Antigens of Tissue Plasminogen Activator and Plasminogen Activator Inhibitor 1: Correlates in Nonsmoking Japanese and Caucasian Men and Women

Urokinase-type plasminogen activator and plasminogen activator inhibitor-1 complex as a serum biomarker for COVID-19

Patients with coronavirus disease-2019 (COVID-19) have an increased risk of thrombosis and acute respiratory distress syndrome (ARDS). Thrombosis is often attributed to increases in plasminogen activator inhibitor-1 (PAI-1) and a shut-down of fibrinolysis (blood clot dissolution). Decreased urokinase-type plasminogen activator (uPA), a protease necessary for cell-associated plasmin generation, and increased tissue-type plasminogen activator (tPA) and PAI-1 levels have been reported in COVID-19 patients. Because these factors can occur in free and complexed forms with differences in their biological functions, we examined the predictive impact of uPA, tPA, and PAI-1 in their free forms and complexes as a biomarker for COVID-19 severity and the development of ARDS. In this retrospective study of 69 Japanese adults hospitalized with COVID-19 and 20 healthy donors, we found elevated free, non-complexed PAI-1 antigen, low circulating uPA, and uPA/PAI-1 but not tPA/PAI-1 complex levels to be associated with COVID-19 severity and ARDS development. This biomarker profile was typical for patients in the complicated phase. Lack of PAI-1 activity in circulation despite free, non-complexed PAI-1 protein and plasmin/α2anti-plasmin complex correlated with suPAR and sVCAM levels, markers indicating endothelial dysfunction. Furthermore, uPA/PAI-1 complex levels positively correlated with TNFα, a cytokine reported to trigger inflammatory cell death and tissue damage. Those levels also positively correlated with lymphopenia and the pro-inflammatory factors interleukin1β (IL1β), IL6, and C-reactive protein, markers associated with the anti-viral inflammatory response. These findings argue for using uPA and uPA/PAI-1 as novel biomarkers to detect patients at risk of developing severe COVID-19, including ARDS.

Low-dose rt-PA may not decrease the incidence of symptomatic intracranial haemorrhage in patients with high risk of symptomatic intracranial haemorrhage

BACKGROUND

Recombinant tissue plasminogen activator (rt-PA) has been used as the standard treatment for acute ischemic stroke (AIS). The following study investigates whether low-dose rt-PA can decrease the incidence of symptomatic intracranial haemorrhage (sICH) in AIS patients with high-risk sICH compared to standard-dose rt-PA.

MATERIALS AND METHODS

Data from the Thrombolysis Implementation and Monitor of Acute Ischemic Stroke in China (TIMS-China) studies were assessed to explore risk factors for sICH after intravenous thrombolysis. For high-risk sICH patients (age ≧70 years old, or with diabetes, or serum glucose on admission >9.0 mmol/L, or NIHSS on admission>20, or with cardioembolism), standard-dose rt-PA (0.85 to 0.95 mg/kg) and low- dose rt-PA (0.5 to 0.7 mg/kg) were compared. Primary outcome measure was the incidence of sICH, and the secondary outcome measures were 7-day mortality and 90-day functional independence outcome (modified Rankin scale, 0-2).

RESULTS

A total of 554 patients were enrolled (60 cases for low dose, and 494 cases for standard dose). Median rt-PA doses were 0.63 and 0.90 mg, respectively. After adjustment for the baseline variables, low-dose rt-PA did not decrease the incidence of sICH (per SITS-MOST criteria, 3.33% versus 2.23%, P = 0.3467) compared to low dose. The low-dose group revealed less functional independence outcomes (modified Rankin scale, 0-2) compared to standard-dose group (36.67% versus 52.43%; odds ratio = 0.49; p = 0.0204) at 90 days.

CONCLUSIONS

Our study suggests that low-dose intravenous rt-PA for high-risk sICH stroke in Chinese patients may not decrease the incidence of sICH, and concomitant with a poor outcome compared to standard-dose rt-PA.

ABBREVIATIONS

rt-PA: recombinant tissue plasminogen activator; AIS: acute ischemic stroke; sICH: symptomatic intracranial haemorrhage.

