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Biomedical subjects

A Zanchetti

Publications and source records attributed to A Zanchetti.

At least 55 records · Page 3Linked to original sources
PubMed2001

High prevalence of cardiac and extracardiac target organ damage in refractory hypertension.

OBJECTIVE: Target organ damage (TOD) in chronically treated hypertensives is related to effective blood pressure (BP) control. The aim of this study was to evaluate the prevalence of cardiac and extracardiac TOD in patients with refractory hypertension (RH) compared with well-controlled treated hypertensives (C). METHODS: Fifty-four consecutive patients with RH (57 +/- 10 years), selected according to WHO/ISH guidelines definition, and 51 essential hypertensives (55 +/- 10 years) with satisfactory BP control obtained by association therapy, underwent the following procedures: (1) clinic BP measurement; (2) blood sampling for routine chemistry examinations; (3) 24 h urine collection for microalbuminuria; (4) non-mydriatic retinography; (5) echocardiogram; (6) carotid ultrasonogram. In order to exclude 'office resistance' (defined as clinic BP > 140/90 mmHg and average 24 h BP </= 125/79 mmHg), all patients with RH were subjected to 24-hour ambulatory BP monitoring. RESULTS: Both groups were similar for age, gender, body surface area, smoking habit and duration of hypertension, glucose, creatinine and lipid levels. By definition, clinic BP was significantly higher in RH than C (161 +/- 19/96 +/- 9 versus 127 +/- 6/80 +/- 5 mmHg, respectively, P < 0.01). The increased prevalence of left ventricular hypertrophy (LVH) and carotid intima-media (IM) thickening (40 versus 12%, P < 0.01, according to a non-gender-specific partition value of 125 g/m2; and 36 versus 14%, P < 0.01, according to IM thickness > or =1.0 mm, respectively); a higher prevalence of carotid plaques (65 versus 32%, P < 0.05), a more advanced retinal involvement (grade II and III, 73 and 5% versus 38 and 0%, P < 0.01) and a greater albumin urinary excretion (22 +/- 32 mg/24 h versus 11 +/- 13 mg/24 h, P < 0.01) were found in RH compared to C. CONCLUSIONS: Our study suggests that RH is a clinical condition associated with a high prevalence of TOD at cardiac, macro- and microvascular level and consequently with high absolute cardiovascular risk, which needs a particularly intensive therapeutic approach aimed to normalize BP levels and to induce TOD regression.

Albuminuria↗
PubMed2001

Efficacy, tolerability, and impact on quality of life of long-term treatment with manidipine or amlodipine in patients with essential hypertension.

This double-blind, multicenter trial compared antihypertensive efficacy, tolerability, and impact on quality of life of manidipine and amlodipine in patients with mild-to-moderate essential hypertension. Patients were randomly assigned to 48 weeks of once-daily manidipine, 10-20 mg, or amlodipine, 5-10 mg. Patients who did not respond to treatment after 12 weeks were also given enalapril, 10-20 mg, for the study's duration. The main efficacy end point was equivalence in sitting systolic (SiSBP) and diastolic (SiDBP) blood pressure reduction between the two drugs after 8 weeks (per protocol analysis). An intention-to-treat (ITT) analysis was performed in all patients with at least one efficacy determination during treatment. Quality of life was assessed by the "Subjective Symptoms Assessment Profile" (SSA-P) and "General Well-being Schedule" (GWBS), after 12 weeks of treatment. SiSBP reduction after 8 weeks was equivalent for manidipine (15.2 mm Hg, n = 227) and amlodipine (17.0 mm Hg, n = 219). The corresponding figure for SiDBP was 11.3 mm Hg for manidipine and 12.3 mm Hg for amlodipine. In the larger ITT population SiDBP was similarly and significantly reduced by manidipine (from 102 +/- 5 to 88 +/- 9 mm Hg, n = 241) and amlodipine (from 101 +/- 5 to 87 +/- 8 mm Hg, n = 240). Similar results were observed for SiSBP and standing SBP and DBP. Neither drug changed sitting or standing heart rate compared with baseline. SSA-P scores improved with manidipine but not amlodipine. GWBS total and partial scores increased more with manidipine than with amlodipine. Safety profile favored manidipine, which was associated with significantly less ankle edema than was amlodipine. This study shows for the first time that long-term treatment with the long-acting calcium channel blocker manidipine is as effective as treatment with amlodipine, has a better tolerability profile, and induces greater improvement in quality of life than amlodipine.

