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Aims: To investigate whether the degree of albuminuria reduction observed in the ALTITUDE trial is associated with renal and cardiovascular protection, and secondly, whether the reduction in albuminuria was too small to afford clinical benefit., Methods: In a post hoc analysis of the ALTITUDE trial in 8561 patients with type 2 diabetes and chronic kidney disease or cardiovascular disease we examined the effect of albuminuria changes at 6 months on renal and cardiovascular outcomes using Cox proportional hazard regression., Results: The median change in albuminuria in the first 6 months in the aliskiren arm of the trial was -12% (25th to 75th percentile: -48.7_to_ +41.9%) and 0.0% (25th to 75th percentile: -40.2_to_55%) in the placebo arm. Changes in albuminuria in the first 6 months were linearly associated with renal and cardiovascular endpoints: a >30% reduction in albuminuria in the first 6 months was associated with a 62% reduction in renal risk and a 25% reduction in cardiovascular risk compared with an increase in albuminuria. The association between changes at 6 months in albuminuria and renal or cardiovascular endpoints was similar in the two treatment groups (p for interaction >0.1 for both endpoints)., Conclusions: The addition of aliskiren to angiotensin-converting enzyme inhibitor/angiotensin receptor blocker therapy resulted in albuminuria changes that were associated with renal and cardiovascular risk changes. This did not translate into renal or cardiovascular protection because the overall reduction in albuminuria in the aliskiren arm was too small and nearly similar to that in the placebo arm., (© 2015 John Wiley & Sons Ltd.)

Introduction: We recently developed and validated in existing trials a novel algorithm (PRE score) to predict long-term drug efficacy based on short-term (month-6) drug-induced changes in multiple risk markers. To show the value of the PRE score for ongoing and planned clinical trials, we here report the predicted long-term cardio-renal efficacy of aliskiren in type 2 diabetes, which was investigated in the ALTITUDE trial, but unknown at the time this study was conducted., Methods: We established the relation between multiple risk markers and cardio-renal endpoints (as defined in ALTITUDE) using a background database from past clinical trials. The short-term effect of aliskiren on multiple risk markers was taken from the AVOID trial. A PRE score was developed by multivariate Cox analysis in the background population and was then applied to the baseline and month-6 measurements of the aliskiren treatment arm of the AVOID trial to predict cardio-renal risk. The net risk difference at these time-points, after correction for placebo effects, was taken to indicate the estimated long-term cardio-renal risk change., Results: Based on the PRE score, we predicted that aliskiren treatment in ALTITUDE would confer a relative risk change of -7.9% (95% CI -2.5 to -13.4) for the cardio-renal endpoint, a risk change of -5.1% (-1.2 to -9.0) for the CV endpoint and a non-significant risk change of -19.9% (-42.1 to +2.1) for the renal endpoint., Conclusions: PRE score estimations suggested that aliskiren has only a marginal additive protective effect on cardio-renal endpoints. These predictions were validated by the results of the ALTITUDE trial, confirming the potential of the PRE score to prospectively predict drug efficacy on cardio-renal outcomes.

Inhibition of renin with an active site inhibitor, aliskiren, lowers blood pressure (BP) in diabetic patients. Here, we studied the time course of the antihypertensive and antiproteinuric effect of renin inhibition in 15 patients with type 2 diabetes and elevated urinary albumin/creatinine ratios (UACRs) to check whether aliskiren can decrease proteinuria. After a 4-week washout of previous medications, patients received aliskiren and furosemide daily for 28 days followed by a 4-week withdrawal period. Twenty-four-hour BPs were measured at baseline throughout treatment and withdrawal periods. The UACR was significantly reduced after 2-4 days of treatment with another significant reduction after 28 days. Systolic blood pressure (SBP) was significantly lower after 7 days with no further reduction after 28 days. The BP returned toward baseline 3 days after withdrawal, whereas the UACR was still significantly reduced compared with baseline 12 days after withdrawal. Our study shows that aliskiren reduced 24 h SBP, and this was associated with a reduction in albuminuria in type 2 diabetic patients.

Aims/hypothesis: We explored the impact of baseline left ventricular hypertrophy (LVH) and losartan treatment on renal and cardiovascular (CV) events in 1,513 patients from the Reduction of Endpoints in NIDDM with the Angiotensin II Antagonist Losartan (RENAAL) trial, which studied the effects of losartan on the progression of renal disease and/or death in patients with type 2 diabetes and nephropathy., Materials and Methods: LVH was assessed using ECG criteria (Cornell product and/or Sokolow-Lyon voltage). The risk of renal or CV events was determined by a proportional hazards model fit with treatment allocation and presence of LVH. Covariates at baseline included age, sex, systolic BP, mean arterial pressure, pulse, proteinuria, serum creatinine, albumin and haemoglobin., Results: A total of 187 subjects (12%) had LVH at baseline. Treatment with losartan resulted in a significant decrease in the Cornell product (-6.2%) and Sokolow-Lyon voltage (-6.3%). LVH was shown to be significantly associated with the primary endpoint, which was a composite of doubling of serum creatinine (DSCR), endstage renal disease (ESRD) or death (hazard ratio [HR]=1.44, p=0.011), as well as with the composite renal endpoint of DSCR/ESRD (HR=1.42, p=0.031) and CV events (HR=1.68, p=0.001). Losartan treatment of patients with LVH decreased the CV as well as renal risk to a level similar to that of patients without LVH., Conclusions/interpretation: In patients with type 2 diabetes and nephropathy, LVH is associated with significantly increased risk of CV events and the progression of kidney disease. Importantly, in patients with LVH, losartan reduced the CV as well as the renal risk to a level similar to that seen in subjects without LVH.

