Fruit and vegetables and cardiovascular risk profile: a diet controlled intervention study

OBJECTIVE

To evaluate the effect of fruit and vegetables consumption on markers of risk for cardiovascular disease.

DESIGN

Randomised, diet controlled, parallel study.

SUBJECTS

Forty-eight apparently healthy (40--60 y) volunteers with a low usual consumption of fruit and vegetables. Forty-seven of them completed the study.

INTERVENTIONS

During 4 weeks 24 volunteers consumed a standardised meal, consisting of 500 g/day fruit and vegetables and 200 ml/day fruit juice ('high' group) and 23 volunteers consumed 100 g/day fruit and vegetables ('low' group) with an energy and fat controlled diet.

RESULTS

Final total cholesterol was 0.2 (95% CI -0.5--0.03) mmol/l lower in the high group than in the low group (P>0.05). Final fibrinogen and systolic blood pressure were 0.1 (-0.1--0.4) g/l and 2.8 (-2.6--8.1) mmHg higher in the high group than in the low group (P>0.05), respectively. Also, other final serum lipid concentrations, diastolic blood pressure and other haemostatic factors did not differ between both groups.

CONCLUSIONS

This was a small randomised well-controlled dietary intervention trial of short duration with a considerable contrast in fruit and vegetable consumption. No effects on serum lipids, blood pressure and haemostatic variables were observed.

A Common Calibrator Does Not Secure Harmonisation of Commercial t-PA and PAI-1 Antigen Measurements

There is no common standardisation of different commercially available kits for both t-PA and PAI-1 antigen.

AIM

The aim of this project was to study whether the exchange of the kit calibrator with the common calibration materials of the WHO would harmonise the results produced by five different commercially available t-PA and PAI-1 antigen kits when analysing the SSC secondary standard.

METHODS

WHO international standards were used as calibrator and the SSC secondary standard and a commercially available plasma standard were used as test plasma in 5 commercially available kits measuring total t-PA and PAI-1 antigen. For t-PA only, the SSC secondary standard was spiked with purified t-PA and recovery was studied.

RESULTS

There was a large variation in the concentrations of t-PA antigen (ranging from <0.5 to 6.6 ng/ml for the SSC secondary standard and from 3.3 to 10.9 ng/ml for the commercial plasma standard, respectively) produced by the different kits. Also, PAI-1 antigen results of the different kits showed a large variation (ranging from 20.3 to 51.2 ng/ml for the SSC secondary standard and from 41.8 to 89.7 ng/ml for the commercial plasma standard, respectively). Results of the two test samples and spiking with t-PA were not in agreement in all methods, indicating differences in specificity of tests. Data point to a specific effect of the matrix of standards.

CONCLUSIONS

The use of a common calibration material does only marginally harmonise data for t-PA and PAI-1 antigen assays. There is a need for improvement of methods to cope with standards and standardisation.

Performance of semiquantitative and quantitative D-dimer assays in the ECAT external quality assessment program

D-dimer levels are used in clinical practice as markers for the presence or exclusion of venous thrombosis. Therefore, it is important that the performance of the D-dimer tests is well controlled. One of the components of a laboratory quality program is external quality assessment (EQA). The main aim of EQA is to identify the degree of agreement among laboratories. In addition to identifying the individual laboratory performance, it also identifies the characteristics of the different reagents and methods that are used in different laboratories. Recently, the D-dimer test was included in the ECAT External Quality Assessment program. Eighty-one laboratories in four rounds applied semiquantitative and quantitative D-dimer assays to three samples (concentrations normal, slightly elevated, and elevated). Although the reported values varied widely, the classification of the samples was mostly correct for the normal and the elevated samples. The slightly elevated sample was classified as normal by all laboratories using semiquantitative methods and by 60% of the laboratories using quantitative methods, and this varied between 45% and 86% for the different methods. In conclusion, D-dimer methods show a large variation, and the quality of the D-dimer assessment could be improved by standardization and by using cut-off ranges.

Fibrin clot formation and lysis: basic mechanisms

The hemostatic balance, introduced more than 40 years ago, addresses the components and reactions involved in fibrin turnover. Fibrin is placed in the core of this delicate balance. Defects in the mechanisms responsible for fibrin turnover might lead to thrombosis or bleeding, and fibrin consequently is an important substrate in the physiology of hemostasis. This review describes the components and processes involved in fibrin formation and fibrin degradation. Particular emphasis is put on the reactions involved in the conversion of fibrinogen to fibrin, the polymerization of fibrin molecules induced by coagulation factor XIII (FXIII), and the degradation of fibrinogen and fibrin mediated by plasmin and elastase. Furthermore, factors influencing fibrin structure and fibrin breakdown are addressed; in particular polymorphisms in the genes coding for fibrinogen and FXIII, but also the physical and biochemical conditions in which fibrin is formed. The past decades have produced a bulk of biochemical publications reviewing fibrin turnover and fibrin structure, and it has been shown that alterations in fibrin structure are important for the development of various disease conditions, whereas, the architecture of fibrin can be modified by certain drugs and chemical compounds. However, these topics deserve increased attention in clinical settings. Of particular importance might be more detailed clinical studies that review the influence of polymorphisms in the genes coding for the key factors involved in fibrin metabolism on the development of hemostatic diseases, but also the role of elastase-induced fibrin degradation deserves increased attention.

Determinants of C-reactive protein concentration in blood

C-reactive protein (CRP) is a very strong acute phase protein. During the acute phase of disease the CRP concentration can increase up to a thousand-fold. However, a higher CRP concentration is also observed during chronic stages of disease, for example in subjects with chronic bronchitis, periodontal disease or subjects with increased titers of Helicobacter pylori or Chlamydia pneumoniae. The concentration of CRP is also reported to be associated with age, sex, race, smoking, obesity, consumption of coffee and alcohol, stress, physical training, lipid levels, and blood pressure. Statins decrease the CRP concentration whereas estrogen increases it. With regard to most other drugs no consistent relationship has been reported.