Adult↗
PubMed2001

Serum uric acid for short-term prediction of cardiovascular disease incidence in the Gubbio population Study.

OBJECTIVE: The Gubbio Study is an Italian population study measuring risk factors for and incidence of major cardiovascular diseases. This analysis investigates the association of serum uric acid with the incidence of coronary and cardiovascular events. METHODS: A population sample of 2469 men and women aged 35-74 years, free from major cardiovascular diseases and in whom serum uric acid was measured in 1983 along with other standard risk factors, were followed up for 6 years and the incidence of coronary heart disease (CHD) and all cardiovascular atherosclerotic (CVD) events, both fatal and non-fatal, was computed. Proportional hazards models were used for the prediction of these events. RESULTS: In six years 61 CHD hard criteria, 109 CHD any criterion and 149 CVD events were recorded. Age-adjusted rates per 1000 of the 3 event categories were computed in sex-specific quintiles (Q) of serum uric acid with 428 +/- 76 (Q5) and 198 +/- 42 (Q1) micromol/l, respectively. Although higher rates were seen in Q5 as compared to Q1 for all three first event categories considered (relative risks 6.2, 3.6 and 3.7, respectively), a statistically significant trend was seen only for CVD all criteria (t = 3.63, p < 0.036). These trends were borderline significant for CHD any criterion (t = 2.92, p < 0.06) and not significant for CHD hard criteria (t = 2.23, p < 0.11). In multivariate models, adjusted for 8 other risk factors, serum uric acid showed a statistically significant contribution to predict CVD incidence [relative risk (RR) for 92 micromol/l difference of 1.24 with 95% confidence intervals (CI) 1.05-1.45], whereas the statistical contribution to predict CHD any criterion (RR = 1.19 with CI 0.98-1.45) and CHD hard criteria (RR = 1.20 with CI 0.93-1.55) was not significant. Diuretic treatment and blood urea, as further confounders, were positively and significantly related to event incidence (RR ranging from 1.21 to 2.00) but serum uric acid maintained its independent and statistically significant role in the prediction of CVD events (RR = 1.18 with CI 1.00-1.39). Presence of specific treatments to lower serum uric acid levels (in 1.13% of the population), tested as final confounders, was not statistically contributory. CONCLUSIONS: Increased serum uric acid levels are independently and significantly associated with risk of CVD events in the 6-year follow-up of the Gubbio Study. Longer follow-up is needed before the contributory role of serum uric acid can be properly assessed to explain CHD incidence.

Adult↗
PubMed2001

Evaluation of target organ damage in arterial hypertension: which role for qualitative funduscopic examination?

