[Usefulness of nitrendipine and its effects on quality of life and brain blood flow in elderly hypertensive patients]

There are many reports on the efficacy of Ca-antagonists for treatment of elderly essential hypertension. In particular, many studies have noted the beneficial effects of antihypertensive therapy on the quality of life (QOL). Nevertheless, there are no reports on antihypertensive therapy regarding the relationship between brain blood flow (BBF) and QOL. Therefore, we examined the efficacy of nitrendipine, a Ca-antagonist, on the brain blood flow and QOL, and its side effects in elderly essential hypertensive patients. The subjects were 17 (males: 4, females: 13) patients with untreated hypertension of WHO stage I or II, aged 70 years or older. The mean dose of nitrendipine was 9.4 +/- 0.4 mg daily. Before and 6 months after treatment, we examined blood pressure (BP), heart rate (HR), echocardiography (left ventricular mass index [LVMI], % fractional shortening [% FS]), plasma noradrenaline (Nad), plasma renin activity (PRA), BBF using the IMP-ARG method with BBF scintigraphy, and QOL was examined with a questionnaire. Two patients were excluded from this study because 1 had no decrease in BP, and another was moved to a different hospital. BP significantly decreased from 178/93 to 137/77 mmHg, but HR was not changed after treatment. BBF significantly increased from 37.0 +/- 4.9 to 41.0 +/- 4.9 ml/dl/min, but % FS, Nad, and PRA did not significantly change. The degree of QOL was improved by 4.2 +/- 1.2 points and there was a significant positive correlation between the changes of BBF and of QOL (r = 0.66, p = 0.04). However, moderate pharmacotherapy for BP seems to be necessary because there were 2 patients whose BBF decreased accompanied by excessive drop in BP after treatment. In conclusion, it is possible to safely use nitrendipine for elderly essential hypertensive patients. Nitrendipine has beneficial effects on BBF, and it was suggested that the increase of BBF is one of the most important factors in improvement of QOL.

[Effects of lotensin and nitrendipine on plasma fibrinogen and platelet aggregation in hypertensive patients]

Plasma fibrinogen and platelet aggregation were measured by turbidimetric immunoassay, turbidimetry in 47 hypertensive patients and 20 normotensive control subjects. Among the 47 hypertensives, 24 cases were received lotensin and 23 nitrendipine. The plasma fibrinogen was increased and platelet aggregation enhanced in hypertensive patients before treatment. Platelet aggregation decreased after 8 weeks of treatment with lotensin or nitrendipine respectively. Lotensin decreased plasma fibrinogen whereas nitrendipine did not. It was concluded that both lotensin and nitrendipine decreased platelet aggregation; lotensin decreased plasma fibrinogen but nitrendipine did not.

Chinese trial on isolated systolic hypertension in the elderly. Systolic Hypertension in China (Syst-China) Collaborative Group

BACKGROUND

In 1988, the Systolic Hypertension in China (Syst-China) Collaborative Group initiated the placebo-controlled Syst-China trial to investigate whether antihypertensive drug treatment could reduce the incidence of fatal and nonfatal stroke in older Chinese patients with isolated systolic hypertension.

OBJECTIVES

To explore (1) whether the benefits of active treatment were evenly distributed across 4 strata, prospectively defined according to sex and previous cardiovascular complications, and (2) whether the morbidity and mortality results were influenced by age, level of systolic or diastolic blood pressure (BP), smoking or drinking habits, or diabetes mellitus at enrollment.

METHODS

Eligible patients had to be 60 years or older with a sitting systolic BP of 160 to 219 mm Hg and diastolic BP less than 95 mm Hg. After stratification for center, sex, and previous cardiovascular complications, 1253 patients were assigned to active treatment starting with nitrendipine (10-40 mg/d), with the possible addition of captopril (12.5-50.0 mg/d), and/or hydrochlorothiazide (12.5-50 mg/d). In the 1141 control patients, matching placebos were used similarly.

RESULTS

Male sex, previous cardiovascular complications, older age, higher systolic BP or lower diastolic BP, living in northern China, smoking, and diabetes mellitus significantly and independently increased the risk of 1 or more of the following end points: total or cardiovascular mortality, all fatal and nonfatal cardiovascular end points, all strokes, and all cardiac end points. In the placebo-control group diabetes raised the risk of all end points 2- to 3-fold (P< or =.05). However, active treatment reduced the excess risk associated with diabetes to a nonsignificant level (P values ranging from .12-.86) except for cardiovascular mortality (P = .04). Cox regression with adjustments applied for significant covariates suggested that active treatment may reduce total mortality more (P = .06) in women and stroke more (P = .07) in men and that it may provide better protection against cardiac end points in nonsmokers than smokers (P = .04). Otherwise, the benefits of active treatment were equally manifest, regardless of the enrollment characteristics of the patients, and regardless of whether active treatment consisted of only nitrendipine or of nitrendipine associated with other active drugs.