Determination of the habitual low blood level of C-reactive protein in individuals

In order to use C-reactive protein (CRP) in risk prediction in individuals, it is necessary to know how to obtain the habitual level of an individual and hence its biological variations: i.e. longitudinal variability within subjects and variability between individuals. This paper provides data on biological variability that is used to propose a strategy for assessing individual low levels of CRP. The longitudinal variability in individuals (intraindividual variability) is essential to know, but only reported in a very limited way. Additional data were calculated from in-house and requested databases for periods of follow-up from 5 days to 1 year. The intraindividual coefficient of variation (CVi) was found to be rather similar for several groups and periods and on average was approximately 30%. Reported analytical coefficients of variation of commercial and in-house methods generally are below 6%, which is well below the desired limit of half the CVi. The distribution of CRP in apparently healthy individuals is wide and skewed with interquartile values ranging between 150-250% of the median and an estimate of the composite coefficient of variation (CVc) of approximately 120%. The distribution is equally broad in several other groups studied such as type II diabetics and pregnant women. It is concluded that the coefficient of variation for the determination of CRP in a single blood sample is as high as approximately 30%, but that this is acceptable for the reliable positioning of individuals within the distribution of CRP in the group with a CVc as high as -120%. CRP can show unexpected outliers (increases) which can sometimes be explained by information from a short questionnaire and definitely identified by the analysis of a second blood sample after an interval of approximately 2 weeks. Similarly, to ascertain high values in a first sample a second blood sample can be analyzed. It should be noted that, in view of the significant intraindividual variability of CRP, the difference between the first and second values may reach 71%. The large intraindividual variability of CRP approximating 30% renders it difficult to position an individual reliably in smaller categories such as tertiles, quartiles or quintiles of the total distribution. It is suggested that it would be most practical to have a goal of a single decision level or threshold only. Positioning an individual into two groups with equally wide distribution is on the borderline of reliability for one blood sample. Multiple blood samplings are required for smaller categories and higher threshold levels. The use of a decision limit should further acknowledge the limited interclass stability of around r = approximately 0.5 for a single blood sample. The above considerations are summarized in a practical working scheme. This scheme can serve as a basis for further refinement, discussions and development of sampling and decision limits to be selected from medical and economical perspectives and tested in practice.

Activation products of the haemostatic system in coronary, cerebrovascular and peripheral arterial disease

To determine the presence of a 'hypercoagulable state' as assessed by indices of thrombin and plasmin generation and of the amount of fibrin that is lysed, in patients with stable coronary, cerebral and peripheral arterial disease a population-based cross-sectional study was performed. From a population-based cohort comprising 7983 men and women aged 55 years and over, we randomly selected 127 subjects with a history of myocardial infarction, 124 with a history of stroke and/or transient ischemic attack, 131 patients with peripheral arterial disease and 263 control subjects in the same age group without arterial disease. Subjects using anticoagulant drugs were not selected. F1+2, TAT, and PAP were not associated with a history of cardiovascular events, nor with peripheral arterial disease. In contrast, positive associations were found for D-Dimer. Mean D-Dimer level was 40 microg/l (95% CI 35, 44) in control subjects; 53 microg/l (47, 61) in those with a history of myocardial infarction and 51 microg/l (45, 58) in those with a history of stroke and or transient ischemic attack. D-Dimer increased gradually with increasing severity of peripheral atherosclerosis; a decrease in ankle/arm systolic blood pressure ratio of 0.1 was associated with an increase in D-Dimer of 3.9 microg/l (p<0.01). This was more pronounced in subjects with higher F1+2, TAT and PAP concentration. In conclusion, the markers of onset of coagulation F1+2, TAT and PAP are not associated with the presence of arterial disease, but increased levels of these markers are necessary for the positive association between D-Dimer and arterial disease.

Antibodies to Chlamydia pneumoniae and clinical course in patients with unstable angina pectoris

Inflammation is one of the most important mechanisms that contribute to coronary artery disease (CAD). One of the micro-organisms that is mentioned as a source of the inflammation is Chlamydia pneumoniae. In this study, we investigated the relationship between titres of IgG and IgA antibodies to C. pneumoniae and the clinical course, during hospitalisation and during an 18-month follow-up, in 211 patients admitted to hospital with unstable angina pectoris. Slightly more patients who were refractory during their hospitalisation were positive for C. pneumoniae antibodies than patients who could be stabilised by drug treatment (53 vs. 43%, for IgG and 16 vs. 11% for IgA, respectively)(n.s.). In logistic regression analysis no significant predictive values were observed for the relationship between antibody titres and clinical course. The antibody titres to C. pneumoniae were lower in the unstable angina patients who had plasma levels of interleukin-10 (IL-10) above 5 pg/ml than in the patients with levels below 5 pg/ml, and higher in smokers than in non-smokers. No associations were observed between antibody titres to C. pneumoniae and C-reactive protein (CRP), interleukin-6 (IL-6), age, total cholesterol levels, fibrin degradation products (FDP), plasminogen activator inhibitor-1 (PAI-1) and erythrocyte sedimentation rate (ESR). In conclusion, there was no significant association between antibody titres to C. pneumoniae and risk of events during hospitalisation and the 18-month follow-up period in patients admitted for unstable angina pectoris.

Consumption of black and green tea had no effect on inflammation, haemostasis and endothelial markers in smoking healthy individuals

OBJECTIVE

Firstly, to study the effect of tea and tea polyphenols on cardiovascular risk indicators of the inflammatory system (IL6, IL1beta and TNF-alpha, CRP), and on haemostasis and endothelial proteins with an acute phase behaviour (fibrinogen, vWF, PAI-1, FVIIa and u-PA). Secondly, to study the relationship between plasma levels of antioxidants (alpha-tocopherol, beta-carotene and vitamin C) and these acute-phase, cardiovascular risk indicators.

DESIGN

Randomized study.

SUBJECTS

Sixty-four smoking healthy volunteers were recruited by newspaper advertisements; there were five dropouts.

INTERVENTION

Four-week administration of black tea, green tea, green tea polyphenol isolate and mineral water ( 13-16 per group).

MEASURES

Plasma levels of the inflammatory markers IL6, IL1beta, TNF-alpha, CRP, fibrinogen, vWF, PAI-1, FVIIa and u-PA and of the antioxidants alpha-tocopherol, beta-carotene and vitamin C.

RESULTS

Different dosages of tea polyphenols had no effect on inflammation, haemostasis and endothelial markers. There was a significant negative correlation between the levels of the antioxidant beta-carotene and the inflammation markers IL6 and fibrinogen (r = -0.35 and r = -0.37, respectively, P<0.01) in this group of smokers. Remarkably, there was a significant positive correlation between the levels of the antioxidant alpha-tocopherol and the inflammation marker IL6 (r = 0.28, P<0.05).

CONCLUSIONS

Tea drinking had no effect on the levels of the inflammation, haemostasis and endothelial cardiovascular risk factors measured. We did observe a relationship between the antioxidant variables alpha-tocopherol and beta-carotene and inflammation markers in this group of healthy smoking subjects.

Criteria and Search for Specific Assays for Active Plasminogen Activator Inhibitor 1 (PAI-1) in Plasma

BACKGROUND

Proficiency testing of enzymatic methods for plasminogen activator inhibitor 1 (PAI-1) showed a systematic variability indicating the aspecificity of some methods.

METHODS

To define and detect specificity of enzymatic methods for PAI-1, experts of the ISTH/SSC subcommittee defined criteria and test samples to check the criteria. 16 samples were prepared to test (a) specificity in depleted plasma, (b) interference by added PAI-2 or PAI-3, (c) interference by added tissue-type plasminogen activator (t-PA), (d) performance in dose response. To exercise the test procedure participants were recruited via the subcommittee, literature and company data. Coded samples were distributed to participants. The NIBSC standard for PAI-1 activity was included for the normalisation of results. Adherence to the predetermined criteria was judged blind in the ISTH/SSC subcommittee meeting.