The Circulatory Risk in Communities Study (CIRCS): A Long-Term Epidemiological Study for Lifestyle-Related Disease Among Japanese Men and Women Living in Communities

The Circulatory Risk in Communities Study (CIRCS) is an ongoing community-based epidemiological study of lifestyle-related disease involving dynamic prospective cohorts of approximately 12,000 adults from five communities of Japan: Ikawa, Ishizawa and Kita-Utetsu (Akita Prefecture), Minami-Takayasu (Osaka Prefecture), Noichi (Kochi Prefecture), and Kyowa (Ibaraki Prefecture). One of the most notable features of CIRCS is that it is not only an observational cohort study to identify risk factors for cardiovascular diseases (CVD), such as stroke, coronary heart disease, and sudden cardiac death, but it also involves prevention programs for CVD. Using basic, clinical, epidemiological, and statistical techniques, CIRCS has clarified characteristics of CVD and the related risk factors to develop specific methodologies towards CVD prevention in Japanese middle-aged or older adults for more than half a century.

Low- versus Standard-Dose Intravenous Tissue-Type Plasminogen Activator for Acute Ischemic Stroke: An Updated Meta-Analysis

BACKGROUND

We performed a meta-analysis to compare the efficacy and safety between low- and standard-dose intravenous (IV) tissue-type plasminogen activator (tPA) for acute ischemic stroke (AIS) patients within 4.5 hours of symptom onset.

METHODS

We searched PubMed and EMBASE for relevant studies from inception to June1, 2017. Cohort or randomized controlled studies for AIS within 4.5 hours of symptom onset with comparison between low-dose and standard-dose tPA were included. The primary efficacy end point was favorable functional outcome (modified Rankin scale scores [mRS] of 0-1) at 90 days. The primary safety end point was the incidence rate of symptomatic intracerebral hemorrhage (sICH). The secondary end points were independent functional outcome (mRS scores of 0-2) and mortality.

RESULTS

A total of 11 studies were pooled in this meta-analysis. The low-dose strategy appeared to be as effective as standard-dose tPA (43.4% versus 45.4%; odds ratio [OR] = 0.93, 95% confidence interval [CI]: 0.78-1.10; P = .38) in primary efficacy outcome. The secondary efficacy outcome produced similar results (57.3% versus 57.0%; OR = 0.95, 95% CI: 0.86-1.05; P= .33). There was no evidence of statistical difference for sICH (4.2% versus 4.9%; OR = 1.02 [0.66-1.55]; P = .94) and mortality (9.0% versus 10.6%; OR = 0.99 [0.74-1.31]; P = .92) at 90 days between low- and standard-dose therapy. In a subgroup analysis by ethnicity, there was no significant difference between patients of Asian and non-Asian descent for any of the end points.

CONCLUSIONS

This study showed that AIS patients receiving low-dose IV-tPA had comparably efficacy and safety to those receiving standard-dose IV-tPA. However, the effect is especially pronounced within the Asian population, which limits the generalizability of these results.

Genetics of Plasminogen Activator Inhibitor-1 (PAI-1) in a Ghanaian Population

Plasminogen activator inhibitor 1 (PAI-1), a major modulator of the fibrinolytic system, is an important factor in cardiovascular disease (CVD) susceptibility and severity. PAI-1 is highly heritable, but the few genes associated with it explain only a small portion of its variation. Studies of PAI-1 typically employ linear regression to estimate the effects of genetic variants on PAI-1 levels, but PAI-1 is not normally distributed, even after transformation. Therefore, alternative statistical methods may provide greater power to identify important genetic variants. Additionally, most genetic studies of PAI-1 have been performed on populations of European descent, limiting the generalizability of their results. We analyzed >30,000 variants for association with PAI-1 in a Ghanaian population, using median regression, a non-parametric alternative to linear regression. Three variants associated with median PAI-1, the most significant of which was in the gene arylsulfatase B (ARSB) (p = 1.09 x 10⁻⁷). We also analyzed the upper quartile of PAI-1, the most clinically relevant part of the distribution, and found 19 SNPs significantly associated in this quartile. Of note an association was found in period circadian clock 3 (PER3). Our results reveal novel associations with median and elevated PAI-1 in an understudied population. The lack of overlap between the two analyses indicates that the genetic effects on PAI-1 are not uniform across its distribution. They also provide evidence of the generalizability of the circadian pathway’s effect on PAI-1, as a recent meta-analysis performed in Caucasian populations identified another circadian clock gene (ARNTL).

Rationale, Design, and Progress of the ENhanced Control of Hypertension ANd Thrombolysis Stroke Study (ENCHANTED) Trial: An International Multicenter 2 × 2 Quasi-Factorial Randomized Controlled Trial of Low- vs. Standard-Dose rt-PA and Early Intensive vs. Guideline-Recommended Blood Pressure Lowering in Patients with Acute Ischaemic Stroke Eligible for Thrombolysis Treatment

Rationale

Controversy exists over the optimal dose of intravenous (iv) recombinant tissue plasminogen activator (rt-PA) and degree of blood pressure (BP) control in acute ischaemic stroke (AIS). Asian studies suggest low-dose (0·6 mg/kg) is more efficacious than standard-dose (0·9 mg/kg) iv rt-PA, and guidelines recommend reducing systolic BP to <185 mmHg before and <180 mmHg after use of iv rt-PA, despite observational studies indicating better outcomes at much lower (<140 mmHg) systolic BP levels in this patient group.