CONCLUSIONS

In elderly Chinese patients with isolated systolic hypertension, stepwise antihypertensive drug treatment, starting with the dihydropyridine calcium channel blocker nitrendipine, improved prognosis. The benefit was particularly evident in diabetic patients; for cardiac end points it tended to be larger in nonsmokers. Otherwise, the benefit of active treatment was not significantly influenced by the characteristics of the patients at enrollment in the trial.

Comparative effects of bisoprolol and nitrendipine on exercise capacity in hypertensive patients with regular physical activity

The aim of this study was to evaluate the long-term effects of administering bisoprolol compared with nitrendipine on the duration of the exercise tolerated by male and female patients, aged 18-65 years, having mild to moderate hypertension and taking regular exercise. In this double-blind, randomized prospective study, 96 patients (85 men and 11 women, 48+/-10 years) formed two groups: 49 in the bisoprolol group, and 47 in the nitrendipine group. After a washout period of 14 days, either 10 mg of bisoprolol or 20 mg of nitrendipine was given daily over a treatment period of 12 weeks. During the treatment period, the stability of the physical training was monitored weekly by using a questionnaire. The results of two maximal triangular exercise tolerance tests (ETTs) on an ergometric bicycle performed at D0 under placebo and at D84 under active treatment were compared. No statistical difference was observed between both groups, concerning age, gender, morphologic characteristics, resting cardiovascular parameters, or physical training. Both groups maintained the same training level throughout the study. No significant differences between the groups were noted for duration of ETT [D0 892+/-284 s, D84, 919+/-267 s (NS) vs. D0 929+/-290 s, D84 904+/-324 s (NS)], or maximal work load [D0 190+/-49 W, D84 197+/-48 W (NS) vs. D0 198+/-49 W, D84 196+/-55 W (NS)]. On the other hand, both groups differed in maximal systolic blood pressure [D0 239+/-24 mm Hg, D84 215+/-22 mm Hg (p<0.001) vs. D0 237+/-24 mm Hg, D84 222+/-27 mm Hg (p<0.05)] (p = 0.05), and maximal pulse rate during exercise [141+/-18 vs. 163+/-17] (p<0.001), albeit not in maximal diastolic blood pressure [D0 113+/-13 mm Hg, D84 106+/-17 mm Hg (p<0.05) vs. D0 112+/-13 mm Hg, D84 104+/-15 mm Hg (p<0.05)]. The patient's own perception of the maximal effort (Borg scale) was not significantly different in either of the groups (placebo vs. treatment). Overall, in a population of hypertensive patients taking regular exercise, long-term treatment with bisoprolol produced no significant changes in the duration of peak effort, maximal workload, or the effort perceived by the patients themselves. The effects of regular exercise were comparable in both groups (bisoprolol or nitrendipine). Because previous studies have shown that dihydropyridines do not modify exercise performance in hypertensive patients, it may be concluded that the antihypertensive therapy with bisoprolol is well tolerated in a population of active hypertensive patients during dynamic exercise.

Effects of the calcium antagonists verapamil and nitrendipine on carbamazepine withdrawal

This study was aimed at examining the effects of two frequently used Ca2+ antagonists, nitrendipine and verapamil, on withdrawal after cessation of long-term treatment with the anticonvulsant drug carbamazepine in rats. The 48-h interruption of long-term (21 days) carbamazepine treatment led to the appearance of withdrawal characterized by increases in seizure intensity, the percentage of rats with tonic seizures and mortality. Oral treatment with the two calcium antagonists in combination with carbamazepine abolished the signs of carbamazepine withdrawal. Seizure intensity, the percentage of rats with tonic seizures and mortality in the groups treated with the combinations of carbamazepine + verapamil and carbamazepine + nitrendipine were significantly lower than those of the group of rats treated with carbamazepine alone. In conclusion, some Ca2+ antagonists could attenuate the manifestations of anticonvulsant withdrawal and thus could be used as adjuvants in long-term anticonvulsant therapy.

[Effects of nitrendipine on the development of hypertension and renal failure in Dahl salt-sensitive rats]

The present study investigated the development of hypertension and the functional and morphological changes in the kidney in Dahl salt-sensitive (Dahl S) rats fed with a normal salt diet during aging. Furthermore, the effects of calcium channel antagonists nitrendipine and nicardipine on these changes were examined. The rats showed proteinuria from 6 weeks of age and gradually developed hypertension accompanied by the decrease in the glomerular filtration rate during aging. Glomerular screlosis and degeneration of the renal tubule were found by histological examinations at 17 weeks of age. Nitrendipine (20 mg/kg chow), given from 7 weeks of age for 10 weeks, inhibited the elevation in systolic blood pressure from 3 weeks after the dosing, whereas nicardipine (20 mg/kg chow) inhibited it only at 5 weeks after dosing. Both drugs decreased glomerular sclerosis, but did not affect the glomerular filtration rate, urine volume, urinary excretion of protein and N-acetyl-beta-D-glucosaminidase and serum concentrations of creatinine and urea nitrogen. These results demonstrated that Dahl S rats fed with a normal salt diet spontaneously developed the renal disorder in the early stage of hypertension and reinforce the validity of nitrendipine for the treatment of hypertensive patients with renal failure.

