Modern trends in the treatment of hypertension

The main problem of treatment of hypertension in this country as well as abroad is the fact that only less than one quarter of hypertensive patients are treated effectively and have thus normal blood pressure readings. More effective treatment of hypertension is thus one of the main tasks of health care systems in different countries. The objective of treatment of hypertension is to achieve a normal blood pressure. Evidence has been provided that diuretics and beta-blockers markedly reduce cerebrovascular and cardiovascular mortality, in particular in the elderly. ACE inhibitors are the drugs of choice in patients with heart failure or asymptomatic left ventricular dysfunction and in patients with diabetic nephropathy. Unsuitable for treatment of hypertension are short acting calcium channel blockers, in particular nifedipine. On the other hand, long-acting calcium channel blockers reduce the cerebrovascular mortality in elderly hypertensive patients. A number of questions still remain the subject of research: a) should diastolic pressure be reduced to values lower than 90 mm Hg; so far it is necessary only in hypertensive subjects with diabetes mellitus and in juvenile hypertensives; b) is the influence of new groups of antihypertensive drugs, in particular calcium channel blockers, similar, better or worse than that of diuretics and beta-blockers in the prevention of cardiovascular and cerebrovascular morbidity and mortality?; c) is it wise to recommend acetylsalicylic acid also to hypertensive patients without clinical signs of IHD or atherosclerotic affection of other vessels?; d) what is the value of combined antihypertensive and hypolipidaemic pharmacological treatment? Will this combination be not much more valuable in the prevention of IHD?; e) is the prognosis of hypertensive subjects with left ventricular hypertrophy better when ACE inhibitors are used as compared with other antihypertensive drugs?; f) do ACE inhibitors influence the prognosis of diabetic patients more favourably than beta-blockers?     

Predictors of renal and cardiovascular mortality in patients with non-insulin-dependent diabetes: a brief overview of microalbuminuria and insulin resistance

Both microalbuminuria and insulin resistance are present at some stage in the natural history of non-insulin-dependent diabetes mellitus (NIDDM). Microalbuminuria predicts both progression to endstage renal disease and an increase in cardiovascular mortality compared to diabetic patients without microalbuminuria. Conversely, microalbuminuria is not a strong predictor of either renal or cardiovascular mortality in hypertensive nondiabetic subjects. This difference in risk may relate to the presence of glycated albumin in patients with diabetes. Glycation of albumin occurs because of persistent hyperglycemia. Glycated albumin is directly toxic to both renal and vascular tissue through stimulation of reactive oxygen species by both renal and immune protective cells. Blunting the rise in microalbuminuria with either aggressive blood glucose control or angiotensin-converting enzyme (ACE) inhibition, early in the course of the disease, markedly reduces renal mortality. In contrast to microalbuminuria, which is a reflection of renal injury, insulin resistance is a genetically determined problem that directly relates to peripheral glucose utilization. In most cases, insulin resistance is phenotypically expressed as diabetes as a result of environmental factors such as obesity. Insulin resistance is associated with an increased risk for development of both hypertension and NIDDM as well as atherosclerosis. Diabetic or hypertensive subjects with insulin resistance have an increased risk of cardiovascular but not renal mortality. Sustained weight loss is the best way to reduce insulin resistance and arterial pressure. Additionally, alpha blockers, more than other antihypertensive agents reduce insulin resistance. This class of drugs, however, has not been shown to reduce either microalbuminuria or overall cardio-renal mortality.     

Arterial hypertension: current large therapeutic trials

In this review, the design and objectives of ongoing clinical trials in essential hypertension are discussed along with the main results obtained from previously published therapeutic trials. In a meta-analysis of 14 of the major primary prevention trials in hypertension, the difference in diastolic blood pressure between the intervention groups and the control groups was only 5-6 mmHg. This difference was associated with significant reductions in all stroke events (42 per cent), all coronary heart disease events (14 per cent) and in cardiovascular mortality (21 per cent). In elderly hypertensive patients, available studies have shown that antihypertensive treatment reduces the incidence of non-fatal cardiovascular events without significantly modifying cardiovascular mortality. Most of these results were obtained with beta-blockers or diuretics. Despite official recommendation as first line monotherapy, none of the three new antihypertensive classes has been shown to have beneficial effects on hard primary endpoints such as cardiovascular morbidity and mortality. Several ongoing large scale randomized controlled trials vs. beta-blockers or diuretics are addressing this important issue. Moreover, other effects of antihypertensive treatment such as the 'J-curve phenomenon', the rate of change in the carotid wall thickness or the exact beneficial effects in elderly patients are being investigated in some of these studies.     

