, insulin-intensive glucose control therapy defined by admission blood glucose for SIH has not achieved the desired results, and new treatment ideas are urgently required. First, we explore the various definitions of SIH in the context of AIS and their predictive value in adverse outcomes. Then, we briefly discuss the mechanisms by which SIH arises, describing the dual effects of elevated glucose levels on the central nervous system. Finally, although preclinical studies support lowering blood glucose levels using insulin, the clinical outcomes of intensive glucose control are not promising. We discuss the reasons for this phenomenon.

Identifying adverse drug reactions from patient reviews on social media using natural language processing

Drugs have the potential of causing adverse reactions or side effects and prior knowledge of these reactions can help prevent hospitalizations and premature deaths. Public databases of common adverse drug reactions (ADRs) depend on individual reports from drug manufacturers and health professionals. However, this passive approach to ADR surveillance has been shown to suffer from severe under-reporting. Social media, such as online health forums where patients across the globe willingly share their drug intake experience, is a viable and rich source for detecting unreported ADRs. In this paper, we design an ADR Detection Framework (ADF) using Natural Language Processing techniques to identify ADRs in drug reviews mined from social media. We demonstrate the applicability of ADF in the domain of Diabetes by identifying ADRs associated with diabetes drugs using data extracted from three online patient-based health forums: askapatient.com, webmd.com, and iodine.com. Next, we analyze and visualize the ADRs identified and present valuable insights including prevalent and less prevalent ADRs, age and gender differences in ADRs detected, as well as the previously unknown ADRs detected by our framework. Our work could promote active (real-time) ADR surveillance and also advance pharmacovigilance research.

A combination of metformin and insulin improve cardiovascular and cerebrovascular risk factors in individuals with type 1 diabetes mellitus

BACKGROUND

This study aims to further clarify whether the addition of metformin to insulin treatment improve cardiovascular and cerebrovascular risk factors in individuals with T1DM.

METHODS

Electronic databases were searched for randomized controlled trials in which the efficacy and safety of metformin were compared with those of a placebo for risk factors of cardiovascular and cerebrovascular disease among individuals with T1DM, and a meta-analysis was conducted.

RESULTS

Thirteen cardiovascular studies were identified. In the metformin group, mean carotid intimal media thickness was significantly reduced by 0.03 mm, ascending aortic pulse wave velocity by 6.3 m/s, descending aortic wall shear stress by 1.77 dyn/cm² (P = 0.02), insulin daily dose by 0.05 U/kg/d, body weight by 2.27 kg, fat-free mass by 1.32 kg, body mass index by 0.58 kg/m², hip circumference by 0.29 m, and low-density lipoprotein by 0.16 mmol/L, all above are P < 0.05. In the metformin group, flow-mediated dilation was increased by 1.29 %, glucose infusion rate/insulin by 18.22 mg/(kg⋅min)/μIU/μL, and waist-to-hip ratio by 0.02, all above are P < 0.00001. The metformin group showed no differences in blood pressure, reactive hyperemia index, waist circumference, triglyceride, total cholesterol, high-density lipoprotein cholesterol, or body mass index Z score. For cerebrovascular studies were identified. But none of them had a risk factor assessment.

CONCLUSIONS

Metformin can ameliorate cardiovascular and cerebrovascular risk factors through non-hypoglycemic multiple pathways in individuals with T1DM.

Metformin use is associated with low risk of case fatality and disability rates in first-ever stroke patients with type 2 diabetes

Background:

To assess the effectiveness of metformin treatment on long-term outcomes in first-ever stroke patients with type 2 diabetes mellitus (T2DM) in China.

Methods:

From August to September 2019, all patients with first-ever stroke and T2DM from 232 hospitals in China Mainland were included. The enrolled patients were divided into two groups: the metformin treatment (MT) and the no-metformin treatment (No-MT) groups. All discharged patients would receive a telephone follow-up at 12-month after admission.

