A review of the prescribing trend of thiazide-type and thiazide-like diuretics in hypertension: A UK perspective

Thiazide diuretics have been the cornerstone of hypertension treatment for >5 decades. Most recent European and American guidelines recommend both thiazide-type and thiazide-like diuretics as first-line drugs for all patients with hypertension. In contrast, diuretics are not regarded as first-line treatment in the UK and in patients who are to be initiated on a diuretic treatment, thiazide-like molecules, such as chlortalidone and indapamide are the preferred option. This review examines the prescribing trend of the 4 most commonly prescribed thiazide diuretics for the treatment of hypertension in the UK. Prescription cost analysis data were obtained for both 2010 and 2016/2017 for each region of the UK to analyse the impact of the 2011 National Institute for Health and Care Excellence hypertension guidelines on the trend in thiazide diuretic prescribing. Overall, the prescriptions of thiazide diuretics declined over the years. Bendroflumethiazide is the most commonly prescribed diuretic in the UK and despite some geographical differences, thiazide-type diuretics are more widely used than thiazide-like. The use of indapamide increased significantly between 2010 and 2016/2017 while chlortalidone was rarely employed. Of the many factors affecting trends in prescriptions, clinical inertia, treatment adherence, availability of the products and the lack of fixed dose combinations may play a role.

Pharmacotherapy for hypertension in adults aged 18 to 59 years

BACKGROUND

Hypertension is an important risk factor for adverse cardiovascular events including stroke, myocardial infarction, heart failure and renal failure. The main goal of treatment is to reduce these events. Systematic reviews have shown proven benefit of antihypertensive drug therapy in reducing cardiovascular morbidity and mortality but most of the evidence is in people 60 years of age and older. We wanted to know what the effects of therapy are in people 18 to 59 years of age.

OBJECTIVES

To quantify antihypertensive drug effects on all-cause mortality in adults aged 18 to 59 years with mild to moderate primary hypertension. To quantify effects on cardiovascular mortality plus morbidity (including cerebrovascular and coronary heart disease mortality plus morbidity), withdrawal due adverse events and estimate magnitude of systolic blood pressure (SBP) and diastolic blood pressure (DBP) lowering at one year.

SEARCH METHODS

The Cochrane Hypertension Information Specialist searched the following databases for randomized controlled trials up to January 2017: the Cochrane Hypertension Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (from 1946), Embase (from 1974), the World Health Organization International Clinical Trials Registry Platform, and ClinicalTrials.gov. We contacted authors of relevant papers regarding further published and unpublished work.

SELECTION CRITERIA

Randomized trials of at least one year' duration comparing antihypertensive pharmacotherapy with a placebo or no treatment in adults aged 18 to 59 years with mild to moderate primary hypertension defined as SBP 140 mmHg or greater or DBP 90 mmHg or greater at baseline, or both.

DATA COLLECTION AND ANALYSIS

The outcomes assessed were all-cause mortality, total cardiovascular (CVS) mortality plus morbidity, withdrawals due to adverse events, and decrease in SBP and DBP. For dichotomous outcomes, we used risk ratio (RR) with 95% confidence interval (CI) and a fixed-effect model to combine outcomes across trials. For continuous outcomes, we used mean difference (MD) with 95% CI and a random-effects model as there was significant heterogeneity.

MAIN RESULTS

The population in the seven included studies (17,327 participants) were predominantly healthy adults with mild to moderate primary hypertension. The Medical Research Council Trial of Mild Hypertension contributed 14,541 (84%) of total randomized participants, with mean age of 50 years and mean baseline blood pressure of 160/98 mmHg and a mean duration of follow-up of five years. Treatments used in this study were bendrofluazide 10 mg daily or propranolol 80 mg to 240 mg daily with addition of methyldopa if required. The risk of bias in the studies was high or unclear for a number of domains and led us to downgrade the quality of evidence for all outcomes.Based on five studies, antihypertensive drug therapy as compared to placebo or untreated control may have little or no effect on all-cause mortality (2.4% with control vs 2.3% with treatment; low quality evidence; RR 0.94, 95% CI 0.77 to 1.13). Based on 4 studies, the effects on coronary heart disease were uncertain due to low quality evidence (RR 0.99, 95% CI 0.82 to 1.19). Low quality evidence from six studies showed that drug therapy may reduce total cardiovascular mortality and morbidity from 4.1% to 3.2% over five years (RR 0.78, 95% CI 0.67 to 0.91) due to reduction in cerebrovascular mortality and morbidity (1.3% with control vs 0.6% with treatment; RR 0.46, 95% CI 0.34 to 0.64). Very low quality evidence from three studies showed that withdrawals due to adverse events were higher with drug therapy from 0.7% to 3.0% (RR 4.82, 95% CI 1.67 to 13.92). The effects on blood pressure varied between the studies and we are uncertain as to how much of a difference treatment makes on average.

AUTHORS' CONCLUSIONS

Antihypertensive drugs used to treat predominantly healthy adults aged 18 to 59 years with mild to moderate primary hypertension have a small absolute effect to reduce cardiovascular mortality and morbidity primarily due to reduction in cerebrovascular mortality and morbidity. All-cause mortality and coronary heart disease were not reduced. There is lack of good evidence on withdrawal due to adverse events. Future trials in this age group should be at least 10 years in duration and should compare different first-line drug classes and strategies.

Urinary zinc excretion during treatment with different diuretics

Urinary zinc excretion was studied in a randomized trial in 9 patients during treatment with bendroflumethiazide, chlorthalidone and hydrochlorothiazide and in another 9 patients during treatment with bumetanide, furosemide and triamterene. During treatment with the thiazides, the zinc concentration rose by 30% and the total amount of zinc excretion increased by 60%. In contrast, during treatment with the loop-diuretics, urine zinc concentration diminished and the total amount of zinc excretion increased much less than during therapy with the thiazides. With respect to the importance of zinc as an essential element in human metabolism and the frequency of diuretic treatment, the observed increased urinary losses of zinc deserve further attention.

Plasma renin activity and blood pressure during long term treatment with propranolol and diuretic

19 primary hypertensive patients were treated in random succession with diuretic, propranolol and the combination of both. It was found that the diuretic gave a sustained increase in plasma renin activity (PRA). There was a negative correlation between PRA level attained and blood pressure reduction. Propranolol treatment gave a sustained reduction of PRA. There was no correlation between PRA reduction and blood pressure reduction. When diuretic was combined with propranolol, PRA was in average at control level, and there was no correlation between the PRA reduction from diuretic value to combination value and the corresponding additional blood pressure fall. It is concluded that propranolol treatment does not transform patients to "low renin hypertensives" specifically sensitive to diuretic treatment.