BACKGROUND: The objective of this study was to compare the prevalence of quantitative markers of target organ damage, such as echocardiographically documented left ventricular hypertrophy (LVH), carotid structural changes and microalbuminuria with that of retinal abnormalities detected by qualitative funduscopic examination in a large selected population of patients with essential hypertension. METHODS: Eight hundred consecutive untreated (n = 232) and treated (n = 568) hypertensive patients (386 men, 414 women, mean age 52.7 +/- 11.8 years) referred for the first time to our out-patient clinic were included in the study. In order to search for target organ damage, they were submitted to the following procedures: 1) amydriatic retinography, 2) 24-hour urine collection for microalbuminuria, 3) echocardiography, and 4) carotid ultrasonography. Retinal changes were evaluated according to the Keith, Wagener and Barker (KWB) classification by two physicians, who had no knowledge of the patients' characteristics. Microalbuminuria was defined as a urinary albumin excretion > 30 and < 300 mg/24 hours, LVH as a left ventricular mass index > or = 134 g/m2 in men and > or = 110 g/m2 in women; finally carotid plaque was defined as a focal thickening > 1.3 mm. RESULTS: Hypertensive retinopathy was the most frequent (KWB grade I 46%, II 32%, III-IV < 2%) marker of target organ damage, followed by carotid plaques (43%), LVH (22 %, eccentric LVH was the prevalent type and was 1.8 times as frequent as the concentric one) and microalbuminuria (14%). CONCLUSIONS: At variance with the markers of cardiac, macrovascular and renal damage, an extremely high prevalence of retinal abnormalities (narrowings and initial arterio-venous crossings) were found in our population. If, as suggested by the WHO/ISH guidelines, these retinal abnormalities were considered as a reliable marker of target organ damage, then almost all patients would be affected by hypertensive vascular disease. Based on this evidence it is suggested that retinal abnormalities included in funduscopic grades I and II of the KWB classification should not be considered among the criteria for the quantitative detection of target organ damage.

Adult↗
PubMed2000

Sympathoexcitatory responses to the acute blood pressure fall induced by central or peripheral antihypertensive drugs.

This study was designed to evaluate the effects of an acute blood pressure reduction brought about by a peripheral vasodilator agent (prazosin) or by a drug combining central and peripheral modes of action (urapidil), on three markers of adrenergic tone such as muscle sympathetic nerve traffic (MSNA), venous plasma norepinephrine (NE), and heart rate (HR). In 12 untreated essential hypertensives (age, 50.7 +/- 1.9 years; mean +/- SEM), we evaluated in two experimental sessions, according to a double-blind crossover design, the effects of acute oral administration of 2 mg prazosin or 30 mg urapidil on beat-to-beat finger blood pressure (Finapres), HR (electrocardiogram), NE (high-performance liquid chromatography), and MSNA (microneurography at a peroneal nerve). In each session measurements were performed in the no-drug control state and repeated throughout a 3-h period after drug administration. For similar blood pressure reductions, the two drugs caused similar increases in NE and MSNA (peak effects: NE = +1.1 +/- 0.2 vs 0.9 +/- 0.2 nmol/L and MSNA = +10.9 +/- 1.8 vs +10.1 +/- 1.6 bursts/min for prazosin and urapidil respectively, P = ns between drugs), whereas HR increased more markedly after prazosin administration (+6.1 +/- 1.1 vs +2.4 +/- 0.8 beats/min, P < 0.05). These data provide evidence that acute blood pressure reductions induced by antihypertensive drugs with central or peripheral modes of action activate the sympathetic nervous system to a similar extent. Thus adrenergic activation is not peculiar to vasodilators but rather generalized to any drug-induced acute blood pressure fall, presumably because of the lack of a baroreflex resetting, which occurs during chronic but not during acute antihypertensive treatment.

Adult↗
PubMed2000

Pulse pressure and isolated systolic hypertension: association with microalbuminuria. The GUBBIO Study Collaborative Research Group.