Increased sensitivity to damaging effects of hypoxia and anoxia of isolated hearts from rats after prolonged exposure to ethanol: apparent protection by nitrendipine

The studies described here investigate whether pathologic states that are thought to cause myocardial damage through excess calcium entry (i.e., hypoxia and anoxia) indeed cause greater damage in hearts from ethanol-exposed animals, and whether L-type voltage-operated calcium channels (L-VOCCs) are implicated. Adult male Sprague-Dawley rats were exposed to intoxicating concentrations of ethanol vapor for 6-10 days, and their isolated hearts compared with those of control animals in a Langendorff perfusion system. Hypoxia was induced by perfusion with Krebs-Henseleit buffer, which had not previously been bubbled with oxygen; anoxia was produced by perfusion with buffer bubbled with nitrogen. On reperfusion with oxygenated buffer, evidence of myocardial damage during the hypoxic/anoxic period was obtained by the release of intracellular proteins into the perfusate. After hypoxia, release of myoglobin (MYO) was significantly greater from hearts from ethanol-exposed rats than from controls; other indices of myocardial damage also were increased by hypoxia but did not differ significantly between treatment groups. After anoxic perfusion, release of lactate dehydrogenase (LDH) and creatine phosphokinase (CPK) as well as MYO were all markedly and significantly increased from ethanol-exposed hearts compared with those from control rats. The role of L-VOCCs in this damage was assessed with the calcium channel antagonist nitrendipine (10(-6) M) present in the perfusing buffer immediately before and during the anoxic stimulus. This completely reversed the situation so that preparations from ethanol-exposed rats now showed a reduced release of intracellular proteins compared with hearts from controls. Comparisons with absolute values from the previous experiments suggest that nitrendipine increased release of LDH and CPK from control hearts with little effect on these indices from ethanol-exposed hearts. However, in the case of anoxia-induced MYO release, nitrendipine markedly and significantly reduced this in hearts from ethanol-treated rats but had only a very small effect on the same parameter in controls. The results strongly suggest increased pathologic effects of hypoxia/anoxia in hearts from ethanol-exposed rats. This increased sensitivity may be at least partly a consequence of increased numbers of L-VOCCs in this tissue.

Effect of nitrendipine on renal function in renal-transplant patients treated with cyclosporin: a randomised trial

BACKGROUND

Calcium antagonists such as nitrendipine reduce the effects of cyclosporin on renal haemodynamics, however, their long-term efficacy has not been established. We did a randomised trial to investigate the effects of nitrendipine on renal function in renal-transplant patients treated with cyclosporin.

METHODS

253 renal-transplant patients were recruited: 52 normotensive patients (diastolic blood pressure <90 mm Hg) were assigned placebo and 57 nitrendipine 5 mg twice daily; 71 hypertensive patients (diastolic blood pressure >90 to <115 mm Hg) were assigned placebo and 73 nitrendipine 10 mg twice daily. Nitrendipine was increased to 20 mg twice daily if the target diastolic blood pressure (<90 mm Hg) was not achieved. The patients were seen once a month for 24 months; blood pressure and serum creatinine concentration were recorded at each visit. Analysis was by intention to treat.

FINDINGS

63 patients were withdrawn (35 nitrendipine, 28 placebo). The mean serum creatinine concentration at baseline was slightly higher in the nitrendipine group (146.7 micromol/L [SE 4.42]) than in the placebo group (137.0 micromol/L [3.54]. At the 24-month endpoint or at dropout, serum creatinine concentration was significantly higher in the 123 patients in the placebo group than the 130 patients in the nitrendipine group (160.8 [7.1] vs 148.5 [5.3], p for effect of treatment=0.025, analysis of covariance in a two-way classification; 95% CI for difference -1.77 to -22.98). At study entry, the blood pressures of the placebo and the nitrendipine groups were almost identical. At 24 months, blood pressure was higher in the normotensive patients given a placebo than in those patients given nitrendipine. By contrast, blood-pressure values were similar in those hypertensive patients given a placebo and those given nitrendipine at the end of treatment.

INTERPRETATION

The calcium antagonist nitrendipine has no adverse effects on kidney function in renal-transplant patients with cyclosporin. The drug has a small but significant nephroprotective effect, that is independent of the drug's antihypertensive action.

