Impact of peripheral arterial disease in patients with diabetes—Results from PROactive (PROactive 11)

Cardiovascular Effectiveness and Safety of Antidiabetic Drugs in Patients with Type 2 Diabetes and Peripheral Artery Disease: Systematic Review

Peripheral artery disease (PAD) is an atherosclerotic condition commonly complicating type 2 diabetes (T2D), leading to poor quality of life and increased risk of major adverse lower-limb (MALE) and cardiovascular (CV) events (MACE). Therapeutic management of PAD in T2D patients is much more arduous, often due to bilateral, multi-vessel, and distal vascular involvement, in addition to increased systemic polyvascular atherosclerotic burden. On the other hand, the pathophysiological link between PAD and T2D is very complex, involving mechanisms such as endothelial dysfunction and increased subclinical inflammation in addition to chronic hyperglycemia. Therefore, the clinical approach should not ignore vascular protection with the aim of reducing limb and overall CV events besides a mere glucose-lowering effect. However, the choice of the best medications in this setting is challenging due to low-grade evidence or lacking targeted studies in PAD patients. The present review highlighted the strong relationship between T2D and PAD, focusing on the best treatment strategy to reduce CV risk and prevent PAD occurrence and worsening in patients with T2D. The Medline databases were searched for studies including T2D and PAD up to June 2024 and reporting the CV effectiveness and safety of the most used glucose-lowering agents, with no restriction on PAD definition, study design, or country. The main outcomes considered were MACE-including nonfatal acute myocardial infarction, nonfatal stroke, and CV death-and MALE-defined as lower-limb complications, amputations, or need for revascularization. To the best of our current knowledge, GLP-1 receptor agonists and SGLT2 inhibitors represent the best choice to reduce CV risk in T2D and PAD settings, but a personalized approach should be considered. GLP-1 receptor agonists should be preferred in subjects with prevalent atherosclerotic burden and a history of previous MALE, while SGLT2 inhibitors should be used in those with heart failure if overall CV benefits outweigh the risk of lower-limb complications.

Peroxisome proliferator-activated receptor gamma agonists for preventing recurrent stroke and other vascular events in people with stroke or transient ischaemic attack

BACKGROUND

Peroxisome proliferator-activated receptor gamma (PPAR-γ) agonists are insulin-sensitising drugs used for the treatment of insulin resistance. In addition to lowering glucose in diabetes, these drugs may also protect against hyperlipidaemia and arteriosclerosis, which are risk factors for stroke. This is an update of a review first published in January 2014 and subsequently updated in December 2017 and October 2019.

OBJECTIVES

To assess the efficacy and safety of PPAR-γ agonists in the secondary prevention of stroke and related vascular events for people with stroke or transient ischaemic attack (TIA).

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register (1 January 2022), the Cochrane Central Register of Controlled Trials (CENTRAL; 2021, Issue 12), MEDLINE (1949 to 1 January 2022), Embase (1980 to 1 January 2022), CINAHL (1982 to 1 January 2022), AMED (1985 to 1 January 2022), and 11 Chinese databases (1 January 2022). In an effort to identify further published, unpublished, and ongoing trials, we searched ongoing trials registers, reference lists, and relevant conference proceedings, and contacted authors and pharmaceutical companies. We did not impose any language restrictions.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) evaluating PPAR-γ agonists versus placebo for the secondary prevention of stroke and related vascular events in people with stroke or TIA, with the outcomes of recurrent stroke, vascular events, and adverse events.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the titles and abstracts of identified records, selected studies for inclusion, extracted eligible data, cross-checked the data for accuracy, and assessed methodological quality and risk of bias. We evaluated the certainty of evidence for each outcome using the GRADE approach.

MAIN RESULTS

We identified five RCTs with 5039 participants; two studies had a low risk of bias for all domains. Four studies evaluated the drug pioglitazone, and one study evaluated rosiglitazone. The participants in different studies were heterogeneous. Recurrent stroke Three studies evaluated the number of participants with recurrent stroke (4979 participants, a single study contributing 3876 of these). Peroxisome proliferator-activated receptor gamma agonists probably reduce the recurrence of stroke compared with placebo (risk ratio (RR) 0.66, 95% confidence interval (CI) 0.44 to 0.99; moderate-certainty evidence). Adverse events Evidence that adverse events occurred more frequently in participants treated with PPAR-γ agonists when compared with placebo was uncertain due to wide confidence intervals and high levels of statistical heterogeneity: risk difference 10%, 95% CI -8% to 28%; low-certainty evidence). Data were available on additional composite outcomes reflecting serious vascular events (all-cause death and other major vascular events; all-cause mortality, non-fatal myocardial infarction or non-fatal stroke) from one study in 984 people. This study provided low-certainty evidence that PPAR-γ agonists led to fewer events (data not meta-analysed). Vascular events Peroxisome proliferator-activated receptor gamma agonists given over a mean duration of 34.5 months in a single trial of 984 participants may reduce serious vascular events expressed as a composite outcome of total events of cardiovascular death, non-fatal myocardial infarction or non-fatal stroke (RR 0.73, 95% CI 0.54 to 0.99; low-certainty evidence). Other outcomes One study in 20 people measured insulin sensitivity, and one study in 40 people measured the ubiquitin-proteasome activity in carotid plaques. Our confidence in the improvements observed with PPAR-γ agonists were limited by small sample sizes and risk of bias. None of the studies reported the number of participants with disability due to vascular events or improvement in quality of life.

AUTHORS' CONCLUSIONS

Peroxisome proliferator-activated receptor gamma agonists probably reduce recurrent stroke and total events of cardiovascular death, non-fatal myocardial infarction or non-fatal stroke, and may improve insulin sensitivity and the stabilisation of carotid plaques. Their effects on adverse events are uncertain. Our conclusions should be interpreted with caution considering the small number and the quality of the included studies. Further well-designed, double-blind RCTs with large samples are required to assess the efficacy and safety of PPAR-γ agonists in the secondary prevention of stroke and related vascular events in people with stroke or TIA.

Praliciguat Promotes Ischemic Leg Reperfusion in Leptin Receptor-Deficient Mice

BACKGROUND

Lower-limb peripheral artery disease is one of the major complications of diabetes. Peripheral artery disease is associated with poor limb and cardiovascular prognoses, along with a dramatic decrease in life expectancy. Despite major medical advances in the treatment of diabetes, a substantial therapeutic gap remains in the peripheral artery disease population. Praliciguat is an orally available sGC (soluble guanylate cyclase) stimulator that has been reported both preclinically and in early stage clinical trials to have favorable effects in metabolic and hemodynamic outcomes, suggesting that it may have a potential beneficial effect in peripheral artery disease.

METHODS

We evaluated the effect of praliciguat on hind limb ischemia recovery in a mouse model of type 2 diabetes. Hind limb ischemia was induced in leptin receptor-deficient (Lepr^db/db) mice by ligation and excision of the left femoral artery. Praliciguat (10 mg/kg/day) was administered in the diet starting 3 days before surgery.

RESULTS

Twenty-eight days after surgery, ischemic foot perfusion and function parameters were better in praliciguat-treated mice than in vehicle controls. Improved ischemic foot perfusion was not associated with either improved traditional cardiovascular risk factors (ie, weight, glycemia) or increased angiogenesis. However, treatment with praliciguat significantly increased arteriole diameter, decreased ICAM1 (intercellular adhesion molecule 1) expression, and prevented the accumulation of oxidative proangiogenic and proinflammatory muscle fibers. While investigating the mechanism underlying the beneficial effects of praliciguat therapy, we found that praliciguat significantly downregulated Myh2 and Cxcl12 mRNA expression in cultured myoblasts and that conditioned medium form praliciguat-treated myoblast decreased ICAM1 mRNA expression in endothelial cells. These results suggest that praliciguat therapy may decrease ICAM1 expression in endothelial cells by downregulating Cxcl12 in myocytes.

CONCLUSIONS

Our results demonstrated that praliciguat promotes blood flow recovery in the ischemic muscle of mice with type 2 diabetes, at least in part by increasing arteriole diameter and by downregulating ICAM1 expression.

[Individualising antihypertensive therapy in patients with diabetes. A guideline by the Austrian Diabetes Association (update 2023)]

Hypertension is one of the most important comorbidities of diabetes, contributing significantly to death and leading to macrovascular and microvascular complications. When assessing the medical priorities for patients with diabetes, treating hypertension should be a primary consideration. In the present review practical approaches to hypertension in diabetes, including individualized targets for preventing specific complications are discussed according to current evidence and guidelines. Blood pressure values of about 130/80 mm Hg are associated with the best outcome; most importantly, at least blood pressure values < 140/90 mm Hg should be achieved in most patients. Angiotensin converting enzyme inhibitors or angiotensin receptor blockers should be preferred in patients with diabetes, especially in those who also have albuminuria or coronary artery disease. Most patients with diabetes require combination therapy to achieve blood pressure goals; agents with proven cardiovascular benefit should be used (including, besides angiotensin converting enzyme inhibitors and alternatively angiotensin receptor blockers, dihydropyridin-calcium antagonists and thiazide diuretics), preferable in single-pill combinations. Once the target is achieved, antihypertensive drugs should be continued. Newer antidiabetic medications such as SGLT-2-inhibitors or GLP1-receptor agonists have also antihypertensive effects.