BACKGROUND: The long-term risk of end-stage renal disease is high in persons with isolated systolic hypertension, that is, those with an elevation of pulse pressure and not of diastolic pressure. Other data suggest that pulse pressure is a predictor of the hypertension-induced organ damage. Microalbuminuria is considered an early sign of glomerular damage caused by hypertension. The study shows the relationship of pulse pressure and isolated systolic hypertension to microalbuminuria in nondiabetic subjects. METHODS: This is a cross sectional analysis for a population sample of 677 men and 890 women, aged 45 to 64 years, who were without diabetes mellitus and macroalbuminuria. Data collection included: overnight urinary albumin and creatinine excretion; fasting plasma glucose, cholesterol, and creatinine; creatinine clearance; and blood pressure, weight, height, medical history, and smoking habit. Pulse pressure was calculated as systolic minus diastolic pressure. Isolated systolic hypertension was defined as systolic pressure > or =140 mm Hg in persons not on antihypertensive drugs and with diastolic pressure <90 mm Hg. Microalbuminuria was defined as urinary albumin excretion > or =20 microg/min. RESULTS: Pulse pressure and isolated systolic hypertension were significantly related to urinary albumin excretion and the prevalence of microalbuminuria in univariate and multivariate analyses. Controlling for gender and other variables, the risk of microalbuminuria was 1.71 with a 15 mm Hg higher pulse pressure (95% CI, 1.31 to 2.22) and 4.95 in the presence of isolated systolic hypertension (95% CI, 3.15 to 7.76). CONCLUSIONS: In nondiabetic, middle-aged adults, pulse pressure and isolated systolic hypertension are directly related to microalbuminuria, independent of diastolic pressure and other correlates.

Age Distribution↗
PubMed2000

"To better know hypertension": educational meetings for hypertensive patients.

BACKGROUND: Pilot educational meetings were conducted to (1) verify the support of hypertensive patients in this initiative; (2) test the knowledge of patients regularly followed-up in our Hypertension Centre Outpatient Clinic concerning problems related to hypertension; (3) improve patients knowledge about hypertension through a formal teaching session, (4) compare the knowledge of these patients with that of a control group. METHODS: An invitation to participate in an educational program on hypertension was extended to 210 consecutive patients (group I ) followed-up in the outpatient clinic of our Hypertension Centre. Each meeting included four sessions: (1) an interactive phase with electronic devices aimed at evaluating the degree of information about hypertension by means of multiple-choice questionnaires, (2) a traditional teaching session, (3) an interactive phase to assess the compliance to treatment, and (4) a general discussion session. The control group (II) included 144 hypertensive patients referred for the first time to our Hypertension Centre. Before the initial visit the patients were asked to answer a questionnaire identical to that provided to group I during the meetings. RESULTS: The meetings were attended by 183 out of the 210 patients in group I (participation rate = 87%). The answers to the questions were corrected as a percentage ranging from 73.7 to 95.6 in group I and from 43.9 to 74.7 in group II (p < 0.01). The provision of more detailed information about problems in hypertension was associated with better compliance to treatment and blood pressure control. (BP under treatment 138 +/- 14/83 +/- 7 mmHg in group I, 152 +/- 15/91 +/- 11 mmHg in group II; (p < 0.01). CONCLUSIONS: Our data indicate that this type of educational approach is appreciated by patients (participation rate 87%) and that the level of knowledge about hypertension and compliance to treatment are greater in selected patients than in control patients.

Aged↗
PubMed2000

Baseline reproducibility of B-mode ultrasonic measurement of carotid artery intima-media thickness: the European Lacidipine Study on Atherosclerosis (ELSA).

BACKGROUND AND OBJECTIVE: The European Lacidipine Study of Atherosclerosis (ELSA) is a prospective, randomized, double-blind, multi-national interventional trial to determine the effect of four-year treatment using the calcium antagonist lacidipine versus the beta-blocker atenolol on the progression of carotid atherosclerosis in 2259 asymptomatic hypertensive patients. B-mode ultrasound is used to measure the primary and secondary endpoints including the mean maximum intima-media thickness (IMT) of the carotid bifurcations and the common carotid arteries (CBM(max)), the mean maximum IMT of 12 standard carotid sites (M(max)) and the overall maximum IMT (T(max)). This paper reports the cross-sectional reproducibility of ultrasound measurements at baseline. METHOD: To evaluate measurement reliability, each patient is scanned twice at baseline and again at four annual visits, with 80% of the replicate scans performed by the same sonographer and 20% by a different sonographer; 50% of the replicate scans are read by the same reader and the other 50% by different readers. RESULTS: The overall coefficient of reliability (R) was 0.859 for CBM(max), 0.872 for M(max) and 0.794 for T(max). The reliability for CBM(max) was stable during the 1 3/4-year baseline period (R = 0.848 to 0.953) and was uniform among the 23 field centres (R = 0.798 to 0.926). Intra- and inter-reader reliability were 0.915 and 0.872 respectively, and intra-sonographer reliability was 0.866. CONCLUSION: The results demonstrate that by implementing standardized protocols and strict quality control procedures, highly reliable ultrasonic measurements of carotid artery IMT can be achieved in large multi-national trials.

