Cardiovascular disease in women : an epidemiological study of atherogenic factors

Cardiovascular disease is generally considered to be a disorder of men. One reason for this is the low incidence of the disease in women at younger age. At older age. however. cardiovascular disease also becomes the most important cause of mortality in women: at age 40. 15% of the mortality in women is due to this disease compared to 45% at age 70.1 Currently. there is an increased recognition of the public health importance of cardiovascular disease in women. but data on cardiovascular risk factors are limited. The investigation of the determinants of cardiovascular disease in women was the main purpose of the work underlying the studies presented in this thesis. Traditionally. epidemiologists have studied cardiovascular disease by examination of the relation between potential risk factors and the prevalence or incidence of cardiovascular events. One of the disadvantages of these studies is that events reflect a near end-stage of disease which limits the study of risk factors at earlier stages of disease. The majorunderlyingprocess of cardiovascular disease is atherosclerosis. To study atherosclerosis non-invasively in asymptomatic non-hospitalized subjects it is necessary to rely on vessels other than the coronary or cerebral. In the studies presented in this thesis the presence of radiographically detectable calcified plaques in the aorta was used as a measure of atherosclerosis. Its ability to reflect a generalized process was studied by examination of the association of aortic atherosclerosis with cardiovascular morbidity and mortality using follow-up data of 1.359 men and 1,597 women of the EPOZ study (Epidemiological Preventive Organization Zoeterrneer). and of 2,336 men and 2,873 women of the Framingham Study

The influence of charge-mode operation of a XeCl laser on the beam profile

The shape of the beam profile of a discharge excited XeCl excimer laser using a spiker-sustainer electrical circuit has been varied from a `bell¿-, through a `top-hat¿-, to a `camel-back¿-profile by varying the delay between the spiker pulse and the main-current with the circuit operating in the charge-mode. Fine-tuning of the beam profile can be done by varying the charging voltage of the main pulse forming network or the temperature of a gas purifier regulating the Xe and HCl partial pressures

Serum cholesterol is a risk factor for myocardial infarction in elderly men and women: The Rotterdam Study

Objective. To investigate the associations of serum total and HDL cholesterol with the risk of myocardial infarction in men and women of 55 years and over. Design. The Rotterdam Study is a population-based prospective cohort study. In total 2453 men and 3553 women of 55 years and older were included in this study. The mean duration of follow-up was 4 years. Main outcome measures. Relative risks were estimated with Cox's proportional- hazard analysis. Cholesterol was analysed as a continuous variable and in sex-specific quartiles. Results. In subjects aged 55 years and older the relative risk of myocardial infarction was 1.9 in men (95% confidence interval 1.1-3.3) and 3.2 in women (1.5-6.4) in the highest compared to the lowest serum total cholesterol quartile (Q4 vs. Q1). In men and women of 70 years and older, total cholesterol remained an important risk factor for myocardial infarction (Q4 vs. Q1 relative risk 3.2; 1.3-7.7 and 2.9; 1.3- 6.6, respectively). For HDL cholesterol, the relative risk in the highest compared to the lowest quartile (Q4 vs. Q1) was 0.5 in men (0.3-0.9) and 0.4 in women (0.2-0.9). HDL cholesterol was a weaker predictor in men after the age of 70 (Q4 vs. Q1 0.8; 0.3-2.1). In women of 70 years and older the relative risk was also not significant (Q4 vs. Q1 0.6; 0.3-1.3), although the trend over the quartiles was still significant. Conclusion. Serum total cholesterol remains an important risk factor for myocardial infarction in men and women aged 70 years and older, whilst HDL cholesterol at older age remains important in women only

The injector microtron for the TEUFEL infrared laser

Progress is reported on a 25 MeV injector racetrack microtron for a 10 ¿m radiation free electron laser (TEUFEL project). The accelerator exhibits transverse focusing in 180° inhomogeneous two-sector dipole magnets which are slightly rotated with respect to each other in the bending plane. This provides closed orbits, isochronism and a large transverse acceptance. Details on this unconventional microtron focusing system will be given. An analytical treatment, based on conformal mapping, of the field near pole boundaries and at the hill-valley boundaries in the microtron dipole is compared with Poisson calculated results and with field measurements. The design of a model accelerating cavity is presented together with field measurements based on the perturbation ball method

Fetal kidney volume and its association with growth and blood flow in fetal life: The Generation R Study