The role of pioglitazone in the fight against insulin resistance, atherosclerosis, cardiovascular disease, and non-alcoholic fatty liver disease

Modern strategies for the treatment of type 2 diabetes mellitus involve the use of pathogenetically based approaches aimed at achieving optimal glycemic control and its long-term retention. Timely and rational use of 9 classes of hypoglycemic drugs, including as part of combination therapy, makes it possible to achieve significant success in diabetes therapy. One of the fundamental principles in the treatment of type 2 diabetes mellitus is the effect on insulin resistance. For this purpose, two groups of drugs are used: biguanides and thiazolidinediones (glitazones). The action of glitazones is directly related to an increase in the sensitivity of insulin-dependent tissues to insulin and a pronounced decrease in hyperinsulinemia in patients with type 2 diabetes. Of particular interest are the pathways of insulin signal transduction, the mechanisms of insulin resistance, and the possibilities of pathogenetic therapy with thiazolidinediones. Pioglitazone is currently the only available member of the thiazolidinedione class in the world, allowing to expand the management of diabetes mellitus by reducing insulin resistance in muscle and adipose tissue and glucose production by the liver. Its use can have a number of pleiotropic effects, including on cardiovascular diseases and non-alcoholic fatty liver disease, which expands the priorities for choosing hypoglycemic therapy in patients with type 2 diabetes at various stages of therapy.

Pioglitazone, Bladder Cancer and the Presumption of Innocence

BACKGROUND

Thiazolidinediones are potent exogenous agonists of PPAR-γ, which augment the effects of insulin to its cellular targets and mainly at the level of adipose tissue. Pioglitazone, the main thiazolidinedione in clinical practice, has shown cardiovascular and renal benefits in patients with type 2 diabetes, durable reduction of glycated hemoglobulin levels, important improvements of several components of the metabolic syndrome and beneficial effects of non-alcoholic fatty liver disease.

OBJECTIVE

Despite all of its established advantages, the controversy for an increased risk of developing bladder cancer, combined with the advent of newer drug classes that achieved major cardiorenal effects have significantly limited its use spreading a persistent shadow of doubt for its future role.

METHODS

Pubmed, Google and Scope databases have been thoroughly searched and relevant studies were selected.

RESULTS

This paper explores thoroughly both in vitro and in vivo (animal models and humans) studies that investigated the possible association of pioglitazone with bladder cancer.

CONCLUSION

Currently the association of pioglitazone with bladder cancer cannot be based on solid evidence. This evidence cannot justify its low clinical administration, especially in the present era of individualised treatment strategies. Definite clarification of this issue is imperative and urgently anticipated from future high quality and rigorous pharmacoepidemiologic research, keeping in mind its unique mechanism of action and its significant pleiotropic effects.

Stroke prevention in patients with type 2 diabetes or prediabetes. Recommendations from the Cerebrovascular Diseases Study Group, Spanish Society of Neurology

OBJECTIVE

To update the Spanish Society of Neurology's guidelines for stroke prevention in patients with type 2 diabetes or prediabetes, analysing the available evidence on the effect of metabolic control and the potential benefit of antidiabetic drugs with known vascular benefits in addition to conventional antidiabetic treatments in stroke prevention.

DEVELOPMENT

PICO-type questions (Patient, Intervention, Comparison, Outcome) were developed to identify practical issues in the management of stroke patients and to establish specific recommendations for each of them. Subsequently, we conducted systematic reviews of the PubMed database and selected those randomised clinical trials evaluating stroke as an independent variable (primary or secondary). Finally, for each of the PICO questions we developed a meta-analysis to support the final recommendations.

CONCLUSIONS

While there is no evidence that metabolic control reduces the risk of stroke, some families of antidiabetic drugs with vascular benefits have been shown to reduce these effects when added to conventional treatments, both in the field of primary prevention in patients presenting type 2 diabetes and high vascular risk or established atherosclerosis (GLP-1 agonists) and in secondary stroke prevention in patients with type 2 diabetes or prediabetes (pioglitazone).

Poor Renal and Cardiovascular Outcomes in Patients with Biopsy-Proven Diabetic Nephropathy

BACKGROUND

Despite the high mortality of cardiovascular disease (CVD) in diabetic patients with renal injury, few studies have compared cardiovascular characteristics and outcomes between patients with diabetic nephropathy (DN) and non-diabetic renal disease (NDRD).

METHODS

A total of 326 type 2 diabetes mellitus patients with renal biopsy were assigned to DN and NDRD groups. Echocardiography and Doppler ultrasound were performed to evaluate left ventricular hypertrophy (LVH) and peripheral atherosclerosis disease (PAD). Renal and cardiovascular survival rates were compared between the DN and NDRD groups by Kaplan-Meier analysis. Risk factors for renal and cardiovascular events in DN patients were identified by a Cox proportional hazards model.

RESULTS

In total, 179 patients entered the DN group (54.9%) and 147 made up the NDRD group (45.1%). The presence of diabetic retinopathy, family history of diabetes, and dependence on insulin therapy were associated with the presence of DN. DN patients had more CVD with more severe LVH and PAD. Poorer renal (log-rank χ2 = 26.534, p < 0.001) and cardiovascular (log-rank χ2 = 16.257, p < 0.001) prognoses were seen in the DN group. DR (HR 1.539, 95% CI 1.332-1.842), eGFR (HR 0.943, 95% CI 0.919-0.961), and 24-h proteinuria (HR 1.211, 95% CI 1.132-1.387) were identified as risk factors for renal endpoints. Age (HR 1.672, 95% CI 1.487-1.821), HbA1C (HR 1.398, 95% CI 1.197-1.876), and 24-h proteinuria (HR 1.453, 95% CI 1.289-1.672) were associated with cardiovascular endpoints.

CONCLUSION

Patients with DN had more severe CVD along with poorer renal and cardiovascular prognoses than those with NDRD.

Peripheral arterial disease and its correlates in patients with type 2 diabetes mellitus in a teaching hospital in northern Nigeria: a cross-sectional study

BACKGROUND

Peripheral arterial disease (PAD) is a risk factor for diabetic foot ulcer, limb amputation as well as coronary heart disease. It is more common in patients with diabetes mellitus (DM) and co-exists with peripheral neuropathy. Prevalence of PAD in type 2 DM patients in northern Nigeria is largely unknown. We investigated the occurrence and factors associated with PAD among patients with type 2 DM in a tertiary hospital in northern Nigeria.

METHODS

This was a cross- sectional analytic study. We recruited 200 patients with type 2 DM consecutively from the diabetes clinic of the Jos University Teaching Hospital. Ankle brachial index was assessed for each participant. Clinical information, anthropometric indices and blood samples were collected for assay. Data was analysed using CDC Epi-Info and logistic regression analysis was used to determine independent correlates of PAD.

RESULTS

PAD was present in 38.5%(n = 77) of subjects and it was associated with the female sex, age ≥ 50 years, Body mass index (BMI) ≥ 25 kg/m2 and low HDL cholesterol levels. However, on multiple logistic regression, a BMI ≥ 25 kg/m2 and a low HDL cholesterol level were independent correlates of PAD(adjusted OR = 2.13,95% CI = 1.04-4.36 and adjusted OR = 2.31, 95% CI = 1.04-5.15, respectively).

CONCLUSION

PAD is present in more than a third of patients with type 2 DM in a tertiary hospital in northern Nigeria. A BMI of ≥25 kg/m2 and low HDL cholesterol levels were independent correlates of PAD.

Insulin Resistance and Atherosclerosis: Implications for Insulin-Sensitizing Agents

Patients with type 2 diabetes mellitus (T2DM) are at high risk for macrovascular complications, which represent the major cause of mortality. Despite effective treatment of established cardiovascular (CV) risk factors (dyslipidemia, hypertension, procoagulant state), there remains a significant amount of unexplained CV risk. Insulin resistance is associated with a cluster of cardiometabolic risk factors known collectively as the insulin resistance (metabolic) syndrome (IRS). Considerable evidence, reviewed herein, suggests that insulin resistance and the IRS contribute to this unexplained CV risk in patients with T2DM. Accordingly, CV outcome trials with pioglitazone have demonstrated that this insulin-sensitizing thiazolidinedione reduces CV events in high-risk patients with T2DM. In this review the roles of insulin resistance and the IRS in the development of atherosclerotic CV disease and the impact of the insulin-sensitizing agents and of other antihyperglycemic medications on CV outcomes are discussed.

Peroxisome proliferator-activated receptor gamma agonists for preventing recurrent stroke and other vascular events in people with stroke or transient ischaemic attack

BACKGROUND

Peroxisome proliferator-activated receptor gamma (PPAR-γ) agonists are insulin-sensitising drugs used for the treatment of insulin resistance. In addition to lowering glucose in diabetes, these drugs may also protect against hyperlipidaemia and arteriosclerosis, which are risk factors for stroke. This is an update of a review first published in January 2014 and subsequently updated in December 2017.