Results:

In total, 7587 first-ever stroke patients with T2DM [age: median (IQR) = 66 (57–73) years; 57.35% male] were recruited. Out of those 7587 included patients, 3593 (47.36%) received MT. The in-hospital case fatality rate was lower in the MT group than the No-MT group [MT group versus No-MT group: 1.09% versus 2.30%; absolute difference = −1.75% (95% CI = −2.15 to −1.17%); OR = 0.63 (95% CI = 0.47 to 0.84)]. The 12-month case fatality rate was lower in the MT group than the No-MT group [4.72% versus 8.05%; absolute difference = −4.05% (95% CI = −5.58 to −2.41); OR = 0.69 (95% CI = 0.50 to 0.88)]. The 12-month disability rate was also lower in the MT group than the No-MT group [14.74% versus 19.41%; absolute difference = −5.70% (95% CI = −7.25 to −3.22); OR = 0.83 (95% CI = 0.70 to 0.95)]. Furthermore, the recurrence rate did not differ significantly between the MT and No-MT groups (p = 0.29).

Conclusion:

The study reveals that metformin use in stroke patients with T2DM results in a less severe stroke and lower fatality and disability rates.

Safety, feasibility and efficacy of metformin and sitagliptin in patients with a TIA or minor ischaemic stroke and impaired glucose tolerance

INTRODUCTION

Impaired glucose tolerance (IGT) is highly prevalent after stroke and is associated with recurrent stroke and unfavourable outcome.

OBJECTIVES

We aimed to assess the feasibility, safety and effects on glucose metabolism of metformin or sitagliptin in patients with transient ischaemic attack (TIA) or minor ischaemic stroke and IGT.

DESIGN

We performed a multicentre, randomised, controlled, open-label phase II trial with blinded outcome assessment.

INTERVENTIONS

Patients were randomised in a 2:1:1 ratio to 'no medication', sitagliptin or metformin.

PRIMARY AND SECONDARY OUTCOME MEASURES

Primary outcome measures were baseline adjusted differences of 2-hour postload glucose; secondary outcome measures fasting glucose, glycosylated haemoglobin 1c (HbA1c) levels, tolerability and safety of metformin and sitagliptin at 6 months. Patients on metformin or sitagliptin were contacted by telephone for recording of possible adverse events and to support continuation of treatment at 2 weeks, 6 weeks and 3 months after inclusion. These events were not analysed as outcome measures.

RESULTS

Fifty-three patients were randomised to control group, 26 to metformin and 22 to sitagliptin. We found no significant differences in 2-hour postload glucose between patients on antidiabetic drugs and controls ((-0.04 mmol/L (95% CI -0.53 to 0.45)). Patients in the treatment arms had reduced fasting glucose: ((-0.21 mmol/L (95% CI -0.36 to -0.06)) and HbA1c levels ((-1.16 mmol/mol (95% CI -1.84 to -0.49)). Thirteen patients (50%) on metformin and 7 (32%) on sitagliptin experienced side effects. Sixteen patients (61%) in the metformin and 13 (59%) in the sitagliptin group were still on treatment after 6 months.

CONCLUSIONS

Metformin and sitagliptin were both effective in reducing fasting glucose and HbA1c levels in patients with recent TIA or minor ischaemic stroke and IGT. However, the reduction of glucose levels and sample size was relatively small. The clinical relevance, therefore, needs to be tempered. A phase III trial is needed to investigate whether medical treatment, compared with lifestyle intervention or a combination of both, not only improves glucose metabolism in IGT, but also leads to reduction of recurrent TIA or ischaemic stroke in these patients.

TRIAL REGISTRATION NUMBER

NL3048.

Feasibility trial of metformin XR in people with pre-diabetes and stroke (MIPPS)-randomised open blinded endpoint controlled trial

AIMS

Pre-diabetes is a common condition that affects about 16.4% of Australian adults. Hyperglycaemia is a strong risk factor for the development of stroke. Metformin XR is an approved medication to treat type 2 diabetes in Australia but not pre-diabetes. Additionally, whether it is tolerated following a stroke is unclear. In this pilot study, we aimed to assess the feasibility of Metformin XR in people with stroke and pre-diabetes.

METHODS

In this PROBE design trial, people who had recent stroke (within 3 months) with pre-diabetes were randomized to either the active arm (n = 13) receiving usual care plus Metformin XR (500 mg daily increased to a total daily dose of 1500 mg) or the control group receiving only usual care (n = 13). At baseline & after four months of intervention, clinical and biomedical characteristics, cardiovascular risk factors and medication data were recorded. At one month and 2.5 months into the study, compliance rateandside effects were determined.

RESULTS

This trial showed that it is feasible to recruit, retain and monitor participants. However, the compliance rate was low. Adherence to metformin XR was 52% (IQR:42% to 61%) based on the remaining tablets in the container after 4 months of intervention. None of the reported side effects were deemed to be related to the study treatment and no significant differences were observed between the metformin XR and the control group.

