Plasminogen activator inhibitor activity in diabetic and nondiabetic survivors of myocardial infarction

Systemic and local factors associated with reduced thrombolysis in myocardial infarction flow in ST-segment elevation myocardial infarction patients with plaque erosion detected by intravascular optical coherence tomography

Local factors of plaque rupture (e.g. lipid burden) are related to preprocedural thrombolysis in myocardial infarction (TIMI) flow grade during primary percutaneous coronary intervention (PCI). However, the pathological mechanism differs between plaque erosion and rupture. We aimed to identify the factors associated with reduced TIMI flow in plaque erosion. A total of 329 ST-segment elevation myocardial infarction (STEMI) patients with optical coherence tomography (OCT) identified plaque erosion were divided into 2 groups by preprocedural TIMI flow grade [TIMI 0-1 group (n = 219) and TIMI 2-3 group (n = 110)]. Patients in TIMI 0-1 group were older (age > 50 years, 68.5% vs. 51.8%, P = 0.003), and had more diabetes mellitus (18.3% vs. 8.2%, P = 0.015). Plaque erosion with TIMI flow 0-1 was less frequently located in the left anterior descending artery (LAD, 58.4% vs. 72.7%, P = 0.011), but more frequently located in the right coronary artery (RCA, 34.2% vs. 7.3%, P = 0.001) than those with TIMI flow 2-3. TIMI 0-1 group had more lipid plaques (53.9% vs. 41.8%, P = 0.039), macrophage accumulation (59.8% vs. 41.8%, P = 0.002), and calcification (34.2% vs. 21.8%, P = 0.020). In the multivariable analysis, age > 50 years, diabetes mellitus, RCA location, and macrophage accumulation were the independent predictors of reduced TIMI flow grade in STEMI patients with plaque erosion. Systemic factors (older age and diabetes mellitus) and local factors (RCA location and macrophage accumulation) were independently associated with reduced coronary flow in STEMI patients with plaque erosion. CLINICAL TRIAL REGISTRATION : ClinicalTrials.gov NCT03084991 May 17, 2017 (retrospectively registered).

Aspirin for Primary Prevention of Cardiovascular Disease in Diabetes: a Review of the Evidence

PURPOSE OF REVIEW

People with diabetes are at a higher risk of atherosclerotic cardiovascular disease (ASCVD) compared with those without diabetes. Though aspirin has been shown to have an overall net clinical benefit when used for secondary prevention of ASCVD in people with and without diabetes, the evidence for primary prevention, especially in those with diabetes, remains inconsistent. In this article, we review the latest studies examining the risks and benefits of aspirin use for primary prevention of ASCVD in adults with diabetes, discuss key aspects in assessing the risk-benefit ratio of aspirin use for primary prevention of ASCVD, and summarize current guidelines from professional societies on aspirin use for primary prevention in adults with diabetes.

RECENT FINDINGS

In the general population, past studies have shown no difference in the beneficial effect of aspirin for primary cardiovascular disease prevention by diabetes status. However, several randomized controlled studies and meta-analyses in adults with diabetes have shown lack of net clinical benefit of aspirin use for primary prevention of ASCVD. The recent ASCEND trial documented cardiovascular benefit of aspirin for primary prevention in adults with diabetes but suggested that the increased risk of bleeding may outweigh the cardiovascular benefit. The decision to initiate aspirin for primary prevention of ASCVD must be considered carefully on an individual basis to balance the cardiovascular benefit and bleeding risk in all patients, especially those with diabetes. A multifactorial approach that focuses on managing ASCVD risk factors such as hypertension, dyslipidemia, dysglycemia, and smoking is recommended in all patients. More research is needed to identify subgroups of people with diabetes who are more likely to benefit from aspirin use for primary prevention of ASCVD and develop better antithrombotic strategies that shift the risk-benefit balance toward an overall net clinical benefit.

PPAR-γ receptor agonists-a review of their role in diabetic management in Trinidad and Tobago

The PPAR-γ receptor agonists, as a relatively new and perhaps still not very widely used class of antidiabetic agent in the Caribbean and particularly the Trinidadian context, possess pharmacologic properties that certainly have been shown to have impact on many of the inflammatory, metabolic, biochemical and structural macrovascular aberrations that occur in the type 2 diabetic. Activation of PPAR(gamma) nuclear receptors regulates the transcription of insulin-responsive genes involved in the control of glucose production, transport, and utilization. PPAR(gamma)-responsive genes also participate in the regulation of fatty acid metabolism, an important contributory pathogenic factor in this subset of patients. The unique mode of action of this class of therapeutic agent addresses a range of anomalies occurring at the cellular and sub-cellular level that are injurious to the diabetic. My aim in addressing the issue of the potential impact of PPAR-γ receptor agonists on cardiovascular disease (CVD) morbidity and mortality in the diabetic, is first, to seek to enhance both an awareness of, and greater familiarity among our own physicians, with this class of drug, and secondly, to effect a timely review of the recent literature as it relates to the tremendous possibilities for the potential clinical gains that might accrue from their use, in so far as this may serve to ameliorate the ravages of the CVD disease that all too tragically attends the type 2 diabetic, and more specifically those with the insulin resistance syndrome. (Mol Cell Biochem 263: 189-210, 2004).