OBJECTIVES

To assess the efficacy and safety of PPAR-γ agonists in the secondary prevention of stroke and related vascular events for people with stroke or transient ischaemic attack (TIA).

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register (30 July 2019), the Cochrane Central Register of Controlled Trials (CENTRAL; 2019, Issue 7), MEDLINE (1949 to 30 July 2019), Embase (1980 to 30 July 2019), CINAHL (1982 to 30 July 2019), AMED (1985 to 30 July 2019), and 11 Chinese databases (30 July 2019). In an effort to identify further published, unpublished, and ongoing trials, we searched ongoing trials registers, reference lists, and relevant conference proceedings, and contacted authors and pharmaceutical companies. We did not impose any language restrictions.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) evaluating PPAR-γ agonists versus placebo for the secondary prevention of stroke and related vascular events in people with stroke or TIA, with the outcomes of recurrent stroke, vascular events, and adverse events.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the titles and abstracts of identified records, selected studies for inclusion, extracted eligible data, cross-checked the data for accuracy, and assessed methodological quality and risk of bias. We evaluated the quality of evidence for each outcome using the GRADE approach.

MAIN RESULTS

We identified five RCTs with 5039 participants; two studies had a low risk of bias for all domains. Four studies evaluated the drug pioglitazone, and one study evaluated rosiglitazone. The participants in different studies were heterogeneous.Recurrent strokeThree studies evaluated the number of participants with recurrent stroke (4979 participants, a single study contributing 3876 of these). Peroxisome proliferator-activated receptor gamma agonists probably reduce the recurrence of stroke compared with placebo (risk ratio (RR) 0.66, 95% confidence interval (CI) 0.44 to 0.99; moderate-quality evidence).Adverse eventsEvidence that adverse events occurred more frequently in participants treated with PPAR-γ agonists when compared with placebo was uncertain due to wide confidence interval and high levels of statistical heterogeneity: risk difference 10%, 95% CI -8% to 28%; low-quality evidence).Data were available on additional composite outcomes reflecting serious vascular events (all-cause death and other major vascular events; all-cause mortality, non-fatal myocardial infarction or non-fatal stroke) from one study in 984 people. This study provided low-quality evidence that PPAR-γ agonists led to fewer events (data not meta-analysed).Vascular eventsPeroxisome proliferator-activated receptor gamma agonists given over a mean duration of 34.5 months in a single trial of 984 participants may reduce serious vascular events expressed as a composite outcome of total events of cardiovascular death, non-fatal myocardial infarction or non-fatal stroke (RR 0.73, 95% CI 0.54 to 0.99; low-quality evidence).Other outcomesOne study in 20 people measured insulin sensitivity, and one study in 40 people measured the ubiquitin-proteasome activity in carotid plaques. Our confidence in the improvements observed with PPAR-γ agonists were limited by small sample sizes and risk of bias. None of the studies reported the number of participants with disability due to vascular events or improvement in quality of life.

AUTHORS' CONCLUSIONS

Peroxisome proliferator-activated receptor gamma agonists probably reduce recurrent stroke and total events of cardiovascular death, non-fatal myocardial infarction or non-fatal stroke, and may improve insulin sensitivity and the stabilisation of carotid plaques. Their effects on adverse events are uncertain. Our conclusions should be interpreted with caution considering the small number and the quality of the included studies. Further well-designed, double-blind RCTs with large samples are required to assess the efficacy and safety of PPAR-γ agonists in the secondary prevention of stroke and related vascular events in people with stroke or TIA.

[Individualising antihypertensive therapy in patients with diabetes. A guideline by the Austrian Diabetes Association (Update 2019)]

Hypertension is one of the most important comorbidities of diabetes, contributing significantly to death and leads to macrovascular and microvascular complications. When assessing the medical priorities for patients with diabetes, treating hypertension should be a primary consideration. In the present review practical approaches to hypertension in diabetes, including individualized targets for preventing specific complications are discussed according to current studies and guidelines. According to recent studies, blood pressure values of about 130/80 mm Hg are associated with the best outcome. Angiotensin converting enzyme inhibitors and angiotensin receptor blockers are the most effective drugs for treating hypertension in diabetes. Calcium antagonists or diuretics are acceptable as second-line agents. Once the target is achieved, antihypertensive drugs should be continued. Newer antidiabetic medications such as SGLT-2-inhibitors or GLP1-receptor agonists have also antihypertensive effects.

Effects of basal insulin glargine and omega-3 on lower limb arterial disease outcome in patients with dysglycaemia: An analysis of the Outcome Reduction with an Initial Glargine INtervention (ORIGIN) trial

The impact of insulin or omega-3 supplements on the incidence and progression of peripheral artery disease (PAD) in patients with dysglycaemia has not been well studied. The Outcome Reduction with an Initial Glargine INtervention (ORIGIN) trial randomized participants with dysglycaemia and cardiovascular risk factors to titrated insulin glargine vs standard care, and to either 1 g of omega-3 per day or placebo. We assessed incident PAD, defined as the composite of either asymptomatic or symptomatic PAD according to the randomized interventions in the 11 119 ORIGIN participants whose baseline ankle-brachial index (ABI) was >0.9 (no PAD), and PAD progression in the 971 ORIGIN participants whose baseline ABI was ≤0.9. Hazard ratios (HR) were adjusted for confounders. During a 6.2-year follow-up period, allocation to insulin glargine vs standard care had a neutral effect on the composite of PAD incidence (HR, 0.99; 95% CI, 0.86-1.15) and progression (HR, 0.88; 95% CI, 0.63-1.22). Similar findings were noted for allocation to omega-3 vs placebo for PAD incidence (HR, 1.02; 95% CI, 0.89-1.18) and progression (HR, 0.93; 95% CI, 0.67-1.28). In this large study, neither insulin glargine nor omega-3 affected the incidence or progression of PAD.

The Role of the Microbiota in the Diabetic Peripheral Artery Disease

Vascular complications of diabetes mellitus represent a major public health problem. Although many steps forward have been made to define the causes and to find the best possible therapies, the problem remains crucial. In recent years, more and more evidences have defined a link between microbiota and the initiation, promotion, and evolution of atherosclerotic disease, even in the diabetic scenario. There is an urgency to develop the knowledge of modern medicine about the link between gut microbiota and its host's metabolic pathways, and it would be useful to understand and justify the interindividual diversity of clinical disease presentation of diabetic vascular complication even if an optimization of pharmacological treatment has been made or in the case of young patients where hypertension, dyslipidemia, and diabetes are not able to justify a very quick progress of atherosclerotic process. The aim of the present review is to gather all the best available evidence in this regard and to define a new role of the microbiota in this field, from biomarker to possible therapeutic target.

Pioglitazone: The forgotten, cost-effective cardioprotective drug for type 2 diabetes

Type 2 diabetes individuals are at high risk for macrovascular complications: myocardial infarction, stroke and cardiovascular mortality. Recent cardiovascular outcome trials have demonstrated that agents in two antidiabetic classes (SGLT2 inhibitors and GLP-1 receptor agonists) reduce major adverse cardiovascular events. However, there is strong evidence that an older and now generically available medication, the thiazolidinedione, pioglitazone, can retard the atherosclerotic process (PERISCOPE and Chicago) and reduce cardiovascular events in large randomized prospective cardiovascular outcome trials (IRIS and PROactive). Pioglitazone is a potent insulin sensitizer, preserves beta-cell function, causes durable reduction in HbA1c, corrects multiple components of metabolic syndrome and improves nonalcoholic fatty liver disease/nonalcoholic steatohepatitis. Adverse effects (weight gain, fluid retention, fractures) must be considered, but are diminished with lower doses and are arguably outweighed by these multiple benefits. With healthcare expenses attributable to diabetes increasing rapidly, this cost-effective drug requires reconsideration in the therapeutic armamentarium for the disease.

Lower extremity arterial disease in patients with diabetes: a contemporary narrative review

Lower-extremity arterial disease (LEAD) is a major endemic disease with an alarming increased prevalence worldwide. It is a common and severe condition with excess risk of major cardiovascular events and death. It also leads to a high rate of lower-limb adverse events and non-traumatic amputation. The American Diabetes Association recommends a widespread medical history and clinical examination to screen for LEAD. The ankle brachial index (ABI) is the first non-invasive tool recommended to diagnose LEAD although its variable performance in patients with diabetes. The performance of ABI is particularly affected by the presence of peripheral neuropathy, medial arterial calcification, and incompressible arteries. There is no strong evidence today to support an alternative test for LEAD diagnosis in these conditions. The management of LEAD requires a strict control of cardiovascular risk factors including diabetes, hypertension, and dyslipidaemia. The benefit of intensive versus standard glucose control on the risk of LEAD has not been clearly established. Antihypertensive, lipid-lowering, and antiplatelet agents are obviously worthfull to reduce major cardiovascular adverse events, but few randomised controlled trials (RCTs) have evaluated the benefits of these treatments in terms of LEAD and its related adverse events. Smoking cessation, physical activity, supervised walking rehabilitation and healthy diet are also crucial in LEAD management. Several advances have been achieved in endovascular and surgical revascularization procedures, with obvious improvement in LEAD management. The revascularization strategy should take into account several factors including anatomical localizations of lesions, medical history of each patients and operator experience. Further studies, especially RCTs, are needed to evaluate the interest of different therapeutic strategies on the occurrence and progression of LEAD and its related adverse events in patients with diabetes.

