Efficacy of lower doses of pioglitazone after stroke or transient ischaemic attack in patients with insulin resistance

AIMS

Pioglitazone is a potent insulin-sensitizing drug with anti-atherosclerotic properties, but adverse effects have limited its use. We assessed the benefits and risks of lower versus higher doses of pioglitazone taken by participants in the Insulin Resistance Intervention in Stroke Trial.

MATERIALS AND METHODS

Efficacy [myocardial infarction (MI) or recurrent stroke] new-onset diabetes) and adverse outcomes (oedema, weight gain, heart failure and bone fracture) were examined for subjects assigned to pioglitazone or placebo within strata defined by mode dose of study drug taken (i.e. the dose taken on most days in the study).

RESULTS

Among the 1938 patients randomized to pioglitazone, the mode dose was <15 mg/day in 546 participants, 15 mg/day in 128, 30 mg/day in 89, and 45 mg/day in 1175. There was no significant effect on stroke/MI or new-onset diabetes with <15 mg/day. For 15 mg/30 mg/day pooled, the adjusted hazard ratios (95% CI) for stroke/MI were 0.48 (0.30, 0.76; p = .002) and 0.74 (0.69, 0.94) for 45 mg/day. For new-onset diabetes, the adjusted hazard ratios were 0.34 (0.15, 0.81; p = .001) and 0.31 (0.59, 0.94; p = .001) respectively. For oedema, weight gain and heart failure, the risk estimates for pioglitazone were lower for subjects taking <45 mg daily. For fractures, the increased risk with pioglitazone was similar across all dose strata.

CONCLUSIONS

Lower doses of pioglitazone appear to confer much of the benefit with less adverse effects than the full dose. Further study is needed to confirm these findings so that clinicians may optimize dosing of this secondary prevention strategy in patients with stroke.

Association Between Hyperhomocysteinemia Combined with Metabolic Syndrome and Higher Prevalence of Stroke in Chinese Adults Who Have Elevated Blood Pressure

Background

Hyperhomocysteinemia (HHcy) and metabolic syndrome (MS) are established cardiovascular risk factors of stroke and are frequently associated with hypertension. However, studies on the association between HHcy combined with MS and stroke risk in hypertensive patients were absent.

Material/Methods

In 14 059 selected participants with elevated blood pressure, we assessed the prevalence of the MS and stroke. We defined HHcy as plasma total homocysteine >15 μmol/L. MS was defined according to the Chinese Diabetes Society (CDS) criterion. Multivariable analysis was used to examine the association of HHcy or (and) MS with stroke risk in different models.

Results

The prevalence rates of HHcy and MS were 49.96% and 42.21%, respectively. Patients with stroke had higher plasma total homocysteine levels and a higher prevalence of MS (P<0.001). Multivariable analyses indicated that HHcy and MS are independently associated with higher prevalence of stroke (adjusted-odds ratio (OR): 1.36, 95% CI 1.17 to 1.58, P<0.001; adjusted-OR: 1.68, 95% CI 1.44 to 1.96, P<0.001, respectively). Those with combined HHcy and MS had higher odds of stroke than those with isolated HHcy or MS (adjusted-OR: 1.78, 95% CI 1.47 to 2.15, P<0.001; adjusted-OR: 1.39, 95% CI 1.13 to 1.70, P=0.002, respectively).

Conclusions

HHcy combined with MS was associated with higher prevalence of stroke in Chinese adults with elevated blood pressure.

Pioglitazone use associated with reduced risk of the first attack of ischemic stroke in patients with newly onset type 2 diabetes: a nationwide nested case-control study

Background

Pioglitazone use is known to be associated with a reduced risk of recurrent stroke in patients with diabetes mellitus (DM) who have a history of stroke. However, it is unclear whether this benefit extends to patients without a history of stroke. We aimed to evaluate the association between pioglitazone use and development of first attack of ischemic stroke in patients with newly diagnosed type 2 DM.

