Biomedical subjects

J A Staessen

Publications and source records attributed to J A Staessen.

152 records · Page 9Linked to original sources

PubMedDate not supplied

Ambulatory blood pressure of adults in Novosibirsk, Russia: interim report on a population study.

OBJECTIVE: To describe the distributions of the ambulatory blood pressure in a sample drawn from the Siberian population. METHODS: In the European Project On Genes in Hypertension (EPOGH), a random population sample of 162 persons (72 men and 90 women) was investigated in Novosibirsk, Russia. Mean age (+/-SD) was 40.6+/-15.3 years. Validated oscillometric 90207 SpaceLabs monitors were programmed to obtain ambulatory blood pressure readings at intervals of 15min from 0800h to 2200h and at 30min intervals from 2200h to 0800h. Daytime and nighttime were defined using short fixed-clock time intervals, which ranged from 1000h to 2000h and from midnight to 0600h, respectively. RESULTS: In the 162 participants, of whom 54 were hypertensive, 24-h clocktime day and clocktime night blood pressures averaged 120/73, 126/79 and 110/60mmHg, respectively. Compared with daytime values, blood pressures at the clinic were 5.7/1.1mmHg lower in 108 normotensive people, but 17.0/13.1mmHg higher in 54 hypertensive patients. In the normotensive subgroup, the 95th percentiles of the 24-h clocktime day and clocktime night blood pressures were 128/81, 136/86 and 118/72mmHg, respectively. CONCLUSION: In comparison with other population surveys, the present interim report on the EPOGH study produced consistent results with respect to the distributions of the ambulatory measurements both in normotensive subjects and in the overall study population.

Adolescent↗

PubMedDate not supplied

Treatment of isolated systolic hypertension in the elderly: the Syst-Eur trial. Systolic Hypertension in Europe (Syst-Eur) Trial Investigators.

The Syst-Eur study investigated whether active antihypertensive treatment could reduce cardiovascular complications in elderly patients with isolated systolic hypertension. Patients (> or = 60 years) were randomly assigned to active treatment (n = 2398), i.e. nitrendipine, with the possible addition of enalapril and hydrochlorothiazide, or matching placebos (n= 2297). In the intention-to-treat analysis, the between-group difference in blood pressure amounted to 10.1/4.5 mm Hg (P < 0.001). Active treatment reduced the total incidence of stroke (primary endpoint) by 42% (P = 0.003), of all cardiac endpoints by 26% (P = 0.03), and of all cardiovascular endpoints combined by 31% (P < 0.001). Cardiovascular mortality was slightly lower on active treatment (-27%; P = 0.07), but all-cause mortality was not influenced (-14%; P = 0.22). For total (P = 0.009) and cardiovascular mortality (P = 0.09), the benefit of antihypertensive treatment weakened with advancing age and for total mortality it decreased with higher systolic blood pressure at entry (P = 0.05). The benefits of active treatment were not independently related to gender or to the presence of cardiovascular complications at entry. Further analyses also suggested benefit in patients who were taking nitrendipine as the sole therapy. The per-protocol analysis largely confirmed the intention-to-treat results. It can be concluded that stepwise antihypertensive drug treatment, starting with the dihydropyridine calcium channel blocker nitrendipine, improves prognosis in elderly patients with isolated systolic hypertension.

Aged↗

PubMedDate not supplied

Implications of the Systolic Hypertension in China trial.

In 1988, the Systolic Hypertension in China (Syst-China) Collaborative Group started to investigate whether active treatment could reduce the incidence of stroke and other cardiovascular complications of isolated systolic hypertension. After stratification for center, sex and previous cardiovascular complications, alternate patients (n = 1253) were assigned nitrendipine 10-40 mg daily, with the possible addition of captopril 12.5-50.0 mg daily, or hydrochlorothiazide 12.5-50.0 mg daily, or both drugs. In 1141 control patients, matching placebos were employed similarly. At entry, sitting blood pressure averaged 170 mm Hg systolic and 86 mm Hg diastolic, age averaged 66 years, and total serum cholesterol was 5.1 mmol/L. At 2 years, the between-group differences were 9.1 mm Hg systolic (95% confidence interval: 7.6-10.7 mm Hg) and 3.2 mm Hg diastolic (2.4-4.0). Active treatment reduced total stroke by 38% (p=0.01), all-cause mortality by 39% (p=0.003), cardiovascular mortality by 39% (p=0.03), stroke mortality by 58% (p=0.02) and all fatal and nonfatal cardiovascular endpoints by 37% (p=0.004). In conclusion, antihypertensive treatment prevents stroke and other cardiovascular complications in older Chinese patients with isolated systolic hypertension. Treatment of 1000 Chinese patients for 5 years could prevent 55 deaths, 39 strokes, or 59 major cardiovascular endpoints.

Aged↗

PubMedDate not supplied

Development of diagnostic thresholds for automated measurement of blood pressures in adults.

