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Biomedical subjects

S G Massry

Publications and source records attributed to S G Massry.

At least 37 records · Page 2Linked to original sources
PubMed1997

Effect of angiotensin converting enzyme inhibition by perindopril on proteinuria of primary renal diseases.

Many primary renal diseases are associated with marked proteinuria resistant to immunosuppressive therapy. Short-term treatment with angiotensin converting enzyme (ACE) inhibitors may decrease proteinuria in these patients, but the long-term effect of these agents on urinary protein excretion is not known. We conducted a double-blind, parallel-design, placebo-controlled study of 1 year duration to evaluate the efficacy of the new ACE inhibitor, perindopril, in reducing proteinuria in patients with nephrotic syndrome due to histologically proven membranous and membranoproliferative glomerulonephritis and focal segmental glomerulosclerosis. Half of the patients treated with perindopril displayed a decrease in urinary protein excretion from 6.1 +/- 1.0 to 1.2 +/- 0.5 g/24 h, and a rise in serum albumin levels. In the placebo group, protein excretion increased modestly and serum albumin level did not change. There was no difference between the responders and nonresponders to perindopril in age, blood pressure, level of creatinine clearance or urinary sodium excretion. However, the degree of proteinuria before treatment with perindopril was significantly (p < 0.01) higher in the nonresponders. In 3 patients in whom the treatment with perindopril was extended for 18-24 months, urinary protein excretion remained below 1 g/24 h. The data show that perindopril: (1) is an effective agent in the treatment of proteinuria of primary renal diseases; (2) the effect is sustained for up to 2 years if the administration of the drugs is maintained, and (3) this action of perindopril does not depend on the level of sodium intake.

Adult↗
PubMed1997

Impaired Na(+)-H+ exchanger activity of hepatocytes in chronic renal failure.

Available data indicate that cation transport is impaired in many cells in chronic renal failure (CRF). The information on the activity of the Na(+)-H+ exchanger in CRF is variable, and both increased and reduced activity have been reported. The mechanisms through which CRF may exert an effect on the Na(+)-H+ transport are not known. Data exist indicating that PTH inhibits the Na(+)-H+ exchange in kidney and liver, and this action of hormone is most likely due to its ability to raise cytosolic calcium ([Ca2+]i). Therefore, it is possible that excess PTH in CRF may adversely affect the activity of the Na(+)-H+ antiport. This study examines the activity of Na(+)-H+ antiport, intracellular pH (pHi), and buffering capacity of hepatocytes obtained from rats after 6 wk of CRF, from CRF parathyroidectomized animals, and from CRF rats and normal rats treated with verapamil. The pHi and the buffering capacity of hepatocytes were not different in all groups of animals. The activity of the Na(+)-H+ antiport of hepatocytes from CRF animals was significantly (P < 0.01) lower than in hepatocytes from normal rats, CRF parathyroidectomized rats, CRF rats treated with verapamil, and normal rats treated with verapamil, and the values in the latter four groups of animals were not different. This impaired activity of Na(+)-H+ antiport in CRF was observed in all external concentrations of sodium (25, 50, 75, 100, 125, and 150 mM). Thus, CRF altered the kinetics of the transporter in that its Vmax decreased and its K(m) increased. The data show that: (1) CRF is associated with reduction in the activity of Na(+)-H+ antiport in hepatocytes; (2) this defect is due to the state of secondary hyperparathyroidism of CRF; and (3) excess PTH mediates its effect by elevating [Ca2+]i of hepatocytes because treatment of CRF animals with verapamil, which blocks the PTH-induced rise in [Ca2+]i of these cells, prevented the impairment in the activity of the Na(+)-H+ antiport.

Animals↗
PubMed1997

Renal mRNA of PTH-PTHrP receptor, [Ca2+]i and phosphaturic response to PTH in phosphate depletion.