Methods

Using longitudinal nationwide data from the 2002–2017 Korean National Health Insurance Service DM cohort, we analyzed the association between pioglitazone use and incidence of primary ischemic stroke using a nested case–control study. Among 128,171 patients with newly onset type 2 DM who were stroke-free at the time of DM diagnosis, 4796 cases of ischemic stroke were identified and matched to 23,980 controls based on age, sex, and the onset and duration of DM. The mean (standard deviation) follow-up time was 6.08 (3.34) years for the cases and controls. Odds ratios (ORs) and 95% confidence intervals (CIs) for the association between ischemic stroke and pioglitazone use were analyzed by multivariable conditional logistic regression analyses adjusted for comorbidities, cardiometabolic risk profile, and other oral antidiabetic medications.

Results

Pioglitazone use was associated with a reduced risk of first attack of ischemic stroke (adjusted OR [AOR] 0.69, 95% CI 0.60–0.80) when compared with non-use. Notably, pioglitazone use was found to have a dose-dependent association with reduced rate of ischemic stroke emergence (first cumulative defined daily dose [cDDD] quartile AOR 0.99, 95% CI 0.74–1.32; second quartile, AOR 0.77, 95% CI 0.56–1.06; third quartile, AOR 0.51, 95% Cl 0.36–0.71; highest quartile, AOR 0.48, 95% CI 0.33–0.69). More pronounced risk reduction was found in patients who used pioglitazone for more than 2 years. A further stratified analysis revealed that pioglitazone use had greater protective effects in patients with risk factors for stroke, such as high blood pressure, obesity, and current smoking.

Conclusions

Pioglitazone use may have a preventive effect on primary ischemic stroke in patients with type 2 DM, particularly in those at high risk of stroke.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-021-01339-x.

Telmisartan use and risk of dementia in type 2 diabetes patients with hypertension: A population-based cohort study

BACKGROUND

Angiotensin receptor blockers (ARBs) may have protective effects against dementia occurrence in patients with hypertension (HTN). However, whether telmisartan, an ARB with peroxisome proliferator-activated receptor γ (PPAR-γ)-modulating effects, has additional benefits compared to other ARBs remains unclear.

METHODS AND FINDINGS

Between 1997 and 2013, 2,166,944 type 2 diabetes mellitus (T2DM) patients were identified from the National Health Insurance Research Database of Taiwan. Patients with HTN using ARBs were included in the study. Patients with a history of stroke, traumatic brain injury, or dementia were excluded. Finally, 65,511 eligible patients were divided into 2 groups: the telmisartan group and the non-telmisartan ARB group. Propensity score matching (1:4) was used to balance the distribution of baseline characteristics and medications. The primary outcome was the diagnosis of dementia. The secondary outcomes included the diagnosis of Alzheimer disease and occurrence of symptomatic ischemic stroke (IS), any IS, and all-cause mortality. The risks between groups were compared using a Cox proportional hazard model. Statistical significance was set at p < 0.05. There were 2,280 and 9,120 patients in the telmisartan and non-telmisartan ARB groups, respectively. Patients in the telmisartan group had a lower risk of dementia diagnosis (telmisartan versus non-telmisartan ARBs: 2.19% versus 3.20%; HR, 0.72; 95% CI, 0.53 to 0.97; p = 0.030). They also had lower risk of dementia diagnosis with IS as a competing risk (subdistribution HR, 0.70; 95% CI, 0.51 to 0.95; p = 0.022) and with all-cause mortality as a competing risk (subdistribution HR, 0.71; 95% CI, 0.53 to 0.97; p = 0.029). In addition, the telmisartan users had a lower risk of any IS (6.84% versus 8.57%; HR, 0.79; 95% CI, 0.67 to 0.94; p = 0.008) during long-term follow-up. Study limitations included potential residual confounding by indication, interpretation of causal effects in an observational study, and bias caused by using diagnostic and medication codes to represent real clinical data.

