ISSN:0263-6352    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

BackgroundTobacco smoking is associated with a higher prevalence of atherosclerosis and respiratory disease.ObjectiveTo investigate differences between hemodynamic and biochemical findings in smokers and nonsmokers in the two sexes separately in the Tecumseh population.MethodsWe studied 851 subjects. They were divided according to smoking habits into group 1, nonsmokers (258 men and 234 women); and group 2, smokers (185 men and 174 women).ResultsUnpaired Student's t-tests and nonparametric tests were performed to determine the between-group P-values. Only hematocrit differed significantly between smokers and nonsmokers in both sexes (43.9 ± 0.2 and 44.6 ± 9.3%,P< 0.05 in men; 39.2 ± 0.3 and 40.3 ± 0.3%,P= 0.007 in women, respectively in nonsmokers and smokers). Triglycerides (80.6 ± 3.8 and 99.6 ± 4.3 mg/dl,P< 0.001), left ventricular mass index (95.4 ± 1.9 and 100.0 ± 1.2 g/m2,P= 0.008), and posterior wall thickness (9.5 ± 0.1 and 9.71 ± 0.01 mm,P= 0.044) were elevated and high-density lipoproteins were decreased (48.7 ± 0.8 and 44.5 ± 0.9 mg/dl,P< 0.01) only in women smokers.After adjustment for home systolic blood pressure and body mass index the differences in women remained significant except for posterior wall thickness.ConclusionTobacco smoking is deleterious to both sexes but it appears to be particularly harmful to women. Our data can, in part, explain why the relative risk of myocardial infarction is higher in women than it is in men.

ISSN:0263-6352    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

ObjectiveThe aim of this study was to investigate the cross-sectional relationship between arterial blood pressure and cognitive impairment in a group of elderly subjects, controlling for such confounding variables as age, education, depression, drug use and antihypertensive treatment.Design and settingA cross-sectional survey in Campania, a region in southern Italy.Subjects and methodsA random sample of 1339 elderly subjects aged 65–95 years (mean 73.9 ± 6.2 years) selected from the electoral rolls was interviewed by trained physicians. Sociodemographic characteristics, results of Mini-Mental State Examination (MMSE), Geriatric Depression Scale (GDS), blood pressure and whether antihypertensive treatment was being administered were recorded. When subjects with neurological diseases and those under psychotropic therapy were excluded from the analyses, the population numbered 1106.ResultsThe MMSE score was less than 24 for 27.9% of the subjects and the mean GDS score was 10.8 ± 6.3. The mean systolic blood pressure (SBP) was 145.3 ± 19.0 mmHg and the mean diastolic blood pressure (DBP) was 82.0 ± 9.2 mmHg. Logistic regression analysis showed that female sex, age, GDS score and DBP but not SBP were predictive of cognitive impairment.Educational level and antihypertensive treatment, on the contrary, play a protective role. DBP was associated with cognitive impairment in subjects aged 75 years (odds ratio 1.62, 95% confidence interval 1.16–2.25) and over (odds ratio 5.16, 95% confidence interval 1.50–17.71) but not in those aged 65–74 years.ConclusionDBP but not SBP is predictive of cognitive impairment in subjects aged 75 years and over without neurological disorders independently from sex, age, education, GDS and antihypertensive treatment.

ISSN:0263-6352    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

ObjectiveTo evaluate the effects of a westward transmeridian flight over six time zones (from Milan to New York) on ambulatory blood pressure monitoring (ABPM) in normotensive individuals.MethodsEighteen normotensive subjects (blood pressure < 140/90 mmHg), 11 men and seven women, of mean age 38.3 years, were studied. On the day of travel they underwent 26 h noninvasive ABPM (started at 1100h); the take-off time was 1200 h and the landing time was 8 h later, at 1400 h New York time (2000 h Italian time). Subjects were requested not to sleep until 2300 h and to get up at 0700 h the following morning. The results were compared with those of a 26 h ABPM performed in Italy the week before during which they slept from 2300 h to 0700 h.ResultsDuring the flight blood pressure and heart rate did not change compared with values during the corresponding time interval of the control day. After the landing, during the New York afternoon and evening (corresponding to the Italian sleeping time), blood pressure and heart rate remained unchanged, whereas during the night they decreased significantly, although their drop was less pronounced than that during the control day.ConclusionThe results of this study indicate that the decrease in blood pressure during sleep is the result of sleep itself rather than of the actual time of day.

