Are aneroid sphygmomanometers accurate in hospital and clinic settings?

BACKGROUND: The aneroid sphygmomanometer is commonly used for the indirect measurement of blood pressure despite significant concerns about its accuracy. Although the mercury sphygmomanometer is highly accurate, there are concerns about the environmental toxicity of mercury. In response to various external pressures to become essentially mercury free, the Mayo Clinic, Rochester, Minn, has replaced many mercury sphygmomanometers with aneroid devices. Since 1993, a maintenance protocol has been in place to ensure proper function and accuracy of these devices. METHODS: We assessed the accuracy of 283 aneroid devices using as the reference standard a digital pressure and vacuum meter that was calibrated using a mercury sphygmomanometer. RESULTS: The mean +/- SD values from the aneroid device in millimeters of mercury at each reference point (at 20-mm Hg intervals from 60 to 240 mm Hg defined by the reference device) were 59.9 +/- 1.9 at 60; 79.9 +/- 1.9 at 80; 100.0 +/- 1.8 at 100; 120.3 +/- 1.8 at 120; 140.7 +/- 1.4 at 140; 160.7 +/- 1.7 at 160; 180.9 +/- 1.3 at 180; 200.7 +/- 5.0 at 200; 221.0 +/- 1.3 at 220; and 240.8 +/- 1.6 at 240 (r = 0.99; P<.001). The values from the aneroid device underestimated those of the reference device by a mean of 0.5 mm Hg (95% confidence interval, 0.3-0.7). Virtually 100% of the values from the aneroid device were within the 4-mm Hg range recommended by the Association for the Advancement of Medical Instrumentation. CONCLUSION: Aneroid sphygmomanometers provide accurate pressure measurements when a proper maintenance protocol is followed.

Percutaneous transluminal renal angioplasty in management of atherosclerotic renovascular hypertension: results in 100 patients.

The long-term effect of percutaneous transluminal renal angioplasty (PTRA) on blood pressure and renal function was assessed in 100 consecutive patients with atherosclerotic renovascular hypertension. Technical success rates (complete plus partial) of a first PTRA averaged 76.2%, 74.1%, and 67.7% for the unilateral (n = 42), bilateral (n = 27), and solitary (n = 31) groups, respectively. Of the technical successes, 59% (43/73) experienced sustained blood pressure benefit (mostly amelioration) during a mean follow-up period of 29 months. Rates of blood pressure benefit were similar in the three groups. Ostial lesions comprised the majority of blood pressure benefit failures. Repeat angioplasty in 14 patients resulted in a 71% technical success rate and a 50% blood pressure benefit rate during a mean follow-up period of 22 months. Long-term stability of mean serum creatinine level was observed after technically successful angioplasty in all three groups. Acute renal insufficiency, which was reversible in all but one patient, complicated 26% of the procedures. Mechanical complications occurred in 14% (20/145) of the arteries acted on; surgical intervention was required in five patients. The mortality rate was 2%. These results suggest that angioplasty is effective in both the long-term management of renovascular hypertension and the preservation of renal function in a large fraction of patients with atherosclerotic renovascular hypertension.

Spurious assessment of acid-base status due to dilutional effect of heparin.

A patient was encountered in whom clinically significant spurious hypocapnia and hypobicarbonatemia were diagnosed resulting from the dilutional effect of excessive amounts of sodium heparin solution in the blood sample. This report presents the relevant data in this patient, summarizes the effects of heparin on the determination of the acid-base status, and provides suggestions for avoiding this important pitfall in clinical practice.

Role of steroid dose in hypertension early after liver transplantation with tacrolimus (FK506) and cyclosporine.

