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Biomedical subjects

S Cottone

Publications and source records attributed to S Cottone.

At least 37 records · Page 2Linked to original sources
PubMed1995

Sympathetic overactivity and 24-hour blood pressure pattern in hypertensives with chronic renal failure.

In order to assess the activity of the sympathetic system and to evaluate the 24-h blood pressure pattern in hypertensives with chronic renal failure (CRF), 12 CRF patients and 16 essential hypertensives (EHs) were studied. In all subjects, plasma samples for catecholamines and renin activity were obtained both in the basal condition and after standing, and 24-h blood pressure monitoring (ABPM) was performed. The 24-h mean blood pressure results were quite similar between CRFs and EHs. In 50% of the CRFs, ABPM showed a nighttime decrease in diastolic BP (DBP) greater than 10%, while in the remaining 50% the ABPM indicated a nondipper blood pressure pattern. Of the 16 EHs, 4 had a nighttime decrease in DBP < 10%, that is, nondippers. The study of circulating catecholamines showed no significant differences in plasma epinephrine between CRFs and EHs, while plasma norepinephrine (NE) was significantly higher in hypertensives with CRF than in EHs, both at rest and after standing (p < 0.05 and 0.02, respectively). Among dipper hypertensives, subjects with CRF showed greater values of basal plasma NE than EHs (535 +/- 67 vs. 412 +/- 24.5 pg/mL, p < 0.05); the comparison between dipper and nondipper CRFs showed no differences in circulating NE levels (535 vs. 516 pg/mL). The present study shows that CRFs are characterized by higher values of plasma NE than EHs, and that there are no differences in sympathetic activity between dipper and nondipper hypertensives with CRF.

Blood Pressure↗
PubMed1995

White-coat hypertension and cardiovascular risk.

OBJECTIVE: To compare cardiovascular risk in white-coat hypertensives, normotensives and established hypertensives. METHODS: We studied 61 hypertensive individuals, 27 of whom were white-coat hypertensives, and 35 normotensives. All subjects underwent 24 h noninvasive blood pressure monitoring and Doppler echocardiographic examination of the heart; urine was tested for microalbuminuria and the fundi of the eyes examined for retinopathy. RESULTS: The 24 h as well as the day- and night-time mean systolic blood pressure (SBP) was slightly but significantly higher in white-coat hypertensives than in normotensives; no significant difference was observed in diastolic blood pressure (DBP) between these groups. In white-coat hypertensives, 24 h SBP and DBP were lower than in established hypertensives (P < 0.001). The echocardiographic study showed higher values of posterior wall thickness, left ventricular mass index (LVMI), and ventricular septum thickness (P < 0.05) in white-coat hypertensives than in normotensives; fractional shortening and ejection fraction were similar. The E:A ratio, obtained from the Doppler study, was lower in white-coat hypertensives than in normotensives (1.14 +/- 0.3 versus 1.24 +/- 0.25; P < 0.05). LVMI values were smaller in white-coat hypertensives than in established hypertensives (P < 0.05), and both ejection fraction and fractional shortening were similar in the two groups. Among white-coat hypertensives, eight out of 27 showed hypertensive retinal damage; microalbuminuria values were similar to those obtained in normotensives. CONCLUSIONS: The results of this cross-sectional and therefore limited study lead us to hypothesize that white-coat hypertensives are at higher risk than normotensives and lower risk than established hypertensives for developing cardiovascular damage.

Adult↗
PubMed1994

The renal functional reserve in recently diagnosed essential hypertension.

Recent studies have shown that both in hypertensives and in offspring of hypertensive parents there exists an altered renal functional reserve (RFR). The aim of this research was to study the RFR in newly diagnosed essential hypertensives, and to evaluate if any influences are played on RFR by circulating renin-angiotensin-aldosterone system, catecholamines, and plasma endothelin-1. In 16 essential hypertensives (EH) and in 10 healthy controls (C), on the 24-hour urine collection and on urine specimens taken after both an oral water load and an amino acids (AAs) infusion (4.16 ml/min for two hours), Ccr, microalbuminuria (AER) and its fractional clearance, and sodium excretion (Nau) were evaluated. Furthermore, both in basal condition and after the AAs load, blood samples were obtained to assay plasma renin activity (PRA) and aldosterone concentrations (PAC), circulating norepinephrine (NE) and endothelin-1 (ET-1). The C-group showed a mean increase in Ccr of 35%. No significant modifications in AER and in circulating hormones were observed. Among the 16 EH, thirteen subjects showed a significant increase in Ccr after the AAs load, with a mean increase of 32.5%. In the whole group of EH there were no significant differences in AER when comparing basal with after-load values, and Nau resulted significantly decreased after AAs infusion. The analysis of the hormonal pattern pointed out not significant changes in the behaviour of PRA, NE and ET-1, while a significant decrease in PAC was observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Screening for congenital renovascular hypoplasia and renal artery stenosis by acute converting enzyme inhibition.

