Paola Preti

Effects of insufficient sleep on blood pressure in hypertensive patients A 24-h study

The influence of acute sleep deprivation during the first part of the night on 24-h blood pressure monitoring (ABPM) was studied in 36 never-treated mild to moderate hypertensive patients. According to a crossover design, they were randomized to have either sleep deprivation or a full nights sleep 1 week apart, during which they were monitored with ABPM. Urine samples for analysis of nocturnal urinary excretion of norepinephrine were collected. During the sleep-deprivation day, both mean 24-h blood pressure and mean 24-h heart rate were higher in comparison with those recorded during the routine workday, the difference being more pronounced during the nighttime (P < .01). Urinary excretion of norepinephrine showed a significant increase at night during sleep deprivation (P < .05). Blood pressure and heart rate significantly increased in the morning after a sleep-insufficient night (P < .05). These data suggest that lack of sleep in hypertensive patients may increase sympathetic nervous activity during the night and the following morning, leading to increased blood pressure and heart rate. This situation might represent an increased risk for both target organ damage and acute cardiovascular diseases.

Effects of a Restricted Sleep Regimen on Ambulatory Blood Pressure Monitoring in Normotensive Subjects

The influence of sleep deprivation during the first part of the night on 24-h ambulatory blood pressure monitoring (ABPM) was studied in 18 normotensive subjects. They underwent two ABPM, one week apart: during the first, they slept from 11 PM to 7 AM, and during the second, from 2 AM to 7 AM. The main differences were observed at dawn, before awakening, when SBP and DBP significantly decreased (P < .01) in the restricted sleep regimen, and during the morning after the recovery sleep, when SBP and HR significantly increased (P < .05). The explanation for these findings is not obvious. We suppose that the decrease in SBP and DBP at dawn might be due to a reorganization of the sleep phases in the restricted sleep regimen, whereas the increase in SBP and HR after awakening might be due to a greater sympathetic activation, as though sleep deprivation was a stressful condition.

ACE inhibition but not angiotensin II antagonism reduces plasma fibrinogen and insulin resistance in overweight hypertensive patients.

The aim of this study was to compare the effects of the angiotensin-converting enzyme (ACE) inhibitor perindopril and the angiotensin II antagonist losartan on insulin sensitivity and plasma fibrinogen in overweight hypertensive patients. Twenty-eight overweight mild to moderate [diastolic blood pressure (DBP) >90 and <110 mm Hg] hypertensives aged 43-64 years, after a 4-week placebo period, were randomized to perindopril, 4 mg o.d., or losartan, 50 mg o.d., for 6 weeks. Then, after a new placebo period, patients were crossed to the alternative regimen for further 6 weeks. At the end of the placebo and of the treatment periods, blood pressure was measured, plasma fibrinogen was evaluated, and insulin sensitivity was assessed by the euglycemic, hyperinsulinemic clamp technique. Glucose infusion rate (GIR) during the last 30 min of clamp and total glucose requirement (TGR) were evaluated. Both perindopril and losartan reduced SBP (by a mean of 20.2 mm Hg, p < 0.001 vs. placebo; and 15.8 mm Hg, p = 0.002 vs. placebo, respectively) and DBP (by a mean of 15.2 mm Hg, p = 0.001 vs. placebo, and 11.8 mm Hg, p = 0.01 vs. placebo respectively), with no difference between the two treatments. GIR was significantly increased by perindopril (+2.91 mg/min/kg, p = 0.042 vs. placebo), but not by losartan (+0.28 mg/min/kg, NS). TGR was not modified by losartan but was increased by perindopril (+9.3 g, p = 0.042 vs. placebo). Plasma fibrinogen levels were reduced by perindopril (-53.4 mg/dl, p = 0.022 vs. placebo) but not by losartan (-16.8 mg/dl, NS). The perindopril-induced decrease in fibrinogen was correlated with the increase in GIR (r = 0.39; p < 0.01). These findings suggest that fibrinogen decrease produced by the ACE inhibitor is related to its action on insulin sensitivity, which seems to be dependent not on angiotensin II blockade but rather on other mechanisms.