Background: Impaired autoregulation of the glomerular filtration rate (GFR) implies disturbances in the downstream transmission of the systemic blood pressure into the glomerulus, leading to capillary hypertension or hypotension dependent of the level of blood pressure. The impact on renal autoregulation of different antihypertensive drugs in animals has been elucidated, whereas information in humans is lacking., Methods: A randomized, double-blind crossover study with candesartan cilexetil 16 mg o.d. and placebo was performed in 17 hypertensive type 2 diabetic patients without nephropathy. Each treatment arm lasted four weeks. On the last day, GFR (single shot [51Cr] EDTA plasma clearance technique for 4 hours) was measured twice between 8 a.m. and 5 p.m., first without clonidine and then after an intravenous injection of clonidine 75 microg. Blood pressure (Takeda TM2420, A&D, Tokyo, Japan) was measured every ten minutes, and the urinary albumin excretion rate (UAER) was measured by ELISA during each GFR determination., Results: Candesartan induced a mean (SE) reduction in mean arterial blood pressure (MABP) of 6 (2) mm Hg (P < 0.02) and had a tendency to reduce UAER (P = 0.07), while GFR remained unchanged (95 vs. 93 mL/min/1.73 m2). Clonidine reduced MABP with 17 (2) versus 16 (1) mm Hg during placebo versus candesartan 16 mg o.d., respectively (NS). GFR diminished in average from 95 (3) to 92 (4) mL/min/1.73 m2 with placebo (NS), and from 93 (3) to 89 (4) mL/min/1.73 m2 during treatment with candesartan (NS). The mean difference (95% CI) in the changes in GFR between the examination with placebo and with candesartan was 0.1 (-5.5 to 5.8) mL/min/1.73 m2 (NS)., Conclusion: Candesartan reduces blood pressure without adversely altering the preserved ability to autoregulate GFR in hypertensive type 2 diabetic patients without nephropathy.

Introduction: Microalbuminuria and hypertension are risk factors for the development of diabetic nephropathy. Blockade of the renin-angiotensin system reduces progression to diabetic nephropathy in type 1 diabetic patients, whereas similar data are lacking for hypertensive type 2 diabetic subjects. We evaluated the renoprotective effect of an angiotensin II receptor antagonist, irbesartan, in hypertensive type 2 diabetic patients with microalbuminuria., Material and Methods: Five hundred and ninety hypertensive type 2 diabetic patients with microalbuminuria were enrolled in this multinational, randomised, double-blind, placebo-controlled study of irbesartan 150 mg/daily or 300 mg/daily or matching placebo for two years. The primary outcome was time to progression to diabetic nephropathy, defined as a persistent overnight albuminuria > 200 micrograms/min and at least a 30 per cent increase from baseline., Results: Baseline characteristics in the three groups were similar. Ten patients (5.2 per cent) receiving irbesartan 300 mg and 19 patients (9.7 per cent) receiving irbesartan 150 mg daily reached the primary end point, as compared to 30 (14.9 per cent) patients on placebo (hazard ratio 0.30 [95 per cent confidence interval 0.14 to 0.61], p < 0.001 and 0.61 [95 per cent confidence interval 0.34 to 1.08] p = 0.08), respectively). The average blood pressure throughout the study was 144/83, 143/83, and 141/81 mmHg in the placebo, irbesartan 150 mg and 300 mg group, respectively (p = 0.004 for systolic blood pressure). Serious adverse events were less frequent in the patients treated with irbesartan (p = 0.02)., Discussions: Irbesartan is renoprotective independently of its blood pressure lowering effect in type 2 diabetic subjects with microalbuminuria. It is safe and well tolerated.

Introduction: Diabetic nephropathy is the leading cause of end-stage renal disease. Interruption of the renin-angiotensin system slows the progression of renal disease in type 1 diabetic patients, but similar data are not available for type 2, the most common form of diabetes. We assessed the role of the angiotensin II receptor antagonist, losartan, in type 2 diabetic patients with nephropathy., Material and Methods: One thousand five hundred and thirteen patients were enrolled in this randomised, placebo-controlled study of losartan (50 to 100 mg, once daily) or placebo, in addition to conventional antihypertensive treatment (calcium antagonists, diuretics, alpha- and beta-blockers, centrally acting agents) for a mean of 3.4 years. The primary outcome was the composite of doubling of baseline serum creatinine, end-stage renal disease, or death. Secondary end points included a composite of cardiovascular morbidity and mortality, proteinuria, and the progression rate of renal disease., Results: Baseline demographics in the two groups were similar. Three hundred and twenty-seven patients receiving losartan reached the primary end point, as compared with 359 on placebo (risk reduction = 16 per cent, p = 0.02). Losartan reduced the incidence of doubling of serum creatinine (risk reduction = 25 per cent, p = 0.006) and end-stage renal disease (risk reduction = 28 per cent, p = 0.002), but had no effect on death. Benefits exceeded that attributable to changes in blood pressure. The composite of cardiovascular morbidity and mortality was similar in the two groups, except hospitalisation for heart failure, which was reduced with losartan (risk reduction = 32 per cent, p = 0.005). Proteinuria declined by 35 per cent with losartan (p < 0.001)., Discussion: Losartan conferred significant renal benefits in type 2 diabetic patients with nephropathy and was generally well tolerated.

Background: Diabetic nephropathy is the leading cause of end-stage renal disease. Interruption of the renin-angiotensin system slows the progression of renal disease in patients with type 1 diabetes, but similar data are not available for patients with type 2, the most common form of diabetes. We assessed the role of the angiotensin-II-receptor antagonist losartan in patients with type 2 diabetes and nephropathy., Methods: A total of 1513 patients were enrolled in this randomized, double-blind study comparing losartan (50 to 100 mg once daily) with placebo, both taken in addition to conventional antihypertensive treatment (calcium-channel antagonists, diuretics, alpha-blockers, beta-blockers, and centrally acting agents), for a mean of 3.4 years. The primary outcome was the composite of a doubling of the base-line serum creatinine concentration, end-stage renal disease, or death. Secondary end points included a composite of morbidity and mortality from cardiovascular causes, proteinuria, and the rate of progression of renal disease., Results: A total of 327 patients in the losartan group reached the primary end point, as compared with 359 in the placebo group (risk reduction, 16 percent; P=0.02). Losartan reduced the incidence of a doubling of the serum creatinine concentration (risk reduction, 25 percent; P=0.006) and end-stage renal disease (risk reduction, 28 percent; P=0.002) but had no effect on the rate of death. The benefit exceeded that attributable to changes in blood pressure. The composite of morbidity and mortality from cardiovascular causes was similar in the two groups, although the rate of first hospitalization for heart failure was significantly lower with losartan (risk reduction, 32 percent; P=0.005). The level of proteinuria declined by 35 percent with losartan (P<0.001 for the comparison with placebo)., Conclusions: Losartan conferred significant renal benefits in patients with type 2 diabetes and nephropathy, and it was generally well tolerated.