Transplant immunosuppression using either cyclosporine (CsA) or tacrolimus (FK506) leads to renal vasoconstriction and nephrotoxicity. Despite producing similar effects within the kidney and blood vessels, clinical hypertension occurs less frequently with tacrolimus during the first year after transplantation, compared with CsA. To examine the role of steroid dose in early posttransplant hypertension, we measured blood pressure and kidney function in liver transplant recipients treated with tacrolimus and either high-dose (TAC-HI-P, n = 19) or low-dose (TAC-LO-P,n = 20) prednisone, compared with CsA-treated recipients (n = 29) receiving prednisone doses similar to the TAC-HI-P group. At 1 month, hypertension occurred more often with CsA (72%) than with TAC-HI-P (42%, P < 0.05) or TAC-LO-P (30%, P < 0.05). By 4 months after transplantation, hypertension developed in nearly twice as many TAC-HI-P (63%) as TAC-LO-P patients (32%, P < 0.05), with no difference between TAC-HI-P and CsA (86%, NS). Daily prednisone dose at 1 month closely paralleled cumulative steroid dose in the first month in the TAC-HI-P and TAC-LO-P groups. Fourteen of 19 TAC-HI-P patients (74%) required bolus steroids for treatment of rejection within the first month, compared with 3/20 (15%) TAC-LO-P and 10/29 (34%) CsA recipients. Glomerular filtration rate fell from pretransplant levels at 1 month and 4 months to the same degree in CsA, TAC-HI-P, and TAC-LO-P patients. These results demonstrate a central role for steroid dose in the rate of onset of hypertension early after liver transplantation using tacrolimus immunosuppression. Both daily dose and cumulative dosage, including bolus treatment for rejection, may impact on the development of hypertension. Since prevalence rates rise to levels comparable to CsA by 24 months regardless of steroid dose, hypertension after liver transplant may be mediated by different mechanisms at different stages of the posttransplant course.

Current role of automated ambulatory blood pressure and self-measured blood pressure determinations in clinical practice.

OBJECTIVE: To discuss the clinical indications for use of automated indirect blood pressure measurement (ABPM) and self-monitoring of blood pressure. DESIGN: Available equipment, variations in blood pressure, and settings in which ABPM may be useful are reviewed. RESULTS: Measurement of blood pressure in the physician's office may not reflect the usual blood pressure in other nonmedical environments, such as at work, at home, or during sleep. Self-measurement of blood pressure at home and work and ABPM can provide this additional information. These procedures can be useful not only for determining the presence of office or "white-coat" hypertension but also for assessing patients with both borderline hypertension in the office and target organ damage, those with drug resistance, and cases of episodic hypertension or hypotension. ABPM can also be used to assess very abrupt changes in blood pressure (hypertension or hypotension) and changes in heart rate and blood pressure during sleep. An abbreviated (6-hour) ABPM can be used to confirm increased office blood pressure measurements. Thus, a 6-hour ABPM has the potential to decrease the misclassification of subjects with hypertension or normotension and to limit costs. CONCLUSION: Accurate self-monitored blood pressure measurements can be integrated with office blood pressure determinations to assist in the management of many patients with hypertension. Both ABPM and self-monitoring of blood pressure can improve blood pressure control and practice efficiencies.

Noninvasive diagnosis of renovascular disease.

OBJECTIVE: To present the epidemiologic and clinical features of renovascular disease and discuss various diagnostic approaches. DESIGN: We describe the findings in patients with fibromuscular dysplasia or atherosclerotic disease of the renal arteries and review pertinent studies from the literature. RESULTS: Renovascular disease is an important cause of resistant hypertension and progressive renal insufficiency, particularly in the elderly population. Improved blood pressure control and renal function after revascularization have generated intense interest in identifying those patients likely to benefit from this intervention. Fibromuscular dysplasia and atherosclerotic renal artery stenosis account for most cases of renovascular disease. Both entities produce resistant hypertension; the latter is the more common cause of progressive renal insufficiency--occasionally leading to end-stage renal disease. Angiotensin-converting enzyme inhibitor-related renal dysfunction, otherwise unexplained renal insufficiency, and recurrent pulmonary edema are increasingly recognized clinical manifestations of renovascular disease. Traditional screening tests such as intravenous pyelography, intravenous digital subtraction angiography, radionuclide scintirenography, and measurement of the peripheral venous plasma renin activity have limited accuracy for diagnosing renal artery stenosis and do not accurately predict the blood pressure response to revascularization. In comparison, recently developed noninvasive tests such as captopril renography, renal artery duplex sonography, and magnetic resonance angiography seem to be more accurate and, in the case of captopril renography, may be more predictive of the blood pressure response to revascularization. CONCLUSION: Future directions in the area of renovascular disease should include a direct comparison among these new noninvasive diagnostic techniques, with a particular focus on the identification of those patients most likely to benefit from revascularization in terms of both blood pressure control and improved renal function.

Left ventricular diastolic dysfunction in patients with hypertension and preserved systolic function.