Aims

The study aims to assess in thrombolysis-eligible AIS patients whether: (i) low-dose (0·6 mg/kg body weight; maximum 60 mg) iv rt-PA has non-inferior efficacy and lower risk of symptomatic intracerebral haemorrhage (sICH) compared to standard-dose (0·9 mg/kg body weight; maximum 90 mg) iv rt-PA; and (ii) early intensive BP lowering (systolic target 130–140 mmHg) has superior efficacy and lower risk of any ICH compared to guideline-recommended BP control (systolic target < 180 mmHg).

Design

The ENhanced Control of Hypertension And Thrombolysis strokE stuDy (ENCHANTED) trial is an independent, 2 × 2 quasi-factorial, active-comparison, prospective, randomized, open blinded endpoint (PROBE), clinical trial that is evaluating Arm [A] ‘rt-PA dose’ and/or Arm [B] ‘BP control’, using central Internet randomization and data collection in patients fulfilling local criteria for thrombolysis and clinician uncertainty over the study treatments. The treatment arms will be analyzed separately.

Study outcomes

The primary study outcome in both trial Arms is death or disability according to the modified Rankin scale (mRS, scores 2–6) assessed at 90 days. Secondary outcomes include sICH, any ICH, a shift (‘improvement’) in function across mRS scores, separately on death and disability, early neurological deterioration, recurrent major vascular events, health-related quality of life, length of hospital stay, need for permanent residential care, and health care costs.

Results

Following launch of the trial in February 2012, the study has recruited more than 2500 patients across a global network of approximately 100 sites in 15 countries. The required sample sizes are 3300 for Arm [A] and 2300 for Arm [B], which will provide >90% power to detect non-inferiority of low-dose iv rt-PA and superiority of intensive BP lowering on the primary clinical outcome, respectively.

Conclusions

Low-dose iv rt-PA and early intensive BP lowering could provide more affordable and safer use of thrombolysis treatment for patients with AIS worldwide.

Glycemic associations with endothelial function and biomarkers among 5 ethnic groups: the Multi-Ethnic Study of Atherosclerosis and the Mediators of Atherosclerosis in South Asians Living in America studies

Background

The association of prediabetic states with endothelial dysfunction measured by flow‐mediated dilation (FMD) or endothelial biomarker levels remains controversial. We examined data from 5 ethnic groups to determine the association between glucose categories and FMD or endothelial biomarkers. We determined whether these associations vary by ethnic group or body mass index.

Methods and Results

We used data from 3516 participants from 5 race/ethnic groups with brachial FMD, endothelial biomarkers, and glucose category (normal, impaired fasting glucose [IFG], and diabetes) measures. There were significant ethnic differences in FMD, biomarker levels, and the prevalence of IFG and diabetes. However, all 5 ethnic groups showed similar patterns of higher FMD for the IFG group compared with the normal glucose and diabetes groups, which was most significant among whites and Asian Indians. Associations between glucose categories and endothelial biomarkers were more uniform, with the IFG and diabetes groups having higher biomarker levels than the normal glucose group. These associations did not change with further adjustment for fasting insulin levels. Whites with normal BMI had higher FMD values with higher glucose levels, but those with BMI in the overweight or obese categories had the inverse association (P for interaction=0.01).

Conclusions

The discordance of IFG being associated with higher FMD but more abnormal endothelial biomarker levels is a novel finding. This higher FMD for the IFG group was most notable in whites of normal BMI. The higher FMD among those with impaired fasting glucose may reflect differences in insulin signaling pathways between the endothelium and skeletal muscle.

Intravenous thrombolysis for acute ischemic stroke in Asia

Data regarding thrombolysis for acute ischemic stroke in Asia are scarce and only a small percentage of patients are thrombolysed. Clinical trials that led to the recommended dose of intravenously administered tissue plasminogen activator (IV-tPA) included predominantly Caucasian patients. However, the single-arm case-controlled observational studies in Japanese patients suggested the clinical efficacy and safety of low-dose IV-tPA (0.6 mg/kg bodyweight; maximum 60 mg) comparable with standard dose (0.9 mg/kg bodyweight; maximum 90 mg). There has been no randomized clinical trial for determining the dose, efficacy or safety of IV-tPA in Asia. Accordingly, the dose of IV-tPA in Asia remains controversial. Reduced treatment cost, lower symptomatic intracerebral hemorrhage risk and comparable efficacy encouraged many Asian centers to adopt low-dose or even variable-dose IV-tPA regimens. We present the current status of thrombolysis for acute ischemic stroke in Asia.