Peroxisome proliferator-activated receptor gamma agonists for preventing recurrent stroke and other vascular events in people with stroke or transient ischaemic attack

BACKGROUND

Peroxisome proliferator-activated receptor gamma (PPAR-γ) agonists are insulin-sensitising drugs used for the treatment of insulin resistance. In addition to lowering glucose in diabetes, these drugs may also protect against hyperlipidaemia and arteriosclerosis, which are risk factors for stroke. This is an update of a review first published in January 2014 and subsequently updated in October 2015.

OBJECTIVES

To assess the efficacy and safety of PPAR-γ agonists in the secondary prevention of stroke and related vascular events for people with stroke or transient ischaemic attack (TIA).

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register (16 May 2017), the Cochrane Central Register of Controlled Trials (CENTRAL; 2017, Issue 5), MEDLINE (1949 to 16 May 2017), Embase (1980 to 16 May 2017), CINAHL (1982 to 16 May 2017), AMED (1985 to 16 May 2017), and 11 Chinese databases (16 May 2017). In an effort to identify further published, unpublished, and ongoing trials, we searched ongoing trials registers, reference lists, and relevant conference proceedings, and contacted authors and pharmaceutical companies. We did not impose any language restrictions.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) evaluating PPAR-γ agonists versus placebo for the secondary prevention of stroke and related vascular events in people with stroke or TIA, with the outcomes of recurrent stroke, vascular events, and adverse events.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the titles and abstracts of identified records, selected studies for inclusion, extracted eligible data, cross-checked the data for accuracy, and assessed methodological quality and risk of bias. We evaluated the quality of evidence for each outcome using the GRADE approach.

MAIN RESULTS

We identified five RCTs with 5039 participants; two studies had a low risk of bias for all domains. Four studies evaluated the drug pioglitazone, and one study evaluated rosiglitazone. The participants in different studies were heterogeneous.Recurrent strokeThree studies evaluated the number of participants with recurrent stroke (4979 participants, a single study contributing 3876 of these). Peroxisome proliferator-activated receptor gamma agonists probably reduce the recurrence of stroke compared with placebo (risk ratio (RR) 0.66, 95% confidence interval (CI) 0.44 to 0.99; moderate-quality evidence).Adverse eventsEvidence that adverse events occurred more frequently in participants treated with PPAR-γ agonists when compared with placebo was uncertain due to wide confidence interval and high levels of statistical heterogeneity: risk difference 10%, 95% CI -8% to 28%; low-quality evidence).Data were available on additional composite outcomes reflecting serious vascular events (all-cause death and other major vascular events; all-cause mortality, non-fatal myocardial infarction or non-fatal stroke) from one study in 984 people. This study provided low-quality evidence that PPAR-γ agonists led to fewer events (data not meta-analysed).Vascular eventsPeroxisome proliferator-activated receptor gamma agonists given over a mean duration of 34.5 months in a single trial of 984 participants may reduce serious vascular events expressed as a composite outcome of total events of cardiovascular death, non-fatal myocardial infarction or non-fatal stroke (RR 0.73, 95% CI 0.54 to 0.99; low-quality evidence).Other outcomesOne study in 20 people measured insulin sensitivity, and one study in 40 people measured the ubiquitin-proteasome activity in carotid plaques. Our confidence in the improvements observed with PPAR-γ agonists were limited by small sample sizes and risk of bias. None of the studies reported the number of participants with disability due to vascular events or improvement in quality of life.

AUTHORS' CONCLUSIONS

Peroxisome proliferator-activated receptor gamma agonists probably reduce recurrent stroke and total events of cardiovascular death, non-fatal myocardial infarction or non-fatal stroke, and may improve insulin sensitivity and the stabilisation of carotid plaques. Their effects on adverse events are uncertain. Our conclusions should be interpreted with caution considering the small number and the quality of the included studies. Further well-designed, double-blind RCTs with large samples are required to assess the efficacy and safety of PPAR-γ agonists in the secondary prevention of stroke and related vascular events in people with stroke or TIA.

Pioglitazone Improves Left Ventricular Diastolic Function in Subjects With Diabetes

OBJECTIVE

To examine the effect of pioglitazone on myocardial insulin sensitivity and left ventricular (LV) function in patients with type 2 diabetes (T2D).

RESEARCH DESIGN AND METHODS

Twelve subjects with T2D and 12 with normal glucose tolerance received a euglycemic insulin clamp. Myocardial glucose uptake (MGU) and myocardial perfusion were measured with [18F]fluoro-2-deoxy-d-glucose and [15O]H2O positron emission tomography before and after 24 weeks of pioglitazone treatment. Myocardial function and transmitral early diastolic relation/atrial contraction (E/A) flow ratio were measured with magnetic resonance imaging.

RESULTS

Pioglitazone reduced HbA1c by 0.9%; decreased systolic and diastolic blood pressure by 7 ± 2 and 7 ± 2 mmHg, respectively (P < 0.05); and increased whole-body insulin-stimulated glucose uptake by 71% (3.4 ± 1.3 to 5.8 ± 2.1 mg/kg · min; P < 0.01) in subjects with T2D. Pioglitazone enhanced MGU by 75% (0.24 ± 0.14 to 0.42 ± 0.13 μmol/min · g; P < 0.01) and myocardial perfusion by 16% (0.95 ± 0.16 to 1.10 ± 0.25 mL/min · g; P < 0.05). Measures of diastolic function, E/A ratio (1.04 ± 0.3 to 1.25 ± 0.4) and peak LV filling rate (349 ± 107 to 433 ± 99 mL/min), both increased (P < 0.01). End-systolic volume, end-diastolic volume, peak LV ejection rate, and cardiac output trended to increase (P not significant), whereas the ejection fraction (61 ± 6 to 66 ± 7%) and stroke volume increased significantly (71 ± 20 to 80 ± 20 L/min; both P < 0.05).

CONCLUSIONS

Pioglitazone improves whole-body and myocardial insulin sensitivity, LV diastolic function, and systolic function in T2D. Improved myocardial insulin sensitivity and diastolic function are strongly correlated.

Thiazolidinedione drugs in the treatment of type 2 diabetes mellitus: past, present and future

Thiazolidinedione (TZD) drugs used in the treatment of type 2 diabetes mellitus (T2DM) have proven effective in improving insulin sensitivity, hyperglycemia, and lipid metabolism. Though well tolerated by some patients, their mechanism of action as ligands of peroxisome proliferator-activated receptors (PPARs) results in the activation of several pathways in addition to those responsible for glycemic control and lipid homeostasis. These pathways, which include those related to inflammation, bone formation, and cell proliferation, may lead to adverse health outcomes. As treatment with TZDs has been associated with adverse hepatic, cardiovascular, osteological, and carcinogenic events in some studies, the role of TZDs in the treatment of T2DM continues to be debated. At the same time, new therapeutic roles for TZDs are being investigated, with new forms and isoforms currently in the pre-clinical phase for use in the prevention and treatment of some cancers, inflammatory diseases, and other conditions. The aims of this review are to provide an overview of the mechanism(s) of action of TZDs, a review of their safety for use in the treatment of T2DM, and a perspective on their current and future therapeutic roles.

Cardiovascular Disease and Type 2 Diabetes: Has the Dawn of a New Era Arrived?

Hyperglycemia is the major risk factor for microvascular complications in patients with type 2 diabetes (T2D). However, cardiovascular disease (CVD) is the principal cause of death, and lowering HbA1c has only a modest effect on reducing CVD risk and mortality. The recently published LEADER and SUSTAIN-6 trials demonstrate that, in T2D patients with high CVD risk, the glucagon-like peptide 1 receptor agonists liraglutide and semaglutide reduce the primary major adverse cardiac events (MACE) end point (cardiovascular death, nonfatal myocardial infarction, nonfatal stroke) by 13% and 24%, respectively. The EMPA-REG OUTCOME, IRIS (subjects without diabetes), and PROactive (second principal end point) studies also demonstrated a significant reduction in cardiovascular events in T2D patients treated with empagliflozin and pioglitazone. However, the benefit of these four antidiabetes agents (liraglutide, semaglutide, empagliflozin, and pioglitazone) on the three individual MACE end points differed, suggesting that different underlying mechanisms were responsible for the reduction in cardiovascular events. Since liraglutide, semaglutide, pioglitazone, and empagliflozin similarly lower the plasma glucose concentration but appear to reduce CVD risk by different mechanisms, there emerges the intriguing possibility that, if used in combination, the effects of these antidiabetes agents may be additive or even multiplicative with regard to cardiovascular benefit.

Pioglitazone and cardiovascular risk reduction: time for a second look?