Available data indicate that the mRNAs of the PTH-PTH-related protein (PTH-PTHrP) receptor in the kidney, liver and heart are down-regulated in chronic renal failure (CRF). This is due, in major part, to the elevation of cytosolic calcium ([Ca2+]i) in the cells of these organs. If elevation in [Ca2+]i is indeed the culprit, one should be able to demonstrate down-regulation of the mRNA of the PTH-PTHrP receptor in situations without CRF and with low levels of PTH but with elevated [Ca2+]i. Such a combination of events occurs in phosphate depletion (PD). To test this hypothesis, we examined the [Ca2+]i and the concentration of the mRNA of the PTH-PTHrP receptor in the kidneys from 1, 3 and 6 weeks PD, pair-weighed (PW) rats and PD and PW rats treated with verapamil (PD-V, PW-V). To evaluate the effect of a potential rise in [Ca2+]i on urinary phosphate excretion, we also measured the phosphaturic response to PTH and cAMP in all groups of rats after 6 weeks of the dietary intervention. Renal function was normal in all groups of animals. Blood levels of PTH were significantly (p < 0.01) lower in PD and PD-V after 1 week of PD than in PW and PW-V rats, and they remained low throughout the study. The basal levels of [Ca2+]i in the renal proximal tubular cells were normal after 1 week of PD but rose by the third week of the study and remained elevated by the end of the sixth week. These values were significantly (p < 0.01) higher than those in PD-V, PW and PW-V rats. The concentrations of mRNA of the PTH-PTHrP receptor relative to that of the housekeeping gene G3DPH were significantly (p < 0.01) lower in PD rats after 3 and 6 weeks than in the other three groups of rats. The phosphaturic response to PTH or cAMP was significantly (p < 0.01) greater in PD-V rats than in PD animals. The data show that PD is associated with a rise in [Ca2+]i of renal proximal tubular cells and with down-regulation of PTH-PTHrP receptor in the kidney despite low levels of PTH and normal renal function; normalization of the concentration of [Ca2+]i in PD-V rats was associated with normal expression of mRNA of the receptor. These results provide strong support for the proposal that elevated [Ca2+]i down-regulates the mRNA of the PTH-PTHrP receptor even in the absence of CRF and elevated blood PTH levels. The improvement in the phosphaturic response to PTH and cAMP in PD-V rats is consistent with the notion that the elevated [Ca2+]i of the renal cell in PD rats may interfere with the coupling of PTH receptor-adenylate cyclase system and/or with the postreceptor events responsible for the inhibition of phosphate reabsorption by these agonists.

Animals↗
PubMed1997

Role of elevated cytosolic calcium in the pathogenesis of complications in diabetes mellitus.

Both type I and type II diabetes mellitus are associated with derangements in the regulation of intracellular calcium. Hyperglycemia causes an acute rise in cytosolic calcium ([Ca2+]i) due to increased calcium influx and in certain cells to mobilization of intracellular calcium stores as well. The increase in calcium entry is secondary to the activation of calcium channels inhibitable by verapamil, nifedipine, or amlodipine. The stimulation of these calcium channels is mediated by the activation of G protein(s), leading to stimulation of various cellular pathways. Chronic hyperglycemia is also associated with decreased calcium exit from cells. The combination of increased calcium influx and decreased calcium efflux leads to sustained elevation in basal levels of [Ca2+]i. The latter abnormality may adversely affect cell function. Treatment of diabetic animals with calcium channel blockers normalizes cell [Ca2+]i and prevents and/or reverses the derangements in cellular function.

Animals↗
PubMed1996

Abnormalities in hepatic lipase in chronic renal failure: role of excess parathyroid hormone.