Preventing cardiovascular disease in patients with diabetes: use of aspirin for primary prevention

Diabetics are at high risk for atherosclerotic cardiovascular disease (ASCVD) and are considered a coronary heart disease risk equivalent. The utility of aspirin in primary prevention of ASCVD in diabetic patients has been widely studied and is still debated. Overall, the current evidence suggests a modest benefit for reduction in ASCVD events with the greatest benefit among those with higher baseline risk, but at the cost of increased risk of gastrointestinal bleeding. Diabetic patients at higher risk (with 10-year ASCVD risk >10 %) are generally recommended for aspirin therapy if bleeding risk is felt to be low. A patient-provider discussion is recommended before prescribing aspirin therapy. Novel markers such as coronary artery calcium scores and high-sensitivity C-reactive protein may help refine ASCVD risk prediction and guide utility for aspirin therapy. This article will review the literature for the most up-to-date studies evaluating aspirin therapy for primary prevention of ASCVD in patients with diabetes.

Interrelated reduction of chemerin and plasminogen activator inhibitor-1 serum levels in rheumatoid arthritis after interleukin-6 receptor blockade

Inflammatory/metabolic factors and imbalance of haemostasis contribute to cardiovascular disease risk in rheumatoid arthritis (RA). Interleukin-6 (IL-6), a cytokine that plays an important role in immune responses, is implicated in its pathogenesis. In this study, the effects of the IL-6 receptor inhibitor, tocilizumab, on serum adipokines and coagulation/fibrinolysis factors in RA patients were examined. Nineteen consecutive patients (18 women, aged 48 ± 9 years) received six monthly infusions of 8 mg/kg tocilizumab for moderate or severe RA. Disease activity/severity, as well as serum levels of chemerin apelin, plasminogen activator inhibitor-1 (PAI-1), interleukin-6 (IL-6), glucose, insulin and lipids were measured at baseline and at 1, 3 and 6 months thereafter. Chemerin and PAI-1 levels decreased significantly from baseline through 3 to 6 months (from 256 ± 79 to 174 ± 12 and 210 ± 85 ng/ml; from 73 ± 27 to 56 ± 22 and 51 ± 28 pg/ml, respectively). Other adipokines did not change, despite increases in adiposity. In multivariate models, significant independent associations were found between baseline chemerin with age, body mass index, remission of disease, HAQ-Di, CRP and PAI-1. Chemerin decrease at 6 months was significantly associated with PAI-1 and IL-6 changes at 6 months. Baseline PAI-1 associated negatively with remission of disease and total cholesterol, while PAI-1 change at 6 months associated with chemerin changes and smoking status. In conclusion, inhibition of IL-6 signaling in RA favorably alters chemerin and PAI-1 levels in an interrelated manner, despite increasing adiposity. This might represent a dual anti-inflammatory and anti-thrombotic/fibrinolytic mechanism of tocilizumab that may reduce cardiovascular event risk in RA patients.

Evaluation of risk markers fluctuation during an initial therapy with rosiglitazon in patients suffering from metabolic syndrome

The aim of this study was to examine the effects of hypoglycaemic drug-agonists of PPAR-gama receptors-rosiglitazone (Avandia,4 mg - Glaxo Smith Kline) on values of wide-spread risk - markers-fibrinogen, C-reactive protein and uric acid and glicolysated haemoglobin HbA1C as parameter of metabolic control .We included fourty patients with criteria for metabolic syndrome and evaluated results into groups of diabetic and prediabetic patients according to criteria of IDF (International Diabetic Federation)These risk markers and glicolysated haemoglobin HbA1C were observed at the start of therapy, then after four, eight and twelve weeks and results were compared and statistically calculated. Three months initial therapy with rosiglitazone significantly reduced values of HbA1C, fibrinogen and CRP but not uric acid in prediabetic patients.Rosiglitazone initial three months therapy significantly reduced HbA1C, fibrinogen and uric acid, but not CRP in diabetic patients.

Fibrinolytic dysfunction after gestation is associated to components of insulin resistance and early type 2 diabetes in latino women with previous gestational diabetes