OBJECTIVE: To assess prospectively diastolic function in hypertensive patients with preserved left ventricular function, particularly focusing on the limitation of the transmitral flow velocity curve alone to detect diastolic dysfunction. PATIENTS AND METHODS: Comprehensive Doppler analysis was performed in 51 hypertensive patients with preserved left ventricular systolic function. RESULTS: The ratio of the peak early diastolic filling wave velocity to the peak velocity of filling wave at atrial contraction was less than the age-adjusted mean value minus 2 SD in 16 patients, and the other 35 patients had a "normal" transmitral Doppler signal. However, the combined transmitral and pulmonary venous Doppler analysis revealed that 12 of these 35 patients had a "pseudonormal" pattern. The prevalence of diastolic dysfunction was estimated at 31% with use of transmitral Doppler alone but increased to 55% when comprehensive Doppler analysis was used (P < .05). CONCLUSION: The presence of diastolic dysfunction has been frequently overlooked in hypertensive patients with transmitral Doppler analysis alone, and an assessment of diastolic function with a comprehensive Doppler analysis is needed in patients at risk for diastolic dysfunction.

Cyclosporine-induced hypertension after transplantation.

OBJECTIVE: To describe the features and mechanisms of posttransplantation hypertension and suggest appropriate management of the disorder. DESIGN: We review our own experience and reports from the literature on hypertension in cyclosporine A (CSA)-treated transplant recipients. RESULTS: Soon after immunosuppression with CSA and corticosteroids, hypertension develops in most patients who undergo transplantation. The blood pressure increases, which are usually moderate, occur universally because of increased peripheral vascular resistance. Disturbances in circadian patterns of blood pressure lead to loss of the normal nocturnal decline, a feature that magnifies hypertensive target effects. Changes in blood pressure sometimes are severe and associated with rapidly developing target injury, including intracranial hemorrhage, left ventricular hypertrophy, and microangiopathic hemolysis. The complex mechanisms that underlie this disorder include alterations in vascular reactivity that cause widespread vasoconstriction. Vascular effects in the kidney lead to reduced glomerular filtration and impaired sodium excretion. Many of these changes affect local regulation of vascular tone, including stimulation of endothelin and suppression of vasodilating prostaglandins. Effective therapy includes use of vasodilating agents, often calcium channel blocking drugs. Caution must be exercised to avoid interfering with the disposition of CSA or aggravating adverse effects relative to kidney and electrolyte homeostasis. CONCLUSION: Recognition and treatment of CSA-induced hypertension and vascular injury are important elements in managing the transplant recipient.

Rapid adjustment of antihypertensive drugs produces a durable improvement in blood pressure.

Antihypertensive drugs are often initiated and adjusted over a period of weeks to months. It is not clear whether the time and inconvenience of this approach is necessary. We studied whether or not drug adjustment over several days in the context of a physician-nurse team could produce a durable blood pressure benefit according to home blood pressure measurements. Sixty-eight patients (aged 65 +/- 1 years, 47% men) were referred for management of hypertension. Indications for referral were new hypertension (13%), known/controlled hypertension (30%), or known/uncontrolled hypertension (57%). Patients had one to three brief nurse visits/day and were provided with an accurate semiautomated device for self-blood pressure (BP) measurement. Sixty patients provided follow-up data. Group 1 (n = 16) required no change in their preexisting drug regimen during clinic visits, whereas group 2 (n = 44) had drug therapy initiated or adjusted over 4 +/- 1 days. Patients were evaluated at baseline, at dismissal from the clinic, and at latest follow-up (mailed-in report of 42 readings taken over 7 days at 1- to 3-month intervals). Mean follow-up was 11 +/- 0.5 months. Mean BP at baseline, dismissal, and latest follow-up for group 1 were 132 +/- 4/73 +/- 2, 130 +/- 6/70 +/- 2, and 125 +/- 3/73 +/- 3 mm Hg (P = not significant). Mean BP for group 2 at the same intervals were 150 +/- 4/80 +/- 2, 139 +/- 3 (P < .01 v baseline)/75 +/- 2, 133 +/- 2 (P < .01 v baseline and < .05 v dismissal)/74 +/- 1 (P < .01 v baseline). The BP control rate (blood pressures less than 140/90 mm Hg) was 75% in group 2. Drug number/dose remained the same or lower in 87% and 91% of patients during follow-up in groups 1 and 2, respectively. These results suggest that a clinically significant lowering of blood pressure can often be achieved over several days and maintained for up to 1 year. Increased use of rapid drug titration, a physician-nurse team approach, and self-BP measurement at prescribed intervals have the potential to improve BP control rates and reduce the expense and inconvenience associated with the treatment of hypertension.