Post-heparin hepatic lipase activity is reduced in chronic renal failure (CRF). This could be due to reduced synthesis, decreased activity, and/or impaired secretion of the enzyme. Further, the factor(s) responsible for such derangements are not elucidated. We examined hepatic lipase metabolism in normal, 6-wk-old CRF rats, CRF-PTX (parathyroidectomized) rats, and CRF and normal rats treated with verapamil (CRF-V, normal-V) using liver homogenate, hepatic cell culture for 8 h, and in vitro liver perfusion. The Vmax of hepatic lipase in liver homogenate was significantly (P < 0.01) reduced and the Km was significantly (P < 0.01) increased in CRF rats, but the values were normal in CRF-PTX, CRF-V, and normal-V rats. Culture of hepatic cells for 8 h was associated with an increase in hepatic lipase activity but the increment in CRF rats was significantly (P < 0.01) lower than that of normal, CRF-PTX, CRF-V, and normal-V rats. Both parathyroid hormone (PTH)-(1-84) and 1-34 inhibited the production of hepatic lipase in cultured cells from normal, CRF-PTX, CRF-V, and normal-V rats. The expression of the mRNA of the hepatic lipase was significantly reduced in CRF animals with the ratio between it and that of house keeping gene G3DPH being 15 +/-3% compared to 40 +/- 1.3% in normal, 44+/-2.9% CRF-PTX, 44 +/- 5.4% in CRF-V, and 39 +/- 3.9% in normal-V rats. Infusion of heparin to the in vitro hepatic perfusion system increased the activity of hepatic lipase in the effluent in all groups of rat except in CRF animals. Infusion of PTH-(1-34) in dose of 10(-6) M into the liver perfusion system inhibited the increase in post-heparin hepatic lipase activity. The data show that in CRF (a) the mRNA of hepatic lipase is downregulated, and hepatic lipase production, activity and release are impaired, (b) that this is due to the state of secondary hyperparathyroidism of CRF since both acute and chronic excess of PTH were associated with these abnormalities, (c) and that prevention of excess PTH by PTX of CRF rats or blocking the effect of PTH by treatment with verapamil corrected the derangement in hepatic lipase metabolism.

Animals↗
PubMed1996

Indapamide is superior to thiazide in the preservation of renal function in patients with renal insufficiency and systemic hypertension.

The long-term effects of indapamide or hydrochlorothiazide on blood presssure and renal function were examined in patents with impaired renal function and moderate hypertension. Both drugs controlled hypertension and blood pressure remained normal during the 2 years of the study. Despite this comparable control of hypertension, indapamide therapy was associated with a 28.5 +/- 4.4% increase in creatinine clearance, whereas treatment with hydrochlorothiazide was associated with a 17.4 +/- 3.0% decrease in creatinine clearance. The results of the study indicate that indapamide is superior to hydrochlorothiazide in the treatment of patients with impaired renal function and moderate hypertension.

Adult↗
PubMed1996

Elevation of cytosolic calcium of rat cardiac myocytes in phosphate depletion.

Phosphate depletion is associated with a rise in cytosolic calcium ([Ca2+]i) of cells and such a derangement is responsible in major part for organ dysfunction in phosphate depletion (PD). Cardiac function is impaired in PD, and it is possible that PD is also associated with rise in [Ca2+]i of cardiac myocytes. The present study examined the effect of PD on [Ca2+]i of cardiac myocytes and explored the mechanisms that may lead to the rise in their [Ca2+]i. The [Ca2+]i of cardiac myocytes began to rise and ATP content began to fall at the third week of PD. After six weeks of PD, the values of [Ca2+]i were significantly higher (P < 0.01) and those of ATP content were significantly lower (P < 0.01) than in control (PW) rats. The Vmax of Ca2(+)-ATPase and Na+,K(+)-ATPase as well as the Na(+)-Ca2+ exchange were significantly lower (P < 0.01) in PD than in PW animals. The data of the present study are consistent with the notion that the rise in [Ca2+]i of cardiac myocytes of PD rats is due to a decrease in calcium efflux out of them.

Adenosine Triphosphate↗
PubMed1996

Nifedipine reverses the abnormalities in [Ca2+]i and proliferation of B cells from dialysis patients.

