Sex Difference in the Effect of ACE-DD Genotype on the Risk of Premature Myocardial Infarction

In this association study the authors compared the insertion/deletion (I/D) angiotensin-I converting enzyme (ACE) gene polymorphism in females and males with premature myocardial infarction (MI). I/D ACE gene polymorphism was tested in 738 subjects: 302 patients with MI (151 men and 151 women) and 436 healthy subjects (207 men and 229 women). In women the ACE-DD genotype was not associated with MI (OR 1.1, 95% CI 0.6-2.1, p=0.6), whereas the ACE-DD genotype conferred a 2-fold independent risk for MI in men (95% CI=1.2-3.4; p=0.013) after adjustment for cardiovascular risk factors. The authors found evidence for the sex difference in the effect of the ACE-DD genotype on MI risk. The ACE-DD genotype conferred a 2-fold independent risk for premature MI in males.

The effect of various menopausal hormone therapies on markers of inflammation, coagulation, fibrinolysis, lipids, and lipoproteins in healthy postmenopausal women

OBJECTIVE

Androgenic progestins such as norethisterone acetate (NETA) may influence the effect of estradiol (E(2)) therapy. We compared the influence of oral E(2), with and without NETA, and transdermal E(2) on markers of coagulation, fibrinolysis, and inflammation and on lipids and lipoproteins in healthy postmenopausal women.

DESIGN

A total of 112 healthy postmenopausal women were randomized to receive treatment with either oral E(2), with or without NETA, transdermal E(2), or placebo. At baseline and after 28 weeks, levels of serum lipids and lipoproteins and markers of coagulation, fibrinolysis, and inflammation were determined.

RESULTS

Of the fibrinolytic parameters, oral E(2) (P < 0.05) and E(2) with NETA (P < 0.01) shortened euglobulin clot lysis time. Oral E(2) decreased plasminogen activator inhibitor-1 activity (P < 0.05). Oral E(2) with NETA reduced plasminogen activator inhibitor-1 antigen levels (P < 0.01) and increased D-dimer antigen levels (P < 0.001). All three modes of menopausal hormone therapy reduced tissue type plasminogen activator antigen. Of the coagulation parameters, both routes of E(2) therapy decreased fibrinogen levels (P = 0.002 for oral and P = 0.007 for transdermal E(2)), whereas E(2) with NETA showed no effect. The decrease of fibrinogen was larger after oral E(2) (P = 0.02). Oral E(2) with NETA reduced antithrombin III (P < 0.001) and protein C (P < 0.001) activity. Oral E(2) (P = 0.04) and E(2) with NETA (P < 0.01) increased C-reactive protein (CRP). Transdermal E(2) showed no influence on CRP. The addition of NETA influenced the change in CRP, as the increase in CRP was more pronounced after E(2) without NETA (P = 0.005). The levels of serum amyloid A, interleukin-6, and tumor necrosis factor-alpha did not change significantly after any of the modes of hormone therapy. Of the lipids and lipoproteins, oral E2 decreased low-density lipoprotein cholesterol (P < 0.01), lipoprotein (a) (P < 0.05), and increased high-density lipoprotein cholesterol (P < 0.05). Transdermal E(2) decreased triglycerides (P < 0.02) and increased high-density lipoprotein cholesterol (P < 0.03). Oral E(2) with NETA decreased total cholesterol (P < 0.01) and high-density lipoprotein cholesterol (P < 0.005).

CONCLUSIONS

Oral E(2), with or without NETA, produced no net activation of coagulation but improved fibrinolysis. Both modes of oral menopausal hormone therapy have a greater impact on markers of inflammation, coagulation, fibrinolysis, lipids, and lipoproteins than transdermal E(2). NETA attenuates some E(2) effects. Further studies are needed to elucidate the impact of these effects on clinical endpoints.

