Confidence vanished or impaired until distrust in the doctor-patient relationship because of COVID-19: Confidence vanished or impaired until distrust: "COVID" in relationship.

Since Hippocrates, the cornerstone of medical practice has been the doctor-patient relationship. The question here is whether these basic principles are still compatible with this unusual COVID-period. This pandemic represents a serious threat to human health, leading to profound changes in behavior in daily life but also in health care. Because of limited resources, health-managers must choose well-balanced solutions able to protect patients and citizens on the one hand and to provide maximal benefit for the society on the other hand. We are going through a moment of rupture that we must acknowledge. Here, we discussed how the doctor-patient relationship could be compromised. Doctors are focused on cares whereas patients are focused on scare. Profound changes occur presently, from the way we present ourselves to each other (including the masks), the poor conditions for physical examination, the mental suffering of both patient and caregiver until sometimes terrible end-of-life conditions. The historical point-of-view helps us to keep in mind previous experiences, and the philosophical perspective helps to contextualize this unedited situation. We should stop briefly our daily rush to put these considerations into perspective to overcome these challenges. Nothing is as effective as trust: let's rebuild it.

[Moderate impairment of renal function and cardiovascular risk]. / Altération modérée de la fonction rénale et risque cardiovasculaire.

The objective of this review is to analyze the relationship between moderate decrease in renal function and cardiovascular (CV) risk and to discuss the potential mechanisms of this association. Prevalence of chronic kidney disease (CKD) is increasing in developed countries. Several studies have shown that a moderate fall in glomerular filtration (GFR) or the presence of microalbuminuria is associated with an increase in CV risk, independently of the traditional CV risk factors. Mechanisms are probably multiple and could include anemia, calcium/phosphate metabolism, inflammation, but also large arteries function. In order to achieve primary or secondary prevention of CV risk, DFG should be estimated from serum creatinine and microalbuminuria should be assessed in every high risk subject. The finding of CKD implies optimal management of all traditional CV risk factors. Future studies are needed in order to evaluate the efficacy and safety of specific therapeutic approach to reduce CV risk in CKD.

[Is masked hypertension an artefact due to the blood pressure measurement method and threshold effects?]. / L'hypertension masquée est-elle un artéfact lié à méthode de mesure et à un effet seuil?

UNLABELLED: From results of office and home measurements of blood pressure (BP), patients can be classified as "hypertensive (HT)", "normotensive (NT)", "office hypertensive (OH)" or "masked hypertensive (MH)" by crossing the classifications obtained from each method. It seems that 9 to 20% of patients could be MH with a prognosis close to HT (SHEAF study). OBJECTIVES: To test the hypothesis that at least one part of the prevalence of MH would be an artefact due to the difference between the methods of measurements (shygmomanometer vs semi-automatic device) and/or due to different definitions of office hypertension (OHT). To determine the impact of different definitions of OHT on the prevalence of MH. METHODS: During the course of a phase IV study, BP was measured with the same semi-automatic device (OMRON 705CP) both at doctor's office (3 measurements at 1-minute intervals) and at home, by the patient himself (3 measurements in the morning and in the evening at 1-minute intervals over the 7 days before the visit). Following definitions were used: Office HT: SBP > or =140 mmHg, DBP > or =90 mmHg, SBP > or =140 mmHg or DBP > or =90 mmHg; Home HT: SBP > or =135 mmHg, DBP> or =85 mmHg, SBP > or =135 mmHg or DBP > or =85 mmHg. Another definition of office HT was used SBP > or =135 mmHg, DBP > or =85 mmHg SBP > or =135 mmHg or DBP > or =85 mmHg. RESULTS: 575 patients were analysed. Results from the two methods of measurements are closed but significantly different (difference for SBP: 3.2 +/- 16.5 mmHg; p < 0.0001; difference for DBP: 1.4 +/- 10.3 mmHg; p = 0.002)

Comparative effect of captopril and nifedipine in normotensive patients with incipient diabetic nephropathy.