Background: Microalbuminuria and hypertension are risk factors for diabetic nephropathy. Blockade of the renin-angiotensin system slows the progression to diabetic nephropathy in patients with type 1 diabetes, but similar data are lacking for hypertensive patients with type 2 diabetes. We evaluated the renoprotective effect of the angiotensin-II-receptor antagonist irbesartan in hypertensive patients with type 2 diabetes and microalbuminuria., Methods: A total of 590 hypertensive patients with type 2 diabetes and microalbuminuria were enrolled in this multinational, randomized, double-blind, placebo-controlled study of irbesartan, at a dose of either 150 mg daily or 300 mg daily, and were followed for two years. The primary outcome was the time to the onset of diabetic nephropathy, defined by persistent albuminuria in overnight specimens, with a urinary albumin excretion rate that was greater than 200 microg per minute and at least 30 percent higher than the base-line level., Results: The base-line characteristics in the three groups were similar. Ten of the 194 patients in the 300-mg group (5.2 percent) and 19 of the 195 patients in the 150-mg group (9.7 percent) reached the primary end point, as compared with 30 of the 201 patients in the placebo group (14.9 percent) (hazard ratios, 0.30 [95 percent confidence interval, 0.14 to 0.61; P< 0.001] and 0.61 [95 percent confidence interval, 0.34 to 1.08; P=0.081 for the two irbesartan groups, respectively). The average blood pressure during the course of the study was 144/83 mm Hg in the placebo group, 143/83 mm Hg in the 150-mg group, and 141/83 mm Hg in the 300-mg group (P=0.004 for the comparison of systolic blood pressure between the placebo group and the combined irbesartan groups). Serious adverse events were less frequent among the patients treated with irbesartan (P=0.02)., Conclusions: Irbesartan is renoprotective independently of its blood-pressure-lowering effect in patients with type 2 diabetes and microalbuminuria.

Background: Diabetic nephropathy is a chronic, progressive kidney disease with a mean rate of decline of in glomerular filtration rate (GFR) of 10 to 12 mL/min/year (natural history). The introduction of aggressive antihypertensive treatment has improved the renal prognosis during the last decades. To examine whether remission and regression of diabetic nephropathy are possible in type 1 diabetic patients, we analyzed data from a prospective observational cohort study that was started in 1983., Methods: We measured GFR with a 51Cr-EDTA plasma clearance technique every year for seven years (range 3 to 14 years) in 301 consecutive type 1 diabetic patients with diabetic nephropathy. Diabetic nephropathy was diagnosed clinically if the following criteria were fulfilled: persistent albuminuria> 200 microg/min, presence of diabetic retinopathy, and no evidence of other kidney or renal tract disease. Blood pressure, albuminuria, glycosylated hemoglobin A1c, and serum cholesterol were measured every three to four months during the study. In total, 271 patients received antihypertensive treatment, 179 patients predominantly with angiotensin-converting enzyme inhibitors. Remission was defined as albuminuria <200 microg/min sustained for at least one year and a decrease of at least 30% from preremission levels (surrogate endpoint), and regression as a rate of decline in GFR (DeltaGFR) equal to the natural aging process: < or =1 mL/min/year during the entire observation period (principal end point)., Results: The total number of patients who obtained remission was 92 (31%), with a duration of remission of [median (range)] 3.4 (1.0 to 14.1) years, and regression 67 (22%). The patients were stratified in quintiles by the average value of office mean arterial blood pressure (mean +/- SE): 93 +/- 0.5, 99 +/- 0.2, 103 +/- 0.1, 107 +/- 0.2, and 113 +/- 0.4 mm Hg. The prevalence of patients obtaining remission/regression was 58/42, 33/32, 25/11, 20/20, and 17/7% in each quintile, respectively. Spontaneous remission and regression occurred in 10 and 14 patients from the persistent normotensive group (N = 30), none of whom had ever received antihypertensive treatment. In all 301 consecutive patients, the (mean +/- SE) DeltaGFR was 4.0 +/- 0.2 mL/min/year during the investigation period., Conclusions: Our study suggests that aggressive antihypertensive treatment in type 1 diabetic patients can induce remission and regression in a sizable fraction of patients with diabetic nephropathy. Lower arterial blood pressure, reduced albuminuria, and better glycemic control were predictors of regression of diabetic nephropathy.

Unlabelled: The ability of the kidney to maintain constancy of glomerular filtration rate (GFR) over a wide range of renal perfusion pressures is termed autoregulation. Defective autoregulation of GFR has been demonstrated in patients with diabetic and non-diabetic nephropathy and in streptozotocin diabetic rats during hyperglycaemia. Information on the potential impact of acute changes in glycaemic control on autoregulation of GFR in diabetic patients is lacking. Therefore the aim of our study was to evaluate the effect of acute lowering of blood pressure (BP) on GFR during normoglycaemia and hyperglycaemia. We investigated 14 (12m/2f) normoalbuminuric patients with non-insulin dependent diabetes (NIDDM). The patients were examined in random order on two separate days with blood glucose (BG)<10 mmol/L or with BG>15 mmol/L. GFR (single shot [51Cr] EDTA plasma clearance technique) was measured twice each day; first without clonidine (baseline) followed by intravenous injection of clonidine 100-150 microg. We measured BG (One Touch 2), and BP (Takeda TM2420) several times during each GFR measurement. Clonidine reduced mean arterial blood pressure with 20 (1.4) vs. 16 (1.2) mmHg (mean (SE)) with BG<10mmol/L and with BG>15 mmol/L, respectively (p=0.053). GFR diminished in average from 92 (3.1) to 86 (3.7) ml/min/1.73m2 with BG<10 mmol/L (p<0.05), and from 102 (4.1) to 98 (4.2) ml/min/1.73 m2 with BG> 15 mmol/L, NS. Mean difference between changes in GFR (95% confidence interval) between the examination with BG<10 mmol/L and with BG>15 mmol/L were 2.3 (-1.3 to 5.9) ml/min/1.73 m2 (NS). The mean BG during normoglycaemia was 6.9 (0.3) vs.16.9 (0.4) during hyperglycaemia., Conclusion: Our study suggests that acute changes in glycaemic control have no detectable effect on autoregulation of GFR in NIDDM patients. Hyperglycaemia enhances GFR.