Adrenergic beta-Antagonists↗
PubMed2000

Influence of gender and age on preventing cardiovascular disease by antihypertensive treatment and acetylsalicylic acid. The HOT study. Hypertension Optimal Treatment.

OBJECTIVE: We have assessed the influence of gender and age on the main outcome results of the Hypertension Optimal Treatment (HOT) study. DESIGN AND INTERVENTIONS: The aims of the HOT study were to study the relationship between three levels of target office diastolic blood pressure (BP) (< or = 90, < or = 85 or < or = 80 mmHg) and cardiovascular (CV) events in hypertensive patients, and to examine the effects of 75 mg acetylsalicylic acid (ASA) daily versus placebo. SETTING: Outpatient clinical trial in 26 countries. PATIENTS: A total of 18790 patients (mean age 61.5 years, range 50-80) were randomized and followed for an average of 3.8 years until 71051 patient-years and 683 events had occurred. MAIN OUTCOME MEASURES: CV death, myocardial infarction (MI) and stroke. RESULTS: There were significantly fewer MIs in those in the lower diastolic BP target groups (3.0 versus 1.2 and 1.7 MIs/1000 patient-years, P for trend = 0.034) in women (n = 8883), whereas the similar but smaller trend (4.1 versus 4.1 and 3.4 MIs/1000 patient-years) was not statistically significant in men nor in the subgroup analysis of younger and older subjects. The effect of ASA on preventing MI was not influenced by age < 65 years (P= 0.02) or age > or = 65 years (P = 0.04) but was influenced by gender (P = 0.38 in women and P = 0.001 in men, lowered by 42% corresponding to a reduction from 5.0 to 2.9 MIs/1000 patient-years). CONCLUSIONS: The data of this HOT study sub-analysis suggest somewhat differentiated optimal gender- and age-dependent effects of anti-hypertensive and anti-platelet therapies; lowering of diastolic BP to about 80 mmHg in hypertensive women and, in addition, the administration of 75 mg of ASA to well-treated hypertensive men appear to effectively reduce the most common cardiovascular complication, i.e. myocardial infarction, in patients with essential hypertension.

Age Factors↗
PubMed2000

Prevalence of target organ damage in treated hypertensive patients: different impact of clinic and ambulatory blood pressure control.

OBJECTIVES: First, to evaluate the prevalence of left ventricular (LV) hypertrophy, LV concentric remodelling and microalbuminuria in a selected sample of treated hypertensive patients with effective and prolonged clinic blood pressure (BP) control (BP < 140/90 mmHg). Second, to compare the prevalence of these markers of organ damage in patients with and without ambulatory BP (ABP) control, defined as average daytime BP < 132/85 mmHg). DESIGN AND METHODS: Fifty-eight consecutive hypertensive patients who attended our hypertension outpatient clinic over a period of 3 months and were regularly followed up by the same medical team were included in the study. Obesity, diabetes mellitus, history or signs of cardiovascular or renal complications and major noncardiovascular diseases were the exclusion criteria from the study. Each patient underwent 24 h ABP monitoring, echocardiography and 24 h urine collection for albumin measurement. RESULTS: The prevalence of LV hypertrophy (LV mass index > 125 g/m2 in both sexes), LV concentric remodelling (relative wall thickness > 0.45) and microalbuminuria (urinary albumin excretion < 300 mg/ 24 h) in this selected group of patients (32 men, 26 women; mean age 53 +/- 9 years; mean clinic BP 122 +/- 9/ 78 +/- 6 mmHg) was markedly low (6.9, 8.6 and 5.1%, respectively). The 26 patients with effective ABP control (group I) were similar to the 32 patients without effective ABP control (group II) in age, gender, body surface area, clinic BP, smoking habit, glucose, cholesterol and creatinine plasma levels. Prevalence of LV hypertrophy, LV concentric remodelling and microalbuminuria was lower in group I than in group II (0 versus 12.9% P< 0.01, 7.7 versus 9.4% NS, 3.8 versus 6.2% NS, respectively). CONCLUSIONS: This study demonstrates that nonobese, nondiabetic hypertensive patients with an effective clinic BP control have a very low prevalence of target organ damage and that LVH is present only in individuals with insufficient ABP control.