Both animals and patients with chronic renal failure have impaired B cell function due, in part, to elevated levels of cytosolic calcium ([Ca2+]i). Treatment of HD patients with nifedipine has normalized [Ca2+]i of their polymorphonuclear leukocytes (PMNL) and caused marked improvement in the phagocytic property of the PMNL. This observation may have important clinical implications if this drug exerts a similar effect on other cells such as B cells. We examined [Ca2+]i, proliferation of B cells in response to mitogen, the magnitude of the PTH-induced inhibition of B cell proliferation, and the ATP content of mononuclear cells in 11 hemodialysis patients treated with nifedipine, 12 patients without nifedipine therapy and 11 normal subjects. Serum levels of IgG was also measured in the two groups of patients. There were no significant differences in the age, duration of hemodialysis, blood levels of calcium, phosphorus or PTH (571 +/- 193 vs. 484 +/- 127 pg/ml) among the two groups of patients. The hemodialysis patients without nifedipine therapy compared to those without nifedipine treatment have significantly (P < 0.01) higher levels of [Ca2+]i (120 +/- 1.9 nM vs. 94 +/- 2.2 nM), lower ATP content of mononuclear cells (0.45 +/- 0.06 nmol/10(6) cells vs. 0.68 +/- 0.04 nmoles/10(6) cells), impaired proliferation (5.8 +/- 0.31 x 10(3) cpm vs. 9.8 +/- 0.38 x 10(3) cpm) and smaller inhibition of B cell proliferation by PTH compared to those treated with nifedipine. The values in the patients treated with nifedipine were still modestly but significantly different than in normal subjects. The serum IgG levels of the patients without nifedipine therapy (1210 +/- 71 mg/dl) were significantly lower than those of the patients treated with nifedipine (1594 +/- 81 mg/dl). Thus, the treatment of hemodialysis patients with nifedipine produced marked and significant improvement in the metabolic and functional parameters of B cells despite no changes in blood levels of PTH. These data indicate that the calcium channel blocker, nifedipine, interferes with PTH-induced rise in [Ca2+]i of B cells of hemodialysis patients and consequently improves their metabolism and function. These observations if confirmed in other human cells may provide for a rational therapeutic approach to ameliorate the signs and symptoms of uremia.

Adenosine Triphosphate↗
PubMed1996

Pathways through which glucose induces a rise in [Ca2+]i of polymorphonuclear leukocytes of rats.

Basal levels of [Ca2+]i are elevated in diabetes mellitus. Such an abnormality is most likely due to both increased calcium influx into cells and decreased efflux of this ion out of the cells. The present study examined the cellular pathways that are responsible for hyperglycemia-induced acute rise in polymorphonuclear leukocytes (PMNL), and explored whether such a rise is due to increased calcium entry into PMNL and/or to calcium release from their intracellular stores. There were dose dependent and time dependent rises in the [Ca2+]i of PMNL exposed to high concentrations of glucose. Similar effects were observed when the PMNL were exposed to high concentrations of choline chloride or mannitol. A substantial part of the rise in [Ca2+]i was inhibited when the media contained verapamil or nifedipine or when the PMNL were placed in calcium free media, and the rise in [Ca2+]i was completely abolished when the PMNL were placed in calcium free media containing ryanodine. GDP beta S or pertussis toxin almost completely prevented the glucose-induced rise in [Ca2+]i of PMNL. Rp-cAMP, H-89 or staurosporine produced significant inhibition of the rise in [Ca2+]i. High concentrations of glucose produced a dose dependent shrinkage of PMNL volume over a period of two hours. The volume of PMNL, however, was normal after 24 hours in vitro incubation studies as well as after 1, 2 and 12 days of streptozotocin-induced hyperglycemia in rats. The results are consistent with the formulation that the osmotic activity (cell shrinkage) of the high glucose concentrations activates G protein(s) which then stimulates the adenylate-cAMP-protein kinase A pathway, phospholipase C system and calcium channels. The stimulation of these cellular pathways permits both calcium influx into the PMNL as well as mobilization of calcium from their intracellular stores. Both of these events contribute to the acute rise in their [Ca2+]i. It is possible that the rise in [Ca2+]i is critical for the stimulation of the events that lead to the generation and accumulation of inorganic osmolytes to restore cell volume to normal.