In clinical medicine, blood pressure is usually measured by conventional sphygmomanometry. Although it seems simple at first sight, this procedure is fraught with potential sources of error, which may arise from the subject, the observer, the sphygmomanometer or the overall application of the technique. Automated techniques of blood pressure measurement, such as ambulatory monitoring and self-measurement, reduce the limitations of conventional sphygmomanometry. However, the diagnostic thresholds applicable for conventional sphygmomanometry cannot be extrapolated to automated measurements. During the past 10 years criteria for normality have gradually been developed for ambulatory blood pressure (ABP) monitoring of adults. First, the distribution of the ABP in normotensive subjects and untreated hypertensive patients who had initially been recruited and classified on the basis of their conventional blood pressure was studied. Second, authors of various epidemiological studies investigated the distributions of the conventional blood pressure and the ABP in the population at large. Third, authors of several reports attempted to validate the preliminary thresholds for ambulatory monitoring by correlating the ABP to left ventricular hypertrophy, other intermediary signs of target-organ damage or the incidence of cardiovascular morbidity or mortality. Finally, clinical trials should be mounted to prove that it is beneficial to patients as well as cost-effective to diagnose and treat hypertension on the basis of ambulatory monitoring rather than solely under the guidance of conventional sphygmomanometry. For measurements of systolic/diastolic ABP in adults, the proposed upper limits of normotension are 130/80 mmHg for the 24h blood pressure and 135/85 and 120/70 mmHg for the daytime and night-time blood pressures, respectively; for the self-measured blood pressure 135/85 mmHg might be the upper limit of normality. With regard to ABP monitoring, a large database already supports the proposed diagnostic thresholds in terms of their associations with left ventricular hypertrophy and with the incidence of cardiovascular complications; the evidence to validate the thresholds for the self-recorded blood pressure, to a large extent, must still be collected. In conclusion, the newer techniques of blood pressure measurement are now well established in the diagnosis and management of adult subjects with hypertension.

Adult↗

PubMedDate not supplied

Effects of antihypertensive treatment on endpoints in the diabetic patients randomized in the Systolic Hypertension in Europe (Syst-Eur) trial.

In this review we attempt to determine the role of calcium channel blockers in preventing cardiovascular sequela in patients with both hypertension and diabetes mellitus. The data have been collected from three sources: post hoc analyses of subgroups of diabetic patients in placebo-controlled hypertension trials (SHEP, Syst-Eur, Syst-China); a stepped care blood pressure oriented trial (HOT); and comparative trials primarily focussing on metabolic aspects and intermediate endpoints (ABCD, FACET). On balance, the data seem to indicate that long-acting calcium channel blockers score remarkably well in preventing cardiovascular complications in diabetic hypertensive patients.

Antihypertensive Agents↗

PubMedDate not supplied

[Syst-Eur study: analysis of the benefits of nitrendipine in hypertensive type 2 diabetics].

OBJECTIVE: To demonstrate that nitrendipine reduces the morbimortality of elderly type 2 diabetic patients with isolated systolic hypertension. METHODOLOGY: New analyses of the 547 type 2 diabetics patients with isolated systolic hypertension (160 < PAS < 219: PAD < 95 mmHg), included in the international Syst-Eur trial, with an average follow-up of 2 years. Type 2 diabetes is defined according to the 1998 WHO guidelines: a fasting glycemia level, > or = 126 mg/dl and a post-prandial glycemia > or = 200 mg/dl. RESULTS: Nitrendipine as a first line treatment provides better protection against fatal and no fatal cardiovascular events compared with placebo. The risk reduction of cardiovascular mortality is 70% (IC 95%: -89/-18; p = 0.01), 61% (IC 95%: -79/-29; p = 0.001) for fatal and non fatal cardiovascular events, 65% (IC 95%: -86/-10; p = 0.02) for fatal and non fatal stroke and 61% (IC 95%: -83/-11; p = 0.02) for fatal and non fatal cardiac events. Therefore, nitrendipine as a first line treatment, reduces significantly cardiovascular events, strokes and cardiac events (p = 0.02; p = 0.007; p = 0.009; p = 0.04, respectively) in the diabetic group versus the no diabetic group, with a big trend (p = 0.07) for total mortality. Nitrendipine was well tolerated by this population. CONCLUSION: These results demonstrate the benefits of nitrendipine as a first line treatment in type 2 diabetic hypertensive patients.

Antihypertensive Agents↗

PubMedDate not supplied

Lead exposure and conventional and ambulatory blood pressure: a prospective population study. PheeCad Investigators.