Atenolol versus bendroflumethiazide in middle-aged and elderly hypertensives

The antihypertensive effect and patient tolerability during 12 weeks' treatment with atenolol and bendroflumethiazide were evaluated in an open, randomized, between-patient trial. Out of a total of 162 patients, aged 50-75 years, with previously untreated hypertension, 151 completed the trial. They were randomly allocated to two groups. Forty-nine patients, aged 50-64 years (middle-aged), and 23, aged 65-75 years (elderly), were treated with atenolol. Forty middle-aged and 39 elderly were treated with bendroflumethiazide. Significant reductions in blood pressure (BP) were observed during treatment with each drug (p less than 0.001). The change in diastolic BP in middle-aged patients was significant in favour of atenolol (p less than 0.01), but otherwise no difference was found between the two drugs. Uric acid increased during treatment with both drugs (p less than 0.001). Serum potassium decreased during bendroflumethiazide treatment (p less than 0.001). Subjective side-effects of both drugs were few and expected. The results of this study indicate that atenolol and bendroflumethiazide are equally effective in reducing BP in patients aged 50-75 years.

Antihypertensive effect of atenolol (100 mg once a day) and methyldopa (250 mg thrice a day). A double-blind cross-over multicentre study

In a double-blind cross-over multicentre study lasting for 16 weeks, the antihypertensive effect of atenolol (100 mg once a day) was compared with that of methyldopa (250 mg thrice a day) in 48 patients with mild to moderately severe hypertension. At the end of the trial, atenolol was superior to methyldopa in achieving clinically relevant BP levels, less than 150/95 mmHg (p less than 0.001), and in respect to patients' drug preference (p less than 0.04). The BP levels after the first 2 weeks of treatment with either drug were identical but, in contrast to methyldopa, atenolol caused further significant reduction in BP during the following 4 weeks. This finding implies that one should hesitate to start additional therapy until after at least six weeks of atenolol treatment, whereas no further reduction in BP can be expected after the first 2 weeks of treatment with methyldopa. Two patients had to be withdrawn from the study during treatment with atenolol, as they developed severe bradycardia and dyspnoea, respectively. Other side-effects were few and of minor clinical importance.

Comparative natriuretic and diuretic efficacy of theophylline ethylenediamine and of bendroflumethiazide during long-term treatment with the potent diuretic bumetanide. Permutation trial tests in patients with congestive heart failure

The additive natriuretic and diuretic effects of theophylline ethylenediamine and of bendroflumethiazide have been compared in permutation trial tests in patients with advanced congestive heart failure receiving long-term treatment with the highly potent diuretic, bumetanide. Statistical analysis of renal water and electrolyte excretion revealed that theophylline ethylenediamine, 400 mg orally, and bendroflumethiazide, 5 mg orally, had very similar effects, both quantitatively and qualitatively. The mechanism of action of the supplementary diuretics is discussed. It is concluded that theophylline ethylenediamine represents a useful alternative to thiazide diuretics when supplementary natriuretic treatment is considered in patients with congestive heart failure during long-term treatment with potent diuretics. The significance of maintaining the potassium balance during such a combined regimen is stressed.

Renal excretion of electrolytes in patients on long-term diuretic therapy for arterial hypertension and/or congestive heart failure

Renal excretion, skeletal muscle content and plasma concentration of electrolytes were studied in 108 patients on long-term diuretic therapy for congestive heart failure and/or arterial hypertension. As reference populations served a group of 16 healthy volunteers and a group of 22 patients with liver cirrhosis, but not on diuretic therapy. Diuretic therapy was found to deprive the patients of their ability to conserve potassium and magnesium when there was a simultaneous cellular depletion of these ions. Magnesium excretion was found to be correlated to the skeletal muscle magnesium content. An inverted Na/K ratio in urine and a low magnesium excretion were fair indicators of cellular magnesium depletion.

Antihypertensive effect and side-effects of bendroflumethiazide and propranolol

The antihypertensive effect and side-effects during 12 months' treatment with bendroflumethiazide and propranolol have been compared in two randomly selected, equally large groups (n= 53) of previously untreated male hypertensives. Systolic BP above 170 or diastolic BP above 105 mmHg on two occasions were defined as hypertension. The same BP reduction was achieved in both groups. During the 12 months' treatment one subject on bendroflumethiazide developed diabetes mellitus and one on propranolol developed cardiac decompensation. None developed gout. Contrary to what had been presumed, glucose tolerance improved during 12 months' treatment with both agents, while there were no changes in fasting blood sugar, insulin or triglyceride concentrations. No changes were found in serum potassium or total body potassium during 12 months' bendroflumethiazide treatment, while serum potassium increased during treatment with propranolol. Uric acid increased slightly during treatment with both agents. Prolongation of the follow-up to 24 months did not change any of the findings regarding metabolic changes during treatment. The frequency of subjective side-effects decreased to the same extent during treatment with both drugs. It is concluded that bendroflumethiazide and propranolol are equally useful as antihypertensive agents and that the risk of impariment of glucose metabolism and potassium balance seems to be very slight during treatment with bendroflumethiazide in mild hypertension.

[Hypertension--does it matter how blood pressure is lowered?]

ASCOT compared the effect of atenolol combined with a thiazide versus amlodipine with perindopril in hypertensive patients. It also studied the effect of atorvastatin in those with normal cholesterol. ASCOT concluded that reductions in cardiovascular events with atorvastatin were significant, and that amlodipine-based treatment prevented more cardiovascular events. The latter seemed to be due to better control of central blood pressure. Both statin and amlodipine-based treatments were cost-effective. According to the ASCOT study, it does matter how blood pressure is lowered.

The spironolactone, amiloride, losartan, and thiazide (SALT) double-blind crossover trial in patients with low-renin hypertension and elevated aldosterone-renin ratio

BACKGROUND

There is continuing variation in diagnosis and estimated prevalence of primary hyperaldosteronism. The higher estimates encourage search for adrenal adenomas in patients with elevated ratios of plasma aldosterone to renin. However, it is more likely that patients with normal plasma K+ and aldosterone belong to the polygenic spectrum of low-renin hypertension rather than have the same monogenic syndrome as classic Conn's. Our primary hypothesis was that in low-renin patients with normal plasma K+ and aldosterone, a thiazide diuretic, bendroflumethiazide, would be as effective as spironolactone in overcoming the Na+ retention and lowering blood pressure. Secondary objectives were to compare the dose response for each diuretic and to evaluate amiloride as an alternative to spironolactone.

METHODS AND RESULTS

Fifty-seven patients entered and 51 patients completed a placebo-controlled, double-blind, randomized crossover trial. Entry criteria included low plasma renin, normal K+, elevated aldosterone-renin ratio, and a previous systolic blood pressure response to spironolactone of > or = 20 mm Hg. Two doses each of spironolactone and bendroflumethiazide were compared. The crossover also included amiloride and losartan. Outcome measures were blood pressure, plasma renin, and other biochemical markers of diuretic action. Spironolactone 100 mg and bendroflumethiazide 5 mg caused similar falls in systolic blood pressure, whereas bendroflumethiazide 2.5 mg was 5/2 mm Hg less effective in reducing blood pressure than either bendroflumethiazide 5 mg or spironolactone 50 mg (P<0.005). Amiloride 40 mg was as effective as the other diuretics. Biochemical indices of natriuresis showed bendroflumethiazide to be less effective than either spironolactone or amiloride; plasma renin rose 4-fold on spironolactone but only 2-fold on bendroflumethiazide (P=0.003).