ISSN:0263-6352    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

ObjectiveTo measure blood pressure accurately, by developing a new algorithm and an indirect method employing a non-elastic cuff with a photosensor.Design and methodsA non-elastic cuff was wrapped around the brachium. A reflecting plate (10 mm × 40 mm) was sited on the inner central part of the cuff on the arterial side. On the opposite side of the cuff, a photosensor consisting of light-emitting and light- receiving elements was positioned. Oscillation due to arterial pulsation was measured photologically during cuff inflation. Cessation of oscillation was taken as the systolic blood pressure (SBP) and, when the delay time between photo-oscillation and cuff-pressure oscillation upstrokes was at its minimum, the transition from rapid to more stable changes in photo-oscillation was taken as the diastolic blood pressure (DBP; the delta-algorithm). We compared the blood pressures measured directly in the brachial artery with those obtained by this method and by the conventional auscultatory method in 10 normotensive and 26 hypertensive subjects [12 women and 24 men, mean age 45 ± 16 years (mean ± SD), with mean brachial circumference 27 ± 2.6 cm]. The blood pressure of each subject was measured simultaneously by the direct and indirect methods five times.ResultsErrors (differences from direct blood pressure measurements) produced with this new method [SBP–0.8 ± 3.1 mmHg, (mean ± SD) DBP 0.6 ± 2.8 mmHg] were significantly smaller than errors obtained by use of the auscultatory method (SBP −7.4 ± 5.6 mmHg, DBP 3.0 ± 7.1 mmHg; P < 0.001, n = 180). The delta-algorithm was easily applicable to an automatic blood pressure measuring device.ConclusionThis new photo-oscillometric method was more accurate than the auscultatory method for measuring blood pressure. The delta-algorithm is logical and will be useful for accurate blood pressure measurement.

ISSN:0263-6352    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

ObjectiveTo clarify the prevalence of hyperinsulinemic subjects among young, nonobese, Japanese men, and to evaluate characteristics, in particular, of sympathetic nerve system activity and lipid fractions in hyperinsulinemic subjects.MethodsNorepinephrine, plasma insulin, and lipid fractions were measured in 512 normotensive, 124 borderline hypertensive (BHT) and 88 established hypertensive (EHT) subjects, matched for age and body mass index, after they had fasted overnight.ResultsHyperinsulinemia defined as mean fasting plasma insulin + 2SD in normotensives or more was found in 8% of all subjects (normotensive and hypertensive subjects,P= 0.018), 6% of normotensives, 10% of BHT (P= 0.28, versus normotensives), 18% of EHT (P= 0.005, versus normotensives), and 12% of hypertensives (P= 0.019, versus normotensives). The hyperinsulinemic (fasting insulin ≥mean + 2SD in normotensive) subjects had higher plasma norepinephrine levels in all blood pressure groups than did nonhyperinsulinemic (< mean + 2SD) subjects (normotensivesP< 0.05, BHTP< 0.01, and EHTP< 0.05). Hyperinsulinemic normotensives had higher blood pressure levels than did nonhyperinsulinemic ones (P< 0.05); however, blood pressure levels in hyperinsulinemic BHT and EHT were similar to those in nonhyperinsulinemic subjects. Triglyceride in BHT and EHT was greater than that in normotensives (P< 0.05), and that in hyperinsulinemic subjects was greater than that in nonhyperinsulinemic subjects (P< 0.05). On the other hand, high-density lipoprotein cholesterol in hyperinsulinemic BHT and EHT was significantly lower than that in nonhyperinsulinemic BHT (P< 0.05) and EHT (P< 0.01).ConclusionThese results demonstrated that the prevalence of hyperinsulinemia among the present sample of young, nonobese, Japanese men was 12% and that the prevalence increased with blood pressure elevation. Furthermore, hypertriglyceridemia and sympathetic nerve hyperactivity appear to be related to hyperinsulinemia and the emergence of hypertension.