Hypertension after liver transplantation: a predictive role for pretreatment hemodynamics and effects of isradipine on the systemic and renal circulations.

Hypertension developing after liver transplantation during immunosuppression with cyclosporine A reflects an unusual hemodynamic transition from peripheral vasodilation to systemic and renal vasoconstriction. Although dihydropyridine calcium channel blockers are often administered for their efficacy in promoting vasodilation, some liver transplant recipients report marked symptomatic intolerance to these agents. In the present study we examined systemic and renal responses to isradipine using systemic (thoracic bioimpedance) and renal hemodynamic measurements in 15 liver transplant recipients studied at the time of initial diagnosis of posttransplant hypertension and after 3 months of treatment. Circadian blood pressure patterns were examined by overnight ambulatory blood pressure monitoring before and during antihypertensive therapy. During isradipine administration, blood pressure decreased from 151 +/- 3/91 +/- 2 to 130 +/-3/81 +/- 2 mm Hg (P < .01) without change in renal blood flow (406 +/- 43 to 425 +/- 52 mL/min/1.73m2, P = NS) or renal vascular resistance index (25,674 +/-3312 to 20,520 +/- 2311 dynes x sec x cm(-5)/m2, P = NS). Pre-treatment differences in systemic vascular tone persisted during treatment and predicted the tendency for symptomatic tachycardia and flushing, predominantly in those with hyperdynamic circulations. Twice daily dosing of isradipine was associated with partial and significant restoration of the nocturnal decrease in blood pressure (systolic blood pressure decreased 5.5%, normal 13%), usually absent early after transplantation. Our results demonstrate the ability of hemodynamic measurements to predict the symptomatic response to antihypertensive therapy in the posttransplant setting.

Racial differences in HLA antigen frequency and hypertensive renal failure.

Black patients with hypertension are six times more likely to develop end-stage renal disease than are their white counterparts. To determine if genetic differences associated with the Human Leukocyte Antigen (HLA) system account for racial variation in hypertensive renal failure, we examined antigenic frequencies from a large renal transplant registry. Human Leukocyte Antigen phenotypes from cadaveric renal transplant recipients and donors in the South Eastern Organ Procurement Foundation database from 1982 to 1986 were analyzed. One thousand six hundred four renal transplant recipients with hypertensive renal failure as the cause of end stage renal disease (cases) were compared with 4506 race-matched cadaveric kidney donors (controls). Log-linear models were used to assess the relationship between hypertensive renal failure and prevalence of each HLA phenotype. Bonferroni adjustments of P values were used to correct for multiple comparisons. Comparison of HLA frequencies between blacks and whites with hypertensive renal failure demonstrated that blacks had an increased frequency of HLA-DR3 beyond that normally known to exist between black and white populations. Black cases compared to black controls had an 8.6% increase in HLA-DR3 frequency contrasted with a 1.6% decrease in the frequency of this antigen between white cases and white controls. This absolute 10.2% difference between the races was significant (P = .02) because the control black and white populations had nearly identical frequencies for this antigen. White cases compared to white controls had lower HLA-A1 and B8 frequencies (21.2% v 30.6%, P = .0005 and 13.7% v 22.3%, P = .001, respectively) and a greater HLA-B35 frequency (20.7% v 14.2%, P = .02).(ABSTRACT TRUNCATED AT 250 WORDS)

Loss of nocturnal blood pressure fall after liver transplantation during immunosuppressive therapy.