Diet and haemostatic processes

Diet plays an important role in the primary and secondary prevention of cardiovascular disease. The growing perception that abnormal haemostatic processes of coagulation, platelet aggregation and fibrinolysis contribute to cardiovascular disease aetiology motivated this review on the relationships of diet, specific foods and nutrients with haemostatic function. Functional endpoints that reflect the function and status of some of these processes and which can be measured in dietary trials are identified. The effects of energy intake and expenditure, alcohol, total fat and specific fatty acids, non-starch polysaccharides (dietary fibre), antioxidant nutrients and some foods on a variety of haemostatic markers are reviewed. The results indicate that the prudent low-fat, high-fibre diet and maintenance of ideal body weight recommended to protect against and treat hyperlipidaemia and coronary heart disease will also benefit haemostatic profiles. It is concluded that more research on specific effects is needed for improved recommendations on a population level for prevention of cardiovascular disease.

Plasma hemostatic factors and endothelial markers in four racial/ethnic groups: the MESA study

BACKGROUND

Hemostatic factors and endothelial markers may play some role in racial/ethnic differences in cardiovascular disease (CVD) rates. However, little information exists on hemostatic factors and endothelial markers across racial/ethnic groups.

OBJECTIVES

To describe, in four American racial/ethnic groups (Caucasian, Black, Hispanic, and Chinese), mean levels of selected hemostatic factors and endothelial markers.

PATIENTS AND METHODS

Multi-ethnic Study of Atherosclerosis baseline data were used (participant age: 45-84 years). Sex-specific analysis of covariance models, and t-tests for pairwise comparisons, were used to compare means of factors and markers. Adjustments were made for demographics and traditional CVD risk factors. Differences were significant at P < 0.05.

RESULTS

Blacks had the highest levels of factor VIII, D-Dimer, plasmin-antiplasmin (PAP), and von Willebrand factor, among the highest levels of fibrinogen and E-selectin (women only), but among the lowest levels of intercellular adhesion molecule 1 (ICAM-1), and, in men, the lowest levels of plasminogen activator inhibitor-1 (PAI-1). Whites and Hispanics tended to have intermediate levels of factors and markers, although they had the highest levels of ICAM-1, and Hispanics had the highest mean levels of fibrinogen and E-selectin (women only). Chinese participants had among the highest levels of PAI-1, but the lowest, or among the lowest, of all other factors and markers. No soluble thrombomodulin differences were observed.

CONCLUSIONS

In this large cohort, hemostatic factor and endothelial marker mean levels varied by race/ethnicity, even after adjustment for traditional CVD risk factors.

The determinants of plasma plasminogen activator inhibitor-1 levels differ for American and Japanese men aged 40-49

BACKGROUND

Elevated plasma plasminogen activator inhibitor-1 (PAI-1) levels were associated with higher incidence of type II diabetes. Elucidating the determinants of PAI-1 in various ethnicities may help to understand the susceptibility to developing diabetes. The aim of our study was to compare PAI-1 levels between Americans and the Japanese in the post-war generation and to elucidate the determinants of the PAI-1 levels.

METHODS

We conducted a cross-sectional study on a total of 198 men aged 40-49 in the US (Body mass index (BMI): 27.0+/-3.3 kg/m(2)) and Japan (BMI: 23.3+/-3.1 kg/m(2)). Examination included physique measurement (BMI and waist girth), blood analysis (lipid profiles, glucose, insulin, C-reactive protein, and PAI-1), and life-style assessment by self-administered questionnaires.

RESULTS

PAI-1 levels were significantly lower in American than in Japanese men, even after adjustment for age, waist girth, cigarette smoking, habitual alcohol drinking, and other factors. In the Americans, waist girth, insulin, and cigarette smoking were significantly associated with PAI-1 levels, while waist girth and triglycerides were significantly associated with PAI-1 levels in the Japanese.

CONCLUSIONS

PAI-1 levels were significantly lower in American than in Japanese men and the determinants of PAI-1 levels differ for American and Japanese men aged 40-49.