Insulin resistance, a fundamental pathophysiological abnormality in patients with type 2 diabetes, is associated with increased cardiovascular (CV) disease risk. In diabetes management, the macrovascular impact of antihyperglycemic agents that do not improve insulin sensitivity has generally been disappointing. In contrast, glucose-lowering drugs that work as insulin sensitizing agents have been postulated to reduce CV complications. The data to support this hypothesis have, however, been inconsistent. The impact of thiazolidinediones on macrovascular events is of particular interest. In this review, we discuss the results of trials reporting CV outcomes in patients treated with thiazolidinediones. We focus on the findings of the recent Insulin Resistance Intervention after Stroke trial that demonstrated a beneficial effect of pioglitazone on CV outcomes in stroke patients with insulin resistance. We discuss the Insulin Resistance Intervention after Stroke results and its implications for clinical practice. We discuss the selective use of pioglitazone as secondary prevention to reduce CV risk in insulin resistant patients.

[Antihypertensive therapy in diabetes mellitus: Guidelines of the Austrian Diabetes Association 2016]

Blood pressure lowering is one of the most important interventions for reducing the vascular complications and mortality in patients with diabetes mellitus. Recent studies indicate that the optimal blood pressure level might be in the range between 130-140 mmHg systolic and 80‒90 mmHg diastolic. Lower blood pressure levels (e.g. 120/80 mmHg) can further reduce the risk for stroke and diabetic nephropathy, but are associated with increased cardiovascular mortality. In particular, very low blood pressure levels (< 120 mmHg) should be avoided in patients with coronary heart disease or peripheral arterial disease. Most patients with diabetes mellitus need antihypertensive combination therapies, whereby ACE-inhibitors or Angiotensin-II receptor antagonists should be first line drugs.

Absence of Peripheral Pulses and Risk of Major Vascular Outcomes in Patients With Type 2 Diabetes

OBJECTIVE

The burden of vascular diseases remains substantial in patients with type 2 diabetes, requiring identification of further risk markers. We tested the absence of dorsalis pedis and posterior tibial pulses as predictors of major macrovascular and microvascular events, death, and cognitive decline in this population.

RESEARCH DESIGN AND METHODS

Data were derived from 11,120 patients with type 2 diabetes in the Action in Diabetes and Vascular Disease: Preterax and Diamicron Modified-Release Controlled Evaluation (ADVANCE) study. Absent peripheral pulses at baseline were defined as absence of at least one dorsalis pedis or posterior tibial pulse.

RESULTS

Absent compared with present peripheral pulses (n = 2,218) were associated with increased 5-year risks for major macrovascular events (hazard ratio 1.47 [95% CI 1.28-1.69], P < 0.0001), myocardial infarction (1.45 [1.13-1.87], P = 0.003), stroke (1.57 [1.23-2.00], P = 0.0003), cardiovascular death (1.61 [1.33-1.95], P < 0.0001), heart failure (1.49 [1.21-1.84], P = 0.0002), all-cause mortality (1.48 [1.29-1.71], P < 0.0001), major microvascular events (1.17 [1.00-1.36], P = 0.04), nephropathy (1.24 [1.00-1.54], P = 0.04), end-stage renal disease or renal death (2.04 [1.12-3.70], P = 0.02), and peripheral neuropathy (1.13 [1.05-1.21], P = 0.0008) after multiple adjustment. Participants with absent dorsalis pedis or posterior tibial pulses had comparable hazard ratios. Risks increased proportionally with the number of absent peripheral pulses, with the highest risks observed in patients with three or four absent pulses. Every additional absent pulse increases the risk of all outcomes.

CONCLUSIONS

Absent dorsalis pedis and/or posterior tibial pulses are independent predictors of major vascular outcomes in patients with type 2 diabetes. These simple clinical indicators should be used to improve risk stratification and treatment of these patients.

Retrospective study of the evolution of the incidence of non-traumatic lower-extremity amputations (2007-2013) and risk factors of reamputation

AIM

Describe the incidence of non-traumatic amputation in a Spain region and identify the risk factors associated with the level of amputation and reamputation.

METHODS

Retrospective study on non-traumatic lower-extremity amputees in a Spanish region between 2007 and 2013. A descriptive, bivariate and multivariate analysis was performed using bivariate logistic regression. Statistical significance p≤0.05, SPSS V.21.

RESULTS

495 amputations were carried out in 353 patients. 81.0% (n=286) were men, mean age 68.7±10.8 years. The most frequent levels of amputation were digital (45.9%) and above-knee (40.5%). About 30% of the patients were reamputated. The multivariate analysis revealed that the factors independently related to the need for a minor lower-extremity amputation were DM [OR 3.79 (CI 95% 2.0-7.27)], foot ulcer [OR 5.82 (CI 95% 2.24-15.11)] and previous ipsilateral amputation [OR 3.19 (CI 95% 1.21-8.42)]. The risk factors independently related to the need for reamputation were DM [OR 2.21 (CI95% 1.09-4.49)], smoking [OR 2.45 (CI95% 1.33-4.50)] and previous revascularization [OR 2.75 (CI95% 1.57-4.83)].

CONCLUSIONS

Determining the incidence of amputations in diabetic patients as an indicator of quality makes it possible for health services to be evaluated. In patients with DM the most common reamputations are minor and ipsilateral.

The Role of PPARγ in Cardiovascular Diseases

The peroxisome proliferator-activated receptors (PPAR) belong to the nuclear superfamily of ligand-activated transcription factors. PPARγ acts as a nutrient sensor that regulates several homeostatic functions. Its disruption can lead to vascular pathologies, disorders of fatty acid/lipid metabolism and insulin resistance. PPARγ can modulate several signaling pathways connected with blood pressure regulation. Firstly, it affects the insulin signaling pathway and endothelial dysfunction by modulation of expression and/or phosphorylation of signaling molecules through the PI3K/Akt/eNOS or MAPK/ET-1 pathways. Secondly, it can modulate gene expression of the renin- angiotensin system – cascade proteins, which potentially slow down the progression of atherosclerosis and hypertension. Thirdly, it can modulate oxidative stress response either directly through PPAR or indirectly through Nrf2 activation. In this context, activation and functioning of PPARγ is very important in the regulation of several disorders such as diabetes mellitus, hypertension and/or metabolic syndrome.

Presentations of major peripheral arterial disease and risk of major outcomes in patients with type 2 diabetes: results from the ADVANCE-ON study

Background

Peripheral arterial disease (PAD) is known to be associated with high cardiovascular risk, but the individual impact of PAD presentations on risk of macrovascular and microvascular events has not been reliably compared in patients with type 2 diabetes. We aimed to evaluate the impact of major PAD, and its different presentations, on the 10-year risk of death, major macrovascular events, and major clinical microvascular events in these patients.

Methods

Participants in the action in diabetes and vascular disease: PreterAx and DiamicroN modified-release controlled evaluation (ADVANCE) trial and the ADVANCE-ON post-trial study were followed for a median of 5.0 (in-trial), 5.4 (post-trial), and 9.9 (overall) years. Major PAD at baseline was subdivided into lower-extremity chronic ulceration or amputation secondary to vascular disease and history of peripheral revascularization by angioplasty or surgery.

Results

Among 11,140 participants, 516 (4.6 %) had major PAD at baseline: 300 (2.7 %) had lower-extremity ulceration or amputation alone, 190 (1.7 %) had peripheral revascularization alone, and 26 (0.2 %) had both presentations. All-cause mortality, major macrovascular events, and major clinical microvascular events occurred in 2265 (20.3 %), 2166 (19.4 %), and 807 (7.2 %) participants, respectively. Compared to those without PAD, patients with major PAD had increased rates of all-cause mortality (HR 1.35, 95 % CI 1.15–1.60, p = 0.0004), and major macrovascular events (1.47 [1.23–1.75], p < 0.0001), after multiple adjustments for region of origin, cardiovascular risk factors and treatments, peripheral neuropathy markers, and randomized treatments. We have also observed a trend toward an association of baseline PAD with risk of major clinical microvascular events [1.31 (0.96–1.78), p = 0.09]. These associations were comparable for patients with a lower-extremity ulceration or amputation and for those with a history of peripheral revascularization. Furthermore, the risk of retinal photocoagulation or blindness, but not renal events, increased in patients with lower-extremity ulceration or amputation [1.53 (1.01–2.30), p = 0.04].

Conclusions

Lower-extremity ulceration or amputation, and peripheral revascularization both increased the risks of death and cardiovascular events, but only lower-extremity ulceration or amputation increased the risk of severe retinopathy in patients with type 2 diabetes. Screening for major PAD and its management remain crucial for cardiovascular prevention in patients with type 2 diabetes (ClinicalTrials.gov number, NCT00949286).

Electronic supplementary material

The online version of this article (doi:10.1186/s12933-016-0446-x) contains supplementary material, which is available to authorized users.