OBJECTIVE: - To evaluate in a prospective fashion the association between low-level lead exposure and blood pressure. DESIGN: - Prospective cohort study. SETTING: - General population. PARTICIPANTS: - A random population sample (N=728; 49% men; age range, 20-82 years) was studied in Belgium for 1985 through 1989 and reexamined for 1991 through 1995. MEAN OUTCOME MEASURES: - At baseline and follow-up, blood pressure was measured by conventional sphygmomanometry (15 total readings) and at follow-up also by 24-hour ambulatory monitoring. Lead exposure was estimated from blood lead and zinc protoporphyrin concentrations. Multivariate analyses controlled for sex, age, body mass index, smoking and drinking habits, physical activity, exposure at work, social class, menopausal status, use of medications (antihypertensive medication, oral contraceptives, hormonal replacement therapy), hematocrit or hemoglobin, serum total calcium concentration, 24-hour urinary sodium and potassium excretion, and gamma-glutamyltransferase activity. RESULTS: - At baseline, mean (SD) systolic/diastolic conventional blood pressure was 130 (17)/77 (9) mm Hg. The mean blood lead concentration was 0.42 micromol/L (8.7 microgram/dL), and the mean zinc protoporphyrin concentration was 1.0 microgram per gram of hemoglobin. Over the 5.2-year median follow-up, the mean blood lead concentration dropped by 32% (0.14 micromol/L [2.9 microgram/dL]) (P<.001). Small but significant (P<.01) changes occurred in systolic (-1.5 mm Hg) and diastolic (+1.7 mm Hg) conventional blood pressure and in zinc protoporphyrin concentration (+0.5 microgram per gram of hemoglobin). Over the follow-up period, no consistent associations emerged between the changes in conventional blood pressure and in blood lead or zinc protoporphyrin concentrations. In addition, after adjustment for sex, age, and body mass index, blood lead and zinc protoporphyrin concentrations at baseline did not predict the development of hypertension in 47 patients (risk ratio for doubling of the initial lead concentration, 1.2; 95% confidence interval, 0.7-2.0). In a time-integrated analysis in which each person was characterized by all available measurements, conventional blood pressure did not correlate with blood lead or zinc protoporphyrin concentrations in a consistent manner. Similarly, the mean (SD) 24-hour blood pressure at follow-up (119 [11]/71 [8] mm Hg; N=684) did not show a consistent relationship with blood lead or zinc protoporphyrin concentrations at baseline or at follow-up. CONCLUSIONS: - Lead exposure at the intensity studied (<l.45 micromol/L [<30 microgram/dL]) was not consistently associated with increased conventional or 24-hour blood pressure in the general population or with increased risk of hypertension. These findings argue against the hypothesis that current lead exposure levels are associated with excess cardiovascular morbidity and mortality caused by hypertension.

Adult↗

PubMedDate not supplied

Genetic variability in the renin-angiotensin system: prevalence of alleles and genotypes.

BACKGROUND: Variants of the human genes coding for renin, angiotensin-converting enzyme (ACE), angiotensinogen (AGT) and the angiotensin II type-I receptor (AT1R) are inconsistently associated with cardiovascular-renal disease, possibly because of genetic differences in the background populations. METHODS: This systematic review of the literature investigated genetic variation in the renin system according to race, sex and age. Across studies with relevant information, multivariate analyses also accounted for the methods of genotyping and the enrollment of subjects as controls, cases or groups studied cross-sectionally. RESULTS: The 185 reviewed reports included 64978 subjects. In five studies (n=989) on the renin gene, the Hind III and Taq I polymorphisms varied with the groups' average age, whereas the Bg I, Bg II and Hind III but not Taq I sites differed according to race. Among 135 studies (n=44697) on the deletion/insertion (D/I) polymorphism of the ACE gene, the frequency of the D allele was 54.0%. Its prevalence was not related to sex and black race, was 49.9% lower in Asians, 10.0% lower in studies relying on I-specific primers, 4.9% higher for each 25-year increment in the average age of the groups studied, and 16.7% higher in cases than controls. Among 12 studies (n=4952) on the T174-->M variant of the AGT gene, the M174 frequency was 11.0%, did not vary according to sex and enrollment group, was 56.7% lower in blacks and 39.5% lower for each 25-year increase in the groups' mean age. Across 44 studies (n=16713) on the M235-->T substitution in the AGT gene, the T235 prevalence was 51.6%. Its frequency was not related to sex and the method of genotyping, tended to be 7.5% lower for each 25-year increase in average age, was from 4.6 to 6.6 times higher in nonwhites than whites and 13.2% higher in cases than controls. Among 13 studies (n=4332) on the A1166-->C variant of the AT1R gene, the C1166 allelic frequency was 25.7%. Its prevalence was independent of the enrollment group, 77.4% lower in Asians, and nearly doubled for each 25-year increment in age. CONCLUSION: With adjustments applied for the subjects' enrollment group and the methods of genotyping, genetic polymorphism in the renin system varies according to race and age, but not sex. One possible application of the present results is to provide allelic and genotypic frequencies, which could be used to assess power, to perform sample size calculations, or to predict selection bias in future studies.

Age Factors↗