Hemodynamic theory of progressive renal disease: a 10-year update in brief review

Experimental studies have suggested that glomerular hypertension is ultimately damaging to the kidney. Prevention of glomerular hypertension by dietary protein restriction or antihypertensive therapy lessens glomerular injury in several experimental models of chronic renal disease. Glomerular hypertension and hyperfiltration also occur in humans with diabetes mellitus, solitary or remnant kidneys, and various forms of acquired renal disease. Clinical studies are beginning to show that dietary protein restriction and antihypertensive therapy may slow progression in these disorders. Large multicenter trials are currently under way to better define the effects of these therapeutic maneuvers on the progression of chronic renal disease.     

How far should blood pressure be reduced in diabetic hypertensive patients?

EPIDEMIOLOGY OF DIABETES: Diabetes mellitus and arterial hypertension are closely related diseases that strongly predispose an individual to atherosclerotic cardiovascular disease and to renal failure. High blood pressure is twice as frequent in diabetics compared with the general population, and often precedes and contributes to the development of diabetic nephropathy. The prevalence of coexisting arterial hypertension and non-insulin-dependent diabetes mellitus (NIDDM) is increasing as populations age, giving an increased prevalence of both diseases. TREATMENT OF HYPERTENSIVE DIABETIC PATIENTS: The goal of treating arterial hypertension in diabetic patients is to prevent death and disability associated with high blood pressure. In addition, other reversible risk factors for cardiovascular disease, seen so frequently in hypertensive diabetics, also need to be addressed. The optimal goal of blood pressure control in diabetics has not been established, but there are indications that it should be lower than the 130/85 mmHg systolic/diastolic pressure recommended by current guidelines. In the presence of multiple associated risk factors, most guidelines suggest a threshold for intervention of > or = 140/90 mmHg. In particular, in hypertensive diabetic patients intervention must be early and aggressive.     

Hypertension and endstage renal disease

OBJECTIVE: To review current literature regarding the development of hypertensive renal disease, its epidemiology, and its pathophysiology. This review focuses on strategies to slow or halt the progression of endstage renal disease (ESRD) in hypertension, including the role of blood pressure control, different types of antihypertensive agents, early treatment, and dietary considerations. DATA SOURCES: Information was retrieved from searching the MEDLINE database for articles consisting of epidemiologic studies, clinical studies, and review articles pertaining to hypertension and ESRD. Information also was obtained from the US Renal Data System annual data reports. STUDY SELECTION: Emphasis was placed on clinical trials in the English language addressing issues in hypertension and ESRD. Clinical trials reporting relationships between blood pressure control and ESRD, as well as those comparing different antihypertensive agents, were evaluated. DATA EXTRACTION: The methodology and results from clinical trials were evaluated. Studies were assessed according to the measures of renal function used, baseline data collected, degree of blood pressure control, and antihypertensive therapy. DATA SYNTHESIS: Clinical trials including patients with essential hypertension, diabetes mellitus, and renal insufficiency of various etiologies were evaluated. The recommendations from these evaluations were based on study design and the types of populations used (i.e., blacks vs. whites, diabetics vs. nondiabetics). CONCLUSIONS: Blood pressure control is currently the most important strategy to slow or halt the progression of renal insufficiency in hypertensive individuals. Whether specific antihypertensives are renal protective is still controversial, but results from clinical trials are promising.     