Determination of amputation level in ischaemic limbs using tcPO2 measurement

Background: Determination of the optimal amputation level is essential for patients, morbidity and rehabilitation. Various non-invasive procedures have been proposed to determine the optimal level of amputation. There is no consensus on the minimal tcPO2 level that is required to predict the healing of the stump. Therefore we aimed to rank the probability of primary wound healing at the most distal level and to answer the question if there is a lower limit of tcPO2 below which healing cannot occur. Patients and methods: 56 consecutive patients undergoing amputation below the knee for ischaemic gangrene of limbs were prospectively enrolled in the study. 39 were men (18 of whom were diabetics) and 17 women (8 diabetics) whose ages ranged from 45 to 87 years (mean 73 years). The total of 71 amputations was performed on the 56 patients: 39 below-knee with primary healing and, in 16 patients the above-knee reamputation was performed, due to the non-healing wound on the below-knee stump. The level of the amputation (below or above the knee) was in all cases decided solely on clinical grounds. TcPO2 was measured on each patient prior to amputation, on the dorsum of the foot and 10 cm below the knee. Results: The median tcPO2 value on the dorsum of the foot of diseased legs before amputation was 12 mm Hg (range from 0 to 22 mm Hg). At the anticipated level of the amputation of the shank, the median value of tcPO2 was 28 mm Hg (8–56 mm Hg). Patients with primary healing of postoperative wounds had significantly higher values of tcPO2 than patients with failure to heal (37mm Hg; range15–56mm Hg vs.18 mm Hg; range 8–36 mm Hg, p < 0.01). The success rate increased with higher tcPO2 values at the level of amputation. The 15% prevalence of reamputations was obtained for tcPO2 values between 25 and 36 mm Hg (median value 33 mm Hg) and the threshold value of tcPO2 below which the stump failed to heal was 15 mm Hg. Conclusions: Our study showed that tcPO2 is a reliable indicator of local ischemia. The integration of this parameter with other personal clinical criteria may be a valuable help to the surgeon in decision making.

Apolipoprotein E gene polymorphism effects triglycerides but not CAD risk in Caucasian women younger than 65 years

The pathogenesis of CAD is similar in man and woman, yet some risk factors have a greater impact on the CAD risk in woman than in man. In this study we assessed the effect of the apoE gene polymorphism on lipid metabolism and risk for CAD in women younger than 65 years (premature CAD). In a cross-sectional case-control study, 147 female Caucasian patients with premature CAD (confirmed by coronarography) were compared with a control group of 114 healthy Caucasian women. The apoE allele frequencies of patients vs. controls were 5.1% vs. 5.7% for 2, 85.4% vs. 83.3% for 3, and 9.5% vs. 11% for epsilon4. The subjects with epsilon2/3 genotype had statistically significantly higher triglycerides levels than the subjects with epsilon3/3 genotype (2.23 +/- 2.13 mmol.L(-1) vs. 1.73 +/- 0.84 mmol.L(-1); p<0.05). Logistic regression analysis revealed no association between risk genotypes (3/4 and 4/4) of the apoE gene polymorphism and CAD risk (OR 0.9; 95% CI 0. 5-1.7, P=0.7). We observed metabolic clustering of diabetes mellitus, arterial hypertension, higher BMI and triglycerides, and lower HDL cholesterol in the CAD group compared to the control group. Arterial hypertension, diabetes, HDL cholesterol level, and BMI were independent risk factors for premature CAD in female population, whereas, the risk genotype of the apoE gene polymorphism was not. In conclusion, in Slovene women risk genotypes of the apoE gene polymorphism are not associated with premature CAD; a metabolic clustering of diabetes, HDL, triglycerides and arterial hypertension is frequently present in Caucasian women with premature CAD.

Combined hormone replacement therapy improves endothelial function in healthy postmenopausal women

OBJECTIVES

Large scale epidemiological studies suggest that hormone replacement therapy (HRT) reduces cardiovascular events in postmenopausal women. Improvement in endothelial function may contribute to this protective effect.

DESIGN

In a prospective, double blind study, 61 healthy postmenopausal women were randomized to receive either oral continuous combined HRT [oestradiol 2 mg and norethisterone acetate (NETA) 1 mg per day] or placebo. Endothelial function, assessed by flow-mediated vasodilation (FMD) of the brachial artery and expression of soluble endothelial cell adhesion molecules (CAM) were determined before, after 3 and 6 months of therapy.

RESULTS

The FMD was significantly improved in women on combined HRT (from 5.97% to 10.94% after 3 months and to 10.58% after 6 months; both P < 0.01 versus baseline values) and did not change in the placebo group (6.92% at baseline, 5.86% after 3 and 6.26% after 6 months). After 3 months of combined HRT, significant decreases of 24.6% for E-selectin and 13.9% for intercellular adhesion molecule-1 (ICAM-1) were observed (both P < 0.01 versus baseline values) and were sustained after 6 months of therapy, whilst no differences emerged in the placebo group.