Among patients with metabolic syndrome (MS), atherosclerosis and abnormal fibrinolytic function are frequently present, mostly owing to an increase in plasminogen activator inhibitor-1(PAI-1). We analyze PAI-1 in pregnant women, both normal and with gestational diabetes (GDM) and postpartum regarding its correlation to MS surrogates. Clinical characteristics, glucose tolerance (100g-OGTT), lipids, PAI-1 antigen, insulin sensitivity (HOMA-S), and pancreatic beta-cell function (HOMA-B) were investigated in 34 women. Eleven had normal glucose tolerance (NGT) during pregnancy and 23 had GDM (all GAD antibodies-negative). All patients were studied at 28-34 weeks of gestation and 16-24 weeks after delivery (75 g-OGTT). Parameters of interest were determined using commercial test systems. During pregnancy, PAI-1 was not statistically different between NGT and GDM (47+/-25 ng/ml versus 47+/-28 ng/ml, p=0.9). After gestation, 19 (56%) women had NGT (11 of them from previous NGT group) and 15 (44%) had impaired glucose tolerance (IGT) or DM. The IGT (IGT+DM) group had higher PAI-1 (p=0.01), which did not decreased after delivery NGT-NGT before and after delivery (47+/-25 ng/ml versus 6+/-5 ng/ml; p<0.001), GDM-NGT (62+/-36 ng/ml versus 14+/-15 ng/ml; p=0.001) and GDM-IGT (39+/-20 ng/ml versus 27+/-23 ng/ml; p=0.15). PAI-1 levels were positively correlated (p<0.05) to total cholesterol (r(s)=0.37), triglycerides (r(s)=0.48), fasting plasma glucose (r(s)=0.52), 2-h plasma glucose in the OGTT (r(s)=0.58) and were negatively correlated (p<0.05) with HOMA-S (r(s)=-0.42) and HOMA-B (r(s)=-0.38). Fibrinolytic dysfunction is still present in GDM women and is associated with early development of IGT or T2DM. PAI correlated with surrogate markers of MS levels and may identify a group of women at risk for macroangiopathy.

Weight management for type 2 diabetes mellitus: global cardiovascular risk reduction

Most patients with type 2 diabetes mellitus are overweight or obese, and the relation between obesity, especially of the visceral compartment, and the risk for developing diabetes is well recognized. Excessive adipose tissue is associated with insulin resistance as well as the increased expression of proinflammatory cytokines and prothrombotic factors, all of which contribute to elevating the risk for coronary artery disease (CAD). In particular, abdominal obesity, or excess visceral adiposity, has been linked to a cluster of risk factors (high blood pressure, hypertriglyceridemia, low levels of high-density lipoprotein cholesterol, and impaired fasting glucose) that constitute the metabolic syndrome, the presence of which confers an increased risk for type 2 diabetes and cardiovascular disease. In fact, a large waist circumference, a surrogate measure of abdominal adiposity, is 1 of the main criteria for diagnosing the metabolic syndrome. Lifestyle modification is the first-line approach to the management of obesity and the metabolic syndrome. However, if patients are unable to achieve a weight loss of 5%-10% of initial body weight and improve cardiometabolic risk factors with lifestyle modification alone, physicians should consider using adjunctive long-term pharmacotherapy. A variety of approved and investigational pharmacologic agents, including sibutramine, orlistat, metformin, and rimonabant, have been shown to reduce weight and ameliorate metabolic syndrome components, thereby reducing cardiovascular risk. Such global risk reduction is crucial for patients with diabetes, in whom CAD is a major cause of mortality.

Insulin resistance, diabetes and cardiovascular risk: approaches to treatment

The prevalence of diabetes is increasing worldwide. Insulin resistance and diabetes mellitus are major predictors of cardiovascular ischaemic disease. Other risk factors for cardiovascular death including hypertension, dyslipidaemia, smoking and visceral obesity are especially lethal in diabetics. C-reactive protein, plasminogen activator inhibitor-1, matrix metalloproteinases and other emerging risk factors and their roles are continually being researched and discovered. Treatment of this syndrome must be aimed at lifestyle modification, glycaemic control and management of concomitant risk factors. Diet and exercise play a vital role in the treatment of diabetes and the metabolic syndrome. Weight reduction and increased physical activity will improve insulin resistance, hyperglycaemia, hypertension and dyslipidaemia. Hypertension management has been shown to be especially important in diabetics to prevent cardiovascular events. Likewise, multiple clinical trials show that reduction of cholesterol is even more vital in diabetics than the general population for risk reduction of coronary disease. There is a great deal of evidence that tight control of glycaemia is essential to treatment of this condition. There are a variety of available pharmacological agents available including metformin, insulin secretagogues, alpha-glucosidase inhibitors, thiazolidinediones and insulin. The mechanisms and side effects of these medications are discussed. As macrovascular disease is the major cause of morbidity and mortality, an early, aggressive, multi-factorial approach to treatment of the metabolic syndrome and diabetes is vital to prevent adverse cardiac outcomes.