Coexistence of both oleosin isoforms on the surface of seed oil bodies and their individual stabilization to the organelles

Increased urine albumin is associated with atherosclerotic disease and predicts cardiovascular morbidity and mortality in nondiabetic populations. This finding is frequently postulated to reflect the impact of atherosclerotic damage on glomerular and systemic capillary permeability, an interesting but as yet untested hypothesis. The transcapillary escape rate of albumin (TERalb, the 1-hour decline rate of intravenous 125I-albumin, a measure of capillary macromolecular permeability), albuminuria, lipid levels, echocardiographic wall thickness, and insulin responses to oral glucose were measured in 30 untreated dipstick-negative lean men and clinically stable atherosclerotic peripheral vascular disease; tolerance to oral glucose was a requirement for inclusion in the study. Because hypertension per se might influence TERalb, the sample included either normotensive (n=18, 118+/-6/72+/-7 mm Hg) or hypertensive (n=12, 141+/-7/84+/-6 mmHg by 24-hour blood pressure monitoring) arteriopathic patients; 11 normal age- and gender-matched subjects (121+/-7/76+/-5 mmHg) were used as control subjects. TERalb was higher in patients (10.7+/-3.2 versus 7.4+/-1.7%/h, P<0.013), a difference that persisted after postload glucose, insulin, and lipid levels were accounted for by covariance analysis; atherosclerosis and hypertension together did not further impair vascular permeation to albumin. In contrast with TERalb, albuminuria was elevated only in the hypertensive subgroup; the 2 variables showed no relationship, even when the data were analyzed separately in normotensive and hypertensive subgroups. Urine albumin correlated positively with 24-hour blood pressure and wall thickness. Thus, systemic capillary permeability is altered in nondiabetic atherosclerotic patients independently from blood pressure levels, but this abnormality is not reflected by proportionate changes in albuminuria.     

Effect of antihypertensive treatment on urinary albumin excretion, glomerular filtration rate, and renal plasma flow in patients with essential hypertension

In 20 patients with essential hypertension the urinary albumin execretion, glomerular filtration rate (GFR),and renal plasma flow (RPF) were examined before and after antihypertensive treatment. Albumin excretion measured by radioimmunoassay was increased before treatment, and there was a significant fall during treatment. In patients responding well to therapy (diastolic pressure below 100 mm Hg), albumin excretion was significantly lower than in patients responding poorly to therapy. There was a positive correlation between albumin excretion before treatment and diastolic pressure during treatment, indicating that the albumin excretion rate may be used to predict the result of antihypertensive treatment. Patients with excretion rates below 25 mug/min generally respond well to the treatment used. No definite changes in GFR and RPF were found during treatment, and there was no correlation between albumin excretion and GFR and RPF. It is suggested that the increased albumin excretion in essential hypertension is due both to functional and morphological alterations in the glomerulus, namely increased glomerular filtration pressure and vascular damage.     

Microalbuminuria and its relation to cardiovascular disease and risk factors. A population-based study of 1254 hypertensive individuals

Microalbuminuria has been proposed as a potential atherosclerotic risk factor in hypertensive individuals. The aim of this cross-sectional population study was to analyse whether microalbuminuria is related to a higher prevalence of cardiovascular disease, and a more atherogenic risk profile, and reversely related to the use of antihypertensive drugs. In a major health screening at the State University Hospital in Copenhagen, including urinary albumin excretion, glomerular filtration rate, blood pressure (BP), electrocardiogram, body mass index, plasma lipoproteins, fibrinogen, and albumin, and information regarding a history of acute myocardial infarction, smoking, and antihypertensive drugs, 1254 participants without diabetes mellitus or renal/urinary tract disease had arterial hypertension. Age range was 30-70 years. Microalbuminuria (nocturnal urinary albumin excretion >15 microg/min) occurred in 5%, and cardiovascular disease (previous acute myocardial infarction or electrocardiographic Q-waves) also in 5% of the study population. Microalbuminuric hypertensive subjects were characterized by higher age and systolic BP, and a male predominance, as compared to normoalbuminuric hypertensive subjects. The frequency of cardiovascular disease was similar in the two groups. In contrast, when analysed as a continuous variable, a one unit increase in the logarithmically transformed urinary albumin excretion significantly increased the likelihood of cardiovascular disease (odds ratio [95% confidence interval] 1.32 (1.02-1.70); P < 0.05), and this relation was independent of age, sex, and conventional atherosclerotic risk factors. Participants who were effectively treated with antihypertensive drugs did not have a lower urinary albumin excretion than insufficiently treated or untreated participants. It is concluded that slightly elevated albumin excretion in the urine is not only a pressure-dependent functional phenomenon in the glomerular vessel walls, but associated with permanent atherosclerotic abnormalities in the entire vascular system.     