Objective: To compare the long-term effect on kidney function of a long-acting calcium antagonist (nisoldipine) versus a long-acting ACE inhibitor (lisinopril) in hypertensive type 1 diabetic patients with diabetic nephropathy., Research Design and Methods: We performed a 4-year prospective, randomized, double-dummy controlled study comparing nisoldipine (20-40 mg once a day) with lisinopril (10-20 mg once a day). The study was double-blinded for the first year and single-blinded thereafter. The study included 51 hypertensive type 1 diabetic patients with diabetic nephropathy. Three patients dropped out during the first month; results for the remaining 48 patients are presented., Results: At baseline, the two groups were comparable: glomerular filtration rate (GFR) was 85 +/- 5 and 85 +/- 6 ml x min(-1) x [1.73 m](-2); mean 24-h ambulatory blood pressure was 108 +/- 3 and 105 +/- 2 mmHg, and albuminuria was 1,554 mg/24 h (95% CI 980-2,465) and 1,033 mg/24 h (760-1,406) in the lisinopril and nisoldipine groups, respectively. Mean 24-h arterial blood pressure during the study did not differ between the lisinopril and nisoldipine groups (100 +/- 2 and 103 +/- 1 mmHg, respectively). The time-course of albuminuria differed between groups (P < 0.001). Whereas initiation of treatment with lisinopril resulted in a reduction from baseline albuminuria by 52% (95% CI 14-73), albuminuria in the nisoldipine group did not change throughout the study GFR declined in a biphasic manner with an initial (0-6 months) reduction of 1.3 +/- 0.3 ml x min(-1) x month(-1) in the lisinopril group compared with 0.2 +/- 0.4 ml x min(-1) x month(-1) in the nisoldipine group (P < 0.01). The subsequent sustained decline (6 to 48 months or the end of treatment) was identical in the two groups: 0.5 +/- 0.1 ml min(-1) x month(-1) (NS). Two patients in the lisinopril group and three patients in the nisoldipine group entered therapy for end-stage renal failure., Conclusions: Long-term treatment with lisinopril or nisoldipine has similar beneficial effects on progression of diabetic nephropathy in hypertensive type 1 diabetic patients.

Recent trials have linked calcium antagonists with adverse cardiovascular events in hypertensive patients with diabetes. A closer examination of these trials (in particular the Appropriate Blood Pressure Control in Diabetes [ABCD] trial and the Fosinopril Versus Amlodipine Cardiovascular Events Trial [FACET]) reveals a lack of data from which to draw conclusions of harm. In fact, based on the results of these trials and the recent Hypertension Optimal Treatment (HOT) Trial, one may conclude that the combination of a calcium antagonist with an ACE inhibitor is a rational therapeutic choice in patients with coexisting hypertension and diabetes.

Objective: To evaluate the effect of the ACE inhibitor ramipril as compared with placebo on left ventricular mass index (LVMI) in normotensive, nonalbuminuric NIDDM patients with left ventricular hypertrophy (LVH). Patients with NIDDM are characterized by excessive cardiovascular morbidity and mortality, and LVH, an independent risk factor for cardiac events, is often present in NIDDM patients., Research Design and Methods: A total of 38 normotensive, nonalbuminuric (albuminuria < 100 mg/24 h) NIDDM patients with LVH (LVMI > 131 g/m2 in men and > 100 g/m2 in women) were enrolled in a 6-month randomized, double-blind parallel group study to compare the effects of ramipril (5 mg/day) with placebo on LVMI (echocardiography, Vingmed CFM725, Diasonics Sonotron), QTc dispersion determined as the interlead variation in QTc interval on standard electrocardiogram (ECG), and 24-h ambulatory blood pressure (A&D TM2420, Tokyo, Japan). A total of 16 ramipril (10 men, 60 +/- 9 years [mean +/- SD]) and 15 placebo-treated (8 men, 55 +/- 10 years) patients completed the study, and their data are presented., Results: Ambulatory blood pressure was almost identical at baseline (132/76 +/- 3/1 vs. 133/74 +/- 5/2 mmHg [mean +/- SEM]) and remained stable during follow-up (134/76 +/- 3/1 vs. 136/74 +/- 6/2 mmHg) in the ramipril and placebo group, respectively. LVMI was comparable at baseline (137.1 +/- 7.0 vs. 129.6 +/- 3.7 g/m2) in the ramipril and placebo group, respectively, and decreased significantly more in the ramipril group as compared with the placebo group (17.6 +/- 3.0 vs. 5.7 +/- 4.6 g/m2, respectively, 11.9 [0.7-23.1] g/m2, mean difference [95% CI]; P = 0.037). QTc dispersion was comparable at baseline (60.2 [5.5] vs. 64.1 [6.5] ms) and did not change significantly during follow-up: -2.5 [7.0] vs. -12.2 [9.5] ms; mean difference 9.8 (-14.2 to 33.8 ms) in the ramipril and placebo group, respectively., Conclusions: Ramipril induces regression of LVH in normotensive, nonalbuminuric NIDDM patients, independent of reduction in systemic blood pressure.