ISSN:0263-6352    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

ObjectivesTo determine whether hyperinsulinemia is associated with early atherosclerosis in normotensive men of a work site population.Design and methodsSix hundred and seventeen subjects were screened from 8678 male transport workers for the further examination of cardiovascular disease and diabetes. Subjects aged less than 40 years, those with hypertension or diabetes, or both, and those being administered medications for hyperlipidemia were excluded. Finally, 164 normotensive, nondiabetic subjects were enroled. The intima-media thickness (IMT) was measured by B-mode ultrasonography with a 7.5 MHz probe. Electrocardiography, a 75 g oral glucose-tolerance test (OGTT) and blood chemistry measurements were also performed. The sum of insulin values (ΣIRI) and the ratio of the sum of insulin values to blood glucose levels (ΣIRI/ΣBG) in the 75 g OGTT were used as markers of hyperinsulinemia.ResultsThe mean age of the subjects was 52 ± 5 years (mean ± SD). In a univariate analysis, IMT was associated with age, systolic blood pressure, body mass index, ΣIRI, and ΣIRI/ΣBG. Multivariate analysis showed that age, total cholesterol, and SIRI (or ΣIRI/ΣBG) were independent risk factors for IMT.ConclusionsThese results suggest that, in addition to age and total cholesterol, hyperinsulinemia as assessed by an OGTT is associated with early atherosclerosis in normotensive, nondiabetic men of a work site population.

ISSN:0263-6352    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

ObjectiveTo investigate whether mutations in the C-terminus of the three subunits of the rat epithelial sodium channel (αβγ-rENaC) contribute to the hypertensive phenotype in five rat models for essential hypertension.DesignWe sequenced the C-terminal regions of α-, β- and γ-rENaC genes in five different hypertensive rat strains [spontaneously hypertensive rats (SHR), Dahl salt-sensitive (SS/Jr) rats, Milan hypertensive (MHS) rats, Sabra hypertensive (SBH) rats and Lyon hypertensive rats (LHR)] and their normotensive controls [Wistar–Kyoto (WKY) rats, Dahl salt-resistant (SR/Jr) rats, Milan normotensive (MNS) rats, Sabra normotensive (SBN) rats and Lyon normotensive rats (LNR)]. Identified polymorphisms were tested for cosegregation with blood pressure as well as for increased epithelial sodium channel (ENaC) activity.MethodsGenomic DNA extracted from hypertensive and normotensive rat strains was amplified by the polymerase chain reaction and polymerase chain reaction fragments were sequenced. Cosegregation analysis was performed to test for correlations between blood pressure and different genotypes. The effects of a polymorphism on ENaC activity were assessed by functional expression inXenopus laevisoocytes. The chromosomal location of the gene for γ-ENaC was determined by linkage analysis in an F2 (MHS × MNS) population.ResultsWe found no polymorphisms at the C-terminus of α- and β-rENaC in the five rat models tested. We identified two polymorphisms at the C-terminus of the γ-subunit, one leading to an amino acid change. Milan strains (MNS and MHS) were polymorphic for this mutation. By cosegregation analysis we could exclude the possibility that there was a correlation between blood pressure and this polymorphism. Functional expression of the polymorphism caused no increase in ENaC activity assessed by measurement of the amiloride-sensitive sodium current inXenopusoocytes. The gene for the γ-ENAC was located on rat chromosome 1.ConclusionsNo polymorphisms at the C-terminus of the three subunits of the epithelial sodium channel cosegregating with blood pressure were detected in five different genetic rat models for hypertension. If an altered ENaC activity contributes to the pathogenesis of hypertension in these rats, it must thus arise from mutations in other parts of the protein, from mutations outside the coding region impairing the proper regulation of one of the subunits or from mutations in an ENaC-associated protein.