Heart, brain and hypertension

Hypertension is one of the most important cardiovascular risk factors. Without therapy hypertension leads to stroke, coronary heart disease with angina pectoris and myocardial infarction, kidney failure and/or peripheral vascular disease. The association between blood pressure and these cardiovascular complications can be demonstrated over the entire blood pressure range. The risk of stroke, myocardial infarction, renal failure or peripheral vascular disease increases with increasing blood pressure. Additional cardiovascular risk factors such as hyperlipidemia, smoking and diabetes involve a further increase in risk. Today hypertension can be effectively treated. To that end, diuretics, betablockers, ACE-inhibitors or calcium antagonists can be used. Alpha receptor antagonists and angiotensin AT1 receptor antagonists are also of value. The antihypertensive effectiveness of these drugs is comparable but may vary in individual patients. During antihypertensive therapy, a reduction in cerebrovascular and cardiac complications has been demonstrated for alpha methyldopa, diuretics and betablockers. In these studies, fatal and non-fatal strokes were reduced by 42%, while the reduction in cardiac events was less pronounced (14%). The reasons for this greater efficacy of antihypertensive therapy in the cerebral circulation are not clear. Other risk factors may be particularly important in the pathogenesis of coronary artery disease (e.g. genetic factors, hyperlipidemia and others) or hypertensive vascular changes in the coronary circulation may not be as reversible as they are in the cerebral circulation. The well documented correlation between stroke, myocardial infarction and hypertension, as well as the proven efficacy of antihypertensive therapy in preventing cardiovascular events, underscores the importance of effective and sustained blood pressure control in these patients.     

Managing the elderly hypertensive patient beyond blood pressure reduction

ANTIHYPERTENSIVE TREATMENT OF THE ELDERLY: Several prospective, randomized, long-term trials on antihypertensive drug treatment have shown that elderly patients with systolic and diastolic or isolated systolic hypertension benefit from a reduction in blood pressure. Antihypertensive treatment reduces the overall mortality by 20%, cardiovascular mortality by 33%, the incidence of fatal and non-fatal cerebrovascular events by 40% and the complications of coronary heart disease by 15%. In addition, elderly patients have a high risk of overt or latent and asymptomatic cardiovascular diseases. For this reason, not only antihypertensive treatment, but also risk factor modification (such as cholesterol reduction therapy) is, in absolute terms, more beneficial in elderly patients than in middle-aged patients, particularly in patients with concomitant cardiovascular diseases and other risk factors. QUALITY OF LIFE: Although the randomized trials have focused on mortality and morbidity as main endpoints, it is questionable whether longevity is a worthwhile social objective in itself. Quality of life is an important aspect of antihypertensive treatment, since hypertension is generally symptomless while drug therapy may have adverse effects on the quality of life. The frequency of adverse effects is similar in both middle-aged and elderly hypertensive patients, with about 2% of patients per year in both age groups withdrawing from randomized treatment due to objectively assessed adverse effects. The rate of subjectively assessed adverse effects during treatment is also similar in younger and elderly patients. In general, clinical studies have suggested that a blood pressure reduction does not influence the well-being of elderly patients, whether measured in physical, emotional or social terms. Both calcium antagonists and diuretics have shown an age-dependent effect in comparative trials, with a higher blood pressure reduction in elderly than in younger patients. CONCLUSION: Antihypertensive therapy in elderly hypertensives adds longevity and need not compromise quality of life. Although the reduction and normalization of blood pressure is the primary goal, the increased availability of antihypertensive preparations and drugs for treating concomitant diseases and risk factors allows the physician to tailor treatment of the elderly to the needs of the individual patient.     

Nephrosclerosis: current status

Nephrosclerosis is the most typical and widespread renal manifestation of hypertension and can be judged as the pathological hallmark of essential hypertension. Nephrosclerosis is an important and frequent cause of progressive renal disease, however, information in the literature on the risk of developing renal failure in the course of essential hypertension is sparse. Traditionally, nephrosclerosis was thought to result from glomerular ischemia. Alternatively, glomerular sclerosis in hypertension may result from glomerular hyperperfusion or hypertension. Studies in experimental models of renal disease have identified a promising intervention with either Ca antagonists or angiotensin-converting enzyme inhibitors. Application of these therapies to patients with nephrosclerosis should await the results of careful clinical trials.     