[Antihypertensive treatment and prevention of dementia]

Hypertension is a risk factor for dementia, particularly vascular dementia. The objective of the "Vascular Dementia" project of the European multicentre Syst-Eur trial was to study the influence of antihypertensive therapy on the incidence of dementia in elderly patients with isolated systolic hypertension included in this trial. Patients were over the age of 60, with systolic blood pressure between 160 and 219 mmHg and diastolic blood pressure less than 95 mmHg in the sitting position and were not demented. After randomization, they were treated under double-blind conditions with nitrendipine associated with or replaced by enalapril or hydrochlorothiazide or an equivalent placebo. Cognitive functions were evaluated by the Mini-Mental State test (MMS) on inclusion then annually. When the MMS score was < or = 23, a complementary assessment was performed to establish the diagnosis of dementia according to DSM III-R criteria. The Modified Ischaemia score specified the aetiology of dementia. A total of 1180 and 1238 subjects were randomized to the placebo and active treatment groups, respectively. They presented comparable characteristics on inclusion. The median intent to treat duration of follow-up was 2.0 years. The incidence of dementia was decreased by 50%, from 7.7 per thousand patient-years in the placebo group to 3.8 per thousand patient-years in the active group (p = 0.05). There were 15 and 8 cases of dementia of the Alzheimer type, 4 and 3 cases of mixed dementia, 2 and 0 cases of vascular dementia in the placebo and active treatment groups, respectively. In conclusion, in subjects over the age of 60 years with isolated systolic HT, antihypertensive treatment initiated with nitrendipine can reduce the incidence of dementia.

Dual mode of action of dihydropyridine calcium antagonists: a role for nitric oxide

Dihydropyridine calcium antagonists have been used for many years in the treatment of angina pectoris and hypertension. According to the common view, their mechanism of action is based on an inhibition of the smooth muscle L-type calcium current, thus decreasing intracellular calcium concentration and inducing smooth muscular relaxation. However, in recent years evidence has accumulated that besides the smooth muscle effects of these agents, their effect on the endothelium must also to be taken into account. It was shown that dihydropyridines can induce the release of nitric oxide (NO) from the vascular endothelium of various vessels and in different species. This was first shown by Günther and colleagues by assaying the methaemoglobin formation in the presence of intact endothelium (in porcine coronary arteries) with and without treatment with nitrendipine. These findings were later confirmed by direct measurement of NO or of nitrite production. In addition, in several preparations, including micro- and macrovasculature, the sensitivity of the vasorelaxing effect of the dihydropyridines to inhibitors of NO-synthase, such as L-N(G)-nitroarginine (LNNA) or L-N-nitro-arginine-methyl-ester (L-NAME), has been shown. With these studies it became evident that the NO-releasing effect was not unique to nitrendipine but was a group phenomenon shared by the dihydropyridines and several nondihydropyridine calcium antagonists. In addition to their action on vascular endothelium, NO release by nifedipine has also been detected in platelets. There are also studies showing long term effects of calcium antagonists involving NO release. Regarding the underlying mechanism of NO release, nitrendipine was shown, not to decrease but to increase intracellular Ca2+ in cultured endothelial cells. This increase was sensitive to both Ca2+-free extracellular superfusion and to gadolinium, a lanthanide known to inhibit shear-stress activated cation channels. This increase in intracellular calcium can activate endothelial NO-synthase, thus inducing the release of NO. These findings on a dual mode of action, i.e. the direct relaxing effect by inhibition of the smooth muscle L-type calcium current and indirect relaxing effect by release of NO from vascular endothelium may help to understand the beneficial antihypertensive effects of the dihydropyridine calcium antagonists and the preferential effect of certain drugs in certain vascular regions (resistance versus conductive vessels). In addition, NO release from both vascular endothelium and platelets may contribute to the antiatherosclerotic and antithrombotic effects described for certain dihydropyridines.

Effect of the calcium channel blocker nitrendipine in normotensive and spontaneously hypertensive, diabetic rats on kidney morphology and urinary albumin excretion

OBJECTIVE

To investigate the effect of nitrendipine on the development of renal changes in experimental diabetes.

DESIGN

Streptozotocin (STZ)-induced diabetic normotensive Wistar rats (WIS) and spontaneously hypertensive rats (SHR) were randomly allocated to nitrendipine treatment (250 mg/kg fodder) or placebo treatment for 6 months.

METHODS

Blood pressure was assessed by the tail-cuff method, urinary albumin excretion (UAE) was determined, and glomerular basement membrane (GBM) thickness, mesangial volume, and mean glomerular volume (MGV) were estimated by morphometric measurements.

RESULTS

In diabetic WIS, nitrendipine significantly reduced UAE after 2 months of treatment (P< 0.05), while no effect was was seen after 4-6 months. In diabetic SHR, no effect on UAE was seen at any time. Nitrendipine was unable to inhibit the renal and glomerular enlargement in diabetic WIS and SHR. Diabetes plus hypertension was associated with significant increase in GBM thickness, while diabetes or hypertension alone showed no significant increase in GBM. Nitrendipine treatment was unable to prevent increased GBM in diabetic SHR.

CONCLUSION

Nitrendipine inhibits an early increase in UAE in normotensive, diabetic rats, but fails to sustain this effect in long-term diabetes. No effect of nitrendipine was observed in SHR.