Effect of valsartan addition to amlodipine on ankle oedema and subcutaneous tissue pressure in hypertensive patients

The aim of this study was to assess the effect of valsartan addition to amlodipine on ankle foot volume (AFV) and pretibial subcutaneous tissue pressure (PSTP), two objective measures of ankle oedema. After a 4-week placebo period, 80 grade 1–2 hypertensive patients (diastolic blood pressure (DBP)>90 mm Hg and <110 systolic blood pressure (SBP)>140 mm Hg) were randomized to amlodipine 10 mg or valsartan 160 mg or amlodipine 10 mg plus valsartan 160 mg for 6 weeks according to an open-label, blinded end point, crossover design. At the end of the placebo period and of each treatment period, blood pressure, AFV and PSTP were evaluated. AFV was measured using the principle of water displacement. PSTP was assessed connecting the subcutaneous pretibial interstitial environment with a water manometer. Both amlodipine and valsartan monotherapy significantly reduced SBP (−16.9 and –14.5 mm Hg, respectively, P<0.01 vs baseline), and DBP (−12.9 and −10.2 mm Hg, respectively, P<0.01 vs baseline) but the reduction was greater with the combination (−22.9 mm Hg for SBP, P<0.01 vs monotherapy; −16.8 mm Hg for DBP, P<0.01 vs monotherapy). Amlodipine monotherapy significantly increased both AFV (+23%, P<0.01 vs baseline) and PSTP (+75.5%, P<0.001 vs baseline) whereas valsartan monotherapy did not influence them. As compared to amlodipine alone, the combination produced a less marked increase in AFV (+6.8%, P<0.01 vs amlodipine) and PSTP (+23.2%, P<0.001 vs amlodipine). Ankle oedema was clinically evident in 24 patients with amlodipine and in six patients with the combination. These results suggest that angiotensin receptor blockers partially counteract the microcirculatory changes responsible for calcium channel blockers induced oedema formation.

Influence of losartan and atenolol on memory function in very elderly hypertensive patients

The aim of this study was to compare the effect of the beta-adrenergic blocker atenolol and the Angiotensin II type 1 (AT1) receptor antagonist losartan on cognitive function in very elderly hypertensive patients. A total of 120 mild to moderate essential hypertensive (DBP >90 and <105 mmHg) patients, aged 75–89 years, were studied. After a 4-week wash-out period on placebo, they were randomized to receive atenolol 50 mg or losartan 50 mg for 24 weeks according to a parallel arm design. At the end of the placebo period and of each active treatment period, BP was measured (by mercury sphygmomanometer, Korotkoff I and V) and cognitive function was evaluated through three different tests (word list memory, word list recall and word list fluency). Both atenolol and losartan were equally effective in reducing SBP (−22.1 and −23.1 mmHg, respectively, P< 0.01 vs baseline) and DBP (−10.3 and −11.2 mmHg, respectively, P< 0.01 vs baseline). Atenolol treatment did not induce significant changes in any test score, whereas losartan significantly increased the score of both the word list memory (+2.2, P<0.05 vs baseline) and the word list recall test (+2.1, P<0.05 vs baseline). The comparison between losartan and atenolol was significant (P<0.05) for both memory tests. These data suggest that in very elderly hypertensive patients, chronic AT1 receptor blockade by losartan could improve cognitive function, in particular immediate and delayed memory.

Prevention of Recurrent Lone Atrial Fibrillation by the Angiotensin-II Converting Enzyme Inhibitor Ramipril in Normotensive Patients