Diabetes and hypertension: the bad companions

DIABETES AND HYPERTENSION: Diabetes mellitus and hypertension are interrelated diseases that strongly predispose people to atherosclerotic cardiovascular disease. Hypertension is about twice as frequent in individuals with diabetes as in those without. The prevalence of coexisting hypertension and diabetes appears to be increasing in industrialized nations because populations are aging, and both hypertension and non-insulin-dependent diabetes mellitus (NIDDM) increase with age. An estimated 35-75% of diabetic cardiovascular and renal complications can be attributed to hypertension. ESSENTIAL HYPERTENSION: Essential hypertension accounts for the majority of hypertension in individuals with diabetes, particularly those with NIDDM, who constitute over 90% of those with a dual diagnosis of diabetes and hypertension. Diabetic nephropathy, which occurs after 15 years of diabetes in one-third of those with insulin-dependent diabetes and 20% of those with NIDDM, is an important contributing factor to the development of hypertension in the diabetic. New investigations should focus increasingly on identifying appropriate antihypertensive agents that not only lower blood pressure but also reduce cardiovascular risk and retard the rate of progression of diabetic renal disease.     

Influence of risk factors and pharmacological treatment on mortality in patients with essential hypertension

BACKGROUND: The V JNC consensus stated that although new antihypertensive agents, such as angiotensin converting enzyme inhibitors and calcium channel blockers, are considered safer drugs, there is no firm evidence from large controlled trials that these drugs are associated with a lower cardiovascular mortality. AIM: To study the association between cardiovascular risk factors, blood pressure levels, pharmacological treatment and mortality in a group of hypertensive patients followed at an hypertension outpatient clinic. PATIENTS AND METHODS: Patients with essential hypertension were treated with different antihypertensive medications, according to physicians criteria, and controlled until death or loss from follow up. Causes of death were obtained from hospital records and death certificates. Survival was analyzed using life tables, comparisons between groups of patients were done using chi square or a Cox's proportional hazards model. RESULTS: Three hundred thirty-nine hypertensive patients aged 33 to 80 years old were followed for a mean period of 9.8 +/- 4.9 years. Eighty-six were treated with beta blockers, 64 with diuretics, 133 with calcium antagonists and 56 with ACE inhibitors. Blood pressure dropped similarly with all medications. During follow up, 79 patients died. Life table analysis showed that patients with a history of angina, diabetes or myocardial infarction had higher mortality rates. Similarly, patients treated with beta blockers and diuretics had higher mortality than patients treated with calcium antagonists or angiotensin converting enzyme inhibitors. The proportional hazards model showed that the effect of treatment modality persisted after correction for the other risk factors for mortality. CONCLUSIONS: In this series of hypertensive patients, those treated with beta blockers or diuretics had higher mortality rates than those receiving calcium channel antagonists or angiotensin converting enzyme inhibitors.     

Oxidation of the flavonol fisetin by polyphenol oxidase

The rapid development of endothelin-receptor antagonists has made the endothelin pathway a new therapeutic target in the treatment of cardiovascular diseases, only ten years after the report of its discovery. While the first clinical trials will help to position this new family of compounds in our therapeutic armament for the treatment of essential or secondary forms of hypertension, several preclinical chronic studies already provide a picture of what we can expect from these drugs. Endothelin-receptor antagonists are not effective in all experimental models of hypertension, but those that respond present hypertrophy of small arteries, secondary to a local overexpression of the peptide. Although angiotensin II seems to represent a stimulus for endothelin overexpression in some models, other, as yet undetermined, stimuli are likely in others. Besides their narrow spectrum of antihypertensive activity, endothelin-receptor antagonists may also protect from complications of hypertension by improving end-organ function in a pressure-independent manner. This seems to be the case for the structure and reactivity of resistance arteries, as well as for renal damage. However, it is not clear at this point if cardiac structure and function are improved beyond the benefits produced by blood pressure reduction. The first results in essential hypertensive subjects suggest some degree of efficacy of endothelin-receptor antagonists. Other clinical trials will help to determine if secondary forms of the disease benefit equally or more from this new class of drugs, and if end-organ damage can be reduced beyond blood-pressure reduction.     