CONCLUSIONS

In hypertensive patients with a low plasma renin but normal K+, bendroflumethiazide 5 mg was as effective as spironolactone 100 mg in lowering blood pressure, despite patients being selected for a previous large fall in blood pressure on spironolactone. Because this result differs from that expected in primary hyperaldosteronism, our finding argues against low-renin hypertension including a large, undiagnosed pool of primary hyperaldosteronism. However, spironolactone was the more effective natriuretic agent, suggesting that inappropriate aldosterone release or response may still contribute to the Na+ retention of low-renin hypertension.

Effects of "newer" and "older" antihypertensive drugs on hemorrheological, platelet, and endothelial factors. A substudy of the Anglo-Scandinavian Cardiac Outcomes Trial

BACKGROUND

Different antihypertensive therapies may exert benefits via not only a reduction in blood pressure but also in improving the risk of thrombosis.

METHODS

We tested the hypothesis that a more modern antihypertensive drug regimen (ie, amlodipine +/- perindopril) would have a more beneficial effect on hemorheological markers (white blood-cell count [WCC], plasma viscosity [PV], hematocrit [HCT], and fibrinogen)--and on plasma von Willebrand factor (vWf, an index of endothelial damage and dysfunction) and soluble P-selectin (sP-sel, an index of platelet activation), compared with an older antihypertensive drug regimen (ie, atenolol +/- bendroflumethiazide).

RESULTS

After 6 months, PV, sP-sel, and HCT fell in both groups (P < .01), while fibrinogen was unchanged. However, those 74 patients randomized to amlodipine +/- perindopril had significant reductions in WCC (P = .005), with no significant changes in vWF or platelet count. Conversely, in those 85 patients randomized to atenolol +/- bendroflumethiazide, there were significant reductions in vWF (P = .001) and platelet count (P = .011) but no significant reductions in WCC. There were no significant differences in the levels of any of the variables between the two arms of the trial, nor a significant difference in the magnitude of reduction between the two treatment arms.

CONCLUSIONS

Within the constraints of this substudy design, there was no differential effect apparent of the two antihypertensive treatment arms on hemorheological parameters or endothelial and platelet function (as assessed by vWF and sP-sel), suggesting that other pathophysiological mechanisms may be involved.

Does the aldosterone:renin ratio predict the efficacy of spironolactone over bendroflumethiazide in hypertension? A clinical trial protocol for RENALDO (RENin-ALDOsterone) study

Background

High blood pressure is an important determinant of cardiovascular disease risk. Treated hypertensives do not attain a risk level equivalent to normotensives. This may be a consequence of suboptimal blood pressure control to which indiscriminate use of antihypertensive drugs may contribute. Indeed the recent ALLHAT[1]study suggests that thiazides should be given first to virtually all hypertensives. Whether this is correct or whether different antihypertensive therapies should be targeted towards different patients is a major unresolved issue, which we address in this study.

The measurement of the ratio of aldosterone: renin is used to identify hypertensive subjects who may respond well to treatment with the aldosterone antagonist spironolactone. It is not known if subjects with a high ratio have aldosteronism or aldosterone-sensitive hypertension is debated but it is important to know whether spironolactone is superior to other diuretics such as bendroflumethiazide in this setting.

Methods/design

The study is a double-blind, randomised, crossover, controlled trial that will randomise 120 hypertensive subjects to 12 weeks treatment with spironolactone 50 mg once daily and 12 weeks treatment with bendroflumethiazide 2.5 mg once daily. The 2 treatment periods are separated by a 2-week washout period. Randomisation is stratified by aldosterone: renin ratio to include equal numbers of subjects with high and low aldosterone: renin ratios.

Primary Objective – To test the hypothesis that the aldosterone: renin ratio predicts the antihypertensive response to spironolactone, specifically that the effect of spironolactone 50 mg is greater than that of bendroflumethiazide 2.5 mg in hypertensive subjects with high aldosterone: renin ratios.

Secondary Objectives – To determine whether bendroflumethiazide induces adverse metabolic abnormalities, especially in subjects with high aldosterone: renin ratios and if baseline renin measurement predicts the antihypertensive response to spironolactone and/or bendrofluazide

Discussion

The numerous deleterious effects of hypertension dictate the need for a systematic approach for its treatment. In spite of various therapies, resistant hypertension is widely prevalent. Among various factors, primary aldosteronism is an important cause of resistant hypertension and is now more commonly recognised. More significantly, hypertensives with primary aldosteronism are also exposed to various other deleterious effects of excess aldosterone. Hence treating hypertension with specific aldosterone antagonists may be a better approach in this group of patients. It may lead on to better blood pressures with fewer medications.

Delayed Cardiotoxicity in Chronic Lithium Poisoning: Discrepancy between Serum Lithium Concentrations and Clinical Status

Chronic lithium poisoning is characteristically associated with greater toxicity than acute ingestion. Neurotoxic features may occur within several hours, whereas major cardiovascular effects are typically not seen until later. This report describes profound bradycardia as a late consequence of chronic lithium poisoning, and reminds us to consider the possibility of delayed toxic effects, even in situations where serum lithium concentrations appear to be declining.

Does aldosterone-to-renin ratio predict the antihypertensive effect of the aldosterone antagonist spironolactone?

BACKGROUND

The recognition that some 10% to 15% of the hypertensive population may have aldosterone excess has increased the frequency of measurement of the aldosterone-to-renin ratio (ARR) and the use of aldosterone antagonists. Whether this ratio will predict the blood pressure (BP) response to spironolactone is not clear.

METHODS

We correlated the BP response to spironolactone 50 mg/day to baseline ARR in 69 hypertensive patients (mean [+/-SD] age 57 +/- 2 years, 65% male), consisting of 39 subjects with long-standing hypertension (4.0 +/- 0.2 years) whose hypertension was uncontrolled on at least three antihypertensive medications and 30 previously untreated patients who were randomized in a cross-over design to receive either spironolactone 50 mg/day or bendroflumethiazide 2.5 mg/day for 4 weeks.

RESULTS

After 4 weeks of spironolactone, BP in patients with never-treated hypertension was reduced by 18 +/- 3 / 11 +/- 1 mm Hg. There was a highly significant correlation between log ARR and the fall in systolic BP (r = 0.69, P < .001) and diastolic BP (r = 0.45, P < .05). Nine of ten patients with low renin activity (< or =0.5 ng/mL/h) showed a >20-mm Hg fall in systolic BP. No such correlations were seen when BP was reduced by bendroflumethazide 2.5 mg. For patients with resistant hypertension, despite a BP reduction of 28 +/- 3 / 13 +/- 2 mm Hg after 14 weeks of spironolactone, there was no relationship between the reduction in BP and the ARR; however, subjects with pretreatment potassium <4.0 mmol/L had a greater response than those with levels > or =4.0 mmol/L (34 +/- 3 / 16 +/- 2 v 20 +/- 6 / 8 +/- 3 mm Hg, P < .05)

CONCLUSIONS

Based on the study results, ARR and low renin activity may predict the response to spironolactone in never-treated hypertensive patients but not in patients taking antihypertensive drugs, possibly because of the effect of these agents on ARR. In such patients a trial of spironolactone is required to assess the BP response.