RESULTS

In total 17 laboratories with 15 different assay methods participated in the study. Methods were based on four detection principles. 8 methods failed to detect sufficiently low activity in depleted plasma and were sensitive to added PAI-2. 10 methods were sensitive to interference by endogenous t-PA as revealed by additions of t-PA. Not all methods could adequately measure in acidified plasma. Two methods were fulfilling all the criteria.

CONCLUSIONS

Most methods were not specific for PAI-1 (enz. procedure) in acidified plasma. Definition of criteria and test methods by experts of the ISTH/SSC proved a valuable concept, according to the exercise undertaken.

Effects on haemostasis variables by second and third generation combined oral contraceptives: a review of directly comparative studies

Previous reports and reviews indicate differences in effects of second and third generation combined oral contraceptives (COCs) on haemostasis variables. This review analyses directly comparative studies on such effects. From the literature, 17 longitudinal comparative studies with parallel groups were retrieved, containing data on comparisons between COCs containing levonorgestrel (second generation COCs) and COCs containing desogestrel, gestodene or norgestimate (third generation COCs) with 30-35 ug ethinylestradiol. Six or more comparisons were available only for fibrinogen, platelet count, antithrombin III, factor VII, factor VIII and factor X. The comparisons reveal a consistently larger increase in factor VII with the third generation COCs compared to the second generation COCs. The effects on factor VII do not coincide in these comparative studies with effects on factor X and prothrombin, rendering a specific sensitivity of the vitamin K-dependent mechanisms for progestogens unlikely. Fibrinogen effects tend to be different for the different progestogens, suggesting a progestogen-specific dependence. Trends in antithrombin III are towards more reduction for the third generation COCs, but the effects are very minor. The effects on factor V suggest a possible progestogen specificity, which may be relevant to explain the difference in APC-resistance between second and third generation of COCs. In general, direct comparisons of effects of different types of COCs on haemostatic variables are available for only a very few factors, which hampers the drawing of general conclusions with respect to haemostatic consequences.

Standardization of Measurement of Components of the Fibrinolytic System - Introduction and Current Status

There is compelling evidence that measurement of analytes of the fibrinolytic system may be helpful for the clinician in a number of situations. Except for measurement of plasma fibrin d-dimer such quantities have not been widespread introduced in the clinical laboratory. One main reason for this is a documented large method and interlaboratory variation for specific analytes. This manuscript describes historical aspects and the current status of standardization with respect to measurement of fibrinolytic quantities. Also, it describes recent initiatives taken within the framework of International Society of Thrombosis and Haemostasis (ISTH) and the International Federation of Clinical Chemistry (IFCC) to promote standardization within the field of fibrinolysis (and coagulation).

Common paraoxonase gene variants, mortality risk and fatal cardiovascular events in elderly subjects

Recent studies indicate that the enzyme paraoxonase may be an important modulator of cardiovascular disease risk because of its ability to protect LDL from oxidation. We tested for association between two functional variants of the paraoxonase gene (Met-55/Leu and Gln-192/Arg) and both all-cause mortality and fatal cardiovascular disease. This was done within a population-based study among subjects aged 85 years and over in a cross-sectional and a prospective design. In the cross-sectional analysis, the distribution of both paraoxonase genotypes was found to be similar in the subset of 364 elderly subjects who were born in Leiden, The Netherlands, as compared with 250 young subjects whose families originated from the same geographical region. The polymorphisms were in strong linkage disequilibrium (P<0.00001) and the frequency of the haplotype carrying both risk alleles was not lower in the elderly than in the young (0.313 vs. 0.284). The complete cohort of 666 elderly subjects was followed over 10 years. The risk of all-cause and cardiovascular mortality was not increased in elderly subjects with the paraoxonase Leu/Leu (RR, 1.1 [95% CI, 0.9-1.5] and 1.3 [95% CI, 0.8-2.0], respectively) or the Arg/Arg genotype (RR, 0. 9 [95% CI, 0.7-1.2] and 0.7 [95% CI, 0.4-1.3], respectively). In a subset of patients with diabetes, the all-cause mortality risk was elevated in Arg/Arg carriers (RR, 2.1 [95% CI, 0.8-5.8]) but this did not reach statistical significance. Analysis of genotype combinations did not yield significant associations with mortality. The paraoxonase gene variants, previously associated with coronary artery disease, are thus not likely to have a major effect on the risk of fatal cardiovascular disease in the population at large. Adverse effects of the gene variants might be observed in subjects exposed to factors that enhance oxidative stress such as diabetes.

Different Effects of Lipopolysaccharide on Plasminogen Activator Inhibitor-1 Production in Aortic Media in Vivo and in Culture

Background: Lipopolysaccharide (endotoxin) has been shown to increase the expression of plasminogen activator inhibitor type-1 (PAI-1) in the vessel wall. Endotoxin is known to increase PAI-1 production in endothelial cells, but its action on smooth muscle cells (SMCs) is presently not clear. In this study we determined the effect of endotoxin on PAI-1 and tissue plasminogen activator (t-PA) production by aortic SMCs in vivo in two animal species, and in culture. Methods: The aortas of Sprague Dawley rats and of New Zealand White rabbits were rapidly excised after parenteral administration of endotoxin. Total RNA was extracted from the aortic media, and PAI-1 and t-PA mRNA levels were quantified after Northern blotting. In addition, cultured rat aortic SMCs were treated with endotoxin. PAI activity in the conditioned medium was determined with a spectrophotometric assay, and total RNA was extracted from the cells and analyzed. Results: A rapid and strong induction in the aortic medi a of PAI-1 mRNA was observed by endotoxin in both rat (50 mg/kg) and rabbit (1 mg/kg). t-PA mRNA was barely detectable and was not increased by endotoxin. Studies in cultured SMCs showed low expression of PAI-1 mRNA under serum-free conditions and little PAI activity in the cell-conditioned medium. Endotoxin did not increase the levels of PAI-1 mRNA nor PAI activity under serum-free conditions. The effect of endotoxin (10 mg/ml) in the presence of 10% (v/v) newborn calf serum on PAI-1 mRNA was negligible; PAI activity, however, increased by 50.3 +/- 7.3% compared with controls. mRNA levels of t-PA and low-density lipoprotein/receptor-related protein/alpha2-macroglobulin receptor also increased after endotoxin administration. PAI activity was identified as PAI-1 by immunoblotting. Fibrin zymography showed that t-PA was present only in complex with PAI-1. Conclusions: A strong increase in PAI-1 gene expression by endotoxin was observed in aortic SMCs in vivo but not in culture. Th is suggests that the effect of endotoxin on SMCs is indirect. The fibrinolytic/proteolytic potential of the SMCs in the vessel wall is likely to have important implications for the migration of cells during vessel wall remodeling, such as neointima formation, during tumor cell metastasis, and for the fate of intramural thrombi.