OBJECTIVES The aim of the present study was to verify whether angiotensin-II converting enzyme (ACE) inhibition is also effective in preventing relapses of lone atrial fibrillation (LAF), that is, in the absence of hypertension and/or heart disease. BACKGROUND Several studies have shown that ACE inhibitors are effective in preventing atrial fibrillation (AF) relapses in patients with arterial hypertension or several forms of heart disease, that is, in the presence of clinical conditions that are recognized as causing a higher risk of atrial arrhythmias. METHODS Sixty-two patients admitted to the emergency department of our institution for a first-ever episode of LAF were enrolled in the study after excluding the presence of cardiac or extracardiac conditions known to be associated with an increased risk of AF, by medical history, physical examination, complete echocardiographic study, and the evaluation of blood pressure, thyroid function, urinary catecholamines, serum electrolytes, blood glucose, red blood cell count, and arterial blood gases. After cardioversion to sinus rhythm by intravenous propafenone, patients were randomized to either ramipril 5 mg/day (n = 31) or placebo (n = 31). Holter monitoring and clinical examination were performed every 3 months. RESULTS After a 3-year follow-up, AF relapses were observed in 3 patients treated with ramipril and in 10 patients allocated to placebo (p < 0.03, Kaplan-Meier, log-rank test). During follow-up, none of the patients developed arterial hypertension or other cardiac or extracardiac condition known to be associated with increased risk of AF, that is, in all patients the diagnosis of LAF was confirmed. CONCLUSIONS Ramipril is effective in preventing relapses of LAF.

Prevalence of Primary Aldosteronism among Unselected Hypertensive Patients: A Prospective Study Based on the Use of an Aldosterone/Renin Ratio above 25 as a Screening Test

Primary aldosteronism (PA) has been considered a rare cause of hypertension. The introduction of the aldosterone/renin ratio (ARR) as a screening test has led to an increase in the detection rate. The aim of this study was to evaluate the prevalence of PA among unselected hypertensive patients by using an ARR >25 as a screening test. We studied 3,000 consecutive unselected hypertensive patients. Blood samples for the determination of plasma renin activity (PRA), aldosterone (ALD) and electrolytes were drawn in the morning, and patients with an ARR >25 underwent intravenous saline infusion as a confirmatory test. Adrenal CT and a dexamethasone suppression test were performed in patients with confirmed PA. Patients with a positive dexamethasone test underwent genetic testing for glucocorticoid-remediable aldosteronism (GRA). Out of 3,000 hypertensives, 684 (22.8%) showed an ARR >25 and 177 of them (5.9% of the whole population) had a positive saline loading test. Only 44 of them (24.8%) were hypokalemic. CT was performed in all the patients with confirmed PA and 53 of them (29.9%) had a solitary adrenal macroadenoma, 112 (63.3%) had bilateral adrenal enlargement and 12 (6.8%) had normal appearing adrenal glands. Of 177 patients given dexamethasone to identify GRA, 8 (4.5%) showed aldosterone suppression but only one (0.1%) tested positive for the chimeric gene. In conclusion, our findings indicate that standardized application of an ARR >25 to unselected hypertensive patients, followed by i.v. saline loading as a confirmatory test, can result in the detection of a large number of patients with PA (5.9% of the studied population), most of whom are normokalemic. Bilateral adrenal hypertrophy represents the more common form of PA.

Long-term effects of ramipril and nitrendipine on albuminuria in hypertensive patients with type II diabetes and impaired renal function.

The aim of this study was to compare the effects of ramipril and nitrendipine chronic treatment on urinary albumin excretion (UAE) in hypertensive patients with type II non-insulin-dependent diabetes mellitus (NIDDM) and impaired renal function. A 2-year, prospective, randomised study was conducted on 51 men with a diastolic blood pressure (DBP) ⩾95 and ⩽105 mm Hg, stable NIDDM, serum creatinine between 1.6 and 3.0 mg/dl and persistent UAE >300 and <2000 mg/24 h. after a 3-month preliminary observation period, during which patients began a low-protein, low-sodium diet, and a subsequent 4-week run-in period on placebo, patients were randomly treated with ramipril 5 mg or nitrendipine 20 mg for 2 years. both drugs similarly reduced bp without affecting glucose homeostasis. in the ramipril group uae significantly decreased after only 3 months of treatment, whereas in the nitrendipine group a significant although lesser reduction in uae was observed only after 1 year. during the second year the uae% change was not statistically different between the two treatments. serum creatinine and creatinine clearance showed no significant change with both drugs. the progression of renal insufficiency as assessed by the rate of reduction of creatinine clearance over the 2 years of the study was similar in the ramipril and the nitrendipine groups. in conclusion both ramipril and nitrendipine were associated with a decrease in uae although such a reduction was earlier and more marked with ramipril. the decline of renal function did not differ significantly between the two treatments.