In these studies, the effect of a 6-wk treatment by placebo, the calcium-channel blocker nifedipine, or the converting-enzyme inhibitor captopril was assessed in normotensive patients with insulin-dependent diabetes and incipient nephropathy. In response to captopril and nifedipine, arterial pressure decreased slightly and to a similar extent. These drugs resulted in opposite effects on urinary excretion of albumin [i.e., increase in urinary albumin excretion (UAE) by 40% during nifedipine treatment and decrease by 40% during captopril treatment]. No change in UAE was observed in the placebo group. This observation of opposite changes in UAE in the presence of a similar fall in arterial pressure suggests that the effects of captopril and nifedipine on UAE result from some difference in their intrarenal action. The data do not present recommendations for the use or disuse of captopril or nifedipine in such a group of patients and do not allow extrapolation to hypertensive diabetic subjects well controlled by other conventional antihypertensive agents.

[Appropriate medication prescribing in older people]. / Bon usage des médicaments chez le sujet âgé.

Drug-induced adverse effects are one of the main avoidable causes of hospitalization in older people. Numerous lists of potentially inappropriate medications for older people have been published, as national and international guidelines for appropriate prescribing in numerous diseases and for different age categories. The present review describes the general rules for an appropriate prescribing in older people and summarizes, for the main conditions encountered in older people, medications that are too often under-prescribed, the precautions of use of the main drugs that induce adverse effects, and drugs for which the benefit to risk ratio is unfavourable in older people. All these data are assembled in educational tables designed to be printed in a practical pocket format and used in daily practice by prescribers, whether physicians, surgeons or pharmacists.

Is microalbuminuria a marker of early intrarenal vascular dysfunction in essential hypertension?

The relation between basal intrarenal hemodynamics and the renal response to acute inhibition of angiotensin-converting enzyme by captopril and albuminuria was assessed in 106 lean patients with essential hypertension without detectable proteinuria. It was observed that the microalbuminuric group (24.5% of the total population) was characterized by a higher systemic arterial pressure, a lower level of high-density lipoprotein cholesterol, and similar mean values of age, duration of hypertension, glomerular filtration rate, renal plasma flow, filtration fraction, and plasma renin activity when compared with normoalbuminuric subjects. In response to captopril, a significant renal vasodilatation without a change in glomerular filtration rate or a fall in filtration fraction was observed in normoalbuminuric patients only. In contrast, the renal vasodilator response was abolished in microalbuminuric subjects, together with blunting of the rise in plasma renin activity associated with captopril. This occurred despite similar indexes of activity of the endogenous renin-angiotensin system. It is suggested that microalbuminuria may be a marker of early functional or fixed intrarenal vascular dysfunction in never-treated lean patients with essential hypertension.

Contrasting effect of antihypertensive treatment on the renal response to L-arginine.

We assessed the renal hemodynamic response to L-arginine infusion (30 g within 60 minutes) in normotensive subjects, patients with never-treated essential hypertension, and hypertensive patients controlled by long-term (more than 2 years) treatment with or without an angiotensin-converting enzyme inhibitor. The renal vasodilator response to L-arginine observed in normotensive subjects (15 +/- 4% increase in effective renal plasma flow) was abolished in untreated hypertensive patients and restored only in the group treated by angiotensin-converting enzyme inhibition. In the whole population a positive correlation between the change in effective renal plasma flow and the change in urinary cGMP was obtained. It is suggested that abnormalities of the renal nitric oxide pathway not corrected by increased availability of L-arginine and reversible only on long-term treatment by angiotensin-converting enzyme inhibition may underlie the abnormal renal resistance observed in essential hypertension.

Combined renal effects of overweight and hypertension.