The prevalence of abnormally elevated albumin excretion rate (> 30 mg/24 h) is approximately 40% in insulin-dependent (IDDM) and non-insulin-dependent (NIDDM) diabetic patients. Diabetes has become the leading cause of end-stage renal failure in the US, Japan and Europe. Approximately 90% of the direct and indirect cost of caring for diabetic patients are spent on the complications of diabetes. Identification of patients at high risk of developing diabetic nephropathy is possible by screening for microalbuminuria (30-300 mg/24 h). Elevated urinary albumin excretion rate indicates a substantially increased mortality risk in diabetic patients. Randomised controlled trials in normotensive IDDM and NIDDM patients with persistent microalbuminuria indicate that ACE inhibitors diminish urinary albumin excretion rate, postpone it and may even prevent progression to clinical overt nephropathy. These findings indicate that screening and intervention programs are likely to have life saving effects and lead to considerable economic savings. Systemic blood pressure elevation to a hypertensive level is an early and frequent phenomenon in diabetic nephropathy. Furthermore, nocturnal blood pressure elevation (non-dippers) occurs more frequently in patients with nephropathy. Systemic blood pressure elevation and to a lesser degree albuminuria accelerate the progression of diabetic nephropathy. Effective blood pressure reduction with non-ACE-inhibitors and/or ACE-inhibitors frequently in combination with diuretics: (a) reduces albuminuria; (b) delays the progression of nephropathy; (c) postpones renal insufficiency; and (d) improves survival in IDDM and NIDDM patients with diabetic nephropathy. A specific renal protective effect of ACE-inhibitors in diabetic nephropathy has been demonstrated in IDDM patients with moderately reduced kidney function (s-creatinine > 133 mumol/l) while the data conflict with NIDDM patients. Antihypertensive treatment for diabetic nephropathy simultaneously extends life and saves money. Finally, reduced risk of fatal and non-fatal cardiovascular events have been demonstrated when diabetic patients with isolated systolic hypertension are treated with blood pressure lowering agents. Absolute risk reduction with active treatment compared to placebo was twice as great for the diabetic versus non-diabetic patients (101/1000 versus 51/1000 randomised participants at the 5-year follow-up), reflecting the higher risk of diabetic patients. In conclusion, early detection and aggressive treatment of arterial hypertension with ACE-inhibitors, long acting calcium antagonist and low dose diuretics as first line drugs are highly warranted in diabetic patients with or without diabetic renal disease.

Prevalence: The prevalence of abnormally elevated urinary albumin excretion rate (> 30 mg/24 h) is approximately 40% in insulin-dependent and in non-insulin-dependent diabetic patients. Diabetes has become the leading cause of end-stage renal failure in Europe, USA and Japan. Approximately 90% of the direct and indirect costs of caring for diabetic patients are spent on the complications of diabetes., Risk Factors: Identification of patients at high risk of developing diabetic nephropathy is possible by screening for microalbuminuria (30-300 mg/24 h). Additional risk factors/ markers for development of nephropathy are male sex, genetic predisposition, ethnic conditions, early onset of diabetes, poor metabolic control, hyperfiltration, elevated prorenin and smoking. Elevated urinary albumin excretion rate indicates a substantially increased cardiovascular morbidity and mortality risk in diabetic patients., Prevention of Nephropathy: Randomized controlled trials in normotensive insulin-dependent and in non-insulin-dependent diabetic patients with persistent microalbuminuria indicate that angiotensin converting enzyme (ACE) inhibitors diminish urinary albumin excretion rate, and postpone and may even prevent progression to clinical overt nephropathy. These findings indicate that screening and intervention programs could probably save lives and lead to considerable economic savings., Treatment of Nephropathy: Systemic blood pressure elevation to a hypertensive level is an early and frequent phenomenon in diabetic nephropathy. Furthermore, nocturnal blood pressure elevation (non-dippers) occurs more frequently in patients with nephropathy. Systemic blood pressure elevation, hyperglycaemia, albuminuria and the D polymorphism in the ACE gene accelerate the progression of diabetic nephropathy. Studies of the impact of other potential progression promoters (i.e. smoking, hyperlipidaemia and protein intake) have yielded conflicting results. Effective blood pressure reduction using ACE inhibitors or drugs of other classes, or both, frequently in combination with diuretics reduces albuminuria, delays the progression of nephropathy, postpones renal failure and improves survival in patients with diabetic nephropathy. Antihypertensive treatment for diabetic nephropathy extends life and saves money.

Initiation of antihypertensive treatment in hypertensive non-insulin-dependent diabetic (NIDDM) patients with diabetic nephropathy induces a faster initial (0 to 6 months) and slower subsequent (6 months-end) decline in GFR [delta GFR (ml.min-1.1.73 m-2.month-1) approximately 1.5 vs. 0.4]. Whether this initial phenomenon is reversible (hemodynamic) or irreversible (structural damage) after prolonged antihypertensive treatment is not known. To elucidate these mechanisms we investigated 40 hypertensive NIDDM patients (age 61 +/- 7 years, mean +/- SD), known duration of diabetes 14 years (2 to 33 years) [median (range)] with diabetic nephropathy receiving antihypertensive treatment (angiotensin converting enzyme inhibition, N = 30) for 5 years (1 to 20 years). The following variables were measured the last day on antihypertensive treatment and one month after withdrawal of treatment; GFR (51Cr-EDTA), 24-hour arterial blood pressure (24 hr MABP, Takeda TM2420) and albuminuria (ELISA); the mean 24-hour MABP rose from 102 +/- 11 to 111 +/- 10 (P < 0.0001) and albuminuria [geometric mean (antilog SEM)] increased from 634 (1.3) to 1159 (1.2) (P < 0.0001), while GFR (mean +/- SD) remained unchanged (69 +/- 25 to 70 +/- 26 ml.min-1.1.73 m-2, P = 0.21), after withdrawal of antihypertensive treatment. A significant correlation between the relative change in the 24 hour MABP measurement and the relative change in GFR (r = 0.44, P < 0.01) was found. In conclusion, our results suggest that the faster initial decline in GFR after initiating antihypertensive treatment in hypertensive NIDDM patients with diabetic nephropathy is due to a irreversible effect, and should be accounted for when evaluating the beneficial effect of antihypertensive treatment on the progression of diabetic nephropathy in these patients.