Doxazosin versus bendrofluazide: a comparison of the metabolic effects in British South Asians with hypertension

BACKGROUND

People from British South Asian communities have an increased risk of mortality from coronary heart disease (CHD). Doxazosin, a selective alpha(1)-adrenergic blocker, in addition to lowering blood pressure, has been shown to have positive effects on glucose metabolism and lipid profiles in patients with hypertension.

AIM

We studied doxazosin (1-8 mg) and bendrofluazide (2.5 mg) in patients of British South Asian origin with existing mild to moderate hypertension (doxazosin n = 78; bendrofluazide n = 82), to compare their effects on glucose and lipid metabolism in this group.

DESIGN OF STUDY

A 34-week randomised, double-blind, parallel-group, multicentre study.

SETTING

Primary care in the UK.

METHOD

All doxazosin patients started with an initial dose of 1 mg once daily, titrated to a maximum 8 mg once daily if diastolic blood pressure was >90 mmHg or was not <5 mmHg of the baseline value. The primary efficacy variables were mean glucose and total cholesterol concentrations at week 21.

RESULT

Doxazosin reduced glucose, total cholesterol, low-density lipoprotein-cholesterol and triglycerides and increased high-density lipoprotein-cholesterol. There were significant differences between doxazosin and bendrofluazide for glucose concentrations at week 21 (P = 0.029) and week 34 (P = 0.015), total cholesterol at week 21 (P = 0.048) and triglycerides at week 21 (P = 0.047) and week 34 (P = 0.009). There was no significant difference in blood pressure lowering between the two treatments.

CONCLUSION

Doxazosin exhibits beneficial effects on glucose concentrations and lipid profile, in particular in lowering triglyceride concentrations in British South Asians. Whether these desirable characteristics translate to improved overall cardiovascular risk requires formal evaluation.

[Old or new antihypertensives--which are better?]

Some of the reported findings of numerous studies on the treatment of hypertension are still giving rise to heated discussions. The result is conflicting recommendations and uncertainty among care-providing physicians. Today, the substances from the group of more recent hypertensive agents (calcium antagonists, ACE-inhibitors and angiotensin 1 receptor blockers) together with the classical agents (diuretics and beta blockers) are recognized as equally justifiable as the five agents of first choice in the treatment of uncomplicated hypertension. If, however, accompanying diseases are present, the choice of primary medication depends on the respective risk (diabetes, etc.) of the individual patient. In many cases, combination treatment should be considered from the very beginning.

Differential cognitive outcomes in the Hypertensive Old People in Edinburgh study

Hypertension is associated with cognitive impairment in older adults. The Hypertensive Old People in Edinburgh (HOPE) study reported improved scores in two psychometric tests in those subjects with the greatest fall in diastolic blood pressure during a 24-week randomised, double-blind trial of captopril versus bendrofluazide in 81 elderly hypertensive people with mild cognitive impairment. Three hundred and eighty-seven of the original sample of 603 older people with and without hypertension and/or cognitive impairment from which the trial subsample was drawn were available for adequate psychometric testing 4 years later. Blood pressure was related prospectively to Raven's Progressive Matrices (RPM), a measure of fluid intelligence, but not memory differences. RPM scores were obtained at baseline, 6 weeks, 12 weeks and at the end of the randomised controlled trial. For subjects on captopril mean scores at each time point adjusted for blood pressure change were 27.6 (95% CI 25.5-29.6), 27.2 (95% CI 25.1-29.2), 28.4 (95% CI 26.6-30.3) and 28.9 (95% CI 26.9-30.9), and for bendrofluazide 27.1 (95% CI 25.1-29.0), 28.9 (95% CI 26.9-30.9), 28.9 (95% CI 27.2-30.7) and 28.7 (95% CI 26.8-30.6). There was a significant improvement in scores for those on bendrofluazide compared with captopril at week 6 (F=8.10, p=0.006, partial eta2=0.11). There were no significant effects for either drug or blood pressure at any time point for tests of memory. Future trials of the effects of antihypertensive therapy on cognition should focus more on outcomes other than memory. Early differential effects of therapeutic agents may not be maintained.

Aldosterone-to-renin ratio, arterial stiffness, and the response to aldosterone antagonism in essential hypertension

BACKGROUND

Some 10% to 15% of hypertensive patients have hyperaldosteronism, an increased ambulant aldosterone-to-renin ratio. As aldosterone reduces arterial compliance, we examined the relationship between aldosterone-to-renin ratio, aortic blood pressure (BP), arterial stiffness, and the effect of spironolactone in a hypertensive population.

METHODS

In 24 untreated patients (mean age 51 +/- 2 years, 10 women), we assessed arterial stiffness by augmentation index-height of the late systolic peak in the aorta, pulse pressure (Sphygmocor), and aortic pulse wave velocity (Complior).

RESULTS

There were significant positive correlations between the aldosterone-to-renin ratio and aortic systolic pressure, aortic pulse pressure, and augmentation index and negative correlations with pulse pressure amplification, but none with brachial BP or pulse wave velocity. After randomization in a cross-over design to 50 mg of spironolactone or 2.5 mg of bendroflumetazide for 4 weeks with washout period of 1 month, both drugs significantly reduced brachial BP, but only spironolactone reduced (P < .001) pulse wave velocity and augmentation index, which remained significant when corrected for its greater reduction in mean BP. There were significant (P < .001) positive correlations between the ratio and decrease in aortic systolic (r = 0.78), mean (r = 0.75), diastolic BP (r = 0.66), aortic pulse pressure (r = 0.69, augmentation index (r = 0.64) and with, brachial systolic pressure (r = 0.66), brachial pulse pressure (r = 0.44, P < .05) and pulse pressure amplification (r = 0.46, P < .05). Such relationships were not found with pulse wave velocity.

CONCLUSIONS

The aldosterone-to-renin ratio may have an important role in determining arterial stiffness, particularly wave reflection and aortic systolic pressure and is of predictive value for the responsiveness to spironolactone. Aldosterone antagonism has BP-independent effects on arterial stiffness.

The systemic haemodynamic and cerebral autoregulatory effects of bendrofluazide in the subacute post-stroke period

INTRODUCTION

Little data exist on the efficacy in terms of blood pressure reduction or outcome measures for the various antihypertensive agents in patients post-stroke. In this study the effects of bendrofluazide on blood pressure levels and variability, dynamic cerebral autoregulation and cardiac baroreceptor sensitivity were assessed in the sub-acute stroke period.

METHODS

A total of 36 hypertensive ischaemic stroke patients were randomized to oral bendrofluazide 2.5 mg daily or matching placebo starting 10 days post-ictus and continued for 28 days. A total of 12 hypertensive controls were similarly randomized in a double-blind, crossover study, each limb being of 28 days duration. Cerebral blood flow velocity, non-invasive beat-to-beat blood pressure levels, electrocardiograms (ECGs) and transcutaneous carbon dioxide levels were measured before and at the end of each treatment period in stroke and control subjects.

RESULTS

Casual blood pressure levels were not significantly reduced in stroke patients with bendrofluazide, but in the placebo group levels increased by 13 +/- 13/6 +/- 7 mmHg (P < 0.001) at study termination. In the control group, casual systolic blood pressure fell during active treatment by 12 +/- 16 mmHg (P < 0.03) compared with placebo. Dynamic cerebral autoregulation, beat-to-beat blood pressure variability and cardiac baroreceptor sensitivity did not change with bendrofluazide or placebo in either the stroke patients or controls.