Albuminuria↗
PubMed2000

Effects of a reversible 'nephrectomy' on renal sympathetic activity and blood pressure in the rat: evidence for an acute angiotensin-mediated hypertension.

OBJECTIVE: To verify whether the normal kidney exerts a supportive, facilitatory action on renal sympathetic nerve activity (RSNA), the effects of unilateral and bilateral nephrectomy on RSNA have been studied. METHODS: The RSNA, rectal temperature (T), rate of breathing (RB), arterial blood pressure (BP) and heart rate (HR) were continuously recorded in three groups of pentobarbital anaesthetized, spontaneously breathing Sprague-Dawley rats: group 1 (n = 5): both kidneys intact; group 2 (n = 5): left surgical nephrectomy; group 3 (n = 5): left surgical nephrectomy and functional exclusion of the right kidney (functional right nephrectomy, FRN), produced by a tight ligature of the renal hilum which was maintained for 3 h. In a fourth group (n = 7), in which nerve activity was not recorded, reopening of the right renal hilum was preceded or followed by intravenous administration of captopril (3 mg/kg). RESULTS: In groups 1 and 2 RSNA increased from 22.3 +/- 2.1 to 122.9 +/- 13.6 and from 26.7 +/- 1.2 to 93.2 +/- 14.0 impulses/s (mean +/- SEM), respectively, without concomitant changes in cardiovascular parameters. In group 3 RSNA decreased from 39.1 +/- 3.1 to 13.7 +/- 2.6 impulses/s during the 3 h of FRN. In group 3 the reopening of the right renal hilum was followed by a marked increase in BP and HR that was prevented or reversed by intravenous captopril in rats of group 4. CONCLUSIONS: The decrease in RSNA observed in rats during bilateral nephrectomy, in contrast to the increase observed in rats with one or both kidneys intact, suggests that the kidney as a whole exerts a supportive role on sympathetic nerve activity. The hypertension and tachycardia that follows the reopening of the right kidney hilum appears to be caused by the generation of endogenous angiotensin II; this is the first evidence of an acute angiotensin-mediated renal hypertension.

Acute Disease↗
PubMed2000

Patterns of hypertension management in Italy: results of a pharmacoepidemiological survey on antihypertensive therapy. Scientific Committee of the Italian Pharmacoepidemiological Survey on Antihypertensive Therapy.