Acute ingestion of red wine by men activates platelets but does not influence endothelial markers: no effect of white wine

Long-term moderate alcohol use is associated with a better cardiovascular risk profile than total abstinence, although the short-term effect of a bolus of alcohol is unclear. The hypothesis tested in this study was that an acute bolus of alcohol would adversely affect the endothelium and platelets. Blood was taken before and 4 h after the ingestion of red or white wine by nine volunteers per group, and by 11 control water-only drinkers at the same time points. Plasma was obtained and markers of platelet activity (beta-thromboglobulin and soluble P selectin) and endothelial cell function (von Willebrand factor and soluble thrombomodulin) measured by enzyme-linked immunosorbent assay. The only marker to change significantly was beta-thromboglobulin, which increased from a median of 10 ng/ml (interquartile range, 8.5-15) before drinking red wine to 16 ng/ml (interquartile range, 14-20) 4 h later (P = 0.0067). We conclude that an acute bolus of red wine, but not white wine, activates platelets but has no substantial effect on the endothelium.

Coronary heart disease mortality among men aged 35-44 years by prefecture in Japan in 1995-1999 compared with that among white men aged 35-44 by state in the United States in 1995-1998: vital statistics data in recent birth cohort

The levels of risk factors for coronary heart disease (CHD) in men in the post World War II (WWII) birth cohort are almost similar between Japan and the USA, except for the considerably higher prevalence of cigarette smoking in Japan and the much higher prevalence of obesity in the USA. The present study evaluated the CHD mortality among men in the post WWII birth cohort by prefecture in Japan in 1995-1999 and then compared the data with those for white men in different states in the USA. There was a greater than 2-fold difference in CHD mortality among men aged 35-44 by prefecture in Japan: 5.3/100,000 in Kumamoto vs 12.6/100,000 in Tochigi. CHD mortality among men aged 35-44 in the top 3 prefectures in Japan is about half that of white men in the USA and is similar to that of white men in the lowest 3 states. The much lower CHD mortality in Japan does not appear to be caused by differences in the classification of causes of death and the results suggest that there may be strong and important protective factors that reduce the risk of CHD in Japan.

A randomized trial confirming the efficacy of reduced dose recombinant tissue plasminogen activator in a Chinese myocardial infarction population and demonstrating superiority to usual dose urokinase: the TUCC trial

BACKGROUND

Reports from Japan suggest effective myocardial infarction (MI) treatment in Asian patients with much lower doses of tissue plasminogen activators (tPA) than used in European and American regimens. Because increasing doses of fibrinolytics lead to increased bleeding complications, identification of patients who respond to reduced doses is of importance. We conducted a trial in the People's Republic of China in which reduced-dose recombinant tPA was compared with the standard local therapy, urokinase.

METHODS

Four hundred patients with acute MI within 12 hours of symptom onset were to be randomized to an 8-mg bolus of recombinant tPA followed by a 42-mg 90-minute infusion or 1.5 million units of urokinase as a 30-minute infusion. Patients received aspirin and heparin and underwent angiography to determine infarct artery patency 90 minutes after the start of therapy.

RESULTS

The Data and Safety Monitoring Board recommended premature termination after 342 patients were recruited. Infarct artery patency (grade 2 or 3) occurred in 79% of patients receiving recombinant tPA and in 53% of patients receiving urokinase (P <.001); Thrombolysis in Myocardial Infarction (TIMI) grade 3 flow was 48% and 28%, respectively (P <.001). The higher-patency-rate recombinant tPA growth had better posttreatment left ventricular ejection fractions, 58.6% versus 54.7%, P <.01. Adverse events were infrequent and not significantly different in the 2 groups.

CONCLUSIONS

This study confirms that a substantially lower dose of recombinant tPA is effective in Asian patients compared with that required in Western patients even after consideration of body weight. Specific dose-response studies should be performed with fibrinolytic regimens to avoid overdosage with its attendant risks of excess bleeding.

Overweight/obesity, smoking, and heavy alcohol consumption are important determinants of plasma PAI-1 levels in healthy men

BACKGROUND

Plasma plasminogen activator inhibitor-1 (PAI-1) is thought to contribute to the pathogenesis of atherosclerosis and is a predictor of ischemic heart disease.

METHODS

We investigated the effects of overweight/obesity and lifestyle (smoking and alcohol intake) on plasma PAI-1 levels in 203 healthy men (age 44.5+/-8.1) who visited our department for health check. Information on alcohol intake and smoking habit was obtained by a questionnaire.