Animals↗
PubMed1996

Effects of parathyroid hormone on hepatocyte pHi and Na(+)-H+ exchanger activity.

Parathyroid hormone (PTH) induces a rise in cytosolic calcium--[Ca2+]i--in many cells. A rise in [Ca2+]i activates the Na(+)-H+ antiport, but PTH inhibits the Na(+)-H+ exchanger in kidney cells. Since PTH induces a rise in [Ca2+]i of hepatocytes, we examined the effect of PTH on their Na(+)-H+ antiport and intracellular pH(pHi). PTH caused an initial activation of Na(+)-H+ exchanger, and this stimulation is amiloride sensitive. The activation of the Na(+)-H+ exchanger was followed by progressive inhibition. This inhibitory effect was dose dependent and occurred over a wide range of external sodium concentrations. PTH also caused a progressive rise in hepatocyte pHi which became apparent after the initial activation of the Na(+)-H+ antiport. This alkalinization of hepatocytes occurred when the cells were placed in sodium or potassium media. These actions of PTH were mimicked by dibutyryl cyclic AMP and 12-o-tetradecanoylphorbol-13-acetate(TPA) and were abolished by H-89 (an inhibitor of protein kinase A), staurosporine (an inhibitor of protein kinase C), and the calcium channel blockers verapamil or nifedipine. The data are consistent with the formulation that PTH, through the activation of the cAMP-protein kinase A pathway, protein kinase C, and calcium channels inhibitable by verapamil or nifedipine, induces a rise in [Ca2+]i of hepatocytes. The latter event causes an initial activation of Na(+)-H+ antiport which is followed by a rise in pHi. Also, PTH may facilitate a Ca2+/2H+ exchange across the hepatocyte membrane and causes an initial and persistent rise in pHi, since the rise in pHi occurred under conditions where Na(+)-H+ antiport is inactive (potassium media). In addition, PTH either directly or through activation of second messenger(s) leads to an increased ammonia content of hepatocytes which could maintain a high pHi. Consequently, the Na(+)-H+ antiport is inhibited in an effort to restore the pHi back to normal.

Ammonia↗
PubMed1996

Acne: a potential side effect of cyclosporine A therapy.

A renal transplant recipient who developed severe acne 6 months after transplantation is described. Maintenance immunosuppression consisted of cyclosporine A (CsA), azathioprine and prednisone. Tapering the prednisone dose to as low as 5 mg/day, in addition to topical tetracycline, Retin-A cream, and systemic antimicrobial therapy failed to control the progression of the skin lesions. Despite therapy with isotretinoin (Accutane), the lesions continued to progress with nodulocystic transformation (acne conglobata) and isotretinoin was discontinued after 4 months. However, the condition continued to worsen with the development of a systemic illness with daily fever, diaphoresis, and depression. High fever (103 degrees F) with shaking chills prompted hospitalization. Withdrawal of CsA resulted in rapid and continuous improvement of the skin lesions. After 12 months of follow-up, the lesions significantly resolved except for residual areas of scarring. No episodes of acute allograft rejection occurred. In conclusion, we suggest that CsA therapy may be associated with the development of acne. Nodulocystic transformation (acne conglobata) may occur despite the use of isotretinoin. Finally, withdrawal of CsA may lead to resolution of the skin disease and should, therefore, be considered as a therapeutic option for severe and treatment-resistant cases.

Acne Vulgaris↗
PubMed1996

Effects of parathyroid hormone on renal tubular proteinases.