OBJECTIVE: To collect statistically significant information on patterns of antihypertensive therapy in medical practice, with particular attention to the drugs used in the pharmacological management of hypertensive patients and the reasons for the limited achievement of therapeutic goals during treatment DESIGN: A survey conducted among general practitioners, specialists, and hypertensive patients. METHODS: A total of 28,000 physicians were contacted by letter and 3,394 declared their willingness to participate and received a questionnaire. Subsequently, 1,255 questionnaires suitable for analysis (corresponding to 37.0% of adhering physicians) were received. In addition, 4,612 questionnaires completed by patients were pooled and evaluated. The prevalence of hypertension was calculated from a base of 254,192 patients, seen by general practitioners. RESULTS: The prevalence of hypertension, defined as systolic blood pressure > or = 160 mmHg or diastolic blood pressure > or = 95 mmHg, or current treatment, was 19.7%. The average number of hypertensive patients in each general practitioner's file, covering the previous 12 months, was approximately 230. Physicians reported a 66% rate of discontinuation of treatment or switching to another drug. Physicians and patients both considered inadequate blood pressure control and side effects to be the two main reasons for switching antihypertensive therapy, but in opposite order. Furthermore, physicians indicated a prevalence of drug side effects between 10 and 20%, according to class of drug used, whereas 69% of patients reported to have experienced side effects. In the doctors' opinions, there were many reasons for poor patient adherence: complexity of the drug regimen, appearance of side effects, forgetfulness, reduced patient understanding of the need for long-term continuation of treatment, and refusal to accept a chronic pathological condition. CONCLUSIONS: The survey showed awareness of the disease among physicians and provides a representation of the experiences of both general practitioners and specialists, in addition to that of their patients. During antihypertensive therapy, a disconcerting degree of discontinuation and switching of drugs occurred. Insufficient blood pressure control and side effects accounted for most of the observed treatment changes. This survey revealed the existence of a gap between the physicians' perception of tolerability and the real experience of patients, a clear need for greater tolerability of treatments, and a need for an enhancement of patient-physician communication.

Antihypertensive Agents↗
PubMed2000

Effects of adenosine receptor agonists on efferent renal nerve activity in anesthetized rats.

The aim of this study was to investigate the effects of A1 and A2 adenosine-receptor activation on the sympathetic nervous system. The effects on efferent renal nerve activity of selective A1 (CCPA; 2-chloro-N-6-cyclopentyladenosine) and A2 (2HE-NECA; 2-hexynyl-5'-N-ethylcarboxamidoadenosine) adenosine-receptor agonists were studied in anesthetized rats either with intact baroreflexes (intact rats) or with bilateral sinoaortic denervation and vagotomy (denervated rats). After a control period of 5 min, A1 or A2 agonist or vehicle were intravenously infused for 8 min in separate groups of intact or denervated rats, in which arterial pressure and heart rate were continuously recorded. CCPA (5.0 microg/kg/min) and 2HE-NECA (0.7 microg/kg/min) were selected to obtain comparable blood pressure changes over the period of observation. Arterial pressure significantly and equally decreased during the A1 (-41 +/- 8%), and A2 (-35 +/- 5%) agonist administration. Heart rate significantly decreased during A1 agonist infusion, but it did not change during A2 agonist administration. Bilateral sinoaortic denervation and vagotomy did not modify the hemodynamic responses to both drugs. The A1 and A2 administration caused a large and significant increase in efferent renal nerve activity (+66 +/- 22% and +76 +/- 15%, respectively), and this effect was entirely abolished in denervated rats. A linear relation with a significant negative slope between changes in arterial pressure and changes in neural discharge was observed for each treatment. The comparison of the regression slopes showed that the reflex increase of efferent sympathetic activity caused by the administration of both agonists was significantly smaller than the increment induced by equipotent hypotensive dose of sodium nitroprusside (10 microg/kg). These data show that the selective activation of A1 and A2 receptors elicits a reflex increase in efferent renal nerve activity. This neural activation is smaller as compared with the effect of equihypotensive doses of sodium nitroprusside, thus indicating a blunting effect of both adenosine agonists on baroreceptor sensitivity.

Adenosine↗
PubMed2000

Antihypertensive efficacy of manidipine and enalapril in hypertensive diabetic patients.