CONCLUSION

Treatment with Metformin XR in participants admitted with stroke and with pre-diabetes is feasible and safe. Strategies are needed to improve adherence in future trials.

The beneficial roles of metformin on the brain with cerebral ischaemia/reperfusion injury

Cerebral ischaemia/reperfusion (I/R) injury is the transient loss, followed by rapid return, of blood flow to the brain. This condition is often caused by strokes and heart attacks. The underlying mechanisms resulting in brain damage during cerebral I/R injury include mitochondrial dysregulation, increased oxidative stress/reactive oxygen species, blood-brain-barrier breakdown, inflammation of the brain, and increased neuronal apoptosis. Metformin is the first-line antidiabetic drug which has recently been shown to be capable of acting through the aforementioned pathways to improve recovery following cerebral I/R injury. However, some studies have suggested that metformin therapy may have no effect or even worsen recovery following cerebral I/R injury. The present review will compile and examine the available in vivo, in vitro, and clinical data concerning the neuroprotective effects of metformin following cerebral I/R injury. Any contradictory evidence will also be assessed and presented to determine the actual effectiveness of metformin treatment in stroke recovery.

Neuro-Protective Role of Metformin in Patients with Acute Stroke and Type 2 Diabetes Mellitus via AMPK/Mammalian Target of Rapamycin (mTOR) Signaling Pathway and Oxidative Stress

Background

We investigated the effects of metformin on neurological function and oxidative stress in patients with type 2 diabetes mellitus with acute stroke.

Material/Methods

We randomly assigned 80 acute stroke patients to 2 groups: the metformin combined group and the insulin group. Each group had 40 patients and all were treated with standard stroke treatment. The indexes of nervous functional score and oxidative stress were measured before and 2 weeks after treatment. The primary fetal rat hippocampal neurons were gradually matured after 7 days of culture, and divided into the control group (Con), the oxygen-glucose deprivation model group (Mod), and the metformin group (Met). In the Met group, 10 mmol/L metformin was added, and the Con group and the Mod group received equal volumes of cell culture fluid. Cell viability, cell apoptosis rate, and the expression of Bax, Bcl-2, AMPK, pAMPK and mTOR were detected; MDA content and SOD activity were also detected.

Results

Before treatment, there was no difference in the metrical indexes between the 2 groups. After treatment, the treatment group was better than the control group in neurological function scores and multiple oxidative stress-related indicators. The experimental results of primary fetal rat hippocampal neuronal cells suggest that this mechanism of improvement is closely related to the AMPK/mTOR signaling pathway.

Conclusions

Metformin can improve the neurological function and oxidative stress status of acute stroke patients with type 2 diabetes, and its mechanism may be related to the AMPK/mTOR signaling pathway and oxidative stress.

A story of metformin-butyrate synergism to control various pathological conditions as a consequence of gut microbiome modification: Genesis of a wonder drug?

The most widely prescribed oral anti-diabetic agent today in the world today is a member of the biguanide class of drugs called metformin. Apart from its use in diabetes, it is currently being investigated for its potential use in many diseases such as cancer, cardiovascular diseases, Alzheimer's disease, obesity, comorbidities of diabetes such as retinopathy, nephropathy to name a few. Numerous in-vitro and in-vivo studies as well as clinical trials have been and are being conducted with a vast amount of literature being published every day. Numerous mechanisms for this drug have been proposed, but they have been unable to explain all the actions observed clinically. It is of interest that insulin has a stimulatory effect on cellular growth. Metformin sensitizes the insulin action but believed to be beneficial in cancer. Like -wise metformin is shown to have beneficial effects in opposite sets of pathological scenario looking from insulin sensitization point of view. This requires a comprehensive review of the disease conditions which are claimed to be affected by metformin therapy. Such a comprehensive review is presently lacking. In this review, we begin by examining the history of metformin before it became the most popular anti-diabetic medication today followed by a review of its relevant molecular mechanisms and important clinical trials in all areas where metformin has been studied and investigated till today. We also review novel mechanistic insight in metformin action in relation to microbiome and elaborate implications of such aspect in various disease states. Finally, we highlight the quandaries and suggest potential solutions which will help the researchers and physicians to channel their research and put this drug to better use.