Pioglitazone (Actos) and bladder cancer: Legal system triumphs over the evidence

In preclinical studies, pioglitazone was associated with bladder cancer in male rats (but not in female rats, mice dogs or monkeys). Because of this association, the Federal Drug Administration requested a large 10year epidemiological study to evaluate whether there was an association between bladder cancer and exposure to pioglitazone in patients. A 5-year interim report published in 2011 showed no significant association between ever vs never exposure to the drug but a significant association in patients exposed to pioglitazone for >2years. Importantly, the final 10year report did not confirm the 5year interim report finding no association between bladder cancer and pioglitazone, even after >4years of exposure to the drug. However, as would be expected, following the 5-year interim report, many epidemiological studies were carried out and civil litigation lawsuits began to be filed. Of the 23 epidemiological studies that have been published to date, 18 showed no association between bladder cancer and pioglitazone (5 with a combination of rosiglitazone and pioglitazone). Of the five that did show a significant association with pioglitazone, three could not be confirmed in the same population and in one of them there were significantly more risk factors for bladder cancer in the patients exposed to pioglitazone. In the fourth one, a significant association became non-significant when patients >79years were included. In the fifth one, detection bias was a major flaw. Currently, >11,000 legal cases have been filed, many of which claim emotional distress due to the fear of bladder cancer. To limit their legal costs, the pharmaceutical company has established a 2.4 billion dollar settlement pool. So much for evidence-based medicine.

Revitalization of pioglitazone: the optimum agent to be combined with a sodium-glucose co-transporter-2 inhibitor

The recently completed EMPA-REG study showed that empagliflozin significantly decreased the major adverse cardiac events (MACE) endpoint, which comprised cardiovascular death, non-fatal myocardial infarction (MI) and stroke, in patients with high-risk type 2 diabetes (T2DM), primarily through a reduction in cardiovascular death, without a significant decrease in either MI or stroke. In the PROactive study, pioglitazone decreased the MACE endpoint by a similar degree to that observed in the EMPA-REG study, through a marked reduction in both recurrent MI and stroke and a modest reduction in cardiovascular death. These observations suggest that pioglitazone might be an ideal agent to combine with empagliflozin to further reduce cardiovascular events in patients with high-risk diabetes as empagliflozin also promotes salt/water loss and would be expected to offset any fluid retention associated with pioglitazone therapy. In the present paper, we provide an overview of the potential benefits of combined pioglitazone/empagliflozin therapy to prevent cardiovascular events in patients with T2DM.

Glucose-lowering therapy in type 2 diabetes. New hope after the EMPA-REG outcome trial

Prevention of cardiovascular morbidity and mortality remains the key factor in the treatment of type 2 diabetes (T2DM). In the early phase of T2DM, multifactorial intervention is mandatory and glucose levels should be near normal, in particular in younger patients presenting with the highest cardiovascular risk. Anti-diabetic drugs without any risk for hypoglycaemia should be preferred in order to reduce clinical inertia and increase the long-term adherence to the treatment. In patients already presenting with cardiovascular disease, the best outcome may be expected with the triple oral therapy of metformin, pioglitazone, and empagliflozin, although a controlled prospective study versus insulin therapy is needed to confirm the expectation.

Ten-year observational follow-up of PROactive: a randomized cardiovascular outcomes trial evaluating pioglitazone in type 2 diabetes

AIMS

To conduct a 10-year, observational follow-up of patients completing PROactive to investigate whether trends of cardiovascular benefit with pioglitazone and imbalances in specific malignancies persisted over time.

METHODS

Macrovascular endpoints and malignancies were compared based on original randomization to pioglitazone or placebo and 'any' versus 'no' pioglitazone use for bladder and prostate cancer.

RESULTS

Of 4873 patients completing the PROactive trial, 74% entered the follow-up. During follow-up (mean 7.8 years), there were no statistically significant differences in the primary [all-cause mortality, myocardial infarction (MI), cardiac intervention, stroke, major leg amputation, leg revascularization] or main secondary (death, MI, stroke) endpoints for subjects originally randomized to pioglitazone and placebo, except for leg amputations during follow-up [4.1% pioglitazone, 5.6% placebo; hazard ratio 0.74, 95% confidence interval (CI) 0.55-0.99; p = 0.046]. During follow-up, the incidence of total malignancies was similar between groups; bladder cancer was reported in 0.8% of patients (n = 14) in the pioglitazone versus 1.2% (n = 21) in the placebo group [relative risk (RR) 0.65, 95% CI 0.33-1.28], and prostate cancer was reported in 44 men (3.7%) in the pioglitazone versus 29 men (2.5%) in the placebo group (RR 1.47, 95% CI 0.93-2.34).

CONCLUSIONS

The trends of macrovascular benefits of pioglitazone compared with placebo during PROactive did not persist in the absence of continued pioglitazone during this 10-year follow-up. Trends of decreased bladder cancer and increased prostate cancer were observed in the pioglitazone group during follow-up; however, these imbalances should be interpreted with caution because of the limitations of the observational study design.

Peroxisome proliferator-activated receptor gamma agonists for preventing recurrent stroke and other vascular events in patients with stroke or transient ischaemic attack

BACKGROUND

Peroxisome proliferator-activated receptor gamma (PPAR-γ) agonists are insulin-sensitising drugs used for the treatment of insulin resistance. In addition to lowering glucose in diabetes, these drugs may also protect against hyperlipidaemia and arteriosclerosis, which are risk factors for stroke.

OBJECTIVES

To assess the efficacy and safety of PPAR-γ agonists in the secondary prevention of stroke and related vascular events for people with stroke or transient ischaemic attack (TIA).

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register (July 2015), the Cochrane Central Register of Controlled Trials (CENTRAL 2015, Issue 6), MEDLINE (1949 to July 2015), EMBASE (1980 to July 2015), CINAHL (1982 to July 2015), AMED (1985 to July 2015) and 11 Chinese databases (July 2015). In an effort to identify further published, unpublished and ongoing trials we searched ongoing trials registers, reference lists and relevant conference proceedings, and contacted authors and pharmaceutical companies. We did not impose any language restrictions.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) evaluating PPAR-γ agonists versus placebo for the secondary prevention of stroke and related vascular events in people with stroke or TIA, with the outcomes of recurrent stroke, vascular events and adverse events.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the titles and abstracts of identified records, selected studies for inclusion, extracted eligible data, cross-checked the data for accuracy, and assessed methodological quality and risk of bias.

MAIN RESULTS

We identified four eligible studies with 1163 participants; only one study had a low risk of bias for all domains. Three studies evaluated the drug pioglitazone and one study evaluated rosiglitazone. The participants in different studies were heterogeneous. The number of participants with recurrent stroke was evaluated in two studies, where PPAR-γ agonists reduced the recurrence of stroke compared with placebo (risk ratio (RR) 0.52, 95% confidence interval (CI) 0.34 to 0.80). PPAR-γ agonists given over a mean duration of 34.5 months in a single trial were found to reduce a composite outcome of total events of cardiovascular death, non-fatal myocardial infarction or non-fatal stroke (RR 0.73, 95% CI 0.54 to 0.99). Data on additional composite outcomes reflecting serious adverse events (all-cause death and other major vascular events; all-cause mortality, non-fatal myocardial infarction or non-fatal stroke) were similar although the confidence intervals were wider and the effects were not statistically significant. In addition, two studies respectively measured insulin sensitivity and the ubiquitin-proteasome activity in carotid plaques. These results were significantly improved by PPAR-γ agonists in comparison with placebo. None of the studies reported the number of participants with disability due to vascular events or improvement in quality of life. Three RCTs reported information about adverse events. Frequent adverse events included oedema, cardiac failure and anaemia. Evidence that adverse events occurred more frequently in participants treated with PPAR-γ agonists when compared with placebo was imprecise and inconsistent (risk difference (RD) 10%, 95% CI -8% to 28%, I² = 86%).

AUTHORS' CONCLUSIONS

PPAR-γ agonists appear to reduce recurrent stroke and total events of cardiovascular death, non-fatal myocardial infarction or non-fatal stroke, and improve insulin sensitivity and the stabilisation of carotid plaques. There is evidence of limited quality that they are well tolerated. However, the conclusions should be interpreted with caution considering the small number and the quality of the included studies. In future, well-designed, double-blind RCTs with large samples are required to assess the efficacy and safety of PPAR-γ agonists in the secondary prevention of stroke and related vascular events in people with stroke or TIA.

Impact of glucose-lowering drugs on cardiovascular disease in type 2 diabetes

Type 2 diabetes mellitus (T2DM) is characterized by multiple pathophysiologic abnormalities. With time, multiple glucose-lowering medications are commonly required to reduce and maintain plasma glucose concentrations within the normal range. Type 2 diabetes mellitus individuals also are at a very high risk for microvascular complications and the incidence of heart attack and stroke is increased two- to three-fold compared with non-diabetic individuals. Therefore, when selecting medications to normalize glucose levels in T2DM patients, it is important that the agent not aggravate, and ideally even improve, cardiovascular risk factors (CVRFs) and reduce cardiovascular morbidity and mortality. In this review, we examine the effect of oral (metformin, sulfonylureas, meglitinides, thiazolidinediones, DPP4 inhibitors, SGLT2 inhibitors, and α-glucosidase inhibitors) and injectable (glucagon-like peptide-1 receptor agonists and insulin) glucose-lowering drugs on established CVRFs and long-term studies of cardiovascular outcomes. Firm evidence that in T2DM cardiovascular disease can be reversed or prevented by improving glycaemic control is still incomplete and must await large, long-term clinical trials in patients at low risk using modern treatment strategies, i.e., drug combinations designed to maximize HbA1c reduction while minimizing hypoglycaemia and excessive weight gain.