Parathyroid hormone (PTH) has been implicated to exert detrimental effects on remnant nephrons in chronic renal failure. The present investigation addressed the influence of PTH on the proteolytic capacity of isolated proximal tubules both from normal (SHAM) and partially nephrectomized rats (5/6-NX). Proteolytic activities were measured either against azocasein (pH 5.4) or with specific fluorogenic peptidyl substrates for individual cysteine proteinases. Azocaseinolytic activity was enhanced 6 weeks after 5/6-NX in tubules (SHAM 19.0 +/- 1.0 vs. 5/6-NX 24.4 +/- 1.5 U/mg protein), while thereafter activities declined progressively with time (5/6-NX 16 weeks: 12.9 +/- 1.2 U/mg protein). This loss in proteolytic activity could almost completely be prevented by parathyroidectomy (PTX) (5/6-NX + PTX 16 weeks: 18.6 +/- 1.1 U/mg protein). By contrast, severe hyperparathyroidism (induced by a low calcium/high phosphorus diet fed for 6 weeks) in 5/6-NX animals resulted in a significant decline in proteolytic activities in remnant tubules (5/6-NX 24.4 +/- 1.5 vs. 5/6-NX+diet 16.4 +/- 1.9 U/mg protein). When specific activities of tubular cathepsins were measured in healthy rats who had received exogenous PTH, each individual cysteine proteinase (cathepsin L: -42%; cathepsin B: -27%; cathepsin H: -51%) was suppressed. This effect of PTH could readily be abolished by the simultaneous administration of verapamil. These results suggest that chronic PTH excess exerts a suppressive effect on tubular proteinase activities both in normal and partially nephrectomized rats. This PTH effect seems to be mediated by an increase of cytosolic calcium.

Animals↗
PubMed1996

Calmodulin content in pancreatic islets and the response of islet membrane Ca2+ ATPase to calmodulin in phosphate depletion.

Chronic phosphate depletion is associated with a reduced Vmax of Ca2+ ATPase in many cells. The mechanisms underlying this phenomenon are not fully understood. One of the regulators of the Ca2+ ATPase enzyme is calmodulin, and the reduced availability of calmodulin or impaired interaction between it and Ca2+ ATPase could be responsible for the impaired activity of this enzyme in phosphate depletion. The present study examined the calmodulin content of pancreatic islets and the effect of calmodulin on the Vmax of Ca2+ ATPase in islets harvested from phosphate-depleted (PD) and pair-weighed (PW) rats. The calmodulin contents in islets from the 2 groups of animals were not different. Basal levels of Vmax of Ca2+ ATPase of islets from PD rats were significantly (p < 0.01) lower than in PW rats. Calmodulin produced a significant (p < 0.01) increase in Vmax of Ca2+ ATPase in islets of PW rats but failed to do so in islets of PD rats. The results indicate that the impaired activity of Ca2+ ATPase in islets of PD rats is not due to the reduced availability of calmodulin but an impaired response of the enzyme to calmodulin is at least partly responsible for the reduction in the Vmax of the enzyme.

Adenosine Triphosphate↗
PubMed1995

Polymorphonuclear leukocytes in non-insulin-dependent diabetes mellitus: abnormalities in metabolism and function.