CONCLUSION

Bendrofluazide does not appear to be an effective hypotensive agent in the sub-acute post-stroke period but may limit the blood pressure rise seen during stroke recovery. Bendrofluazide however does not adversely influence dynamic cerebral autoregulation, blood pressure variability or cardiac baroreceptor sensitivity in either strokes or control subjects.

Skeletal muscle magnesium content is correlated with plasma glucose concentration in patients with essential hypertension treated with lisinopril or bendrofluazide

The association between change in glucose metabolism and change in skeletal muscle magnesium (Mg) concentration induced by antihypertensive treatment was evaluated in 37 patients with essential hypertension randomly treated with either lisinopril or bendrofluazide. Before and after 6 months of treatment, skeletal muscle biopsies were performed, glucose tolerance was determined by oral (OGTT) and intravenous glucose tolerance tests (IVGTT), and insulin sensitivity was assessed by the hyperinsulinemic euglycemic clamp technique. An inverse relationship was found between the treatment-induced change in fasting plasma glucose concentration and change in skeletal muscle Mg concentration (r = -0.39, P < .05). However, there was no significant correlation between skeletal muscle Mg content and either insulin sensitivity measured by the hyperinsulinemic euglycemic clamp test or glucose tolerance evaluated by IVGTT and OGTT. In conclusion, an increased circulating glucose concentration was correlated with a decreased Mg concentration in skeletal muscle during antihypertensive treatment. However, the Mg concentration in skeletal muscle did not significantly predict the insulin sensitivity or glucose tolerance.

Von Willebrand factor, soluble P-selectin, and target organ damage in hypertension: a substudy of the Anglo-Scandinavian Cardiac Outcomes Trial (ASCOT)

To investigate the relationship between soluble markers of platelet, endothelial and rheological function, and target organ damage and their response to intensified management in a population of middle-age hypertensive patients at high risk of cardiovascular complications, we studied 382 consecutive patients (308 men; mean age, 63 years, SD 8) along with 60 normotensive controls free of cardiovascular disease. Patients were divided into those with target organ damage (TOD; n=107) and those free of end-organ damage. Plasma levels of soluble P-selectin (sP-sel), a marker of platelet activation, and von Willebrand factor (vWF), an index of endothelial damage/dysfunction (both enzyme-linked immunosorbent assay), and the rheological indices fibrinogen, plasma viscosity, hematocrit, platelet, and white cell count were measured. In 53 patients, variables were further measured after 6 months of intensified cardiovascular risk management. Patients with TOD had significantly higher vWF, 137 (SD 33) versus 125 (SD 33) IU/dL (P=0.002,) and a greater proportion of smokers, 31% versus 16% (P=0.002). There were no statistically significant differences in plasma viscosity, fibrinogen, hematocrit, white blood cell count, platelet count, or sP-sel between the 2 subgroups. In multivariate analysis, vWF was a significant independent predictor for TOD. After 6 months of intensified management in 53 patients who entered the trial, there were significant reductions in systolic blood pressure, total cholesterol, hematocrit, plasma viscosity, sP-sel, and vWF (all P<0.01) but no significant change in fibrinogen. In conclusion, there is a relationship between TOD and endothelial damage/dysfunction in hypertension. Intensified management results in improvements in hemorheology, endothelial and platelet function.

A comparison of selected antihypertensives and the use of conventional vs ambulatory blood pressure in the detection and treatment of hypertension

This multicenter, randomized, double-blind, parallel group study was undertaken to determine the effectiveness of selected antihypertensives (doxazosin, amlodipine, enalapril, and bendrofluazide) in maintaining 24-hour control of blood pressure (BP). The predictive value of ambulatory (A)BP versus clinic (C)BP measurements as a method for detecting patients with hypertension was also evaluated. A total of 204 patients were screened and of these 110 were diagnosed as mild to moderately hypertensive with clinic diastolic BP 100-110 mm Hg (> or =95 mm Hg in patients with coronary heart disease risk factors). The 4 antihypertensives were all equally effective at controlling BP over 24 h, as shown by 24-hour ABP measurements. The incidence of adverse events was similar for all 4 treatment groups; headache was the most common event, being reported by 22 patients (20%). There was a clinically relevant reduction in total cholesterol for the doxazosin (-15.4 mg/dl) and amlodipine (-11.6 mg/dl) treatment groups in comparison with enalapril and bendrofluazide. Our results from ABP measurements suggest that the antihypertensives studied are effective first-line therapy in the regulation of hypertension and that ABP is a reproducible measure. ABP may also be useful in identifying patients with various types of high BP, for instance those with 'white coat' hypertension, enabling more accurate screening and diagnosis.

Beta-blockers vs. thiazides in the treatment of hypertension: a review of the experience of the large national trials

The effects of antihypertensive treatment on cerebrovascular disease and coronary artery disease (CAD) end points reported in the large-scale national trials have differed. All trials have shown stroke benefit, whereas CAD benefit has not been convincingly demonstrated in any. In three trials, the effects of thiazide- and beta-blocker-based regimens can be directly compared. In the MRC Treatment Trial for Mild Hypertension in Britain, the largest of the trials and the only one to compare these two classes of drugs with each other and with untreated controls, stroke benefit was significantly greater in the thiazide than in the beta-blocker group (p = 0.002). Indeed, the 70% reduction in fatal strokes and 65% reduction in nonfatal strokes suggested an effect on cerebral infarction as well as on cerebral hemorrhage. Opposing trends were found for CAD end points with beta-blockers and thiazides when compared with controls. For coronary events, sudden deaths, and ECG changes of infarction, significant differences were found between the reduced rates for those receiving propranolol and the higher rates for those receiving bendrofluazide. Weak evidence has been put forward by four trials-MRFIT, HDFP, the Oslo trial, and the MRC trial-suggesting that thiazide treatment for those who already have evidence of coronary disease may be harmful. In no case is the evidence conclusive, and it involves only a small (but important) subgroup. In the MRC trial, a nonselective beta-blocker, propranolol, provided greater CAD benefit as measured by the incidence of myocardial infarction, sudden death, and ECG changes, but only in nonsmokers. Hypotheses generated by these trials need further investigation.

Nebivolol reverses endothelial dysfunction in essential hypertension: a randomized, double-blind, crossover study

BACKGROUND

Vascular endothelial dysfunction may predict future atherosclerosis. Hence, an antihypertensive agent that reverses endothelial dysfunction and lowers blood pressure might improve the prognosis of patients with hypertension. We hypothesized that nebivolol, a vasodilating beta-blocker, could improve endothelial dysfunction. We tested this hypothesis by comparing the effects of nebivolol and atenolol on endothelial function.