Antiplatelet agents for the prevention of cardiovascular disease in diabetes mellitus

Patients with diabetes mellitus (DM) have accelerated atherothrombotic disease of coronary, cerebral, leg, and other vessels. The major cause of death is cardiovascular, and the risk for a myocardial infarction (MI) in a patient with DM who has never had a MI is the same as a nondiabetic individual who has already had one. In this paper, we review the major reasons for a prothrombotic state in patients with DM: alterations in the intrinsic coagulation and fibrinolytic systems and many abnormalities of platelet function. Increased platelet thromboxane production as well as activation of platelet receptors for fibrinogen and or adenosine diphosphate (ADP) are often present, and can be treated with aspirin (acetylsalicylic acid) and/or receptor blockers. Review of the major primary prevention trials in DM indicates that a significantly reduced risk for MI or major cardiovascular events may be obtained by enteric-coated aspirin, 81-325 mg/day. There is emerging consensus that this is recommended strategy in adult (aged >30 years) patients with DM who are at high vascular risk. Surveys suggest that this includes virtually every patient with type 2 DM in the US, as well as many patients with complicated type 1 DM. These recommendations are also appropriate for secondary prevention. Data supporting the use of clopidogrel as an alternative drug in the case of aspirin allergy or other contraindications are reviewed. Evidence is presented in support of using aspirin plus clopidogrel in acute coronary syndromes (ACS), and a meta-analysis of six trials of platelet glycoprotein (GP) IIb/IIIa inhibitors and aspirin in diabetic patients with ACS establishes this regimen as an effective choice. Although bleeding episodes are more common with combined antiplatelet therapy for ACS than for aspirin alone, the benefit of a significant reduction in 30-day mortality appears to outweigh the risk of major bleeding. It is concluded that major advances in our understanding of the prothrombotic state in DM have been made. Evidence from controlled clinical trials supports the use of enteric-coated aspirin, 81-325 mg/day, as a primary and a secondary prevention strategy in adults with DM with high vascular risk. In ACS, combination therapy with aspirin plus clopidogrel or alternatively, aspirin plus a platelet GP IIb/IIIa inhibitor is supported by prospective trial data. These approaches should be added to the other multifactorial preventive strategies directed at lowering the risk for major vascular events in patients with DM.

The effect of 17 beta-oestradiol on variables of coagulation and fibrinolysis in postmenopausal women with type 2 diabetes mellitus

Type 2 diabetes mellitus is frequently accompanied by hypercoagulability and hypofibrinolysis. Both are related to increased cardiovascular risk, but possibly with endothelial injury as well. Studies with nondiabetic persons indicate that unopposed oestrogen replacement therapy (oERT) decreases cardiovascular risk, possibly mediated in part by effects on coagulation and fibrinolysis. In a double-blind, randomised placebo-controlled trial, we assessed the effect of oral 17 beta-oestradiol daily during 6 weeks on indicators of coagulation and of fibrinolysis in postmenopausal women with type 2 diabetes mellitus. We observed significant increases of Factor VII (FVII) and von Willebrand factor (vWF) after oERT and no change in the already high fibrinogen. Prothrombin fragment 1 + 2 (F1 + 2) increased after oERT, whereas thrombin-antithrombin (TAT) complexes was unchanged, but increments of F1 + 2 and TAT correlated. Soluble fibrin (SF) levels remained stable. In fibrinolysis, a clear reduction in plasminogen activator inhibitor 1 (PAI-1) was observed, but no significant change in tissue-type plasminogen activator antigen (t-PA-Ag) or activity was found, although fibrinolytic activity assessed as t-PA activity (t-PA-Act) tended to increase after oERT. Indicators of fibrinolytic activity (plasmin-antiplasmin complexes and fibrin degradation products) however did not change. oERT increased C-reactive protein (CRP) but none of the coagulation or fibrinolysis changes significantly associated with the CRP changes. It is concluded that oERT increases the coagulation potency as well as the fibrinolytic potency raising the question of the net effect in their balance. Increase in F1 + 2 suggests that in diabetic women oERT effectively increases the chronic, continuous activation of coagulation, which appears to be compensated for or not effective in the blood compartment as judged from the unchanged levels of SF. Suspected increased fibrin formation in the vascular wall is at least not followed by increases in fibrinogen degradation products (TDP), which suggests the possibility of accumulation and increased cardiovascular risk. The results indicate that specific attention should be paid to fibrin turnover in studying other categories of women and the effects of the addition of progesterone.

Effect of glucose tolerance status on PAI-1 plasma levels in overweight and obese subjects

OBJECTIVE

The aim of our study was to examine whether plasminogen activator inhibitor-1 (PAI-1) plasma levels varied as a function of differences in glucose tolerance status independently of body fatness, body-fat distribution, and insulin sensitivity.

RESEARCH METHODS AND PROCEDURES

Plasma PAI-1 antigen levels, along with insulin resistance [measured by homeostatic model assessment (HOMA(IR))], central fat accumulation, body composition, blood pressure, and fasting concentrations of glucose, insulin, and lipids, were measured in 229 overweight and obese [body mass index (BMI) > or =25 kg/m(2)) subjects with normal glucose tolerance (NGT) and in 44 age- and BMI-matched subjects with impaired glucose tolerance (IGT).

RESULTS

Plasma PAI-1 antigen levels were significantly higher in IGT than in NGT subjects. Log PAI-1 was positively correlated with BMI, HOMA(IR), and log insulin, and inversely associated with high-density lipoprotein-cholesterol both in IGT and in NGT individuals. On the other hand, log PAI-1 was positively correlated with waist circumference, fat mass (FM), fat-free mass, systolic and diastolic blood pressure, and log triglycerides only in the NGT group. After multivariate analyses, the strongest determinants of PAI-1 levels were BMI, FM, waist circumference, and high-density lipoprotein cholesterol in the NGT group and only HOMA(IR) in the IGT cohort.