Hypertension: are beta-blockers and diuretics appropriate first-line therapies?

OBJECTIVE: To review the existing data on the use of diuretics or beta-blockers as first-line therapy for the treatment of mild to moderate hypertension, and to examine the issues surrounding the impact of these classes as well as the angiotensin-converting enzyme (ACE) inhibitors, calcium-channel blockers (CCBs), alpha-blockers, and alpha-beta-blockers on cardiovascular risk factors and cardiovascular morbidity and mortality. DATA SOURCES: A MEDLINE search of applicable articles on antihypertensive therapies and their impact on morbidity and mortality. In addition, a MEDLINE search of relevant articles regarding cardiovascular risk factors and the influence of the various antihypertensive therapies on these parameters. DATA SYNTHESIS: The literature was evaluated with regard to outcome. Trials examining the impact of antihypertensive pharmacotherapy, primarily with diuretics and beta-blockers, have shown them to decrease the incidence of stroke by 33-50 percent. However, their effect on coronary heart disease has been disappointing, showing only a 14 +/- 5 (mean +/- SD) percent decrease. Examination of numerous clinical trials assessing the impact of the various antihypertensive therapies on cardiovascular risk factors, including blood pressure, plasma lipids, diabetic control/insulin sensitivity, and left ventricular hypertrophy was done. The classes included beta-blockers, diuretics, alpha-blockers, ACE inhibitors, and CCBs; the results show a diversity of effect. Diuretics and beta-blockers tend to worsen cardiovascular risk status, whereas the alpha-blockers, ACE inhibitors, and CCBs all show a beneficial effect. CONCLUSIONS: Diuretics and beta-blockers can effectively reduce cerebrovascular morbidity and mortality, but have a limited effect on reducing cardiovascular disease, especially myocardial infarction. This may be explained, at least in part, by the negative, or lack of positive, effect on individual patients' overall cardiovascular risk status.     

Effect of KATP channel blocker U37883A on renal function in experimental diabetes mellitus in rats

An increase in glomerular filtration rate (GFR) in early diabetes mellitus is considered a risk factor for the development of diabetic nephropathy. Insulin deficiency may increase the activity of ATP-sensitive potassium channels (KATP), which could promote afferent arteriolar vasodilation und thus contribute to glomerular hyperfiltration in early diabetes mellitus. To further elucidate this hypothesis we performed renal clearance experiments in anesthetized rats at 2 and 6 weeks after onset of streptozotocin-induced insulin-treated diabetes mellitus and studied the acute effect of the putative KATP channel blocker 4-morpholinecarboximidine-N-1-adamantyl-N'-cyclohexylhydr ochloride (U37883A) on renal function. In control rats, application of U37883A (1.5 mg/kg i.v. bolus plus 1.5 mg/kg/hr) induced a significant reduction in heart rate, but did not affect or even slightly increased mean arterial blood pressure. Furthermore, U37883A did not significantly affect renal vascular resistance, renal blood flow or GFR, but caused an eukaliuretic diuresis and natriuresis and lowered plasma renin activity. Diabetic rats at both 2 or 6 weeks after streptozotocin exhibited essentially an identical response to U37883A; in particular, RVR and glomerular hyperfiltration remained unchanged. These results show that in both control and diabetic rats, the renal excretory function, renin secretion and pace setting in the heart were sensitiv to U37883A, implying a functional contribution of KATP channel activity. However, in both control and diabetic rats, renal vascular resistance, renal blood flow, or GFR were not altered by U37883A. These results argue against a substantial role for KATP channels in the basal control of renal hemodynamics in both nondiabetic and diabetic rats.     

Does essential hypertension cause progressive renal disease?

In the distant past, terminal renal failure occurred mainly as a result of malignant hypertension. The introduction of effective antihypertensive therapy has made malignant hypertension rare, and researchers have stopped focusing on the kidney's role in their hypertension research. However, recent long-term observational studies have documented an impressive relationship between hypertension and impaired renal function in patients without primary chronic renal disease; elderly and African American individuals with hypertension have the worst prognoses. The hallmark of hypertensive renal injury is thought to be a progressive increase in intrarenal vascular resistance, which may precede changes in renal structure. Because we lack evidence from renal biopsy studies, it is unclear whether an increase in albumin (protein) excretion correlates with these disturbances of renal function and structure. Nevertheless, because urinary excretion of albumin in patients with essential hypertension is related to the risk of cardiovascular complications, its measurement provides important clinical information.     