An adverse fetal environment may lead to smaller kidneys and subsequent hypertension with renal disease in adult life. The aim of our study was to examine whether maternal characteristics, fetal growth, fetal blood flow redistribution, or inadequate placental perfusion in different periods of fetal life affect kidney volume in late fetal life. We also determined if fetal kidney volume was linked to the amount of amniotic fluid. In a population-based prospective study from early fetal life, fetal growth characteristics and fetal blood flow parameters were assessed by ultrasound and Doppler examinations in 1215 women in mid- and late-pregnancy. Kidney volume was measured in late pregnancy. Maternal height and pre-pregnancy weight were associated with kidney volume. After adjustment for the same characteristics in late pregnancy, fetal growth and blood flow in mid-pregnancy were not associated with kidney volume in late pregnancy. In late pregnancy, however, all fetal growth parameters were positively linked with kidney volume. The largest effect on kidney volume was found for abdominal circumference. Signs of fetal blood flow redistribution and increased placental resistance were associated with decreased kidney volume in late pregnancy. Amniotic fluid volume was positively associated with kidney volume. Our study shows that maternal anthropometrics, fetal growth, fetal blood flow redistribution, and raised placental resistance all correlate with kidney volume

Variance heterogeneity analysis for detection of potentially interacting genetic loci: Method and its limitations

Background: Presence of interaction between a genotype and certain factor in determination of a trait's value, it is expected that the trait's variance is increased in the group of subjects having this genotype. Thus, test of heterogeneity of variances can be used as a test to screen for potentially interacting single-nucleotide polymorphisms (SNPs). In this work, we evaluated statistical properties of variance heterogeneity analysis in respect to the detection of potentially interacting SNPs in a case when an interaction variable is unknown.Results: Through simulations, we investigated type I error for Bartlett's test, Bartlett's test with prior rank transformation of a tr

Progression of aortic calcification is associated with metacarpal bone loss during menopause: a population-based longitudinal study

offerosclerosis and osteoporosis are major causes of morbidity and mortality in postmenopausal women and have been suggested to be associated. No study has examined whether progression of atherosclerotic calcification is associated with bone loss. In the present study, we examined progression of aortic calcification, diagnosed by radiographic detection of calcified deposits in the abdominal aorta, in relation to metacarpal bone loss, as assessed by metacarpal radiogrammetry, during menopause. Initially premenopausal women (n=236), aged 45 to 57 years at baseline, were followed for 9 years. We additionally assessed the cross-sectional association between the extent of aortic calcification and metacarpal bone mass and density in 720 postmenopausal women. Twenty-five percent of women going through menopause showed progression of aortic calcification. The average loss of metacarpal bone mass among women with progression of aortic calcification was 3.2 mm(2), and their loss of metacarpal bone density was 7.2 mm(2) %, whereas in women without progression of aortic calcification, these losses were 2.0 mm(2) and 5.6 mm(2) %, respectively, adjusted for age and years of follow-up (P<0.05). Additional adjustment for age at menopause, body mass index, blood pressure, smoking, diabetes mellitus, and use of hormone replacement therapy, thiazide, and loop diuretics did not influence these results. In postmenopausal women, a graded inverse cross-sectional association between the extent of aortic calcification and metacarpal bone mass and density was found. In conclusion, our results indicate that progression of atherosclerotic calcification is associated with increased bone loss in women during menopause

Inverse association of tea and flavonoid intakes with incident myocardial infarction: the Rotterdam Study

BACKGROUND: Dietary flavonoids may protect against cardiovascular disease, but evidence is still conflicting. Tea is the major source of flavonoids in Western populations. OBJECTIVE: The association of tea and flavonoid intake with incident myocardial infarction was examined in the general Dutch population. DESIGN: A longitudinal analysis was performed with the use of data from the Rotterdam Study-a population-based study of men and women aged >or=55 y. Diet was assessed at baseline (1990-1993) with a validated semiquantitative food-frequency questionnaire. The analysis included 4807 subjects with no history of myocardial infarction, who were followed until 31 December 1997. Data were analyzed in a Cox regression model, with adjustment for age, sex, body mass index, smoking status, pack-years of cigarette smoking, education level, and daily intakes of alcohol, coffee, polyunsaturated fat, saturated fat, fiber, vitamin E, and total energy. RESULTS: During 5.6 y of follow-up, a total o

Spatial QRS-T angle predicts cardiac death in a general population

AIMS: The aim of this study was to assess the prognostic importance of the spatial QRS-T angle for fatal and non-fatal cardiac events. METHODS AND RESULTS: Electrocardiograms (ECGs) were recorded in 6134 men and women aged 55 years and over from the prospective population-based Rotterdam Study. Spatial QRS-T angles were categorized as normal, borderline or abnormal. Using Cox's proportional hazards model, abnormal angles showed increased hazard ratios of cardiac death (age-and sex-adjusted hazard ratio 5.2 (95% CI 4.0-6.8)), non-fatal cardiac events (2.2 (1.5-3.1)), sudden death (5.6 (3.7-8.5)) and total mortality (2.3 (2.0-2.7)). None of the classical cardiovascular and ECG predictors provided larger hazard ratios. After adjustment for these predictors, the association of abnormal spatial QRS-T angles with all fata