DISCUSSION

This study demonstrates that PAI-1 concentrations are higher in IGT than in NGT subjects. Furthermore, we suggest that the influences of total adiposity, central fat, and insulin resistance, main determinants of PAI-1 concentrations, are different according to the degree of glucose tolerance.

Regulation of plasminogen activator inhibitor-1 secretion by urokinase and tissue plasminogen activator in rat epithelioid-type smooth muscle cells

Tissue plasminogen activator (tPA) and urokinase (uPA) are targets of plasminogen activator inhibitor-1 (PAI-1) inhibition. We have previously shown that both proteases can also induce PAI-1 secretion in rat smooth muscle cells (SMCs). We now report that both proteases appear to use very similar cellular mechanisms for signal transduction. They induced PAI-1 secretion using a pathway(s) involving protein kinase C (PKC). They also activated the Raf/Mek/mitogen-activated protein kinase (MAPK) pathway, which lies downstream of PKC activation. Activation of protein kinase A (PKA), however, lowered PAI-1 secretion induced by uPA and tPA, as a result of an inhibition of the PKC pathway and inhibition of Raf, Mek and MAPK phosphorylations. Src and syk family non-receptor tyrosine kinases (TK) were also involved in PAI-1 induction. The mechanisms of interaction of these tyrosine kinases with other pathways appeared to be quite different: src appeared to act within the PKC and PKA pathways, while syk operated independently of these pathways. Furthermore, whereas src inhibition resulted in inhibition of Raf/Mek/Erk phosphorylations, syk inhibition could only inhibit Mek and Erk phosphorylations but not the phosphorylation of Raf. These multiple pathways utilized by uPA and tPA to modulate PAI-1 secretion might be involved in determining the proteolytic or antiproteolytic potential of the SMCs under different pathophysiological conditions.

Insulin resistance is associated with increased circulating level of thrombin-activatable fibrinolysis inhibitor in type 2 diabetic patients

Hypofibrinolysis is a common finding in patients with diabetes mellitus (DM) and obesity and a risk factor for the development of cardiovascular disease. Recently, a new potent inhibitor of fibrinolysis, the thrombin-activatable fibrinolysis inhibitor (TAFI) has been isolated and characterized from human plasma. The present study was undertaken to assess the activity and circulating level of TAFI and its relation to fibrinolytic function and obesity in patients with type 2 DM. Fifty-seven patients with type 2 DM (38 men, 19 women) were enrolled in this study. DM patients were categorized in age-matched obese [body mass index (BMI) > or = 25] and nonobese (BMI < 25) groups. The plasma concentration and activity of TAFI were significantly (P < 0.05) higher in DM patients than in healthy controls. The plasma levels and activity of TAFI were significantly (P < 0.05) elevated in obese DM patients compared with nonobese DM and nonobese healthy subjects. RT-PCR demonstrated the expression of TAFI in human adipose tissue and in human endothelial cells. The plasma levels of TAFI were independently and significantly correlated with glucose intolerance (HbA(1c)), with obesity (BMI, visceral fat area), and with an indicator of insulin resistance (glucose infusion rate). This study showed that increased circulating level of TAFI may be an important causative factor of hypofibrinolysis in patients with type 2 diabetes, obesity and insulin resistance.

Post-exercise alcohol ingestion perturbs blood haemostasis during recovery

It is known that exercise induces modification in blood haemostasis. It is, however, not known whether alcohol consumption post-exercise influences these modifications during recovery. Eleven moderately active young men were studied immediately after a standardised cycle ergometer test and during the 24-hour period of recovery. Alcohol (0. 7 g/kg body mass) was given 1 hour after exercise on one test occasion, while an equal volume of alcohol-free solution was administered on the other. Exercise induced a significant increase in factor VIII activity with a significant shortening of activated partial thromboplastin time. Parallel increases in tissue plasminogen activity and antigen with a concomitant decrease in tissue plasminogen activator inhibitor-1 activity were also observed after exercise. During recovery, while the increase in factor VIII activity post-exercise persisted in both trials, fibrinolytic activity demonstrated a sharp fall. The elevated factor VIII activity was significantly higher at 5 and 22 hours during the alcohol trial compared with the control. Although no demonstrable effect of alcohol on tissue plasminogen activator activity was present from 1 hour after ingestion onward, tissue plasminogen activator antigen and tissue plasminogen activator inhibitor-1 antigen increased significantly 22 hours following alcohol ingestion. Further comparison between trials revealed a higher plasminogen activator inhibitor-1 activity 5 hours after alcohol ingestion. In conclusion, exercise-induced changes to blood haemostasis are balanced during exercise but not during recovery. Alcohol consumption after physical exercise further perturbs blood haemostasis and could constitute a thrombotic risk.