Losartan and perindopril effects on plasma plasminogen activator inhibitor-1 and fibrinogen in hypertensive type 2 diabetic patients

BACKGROUND This study compared the effects of losartan and perindopril on plasma plasminogen activator inhibitor-1 (PAI-1) and fibrinogen in hypertensive type 2 diabetic patients. METHODS We studied 85 nonsmoking outpatients, aged 46 to 64 years, with mild to moderate essential hypertension (diastolic blood pressure [BP] > 90 and < 110 mm Hg) and well controlled type 2 diabetes mellitus. After a 4-week washout placebo period, patients were randomized to received perindopril 4 mg once daily (n = 42) or losartan 50 mg once daily (n = 43) for 12 weeks according to a double-blind, parallel-group design. At the end of the placebo and active treatment periods, BP was measured and plasma PAI-1 and fibrinogen were evaluated. RESULTS Both perindopril and losartan reduced systolic and diastolic BP values (-16/15 mm Hg and -15/14, respectively; P < .001 v placebo), with no difference between the two treatments. Plasma PAI-1 was reduced by perindopril (-10 ng/dL, P = .028 v placebo) but not by losartan (+4 ng/dL, NS), the difference between the two treatments being statistically significant (P < .01). Plasma fibrinogen showed no significant change with both drugs, although a decreasing trend was noted with perindopril. CONCLUSIONS These findings indicate that perindopril but not losartan decreases PAI-1 in hypertensive type 2 diabetic patients, which suggests that the PAI-1 lowering effect is unrelated with AT, receptor blockade and could rather be due to the fact that the endothelial receptors that mediate PAI-1 expression in response to angiotensin II are not type 1 receptor subtypes. Different effects of the two drugs on the bradykinin system might also be implicated.

Differential effects of ACE-inhibition and angiotensin II antagonism on fibrinolysis and insulin sensitivity in hypertensive postmenopausal women.

The aim of this study was to compare the effects of trandolapril and losartan on plasminogen activator inhibitor type 1 (PAI-1) levels and insulin sensitivity in hypertensive postmenopausal women. We studied 89 hypertensive (diastolic blood pressure >90 and <110 mm Hg) postmenopausal women, aged 51 to 60 years not taking any hormone replacement therapy. Diabetic, obese, and smoking patients were excluded. After a 4-week placebo period, they were randomized to receive 2 mg of oral trandolapril (n=45) or 50 mg of oral losartan (n=44) for 12 weeks according to a double-blind, parallel group design. At the end of the placebo and active treatment periods, blood pressure (BP) was measured, plasma samples were drawn to evaluate PAI-1 antigen levels, and insulin sensitivity was assessed. Both trandolapril and losartan reduced systolic BP (by a mean of 16.9 mm Hg and 15.2 mm Hg, respectively, P < .01 v placebo) and diastolic BP (by a mean of 13.1 mm Hg and 11.9 mm Hg, respectively, P < .01 v placebo) with no difference between the two treatments. The PAI-1 antigen levels were significantly decreased by trandolapril (from 36.9+/-21 ng/dL to 27.2+/-17 ng/dL, P < .05), but not by losartan (from 35.3+/-22 ng/dL to 37.1+/-23 ng/dL, P=not significant). Glucose infusion rate was significantly increased by trandolapril (from 6.67+/-0.56 mg/min/kg to 7.9+/-0.65 mg/min/kg, P < .05), but was not significantly modified by losartan (from 6.7+/-0.47 mg/min/kg to 6.9+/-0.50 mg/min/kg, P= not significant). In the trandolapril group the PAI-1 decrease correlated with glucose infusion rate increase (r=0.36, P=.045) These results provide evidence of different effects of angiotensin converting enzyme inhibitors and AT1 antagonists on fibrinolysis and suggest that the PAI-1 decrease induced by angiotensin converting enzyme inhibitors is related to their action on insulin sensitivity and is not dependent on angiotensin II antagonism but rather on other mechanisms. It remains to be seen whether these findings apply to other patient populations than postmenopausal women.