CONCLUSIONS

Oestradiol and norethisterone acetate improve endothelial function by both enhancing FMD and reducing the levels of soluble E-selectin and ICAM-1 in healthy postmenopausal women.

Seasonal variation of some metabolic and haemostatic risk factors in subjects with and without coronary artery disease

Acute myocardial infarction (AMI) is more frequent in winter months than in summer months. The aetiologic mechanisms underlying this seasonal pattern are poorly understood. We investigate whether seasonal variation of metabolic and haemostatic coronary risk factors exists, and whether this variation is more pronounced in subjects with coronary artery disease (CAD). In 82 subjects (47 free of clinical signs of CAD and in 35 survivors of AMI), measurements of body mass index (BMI), lipoproteins, glucose, insulin, plasminogen activator inhibitor-1, tissue-type plasminogen activator (t-PA), euglobulin clot lysis time, fibrinogen, and platelet count were performed twice in the cold months (December and March) and twice in the warm months (June and September). Significantly higher BMI (26.8 versus 26.2 kg/m2, P < 0.01), glucose (5.5 versus 5.1 mmol/l, P < 0.01), total cholesterol (5.61 versus 5.32 mmol/l, P < 0.05), low-density lipoprotein cholesterol (3.63 versus 3.34 mmol/l, P < 0.05), triglycerides (1.79 versus 1.61 mmol/l, P < 0.01), Lp(a) (270.7 versus 237.5 mg/l, P < 0.01), fibrinogen level (3.50 versus 2.95 g/l, P < 0.00001), platelet count (212 x 10(9) versus 173 x 10(9)/l, P < 0.01) and significantly lower high-density lipoprotein cholesterol level (1.22 versus 1.28 mmol/l, P < 0.05) were observed in the cold months compared with the warm months. Significant seasonal variation of t-PA activity (1.19 versus 0.87 IU/ml, P = 0.015) and t-PA antigen (8.5 versus 7.3 ng/ml, P = 0.05) was demonstrated only in subjects with CAD. Clustering of peak values of several metabolic and haemostatic coronary risk factors was observed in winter months. This variation might be of aetiopathogenetic importance for the seasonal pattern of acute myocardial infarction.

Fibrinolytic parameters and insulin resistance in young survivors of myocardial infarction with heterozygous familial hypercholesterolemia

A characteristic feature of patients with heterozygous familial hypercholesterolemia (FH) is the premature occurrence of coronary artery disease because of elevated LDL cholesterol levels. Hyperinsulinemia and insulin resistance, important characteristics of the cardiovascular dysmetabolic syndrome (CDS), were found to be associated with coronary artery disease in FH subjects, as in the general population. We investigated whether hypofibrinolysis, as part of CDS, is independently associated with symptomatic coronary artery disease in these high-risk patients. Clinical examination (body mass index, waist circumference, blood pressure) and blood analysis (plasma tissue plasminogen activator (t-PA) antigen, plasminogen activator inhibitor (PAI-1) antigen and activity, fibrinogen, serum lipids and lipoproteins, fasting glucose and insulin) were carried out in 39 male patients with heterozygous FH (aged 46.6 +/- 8.8 years). Insulin resistance was calculated using the homeostasis model assessment (HOMA) mathematical model. Thirteen of the patients had suffered a myocardial infarction (MI) 5 to 8 years ago (aged 47.8 +/- 6.1 years) and 26 were free of coronary artery disease (aged 45.9 +/- 9.9 years). There was no difference in total and LDL cholesterol between the two groups. Patients with previous myocardial infarction had significantly higher levels of insulin, insulin resistance, triglycerides, t-PA antigen, PAI-1 antigen and activity, and significantly lower values of HDL cholesterol. Other widely recognised risk factors for coronary artery disease, such as smoking, systolic and diastolic blood pressure, obesity and age, did not differ significantly between the groups. In the logistic regression model, PAI-1 antigen, as a marker of hypofibrinolysis, emerged as an independent risk factor for the occurrence of myocardial infarction (odds ratio 1.55; p = 0.02). In summary our results suggest that the impairment of fibrinolytic activity resulting from elevated levels of PAI-1 antigen and activity and t-PA antigen is an independent variable in CDS associated with the premature occurrence of myocardial infarction in male patients with FH.