Plasminogen activator inhibitor-1 and apolipoprotein E gene polymorphisms and diabetic angiopathy

BACKGROUND

A point mutation in the plasminogen activator inhibitor-1 (PAI-1) gene and a three-allelic variation in the apolipoprotein-E (ApoE) gene have been suggested as risk factors for the development of diabetic micro- and macrovascular complications.

METHODS

We studied 198 type 1 diabetic patients with diabetic nephropathy [121 men, age (mean+/-SD) 41+/-10 years, diabetes duration 28+/-8 years] and 192 patients with persistent normoalbuminuria (118 men, age 43+/-10 years, diabetes duration 27+/-9 years).

RESULTS

Male patients with nephropathy had elevated plasma PAI-1 levels [geometric mean (95% CI)], 70 (62-79) ng/ml, compared with normoalbuminuric men, 43 (38-47) ng/ml, P<0.001. Even though nephropathic patients with the 4G4G genotype tended to have higher plasma PAI-1 levels, P=0.06, no difference in allele frequency (4G/5G) was seen between patients with and without nephropathy: 0.538/0.462 vs 0.539/0.461, respectively. Nor did ApoE allele frequencies (epsilon2/epsilon3/epsilon4) differ between nephropathic and normoalbuminuric patients: 0.099/0.749/0. 152 vs 0.081/0.745/0.174, respectively. Genotype distributions were also similar, n.s. Coronary heart disease was more prevalent (36%) among nephropathic patients carrying the atherogenic epsilon4-allele compared with 12% in patients with the epsilon3,epsilon3 genotype, P<0.001. No associations between diabetic retinopathy and PAI-1 or ApoE polymorphisms were observed, n.s.

CONCLUSIONS

The ApoE polymorphism may accelerate the development of coronary heart disease often seen in Caucasian patients with type 1 diabetes and diabetic nephropathy, a condition characterized by elevated plasma PAI-1 in men. Neither the PAI-1 nor the ApoE gene polymorphism contributes to the genetic susceptibility to diabetic nephropathy or retinopathy.

ACE, PAI-1, decorin and Werner helicase genes are not associated with the development of renal disease in European patients with type 1 diabetes

BACKGROUND

Genetic factors are involved in the development of diabetic nephropathy in Type 1 diabetes. We have examined the association of four candidate genes, angiotensin converting enzyme (ACE): insertion/deletion (I/D) polymorphism, plasminogen activator inhibitor-1 (PAI-1): 4G/5G polymorphism, decorin: 179/183/185 polymorphism and Werner syndrome helicase: C/R polymorphism, with the presence of diabetic nephropathy in Type 1 diabetic patients.

METHODS

175 Type 1 diabetic patients with albuminuria (59 with microalbuminuria and 116 with macroalbuminuria) were compared with 136 Type 1 diabetic patients with normoalbuminuria and duration of disease longer than 15 years (mean+/-SD: 25+/-8 years). 200 non-diabetic subjects were also studied as background population.

RESULTS

We found no association in the polymorphism of the four genes examined between patients with and without diabetic nephropathy and the control subjects.

CONCLUSIONS

The genes studied are unlikely to be involved in the susceptibility to nephropathy in Type 1 diabetic patients.

[Heart pathology of extracardiac origin. XI. Cardiac repercussions of diabetes mellitus]

Diabetes mellitus is one of the diseases with the greatest risk of developing coronary disease (CD), with the estimation of this risk in relation to the general population being from 2 to 4-fold greater. The existence of diabetes worsens the prognosis of CD and thus, postinfarction mortality in these patients is double that observed in non-diabetic patients. Together with the risk factors found in the general population, those of special interest are those derived from diabetes itself, such as hyperglycemia, dyslipemia, coagulation disorders and hyperinsulinemia or insulin resistance. Among these, the most important is probably the hyperglycemia which may contribute to the appearance of CD by different mechanisms such as proteic glycosylation, accumulation of sorbitol, increase in the synthesis of protein kinase C or oxidative stress. It must not be forgotten that an old controversy has recently been brought up suggesting that sulphonylureas may have a certain cardiotoxic effect, probably acting on the potassium channels dependent on ATP. Acute myocardial infarction in diabetic patients carries a greater risk of congestive heart failure, recurrent infarction, arrhythmia and cardiogenic shock, with one of its characteristics being the possibility of being silent when autonomic neuropathy is present. The prognosis of CD may be markedly improved by obtaining optimum glycemic control during the hours following infarction using intensified treatment. Diabetic myocardiopathy as a differentiated nosology responsible for alterations in myocardial contractile function and greater prevalence of heart failure in these patients seems to be clearly demonstrated although its etiology remains unknown.