RESULTS

Plasma PAI-1 was significantly correlated to plasma leptin, body mass index (BMI), percent body fat, plasma levels of triglyceride, and gamma-glutamyl transpeptidase. Plasma PAI-1 was also increased significantly in smokers and in heavy drinkers. Plasma PAI-1 levels increased in an additive manner by the combination of risk factors (BMI > or =25 kg/m2, smoking, and heavy alcohol consumption). Nonobese, nonsmoking, nondrinkers showed the lowest plasma PAI-1 levels, whereas overweight/obese, smoking, heavy drinkers showed the highest levels (11.2+/-2.2 ng/mL versus. 34.0+/-4.3 ng/mL, P < 0.0001).

CONCLUSIONS

These results suggest that overweight/obesity and unfavorable lifestyle such as smoking and heavy alcohol consumption may increase plasma PAI-1 levels and might be linked to the risk of ischemic heart disease.

Increased plasma fibrinolysis and tissue-type plasminogen activator/tissue-type plasminogen activator inhibitor ratios after ethanol withdrawal in chronic alcoholics

The effects of alcohol withdrawal on fibrinolysis were studied in 10 middle-aged male chronic alcoholics institutionalized for withdrawal therapy. All patients were sampled on admission [day 1 (D1)] and 21 days after alcohol withdrawal [day 22 (D22)]. The overall plasma fibrinolytic capacity (OFC) was assayed by measuring the ability of patient plasma to generate D-dimers from a standardized fibrin clot, and tissue-type plasminogen activator (t-PA) and t-PA inhibitor (PAI-1) levels were assayed together with serum cholesterol, triglyceride and cholesterol fractions. At D22, the OFC significantly increased in seven patients [D1 = 10 +/- 0.7 microg/h (mean +/- SD), D22 = 17 +/- 7.4 microg/h; P < 0.01], while t-PA and PAI-1 levels decreased in all patients but two (t-PA: D1 = 16.6 +/- 5 ng/ml, D22 = 10.2 +/- 3.8 ng/ml; P < 0.001; and PAI-1: D1 = 46 +/- 39 ng/ml, D22 = 21 +/- 28 ng/ml; P < 0.01). This study clearly demonstrates an increase in overall fibrinolytic activity after alcohol withdrawal, which is mainly due to a decrease in PAI-1 levels. These changes induced by alcohol abstinence might provide clear benefit by reducing the risk of thromboembolic events and particularly of stroke associated with elevated PAI-1 levels described in heavy drinkers.

Alcohol consumption and plasminogen activator inhibitor type 1: the National Heart, Lung, and Blood Institute Family Heart Study

BACKGROUND

Plasminogen activator inhibitor type 1 (PAI-1) plays a key role in fibrinolytic activity, which is important for thrombotic cardiovascular events. It has been suggested that moderate alcohol consumption may protect against coronary heart disease and ischemic stroke. However, little is known about the effects of moderate doses of alcohol on PAI-1.

METHODS AND RESULTS

We assessed the association between different levels of alcohol consumption and PAI-1 among 1862 participants of the National Heart, Lung, and Blood Institute Family Heart Study. We fitted a regression model, adjusting for anthropometric, metabolic, and lifestyle factors. Individuals in the highest alcohol intake category were leaner, had higher high-density lipoprotein cholesterol levels, smoked more cigarettes, and consumed less dietary fiber compared with never-drinkers. For drinking categories of never-drinkers, ex-drinkers, and current drinkers of 0.1 to 1.4, 1.5 to 4.9, 5.0 to 14.9, and > or =15 g/d of alcohol, multivariate adjusted geometric mean PAI-1 levels among women were 10.77, 9.41, 9.99, 11.21, 11.28, and 16.40 ng/mL, respectively. With similar categories except the top category divided into 15.0 to 29.9 and > or =30 g/d, PAI-1 levels among men were 18.43, 15.77, 15.19, 16.20, 17.27, 24.02, and 29.46 ng/mL, respectively.

CONCLUSIONS

These results show that alcohol consumption up to 14.9 g/d is not associated with increased PAI-1, whereas the findings suggest increased PAI-1 with greater alcohol intake.