The existence of a direct relationship between body mass and arterial pressure is well recognized; however, the effect of obesity on known target organs of hypertension is not clearly understood. We undertook the present studies to assess the influence of obesity on renal function and urinary albumin excretion in 40 normotensive subjects and 80 nevertreated hypertensive patients matched for age, sex, arterial pressure level, and known duration of hypertension in whom an oral glucose tolerance test was within normal limits. Glomerular filtration rate and effective renal plasma flow (expressed as absolute values or values normalized for height) were increased in overweight compared with lean subjects whether normotensive or hypertensive. Glomerular filtration rate was positively correlated with protein intake (as assessed from urinary excretion of urea) and fasting serum insulin level. Urinary excretion of albumin but not IgG and beta 2 microglobulin was higher in hypertensive patients compared with normotensive subjects. The overweight condition clearly enhanced the influence of arterial pressure on albuminuria; in fact, a steeper regression line between albumin excretion rate and arterial pressure was found in overweight compared with lean subjects. These results indicate that the overweight condition is associated with renal hyperfiltration and hyperperfusion, irrespective of the presence of hypertension, and that obesity magnifies the effect of hypertension on albuminuria, thus raising the possibility of an increased susceptibility of obese hypertensive patients to the development of renal damage.

Renal changes associated with cyclosporine in recent type I diabetes mellitus.

The effects of cyclosporine A treatment on arterial pressure and renal function were assessed in 11 young patients with type I diabetes of short duration. Cyclosporine was started at 7.5 mg/kg/day, progressively decreased to 6.3 mg/kg/day at 6 months, and then continued at a lower dose (4.1 mg/kg/day) for an additional 3 months in patients in whom remission of insulin dependency was obtained (n = 6). After 3 months of cyclosporine, a slight but significant increase in arterial pressure (+5.2 +/- 1.5 mm Hg), a rise in renal vascular resistance (approximately 20%), a decrease in glomerular filtration rate (approximately 25%), and a fall in filtration fraction were observed. Such changes were sustained after 6 and eventually 9 months of therapy. The decrease in glomerular filtration rate observed during cyclosporine treatment contrasted with the lack of change in simultaneously estimated creatinine clearance; in fact, the creatinine clearance/glomerular filtration ratio increased from 1.07 +/- 0.05% to 1.33 +/- 0.09% within 3 months of cyclosporine therapy, thus suggesting an enhanced tubular secretion of creatinine. Plasma renin activity and urinary excretion of kallikrein decreased significantly (approximately 50%), whereas plasma aldosterone concentration remained unaltered and plasma concentration of potassium increased during cyclosporine therapy. These changes were observed in the presence of a constant urinary excretion of sodium and potassium and a constant body weight. All parameters returned to pretreatment values within 3 months after cessation of cyclosporine. These results indicate that cyclosporine given for 6-9 months at a moderate dose causes a deleterious but reversible effect on arterial pressure and renal function in young diabetic patients.

Renal characteristics and effect of angiotensin suppression in oral contraceptive users.

-The determinants of the increase in arterial blood pressure associated with the use of estrogen-progestogen oral contraceptives (OC) remain poorly known. The purpose of this study was to assess the renal characteristics and the role of the renin-angiotensin system in women with OC-associated hypertension. Urinary clearances of technetium-labeled diethylene triaminopentaacetic acid (glomerular filtration rate) and 131I-ortho iodohippurate (effective renal plasma flow) were estimated before and after acute administration of captopril in 38 women who became hypertensive while taking OC, 38 non-OC users with essential hypertension matched for age, body mass index, and level of blood pressure, and 38 normotensive women (19 with and 19 without OC). Plasma renin activity was higher in OC hypertensives when compared with those with essential hypertension, but captopril-induced changes in blood pressure and renal hemodynamics and function were similar in both groups. In addition, 24-hours urinary albumin excretion was increased in OC users when compared with nonusers with similar arterial blood pressure. In 13 hypertensive women followed up for 6 months after OC withdrawal, a decrease in plasma renin activity, blood pressure, and glomerular filtration rate but no significant change in urinary albumin excretion and captopril-induced changes in blood pressure and renal hemodynamics were observed. These results indicate that the use of OC is associated with an increased albuminuria and no evidence of a prominent role for the renin-angiotensin system in the maintenance of high blood pressure and renal hemodynamics when compared with non-OC users with essential hypertension.