Effects of heparin treatment on hemostatic abnormalities in obese non-insulin-dependent diabetic patients

This study was conducted to identify the mechanisms responsible for coagulative and fibrinolytic alterations and to study the effects of a short-term treatment with low-dose heparin on hemostatic abnormalities in obese non-insulin-dependent diabetes mellitus (NIDDM) patients. Four groups of age- and sex-matched patients were studied: (1) lean nondiabetic subjects (n = 30) with a body mass index (BMI) less than 25 kg/m2 (lean control subjects), (2) obese nondiabetic subjects (n = 30) with a BMI greater than 30 kg/m2 (obese control subjects), (3) lean NIDDM patients (n = 30), and (4) obese NIDDM patients (n = 30). All subjects were tested on the following parameters: fibrinogen, factor VII, prothrombin fragment 1 + 2 (F1 + 2), thrombin-antithrombin III complexes (TAT), tissue plasminogen activator (t-PA) antigen (Ag) before and after venous occlusion (VO), and plasminogen activator inhibitor type-1 (PAI-1) activity pre- and post-VO. In addition, all these parameters were evaluated in obese NIDDM patients after 10 days of treatment with a single dose of 12,500-U/d subcutaneous calcium heparin and after a 10-day washout period. At baseline, obese nondiabetic subjects, lean NIDDM patients, and especially obese NIDDM patients displayed significantly (P < .01) higher levels of fibrinogen, factor VII, F1 + 2, TAT, t-PA(Ag) pre-VO, and PAI-1 pre- and post-VO and significantly (P < .01) lower levels of t-PA(Ag) post-VO. In obese NIDDM patients treated with heparin fibrinogen, factor VII, F1 + 2, TAT, t-PA(Ag) pre-VO, and PAI-1 pre- and post-VO levels significantly (P < .01) decreased and t-PA(Ag) post-VO levels significantly (P < .01) increased at the end of treatment. Our findings demonstrate in obese nondiabetic subjects, lean NIDDM patients, and especially obese NIDDM patients the hemostatic abnormalities contributing to an enhanced risk of thrombotic complications. We conclude that in obese NIDDM patients, short-term treatment with heparin may reduce this thrombophilic state and have a potential benefit in the progression of diabetic microvascular and macrovascular disease and needs further investigation.

Do tissue plasminogen activator-plasminogen activator inhibitor-1 complexes relate to the complications of insulin-dependent diabetes mellitus? Pittsburgh Epidemiology of Diabetes Complications Study

The purpose of this study was to examine the potential relationship of tissue plasminogen activator-plasminogen activator inhibitor-1 (tPA-PAI-1) complexes and diabetic complications in individuals with insulin-dependent diabetes mellitus (IDDM). To address this issue, data from the third follow-up visit of participants in the Epidemiology of Diabetes Complications (EDC) study were examined. There were 454 participants, aged 32 +/- 8 years, with duration of IDDM of 23 +/- 8 years. Higher levels of tPA-PAI-1 complexes were seen for both men and women with IDDM complications. Specifically, statistically significant differences were seen in men with neuropathy (1.81 +/- 0.9 versus 1.42 +/- 0.8 ng/mL, p < 0.01), microalbuminuria (1.77 +/- 1.1 versus 1.35 +/- 0.6 ng/mL, p < 0.01), retinopathy (1.67 +/- 0.9 versus 1.43 +/- 0.8 ng/mL, p < 0.05), and lower extremity arterial disease (1.93 +/- 0.7 versus 1.50 +/- 0.9 ng/mL, p < 0.05) versus men without the particular complication. In women, higher complex levels were shown for those with retinopathy (1.51 +/- 0.8 versus 1.29 +/- 1.1 ng/mL, p < 0.01). Potential mechanisms for the relationship of higher complex levels and diabetic complications include an altered fibrinolytic response and/or insulin resistance. Because the results are cross sectional, it cannot be established whether the higher concentration of complexes is a result of the presence of complications or are antecedent. Prospective follow-up will be required to determine if tPA-PAI-1 complexes are predictive of the development of IDDM complications.

Thrombogenic and fibrinolytic factors and cardiovascular risk in non-insulin-dependent diabetes mellitus

Disturbances of the haemostatic system may favour the development of vascular damage and the final occlusion events in the progress of coronary heart disease (CHD). It has been shown recently in epidemiological studies, that increased concentration of several factors, mainly fibrinogen, factor VII, von Willebrand factor (vWF), and the fibrinolytic variables plasminogen activator inhibitor 1 (PAI-1) and tissue plasminogen activator (t-PA), can be considered as risk factors for CHD. As morbidity and mortality through coronary atherosclerosis are higher in type 2 diabetic patients than in nondiabetic subjects and as insulin resistance represents a situation which favours the development of atherothrombosis, evaluation of the haemostatic factors which are recognized as risk factors may be interesting to consider in these situations. In fact, it has been shown that the fibrinolytic parameters PAI-1 and t-PA antigen are strongly related to the metabolic disorder of insulin resistance, whereas the link with fibrinogen, factor VII, and vWF remains weak. Many cross-sectional studies conducted in different populations have shown that PAI-1 and t-PA antigen (which represents t-PA/PAI-1 complexes) are strongly correlated with insulin, triglyceride, high-density lipoprotein (HDL) cholesterol, body mass index, walst-to-hip ratio and blood pressure, and that the improvement of insulin resistance improves in parallel the metabolic abnormalities and the concentration of the fibrinolytic parameters. Attempts at explaining the elevated PAI-1 and t-PA antigen levels in the insulin resistance syndrome have involved many clinical and in vitro studies, in which the role of insulin, insulin propeptides, very-low-density lipoprotein (VLDL) triglyceride, insulin resistance per se, glucose, and adipose tissue have successively been analysed and the main results of these studies are presented in this review. Due to recent experimental data from animal models of thrombosis, a pathogenic role of decreased fibrinolytic activity or increased PAI-1 levels can be proposed and could play a role in the development of vascular disease in subjects with Type 2 diabetes or insulin resistance.