Plasma Concentration of Endogenous Tissue Plasminogen Activator and the Occurrence of Future Cardiovascular Events

Data from recent prospective studies of hemostasis and thrombosis indicate that the plasma concentration of endogenous tissue-type plasminogen activator (tPA) is often elevated years in advance of a first arterial occlusion. Specifically, among healthy subjects with no prior cardiovasacular disease, the risk of future myocardial infarction and stroke appears to be three to four times higher among subjects with high baseline levels of tPA antigen as compared to subjects with lower levels. Whether this relationship represents activation of the endogenous fibrinolytic system in response to the presence of preclinical atherosclerosis or is a reflection of elevated concentrations of local plasminogen activator inhibitors is currently unresolved. However, cross-sectional data indicate that the plasma concentration of IPA antigen is related to several traditional atherosclerotic risk factors, including HDL cholesterol, findings that further support a direct relationship between endogenous IPA and vascular risk. In concert with data concerning the primary inhibitors of plasminogen activation, it has been hypothesizd that the endogenous fibrinolytic system varies within the general population such that certain individuals are prone to thrombosis, whereas others may be prone to hemorrhage. Thus, observations regarding fibrinolytic activation and inhibition raise the possibility that assessment of the intrinsic fibrinolytic system may prove useful in identifying individuals at increased risk for vascular thrombosis. In addition, available findings suggest that therapeutic agents capable of favorably shifting the net filerinolytic balance may provide a new strategy for cardiovascular disease prevention.

Alcohol and lipids

Alcoholic fatty liver and hyperlipemia result from the interaction of ethanol and its oxidation products with hepatic lipid metabolism. An early target of ethanol toxicity is mitochondrial fatty acid oxidation. Acetaldehyde and reactive oxygen species have been incriminated in the pathogenesis of the mitochondrial injury. Microsomal changes offset deleterious accumulation of fatty acids, leading to enhanced formation of triacylglycerols, which are partly secreted into the plasma and partly accumulate in the liver. However, this compensatory mechanism fades with progression of the liver injury, whereas the production of toxic metabolites increases, exacerbating the lesions and promoting fibrogenesis. The early presence of these changes confers to the fatty liver a worse prognosis than previously thought. Alcoholic hyperlipemia results primarily from increased hepatic secretion of very-low-density lipoprotein and secondarily from impairment in the removal of triacylglycerol-rich lipoproteins from the plasma. Hyperlipemia tends to disappear because of enhanced lipolytic activity and aggravation of the liver injury. With moderate alcohol consumption, the increase in high-density lipoprotein becomes the predominant feature. Its mechanism is multifactorial (increased hepatic secretion and increased extrahepatic formation as well as decreased removal) and explains part of the enhanced cholesterol transport from tissues to bile. These changes contribute to, but do not fully account for, the effects on atherosclerosis and/or coronary heart disease attributed to moderate drinking.

Diet and haemostasis: time for nutrition science to get more involved

Abnormal haemostasis, and specifically a pre-thrombotic state characterized by hypercoagulability, increased platelet aggregation and impaired fibrinolysis, is associated with increased atheroma and thrombosis. The recent literature clearly indicates that diet may prevent or be used to treat some abnormal haemostatic states. There are reports on effects of energy intake and expenditure, alcohol consumption, intakes of total fat, different fatty acids, fish oil, NSP and vitamins on markers of coagulation, platelet function and fibrinolysis. Some of the confusion and controversy in this field has arisen because the wrong markers of haemostasis have been measured in dietary trials. Moreover, many of the studies have lacked good dietary control. It is suggested that more sensitive, functional markers of the balance between the different facets of the haemostatic system should be measured. It is also important to test hypotheses developed from known observations and to propose mechanisms of action of the various dietary factors, based on our improved understanding of the haemostatic system.

Fibrinolytic factors and the risk of myocardial infarction or sudden death in patients with angina pectoris. ECAT Study Group. European Concerted Action on Thrombosis and Disabilities

BACKGROUND

Disturbances of the fibrinolytic system that lead to decreased removal of fibrin deposits may be important risk factors for coronary thrombosis. There is as yet no consensus on the prognostic value of fibrinolytic parameters, which may be attributed in part to the choice of confounding variables controlled for.

METHODS AND RESULTS

The ECAT study is a prospective multicenter study of 3043 patients with angina pectoris followed for 2 years. Baseline measurements included 10 fibrinolytic variables. The results were analyzed in relation to the subsequent incidence of myocardial infarction or sudden coronary death. They are presented before and after adjustment for clusters of confounding variables that are markers of different mechanisms: insulin resistance (body mass index, triglyceride, and HDL cholesterol), inflammation (fibrinogen and C-reactive protein), and endothelial cell damage (von Willebrand factor). An increased incidence of events was associated with higher baseline concentrations of tissue plasminogen activator (TPA) antigen (P = .0002), plasminogen activator inhibitor-1 (PAI-1) activity (P = .02), and PAI-1 antigen (P = .001). The associations of PAI-1 activity and PAI-1 antigen with risk of events disappeared after adjustment for parameters reflecting insulin resistance but were not affected by other adjustments. TPA antigen was affected to a similar extent by adjustment for parameters reflecting insulin resistance. Inflammation, or endothelial cell damage, but the risk association disappeared only after combined adjustments.