Both raloxifene and estrogen reduce major cardiovascular risk factors in healthy postmenopausal women: A 2-year, placebo-controlled study

Currently raloxifene, a selective estrogen receptor modulator, is being investigated as a potential alternative for postmenopausal hormone replacement to prevent osteoporosis and cardiovascular disease. We compared the 2-year effects of raloxifene on a wide range of cardiovascular risk factors with those of placebo and conjugated equine estrogens (CEEs). Analyses were based on 56 hysterectomized but otherwise healthy postmenopausal women aged 54. 8+/-3.5 (mean+/-SD) years who entered this double-blind study and who were randomly assigned to raloxifene hydrochloride 60 mg/d (n=15) or 150 mg/d (n=13), placebo (n=13), or CEEs 0.625 mg/d (n=15). At baseline and after 6, 12, and 24 months of treatment, we assessed serum lipids, blood pressure, glucose metabolism, C-reactive protein, and various hemostatic parameters. Compared with placebo, both raloxifene and CEEs lowered the level of low density lipoprotein cholesterol by 0.53 to 0.79 mmol/L (all P<0.04) and lowered, at 24 months, the level of fibrinogen by 0.71 to 0.86 g/L (all P<0.05). The effects of raloxifene and CEEs did not differ significantly. In contrast to raloxifene, from 6 months on CEEs increased high density lipoprotein cholesterol by 0.25 to 0.29 mmol/L and reduced plasminogen activator inhibitor-1 antigen by 30.6 to 48.6 ng/mL (all P<0.02 versus both placebo and raloxifene). CEEs transiently increased C-reactive protein by 1.0 mg/L at 6 months (P<0.05 versus placebo) and prothrombin-derived fragment F1+2 by 0. 79 nmol/L at 12 months (P<0.001 versus placebo). Finally, from 12 months on, CEEs increased triglycerides by 0.33 to 0.56 mmol/L (all P<0.05 versus both placebo and raloxifene). Our findings suggest that in healthy postmenopausal women, raloxifene and estrogen monotherapy have similar beneficial effects on low density lipoprotein cholesterol and fibrinogen levels. These treatments differ, however, in their effects on high density lipoprotein cholesterol, triglycerides, and plasminogen activator inhibitor-1 and possibly in their effects on prothrombin fragment F1+2 and C-reactive protein.

Specific determination of plasmin inhibitor activity in plasma: documentation of specificity of manual and automated procedures

Recently, a chromogenic kit for determination of plasmin inhibitor activity, Coamatic Plasmin Inhibitor, has been developed with the aim to increase specificity and to allow application to a wide range of automates. The highly sensitive plasmin substrate S-2403 is used and, to further improve specificity, a low level of plasmin and a short incubation time is utilized as well as the incorporation of methylamine to quench alpha2-macroglobulin activity. The Coamatic Plasmin Inhibitor kit has been evaluated regarding specificity and compared with six commercially available plasmin inhibitor (also denoted alpha2-antiplasmin) kits and with the manual Immediate Plasmin Inhibition Test (IPIT) method, the reference method within the framework of the European Concerted Action against Thrombosis and Disabilities. Analysis of plasmin inhibitor deficient plasma with Coamatic Plasmin Inhibitor resulted in activities below 5% for all instrument applications, whereas all other commercial kits displayed unexpectedly higher values for this plasma (16-35%). There was a good agreement between the Coamatic Plasmin Inhibitor method and the IPIT method for all tested instrument applications; slope =0.80-1.02 and r = 0.92-0.97. No interference was detected from alpha2-macroglobulin, lysine, unfractionated and low-molecular weight heparin, and epsilon-amino caproic acid or from the non-plasminogen binding form of plasmin inhibitor.

Postprandial response of activated factor VII in elderly women depends on the R353Q polymorphism

BACKGROUND

Activated factor VII (FVIIa) is a very potent coagulant and may be a key determinant of the outcome of a cardiovascular event. The main determinants of FVIIa are the R353Q polymorphism and dietary fat intake, which may have an interactive effect.

OBJECTIVE

The objective was to investigate whether the response of FVIIa to a fat-rich breakfast varies across genotypes of the R353Q polymorphism.

DESIGN

Ninety-one apparently healthy elderly women (>60 y of age), 56 with the RR genotype and 35 with the RQ or QQ genotype, participated in a randomized, controlled crossover study. Subjects received 5 breakfasts, each on a separate day: 1 low-fat control breakfast and 4 high-fat test breakfasts. Blood samples were taken for measurement of FVIIa at 0800 before each breakfast (fasting) and at 1300 and 1500.

RESULTS

The mean (+/-SD) fasting FVIIa concentration was 93.3 +/- 26.7 U/L in women with the RR genotype, 49.3 +/- 19.1 U/L in those with the RQ genotype and 39.5 +/- 17.2 U/L in those with the QQ genotype. The mean absolute response to all 4 test breakfasts was 37.0 U/L in those with the RR genotype and 16. 1 U/L in those carrying the Q allele (P < 0.001 for difference). Likewise, the FVIIa response relative to fasting FVIIa was significantly higher in women homozygous for the R allele.

CONCLUSION

This observation may indicate a considerable difference in cardiovascular risk between genotype groups as a result of an increase in FVIIa after a fat-rich diet.

Angiotensin I-converting enzyme and plasminogen activator inhibitor-1 gene variants: risk of mortality and fatal cardiovascular disease in an elderly population-based cohort

OBJECTIVES

We studied the contribution of putative risk genotypes at the angiotensin I-converting enzyme inhibitor (ACE D/D) and plasminogen activator inhibitor-1 (PAI-1 4G/4G) loci to all-cause and cardiovascular mortality in a population-based cohort.

BACKGROUND

The ACE D/D and PAI-1 4G/4G genotypes have been consistently associated with elevated plasma activities of the gene products. Their role in cardiovascular disease, although explored intensively, is still equivocal.

METHODS

The ACE and PAI-1 genotypes were determined in 648 subjects > or =85 years old. In a cross-sectional analysis, the genotype distributions in a subset of 356 elderly subjects who were born in Leiden, The Netherlands, were compared with those in 250 young subjects whose families originated from the same geographic region. In addition, the complete cohort of elderly subjects was followed over 10 years for all-cause and cardiovascular mortality and was stratified according to genotype.

RESULTS

In the cross-sectional analysis, the ACE and PAI-1 genotype distributions were similar in elderly and young subjects. In the prospective follow-up study, however, the age-adjusted risk of fatal ischemic heart disease was increased threefold (95% confidence interval [CI] 1.2 to 7.6) in elderly men carrying the PAI-1 4G/4G genotype. The risk of all-cause mortality was not increased among elderly subjects carrying the PAI-1 4G/4G (relative risk [RR] 0.9, 95% CI 0.7 to 1.1) or the ACE D/D genotype (RR 0.9, 95% CI 0.7 to 1.1), nor did we observe elevated risks of death from all cardiovascular diseases combined. There was no interaction between the genotypes.

CONCLUSIONS

The PAI 4G/4G genotype may be a risk factor for fatal ischemic heart disease in elderly men. The impact of moderately increased ACE and PAI-1 activities associated with the ACE D/D and PAI-1 4G/4G genotypes is too small to affect mortality in the general population.