Heart disease in diabetes mellitus

The spectrum of heart disease in diabetic patients is broad and complex. This article discusses the epidemiologic associations between the two causes. It attempts to summarize the effects of diabetes at the cellular, vascular, and myocardial levels. The clinical manifestations are explored, and the treatment of heart disease as it pertains to diabetic patients is discussed.

Randomized trial of insulin-glucose infusion followed by subcutaneous insulin treatment in diabetic patients with acute myocardial infarction (DIGAMI study): effects on mortality at 1 year

OBJECTIVES

We tested how insulin-glucose infusion followed by multidose insulin treatment in diabetic patients with acute myocardial infarction affected mortality during the subsequent 12 months of follow-up.

BACKGROUND

Despite significant improvements in acute coronary care, diabetic patients with acute myocardial infarction still have a high mortality rate.

METHODS

A total of 620 patients were studied: 306 randomized to treatment with insulin-glucose infusion followed by multidose subcutaneous insulin for > or = 3 months and 314 to conventional therapy.

RESULTS

The two groups were well matched for baseline characteristics. Blood glucose decreased from 15.4 +/- 4.1 to 9.6 +/- 3.3 mmol/liter (mean +/- SD) in the infusion group during the 1st 24 h, and from 15.7 +/- 4.2 to 11.7 +/- 4.1 among control patients (p < 0.0001). After 1 year 57 subjects (18.6%) in the infusion group and 82 (26.1%) in the control group had died (relative mortality reduction 29%, p = 0.027). The mortality reduction was particularly evident in patients who had a low cardiovascular risk profile and no previous insulin treatment (3-month mortality rate 6.5% in the infusion group vs. 13.5% in the control group [relative reduction 52%, p = 0.046]; 1-year mortality rate 8.6% in the infusion group vs. 18.0% in the control group [relative reduction 52%, p = 0.020]).

CONCLUSIONS

Insulin-glucose infusion followed by a multidose insulin regimen improved long-term prognosis in diabetic patients with acute myocardial infarction.

Effects of captopril therapy on endogenous fibrinolysis in men with recent, uncomplicated myocardial infarction

OBJECTIVES

This study investigated the effects of captopril therapy on endogenous fibrinolysis in men with recent, uncomplicated myocardial infarction.

BACKGROUND

Angiotensin-converting enzyme inhibitors reduce the incidence of acute coronary syndromes in patients with mild left ventricular dysfunction after myocardial infarction. Abnormal endogenous fibrinolysis, reflected in increased levels of endogenous tissue-type plasminogen activator (t-PA) antigen and plasminogen activator inhibitor type 1 activity, is associated with an increased risk of myocardial infarction in patients with ischemic heart disease.

METHODS

In a randomized, double-blind crossover study beginning 8 weeks after uncomplicated myocardial infarction, patients received 4 weeks of placebo and 4 weeks of captopril (75 mg daily) therapy. At the end of each treatment period, we measured t-PA antigen and plasminogen activator inhibitor type 1 antigen and activity.

RESULTS

Median values in the 15 patients after placebo and in 12 normal men matched for age and body mass index were, respectively, t-PA antigen 16.0 versus 9.5 ng/ml (p = 0.001), plasminogen activator inhibitor type 1 antigen 17.3 versus 8.6 ng/ml (p = 0.29) and plasminogen activator inhibitor type 1 activity 13.2 versus 6.3 AU/ml (p = 0.04). After 4 weeks of treatment with captopril in the 15 patients, the estimated (95% confidence interval) median reduction in t-PA antigen was 7.3 ng/ml (-4.6 to -10.3 ng/ml, p = 0.001), in plasminogen activator inhibitor type 1 antigen 3.1 ng/ml (+1.5 to -8.4 ng/ml, p = 0.17) and in plasminogen activator inhibitor type 1 activity -2.2 AU/ml (-1.0 to -4.3 AU/ml, p = 0.02).

CONCLUSIONS

Treatment with captopril after uncomplicated myocardial infarction is associated with a significant decrease in elevated levels of t-PA antigen and plasminogen activator inhibitor type 1 activity. This may help to explain the reduction in risk of coronary thrombosis associated with the use of angiotensin-converting enzyme inhibitors.