CONCLUSIONS

The current study suggests that telmisartan use in hypertensive T2DM patients may be associated with a lower risk of dementia and any IS events in an East-Asian population.

Stroke Prevention: Little-Known and Neglected Aspects

Combining available therapies has the potential to reduce the risk of stroke by 80% or more. A comprehensive review of all aspects of stroke prevention would be very lengthy; in this narrative review, we focus on some aspects of stroke prevention that are little-known and/or neglected. These include the following: (1) implementation of a Mediterranean diet; (2) B vitamins to lower homocysteine; (3) coordinated approaches to smoking cessation; (4) intensive lipid-lowering therapy; (5) lipid lowering in the elderly; (6) physiologically individualized therapy for hypertension based on renin/aldosterone phenotyping; (7) avoiding excessive blood pressure reduction in patients with stiff arteries; (8) treatment of insulin resistance with pioglitazone in stroke patients with prediabetes and diabetes; (9) impaired activation of clopidogrel in patients with variants of CYP2C19; (10) aspirin pseudoresistance due to enteric coating; (11) rationale for anticoagulation in patients with embolic stroke of unknown source; (12) pharmacologic properties of direct-acting oral anticoagulants that should be considered when choosing among them; (13) the identification of which patients with asymptomatic carotid stenosis are at a high enough risk to benefit from carotid endarterectomy or stenting; and (14) the importance of age in choosing between endarterectomy and stenting. Stroke prevention could be improved by better recognition of these issues and by implementation of the principles derived from them.

Triglyceride/High-Density Lipoprotein Cholesterol Ratio: A Clue to Metabolic Syndrome, Insulin Resistance, and Severe Atherosclerosis

High serum levels of triglycerides (Tg) and low levels of high-density lipoprotein cholesterol (HDL-C) are characteristic of the Metabolic Syndrome (MetS). We assessed the ratio of Tg to HDL-C as a way to identify MetS and insulin resistance. We also evaluated its association with severity of carotid atherosclerosis. Data were analyzed from three cohorts totaling 13,908 participants. MetS was defined according to the International Diabetes Federation criteria. Optimal cut-off for Tg/HDL-C ratio was obtained using Youden's index in receiver-operating characteristic (ROC) curve analyses. The risk of MetS and IR in those with a Tg/HDL-C ratio above the optimum cutoff was evaluated by logistic regression analysis. A Tg/HDL-C ratio above the optimal cutoff level significantly increased the odds ratio for MetS in the three cohorts (OR 6.00, 4.04, and 3.50, least in the healthy population), identified insulin resistance defined by the homeostatic model of insulin resistance (HOMA-IR) (p < 0.0001), and was strongly associated with atherosclerosis severity (p = 0.0001). Tg/HDL-C ratio identifies persons with MetS, insulin resistance, and severe atherosclerosis. It should be used more widely to identify patients at high risk. This is clinically important because insulin resistance is treatable.

Diabetes, stroke, and neuroresilience: looking beyond hyperglycemia

Ischemic stroke is a leading cause of morbidity and mortality among type 2 diabetic patients. Preclinical and translational studies have identified critical pathophysiological mediators of stroke risk, recurrence, and poor outcome in diabetic patients, including endothelial dysfunction and inflammation. Most clinical trials of diabetes and stroke have focused on treating hyperglycemia alone. Pioglitazone has shown promise in secondary stroke prevention for insulin-resistant patients; however, its use is not yet widespread. Additional research into clinical therapies directed at diabetic pathophysiological processes to prevent stroke and improve outcome for diabetic stroke survivors is necessary. Resilience is the process of active adaptation to a stressor. In patients with diabetes, stroke recovery is impaired by insulin resistance, endothelial dysfunction, and inflammation, which impair key neuroresilience pathways maintaining cerebrovascular integrity, resolving poststroke inflammation, stimulating neural plasticity, and preventing neurodegeneration. Our review summarizes the underpinnings of stroke risk in diabetes, the clinical consequences of stroke in diabetic patients, and proposes hypotheses and new avenues of research for therapeutics to stimulate neuroresilience pathways and improve stroke outcome in diabetic patients.