METHODS AND RESULTS

Twelve hypertensive patients with a mean ambulatory blood pressure of 154+/-7/97+/-10 mm Hg were randomized after a 2-week placebo run-in period (baseline) in a double-blind, crossover fashion to 8-week treatment periods with either 5 mg of nebivolol with 2.5 mg of bendrofluazide or 50 mg of atenolol with 2.5 mg of bendrofluazide. Forearm venous occlusion plethysmography and intra-arterial infusions of acetylcholine and N(G)-monomethyl-L-arginine (L-NMMA) were used to assess stimulated and basal endothelium-dependent nitric oxide release, respectively. Sodium nitroprusside was used as an endothelium-independent control. Nebivolol/bendrofluazide and atenolol/bendrofluazide each lowered the clinic blood pressure to the same extent (132+/-7/82+/-6 and 132+/-9/83+/-8 mm Hg, respectively; P<0.001 from baseline). The vasodilatory response to acetylcholine was significantly increased with nebivolol/bendrofluazide (maximum percentage change in forearm blood flow [mean+/-SEM], 435+/-27%, P<0.001) but not with atenolol/bendrofluazide. Similarly, the endothelium-dependent vasoconstrictive response to L-NMMA was significantly improved only with nebivolol treatment (percentage change in forearm blood flow, -54+/-5%; P<0.001). The response to sodium nitroprusside was not different between treatments, suggesting that the endothelium-independent pathway was unaffected.

CONCLUSIONS

Nebivolol/bendrofluazide increased both stimulated and basal endothelial nitric oxide release, whereas for the same degree of blood pressure control, atenolol/bendrofluazide had no effect on nitric oxide bioactivity. Thus, nebivolol may offer additional vascular protection in treating hypertension.

Improvement in midwall myocardial shortening with regression of left ventricular hypertrophy

Despite normal indices of left ventricular (LV) chamber function, patients with LV hypertrophy (LVH) due to hypertension are thought to have depressed midwall systolic shortening compared with normotensives. The aims of the present study were (1) to confirm this observation and (2) to assess the effects of antihypertensive therapy that cause regression of LVH on LV systolic function assessed at both the midwall and endocardium. Thirty-eight previously untreated hypertensive subjects with LVH underwent echocardiography and were compared with 38 normotensive control subjects. Comparisons between the group with LVH and the control group revealed no significant differences in cardiac output (4. 32+/-0.23 versus 4.55+/-0.21 L/min), ejection fraction (62.5+/-2% versus 66.4+/-1.07%), or endocardial fractional shortening (34.5+/-1.45% versus 37.0+/-0.82%), but shortening assessed at the midwall was significantly less in the group with LVH (17.9+/-1.11% versus 21.6+/-0.63%, P<0.01). Subsequently, 32 patients with uncontrolled hypertension (24 previously untreated and 8 on existing antihypertensive therapy) underwent treatment with ramipril, with the addition of felodipine and bendrofluazide if required, to reduce blood pressure to <140/90 mm Hg. These 32 patients underwent echocardiography at baseline, after blood pressure control, and after an additional 6 months of tight blood pressure control. Good blood pressure control was achieved after 6 months compared with baseline (143/86+/-2.8/1.4 versus 174/103+/-4.1/1.9 mm Hg; P<0.01) with significant regression of LV mass index (124+/-3.4 versus 145+/-3.8 g/m(2), P<0.01). LV fractional shortening assessed at the midwall improved with regression of LVH (21.9+/-0.84 and 18.7+/-1. 19%, P<0.05), with posttreatment midwall shortening being similar to that of the normal control subjects evaluated in the first study. Hypertensive patients with LVH have depressed midwall systolic shortening despite normal indices of LV chamber function. Regression of LVH after good blood pressure control improved midwall shortening to normal levels.

Does the Dundee Step Test predict outcome in treated hypertension? A sub-study protocol for the ASCOT trial. Anglo-Scandinavian Cardiac Outcome Trial

Treated hypertensive subjects may remain five times more likely to die of cardiac and cerebrovascular diseases than normotensive subjects with equivalent resting blood pressure (BP) levels. Research evidence suggests that exercise BP is a better predictor of end-organ damage and mortality than resting BP, and data from our centre show that a significant proportion of treated hypertensives have uncontrolled BP during a 5-min Dundee Step Test. The prognostic usefulness of exercise BP has yet to be translated into clinical practice because of the lack of a suitable technique. The Dundee Step Test is being evaluated in the ASCOT (Anglo-Scandinavian Cardiac Outcome Trial) study, a 5-year follow-up multicentre, multinational trial comparing the effect of newer (amlodipine and perindopril) and older (bendroflumethiazide and atenolol) antihypertensive agents stratified according to cholesterol levels on cardiac outcome. If the value of the Dundee Step Test is proven, then it may be adopted into routine clinical practice for the assessment of exercise BP. This may result in the improved management of hypertension with a subsequent reduction in morbidity and mortality. The publication of this study protocol is meant to be a statement of on-going research which may stimulate interest among those with an interest in this area of research. Journal of Human Hypertension (2000) 14, 75-78.

Impact of antihypertensive treatment on quality of life: comparison between bisoprolol and bendrofluazide

OBJECTIVES

To compare quality of life with the selective beta1-blocker bisoprolol and the thiazide diuretic bendrofluazide in patients with mild to moderate hypertension.

DESIGN AND SETTING

Multi centric, randomised, double-blind, two-way crossover study carried out at six general practice centres.

SUBJECTS

Eighty-one patients with newly diagnosed or previously treated hypertension, who had a mean diastolic blood pressure (BP) of 95-120 mm Hg after receiving placebo for 4-6 weeks.

INTERVENTIONS

In random order, patients received bisoprolol (5 mg once daily) or bendrofluazide (2. 5 mg once daily) for 8 weeks.

MAIN OUTCOME MEASURES

Quality of life and antihypertensive effect.

RESULTS

Decrease in systolic/diastolic BP did not differ between bisoprolol (10 +/- 2/13 +/- 1 mm Hg) and bendrofluazide (9 +/- 2/11 +/- 1 mm Hg). Between bisoprolol and bendrofluazide neither in the intention-to-treat nor in the efficacy analysis any difference was found in quality of life variables, such as Health Status Index, somatic symptoms, anxiety, depression, total psychiatric morbidity, cognitive symptoms and hostility score. Compared to baseline the Health Status Index improved (P < 0.05) during bisoprolol. None of the other investigated quality of life variables changed compared to baseline. No patients dropped out during bisoprolol or bendrofluazide treatment. Although, the total number of reported adverse events appeared lower during bendrofluazide than during bisoprolol treatment, it is unclear whether drug related adverse events also differ between the two drugs.

CONCLUSIONS

At equipotent antihypertensive dosages, the effect of an 8-week treatment on quality of life does not differ between the selective beta1-blocker bisoprolol and the thiazide diuretic bendrofluazide.