Importance of levonorgestrel dose in oral contraceptives for effects on coagulation

Combined oral contraceptives show clear differences in effect on the tissue factor-initiated coagulation test of activated protein C resistance, which is dependent on the presence and dosage of levonorgestrel. Multiphasic levonorgestrol oral contraceptives differ from monophasic contraceptives and resemble third-generation contraceptives.

Plasma homocysteine is weakly correlated with plasma endothelin and von Willebrand factor but not with endothelium-dependent vasodilatation in healthy postmenopausal women

BACKGROUND

Hyperhomocysteinemia is an independent cardiovascular risk factor, possibly through the induction of endothelial dysfunction. The postmenopausal state is associated with increased plasma homocysteine. We examined whether increased homocysteine is associated with impaired endothelial function.

METHODS

Sixty-three hysterectomized but otherwise healthy postmenopausal women (54.8 +/- 3.5 years) participated in this study. Fasting total plasma homocysteine (tHcy) was measured as free plus protein-bound homocysteine. Endothelial function was assessed by measuring plasma concentrations of the endothelium-derived proteins endothelin (ET), von Willebrand factor (vWF), and plasminogen activator inhibitor type 1 (PAI-1) as well as brachial artery flow-mediated, endothelium-dependent vasodilatation (FMD).

RESULTS

Plasma tHcy was 9.6 +/- 2.5 micromol/L. After adjustment for possible confounders, a 1 micromol/L increase in tHcy was associated with an increase in ET of 0.08 ng/L (P = 0.045) and an increase in vWF of 4.2% (P = 0.05). No statistically significant association was present between tHcy and PAI-1 or FMD.

CONCLUSIONS

Increased fasting homocysteine in postmenopausal women may impair some aspects of endothelial function. It is of clinical interest to study whether homocysteine lowering can improve endothelial function and thus cardiovascular morbidity and mortality in postmenopausal women.

Plasma Homocysteine Is Weakly Correlated with Plasma Endothelin and von Willebrand Factor but not with Endothelium-dependent Vasodilatation in Healthy Postmenopausal Women

Background: Hyperhomocysteinemia is an independent cardiovascular risk factor, possibly through the induction of endothelial dysfunction. The postmenopausal state is associated with increased plasma homocysteine. We examined whether increased homocysteine is associated with impaired endothelial function.

Methods: Sixty-three hysterectomized but otherwise healthy postmenopausal women (54.8 ± 3.5 years) participated in this study. Fasting total plasma homocysteine (tHcy) was measured as free plus protein-bound homocysteine. Endothelial function was assessed by measuring plasma concentrations of the endothelium-derived proteins endothelin (ET), von Willebrand factor (vWF), and plasminogen activator inhibitor type 1 (PAI-1) as well as brachial artery flow-mediated, endothelium-dependent vasodilatation (FMD).

Results: Plasma tHcy was 9.6 ± 2.5 μmol/L. After adjustment for possible confounders, a 1 μmol/L increase in tHcy was associated with an increase in ET of 0.08 ng/L (P = 0.045) and an increase in vWF of 4.2% (P = 0.05). No statistically significant association was present between tHcy and PAI-1 or FMD.

Conclusions: Increased fasting homocysteine in postmenopausal women may impair some aspects of endothelial function. It is of clinical interest to study whether homocysteine lowering can improve endothelial function and thus cardiovascular morbidity and mortality in postmenopausal women.

Increased thromboxane biosynthesis is associated with poststroke dementia

BACKGROUND AND PURPOSE

It has been suggested that daily intake of aspirin is associated with a reduction of cognitive decline, both in normal and in demented subjects, but the mechanism is unclear. We have therefore studied the relationship between thromboxane (TX) A(2) biosynthesis, as reflected by the urinary excretion of 11-dehydro-TXB(2), and the presence of dementia in patients after acute stroke.

METHODS

Patients from the Rotterdam Stroke Databank were screened for dementia between 3 and 9 months after stroke. Patients had a full neurological examination, neuropsychological screening, and, if indicated, extensive neuropsychological examination. Criteria used for the diagnosis of dementia were from the Diagnostic and Statistical Manual of Mental Disorders, Third Edition (Revised). Urine samples were taken at the time of screening. Urinary 11-dehydro-TXB(2) was measured by means of a previously validated radioimmunoassay.

RESULTS

Dementia was diagnosed in 71 patients, and urine samples were available for 62. Median value (range) of 11-dehydro-TXB(2) was 399 (89 to 2105) pmol/mmol creatinine for demented patients versus 273 (80 to 1957) for 69 controls with stroke but without dementia (P=0.013). No difference was found between 44 patients with vascular dementia, 404 (89 to 2105) pmol/mmol creatinine, and 18 patients with Alzheimer's disease plus cerebrovascular disease, 399 (96 to 1467) pmol/mmol creatinine (P=0.68). In a stepwise logistic regression analysis, in which possible confounders such as use of antiplatelet medication, cardiovascular risk factors, and type of stroke were taken into account, increased urinary excretion of 11-dehydro-TXB(2) remained independently related to the presence of dementia (OR 1.12, 95% CI 1.03 to 1.22 per 100 pmol/mmol creatinine). The difference in metabolite excretion rates between demented and nondemented patients was most prominent within the subgroup of ischemic stroke patients who received aspirin (P<0.01).

CONCLUSIONS

Increased thromboxane biosynthesis in the chronic phase after stroke is associated with the presence of but not the type of poststroke dementia. It is particularly apparent in patients on aspirin, thereby suggesting the involvement of extraplatelet sources of TXA(2) production in this setting.

DNA-polymorphisms and plasma levels of vascular disease risk factors in Greenland Inuit--is there a relation with the low risk of cardiovascular disease in the Inuit?

Greenland Inuit are a population with a low risk of cardiovascular disease. Recently, we stated that frequencies of potentially high risk alleles of the apolipoproteins, fibrinogen, factor V, glycoprotein IIIa and factor VII (FVII) genes have different allele frequencies in the Inuit when compared with Caucasian populations. We have extended this study and evaluated whether or not this was also true for the genetic polymorphisms of tissue-type plasminogen activator (t-PA), plasminogen activator inhibitor-1 (PAI-1), angiotensin-converting enzyme (ACE) and angiotensinogen in a group of 133 Greenland Inuit, aged 30-34 gamma. In addition, we compared the plasma levels of these factors and those of C-reactive protein (CRP) and D-Dimer in Inuit and in Danes, comparable for age and gender. Frequencies (f) were assessed of the alleles that are known as the potential high risk alleles in Caucasians. In the Inuit, the f(insertion allele) of the t-PA intron8ins311 polymorphism was 0.37 (CI 0.32-0.43), the f(4G allele) of the PAI-1 promoter polymorphism was 0.88 (CI 0.83-0.91), the f(deletion allele) of the ACE intron16ins287 polymorphism was 0.40 (CI 0.33-0.47) and the f(M-allele) of the angiotensinogen M/T353 polymorphism was 0.30(CI 0.25-0.38). As for fibrinogen and FVII polymorphisms, these frequencies are all significantly different from what is reported for Caucasian populations. In the Inuit, plasma levels of fibrinogen and D-Dimer were higher than in the Danes, the PAI-1 levels were lower and FVII, t-PA and CRP levels were comparable. The observed allele frequencies of the polymorphisms of t-PA, fibrinogen, FVII, ACE, angiotensinogen and the plasma levels of PAI-1 and D-Dimer were in accordance with the low CVD risk in the Inuit, considering the observed associations between these measures and CVD risk in Caucasian populations, but for other measures this was not the case (allele frequencies of the PAI-1 polymorphism, and plasma levels of fibrinogen, FVII and t-PA). In conclusion there are clear differences in genetic background and plasma levels of risk factors in Greenland Inuit compared with Caucasian populations, and these differences were sometimes, but not always, in accordance with the observed low cardiovascular disease risk of the Inuit population.