Recent advances in preventing recurrent stroke

Since a 2017 update, there have been important advances in stroke prevention. These include new evidence about nutrition, antiplatelet therapy, anticoagulation, lipid-lowering therapy, hypertension control, pioglitazone, and carotid endarterectomy and stenting. Evidence regarding toxic metabolites produced by the intestinal microbiome from egg yolk and red meat has important dietary implications, particularly for patients with impaired renal function, including the elderly. They should avoid egg yolk and red meat and limit the intake of animal flesh. Higher doses of folic acid may be needed for patients with the T allele of MTHFR, so it may not be sufficient to give vitamin B12 (methylcobalamin) alone, even in countries with folate fortification. There is now good evidence that lipid-lowering therapy is even more beneficial in the elderly than in younger patients; we should be using lipid-lowering therapy more intensively, often/usually combining statins with ezetimibe. There is new evidence that lower systolic blood pressure targets are better for most patients, but a subgroup with stiff arteries, a wide pulse pressure, and a diastolic pressure of <60 would be more likely to be harmed than helped by aiming for a systolic target of <120 mmHg. There is a better understanding of how the pharmacological properties of direct-acting oral anticoagulants and the metabolism of antiplatelet agents should inform decisions about the use of these agents. Pioglitazone markedly reduces the risk of stroke, both in diabetics and prediabetics; it should be used more widely. It is now clear that carotid endarterectomy is safer than stenting and that the difference is strongly affected by age. Most patients, and in particular older patients, would be better served by endarterectomy than stenting.

Pioglitazone for primary stroke prevention in Asian patients with type 2 diabetes and cardiovascular risk factors: a retrospective study

Background

Studies assessing the efficacy of pioglitazone solely for primary stroke prevention in Asian patients with type 2 diabetes mellitus (DM) and present multiple cardiovascular (CV) risk factors are rare. Thus, we aimed to assess the effect of pioglitazone on primary stroke prevention in Asian patients with type 2 DM without established CV diseases but with risk factors for CV diseases.

Methods

Between 2000 and 2012, we enrolled patients aged ≥ 18 years, who were newly diagnosed with type 2 diabetes and had at least one of the following CV risk factors: hypertension and hyperlipidemia. Patients with a history of stroke and those using insulin or glucagon-like peptide-1 agonist for more than 3 months were excluded. Patients were divided into the pioglitazone and non-pioglitazone groups based on their receipt of pioglitazone during the follow-up period. Propensity-score matching (1:1) was used to balance the distribution of the baseline characteristics and medications. Follow-up was terminated upon ischemic stroke development, withdrawal from the insurance system, or on December 31, 2013, whichever occurred first. The overall incidence of new-onset ischemic stroke in the two groups was subsequently compared. The subgroup analyses of ischemic stroke were conducted using different baseline features. Additionally, the effect of pioglitazone exposure dose on the occurrence of ischemic stroke was evaluated. Chi square test, Student’s t-test, competing risk regression models, Kaplan–Meier method, and log-rank test were some of the statistical tests conducted.

Results

A total of 13 078 patients were included in the pioglitazone and non-pioglitazone groups. Compared with patients who did not receive pioglitazone, those administered pioglitazone had a lower risk of developing ischemic stroke (adjusted hazard ratio: 0.78; 95% confidence interval: 0.62–0.95). The subgroup analyses defined by different baseline features did not reveal significant alterations in the observed effect of pioglitazone. Moreover, a significant decreasing trend in ischemic stroke risk with an increase in pioglitazone dose (p-value for trend = 0.04) was observed.