A randomised double-blind study comparing nifedipine GITS 20 mg and bendrofluazide 2.5 mg administered once daily in mild-to-moderate hypertension

A multicentre, randomised, double-blind, parallel group comparison of nifedipine GITS 20 mg (Adalat LA) once daily and bendrofluazide 2.5 mg once daily in patients with mild-to-moderate hypertension was conducted. Two hundred patients with a diastolic blood pressure (BP) in the range 95 to 109 mm Hg were randomised to active treatment for 6 weeks. For the per-protocol efficacy population, both treatments resulted in clinically significant mean reductions of trough diastolic BP (nifedipine GITS -8.9 mm Hg, bendrofluazide -7.9 mm Hg) and systolic BP (nifedipine GITS -10.4 mm Hg, bendrofluazide -10.5 mm Hg). The study demonstrated that nifedipine GITS was 'at least equivalent' to bendrofluazide in the reduction of trough diastolic BP (one-sided upper 95% confidence limit, 0.5 mm Hg), where inequivalence had been pre-defined as a difference in mean diastolic BP of > or =5 mm Hg. Both drugs were well tolerated, the overall incidence of adverse events in the nifedipine GITS treatment group being 34.0% (34/100) and in the bendrofluazide treatment group being 29.0% (29/100). The commonest events (incidence > or =5%) were headache, constipation, 'flu syndrome and vasodilatation with nifedipine GITS and headache and nausea with bendrofluazide. An increased incidence of elevations of plasma urea and glucose was observed in patients treated with bendrofluazide (9.6% and 30.4% respectively) compared to those treated with nifedipine GITS (3.1% and 18.8% respectively). Nifedipine GITS 20 mg once daily is 'at least equivalent' to bendrofluazide 2.5 mg once daily in reduction of blood pressure in patients with mild-to-moderate hypertension.

Fibromyalgia in hyperkalemic periodic paralysis

A 43-year-old woman presented at the age of 38 with joint pains and muscle stiffness. Tender points were found fulfilling ACR criteria (1) for fibromyalgia. She had well developed muscles and decreasing muscle power since the age of 35. Muscle pains increased after exercise. Her 10-year-old son had similar symptoms and one paralytic attack. Muscle pain and fatigue increasing with age were found by history in three close relatives. Forearm cold water test produced myotonia in both mother and son. Electromyography was normal and muscle biopsy showed minor unspecific changes. Biochemical investigation of muscle mitochondrial function was normal. Peroral potassium load test produced complete muscle paralysis at a potassium serum level of 5.0 mmol/l. Autosomal dominant hyperkalemic periodic paralysis was diagnosed. Frequent carbohydrate enriched meals, peroral bendroflumethiazide and restriction to submaximal exercise improved muscle and joint pain. Salbutamol peroral spray relieved the periodic weakness.

A diuretic is more effective than a beta-blocker in hypertensive patients not controlled on amlodipine and lisinopril

The combination of an angiotensin-converting enzyme inhibitor and a calcium antagonist has a synergistic effect in patients with more severe hypertension. However, when this combination fails to control blood pressure, it is not clear which drug is then additive. The aim of this work was to study in a double-blind, randomized, crossover design the effect on blood pressure of the addition of either a thiazide diuretic (bendrofluazide, 5 mg once daily) or a beta-blocker (atenolol, 100 mg once daily) or placebo each for a month in hypertensive patients who are not adequately controlled on the combined treatment of amlodipine 5 mg once daily and lisinopril 5 mg twice daily. Eighteen patients with a supine diastolic pressure of more than 90 mm Hg after at least 1 month on the combined treatment of amlodipine and lisinopril were enrolled in the study. The results show that in patients whose blood pressures are not controlled by the combination of amlodipine and lisinopril, the addition of bendrofluazide 5 mg once daily causes a significant fall in blood pressure compared with placebo and a significantly greater fall than 100 mg atenolol once daily.

Non-islet cell tumour-associated hypoglycaemia: 111In-octreotide imaging and efficacy of octreotide, growth hormone and glucocorticosteroids

A patient presented with frequent episodes of spontaneous hypoglycaemia due to a solitary fibrous tumour of pleural origin, secreting incompletely processed pro-insulin-like growth factor II (big IGF-II). Somatostatin receptors were demonstrated in the tumour by 111 inlabelled octreotide scintigraphy, but despite maximal doses of octreotide, there was no suppression of big IGF-II secretion and the hypoglycaemia persisted. The combination of GH and glucocorticoid therapy abolished the hypoglycaemia.

The blood pressure response to antihypertensive treatment with lisinopril or bendrofluazide is related to the calcium and magnesium contents in skeletal muscle

To evaluate the association between skeletal muscle mineral balance and effect of antihypertensive treatment, 37 patients with essential hypertension, randomly treated with either lisinopril or bendrofluazide, were investigated with skeletal muscle biopsies before and after 6 months of treatment. The ratio between calcium and magnesium concentrations in skeletal muscle prior to treatment predicted the blood pressure response during active treatment (r = -0.38, P < .02). During treatment the change in blood pressure was related to the change in muscle Ca/Mg ratio (r = 0.35, P < .05), especially in the patients treated with lisinopril. Thus, an association between the calcium and magnesium balance in skeletal muscle and the blood pressure response to antihypertensive treatment was found in the present study.

Prostacyclin biosynthesis in essential hypertension before and during treatment

Protacyclin biosynthesis was investigated in 133 untreated newly diagnosed patients with uncomplicated essential hypertension. Urinary excretion of 6-oxo-prostaglandin F1 alpha and of 2,3-dinor-6-oxo-prostaglandin F1 alpha, stable breakdown products of prostacyclin, was measured following a 1 month run-in period. To determine whether lowering blood pressure (BP) influenced prostacyclin biosynthesis, 106 consenting patients with diastolic pressure 90-120 mm Hg were allocated randomly to treatment with bendrofluazide, metoprolol, quinapril or amlodipine in an open parallel group design. Dose was increased to reduce diastolic arterial pressure to <90 mm Hg. Terazosin was added if this target BP was not achieved, and its dose increased if necessary. Urinary excretion rates of prostaglandins were measured after 1 year in patients in whom the target diastolic pressure was achieved. Mean arterial pressure varied from 106-168 mm Hg in untreated patients and excretion of both prostacyclin-derived products varied from <5 to >350 ng/g creatinine. Arterial pressure and prostaglandin excretion were not significantly correlated. In 57 patients in whom target pressure was achieved, BP before treatment was 166 +/- 2/100 +/- 1 at baseline and 144 +/- 2/86 +/- 1 mm Hg at 1 year. Excretion rates of each prostacyclin-derived product were similar before treatment and at 1 year, with no significant differences between the drugs. These findings do not support the hypothesis that deficient prostacyclin biosynthesis contributes to the pathogenesis of essential hypertension, or that increased prostacyclin biosynthesis plays a part in the response to treatment with antihypertensive medication.