Inflammatory status as a main determinant of outcome in patients with unstable angina, independent of coagulation activation and endothelial cell function

AIMS

Inflammation, endothelial cell function and the coagulation system have been demonstrated to be involved in the onset and course of unstable angina. Whether a proinflammatory state independently determines outcome is unknown and has not been determined yet in a clinically well defined study population of consecutive patients admitted with unstable angina.

METHODS AND RESULTS

Markers of inflammation, coagulation activation and endothelial cell function were determined on admission in blood of 211 consecutive patients with severe unstable angina and were related to the in-hospital course. Refractory unstable angina occurred in 76 patients (36%) during their hospital stay. In a univariate analysis, C-reactive protein (P = 0.03), fibrinogen (P < 0.001) and erythrocyte sedimentation rate (P = 0.001) levels were significantly higher in patients with refractory unstable angina, when compared with patients who had an uneventful clinical course. The odds ratios (95% CI) adjusted for age, sex, body mass index, smoking behaviour and cholesterol levels of the occurrence of refractory unstable angina for patients in the highest quartile compared with patients in the lowest quartile of inflammatory markers were 2.19 (0.94-5.11) for C-reactive protein, 2.83 (1.13-7.10) for fibrinogen and 4.72 (1.70-13.09) for the erythrocyte sedimentation rate. The findings were not affected by the presence or absence of myocardial necrosis or the interval between onset of angina and blood collection. No association was found between markers of coagulation activation or markers of endothelial cell function, and in-hospital outcome.

CONCLUSION

We found that in a clinically well-defined study population of patients with severe unstable angina, a proinflammatory state is an important and independent determinant of short-term outcome. The data strengthen the importance of inflammation in this syndrome.

Effect of the stromelysin-1 promoter on efficacy of pravastatin in coronary atherosclerosis and restenosis

It has proved difficult to identify high-risk patients for atherosclerosis and to determine how they might respond to medication. Recently, a common promoter variant of the human stromelysin-1 gene has been reported, which has been shown to affect the transcription. We investigated whether this polymorphism had any impact on the risk of events, especially restenosis and progression of coronary artery disease and whether the effect was modulated by treatment with pravastatin. The stromelysin-1 genotype was determined for 496 men with coronary artery disease and cholesterol levels between 4.0 and 8.0 mmol/L, participating in the Regression Growth Evaluation Statin Study (REGRESS) study, a clinical trial assessing the effect of the lipid-lowering drug pravastatin on the progression of atherosclerosis. Patients in the placebo group with 5A6A or 6A6A genotypes had more clinical events than patients with the 5A5A genotype (26% and 12%, respectively, p = 0.03). In the pravastatin group, the risk of clinical events in patients with 5A6A or 6A6A genotypes was lower, compared with placebo, whereas it was unchanged in those with a 5A5A genotype (p value for interaction: 0.038). Also, the incidence of repeat angioplasty in the placebo group was greater in patients with the 6A6A or 5A6A genotypes, compared with 5A homozygotes (38% and 40%, respectively, vs 11%, p = 0.09). Again, treatment substantially reduced the incidence in heterozygotes and 6A homozygotes (0% and 15%, respectively), whereas it was unchanged in 5A homozygotes (28%, p for interaction: 0.002). These effects were independent of the effects of pravastatin on the lipid levels. Thus, this study suggests that the stomelysin-1 promoter polymorphism confers a genotype-specific response to medication in determining clinical event-free survival and the risk for symptom-driven repeat angioplasty. This variant may therefore act as a predictor, not only of disease progression, but also of response to therapy and risk of restenosis.

The oral bioavailability of pentosan polysulphate sodium in healthy volunteers

OBJECTIVE

Pentosan polysulphate sodium (PPS), a heparin-like drug, is supposed to be orally applicable. The objective of the present study was to assess the oral bioavailability of PPS. However, since specific assays for PPS do not exist, this was done by using primary and secondary effect parameters.

METHODS

The study was carried out using a three-way randomized crossover design with 18 healthy young male volunteers. The subjects received three treatments: PPS i.v. (50 mg), PPS orally (1500 mg) and placebo (orally). Blood sampling was done for activated partial thromboplastin time (APTT), anti-Xa activity, hepatic triglyceride lipase, lipoprotein lipase, tissue plasminogen activator (t-PA) activity, fibrin plate lysis, total triglyceride, total cholesterol, HDL and LDL.

RESULTS

Intravenously administered PPS significantly increased APTT, anti-Xa activity, hepatic triglyceride lipase and lipoprotein lipase compared with placebo in a magnitude comparable to other i.v. heparin-like compounds. Orally administered PPS did not significantly influence any of the parameters when compared with placebo. Point estimates for the oral bioavailability of PPS were in the range of 0% with small confidence intervals (CIs).

CONCLUSION

The oral bioavailability of PPS is negligible in young healthy males.

Fibrinolytic activity in peripheral atherosclerosis in the elderly

Increased concentrations of plasminogen activator inhibitor type 1 (PAI-1) and of D-dimer have jointly been found in subjects with cardiovascular disease. To understand this apparent paradox of increased inhibition of fibrinolysis (high PAI-1) combined with increased fibrinolytic activity (high D-dimer), we examined the relation between D-dimer, PAI-1 and the activator of fibrinolysis, tissue type plasminogen activator (t-PA) in subjects with varying severity of peripheral atherosclerosis. In 325 subjects selected from the Rotterdam Study, a cohort of 7983 men and women aged 55 years and over, the ankle to brachial systolic blood pressure ratio, t-PA antigen and activity, PAI-1 antigen and D-dimer were measured. T-PA antigen and t-PA activity were, independent from each other, increased with degree of atherosclerosis; t-PA antigen increased with 3.5 ng/ml (SE 1.7, p = 0.04) and t-PA activity with 0.46 IU/ml (0.20, p = 0.02) per unit decrease in ankle to brachial pressure ratio (i.e. increase in atherosclerosis). PAI-1 antigen was not related to atherosclerosis. More marked atherosclerosis was associated with increased D-dimer, mainly in subgroups with PAI-1 antigen below 50 ng/ml, t-PA antigen below 10 ng/ml, or t-PA activity above 1.5 IU/ml. In contrast to current beliefs, we found that only a fraction of the variation of t-PA antigen was due to the variation in circulating PAI-1 antigen. A slight positive association was observed between t-PA antigen and D-dimer. PAI-1 and t-PA activity were not associated with D-dimer concentration. In conclusion, in subjects with peripheral atherosclerosis PAI-1 antigen is not increased, but low PAI-1 levels (and possibly also low levels of t-PA antigen and high levels of t-PA activity) appear to be required to increase circulating D-dimer. This suggests that increased D-dimer levels in subjects with atherosclerosis do not reflect increased inhibition, but rather reflect increased fibrinolysis.