Nephrotic-range proteinuria in patients with renovascular disease.

PURPOSE: Proteinuria is usually considered a manifestation of glomerular disease. We sought to describe the characteristics of patients with nephrotic-range proteinuria resulting from renovascular disease and to compare them with those of patients who had glomerulonephritis. SUBJECTS AND METHODS: We identified 14 patients with nephrotic-range proteinuria and renovascular disease and compared them with 14 patients who had nephrotic-range proteinuria and biopsy-proven glomerulonephritis, matched for sex, age, and glomerular filtration rate. RESULTS: Patients with renovascular disease were more likely to have known atherosclerotic vascular disease [13 of 14 (93%) vs 3 of 14 (21%), P < 0.0001) and were usually smokers [12 of 14 (85%) vs 3 of 14 (21%), P < 0.0001]. They also had a greater mean (+/- SD) difference between the lengths of their kidneys (29 +/- 10 vs 5 +/- 5 mm, P < 0.001); greater systolic blood pressure (203 +/- 22 vs 174 +/- 25 mm Hg, P < 0.005), plasma renin activity (17 +/- 19 vs 2 +/- 2 ng/mL/h, P = 0.005), and plasma aldosterone concentration (40 +/- 23 vs 11 +/- 10 ng/dL, P = 0.0001); and lower serum potassium levels (3.3 +/- 0.5 vs 3.8 +/- 0.5, P <0.05). Effective renal plasma flow was lower (139 +/- 68 vs 307 +/- 185 mL/min/1.73 m3) and filtration fraction was markedly greater (0.28 +/- 0.04 vs 0.15 +/- 0.07, P = 0.0001) in the patients with renovascular disease. After the oral administration of captopril, blood pressure, effective renal plasma flow, and glomerular filtration rate decreased only among patients with renovascular disease. Of the 14 patients with renovascular disease, 13 had evidence of renal artery thrombosis seen at angiography; 2 patients required dialysis, and 3 others died during follow-up. CONCLUSION: Our findings suggest that the patients with nephrotic-range proteinuria resulting from renovascular disease have distinct characteristics and a poor prognosis.

Glucose tolerance and age-associated decline in renal function of hypertensive patients.

BACKGROUND: Renal function is thought to decrease with age in the general population, but the determinants of this age-associated evolution are poorly understood. Hypertension and diabetes mellitus, two leading causes of chronic renal failure in the elderly, may accelerate this decline. PATIENTS AND METHODS: Urinary clearances of [99mTc]diethylene triaminopentaacetic acid (DTPA) (glomerular filtration rate) and [131I]hippuran (effective renal plasma flow) were assessed in 227 never-treated essential hypertensives aged 20-69 years. Based on the oral glucose tolerance test, the study population consisted of 4% patients with previously unknown diabetes mellitus, 24% with impaired glucose tolerance and 72% with normal glucose tolerance. RESULTS: When the population of 218 non-diabetic subjects was considered, glomerular filtration rate was inversely correlated with age and arterial blood pressure, and positively correlated with effective renal plasma flow, filtration fraction and fasting plasma glucose. In multivariate analysis, age and blood pressure were independent determinants of renal plasma flow, whereas renal plasma flow, age and fasting plasma glucose were independent determinants of glomerular filtration rate. The slope of the regression line relating glomerular filtration rate to age was steeper in patients with impaired glucose tolerance than in those with normal glucose tolerance (-1.52 +/- 0.28 versus -0.65 +/- 0.12, P < 0.01). CONCLUSIONS: These results suggest that impaired glucose tolerance, which is seldom searched for in patients with essential hypertension, may be an important determinant of the age-associated decline in renal function.

