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Biomedical subjects

D G Beevers

Publications and source records attributed to D G Beevers.

At least 109 records · Page 6Linked to original sources

Obstetric and neonatal outcome following chronic hypertension in pregnancy among different ethnic groups.

We retrospectively studied pre-eclampsia rate and obstetric outcome in a cohort of 436 pregnancies amongst 318 women of different ethnic backgrounds attending an antenatal hypertension clinic from 1980-1997, identifying 152 women (213 pregnancies) with chronic essential hypertension. The ethnic breakdown was: White, 64 (30.0%) pregnancies in 48 (31.5%) women; Black/Afro-Caribbean, 79 (37.1%) pregnancies in 56 (36.8%) women; and Indo-Asians, 70 (32.3%) pregnancies in 48 (31.6%) women. The prevalences of pre-eclampsia in White, Black and Indo-Asian women were 17.2%, 12.7% and 18.6%, respectively (p = 0.58). Pregnancies of Indo-Asian women were of shorter gestation, and babies in this group also had lower birth weight and ponderal index compared to those of White and Black women (all p < 0.05). The proportions of overall perinatal mortality were 1.6% for Whites (1/64), 3.8% for Blacks (3/79) and 10.0% for Indo-Asians (7/70), suggesting increased risk in the Indo-Asian group. Indo-Asian women with chronic essential hypertension need careful antenatal care and observation during pregnancy.

Africa↗

Chlamydia pneumoniae antibodies in severe essential hypertension.

Several studies have implied an association between Chlamydia pneumoniae (C. pneumoniae) and cardiovascular disease. Our study was designed to determine whether this organism is associated with severe essential hypertension in a multiracial British population. Antibodies to C. pneumoniae were measured by microimmunofluorescence in 123 patients with chronic severe hypertension and 123 control subjects, matched for ethnic origin, age, sex, and smoking habit, admitted to the same hospital with various noncardiovascular, nonpulmonary disorders. Previous infection was defined by IgG 64 to 256, provided that there was no detectable IgM. Multiple regression analyses of matched and unmatched data were used to investigate the influences of antibody levels and potential confounding factors (ethnic origin, age, sex, smoking habit, diabetes mellitus, and social deprivation) on hypertension. A portion of the hypertensive patients underwent echocardiography, estimation of left ventricular mass index, and measurements of fibrinogen, D-dimer, and von Willebrand factor concentrations. Thirty-five percent of hypertensive patients and 17.9% of matched control subjects had antibody titers consistent with previous C. pneumoniae infection. The hypertensive patients differed significantly from their matched control subjects in their level of previous infection, with an odds ratio of 2.5 (95% confidence interval, 1.3 to 4.7). There were no significant differences in antibody levels between patients with left ventricular hypertrophy and those without it. Fibrinogen, D-dimer, and von Willebrand factor concentrations were not significantly associated with antibody levels. These data support an association of C. pneumoniae with severe essential hypertension. They provide no evidence of a predisposition to develop left ventricular hypertrophy in hypertensive patients with C. pneumoniae infection or of associations with hypercoagulability or endothelial dysfunction.

Antibodies, Bacterial↗

Chlamydia pneumoniae antibody titers are significantly associated with acute stroke and transient cerebral ischemia: the West Birmingham Stroke Project.

BACKGROUND AND PURPOSE: Several studies have implied an association between Chlamydia pneumoniae and atherosclerosis. Our research was designed to investigate the association of this organism with strokes and transient cerebral ischemia. METHODS: Antibodies to C pneumoniae were measured in 176 patients with stroke or transient cerebral ischemia and 1518 control subjects with noncardiovascular, nonpulmonary disorders. Acute infection or reinfection was defined by IgG > or =512 or IgM > or =8 or fourfold rise in IgG, and previous infection was defined by IgG 64 to 256 or IgA > or =8. Logistic regression was used to examine the influences of ethnic origin, age, sex, smoking habit, diabetes mellitus, steroid medication, and social deprivation on antibody levels. Some patients underwent CT and carotid ultrasound examinations and cholesterol, triglyceride, fibrinogen, and von Willebrand factor estimations. RESULTS: We found that 13.6% of stroke/transient ischemic attack (TIA) patients and 5.7% of control subjects had antibody titers suggesting acute C pneumoniae (re)infection, while 32.4% of stroke/TIA patients and 12.7% of control subjects had titers suggesting previous infection (P<.05). Stroke/TIA patients differed from control subjects in their levels of acute and previous infection, with adjusted odds ratios of 4.2 (95% CI, 2.5 to 7.1) and 4.4 (95% CI, 3.0 to 6.5), respectively. These did not differ notably between strokes resulting from major nonhemorrhagic infarcts, small-vessel infarcts, or hemorrhage. Cholesterol, triglyceride, fibrinogen, and von Willebrand factor concentrations showed no apparent association with titers. CONCLUSIONS: These data support the association of cerebral vascular disease with previous C pneumoniae infection and the association of stroke and transient cerebral ischemia with recrudescence of infection.