Mortality risk in men is associated with a common mutation in the methylene-tetrahydrofolate reductase gene (MTHFR)

An elevated level of homocysteine in plasma is associated with the occurrence of cardiovascular disease. A common ala-to-val mutation in the methylenetetrahydrofolate reductase gene (MTHFR) is associated with an elevated level of plasma homocysteine. We studied the possible detrimental effects of the MTHFR mutation on mortality. Within a population-based study in the city of Leiden, the Netherlands, we first compared the MTHFR genotype distribution among 365 elderly subjects aged 85 years and over born in Leiden, and 250 young subjects aged 18 to 40 years whose families originated from the same geographical region. Second, the complete cohort of 666 subjects aged 85 years and over was followed over a period of 10 years for all-cause and cause-specific mortality and stratified according to MTHFR genotype. The frequency of the MTHFR mutation was significantly lower in the elderly than in the young (0.30 and 0.36, respectively; P = 0.03). The difference in genotype distribution was only present in men. The estimated mortality risk up to 85 years in men carrying the vallval genotype was 3.7 (95% confidence interval (CI), 1.3-10.9). Over the age of 85, mortality in men with the vallval genotype was increased 2.0-fold (95% CI, 1.1-3.9) and appeared to be attributable to cancer rather than cardiovascular causes of death. Among women aged 85 years and over, no deleterious effect of the MTHFR mutation was observed. In conclusion, the MTHFR mutation is associated with increased mortality in men in middle and old age, but not in women.

Normalized activated protein C ratio itself not associated with increased risk of venous thromboembolism

Recently, discussions focused on the question whether acquired activated (APC) resistance is a clue to the observed association between venous thromboembolism (VTE) risk and oral contraceptive (OC) use, especially with the so-called third-generation OC. The objective of our study was to check the validity of acquired APC resistance regarding VTE risk in a case-control study. Sixty-seven women with confirmed VTE diagnosis (n = 67) were consecutively ascertained in primary health care settings, interviewed and blood samples taken (at the earliest 6 months after VTE). Cases were age-matched to 290 population controls. Acquired APC resistance was measured as normalized APC ratio (APCRN). The effect of APC on tissue factor initiated thrombin generation was measured in plasma using alpha 2-macroglobulin attached thrombin activity as an endpoint. Higher risk (odds) ratio with 95% CI) of VTE for carriers of heterozygote Factor V Leiden mutation was confirmed [OR = 2.72 (CI:1.51-4.92)]. However, there is no association between VTE and the level of APCRN OR 0.65 (CI:0.35-1.22). We conclude that acquired APC resistance, measured with a tissue factor initiated test, is unlikely to have a direct association to the clinical outcome of venous thromboembolism.

Genetic modulation of coagulation factor VII plasma levels: contribution of different polymorphisms and gender-related effects

We studied the relationships among different polymorphisms of FVII gene in determining FVII levels, in a sample of 335 male and female Italian volunteers. The hypervariable region 4 (HVR4), the promoter decanucleotide insertion (-323 0/10 bp) and the R353Q polymorphisms of FVII gene were evaluated. The association of HVR4 or -323 0/10 bp polymorphism with plasma FVII levels differed between gender (Interaction term: p = 0.02 and p = 0.03, respectively), showing stronger effect in males than in females. In males, the R353Q and the HVR4 polymorphisms showed an incremental influence on FVII variance (F = 8.9, p <0.001 and F = 4.4, p = 0.01, respectively). Moreover, the effects of Q and 10 bp alleles on the reduction of FVII activity levels were significantly potentiated by the presence of H7 allele of HVR4 (Interaction term p = 0.03 for R353Q*HVR4 and p = 0.03 for -323 0/10 bp*HVR4). In conclusion, the effect of FVII polymorphisms on FVII levels was gender dependent and derived from a complex interaction among them. The HVR4 polymorphism seems to add an independent, albeit small, contribution to the regulation of FVII plasma levels.

The CAMCOG: a useful screening instrument for dementia in stroke patients

BACKGROUND AND PURPOSE

Most mental screening tests focus on the detection of cognitive deficits compatible with Alzheimer's disease. Stroke patients who develop a dementia syndrome, however, constitute a more heterogeneous group with both cortical and subcortical disturbances. We assessed the diagnostic accuracy of the CAMCOG (the cognitive and self-contained part of the Cambridge Examination for Mental Disorders of the Elderly) and the Mini-Mental State Examination (MMSE) for dementia in patients with a recent stroke.

METHODS

In patients aged 55 and older who were admitted in the Rotterdam Stroke Databank, cognitive functioning was assessed between 3 and 9 months after the most recent stroke. The "gold standard" diagnosis of dementia was compatible with the criteria of the Diagnostic and Statistical Manual of Mental Disorders, Third Edition, Revised. The CAMCOG and MMSE scores were obtained independent of the diagnostic procedure.

RESULTS

Of 300 consecutive patients, 71 (23.7%) were demented. Sixteen severely demented patients could not be tested and were excluded. The CAMCOG and MMSE scores were significantly related to dementia (both P<0.0001) in a logistic regression model. Receiver operating characteristic analysis showed that the CAMCOG was a more accurate screening instrument (area under the curve for CAMCOG, 0.95; for MMSE, 0.90). Two other clinical variables independently improved the diagnostic accuracy of the MMSE and CAMCOG: patients with a left hemispheric lesion had a lower (odds ratio, 0.3; 95% confidence interval, 0.1 to 0.7), and patients with hemorrhagic stroke had a greater chance of being demented (odds ratio, 3; 95% confidence interval, 1 to 10). The effect of left hemispheric lesion as an independent diagnostic factor could not be explained by selection or its association with aphasia alone.

CONCLUSIONS

The CAMCOG is a feasible instrument for use in patients with a recent transient ischemic attack or stroke. It is a more accurate screening tool for dementia than the MMSE, especially when type and site of stroke are taken into account.