Hypertension, which develops after organ transplantation during immunosuppression with cyclosporine (CSA), is often associated with a loss of nocturnal decrease in blood pressure. Few data correlate circadian blood pressure patterns before transplant with those observed at fixed time points after transplant, or address the role of alternate immunosuppressive agents such as FK506. FK506 is unrelated structurally to CSA and less often leads to hypertension early after transplant. The present study compared nocturnal blood pressure patterns in patients with end-stage liver disease (ESLD) before transplant to those of transplant recipients receiving either FK506 (0.15 mg/kg/day) plus prednisone or CSA (2 to 3 mg/kg/day) plus prednisone and azathioprine after orthotopic liver transplantation. Overnight ambulatory blood pressure profiles were studied in 13 pretransplant ESLD patients and in 34 patients (FK506: n = 13; CSA: n = 21) treated with different steroid doses (24 +/- 11 mg/day FK506; 34 +/- 3 mg/day CSA), according to protocol, 4 weeks (range, 2 to 7 weeks) after liver transplant. Mean blood pressure and heart rate values from awake and nocturnal 5-h time blocks were compared to 13 normotensive control subjects. Patients with ESLD were normotensive and maintained a normal nocturnal blood pressure fall (125 +/- 3/74 +/- 2 mm Hg awake; 109 +/- 3/60 +/- 2 mm Hg nocturnal). Awake ambulatory blood pressures were higher in CSA patients than in FK506 patients (148 +/- 3/95 +/- 2 v 128 +/- 3/78 +/- 2 mm Hg, respectively; P < .01), despite reduced glomerular filtration rates in both transplant groups. Both immunosuppressive regimens led to a loss of nocturnal blood pressure fall, as compared to ESLD patients or normotensive controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Enalapril in the management of hypertension associated with renal artery stenosis.

Enalapril maleate (MK-421) is a new non-sulfhydryl-containing converting-enzyme inhibitor that has been shown to be effective and well tolerated in patients with essential hypertension. Data on its effectiveness and safety in patients with renovascular hypertension are limited and have involved predominantly short-term observations. This is particularly true with respect to the long-term effects of enalapril on renal function. We report our experience using the combination of enalapril and hydrochlorothiazide (HCTZ) in a group of nine patients with moderate to severe hypertension associated with renal artery stenosis. The enalapril-HCTZ combination successfully controlled blood pressure in seven patients during a six-week period of study. Adverse effects were not noted, and detailed renal hemodynamic studies did not reveal any significant changes of renal plasma flow and glomerular filtration rate during this time interval. Five patients were continued on this regimen for a period of six to 18 months. In this group of patients, the regimen continued to be well tolerated and to provide excellent blood pressure control: glomerular filtration rate was maintained in two patients and variable grades of decrease were noted in three. The mechanism of this delayed renal dysfunction as well as its relationship to enalapril treatment remain unclear. The long-term impact of converting-enzyme inhibition on renal function requires further study.

Cyclosporin-induced hypertension: incidence, pathogenesis and management.

Blood pressure increases soon after administration of immunosuppressive regimens using cyclosporin. Characteristic vascular changes lead to systemic and renal vasoconstriction. Changes in blood pressure are commonly associated with disturbed circadian regulation and may promote the rapid development of target organ injury, including intracranial haemorrhage, left ventricular hypertrophy and microangiopathic haemolysis. The mechanisms underlying this disorder are complex and include altered vascular endothelial function. Vasodilators such as prostacyclin and nitric oxide are suppressed, whereas vasoconstrictors, including endothelin, are increased. Changes in the kidney include vasoconstriction, reduced glomerular filtration and sodium retention. Effective therapy depends upon rigorous blood pressure control by administration of vasodilating agents, with attention to potential interactions with cyclosporin.

Prevalence of ischemic nephropathy in patients with renal insufficiency.

To estimate its clinically unsuspected prevalence among patients with renal insufficiency, renal duplex sonography (RDS) was used to estimate the presence of critical renal artery stenosis (RAS) in that population. Patients, aged 45 to 75 years, with a serum creatinine of greater than or equal to 2.0 mg% but without dialysis dependence, prior renal transplantation, or prior renal artery surgery were considered for RDS. Fifty-three patients who met criteria for study were randomly selected from the Section of Nephrology clinic files and each patient was contacted both by mail and by telephone. Twenty-five patients agreed to RDS, and renal artery anatomy was determined in 21 patients using standardized RDS techniques. These techniques have demonstrated an overall accuracy of 96 and 97 per cent when compared prospectively to conventional angiography during validity analyses in the authors' center. Results of RDS revealed significant findings in 5 of 21 patients (24%). Three patients demonstrated criteria for ischemic nephropathy (IN): one patient had RAS with contralateral renal artery occlusion confirmed by angiography, while 2 patients demonstrated unilateral RAS. An abdominal aortic aneurysm and unilateral hydronephrosis were discovered in the fourth and fifth patients. Evaluation of patient demographic data and functional parameters as predictors of IN revealed that the duration of renal insufficiency at the time of RDS and extra-renal organ-specific atherosclerotic damage were significantly different between the groups with and without IN. The authors preliminary findings suggest that unsuspected ischemic nephropathy may exist in a significant minority of patients with renal insufficiency.