Endothelial dysfunction is a prevalent phenomenon in non-insulin dependent diabetic (NIDDM) patients with hypertension and albuminuria, and may contribute to the development and progression of cardiovascular disease, which is the main cause of the high morbidity and mortality observed in these patients. Therefore the aim of our study was to evaluate whether inhibition of angiotensin-converting enzyme (with lisinopril 10-20 mg day-1) could ameliorate endothelial dysfunction more than reducing blood pressure with conventional antihypertensive treatment (atenolol 50-100 mg day-1), usually in combination with a diuretic. We performed a 12-month prospective, randomized, double-blind, parallel study in 43 hypertensive NIDDM patients with diabetic nephropathy (21 treated with lisinopril and 22 with atenolol). The following variables were measured: 24-h ambulatory blood pressure (ABP); transcapillary escape rate of albumin (TERalb; i.e. initial disappearance of intravenously injected 125I-labelled human serum albumin); serum concentrations of von Willebrand factor (vWF), using ELISA, and urinary albumin excretion rate (UAE). Data are presented for 32 patients (16 lisinopril and 16 atenolol; age 60 years, SD 8; 25 males) out of 35 who completed the study and had valid measurements of TERalb. At baseline the two groups were comparable; TERalb (8.5 (SEM 0.6) vs. 7.2 (0.4)%); vWF (2.09 (range 0.82-4.34) vs. 1.97 (0.95-3.86) IU ml-1; UAE 916 (x/divided by antilog SEM 1.3) vs. 1444 (1.2), and mean ABP 110 (SEM 3) vs. 113 (2) mmHg, in the lisinopril and atenolol group, respectively. During follow up, the mean ABP was equally reduced in the lisinopril and atenolol group, by 12 (SEM 2) vs. 10 (2) mmHg, respectively, TERalb decreased in the lisinopril group by 0.6 (SEM 0.7)%, whereas it increased in the atenolol group 1.5 (0.5)%; the mean difference was 2.2% (95% CI, 0.5 to 3.9; p = 0.015). UAE was reduced by 45% (95% CI, 25 to 60) in the lisinopril group vs. 10% (-15 to 30) in the atenolol group (p = 0.014). Serum vWF was not changed during follow up in either group. Our study suggests that lisinopril has both reno- and vasculoprotective properties in hypertensive NIDDM patients with diabetic nephropathy.

The aim of our study was to evaluate whether inhibition of ACE (lisinopril 10-20 mg/day) can reduce the rate of decline in kidney function more than reducing blood pressure with conventional antihypertensive treatment (atenolol 50-100 mg/day), usually in combination with a diuretic. We performed a prospective, randomized, parallel study for 42 months, double blind for the first 12 months and single blind thereafter. Forty-three (21 lisinopril and 22 atenolol) hypertensive NIDDM patients with diabetic nephropathy were enrolled. Data from 36 patients (17 lisinopril and 19 atenolol, 60 +/- 7 years of age, 27 men) who completed at least 12 months of the study period are presented. At baseline, the two groups were comparable: glomerular filtration rate (51Cr-EDTA plasma clearance) was 75 +/- 6 and 74 +/- 8 ml x min(-1) x 1.73 m(-2), mean 24-h ambulatory blood pressure (A&D TM2420) was 110 +/- 3 and 114 +/- 2 mmHg, and 24-h urinary albumin excretion rate was 961 (range 331-5,727) and 1,578 (476-5,806) mg/24 h in the lisinopril and atenolol groups, respectively. The mean follow-up time was similar, 37 and 35 months in the lisinopril and atenolol groups, respectively. Mean ambulatory blood pressure was equally reduced in the two groups, 12 +/- 2 and 10 +/- 2 mmHg in the lisinopril and atenolol groups, respectively. Glomerular filtration rate declined in a biphasic manner with a faster initial (0 to 6 months) change of 1.25 +/- 0.49 and 0.81 +/- 0.29 ml x min(-1) x month(-1) followed by a slower sustained decline (6 to 42 months) of 0.59 +/- 0.10 and 0.54 +/- 0.13 ml x min(-1) x month(-1) in the lisinopril and atenolol groups, respectively. No significant differences were observed in either initial or sustained decline in glomerular filtration rate between the two groups. Urinary albumin excretion was reduced (% reduction of baseline) more in the lisinopril than in the atenolol group, at 55 (95% CI 29-72) and 15% (-13 to 34), respectively (P = 0.01). In conclusion, the relentless decline in kidney function characteristically found in hypertensive NIDDM patients with diabetic nephropathy can be reduced equally effectively by two antihypertensive treatments, the beta-blocker atenolol and the ACE inhibitor lisinopril.

Our objective was to compare the effect of a long-acting calcium antagonist (nisoldipine) versus an ACE inhibitor (lisinopril) on albuminuria, arterial blood pressure, and glomerular filtration rate (GFR) in hypertensive IDDM patients with diabetic nephropathy. We performed a 1-year, double-blind, double-dummy, randomized, controlled study comparing nisoldipine (20-40 mg once daily) with lisinopril (10-20 mg once daily) in 52 hypertensive IDDM subjects with diabetic nephropathy. Three patients dropped out, and results for the remaining 49 (25 nisoldipine, 24 lisinopril) are presented. Diuretics were required in 10 nisoldipine- and 8 lisinopril-treated patients. Every 3 months, 24-h ambulatory blood pressure (TM2420, A&D, Tokyo, Japan) and albuminuria in three 24-h samples (enzyme immunoassay) were measured; GFR (51Cr-EDTA plasma clearance) was recorded every 6 months. Mean arterial blood pressure (24 h) was reduced from (mean +/- SE) 108 +/- 3 mmHg at baseline to 101 +/- 2 in average during treatment in the lisinopril group and from 105 +/- 2 to 103 +/- 2 in the nisoldipine group (P = 0.06 comparing changes in the two groups). Albuminuria was reduced 47% (95% CI 21-65) in the lisinopril group versus an increase of 11% (-3 to 27) in the nisoldipine group (P = 0.001). Fractional albumin clearance was reduced 37% (95% CI 4-59%) in the lisinopril versus an increase of 35% (8-69%) in the nisoldipine group (P < 0.01). GFR decreased from 85 +/- 5 ml x min(-1) x 1.73 m(-2) to 73 +/- 5 in the lisinopril group and from 84 +/- 6 to 80 +/- 7 in the nisoldipine group (P < 0.05). The effect of study medication on albuminuria and GFR was independent of changes in systemic blood pressure and baseline variables in multiple regression analyses. In summary, lisinopril reduced albuminuria, but also GFR, to a greater extent than did nisoldipine in hypertensive IDDM patients with diabetic nephropathy during the 1st year of treatment. Longer follow-up is required to clarify whether these drugs have different renoprotective effects.