The risk of mortality and the factor V Leiden mutation in a population-based cohort

The factor V Leiden mutation (conferring resistance to activated protein C) has been implicated in the risk of arterial thrombosis and is a well-established risk factor for venous thrombosis especially in the elderly. We studied whether the disease association of the factor V mutation is reflected in an increased all-cause and cause-specific mortality. First, the prevalence of the factor V Leiden mutation was determined in a population-based study among subjects aged 85 years and over (4.7%, n = 660) and was found to correspond to the prevalence in young subjects aged 18 to 40 years (5.0%, n = 321). Secondly, we studied the association of factor V Leiden with the risk of all-cause mortality and specific causes of death in the elderly cohort during a 10-year follow-up period. Neither the all-cause mortality risk (RR 1.0; 95% CI, 0.7-1.5), nor the risk of death due to cardiovascular disease (RR 0.9; 95% CI, 0.5-1.7) were increased in elderly subjects heterozygous for factor V Leiden. Our study thus indicates that heterozygosity for factor V Leiden does not affect population mortality.

EUROPA substudies, confirmation of pathophysiological concepts. European trial on reduction of cardiac events with perindopril in stable coronary artery disease

In patients with coronary disease, ACE inhibitors may improve endothelial function in the coronary arteries as well as peripheral arteries, and may have anti-proliferative effects which might result in retardation of progression of coronary artery disease. In order to verify these pathophysiological concepts, a series of substudies will be conducted as part of the EUROPA programme. Angiographic and intravascular ultrasound examination of coronary arteries will be performed in approximately 400 patients before and after 3 years' treatment with either perindopril or placebo, in order to assess progression and possible regression of coronary lesions. B-mode ultrasonography of the brachial artery will be used as a model for changes in the coronary arteries, to assess endothelial function in response to ischaemia (reactive hyperaemia) and to vasoconstriction (cold pressor test). Three hundred patients will be investigated before and at different intervals after initiation of study treatment. In addition genetic characterization will be performed of patients participating in EUROPA in order to assess whether specific genotypes do respond more or less favourably to perindopril. In addition, the effect of perindopril will be investigated in patients with diabetes type II, since ACE inhibition in such patients may improve microvascular function and renal function. Integration of these substudies, as well as detailed analysis of other specific subgroups in EUROPA, will help us understand the effects of treatment with perindopril in patients with stable coronary artery disease.

Dietary effects on coagulation factor VII vary across genotypes of the R/Q353 polymorphism in elderly people

The objective of this study was to evaluate the association of factor VII with dietary factors while also considering the R/Q353 polymorphism. Nutrition is an important determinant of coagulation factor VII, which is also genetically determined by the R/Q353 polymorphism. High levels of coagulation factor VII clotting activity (FVII:C) are associated with the risk of myocardial infarction; nutrition may have an effect on these levels if people are genetically susceptible to dietary changes. FVII:C was measured in 3005 elderly subjects, and the extreme quintiles of the FVII:C distribution were selected for measurement of the R/Q353 genotype and FVII:Chr (reflects total factor VII). In these 1158 subjects, habitual diet was assessed with a semiquantitative food-frequency questionnaire. The frequency of the Q353 allele was 0.24 in the lowest and 0.09 in the highest quintile. The quintiles were combined for linear regression analyses. FVII:C was inversely associated with fiber [beta = -0.64 %pooled plasma (PP)/g, confidence interval (CI): -1.07,-0.21] and protein intake (beta = -0.16 %PP/g, CI: -0.31,-0. 01) and positively with saturated fat intake (beta = 0.19 %PP/g, CI: -0.10,0.48). FVII:Chr was inversely associated with fiber (beta = -0. 38 %PP/g, CI: -0.71,-0.05). No other associations with diet were observed. The inverse association of FVII:C with fiber was stronger in subjects with the RR genotype (beta = -0.76 %PP/g, CI: -1.23,-0. 29), than in those with the RQ/QQ genotypes (beta = -0.19 %PP/g, CI: -0.97,0.59). The same was found for FVII:Chr. The association of FVII:C with saturated fat was positive in those with the RR allele and inverse in those carrying the Q allele. These findings suggest that the strength of the association between coagulation factor VII and diet varies across the genotypes of the R/Q353 polymorphism.

Response to activated protein C in subjects with and without dementia. The Dutch Vascular Factors in Dementia Study

We performed a cross-sectional case-control study among 295 subjects with dementia and 406 control subjects drawn from participants of the Rotterdam Study, a population-based cohort study among subjects aged 55 years or over, and from participants of the Rotterdam Stroke Databank, a hospital-based stroke registry, to evaluate the association of the factor V Leiden mutation and activated protein C (APC) response with dementia and its subtypes. The risk of dementia was 2.11-fold increased among carriers of factor V Leiden mutation relative to subjects lacking factor V Leiden mutation (95% confidence interval, CI, 0.93-4.77). The increased risks of vascular dementia and of Alzheimer's disease were 4.28 (95% CI 1.26-14.5) and 2.15 (95% CI 0.82-5.63), respectively. No association was found for APC response. We showed a nonsignificant twofold increased risk of dementia among subjects with factor V Leiden. The association appeared to be stronger for vascular dementia.

[Clinical presentation of unstable angina may influence the formation of thrombin during spontaneous episodes of ischemia]

In order to evaluate whether different clinical presentations of unstable angina are associated with a different degree or pattern of activation of the hemostatic, fibrinolytic and inflammatory systems, we measured plasma levels of thrombin-antithrombin III, plasmin-alpha2- antiplasmin complexes and C-reactive protein, as markers of activation of coagulation, fibrinolysis and inflammation respectively, in two groups of patients: 7 patients with de novo unstable angina (Group 1) and 7 patients with destabilizing unstable angina (Group 2). Blood samples were taken on admission for measuring levels of C-reactive protein and during ischemic episodes at the onset of ECG changes and pain (0 min) and after 5, 15 and 60 min in order to assess the peak values of thrombin-antithrombin III and plasmin-alpha2-antiplasmin during the episode. Thrombin-antithrombin III levels in Group 1 were 1.8 microgram/l (0.3-4.15) at 0 min and increased to 17 micrograms/l (2.8-60) after 5 to 15 min (p = 0.013); conversely thrombin-antithrombin III levels in Group 2 were 2.15 microgram/l (1.4-3.8) at 0 min and raised to 4 micrograms/l (2-43) after 5 to 15 min (NS). No significant differences in both groups were observed in plasmin-alpha2-antiplasmin levels (Group 1:650 micrograms/l, ranged 492-956, at 0 min vs 670 microgram/l, range 415-977, at peak; Group 2: 480 micrograms/l, range 274-955, at 0 min vs 502 micrograms/l, range 304-1027, at peak; NS). Inversely, C-reactive protein levels on admission were 4 mg/dl (range 2-27) in Group 1, and 1 mg/dl (range 0.6-4) in Group 2 (p = 0.006). In conclusion, patients with de novo unstable angina have significantly enhanced thrombin (but not plasmin) production during spontaneous ischemic episodes than patients with destabilizing unstable angina. Furthermore, patients with de novo unstable angina have enhanced acute phase responses than patients with destabilizing unstable angina. Our data suggest that different pathogenetic mechanisms may be responsible for acute ischemic episodes in unstable angina and may explain different response to antithrombotic therapy in unstable angina patients.