Endogenous angiotensin II but not atrial natriuretic peptide modulates the effect of nicardipine on extracellular fluid partition in the rat.

OBJECTIVE: Both atrial natriuretic peptide (ANP) and the dihydropyridine derivative nicardipine lower arterial pressure and induce a shift of plasma fluid from the vascular towards the interstitial compartment. Because some calcium antagonists increase the plasma concentration of ANP, and the effect of ANP on transcapillary fluid shift requires the presence of angiotensin II, we examined the consequences of blocking the ANP and renin-angiotensin systems on the hypotensive and haemoconcentrating effects of nicardipine. METHODS: We evaluated the effects of 45-min 0.1 or 1 micrograms/kg per min nicardipine infusion on arterial pressure and haematocrit in anaesthetized, acutely binephrectomized Sprague-Dawley rats. RESULTS: Infusion of nicardipine resulted in a dose-dependent decrease in arterial pressure. Haematocrit increased by an amount corresponding to the decrease in plasma volume calculated for the relevant dose. In the presence of monoclonal anti-ANP antibodies the nicardipine-induced changes in haematocrit and arterial pressure were not affected. In rats pretreated for 2 weeks with the angiotensin converting enzyme inhibitor enalapril, as well as in rats receiving the angiotensin II receptor antagonist losartan acutely, the nicardipine-induced increase in haematocrit was abolished. In enalapril-treated rats the increase in haematocrit was entirely restored when angiotensin II was infused at a subpressor dose. The nicardipine-induced decrease in arterial pressure was not affected by pharmacological blockade of the renin-angiotensin system. CONCLUSIONS: These results demonstrate that the transcapillary shift of fluid induced by nicardipine is independent of ANP and requires the presence of a functional renin-angiotensin system, whereas its hypotensive action is independent of both ANP and angiotensin II.

Contrasting effects of captopril and nifedipine in normotensive patients with incipient diabetic nephropathy.

Microalbuminuria is a reliable predictor of the eventual development of overt diabetic nephropathy and blood pressure is known to accelerate the course of this nephropathy. In the present studies, the effect of a 6-week treatment by placebo (n = 7), nifedipine (n = 7) and captopril (n = 8) on renal function and urinary excretion of albumin (UAE) was investigated in normotensive, insulin-dependent, diabetic patients with incipient nephropathy (UAE greater than 15 micrograms/min). No change in arterial pressure, renal function or UAE was observed in the placebo group. In response to captopril and nifedipine, mean arterial pressure decreased slightly and similarly in both groups. Glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) increased to a similar extent in the nifedipine group, thus resulting in no change in filtration fraction (FF). In response to captopril, GFR was unchanged whilst ERPF increased; as a consequence FF decreased. Opposite changes in UAE were observed in response to the two treatments; UAE decreased by 40% in the captopril group and by 40% in nifedipine-treated patients. These results indicate that intrarenal changes may be crucial with respect to the effect of therapy on UAE. It is suggested that only agents which reduce FF and probably intraglomerular capillary pressure, such as converting enzyme inhibitors, alter UAE and may possibly interfere with the course of incipient diabetic nephropathy in normotensive patients.

Albuminuria predicts renal functional outcome after intervention in atheromatous renovascular disease.