Recent studies showed that in diabetic hypertensive patients, administration of angiotensin-converting enzyme (ACE)-inhibitors or calcium antagonists can effectively lower blood pressure (BP) and prevent diabetes-related cardiovascular complications with no adverse metabolic effects. We sought to assess the antihypertensive and metabolic effects of the new dihydropyridine calcium antagonist manidipine (M) in patients with diabetes mellitus and essential hypertension as compared with the ACE inhibitor enalapril (E). After 3 weeks of placebo, 101 (62 men; age range, 34-72 years) hypertensives with type II diabetes mellitus were randomized to M 10-20 mg or E 10-20 mg, od, for 24 weeks. At the end of the placebo period and the active-treatment phase, BP was measured with a mercury sphygmomanometer (office, O) and over the 24 h by ambulatory (A) monitoring. ABP recordings were analyzed to obtain 24-h, day (6 a.m. to midnight), and night (midnight to 6 a.m.) average systolic (S) and diastolic (D) BP and heart rate (HR) values. Homogeneity of the antihypertensive effect over the 24 h was assessed by the smoothness index [SI: i.e., the ratio between the average of the 24 hourly BP changes after treatment and the corresponding standard deviation (the higher the SI, the more uniform is the BP control by treatment over the 24 h]. The O SBP and DBP were significantly (p < 0.01) and similarly reduced by M (16 +/- 10 and 13 +/- 6 mm Hg, n = 49) and E (15 +/- 10 and 13 +/- 6 mm Hg, n = 45). The percentage of patients whose O DBP was reduced < or = 85 mm Hg (i.e., the value indicated to be the optimal DBP goal in diabetic hypertensives) was similar for M (37%) and E (40%). The reduction of 24-h BP also was similar between M (n = 38) and E (n = 38) for both drugs (systolic, 6 +/- 11 and 8 +/- 10 mm Hg; diastolic, 5 +/- 8 and 5 +/- 7; NS, M vs. E). The antihypertensive effect was distributed in a similar homogeneous fashion throughout the dosing interval, as shown by the similar SI values (M, 0.6 +/- 1.2 for SBP and 0.6 +/- 0.9 for DBP; E, 0.6 +/- 0.8 for SBP and 0.5 +/- 0.7 for DBP; NS, M vs. E). O and A HR were unchanged by either treatment. Markers of glucose and lipid metabolism and renal function were not significantly modified by treatment both with M and with E. In the diabetic hypertensives, M was as effective and metabolically neutral as the ACE-inhibitor E.

Adult↗
PubMed2000

Impact of blood pressure control on prevalence of left ventricular hypertrophy in treated hypertensive patients.

AIM: The aim of the present study was to evaluate (1) the prevalence and patterns of left ventricular hypertrophy (LVH) and (2) the impact of blood pressure (BP) control, assessed by clinical and 24-hour ambulatory BP monitoring (ABPM) criteria on the persistence of LVH in a representative sample of treated patients attending our Hypertension Clinic. METHODS: One hundred consecutive essential hypertensives (61 m/39 f, age 56+/- 9 years) regularly followed up by the same medical team (average period 52 months, 12-156 months) were included in the study and underwent 24-hour ABPM and complete echocardiographic examination. RESULTS: Twenty-eight of the 100 patients were found to have LVH [left ventricular mass index (LVMI) >125 g/m(2) in men and >110 g/m(2) in women]; LVH was eccentric in 20 patients and concentric in the remaining 8. LVMI did not correlate with clinical BP values but only with ABPM values (mean 24 h systolic r = 0.34, p <0.01; diastolic r = 0.37, p <0.01). The prevalence of LVH in patients controlled according to clinical BP criteria (n = 43, BP <140/90 mm Hg) was 19%, in patients controlled according to ABPM criteria (n = 30, BP during daytime <132/85 mm Hg) 17%, and in those controlled with both criteria (n = 16) 6% (p <0. 01). CONCLUSIONS: The results of this study suggest that the eccentric type of LVH is the prevalent pattern in chronically treated patients. The persistence of LVH is significantly dependent on BP levels achieved during treatment; indeed the prevalence of LVH is very low in patients with an optimal BP control, whereas it is elevated (37%) in uncontrolled patients.

Antihypertensive Agents↗