To evaluate the usefulness of the captopril test for identifying renal artery stenosis (RAS) and renovascular hypoplasia (RAH), we studied 48 hypertensive patients. In 20 hypertensives with screening procedures indicating renovascular disease and in 28 essential hypertensives (EH), the plasma renin activity (PRA) responses to an oral test dose of captopril (50 mg) were studied. A 60-min post-captopril PRA increase of 150% (or 400% if baseline PRA < or = 3 ng/ml/h) was considered as positive. Renal angiography was performed in all cases. Among the 20 renovascular hypertensive patients, RAH in 9 and RAS in 11 subjects were proved by angiography. The captopril test in all patients with RAH resulted negative (mean PRA increase 50%); furthermore, the test identified 7 of the 11 RAS (mean PRA increase 477.6%); sensitivity and specificity for RAS were 64 and 88.8%, respectively. In the EH group, there were 3 false-positive subjects (mean PRA increase 122%). This study demonstrates that the PRA responses to a test dose of captopril are a useful screening test for distinguishing RAH from RAS, and for identifying the latter in hypertensive patients. These data also suggest that in subjects with RAH, hypertensive disease may not renin dependent.

Administration, Oral↗
PubMed1993

[Prevalence of microalbuminuria in recent-onset essential hypertension].

To determine the prevalence of increased microalbuminuria (AER) in essential hypertension, we studied an omogeneous population comprehensive of 160 mild-moderate essential hypertensives (EH) and 30 normotensive controls. All subjects underwent measurement of AER and creatinine clearance (CCl) on the 24-hour urine collection, and of plasma renin activity (PRA). The 24-hour mean arterial pressure (24h-BP) was also obtained by non-invasive ambulatory BP monitoring. The EH were subdivided into subgroups on the basis of their AER values (less or over 11 micrograms/min). Among the 160 EH the prevalence of high AER levels was of 37.5% (n = 60), showing in this subgroup of EH a mean value of 29.5 +/- 4 micrograms/min. Moreover, in the whole population of 160 EH, AER was significantly correlated to 24h-diastolic BP (p < 0.05). The subgroup of 60 EH with AER > 11 micrograms/min showed also Ccl values higher than the other subgroup of EH (p < 0.02), while non significant differences between age, mean duration of EH, PRA, and 24h-BP, both systolic and diastolic, were observed. Our results lead to hypothesize that in essential hypertension there exists a subgroup of subjects characterized, in the early phase of disease, by high capillary glomerular pressure, GFR and microalbuminuria values.

Adult↗
PubMed1992

Microalbuminuria fractional clearance and early renal permselectivity changes in essential hypertension.

In order to verify if, in essential hypertension (EH), the microalbuminuria (AER) increase could be due to hemodynamic modifications or to glomerular structural changes, in 15 essential hypertensives (EHs) with 24-hour AER > 16 micrograms/min and in 15 EHs with 24-hour AER < or = 16 micrograms/min, the day- and nighttime behavior of creatinine clearance (Ccr), as well as AER clearance (AER-C) and fractional clearance (AER-FC), and behavior of blood pressure (BP) was evaluated. Patients with 24-hour AER > 16 micrograms/min showed significantly higher values of 24-hour and daytime Ccr than the other group of EHs, while during the night period, there were no significant differences between the two groups. On the contrary, AER and both AER-C and AER-FC resulted markedly and significantly higher in the EHs with 24-hour AER > 16 micrograms/min not only in the 24-hour evaluation, but also during the nighttime study, notwithstanding the significant decrease in BP and in Ccr observed during the night. These data, in the absence of correlations between BP and AER-FC seem to demonstrate the existence in EHs with 24-hour AER > 16 micrograms/min of an altered glomerular permselectivity, due to changes of the glomerular membrane.

Adult↗
PubMed1991

Blood pressure pattern importance in the development of left ventricular hypertrophy in hypertension.