Amlodipine, a long-acting calcium channel blocker, attenuates morning blood pressure rise in hypertensive patients

1. The effects of once-daily calcium channel blockers with different plasma half-lives on diurnal blood pressure changes were examined in hypertensive patients. 2. Patients with essential hypertension, nine men and 13 women aged 61 +/- 2 years, were treated with amlodipine or nitrendipine in a random cross-over design for 12-16 weeks each. The study drugs were given once daily as monotherapy (n = 8) or in combination with other classes of antihypertensive drugs (n = 14). The plasma half-life of amlodipine is as long as 36 h, while that of nitrendipine is 10 h. At the end of each treatment period, 24 h ambulatory blood pressure and pulse rate were monitored. 3. Average office blood pressure was comparably controlled below 140/90 mmHg by either amlodipine or nitrendipine, both in the monotherapy and the combination therapy groups; however, pulse rate was greater in nitrendipine than in amlodipine either in the monotherapy (by 6 b.p.m., P < 0.05) or in the combination therapy (by 5 b.p.m., P < 0.01). 4. In 24 h blood pressure monitoring, morning (05.30-09.00 h) blood pressure was higher in nitrendipine than in amlodipine by 6/4 mmHg in the monotherapy (P < 0.05) and by 7/5 mmHg in the combination therapy (P < 0.03), although the blood pressure in the remainder of the 24 h did not differ between the two treatment periods. In addition, pulse rate in the daytime (09.30-18.00 h) was greater in nitrendipine than in amlodipine by 6 b.p.m. in the monotherapy (P < 0.01) and by 7 b.p.m. in the combination therapy (P < 0.02). 5. These results suggest slow pharmacokinetics of amlodipine provides an advantage in controlling morning blood pressure and mitigating reflex activation of the sympathetic nervous system.

Opposite effects of ethanol and nitrendipine on nicotine-induced emesis and convulsions

The effects of ICV injections were investigated in unanesthetized cats of ethanol alone and in combination with the dihydropyridine calcium antagonist, nitrendipine, on emesis and the convulsions produced by nicotine, which was similarly injected by the ICV route. In the first series of experiments, short lasting convulsions and emesis were the most prominent symptoms after the ICV injection of nicotine in a dose of 1.0 mg. In the second series of experiments the pretreatment of cats with ethanol given ICV in doses of 0.03, 0.2, and 0.3 ml reduced the emesis and prevented the convulsions induced by 1.0 mg dose of ICV nicotine. In the third series of experiments, the ICV injection of nitrendipine in doses of 0.024, 0.16, and 0.24 mg incorporated in the solution of ethanol, given in volumes of 0.03, 0.2, and 0.3 mt, respectively, blocked emesis but not the convulsions induced by the 1.0 mg dose of nicotine given ICV. The results suggest, therefore, that at least two different mechanisms underlie these phenomena. First, the synergistic effects at the neuronal nicotinic ionophores in the brain would act to underlie the antagonistic action of ethanol and nitrendipine on the emetic response. Second, conformational changes brought about by ethanol at voltage-dependent calcium channels in the brain may antagonize the inhibitory effect of the dihydropyridine calcium antagonist, producing the reversal of convulsions.

Efficacy and tolerability of moexipril and nitrendipine in postmenopausal women with hypertension. MADAM study group. Moexipril as Antihypertensive Drug After Menopause

OBJECTIVE

The aim of this study was to compare the efficacy and tolerability of the new angiotensin-converting enzyme (ACE) inhibitor moexipril and the calcium antagonist nitrendipine in postmenopausal women with mild to moderate hypertension.

METHODS

After a 4-week placebo run-in period, 93 postmenopausal women (age range 44-70 years) with primary hypertension were randomized to receive moexipril 15 mg once daily or nitrendipine 20 mg once daily for 8 weeks. The mean sitting systolic (SSBP) and sitting diastolic blood pressures (SDBP) at baseline were 161.3/103.0 mmHg in the moexipril group, and 162.2/102.3 mmHg in the nitrendipine group.

RESULTS

After the 8 weeks of treatment, the SSBP/SDBP reductions were -21.2/-15.2 mmHg in the moexipril group and -18.2/-13.6 mmHg in the nitrendipine group. Blood pressure responses were adequate in 82.2% of the moexipril-treated patients and in 80.9% in the nitrendipine-treated group. Adverse events were more frequent with nitrendipine than with moexipril. The most common adverse events in the nitrendipine group were headache (23.4%), flushing (21.3%) and ankle oedema (14.9%). In the moexipril group the most common adverse event was cough (8.9%).

CONCLUSION

The results of the study suggest that moexipril and nitrendipine are equieffective in the given dosages. In the patient population of postmenopausal women, the ACE inhibitor moexipril appears to have an advantage over the calcium antagonist nitrendipine with regard to tolerability.