Comparison of lower extremity atherosclerosis in diabetic and non-diabetic patients using multidetector computed tomography

Background

Lower extremity atherosclerosis (LEA) is among the most serious diabetic complications and leads to non-traumatic amputations. The recently developed dual-source CT (DSCT) and 320- multidetector computed tomography (MDCT) may help to detect plaques more precisely. The aim of our study was to evaluate the differences in LEA between diabetic and non-diabetic patients using MDCT angiography.

Methods

DSCT and 320-MDCT angiographies of the lower extremities were performed in 161 patients (60 diabetic and 101 non-diabetic). The plaque type, distribution, shape and obstructive natures were compared.

Results

Compared with non-diabetic patients, diabetic patients had higher peripheral neuropathy, history of cerebrovasuclar infarction and hypertension rates. A total of 2898 vascular segments were included in the analysis. Plaque and stenosis were detected in 681 segments in 60 diabetic patients (63.1%) and 854 segments in 101 non-diabetic patients (46.9%; p <0.05). Regarding these plaques, diabetic patients had a higher incidence of mixed plaques (34.2% vs. 27.1% for non-diabetic patients). An increased moderate stenosis rate and decreased occlusion rate were observed in diabetic patients relative to non-diabetic patients (35.8% vs. 28.3%; and 6.6% vs. 11.4%; respectively). In diabetic patients, 362 (53.2%) plaques were detected in the distal lower leg segments, whereas in non-diabetic patients, 551 (64.5%) plaques were found in the proximal upper leg segments. The type IV plaque shape, in which the full lumen was involved, was detected more frequently in diabetic patients than in non-diabetic patients (13.1% vs. 8.2%).

Conclusion

Diabetes is associated with a higher incidence of plaque, increased incidence of mixed plaques, moderate stenosis and localisation primarily in the distal lower leg segments. The advanced and non-invasive MDCT could be used for routine preoperative evaluations of LEA.

Optimal therapy of type 2 diabetes: a controversial challenge

Type 2 diabetes mellitus (T2DM) is one of the most common chronic disorders in older adults and the number of elderly diabetic subjects is growing worldwide. Nonetheless, the diagnosis of T2DM in elderly population is often missed or delayed until an acute metabolic emergency occurs. Accumulating evidence suggests that both aging and environmental factors contribute to the high prevalence of diabetes in the elderly. Clinical management of T2DM in elderly subjects presents unique challenges because of the multifaceted geriatric scenario. Diabetes significantly lowers the chances of "successful" aging, notably it increases functional limitations and impairs quality of life. In this regard, older diabetic patients have a high burden of comorbidities, diabetes-related complications, physical disability, cognitive impairment and malnutrition, and they are more susceptible to the complications of dysglycemia and polypharmacy. Several national and international organizations have delivered guidelines to implement optimal therapy in older diabetic patients based on individualized treatment goals. This means appreciation of the heterogeneity of the disease as generated by life expectancy, functional reserve, social support, as well as personal preference. This paper will review current treatments for achieving glycemic targets in elderly diabetic patients, and discuss the potential role of emerging treatments in this patient population.

Pioglitazone inhibits HIF-1α-dependent angiogenesis in rats by paracrine and direct effects on endothelial cells

Abstract

Pioglitazone was associated with increased hazard for surgical or percutaneous lower extremity revascularization in patients with diabetes in a large clinical trial, but this clinical finding has not been adequately explored in animal models. We hypothesized that pioglitazone would decrease hypoxia-inducible factor 1α (HIF-1α)-dependent angiogenesis in rat ischemic hindlimb models by altering mitochondrial-derived signals supporting HIF-1α activation. We tested oral pioglitazone (10 mg/kg/day) versus placebo in two cohorts of rats with hindlimb ischemia (normal Sprague–Dawley rats and insulin-resistant JCR:La-cp rats), and evaluated direct and paracrine effects of pioglitazone on angiogenesis in vitro using human skeletal muscle and endothelial cells. Pioglitazone treatment was associated with reductions in limb perfusion at 2 weeks measured by contrast-enhanced ultrasound and Tc^99m-Sestamibi SPECT-CT. Ischemic muscle capillary density was also reduced by pioglitazone. HIF-1α and vascular endothelial growth factor (VEGF) expression in ischemic muscle were also reduced by pioglitazone. In vitro, pioglitazone's effects on both skeletal muscle cells and microvascular endothelial cells were associated with a decrease in autocrine and paracrine angiogenesis measured by matrigel assay, decreased HIF-1α expression and activation, as well as increases in both mitochondrial reactive oxygen species and α-ketoglutarate, both mitochondria-derived signals which promote HIF-1α degradation. We conclude that pioglitazone is associated with decreased ischemic limb perfusion and capillary density in relevant rat models of hindlimb ischemia, and these effects are mediated by mitochondria-dependent reductions in HIF-1α-dependent angiogenesis.

Key messages

Pioglitazone inhibits angiogenesis in rats with and without insulin resistance.

Pioglitazone inhibits HIF-1α by inhibiting mitochondrial stabilization of HIF-1.

Pioglitazone inhibits both autocrine and paracrine angiogenesis.

Inhibition of angiogenesis may explain unexpected results of a pioglitazone human clinical trial.

Electronic supplementary material

The online version of this article (doi:10.1007/s00109-013-1115-0) contains supplementary material, which is available to authorized users.

Peroxisome proliferator-activated receptor gamma agonists for preventing recurrent stroke and other vascular events in patients with stroke or transient ischaemic attack

BACKGROUND

Peroxisome proliferator-activated receptor gamma (PPAR-γ) agonists are insulin-sensitising drugs used for the treatment of insulin resistance. In addition to lowing glucose in diabetes, these drugs may also protect against hyperlipidaemia and arteriosclerosis, which are risk factors for stroke.

OBJECTIVES

To assess the efficacy and safety of PPAR-γ agonists in the secondary prevention of stroke and related vascular events for people with stroke or transient ischaemic attack (TIA).

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register (August 2013), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2013, Issue 9), MEDLINE (1949 to October 2013), EMBASE (1980 to October 2013), CINAHL (1982 to October 2013), AMED (1985 to October 2013) and 11 Chinese databases (October 2013). In an effort to identify further published, unpublished and ongoing trials we searched ongoing trials registers, reference lists and relevant conference proceedings, and contacted authors and pharmaceutical companies. There were no language restrictions.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) evaluating PPAR-γ agonists versus placebo for the secondary prevention of stroke and related vascular events in people with stroke or TIA, with the outcomes of recurrent stroke, vascular events and adverse events.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the titles and abstracts of identified records, selected studies for inclusion, extracted eligible data, cross-checked the data for accuracy and assessed the methodological quality.

MAIN RESULTS

We identified four eligible studies with 1163 participants; only one study had a low risk of bias for all domains. The participants in different studies were heterogeneous. The number of participants with recurrent stroke was evaluated in two studies, where PPAR-γ agonists reduced the recurrence of stroke compared with placebo (risk ratio (RR) 0.52, 95% confidence interval (CI) 0.34 to 0.80). PPAR-γ agonists given over a mean duration of 34.5 months in a single trial were found to reduce a composite outcome of total events of cardiovascular death, non-fatal myocardial infarction or non-fatal stroke (RR 0.73, 95% CI 0.54 to 0.99). Data on additional composite outcomes reflecting serious adverse events (all-cause death and other major vascular events; all-cause mortality, non-fatal myocardial infarction or non-fatal stroke) were similar although the confidence intervals were wider and the effects were not statistically significant. In addition, two studies respectively measured insulin sensitivity and the ubiquitin-proteasome activity in carotid plaques with significant differences in these outcomes between PPAR-γ agonists and placebo. None of the studies reported the number of participants with disability due to vascular events or improvement in quality of life. Three RCTs reported information about adverse events. Frequent adverse events included oedema, cardiac failure and anaemia. Evidence that adverse events occurred more frequently in participants treated with PPAR-γ agonists when compared with placebo was imprecise and inconsistent (risk difference (RD) 10%, 95% CI -8% to 28%, I² = 86%).

AUTHORS' CONCLUSIONS

PPAR-γ agonists were demonstrated to reduce recurrent stroke and total events of cardiovascular death, non-fatal myocardial infarction or non-fatal stroke, and improve insulin sensitivity and the stabilisation of carotid plaques. There is evidence of limited quality that they are well-tolerated. However, the conclusions should be interpreted with caution considering the small number and the quality of the included studies. In future, well-designed, double-blind RCTs with large samples are required to test the efficacy and safety of PPAR-γ agonists in the secondary prevention of stroke and related vascular events in people with stroke or TIA.