Adolescent↗

Relation of endothelium, thrombogenesis, and hemorheology in systemic hypertension to ethnicity and left ventricular hypertrophy.

Although the arterial tree is exposed to increased pressure in hypertensive patients, paradoxically, the complications of hypertension (heart attacks, stroke) are mainly thrombotic rather than hemorrhagic. Patients with left ventricular (LV) hypertrophy are at high risk of the complications of hypertension. We performed a cross-sectional study of 178 patients attending a hypertension clinic in a city center teaching hospital, and measured plasma levels of the soluble adhesion molecule P-selectin (associated with platelet activity/function and atherosclerosis), the von Willebrand factor (vWf; a marker of endothelial dysfunction), fibrin D-dimer (an index of thrombogenesis), plasminogen activator inhibitor (PAI, an index of fibrinolysis), lipoprotein(a) (Lp(a), associated with thrombogenesis and atherogenesis) and hemorheological indexes (fibrinogen, hematocrit, plasma viscosity, hemoglobin) in patients with essential hypertension, in whom the LV mass and LV mass index were determined using echocardiography. The 178 patients (86 men, mean age 54 +/- 15 years) were compared with 47 normotensive healthy controls (aged 56 +/- 20 years). Hypertensive patients had higher P-selectin, PAI, vWf, fibrin D-dimer, Lp(a), plasma fibrinogen, and plasma viscosity when compared with controls. Black hypertensive patients had higher Lp(a) levels and LV septal and posterior wall thickness on echocardiography, but lower plasma PAI levels. Patients with LV hypertrophy (defined as a LV mass index > 134 g/m2 in men or > 110 g/m2 in women) had higher plasma fibrinogen compared with those without LV hypertrophy. Systolic blood pressures were significantly correlated to age, plasma viscosity, plasma fibrinogen, and vWf. Diastolic blood pressures were significantly correlated with age and plasma fibrinogen. Fibrinogen levels were correlated with LV mass, LV mass index, left atrial size, plasma viscosity, and vWf. Fibrin D-dimer levels were significantly correlated with vWf and fibrinogen levels. Thus, hypertensive patients have high plasma fibrinogen levels, thrombogenesis, and impaired fibrinolysis (as indicated by high D-dimer and PAI levels, respectively), platelet activation (raised soluble P-selectin), and endothelial dysfunction (high vWF). The high plasma fibrinogen levels were related to blood pressures, LV mass index (and LV hypertrophy), and left atrial size. These abnormalities in hemorheologic factors and markers of thrombogenesis and endothelial function may act synergistically to increase the risk of thrombogenesis and atherosclerosis in hypertensive patients.

Adult↗

Effect of atenolol on birth weight.

To investigate the possible harmful effects of early antihypertensive drug therapy with atenolol versus other therapies on pregnancy outcome, we reviewed the records of 398 women referred to our antenatal hypertension clinic between 1980 and 1995. Babies born to women taking atenolol were significantly lighter than babies born to women taking other beta blockers, other antihypertensive drugs, or no therapy, suggesting that atenolol might be detrimental in early pregnancy.

Analysis of Variance↗

Ambulatory blood pressure in pregnancy and fetal growth.

BACKGROUND: Retarded growth in utero has been linked with high blood pressure and other risk factors for cardiovascular disease in adult life. However, the influence on fetal growth of the maternal blood pressure during pregnancy is not well defined. In a prospective study, we examined the relation between maternal ambulatory blood pressure during pregnancy and indices of fetal growth. METHODS: We studied 209 healthy nulliparous pregnant women referred to an inner-city district general hospital (86% of 244 consecutively referred women who met the study criteria). 24 h ambulatory blood-pressure recordings were obtained in early (median 18 weeks [IQR 17-18]) mid (28 weeks [28]), and late (36 weeks [36]) gestation. Eight infants delivered before 32 weeks' gestation were excluded from the analysis. FINDINGS: A 5 mm Hg (1 SD) increase in mean 24 h diastolic blood pressure at 28 weeks' gestation was associated with a 68 g (95% Cl 3-132) decrease in birthweight; a similar change in diastolic pressure at 36 weeks' gestation was associated with a 76 g (24-129) decrease in birthweight. These associations were independent of potential confounders (maternal age, height, weight, cigarette smoking, alcohol intake, ethnic origin, pregnancy hypertension syndromes, and preterm birth). Maternal mean 24 h diastolic blood pressure at 28 weeks' gestation was also inversely associated with the infant's ponderal index at birth in multivariate analysis (p = 0.06). Higher maternal ambulatory blood pressure at 28 weeks' and 36 weeks' gestation also predicted lower head circumference, although these associations were dependent on birthweight. Associations between ambulatory systolic blood pressure and indices of fetal growth were weak and inconsistent and ambulatory blood pressure at 18 weeks' gestation did not predict fetal growth. INTERPRETATION: There is a continuous inverse association between fetal growth and maternal blood pressure, throughout the range seen in normal pregnancy. Maternal blood pressure may be an important confounding factor in the reported associations between fetal growth retardation and adult hypertension and cardiovascular disease.