Secondary prevention of arteriosclerosis

Secondary prevention of arteriosclerosis tries to inhibit progression of the atherosclerotic process. Therapeutic measures focus on modification of cardiovascular risk factors and antithrombotic treatment. Hypercholesterolemia is the main risk factor for coronary artery disease. The risk of a coronary event is correlated to the plasma cholesterol level. Lowering plasma cholesterol results in reduction of vascular morbidity and mortality. Cigarette smoking is the predominant risk factor for peripheral arterial occlusive disease (PAOD). Smoking cessation reduces progression of PAOD and lowers cardiovascular morbidity and mortality. The preventive effect of antihypertensive therapy in hypertensive patients is most pronounced for cerebrovascular events. Antihypertensive measures improve prognosis after stroke and myocardial infarction. The increased cardiovascular risk in diabetics is in part explained by hyperglycemia and hyperinsulinemia, but also depends on coexisting dyslipidemia and hypertension. Intensive treatment of elevated blood glucose levels, dyslipidemia and hypertension are important preventive measures. Aspirin is highly effective in secondary prevention of vascular events. For the coronary arteries, low-dose aspirin is well established. Whether low-dose aspirin is equally effective for reducing progression of arteriosclerosis in the cerebrovascular and in the peripheral vessels is questionable. Ticlopidine serves as an alternative to aspirin; however, neutropenia may occur, which requires supervision of the patient.     

Long-term effects of antihypertensive agents on proteinuria and renal function

BACKGROUND: Although many studies have examined the effects of antihypertensive agents on proteinuria and glomerular filtration rate in patients with kidney disease, many questions remain unresolved. These questions include whether the effects of agents differ, whether their effects are similar in diabetic and nondiabetic patients with renal disease, and whether the effects of any agents are independent of blood pressure reductions. METHODS: We conducted a meta-analysis of studies obtained with MEDLINE and bibliographies from comprehensive reviews but included only investigations with follow-up times of at least 6 months. We combined data (1) in an analysis of randomized controlled trials, (2) in a separate univariate analysis of controlled and uncontrolled trials, and (3) using weighted multiple linear regression. RESULTS: In 14 randomized controlled trials, angiotensin-converting enzyme inhibitors caused a greater decrease in proteinuria (pooled mean [95% confidence intervals], -0.51[-0.68 to -0.35], ln [treatment/control]), improvement in glomerular filtration rate (0.13 mL/min per month [0.10 to 0.16 mL/min per month]), and decline in mean arterial pressure (-4.0 mm Hg [-4.9 to -3.0 mm Hg]) compared with controls. In a multivariate analysis of controlled and uncontrolled trials, each 10-mm Hg reduction in blood pressure decreased proteinuria (regression coefficient [95% confidence interval] -0.14 [-0.22 to -0.06] ln [after/before]), but angiotensin-converting enzyme inhibitors (-0.45 [-0.58 to -0.32]) and nondihydropyridine calcium antagonists (-0.38 [-0.70 to -0.06]) were associated with additional declines in proteinuria that were independent of blood pressure changes and diabetes. Each 10-mm Hg reduction in blood pressure caused a relative improvement in glomerular filtration rate (0.18 mL/min per month [0.04 to 0.31 mL/min per month]), but among diabetic patients there was a tendency for dihydropyridine calcium antagonists to cause a relative reduction in glomerular filtration rate (-0.68 mL/min per month [-1.31 to -0.04 mL/min per month]). CONCLUSIONS: Long-term beneficial effects of antihypertensive agents on proteinuria and glomerular filtration rate are proportional to blood pressure reductions and are similar in diabetic and nondiabetic patients with renal disease. In addition, angiotensin-converting enzyme inhibitors, and possibly nondihydropyridine calcium antagonists, have additional beneficial effects on proteinuria that are independent of blood pressure reductions.