Lymphoma-mimicking peritonitis in a patient on continuous ambulatory peritoneal dialysis (CAPD).

Cloudy dialysate in a patient on continuous ambulatory peritoneal dialysis (CAPD) most commonly reflects an increased number of leukocytes secondary to bacterial peritonitis. In the absence of infection, increased quantities of eosinophils, red blood cells, fibrin, or chyle may produce cloudy dialysate in these patients. We report the case of a CAPD patient presenting with cloudy dialysate and symptoms suggestive of bacterial peritonitis. Analysis of the dialysate revealed no microorganisms. The turbidity of the dialysate was related to an increased number of atypical lymphocytes consistent with a B cell lymphoma. Peritoneal dialysis continued uneventfully despite neoplastic disease within the peritoneum. It is recommended that malignant involvement of the peritoneum be added to the differential diagnosis of cloudy dialysate occurring in CAPD patients.

Emerging clinical roles for ambulatory blood pressure monitoring.

Ambulatory blood pressure monitoring is becoming increasingly popular in the diagnosis and treatment of patients with hypertensive disorders. Widespread clinical use, however, has been limited by a lack of normative data and prospective, controlled clinical studies of its impact on subsequent cardiovascular morbidity and mortality. Particular applications of this technology include the investigation of white coat hypertension and correlation of the components of diurnal blood pressure variation with hypertension-associated target organ damage. Recently, interest has extended to the role of different physiologic states such as pregnancy and aging, as well as racial and other genetic differences, in the development of hypertension and susceptibility to target organ damage, and the study of hypertension associated with diabetes mellitus, renal disease, and organ transplantation. This review summarizes recent studies in these areas in addition to discussing the current clinical indications, limitations, and future research directions of ambulatory blood pressure monitoring.

Radiographic evaluation of the renal vasculature.

Renal artery stenosis is an important cause of hypertension and progressive renal insufficiency. Additionally, there is increasing concern that renovascular disease is a significant, but previously-unrecognized, cause of end-stage renal disease in certain subsets of patients. Advances in revascularization techniques offer a greater opportunity for blood pressure control and for the restoration or preservation of renal function. Accurate imaging of the renal vasculature, however, is essential for the proper selection of those individuals who might best benefit from such intervention. Although conventional or digital subtraction arteriography remains the gold standard diagnostic test, significant advances in non-invasive imaging techniques now offer the clinician several options for the accurate diagnosis of hemodynamically significant renovascular disease. These techniques include captopril renography, duplex ultrasonography, magnetic resonance angiography, and spiral/fast computed tomography. In this review, the advantages and limitations of these imaging techniques are compared and contrasted with an emphasis on their usefulness in screening for renovascular disease. Also reviewed are recent applications of these techniques for measurement of renal function, predicting outcome of revascularization, and the clinical monitoring of patients with renovascular disease managed either medically or by revascularization.

Importance of blood pressure reduction for prevention of progression of renal disease.

Despite reduction of stroke and coronary mortality rates, progression of renal disease to end stage continues to occur with increasing frequency. Recent studies emphasize common pathways of elevated arterial pressures that produce increased glomerular capillary pressures and increase filtered proteins in the urinary space. Such proteinuria, along with activation of the intrarenal renin-angiotensin system, endothelin, and inflammatory cytokines, magnifies progressive renal injury and fibrosis. Malignant forms of hypertension with severe arteriolar injury and proteinuria can be treated effectively with current antihypertensive regimens with improved patient survival. Several recent studies indicate improved renal outcomes in proteinuric diseases, generally regardless of the specific antihypertensive agent. Recent trials of hypertensive subjects with minimal proteinuria demonstrate slower rates of disease progression than that seen in subjects with proteinuria above 1 gram per day. Reduction of arterial pressures, particularly when it leads to reduced proteinuria, can slow the progression of many renal diseases.