Adult↗

Effects of hormone-replacement therapy on hemostatic factors, lipid factors, and endothelial function in women undergoing surgical menopause: implications for prevention of atherosclerosis.

Women with premature menopause are at high risk for vascular compications associated with thrombogenesis and atherogenesis. The use of hormone-replacement therapy (HRT), however, may protect against these complications. Hemostatic abnormalities and endothelial function are closely related to the processes of thrombogenesis and atherogenesis. The purpose of the study was to evaluate the effects of premature menopause on markers of hemostasis, platelet function, and endothelial function and the effects of starting HRT. This is a prospective longitudinal study of premenopausal women undergoing surgical menopause in whom estrogen HRT is started. We measured sequential changes in plasma levels of the hemostatic factors (fibrinogen, fibrin D-dimer, and plasminogen activiator inhibitor [PAI]), markers of platelet function (soluble leukocyte adhesion molecule P-selectin) and endothelial function (von Willebrand factor [vWf], soluble thrombomodulin [sTM], and tissue plasminogen activator [TPA]), and serum lipid levels, including lipoprotein A. Twenty-seven premenopausal women (mean age 43.6 +/- 6.5 years) undergoing hysterectomy and bilateral salpingo-oophrectomy were studied. In the postsurgical menopausal state (visit 2), there was a significant elevation in sTM levels (paired Wilcoxon test, p = 0.008). There was also a trend toward higher median soluble P-selectin, PAI, and mean TPA levels and lower vWf levels. After 6 weeks of HRT (visit 3), there was a significant reduction in mean vWf (paired Wilcoxon test, p = 0.0026), sTM (p = 0.039), and TPA levels (p = 0.02) compared with premenopausal levels. There were no significant changes in plasma fibrinogen, fibrin D-dimer, and PAI levels at visit 2 or visit 3 compared with premenopausal levels. There was a significant increase in serum lipoprotein A (paired Wilcoxon test, p = 0.008), cholesterol, and triglyceride levels after surgical menopause (paired t test, p < 0.01). Lipoprotein A and cholesterol levels after HRT (visit 3) were not significantly different from prehysterectomy levels, although triglyceride levels were increased further. HRT results in a significant reduction in vWf, sTM, and TPA levels, suggesting beneficial effects on endothelial function and atherogenesis. Although there was a significant increase in serum lipoprotein A and cholesterol levels after surgical menopause, lipoprotein A and cholesterol levels after HRT were not significantly different from presurgery levels. These observations are consistent with the beneficial effects of HRT in cardiovascular hemodynamics and cardiovascular disease.

Adult↗

Calcium channel blockers and cardiac mortality in the treatment of hypertension: a report from the Department of Health Hypertension Care Computing Project (DHCCP).

OBJECTIVE: A case control study has reported a 60% higher risk of myocardial infarction in hypertensives treated with a calcium channel blocker (CCB). We examined the Department of Health Hypertension Care Computing Project (DHCCP) data to see if we could confirm or refute this suggestion. DESIGN: Two case control studies, matched and unmatched, plus two longitudinal studies from 1 year of presentation, one for all subjects given a CCB for more than 1 year compared with those not given this drug, and the second comparing survival on the different drugs initially given between 3 and 12 months of follow-up. SUBJECTS: A total of 9328 subjects were included in the analyses and 2154 died. Of these, 6406 received one or more of the following index drugs: 26% a calcium channel blocker (CCB); 84% a diuretic; 29% alpha methyldopa; 12% a beta-blocker (BB); and 11% an angiotensin-converting enzyme (ACE) inhibitor. The CCBs were nifedipine, diltiazem or verapamil. RESULTS: In the case control studies a group given diuretics +/- other treatments (but not including one of the index drugs) provided a reference group with a relative risk (RR) of 1.0. In the matched case control study the adjusted RR for a CCB without a diuretic was 1.32 (95% CI 0.64-2.70) for IHD mortality and 1.05 (95% CI 0.60-1.84) for cardiovascular mortality. Similar results were observed for methyldopa, BBs and ACE inhibitors. The results in the unmatched case control analysis were also similar. The longitudinal study comparing all those treated for over 1 year with a CCB with all other treatments showed a RR for total mortality of 1.03 (95% CI 0.85-1.25). The longitudinal study of total mortality according to treatment initiated at 3-12 months found results of a similar magnitude for CCBs, methyldopa and BBs. CONCLUSIONS: The reference diuretic group had less severe cardiovascular disease than other groups. Treatment with a CCB, BB or methyldopa was associated with an excess mortality in comparison with this reference group. The excess was similar in the different drug groups.

Adolescent↗