Observational follow-up of the PROactive study: a 6-year update

AIMS

The PROactive study investigated pioglitazone for secondary prevention of macrovascular events in type 2 diabetes mellitus. Pioglitazone showed a 10% (non-significant) relative risk (RR) reduction for the primary composite endpoint and a significant 16% reduction for the main secondary endpoint (death, myocardial infarction, stroke) after a mean 34.5 months. There was no difference in cumulative malignancy incidence, but an imbalance in bladder malignancies (pioglitazone 14, placebo 5). We present a pre-specified 6-year interim analysis of a 10-year observational follow-up.

METHODS

Any patient completing PROactive was eligible. No study treatments were provided. A Cox proportional hazard model compared non-adjudicated macrovascular events (same endpoints as PROactive excluding acute coronary syndrome) based on original randomization. Malignancies were compared using conventional RR ratios.

RESULTS

Of 5238 randomized patients, 3599 (74%) entered the follow-up. For the follow-up (mean 5.8 years) or combined double-blind and follow-up periods (≤9.5 years, mean 8.7), there were no statistically significant differences in primary or main secondary endpoints. For the combined period, a similar percentage of patients had any diagnosed malignancy (RR = 1.05, 95% CI [0.89, 1.24]) or bladder malignancy (RR = 1.06, 95% CI [0.59, 1.89]) in the pioglitazone and placebo groups. There were fewer cases of bladder malignancy with pioglitazone (15 [0.6%] vs. 19 [0.7%] for placebo) for the combined period when events diagnosed in the first 365 days were excluded, and fewer cases for the follow-up period alone (10 [0.5%] vs. 17 [1.0%] for placebo). Further analyses of pioglitazone use (including use during follow-up) found no significant difference in bladder malignancies between any and no pioglitazone use for the combined period.

CONCLUSIONS

These data suggest that improved macrovascular outcomes seen with pioglitazone subside without continued pioglitazone treatment. The double-blind period bladder cancer imbalance did not persist in follow-up.

Favorable effects of insulin sensitizers pertinent to peripheral arterial disease in type 2 diabetes: results from the Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) trial

OBJECTIVE

The aim of this manuscript was to report the risk of incident peripheral arterial disease (PAD) in a large randomized clinical trial that enrolled participants with stable coronary artery disease and type 2 diabetes and compare the risk between assigned treatment arms.

RESEARCH DESIGN AND METHODS

The Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) trial randomly assigned participants to insulin sensitization (IS) therapy versus insulin-providing (IP) therapy for glycemic control. Results showed similar 5-year mortality in the two glycemic treatment arms. In secondary analyses reported here, we examine the effects of treatment assignment on the incidence of PAD. A total of 1,479 BARI 2D participants with normal ankle-brachial index (ABI) (0.91-1.30) were eligible for analysis. The following PAD-related outcomes are evaluated in this article: new low ABI≤0.9, a lower-extremity revascularization, lower-extremity amputation, and a composite of the three outcomes.

RESULTS

During an average 4.6 years of follow-up, 303 participants experienced one or more of the outcomes listed above. Incidence of the composite outcome was significantly lower among participants assigned to IS therapy than those assigned to IP therapy (16.9 vs. 24.1%; P<0.001). The difference was significant in time-to-event analysis (hazard ratio 0.66 [95% CI 0.51-0.83], P<0.001) and remained significant after adjustment for in-trial HbA1c (0.76 [0.59-0.96], P=0.02).

CONCLUSIONS

In participants with type 2 diabetes who are free from PAD, a glycemic control strategy of insulin sensitization may be the preferred therapeutic strategy to reduce the incidence of PAD and subsequent outcomes.

[Antihypertensive therapy in diabetes mellitus - 2012 guidelines of the Austrian Diabetes Association]

Blood pressure lowering is one of the most important interventions for reducing the vascular complications and mortality in patients with diabetes mellitus. Recent studies indicate that the optimal blood pressure level might be in the range between 130-135 mmHg systolic and 80 mmHg diastolic. Lower blood pressure levels (e.g. 120/80 mmHg) can further reduce the risk for stroke and diabetic nephropathy, but are associated with increased cardiovascular mortality. In particular very low blood pressure levels (< 120 mmHg) should be avoided in patients with coronary heart disease or peripheral arterial disease. Most patients with diabetes mellitus need antihypertensive combination therapies, whereby ACE-inhibitors or Angiotensin-II receptor antagonists should be first line drugs.

PPAR agonists for the treatment of cardiovascular disease in patients with diabetes

Diabetes is a complex disease defined by hyperglycaemia; however, strong associations with abdominal obesity, hypertension and dyslipidaemia contribute to the high risk of cardiovascular disease. Although aggressive glycaemic control reduces microvascular complications, the evidence for macrovascular complications is less certain. The theoretical benefits of the mode of action of peroxisome proliferator-activated receptor (PPAR) agonists are clear. In clinical practice, PPAR-α agonists such as fibrates improve dyslipidaemia, while PPAR-γ agonists such as thiazolidinediones improve insulin resistance and diabetes control. However, although these agents are traditionally classed according to their target, they have different and sometimes conflicting clinical benefit and adverse event profiles. It is speculated that this is because of differing properties and specificities for the PPAR receptors (each of which targets specific genes). This is most obvious in the impact on cardiovascular outcomes--in clinical trials pioglitazone appeared to reduce cardiovascular events, whereas rosiglitazone potentially increased the risk of myocardial infarction. The development of a dual PPAR-α/γ agonist may prove beneficial in effectively managing glycaemic control and improving dyslipidaemia in patients with type 2 diabetes. Yet, development of agents such as muraglitazar and tesaglitazar has been hindered by various serious adverse events. Aleglitazar, a balanced dual PPAR-α/γ agonist, is currently the most advanced in clinical development and has shown promising results in phase II clinical trials with beneficial effects on glucose and lipid variables. A phase III study, ALECARDIO, is ongoing and will establish whether improvements in laboratory test profiles translate into an improvement in cardiovascular outcomes.

Outcomes and lessons from the PROactive study

Beyond improvement of glucose control, thiazolidinediones exert pleiotropic effects, which may contribute to some cardiovascular protection. PROactive ("PROspective pioglitAzone Clinical Trial In macroVascular Events") has provided valuable, although controversial, information on the impact of pioglitazone on cardiovascular outcomes in a high-risk population of patients with type 2 diabetes and established macrovascular disease. Since 2005, there has been much debate on the relative value of the statistically non-significant 10% reduction in the quite challenging primary composite endpoint (combining cardiovascular disease-driven and procedural events in all vascular beds) versus the statistically significant 16% decrease in the more robust and conventional main secondary endpoint (all-cause mortality, myocardial infarction, and stroke) observed with pioglitazone. Revisiting PROactive deserves much interest following the report of inconclusive results on cardiovascular efficacy and safety of rosiglitazone in RECORD, the withdrawal (limitation) of rosiglitazone because of cardiovascular safety concern, the recent publication of a statement positioning pioglitazone in type 2 diabetes and the near availability of cheaper generics of pioglitazone. Although subanalyses may have more limited value from a statistical viewpoint, they nonetheless can provide valuable information on the drug efficacy/safety profile and clinical insights into which patients might benefit most (in terms of cardiovascular outcomes) from pioglitazone therapy.

Quality of life in elderly diabetic patients with peripheral arterial disease

AIM

To study the impact of peripheral arterial disease (PAD) on quality of life and functional status in Egyptian elderly diabetic patients.

METHODS

This case-control study included 90 non-demented patients aged 60 years and older. Quality of life assessment was carried out using the Short Form 36 health survey (SF-36), Arterial duplex for diagnosis of peripheral arterial disease; Mini-Mental State Examination, Geriatric Depression Scale, Activity of Daily Living and Instrumental Activity of Daily Living were used.

RESULTS

SF-36 domains (except emotional well-being) were significantly affected in diabetic patients with PAD compared with the diabetic patients without PAD. Most of functional assessment items were significantly affected in diabetic patients with PAD compared with diabetic patients without PAD. Increasing PAD severity and presence of PAD symptoms had a significant negative impact on SF-36 scores. Among diabetic complications in PAD patients, cardiovascular disease or stroke significantly affected quality of life.

CONCLUSION

PAD significantly affects quality of life and functional status in elderly diabetic patients.

Thiazolidinediones and cardiovascular risk - a question of balance

BACKGROUND

Several recent meta-analyses of adverse event data from randomized controlled trials with rosiglitazone reveal a possible association between this thiazolidinedione and an increased risk of ischemic myocardial events. This has led to debate on the overall clinical benefit of glitazone therapy for type 2 diabetes. Pioglitazone, on the other hand, has the most extensive cardiovascular outcomes database of all current glucose-lowering therapies, including a large prospective randomized controlled trial designed specifically to assess cardiovascular outcomes (PROactive). The available data suggest that pioglitazone is associated with a reduction in macrovascular risk.

AIMS

In this review, we highlight some of the key factors that need to be considered when assessing the net clinical benefit of thiazolidinediones, focussing on both class effects and those specific to either rosiglitazone or pioglitazone.

RESULTS

For pioglitazone there appears to be no increase in the risk of overall macrovascular events and no adverse clinical consequences of developing signs of heart failure. Furthermore, there is good evidence of significant benefit regarding the composite of death, MI or stroke.

CONCLUSION

The benefits seen with pioglitazone appear to outweigh the risks.