Anticonvulsant profile of nimodipine and nitrendipine against pentylenetetrazole induced seizures in rats

The activity of nimodipine and nitrendipine against pentylenetetrazole (PTZ) induced seizures in Albino rats was studied alone and in combination with valproate. The median effective dose [ED50] of valproate, nimodipine and nitrendipine were initially determined. All the 3 drugs were injected i.p. 30 min before the induction of seizures. Seizures were induced by PTZ 85 mg/kg i.p., and subsequently the effect of combining ED50 doses of nimodipine and nitrendipine with ED50 dose of valproate was evaluated. ED50 of valproate and nitrendipine were 129 and 2.5 mg/kg respectively. ED50 of nimodipine could not be established since a dose-response relationship was not obtained. Hence, for the purpose of combination studies, 4 mg/kg of nimodipine was used. Both nimodipine (4 mg/kg) and nitrendipine (2.5 mg/kg) decreased the ED50 of valproate from 129 to 40 mg/kg. Both nimodipine and nitrendipine potentiate the activity of valproate against PTZ induced seizures and can be considered as potential adjuvant anticonvulsants which merit further study.

Effects of calcium-channel blockade in older patients with diabetes and systolic hypertension. Systolic Hypertension in Europe Trial Investigators

BACKGROUND

Recent reports suggest that calcium-channel blockers may be harmful in patients with diabetes and hypertension. We previously reported that antihypertensive treatment with the calcium-channel blocker nitrendipine reduced the risk of cardiovascular events. In this post hoc analysis, we compared the outcome of treatment with nitrendipine in diabetic and nondiabetic patients.

METHODS

After stratification according to center, sex, and presence or absence of previous cardiovascular complications, 4695 patients (age, > or =60 years) with systolic blood pressure of 160 to 219 mm Hg and diastolic pressure below 95 mm Hg were randomly assigned to receive active treatment or placebo. Active treatment consisted of nitrendipine (10 to 40 mg per day) with the possible addition or substitution of enalapril (5 to 20 mg per day) or hydrochlorothiazide (12.5 to 25 mg per day) or both, titrated to reduce the systolic blood pressure by at least 20 mm Hg and to less than 150 mm Hg. In the control group, matching placebo tablets were administered similarly.

RESULTS

At randomization, 492 patients (10.5 percent) had diabetes. After a median follow-up of two years, the systolic and diastolic blood pressures in the placebo and active-treatment groups differed by 8.6 and 3.9 mm Hg, respectively, among the diabetic patients. Among the 4203 patients without diabetes, systolic and diastolic pressures differed by 10.3 and 4.5 mm Hg, respectively, in the two groups. After adjustment for possible confounders, active treatment was found to have reduced overall mortality by 55 percent (from 45.1 deaths per 1000 patients to 26.4 deaths per 1000 patients), mortality from cardiovascular disease by 76 percent, all cardiovascular events combined by 69 percent, fatal and nonfatal strokes by 73 percent, and all cardiac events combined by 63 percent in the group of patients with diabetes. Among the nondiabetic patients, active treatment decreased all cardiovascular events combined by 26 percent and fatal and nonfatal strokes by 38 percent. In the group of patients receiving active treatment, reductions in overall mortality, mortality from cardiovascular disease, and all cardiovascular events were significantly larger among the diabetic patients than among the nondiabetic patients (P=0.04, P=0.02, and P=0.01, respectively).

CONCLUSIONS

Nitrendipine-based antihypertensive therapy is particularly beneficial in older patients with diabetes and isolated systolic hypertension. Thus, our findings do not support the hypothesis that the use of long-acting calcium-channel blockers may be harmful in diabetic patients.

Glomerular size-selective dysfunction in NIDDM is not ameliorated by ACE inhibition or by calcium channel blockade

BACKGROUND

In patients with insulin-dependent diabetes mellitus (IDDM) and overt nephropathy glomerular barrier size-selectivity progressively deteriorates with time and is effectively improved by angiotensin converting enzyme (ACE) inhibition. Whether similar glomerular functional changes develop in proteinuric patients with non-insulin-dependent diabetes mellitus (NIDDM), and whether antihypertensive agents can favorably affect glomerular filtration of macromolecules in these patients, has not been documented yet.

METHODS

We investigated renal hemodynamics and fractional clearance of neutral dextrans of graded sizes, in nine proteinuric patients with NIDDM and renal biopsy findings of typical diabetic glomerulopathy. Six healthy volunteers served as controls. We also investigated the effects of an ACE inhibitor and of a calcium channel blocker, both given in doses targeted to achieve a comparable level of systemic blood pressure control, on glomerular hemodynamics and sieving function. Theoretical analysis of glomerular macromolecule transport was adopted to evaluate intrinsic glomerular membrane permeability properties.

RESULTS

Fractional clearance of large macromolecules (42 to 66 A in radius) was significantly higher in diabetic patients than in controls, and the distribution of membrane pore radii was calculated to be shifted towards larger pore sizes in diabetics (mean radius increased from 55 to 60 A). Despite effective blood pressure control, neither antihypertensive affected glomerular hemodynamics to any significant extent. Fractional clearance of dextrans, as well as of albumin and IgG, and total urinary proteins were not modified by either treatments.