CONCLUSIONS

The prognostic role of PAI-1 in predicting coronary events is related principally to insulin resistance, whereas that of TPA antigen could be explained only by its relationship with different mechanisms, including insulin resistance, inflammation and endothelial cell damage.

Lipoprotein(a) and its correlates in Japanese and U.S. population samples

To examine whether serum levels of lipoprotein(a) [Lp(a)], a potential coronary risk factor, are higher in Caucasian-Americans than in Japanese, a circumstance that would correspond to the higher mortality from coronary heart disease in the United States than in Japan, we analyzed serum Lp(a) levels in 300 nonsmoking men and women aged 47-69 years. Participants were drawn from two population-based samples: rural Japanese living in Akita and Caucasians living in Minneapolis-St. Paul, MN. Geometric mean and median serum Lp(a) concentrations were higher (P < 0.05) in Japanese than in Caucasians for both men (difference in geometric mean = 3.2 mg/dL) and women (difference = 5.3 mg/dL). There was however, no racial difference in the proportion of elevated Lp(a) concentrations (i.e., > or = 30 mg/dL) in either sex. Alcohol intake was inversely correlated with Lp(a) levels in Japanese men, who had a high average alcohol intake, but not in other sex and racial groups. Serum Lp(a) was nonsignificantly but consistently correlated with plasma fibrinogen and LDL-cholesterol for all sex and racial groups. With adjustment for alcohol intake, LDL-cholesterol, and plasma fibrinogen, the Japanese-Caucasian difference in geometric mean Lp(a) values was even larger for men and was not changed for women. Results of the present study do not support the hypothesis that racial differences in Lp(a) concentrations contribute to the higher mortality rate from coronary heart disease in the United States than in Japan.

Beyond alcohol: beverage consumption and cardiovascular mortality

This paper reviews epidemiological investigations which have identified an inverse relationship between alcohol consumption and death from coronary heart disease: evidence from studies of mixed populations as well as of single-sex populations have, on the whole, demonstrated that this relationship is independent of sex or age. This 'cardioprotective effect' of alcohol can be explained, at least in part, by ethanol-related increases in high density lipoprotein cholesterol and reduced platelet coagulability. With certain beverages, especially red wine, phenolic compounds may provide additional protection by altering eicosanoid metabolism in favour of increased prostacyclin and decreased thromboxane synthesis, as well as antioxidant functions which prevent the peroxidation of low-density lipoprotein. Trans-resveratrol, a tri-hydroxy stilbene present in the skins of specific grape cultivars, is a constituent of certain red wines which may play a crucial role in modulating lipoprotein metabolism, eicosanoid synthesis, oxidation and coagulation. Preliminary studies using the human hepatoma cell line HepG2 are described, demonstrating that this compound has no effect upon cell viability or overall protein synthesis in these cells, and at high concentrations DNA synthesis as measured by radioactive thymidine incorporation is enhanced. Reduced intracellular concentration and secretion of apolipoprotein B have been shown to occur in response to resveratrol although a clear dose-dependency has not yet been demonstrated. The mechanisms underlying these changes as well as the effects upon the synthesis and secretion of other apolipoproteins are under active investigation in our laboratory.

Tissue-plasminogen activator, plasminogen activator inhibitor and risk of peripheral arterial disease

In this population-based case-control study, we examined the relationship between the fibrinolytic variables tissue-plasminogen activator (t-PA) antigen and plasminogen activator inhibitor (PAI) activity, cardiovascular risk factors and peripheral arterial disease. Cases and controls were selected from the Edinburgh Artery Study, a random sample survey of men and women, aged 55-74 years. Mean levels of t-PA antigen and PAI activity were significantly elevated in 121 cases compared to 126 controls. The increased risks of peripheral arterial disease with increasing PAI activity and t-PA antigen levels were partly mediated by interactions with serum triglycerides, high density lipoprotein (HDL) cholesterol and cigarette smoking. For example, adjustment for triglycerides significantly reduced the odds of disease for PAI activity from 1.41 (95% confidence intervals 1.08, 1.86) to 1.24 (0.93, 1.65) and from 1.47 (1.09, 1.98) to 1.34 (0.99, 1.82) for t-PA antigen. We conclude that impaired fibrinolytic potential (raised PAI activity and t-PA antigen) is associated with peripheral atherosclerosis and that this relationship is partly influenced by lipids and cigarette smoking.