Heterogeneous results regarding correlations between blood pressure, (measured by various methods and in different conditions), and left ventricular mass in arterial hypertension have been reported. Fifty-three essential hypertensives, I-II WHO stage, have been studied in order to verify the relationship between office and average 24-hour blood pressure, and its day- and night-time pattern with left ventricular hypertrophy. All patients had newly diagnosed essential hypertension, and no subject had received any antihypertensive therapy before entry. The subjects underwent 24-hour blood pressure monitoring, evaluating the average of 24 hours, day- and night-time blood pressures, and M-mode echocardiography. Neither subjects with nor without left ventricular hypertrophy showed correlations between office blood pressure and left ventricular mass. On the contrary, average 24-hour systolic and diastolic blood pressure resulted related to left ventricular mass (r = 0.36 and 0.40, p less than 0.01 respectively). Furthermore, in the subgroup with left ventricular hypertrophy, left ventricular mass was correlated directly with nocturnal systolic blood pressure (r = 0.46) and inversely with the rate of nocturnal decrease in systolic pressure (r = -0.60, p less than 0.01). These results appear to confirm the usefulness of 24-hour blood pressure monitoring in evaluating cardiac afterload in essential hypertension, and the important role that the 24-hour systolic pressure has in the development of left ventricular hypertrophy in these subjects.

Adult↗
PubMed1990

Reversal of cardiac hypertrophy and left ventricular function with the calcium antagonist felodipine in hypertensive patients.

A study was carried out to evaluate the influence of antihypertensive treatment with a calcium antagonist on left ventricular hypertrophy and to estimate left ventricular performance after reversal of myocardial hypertrophy. Ten essential hypertensives (age 45 +/- 2 years; WHO class II) underwent an M-mode echocardiogram guided by two-dimensional echocardiography, during a wash-out period and after 3, 6 and 12 months of treatment with felodipine ER 10 mg/daily. At month 12 the echocardiogram was also performed during a handgrip test. BP levels during the treatment period decreased significantly, and left ventricular mass index showed a significant reduction from 143 +/- 13 to 112 +/- 9 g/m2 (P less than 0.001). A significant increase occurred in fractional shortening (FS) which was associated with decreases in end-systolic stress (ESS), left ventricular internal diameter (LVIDs) and inotropic state indices. Moreover, after reversal of myocardial hypertrophy left ventricular performance remained unchanged. Linear regression analysis showed a significant correlation of FS with ESS, which remained significant until the end of the study period, both at rest and at peak handgrip test (r = -0.68; P less than 0.05 and r = -0.80, P less than 0.01 respectively). This study demonstrates a significant decrease in left ventricular mass during treatment with a dihydrophyridine calcium antagonist and a good maintenance of left ventricular performance following reversal of myocardial hypertrophy in hypertensives.

Adult↗
PubMed1990

[Usefulness of captopril test in diagnosis of renal artery stenosis and congenital small kidney in arterial hypertension].

We studied 45 hypertensive subjects to evaluate the usefulness of captopril test for identifying renal artery stenosis and small congenital kidney with the hypoplasia of the renal artery. In 18 hypertensives with hippuran renogram indicating renovascular disease, and in 27 essential hypertensives, the plasma renin activity (PRA) responses to an oral test dose (50 mg) of captopril were studied. A 60-minute post captopril PRA increase of 150% (or 400% if baseline PRA less than 3 ng/ml/h) was considered as positive. Digital venous angiography was performed in all cases. In the group of 18 subjects small congenital kidney in 7, and renal artery stenosis in 11 subjects were detected by angiography. Captopril test resulted negative in all patients with small congenital kidney (mean PRA% increase 58). The test identified 7 of the 11 renal artery stenoses (mean PRA% increase 477), sensitivity and specificity were 64% and 100% respectively. In the essential hypertensives-group, mean PRA% increase was 122; there were three false positives, and both sensitivity and specificity were 88%. This study demonstrates that the PRA response to oral captopril test is a useful screening test for distinguishing small congenital kidney from renal artery stenosis and for identifying the latter in hypertensive patients.

Adolescent↗
PubMed1989

Epinephrine and norepinephrine pattern in elderly patients with borderline and established hypertension.