CONCLUSIONS

These data indicate that patients with NIDDM and overt nephropathy develop abnormalities in size-selective function of the glomerular barrier and, at variance to IDDM, such changes were not ameliorated either by ACE inhibition or calcium channel blockade.

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) > or =95 and < or =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.

Comparison of active treatment and placebo in older Chinese patients with isolated systolic hypertension. Systolic Hypertension in China (Syst-China) Collaborative Group

BACKGROUND

Isolated systolic hypertension occurs in around 8% of Chinese people aged 60 years or older. 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 in older patients with isolated systolic hypertension.

METHODS

All patients were initially started on masked placebo. After stratification for centre, sex and previous cardiovascular complications, alternate patients (n=1253) were assigned nitrendipine at 10-40 mg daily, with the addition of captopril at 12.5-50.0 mg daily or hydrochlorothiazide at 12.5-50.0 mg daily, or both, if a sufficient blood pressure fall was not obtained. In the remaining 1141 control patients, matching placebos were administered similarly.

RESULTS

At entry, sitting blood pressure averaged 170.5 mmHg systolic and 86.0 mmHg diastolic, age averaged 66.5 years and total serum cholesterol was 5.1 mmol/l. After 2 years of follow-up, sitting systolic and diastolic blood pressures had fallen by 10.9 mmHg and 1.9 mmHg in the placebo group and by 20.0 mmHg and 5.0 mmHg in the active treatment group. The intergroup differences were 9.1 mmHg systolic (95% confidence interval 7.6-10.7 mmHg ) and 3.2 mmHg diastolic (95% confidence interval 2.4-4.0). Active treatment reduced total strokes by 38% (from 20.8 to 13.0 endpoints per 1000 patient-years, P=0.01), all-cause mortality by 39% (from 28.4 to 17.4 endpoints per 1000 patient-years, P=0.003), cardiovascular mortality by 39% (from 15.2 to 9.4 endpoints per 1000 patient-years, P=0.03), stroke mortality by 58% (from 6.9 to 2.9 endpoints per 1000 patient-years, P=0.02), and ail fatal and nonfatal cardiovascular endpoints by 37% (from 33.3 to 21.4 endpoints per 1000 patient-years, P=0.004).

CONCLUSIONS

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.

Benazepril causes in hypertension a greater reduction in left ventricular mass than does nitrendipine: a randomized study using magnetic resonance imaging

To assess the comparative effects of benazepril and nitrendipine monotherapies on left ventricular mass index (LVMI) in hypertensive patients with echocardiographically determined left ventricular hypertrophy, patients with diastolic blood pressure (BP) > or = 100 mm Hg were randomized to benazepril, 10 mg, or nitrendipine, 20 mg, both given once or twice daily. After 4 weeks, only the responders (diastolic BP <90 mm Hg) entered a 5-month maintenance period. At baseline, and after 3 and 6 months, LVMI was blindly estimated by means of magnetic resonance imaging (MRI) and, for comparison, by means of echocardiography. Of the 50 randomized patients, three were excluded from the study as nonresponders after 4 weeks; moreover, two patients taking benazepril and one taking nitrendipine discontinued the treatment after 2 months for adverse effects. Both monotherapies reduced systolic and diastolic BP to a similar extent. After 3 months, MRI-estimated LVMI decreased by 21.5 g/m2 in the benazepril and 8.8 g/m2 in the nitrendipine group, with an adjusted mean difference between the two groups of 11.1 g/m2 (95% CI, 7.3-14.8 g/m2; p = 0.0001). After 6 months, it decreased by 23.6 g/m2 and 10.0 g/m2, respectively, with an adjusted mean difference of 11.3 g/m2 (95% CI, 7.5-15.5; p = 0.0001) in favor of benazepril. In conclusion, despite a similar antihypertensive effect, benazepril led to a greater reduction in MRI-measured LVMI than did nitrendipine (-16.2% vs. -7.2%) in hypertensive patients with left ventricular hypertrophy.

Parallel comparative trial of amlodipine and nitrendipine monotherapy in patients with essential hypertension

OBJECTIVES

To compare the blood pressure effects of two dihydropyridine calcium channel blockers, amlodipine and nitrendipine, in 488 patients with essential hypertension.

METHODS

The study used a randomized, single-blind design of 4 weeks' duration conducted at four medical centres in China. Patients were randomized to receive either amlodipine monotherapy (5-10 mg once daily; n = 334) or nitrendipine (10 mg twice or three times daily; n = 1 54). Blood pressure was evaluated by standard blood pressure measurements before and after treatment, and by 24 h ambulatory blood pressure monitoring in a subgroup of patients (n = 18).