OBJECTIVE: To determine basal levels of cytosolic calcium ([Ca2+]i) and phagocytic activity in polymorphonuclear leukocytes (PMNLs) from patients with non-insulin-dependent diabetes (NIDDM). DESIGN: Prospective cohort study. SETTING: A university-county hospital. MEASUREMENTS: Cytosolic calcium levels, adenosine triphosphate (ATP) content, and phagocytosis of PMNLs from patients with NIDDM and from controls. INTERVENTION: In patients with NIDDM, we evaluated the effect of treatment with an oral hypoglycemic agent (glyburide) on [Ca2+]i levels, ATP content, and the phagocytosis of PMNLs. PATIENTS: 22 controls and 34 patients with NIDDM were examined. Fifteen patients were studied before and after 3 months of treatment with glyburide. RESULTS: Polymorphonuclear leukocytes from patients with NIDDM showed significantly elevated basal levels of [Ca2+]i (68 +/- 9.6 compared with 43 +/- 4.9 nmol/L; P < 0.01); reduced ATP content (1.30 +/- 0.58 compared with 2.35 +/- 0.45 nmol/10(6) PMNLs; P < 0.01); and impaired phagocytosis (117 +/- 21.0 compared with 145 +/- 17.4 micrograms oil/10(7) PMNLs per minute; P < 0.01) compared with controls. There was a direct and significant correlation (P < 0.01, r = 0.80) between [Ca2+]i levels in PMNLs and serum glucose levels and an inverse correlation between phagocytic ability and [Ca2+]i levels (P < 0.01; r = 0.62) as well as between phagocytic activity and fasting serum glucose levels (P < 0.01, r = 0.54) in patients with NIDDM. Glyburide therapy resulted in significant reduction in fasting serum glucose levels; in PMNLs, this treatment resulted in a significant reduction in [Ca2+]i levels, a significant increase in ATP content, and a significant improvement of phagocytosis. CONCLUSIONS: Patients with NIDDM have elevated [Ca2+]i levels in PMNLs. This abnormality is probably induced by hyperglycemia and is primarily responsible for the imparied phagocytosis seen in these patients.

Adenosine Triphosphate↗
PubMed1995

Blood pressure control, proteinuria, and the progression of renal disease. The Modification of Diet in Renal Disease Study.

OBJECTIVE: To examine the relations among proteinuria, prescribed and achieved blood pressure, and decline in glomerular filtration rate in the Modification of Diet in Renal Disease Study. DESIGN: 2 randomized trials in patients with chronic renal diseases of diverse cause. SETTING: 15 outpatient nephrology practices at university hospitals. PATIENTS: 840 patients, of whom 585 were in study A (glomerular filtration rate, 25 to 55 mliters/min.1.73 m2) and 255 were in study B (glomerular filtration rate, 13 to 24 mliters/min.1.73 m2). Diabetic patients who required insulin were excluded. INTERVENTIONS: Patients were randomly assigned to a usual blood pressure goal (target mean arterial pressure, < or = 107 mm Hg for patients < or = 60 years of age and < or = 113 mm Hg for patients > or = 61 years of age) or a low blood pressure goal (target mean arterial pressure, < or = 92 mm Hg for patients < or = 60 years of age and < or = 98 mm Hg for patients > or = 61 years of age). MAIN OUTCOME MEASURES: Rate of decline in glomerular filtration rate and change in proteinuria during follow-up. RESULTS: The low blood pressure goal had a greater beneficial effect in persons with higher baseline proteinuria in both study A (P = 0.02) and study B (P = 0.01). Glomerular filtration rate declined faster in patients with higher achieved blood pressure during follow-up in both study A (r = -0.20; P < 0.001) and study B (r = -0.34; P < 0.001), and these correlations were stronger in persons with higher baseline proteinuria (P < 0.001 in study A; P < 0.01 in study B). In study A, the association between decline in glomerular filtration rate and achieved follow-up blood pressure was nonlinear (P = 0.011) and was stronger at higher mean arterial pressure. In both studies, the low blood pressure goal significantly reduced proteinuria during the first 4 months after randomization. This, in turn, correlated with a slower subsequent decline in glomerular filtration rate. CONCLUSIONS: Our study supports the concept that proteinuria is an independent risk factor for the progression of renal disease. For patients with proteinuria of more than 1 g/d, we suggest a target blood pressure of less than 92 mm Hg (125/75 mm Hg). For patients with proteinuria of 0.25 to 1.0 g/d, a target mean arterial pressure of less than 98 mm Hg (about 130/80 mm Hg) may be advisable. The extent to which lowering blood pressure reduces proteinuria may be a measure of the effectiveness of this therapy in slowing the progression of renal disease.

Adolescent↗