BACKGROUND: Atheromatous renovascular disease is increasingly recognized as a cause of renal failure; however, the benefit of intervention on renal function outcome cannot be clearly anticipated. OBJECTIVE: To identify reliable predictor(s) of renal functional outcome after revascularization in patients with atheromatous renovascular disease. DESIGN: The effect of percutaneous transluminal renal angioplasty (n = 5) or surgery (n = 18) on glomerular filtration rate ([99mTc]-diethylene triaminopenta-acetic acid clearance) and renal haemodynamics was prospectively assessed in 23 patients with atheromatous renovascular disease (unilateral occlusion in five, unilateral stenosis in four, stenosis of a single kidney in five, unilateral occlusion associated with contralateral stenosis in six, bilateral stenosis in three). Renal function was altered in 18 patients. RESULTS: At early follow-up study (5 +/- 1 months) after intervention, glomerular filtration rate improved (i.e. increased by more than 15%) in six patients, deteriorated in five and remained unchanged in 12 patients. The change in glomerular filtration rate associated with intervention was inversely correlated with the pre-intervention level of urinary albumin excretion and positively with the change in effective renal plasma flow after intervention. Stepwise regression analysis showed that pre-intervention urinary albumin excretion was the only predictor of the glomerular filtration rate response to intervention. At late follow-up study (32 +/- 6 months, n = 13), glomerular filtration rate was stable compared with early follow-up determination in non-proteinuric patients whereas it had deteriorated further in proteinuric patients. CONCLUSION: In patients with atheromatous renovascular disease, albuminuria may be considered as a marker of pre-existing intra-renal vascular and glomerular damage and a reliable predictor of renal functional outcome after intervention.

Long-term improvement in renal function after cyclosporine reduction in renal transplant recipients with histologically proven chronic cyclosporine nephropathy.

BACKGROUND: Chronic cyclosporine (CsA) nephropathy, which has been unequivocally documented in recipients of heart, heart-lung, liver, or bone marrow transplants, as well as in nontransplant situations, usually results in a progressive deterioration of renal function. In this study, we assessed the potential reversibility of chronic CsA nephropathy in renal transplant recipients. PATIENTS AND METHODS: Twenty-three renal transplant patients with biopsy-proven CsA nephropathy associated with long-term CsA administration (27+/-4 months) were followed up for more than 2 years after CsA reduction (18/23 patients) or withdrawal (5/23 patients) and addition of azathioprine. Changes in effective renal plasma flow and glomerular filtration rate were assessed before and 2 years after CsA reduction, whereas serum creatinine, proteinuria, blood pressure, and CsA concentrations were monitored up to 5 years. RESULTS: At 2-year follow-up, glomerular filtration rate increased from 40+/-3 to 47+/-4 (P<0.05) and effective renal plasma flow from 217+/-23 to 244+/-24 ml/min/1.73 m2 (NS). Mean arterial pressure significantly decreased from 98.7+/-2.9 to 93.1+/-2.7 mmHg (P<0.05). There was no significant change in renal vascular resistance, filtration fraction, or albumin excretion. A significant decrease in serum creatinine was also observed during the whole follow-up (73+/-6.5 months). CsA reduction was followed by only one episode of acute reversible rejection; chronic rejection developed in three patients 2 years or later after CsA reduction. CONCLUSIONS: These data suggest that CsA nephropathy participates in graft dysfunction in a small group of renal transplant recipients. In addition, graft dysfunction may be reversible when CsA dosage is reduced early after diagnosis of chronic CsA nephropathy.

Effects of calcium antagonists on adrenaline-induced hypokalaemia.

Long term treatment with nifedipine and nitrendipine, but not verapamil and diltiazem, may reduce plasma potassium levels in hypertensive patients. To test the hypothesis that this effect is related to adrenaline-mediated influx of potassium from the extracellular space, the effect of adrenaline infusions (12.5, 25 and 50 ng/kg/min) on plasma potassium levels was assessed in normotensive subjects after administration of placebo for 4 days, and after administration of nitrendipine, verapamil or diltiazem for 4 days. The adrenaline-induced decrease in plasma potassium levels was enhanced in subjects receiving nitrendipine, but was unaffected in those subjects receiving verapamil or diltiazem. The effects of adrenaline on blood glucose levels, heart rate and blood pressure were uninfluenced in subjects receiving nitrendipine or verapamil, and were blunted in subjects receiving diltiazem. These results suggest that enhancement of the adrenaline-induced intracellular transfer of potassium from the extracellular space is relatively specific to dihydropyridine calcium antagonists.