RESULTS

Both systolic and diastolic blood pressures were reduced from baseline after 4 weeks of amlodipine and nitrendipine monotherapy. Diastolic blood pressure was reduced by 14.4% in the amlodipine group, which was significantly better than the 13.0% reduction in the nitrendipine group (P< 0.05). In addition, blood pressure response rates were significantly better with amlodipine monotherapy than with nitrendipine monotherapy. In the subgroup of patients undergoing 24 h ambulatory blood pressure monitoring, both systolic and diastolic blood pressure were reduced from baseline in the amlodipine and nitrendipine groups. Adverse effects were generally mild, with dizziness, flushing, palpitation, headache, drowsiness and ankle oedema being the most common. Rushing and headache were more frequent in the nitrendipine group than in the amlodipine group (P< 0.05 for flushing and P<0.01 for headache).

CONCLUSIONS

Amlodipine monotherapy reduced blood pressure more effectively than nitrendipine monotherapy in patients with essential hypertension and was associated with fewer adverse events.

Calcium antagonists and thiazide diuretics have opposite effects on blood rheology and radial artery compliance in arterial hypertension: a randomized double-blind study

In addition to their effects on blood pressure, antihypertensive agents may produce additional effects on blood rheology and arterial compliance abnormalities which may play a role in target-organ damage. However, these effects may depend only on the specific pharmacological properties of certain antihypertensive agents, and may be partly unrelated to blood pressure lowering action. We compared the effects of nitrendipine 20 mg once daily to hydrochlorothiazide 25 mg once daily in 33 mildly to moderately hypertensive and otherwise healthy patients, in a double blind parallel group trial. Blood rheology (blood fibrinogen and protein concentrations, hematocrit, plasma viscosity and whole blood viscosity at shear rates 0.2 to 128 s-1, erythrocyte deformability and aggregation) and radial artery diameter and compliance (Nius I + Finapres) were measured at baseline and after 2 months of treatment. Both drugs produced similar blood pressure lowering. Blood viscosity increased for all shear rates in the hydrochlorothiazide group and decreased in the nitrendipine treated group. Erythrocyte deformability increased in the nitrendipine but not in the thiazide group. Radial artery diameter and compliance were not different between the two groups but there was a trend towards an increase in cross-sectional compliance in the hydrochlorothiazide group and towards a decrease in the nitrendipine group. Our data show that, in mildly hypertensive patients, blood pressure control by nitrendipine produced more favourable effects on relevant rheological variables than hydrochlorothiazide. Radial artery compliance changes tended to be altered also in opposite directions by the two agents. The significance and the clinical relevance of these effects may require further investigations.

Subgroup and per-protocol analysis of the randomized European Trial on Isolated Systolic Hypertension in the Elderly

BACKGROUND

In 1989, the European Working Party on High Blood Pressure in the Elderly started the double-blind, placebo-controlled, Systolic Hypertension in Europe Trial to test the hypothesis that antihypertensive drug treatment would reduce the incidence of fatal and nonfatal stroke in older patients with isolated systolic hypertension. This report addresses whether the benefit of antihypertensive treatment varied according to sex, previous cardiovascular complications, age, initial blood pressure (BP), and smoking or drinking habits in an intention-to-treat analysis and explores whether the morbidity and mortality results were consistent in a per-protocol analysis.

METHODS

After stratification for center, sex, and cardiovascular complications, 4695 patients 60 years of age or older with a systolic BP of 160 to 219 mm Hg and diastolic BP less than 95 mm Hg were randomized. Active treatment consisted of nitrendipine (10-40 mg/d), with the possible addition of enalapril maleate (5-20 mg/d) and/or hydrochlorothiazide (12.5-25 mg/d), titrated or combined to reduce the sitting systolic BP by at least 20 mm Hg, to below 150 mm Hg. In the control group, matching placebo tablets were employed similarly.

RESULTS

In the intention-to-treat analysis, male sex, previous cardiovascular complications, older age, higher systolic BP, and smoking at randomization were positively and independently correlated with cardiovascular risk. Furthermore, for total (P = .009) and cardiovascular (P = .09) mortality, the benefit of antihypertensive drug treatment weakened with advancing age; for total mortality (P = .05), the benefit increased with higher systolic BP at entry, while for fatal and nonfatal stroke (P = .01), it was most evident in nonsmokers (92.5% of all patients). In the perprotocol analysis, active treatment reduced total mortality by 24% (P = .05), reduced all fatal and nonfatal cardiovascular end points by 32% (P<.001), reduced all strokes by 44% (P = .004), reduced nonfatal strokes by 48% (P = .005), and reduced all cardiac end points, including sudden death, by 26% (P = .05).

CONCLUSIONS

In elderly patients with isolated systolic hypertension, stepwise antihypertensive drug treatment, starting with the dihydropyridine calcium channel blocker nitrendipine, improves prognosis. The per-protocol analysis suggested that treating 1000 patients for 5 years would prevent 24 deaths, 54 major cardiovascular end points, 29 strokes, or 25 cardiac end points. The effects of antihypertensive drug treatment on total and cardiovascular mortality may be attenuated in very old patients.