Conclusion

Pioglitazone use decreased the risk of new-onset ischemic stroke in Asian patients with type 2 DM and CV risk factors.

Trial registration number CMUH104-REC2-115-CR4

Choosing the right therapy for a patient with asymptomatic carotid stenosis

Introduction: Most patients with asymptomatic carotid stenosis (ACS) now have a lower risk with intensive medical therapy than with stenting (CAS) or endarterectomy (CEA); the annual risk of stroke or death with intensive medical therapy is ~ 0.5%, vs. a periprocedural risk with CAS of ~ 2.5-4.1% with CAS, and ~ 1.4-1.8% with CEA. The excess risk of CAS is greater in older patients.Areas covered: Discussed are the need for intensive medical therapy, the nature of intensive medical therapy, approaches to identifying the few patients with ACS who could benefit from CEA or CAS, and which patients would be better suited to CEA vs. CAS.Expert opinion: All patients with ACS are at high risk of cardiovascular events, soshould receive intensive medical therapy including lifestyle modification, intensive lipid-lowering, B vitamins to lower homocysteine (using methylcobalamin rather than cyanocobalamin), and appropriate antithrombotic therapy. High-risk patients who could benefit from intervention can be identified by clinical and imaging features including transcranial Doppler embolus detection, ulceration, intraplaque hemorrhage, reduced cerebrovascular reserve, plaque echolucency, silent infarction on brain imaging, and progression of stenosis. Most patients whose risk of stroke warrants intervention would be better treated with CEA than with CAS.

Pioglitazone and PPAR-γ modulating treatment in hypertensive and type 2 diabetic patients after ischemic stroke: a national cohort study

Background and aim

Peroxisome proliferator-activated receptor-γ (PPAR-γ) modulating treatment may have cardiovascular benefits in type 2 diabetes mellitus (T2DM) patients after ischemic stroke (IS). However, whether there are additional benefits from intensive PPAR-γ modulating treatments in Asian patients with T2DM and hypertension (HTN) after IS remains unknown.

Methods

Between 2001 and 2013, patients admitted due to IS were identified from the National Health Insurance Research Database of Taiwan. Patients with T2DM and HTN using angiotensin receptor blockers were further included. Eligible patients were divided into two groups: (1) pioglitazone and (2) non-pioglitazone oral anti-diabetic agent groups. Propensity score matching (1:2) was used to balance the distribution of baseline characteristics, stroke severity and medications. The primary outcome was recurrent IS. Subgroup analysis for recurrent IS in pioglitazone and/or telmisartan users, the trend of IS risks across different PPAR-γ intensity treatments, and dose-dependent outcomes across different pioglitazone possession ratios were further studied. Statistical significance was set at p < 0.05 and p < 0.1 for clinical outcomes and interaction of subgroup analyses, respectively.

Results

There were 3190 and 32,645 patients in the pioglitazone and non-pioglitazone groups. Patients of the pioglitazone group had a lower risk of recurrent IS (subdistribution hazard ratio, 0.91; 95% confidence interval 0.84–0.99). Pioglitazone was also associated with reduced recurrent IS in patients who also used telmisartan (p for interaction = 0.071). A graded correlation was found a borderline significant trend between the intensity of PPAR-γ therapy and following IS (p = 0.076). The dose-dependent outcome also showed that a borderline significant trend that higher pioglitazone possession ratio was associated with a lower risk of recurrent IS (p = 0.068).

Conclusions

The current study suggests that the use of pioglitazone in type 2 diabetic and hypertensive IS patients is associated with fewer recurrent IS events in an Asian population. Concurrent telmisartan use or a higher pioglitazone possession ratio may have a trend of increased pleiotropic effects, which could possibly be related to higher PPAR-γ effects. Future studies are warranted to confirm or refute the clinical effects and the possible mechanism of more intensive PPAR-γ-modulating treatments.