A comparison of the effects of low- and conventional-dose thiazide diuretic on insulin action in hypertensive patients with NIDDM

In conventional doses, thiazide diuretics impair glucose tolerance and decrease insulin sensitivity, making them an unpopular choice for treating diabetic patients with hypertension. However, use of low-dose thiazide diuretics may avoid the adverse metabolic effects seen with conventional doses. In a double-blind, randomised crossover study we assessed peripheral and hepatic insulin action in 13 hypertensive non-insulin-dependent diabetic patients after a 6-week placebo run-in and following two 12-week treatment periods with either low (1.25 mg) or conventional (5.0mg) dose bendrofluazide. There were no differences between doses in their effects on systolic and diastolic blood pressure. Bendrofluazide 1.25 mg had significantly less effect on serum potassium, uric acid, fasting glucose and HbA1C concentrations than the 5.00 mg dose. Exogenous glucose infusion rates required to maintain euglycaemia were significantly different between doses (p < 0.05) with conventional-dose bendrofluazide worsening peripheral insulin resistance compared to baseline (23.8 +/- 2.9 vs 27.3 +/- 3.5 mumol.kg-1.min-1, p < 0.05) and low-dose bendrofluazide producing no change compared to baseline (26.8 +/- 3.6 vs 27.3 +/- 3.5 mumol.kg-1.min-1, p = NS). Postabsorptive endogenous glucose production was higher on treatment with bendrofluazide 5.0 mg compared to 1.25 mg (11.7 +/- 0.5 vs 10.2 +/- 0.3 mumol.kg-1.min-1, p < 0.05) and suppressed to a lesser extent following insulin (4.0 +/- 0.7 vs 2.0 +/- 0.4 mumol.kg-1.min-1, p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Angiotensin-converting enzyme inhibition in diabetic nephropathy: ten years' experience

The aim of our prospective study was to evaluate putative progression promoters, kidney function, and prognosis during long-term treatment with angiotensin-converting enzyme inhibition in insulin-dependent diabetes mellitus patients suffering from diabetic nephropathy. Eighteen consecutive hypertensive insulin-dependent diabetes patients with nephropathy (mean age, 33 years) who had not been treated previously were all treated with captopril in combination with frusemide or bendrofluazide. The four patients who were refractory to this regimen also received nifedipine. Treatment was continued for a median of 8.9 years (range, 6.3 to 9.8, years). Renal function was assessed every 6 months by measurement of glomerular filtration rate (GFR) (single-bolus 51Cr-EDTA technique) and albuminuria by radioimmunoassay. Baseline values (+/- SE) were mean arterial blood pressure 146/93 +/- 3/1 mm Hg, albuminuria (geometric mean +/- antilog SE) 982 +/- 1.2 micrograms/min, and GFR 98 +/- 5 mL/min/1.73 m2. Angiotensin-converting enzyme inhibition induced a significant reduction during the whole treatment period of blood pressure (137/85 +/- 3/1 mm Hg; P < 0.01) and albuminuria (392 +/- 1.4 microns/min; P < 0.01), and the rate of decline in GFR was 4.4 +/- 0.7 mL/min/yr, in contrast to previous reports of 10 to 14 mL/min/yr (natural history). Univariate analysis revealed a significant correlation between the rate of decline in GFR and mean arterial blood pressure (r = 0.58, P = 0.01), albuminuria (r = 0.67, P < 0.01), hemoglobin A1c (r = 0.69, P < 0.01), and serum total cholesterol concentration (r = 0.51, P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of tenidap on the anti-hypertensive efficacy of thiazide diuretics in patients treated for mild to moderate hypertension

1. This randomised, placebo-controlled, double-blind, parallel-group study was conducted to assess the effect of tenidap sodium 120 mg, a novel anti-arthritic cytokine modulating drug, on the hypotensive efficacy of the thiazide diuretics hydrochlorothiazide or bendrofluazide. 2. Twenty-three male and female patients, aged 41-78 years, with mild to moderate, uncomplicated, essential hypertension controlled with thiazide diuretic therapy, received either a single daily dose of tenidap sodium 120 mg or matched placebo for 22 days in addition to their diuretic therapy. Changes between baseline and endpoint in supine and standing systolic and diastolic pressures and pulse rate were compared between treatment groups. 3. Daily treatment with tenidap reduced the anti-hypertensive efficacy of the thiazide diuretics. Blood pressure tended to increase marginally and the increase in mean standing diastolic pressure observed with tenidap was significantly greater than the change in the placebo group. All pressures tended to decrease in the placebo group and all endpoint measurements were within 7 mm Hg of baseline in both groups. 4. Treatment-related side effects of mild to moderate severity were reported in two subjects receiving tenidap, but in neither case was treatment discontinued. Two subjects receiving placebo also experienced side effects considered to be treatment-related and both were withdrawn from the study. 5. The results of this study suggest that tenidap may be given to patients treated for mild to moderate essential hypertension controlled with thiazide therapy; however, the patient's blood pressure should be regularly monitored.

Enalapril versus bendroflumethiazide in type 2 diabetes complicated by hypertension

In a double-blind, double-dummy, randomized, multi-centre study, the effects of bendroflumethiazide vs. enalapril on blood pressure, glycaemic control, lipoprotein concentrations and albuminuria were compared in non-proteinuric, hypertensive type 2 diabetic patients; they were treated for 20 weeks with either bendroflumethiazide 2.5-5.0 mg (n = 59) or enalapril 10-20 mg (n = 55). Age, fasting plasma glucose, HbA1c and BMI were similar in the groups. Systolic and diastolic blood pressure were reduced in both groups. Bendroflumethiazide was accompanied by minor but significant elevations in fasting plasma glucose and serum C-peptide. HbA1c was increased during both treatments. Lipoproteins and urinary albumin/creatinine ratio were stable. Bendroflumethiazide caused a decrease in serum potassium and an increase in serum urate. No significant correlations were observed between the decline in blood pressure and changes in the metabolic risk factors. Baseline levels of age, sex, BMI, blood pressure or urinary albumin/creatinine ratio were not related to changes in blood pressure, metabolic parameters or urinary albumin/creatinine ratio.

The Hypertension in the Very Elderly Trial (HYVET). Rationale, methodology and comparison with previous trials

The Hypertension in the Very Elderly Trial (HYVET) is a multicentre, open, randomised, controlled trial. The aim of this trial is to investigate the effect of active treatment on stroke incidence in hypertensive patients over the age of 80 years. Secondary end-points include total cardiovascular mortality and morbidity. Entry criteria include a sustained sitting systolic blood pressure of 160 to 219mm Hg plus a sustained sitting diastolic pressure of 95 to 109mm Hg. Also required is a standing systolic blood pressure of at least 140mm Hg. Patients must give their informed consent, and be free of congestive heart failure requiring treatment, gout, renal failure or a recent cerebral haemorrhage. Patients are to be randomised to 3 groups-(i) no treatment; (ii) treatment with a diuretic [bendroflumethiazide (bendrofluazide)]; or (iii) treatment with an angiotensin converting enzyme (ACE) inhibitor (lisinopril). Starting dosage for bendroflumethiazide and lisinopril is 2.5 mg/day. In order to achieve goal sitting systolic and diastolic blood pressures (< 150/80 mm Hg), a doubling of the dosage is allowed. Furthermore, slow release diltiazem (120 mg/day increasing to 240 mg/day if required) may be added to the medication of the actively treated groups. These drugs have been chosen as inexpensive and appropriate representatives of their therapeutic classes. 700 patients in each group (a total of 2100) will be sufficient to detect a 40% difference in cerebrovascular events between no treatment and active treatment (alpha = 0.01, 1-beta = 0.90). These numbers will also detect a difference in total mortality of 25% and in cardiovascular mortality of 35%. The pilot phase of the trial has been started with support from the British Heart Foundation. Centres which are interested in taking part should contact C.J. Bulpitt or any of the other authors.