To evaluate the activity of sympathetic system and of plasm renin in elderly patients with borderline (BH) and established essential hypertension (EH), 31 BH mean age 38 years and 30 EH, mean age 39 years; 15 BH, mean age 66 years, and 15 EH, mean age 68 years, were studied at rest and after dynamic exercise. At the same time blood pressure and heart rate were automatically recorded, while blood samples were collected for PRA and plasma epinephrine (E) and norepinephrine (NE) assays. Plasma E levels showed no significant differences between the groups examined at rest. Nevertheless, young BH had higher plasma E levels than young EH after stress and elderly BH showed plasma E levels higher than age-matched EH in response to dynamic exercise. The PRA behaviour was similar among all the groups, but dynamic exercise induced a greater increase in BH than in EH. Moreover, the stress-induced increase in plasma NE levels was higher in EH than in BH. Our results demonstrate in old BH, as well as in young BH, a response of E to stress greater than in the age-matched EH. In our study BH, both young and old subjects, seem to be characterized by a sympathoadrenal overactivity pointed out by an excessive release of E from the adrenal gland after stress. This exaggerated sympathoadrenal reactivity may constitute an important mechanism in triggering hypertension independent of age.

Adult↗
PubMed1988

Effects of felodipine on natriuresis, atrial natriuretic factor, the renin-angiotensin-aldosterone system, and blood pressure in essential hypertension.

The aim of this study was to evaluate the short-term and long-term effects of felodipine, a new dihydropiridine calcium antagonist, on arterial blood pressure (BP), the renin-angiotensin-aldosterone system, diuresis, natriuresis, and the atrial natriuretic factor (ANF). In 15 essential hypertensives (WHO class II) BP, venous BP at the posterior tibial vein (VBPTV), diuresis, natriuresis, plasma renin activity (PRA), and both plasma aldosterone and ANF levels were evaluated at the end of a washout period and after two and 24 hours and 30, 90, and 180 days of follow-up with felodipine, 5 mg twice daily. The first dose of felodipine induced a significant decrease in BP, which was associated with increases in both heart rate and VBPTV. An acute diuretic and natriuretic effect, increases in ANF and PRA, and a transient decrease in plasma aldosterone levels were also observed. Throughout the follow-up period, the antihypertensive efficacy remained unchanged, whereas variations in electrolyte balance and hormonal parameters quickly disappeared, except for the increase in PRA, which lasted until the 30th day of therapy. In our study, felodipine showed a great antihypertensive activity during both short-term and long-term treatment. Moreover, the effect of the first dose was characterized by transient increases in circulating ANF and decreases in plasma aldosterone concentrations, which were associated with marked diuresis and natriuresis.

Adult↗
PubMed1988

Effects of moderate low sodium/high potassium diet on essential hypertension: results of a comparative study.

It is generally accepted that a significant restriction in sodium intake can lower blood pressure in hypertensive patients and more recently it has also been suggested that a high potassium intake can exert an antihypertensive effect. We have therefore, conducted a double-blind, randomized, cross-over study to evaluate the antihypertensive efficacy of the combination of a modest dietary sodium restriction and a high potassium intake in hypertensive patients of mild and moderate degrees. During the modest sodium (100 mmol/day)/high potassium (130 mmol/day) diet the blood pressure was significantly reduced (-17/-6 mmHg) when compared to the normal diet (160 mmol Na/day and 80 mmol K/day). The blood pressure reduction did not interfere with hemodynamic and humoral responses to dynamic exercise. The modest reduction in sodium intake and increase in potassium content in the diet was well tolerated by the patients.

Adult↗
PubMed1988

Sympathetic activity in borderline and established hypertension in the elderly.

Although increased sympathetic outflow has been implicated in the induction of early essential hypertension, the increase in norepinephrine with advancing age could reflect a compensatory mechanism for a declining peripheral response to adrenergic stimuli or an age-related decrease in norepinephrine clearance. To evaluate the activity of the sympathetic system and of plasma renin in elderly patients with borderline and established essential hypertension, 31 borderline hypertensives aged less than 60 years (mean age 38 years), 30 established essential hypertensives aged less than 60 years (mean age 39 years), 15 borderline hypertensives aged greater than 60 years (mean age 66 years) and 15 essential hypertensives aged greater than 60 years (mean age 68 years) were studied at rest and after dynamic exercise. Blood pressure and the heart rate were automatically recorded and blood samples were collected for plasma renin activity and plasma epinephrine and norepinephrine assays. Plasma epinephrine levels showed no significant differences between the groups examined at rest. Nevertheless, young borderline hypertensives had higher plasma epinephrine levels than young essential hypertensives after stress, and elderly borderline hypertensives showed higher plasma epinephrine levels than the age-matched essential hypertensives in response to dynamic exercise. The plasma renin activity profile was similar among all the groups, but dynamic exercise induced a greater increase in borderline than in essential hypertensives. Moreover, the stress-induced increase in plasma norepinephrine levels was higher in essential than in borderline hypertensives. Our results show a greater epinephrine response to stress in elderly and young borderline hypertensives than in age-matched essential hypertensives.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