ISSN:0263-6352    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

ObjectiveTo evaluate the hypotensive and renal effects of atrial natriuretic peptide (ANP) in one-kidney, one clip Goldblatt hypertensive rats with and without renal arterial stenosis.MethodsThe one-kidney, one clip hypertensive rats were divided into four groups: untreated time control, ANP-infused, unclipped and unclipped plus ANP-infused. The changes in blood pressure, glomerular filtration rate and renal excretory function were determined during intravenous vehicle and ANP infusions while the renal arterial clip was in place or removed acutely. One-kidney normotensive rats infused with ANP were used for comparison.ResultsIn one-kidney control rats, ANP infusion at doses of 0.15, 0.30 and 0.45 μg/kg per min decreased the mean blood pressure from 121 ± 4 to 108 ± 5 (9%,P< 0.05), 104 ± 5 (17%,P< 0.05) and 89 ± 4 mmHg (25%,P< 0.05), respectively. There was no significant change in glomerular filtration rate. However, the absolute sodium excretion rate increased significantly, by 343 ± 66, 770 ± 91 and 786 ± 78%, respectively. A comparable magnitude of increase in the fractional sodium excretion was noted. In one-kidney, one clip hypertensive rats, the similar three doses of ANP infusion reduced blood pressure from 179 ± 7 to 162 ± 8 (8%,P< 0.05), 146 ± 9 (17%,P< 0.05) and 138 ± 8 mmHg (22%,P< 0.05), respectively. A slight but insignificant increase in renal function was observed during ANP infusion. Removal of the renal arterial clip reduced blood pressure rapidly and caused a transient increase in renal function. Subsequent infusion of ANF further reduced blood pressure but increased sodium and water excretion markedly.ConclusionThere is a blunted natriuresis and diuresis in response to ANP infusion in one-kidney, one clip hypertensive rats. Surgical removal of the clip from the renal artery restores the natriuretic and diuretic effects of ANP.

ISSN:0263-6352    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

BackgroundIn insulin-dependent diabetic subjects, heritable factors related to hypertension and cardiovascular disease are associated with nephropathy.ObjectiveTo determine the relationship of blood pressure, glycaemic control, family history of cardiovascular disease and sodium-lithium countertransport activity to the onset of proteinuria and decline in glomerular filtration.DesignA retrospective analysis of the rate of onset of proteinuria and a longitudinal study of the progression of established renal disease.SettingGuy's Hospital Diabetes Renal Clinic, a secondary referral centre.PatientsFifty-four insulin-dependent diabetic patients with nephropathy, persistent total protein excretion rate >500 mg/24 h, enrolled between 1978 and 1992.Main outcome measuresRate of decline in glomerular filtration rate. Duration of diabetes at onset of nephropathy (time to proteinuria). Blood pressure and glycosylated haemoglobin at the time of diagnosis of nephropathy (baseline). Family history of cardiovascular disease and hypertension. Erythrocyte sodium-lithium countertransport activity in a subset of patients (n = 41) not being administered renal replacement therapy in 1992.ResultsThe estimated (95% confidence interval) time to proteinuria was shortened in relation to increments in diastolic blood pressure at baseline and to a family history of cardiovascular disease in both parents [1.9 (0.2–3.2) years/10 mmHg,P< 0.05 and 6.7 (–0.3–13.7) years,P< 0.07, respectively]. During follow-up 15% (n = 8) of the patients who did not require antihypertensive therapy had slower rates of decline in glomerular filtration and lower rates of sodium–lithium countertransport activity than did those who had been administered treatment [median (range): 2.88 (0.2 to −11.28) versus 7.8 (0.1 to −20.4) ml/min per 1.73 m2/year,P< 0.05 and 0.28 (0.14–0.54) versus 0.43 (0.18–0.88) mmol/l per erythrocyte/h,P< 0.03, respectively]. In this group there was an inverse relationship between the time to proteinuria and glycosylated haemoglobin (r = −0.79,P= 0.018). For the whole group a multivariate analysis showed hypertension and initial glomerular filtration rate to be related independently to the rate of decline in renal function; glycaemic control just failed to attain statistical significance (P< 0.06).ConclusionElevation of blood pressure accelerates the onset of nephropathy and its progression; its absence, a reduced familial predisposition to cardiovascular disease, low sodium–lithium countertransport activity and good blood glucose control favour a more benign prognosis.

ISSN:0263-6352    

出版商:OVID    

年代:1997

数据来源: OVID