Effect of preoperative renin-angiotensin system blockade on hypertension following coronary surgery.

Renin-angiotensin system activation is suspected of being involved in postcoronary surgery hypertension, but appears to be useful in maintaining blood pressure during anesthesia and cardiopulmonary bypass. To clarify these points, 19 patients were compared: ten as a control group and nine who received captopril during two days before surgery. Anesthesia was the same for the two groups, and cardiopulmonary bypass ensured nonpulsatile flow rates. Anesthesia induced a slight decrease in the mean arterial blood pressure of the treated group (91.1 +/- 3.3 mm Hg to 83.3 +/- 3.9 mm Hg), which did not occur in the control group (89.9 +/- 5.8 mm Hg to 89.7 +/- 4.9 mm Hg). During cardiopulmonary bypass, the mean arterial blood pressure was maintained at comparable levels in the two groups (65.6 +/- 3.5 mm Hg in the control group, 72.6 +/- 3.0 mm Hg in the treated group), with same pump flow rates. After cardiopulmonary bypass, the mean arterial blood pressure returned nearly to prebypass values. Postoperatively, three patients in the control group and four in the treated group developed hypertension. Thus, preoperative renin-angiotensin system blockade by a converting-enzyme inhibitor did not impair blood pressure regulation during anesthesia and cardiopulmonary bypass, but failed to prevent hypertension following coronary surgery.

Angiotensin-converting enzyme inhibitors versus calcium antagonists in the progression of renal diseases.

In addition to factors such as protein intake or hyperlipidemia, hypertension contributes to the progressive deterioration of renal function in experimental animal models of renal disease, and has a prominent role in the imbalance of intrarenal hemodynamics. Reduction of arterial pressure was shown to alter the course of human chronic renal disease. In patients with diabetic as well as nondiabetic nephropathy, the lowering of proteinuria by angiotensin-converting enzyme inhibitors is greater than that observed with other antihypertensive drugs and appears to be independent of blood pressure control alone, whereas albuminuria may be unaffected or worsened during nifedipine treatment. Angiotensin-converting enzyme inhibitors may afford better protection than conventional treatment at various stages of diabetic nephropathy and prevent the evolution from incipient to overt nephropathy. In patients with nondiabetic renal disease, no unequivocal evidence exists for such a protective effect. In renal transplant recipients receiving cyclosporine, converting enzyme inhibitors and calcium antagonists are equally effective in the control of hypertension and both leave unaltered the glomerular filtration rate. It remains to be demonstrated, using adequate study designs, whether a particular class of agent is superior to another in patients with chronic renal disease.

Contrasting acute effects of captopril and nifedipine on renal function in renovascular hypertension.

In order to assess the determinants of renal function deterioration induced by angiotensin-converting enzyme inhibition (ACEI) in renovascular hypertension, studies were performed in patients with bilateral stenosis (BS; n = 12) and stenosis of a solitary kidney (SK; n = 10). Acute administration of captopril was associated with a consistent fall in glomerular filtration rate in 5 of 12 patients with BS and 8 of 10 with SK. Overall, glomerular filtration rate decreased by 22 +/- 7%, while mean arterial pressure decreased by only 8 +/- 2% and renal plasma flow remained unaltered. The ACEI-induced change in glomerular filtration rate was unrelated to blood pressure or basal plasma renin activity, but it was inversely related to pre-ACEI filtration fraction. In a comparative study conducted in 6 BS and 4 SK patients, acute administration of nifedipine was associated with a change in glomerular filtration rate of 13 +/- 5% and no change in renal plasma flow, despite a marked decrease in mean arterial pressure of 19 +/- 4%. In contrast, in the same patients, glomerular filtration rate fell by 23 +/- 12%, renal plasma flow did not change and mean arterial pressure fell slightly by 7 +/- 3% after ACEI.(ABSTRACT TRUNCATED AT 250 WORDS)