Metformin and sitAgliptin in patients with impAired glucose tolerance and a recent TIA or minor ischemic Stroke (MAAS): study protocol for a randomized controlled trial

Background

Impaired glucose tolerance is present in one third of patients with a TIA or ischemic stroke and is associated with a two-fold risk of recurrent stroke. Metformin improves glucose tolerance, but often leads to side effects.

The aim of this study is to explore the feasibility, safety, and effects on glucose metabolism of metformin and sitagliptin in patients with TIA or minor ischemic stroke and impaired glucose tolerance. We will also assess whether a slow increase in metformin dose and better support and information on this treatment will reduce the incidence of side effects in these patients.

Methods/Design

The Metformin and sitAgliptin in patients with impAired glucose tolerance and a recent TIA or minor ischemic Stroke trial (MAAS trial) is a phase II, multicenter, randomized, controlled, open-label trial with blinded outcome assessment. Non-diabetic patients (n = 100) with a recent (<6 months) TIA, amaurosis fugax or minor ischemic stroke (modified Rankin scale ≤ 3) and impaired glucose tolerance, defined as 2-hour post-load glucose levels between 7.8 and 11.0 mmol/L after repeated standard oral glucose tolerance test, will be included. Patients with renal or liver impairment, heart failure, chronic hypoxic lung disease stage III–IV, history of lactate acidosis or diabetic ketoacidosis, pregnancy or breastfeeding, pancreatitis and use of digoxin will be excluded. The patients will be randomly assigned in a 1:1:2 ratio to metformin, sitagliptin or “no treatment.” Patients allocated to metformin will start with 500 mg twice daily, which will be slowly increased during a 6-week period to a twice daily dose of 1000 mg. Patients allocated to sitagliptin will be treated with a daily fixed dose of 100 mg. The study has been registered as NTR 3196 in The Netherlands Trial Register. Primary outcomes include percentage still on treatment, percentage of (serious) adverse events, and the baseline adjusted difference in 2-hour post-load glucose levels at 6 months.

Discussion

This study will give more information about the feasibility and safety of metformin and sitagliptin as well as the effect on 2-hour post-load glucose levels at 6 months in patients with TIA or ischemic stroke and impaired glucose tolerance.

Trial registration number

NTR3196, Date of registration: 15 December 2011.

Prediabetes in patients with stroke or transient ischemic attack: prevalence, risk and clinical management

BACKGROUND

The prevalence of diabetes is emerging worldwide and is an important modifiable risk factor for stroke. People with prediabetes, an intermediate metabolic state between normal glucose metabolism and diabetes, have a tenfold increased risk of developing diabetes compared to those with a normal glucose metabolism. Prediabetes is comprised of impaired fasting glucose and/or impaired glucose tolerance and/or disturbed glycosylated hemoglobin levels. Prediabetes is highly prevalent in nondiabetic patients with transient ischemic attack (TIA) or ischemic stroke and nearly doubles their risk of stroke. This offers new options for secondary stroke prevention.

SUMMARY

Several detection methods exist for identifying (pre)diabetes, including fasting plasma glucose, 2-hour postload glucose and glycosylated hemoglobin levels. The concordance between these tests is not 100%, and they seem to be complementary. Screening for (pre)diabetes after stroke with fasting plasma glucose levels alone is insufficient, and 2-hour postload glucose and/or glycosylated hemoglobin levels should be determined as well. The prevalence of prediabetes in previously nondiabetic patients with a recent TIA or stroke ranges from 23 to 53%. This high prevalence in the acute phase after stroke can be transient or persistent, representing undiagnosed abnormal glucose metabolism. Impaired fasting glucose and impaired glucose tolerance have different pathophysiological mechanisms, including hepatic insulin resistance and muscle insulin resistance, respectively. Prediabetes seems to be a modest predictor for stroke, but doubles the risk for recurrent stroke. The relation between prediabetes after stroke and functional outcome is still unknown. However, it is most likely that prediabetes is a risk factor for a poor clinical outcome after stroke. There is a growing recognition that patients with prediabetes should be treated more aggressively. Both lifestyle and pharmacological interventions are possible treatment strategies. They are at least equally effective in preventing progression to diabetes. Lifestyle changes are difficult to maintain over a long period. The evidence of pharmacological interventions on stroke or other cardiovascular diseases is limited though and is still subject of several clinical trials.

CONCLUSIONS

As the prevalence of prediabetes is growing rapidly, prediabetes might become one of the most important modifiable therapeutic targets in both primary and secondary prevention.