We assessed the prognosis of diabetic nephropathy during long-term antihypertensive treatment as compared to the prognosis during the natural history of this complication in a prospective study of all IDDM patients (N = 45) aged under 50 with onset of diabetes before the age of 31 who developed diabetic nephropathy between 1974 and 1978 at Steno Diabetes Center, and were followed until death or for at least 16 years [median 16 (4 to 21) years]. Antihypertensive treatment was started 3 (0 to 13) years after onset of diabetic nephropathy. Mean arterial blood pressure at start of antihypertensive treatment was 148/96 (sd 12/10) mm Hg and 143/86 (16/6) mm Hg during the whole interval of antihypertensive treatment (P < 0.01). The cumulative death rate was 45% (95% C.I. 38 to 52) 16 years after onset of diabetic nephropathy, in contrast to previous reports 88% and 94% 12 and 16 years after onset of diabetic nephropathy, respectively. The median survival time in our study exceeded 16 years as compared to five and seven years in untreated patients in the past. Uremia was the main cause of death (12 patients; 55%). In 1994 serum creatinine was 116 (74 to 311) mumol/liter in the 23 surviving patients. The preservation of kidney function and the prognosis of diabetic nephropathy has improved during the past two decades mainly because of effective antihypertensive treatment.

Initiation of antihypertensive treatment (AHT) in hypertensive insulin-dependent diabetic (IDDM) patients with diabetic nephropathy (DN) induces a faster initial (0 to 6 months) and a slower subsequent (6 months to end of observation) decline in GFR [delta GFR (ml/min/month) approximately 1.5 vs. 0.35]. Whether this initial phenomenon is reversible (hemodynamic) or irreversible (structural damage) after prolonged AHT is not known. To elucidate these mechanisms we investigated 42 hypertensive IDDM patients (16F/26M, age 40 +/- 7 years, mean +/- SD) with DN receiving AHT (angiotensin converting enzyme inhibition, N = 30) for 6 (2 to 15) years [median (range)]. GFR (ml/min/1.73 m2), arterial blood pressure (BP, mm Hg) and albuminuria (mg/24 hr) were measured the last day on AHT and one month after withdrawal of AHT. The measured variables were all significantly elevated after withdrawal of AHT: GFR [mean(SEM)] from 76(4) to 81(4) (P < 0.0001), BP [mean(SEM)] from 140/82 (2/1) to 151/89 (2/1) (P < 0.0005) and albuminuria [geometric mean (antilog SEM)] from 704 (1.2) to 1122 (1.2) (P < 0.0001). A correlation between relative rise in systolic blood pressure (delta Sys%) and relative change in GFR (delta GFR%) was found (r = 0.44, P < 0.005). Our results render some support of the hypothesis that the faster initial decline in GFR is due to a functional (hemodynamic) effect of AHT, which does not attenuate over time, while the subsequent slower decline reflects the beneficial effect on progression of diabetic nephropathy.

Diabetic nephropathy is a clinical syndrome characterized by persistent albuminuria (> 300 mg/24 h), a relentless decline in glomerular filtration rate, and elevated systemic blood pressure. The prevalence of an abnormally elevated albumin excretion rate (> 30 mg/24 h) is approximately 40% in patients with both insulin-dependent diabetes mellitus (IDDM) and non-insulin-dependent diabetes mellitus (NIDDM). Diabetes has become the leading cause of end-stage renal failure in the United States and Japan and it is still the second leading cause in Europe. Identification of patients at high risk of developing diabetic nephropathy is possible by screening for microalbuminuria (30 to 300 mg/24 h). Randomized controlled trials in normotensive IDDM and NIDDM patients with persistent microalbuminuria indicate that angiotensin-converting enzyme (ACE) inhibitors diminish urinary albumin excretion rate and postpone or may even prevent progression to clinically overt diabetic nephropathy. These findings suggest that screening and intervention programs are likely to have life-saving effects and lead to considerable economic savings. High blood pressure is an early and frequent phenomenon that can accelerate the course of diabetic nephropathy. Besides ACE inhibitors, conventional antihypertensive treatment (mainly beta-blockers and diuretics) reportedly reduce albuminuria and diminish the loss of kidney function in IDDM patients with diabetic nephropathy. The same beneficial effect has been demonstrated using ACE inhibition combined with diuretics in hypertensive IDDM patients with overt nephropathy.(ABSTRACT TRUNCATED AT 250 WORDS)

Diabetic nephropathy is the main cause of increased mortality and morbidity in IDDM patients. The effect of antihypertensive treatment on the progression of the nephropathy is highly variable. The aim of this study was to evaluate putative predictors of the progression in diabetic nephropathy during long-term antihypertensive treatment. Eighteen hypertensive IDDM patients with diabetic nephropathy, who had not been treated previously, were followed during 3 years of treatment with captopril and frusemide or bendrofluazide. Glomerular filtration rate, arterial blood pressure, albuminuria and adjusted albuminuria were used as putative predictors of rate of decline in glomerular filtration. Fall rate in glomerular filtration rate was 4.6 (4.0) ml.min-1.year-1 (mean (SD)) during treatment. Relative change in albuminuria (ratio of first year of treatment/baseline) and albuminuria during first year of treatment were significantly correlated to fall rate in glomerular filtration rate during 3 years of treatment (r = 0.73, p < 0.001) and (r = 0.60, p < 0.01), respectively. Arterial blood pressure and glomerular filtration rate measured at baseline, during first year of treatment or relative changes in these variables did not correlate with fall rate in glomerular filtration rate during 3 years of treatment. Haemoglobin A1c, serum-cholesterol, protein intake and sodium excretion remained unchanged during treatment, and were not correlated with loss of kidney function. Reduction in albuminuria during captopril treatment predicts an attenuated rate of decline in glomerular filtration rate in early diabetic nephropathy (glomerular filtration rate > 70 ml.min-1.1.73 m-2). The finding suggests a clinical application in monitoring the efficacy of antihypertensive treatment in early diabetic nephropathy.

The effect of long-term, aggressive, antihypertensive treatment on kidney function in diabetic nephropathy was studied prospectively in 11 insulin-dependent diabetic patients (mean age, 30 years). Renal function was assessed every 4 months by measurement of glomerular filtration rate (GFR) (single-bolus 51Cr-EDTA technique) and by albuminuria (radial immunodiffusion). During the median pretreatment period of 2.4 years (range, 1.9 to 5.5 years), the GFR decreased significantly and albuminuria and the arterial blood pressure increased significantly. During the 9.7-year (range, 2.8 to 10.4 year) period of antihypertensive treatment with metoprolol, hydralazine, and furosemide, the arterial blood pressure decreased from 143/96 mm Hg to 130/84 mm Hg and albuminuria decreased from 1,038 micrograms/min to 547 micrograms/min. The rate of decline in GFR decreased from 10.7 mL/min/yr (range, 5.3 to 17.5 mL/min/yr) before treatment to 2.5 mL/min/yr (range, 0.5 to 4.8 mL/min/yr) during treatment. The rate of decline in GFR is significantly smaller during the last 6 years compared with the first 3 years in patients who received long-term antihypertensive treatment (> or = 9 years). One patient died from acute myocardial infarction (GFR, 46 mL/min/1.73 m2). Effective antihypertensive treatment postpones renal insufficiency in diabetic nephropathy.

Diabetic nephropathy is the main cause of the increased morbidity and mortality in insulin-dependent diabetes mellitus (IDDM) patients. Elevated blood pressure accelerates and effective blood pressure reduction with beta-blockers and/or angiotensin-converting enzyme (ACE) inhibitors delays the progression of nephropathy and reduces albuminuria. All previous reports dealing with the natural history of diabetic nephropathy demonstrated a cumulative death rate between 50 and 77% 10 yr after onset of nephropathy. Effective antihypertensive treatment reduced the cumulative death rate to 15-20% 10 yr after onset of nephropathy. Recent randomized control studies indicate that ACE inhibition may delay and even prevent the development of diabetic nephropathy in normotensive IDDM patients with persistent microalbuminuria. Several cross-sectional and prospective studies suggest an association between elevated blood pressure and the development and progression of diabetic retinopathy. Furthermore, carotid insufficiency or other causes of unilaterally or bilaterally reduced retinal blood flow (pressure) diminish the development of diabetic retinopathy. Diabetic retinopathy is characterized by abnormal leakage of fluorescein through the blood-retinal barrier, an abnormality that can be reversed during antihypertensive treatment. It is well documented that elevated blood pressure, poor metabolic control, and diabetic microangiopathy independently enhance the endothelial leakage of plasma proteins in diabetes mellitus. A link between capillary hypertension, increased extravasation of plasma proteins, and the development and progression of diabetic microangiopathy has been suggested. Blood pressure reduction diminishes the extravasation of plasma proteins. The above results strongly support the case for early and effective treatment of arterial blood pressure elevation in diabetes.

The primary cause of arterial hypertension and of the increased morbidity and mortality in patients with insulin-dependent diabetes mellitus (IDDM) is diabetic nephropathy. About 35% of IDDM patients develop persistent albuminuria, an irreversible decline in the glomerular filtration rate and elevated blood pressure, which collectively contribute to the clinical syndrome of diabetic nephropathy. The excess mortality of IDDM patients with nephropathy is 80-100 times greater than that of an age- and sex-matched non-diabetic population. Diabetic nephropathy is the single most important cause of end-stage renal disease in the Western world, accounting for over a quarter of all such cases. Blood pressure elevation is a frequent finding, even in the early stages of diabetic nephropathy. Elevated blood pressure accelerates diabetic nephropathy, while an effective blood pressure reduction delays the progression of nephropathy and reduces albuminuria. A reduction in glomerular capillary hydraulic pressure may be the crucial factor. All previous reports dealing with the natural history of diabetic nephropathy have demonstrated a cumulative death rate of between 50% and 77% 10 years after the onset of nephropathy. Effective antihypertensive treatment has reduced this rate to 15-20%.

Our longitudinal study of urinary albumin excretion rate in long-term insulin-dependent diabetics without proteinuria (negative albustix) suggests that early detection of patients at high and low risk of developing persistent proteinuria, i.e., diabetic nephropathy, is possible by using a sensitive method for albumin determination. Our prospective studies in young insulin-dependent diabetics with diabetic nephropathy show that the rate of decline in glomerular filtration rate (GFR) varies considerably, with a mean of 0.75 ml/min/mo and a range from 0.1 to 1.50 ml/min/mo, and that an increase in arterial blood pressure to a hypertensive level is an early feature; 43% of the patients had diastolic blood pressure greater than 100 mm Hg. Early and aggressive antihypertensive treatment reduces both albuminuria and the rate of decline in GFR in young patients with diabetic nephropathy.

The effect of long term, aggressive antihypertensive treatment on kidney function in diabetic nephropathy was studied prospectively in 11 insulin dependent diabetics (mean age 30). During the mean pretreatment period of 32 (range 23-66) months the glomerular filtration rate decreased significantly and albuminuria and the arterial blood pressure increased significantly. During the 72 (range 32-91) month period of antihypertensive treatment the average arterial blood pressure fell from 143/96 mm Hg to 129/84 mm Hg and albuminuria decreased from 1038 micrograms/min to 504 micrograms/min. The rate of decline in the glomerular filtration rate decreased from 0.89 (range 0.44-1.46) ml/min/month before treatment to 0.22 (range 0.01-0.40) ml/min/month during treatment. The rate of decline in the glomerular filtration rate was significantly smaller during the second three years compared with the first three years in patients who received long term antihypertensive treatment (greater than or equal to 6 years). One patient died from acute myocardial infarction (glomerular filtration rate 46 ml/min/1.74 m2). Effective antihypertensive treatment postpones renal insufficiency in diabetic nephropathy.

The effect of early aggressive antihypertensive treatment on kidney function in diabetic nephropathy was studied prospectively in ten insulin-dependent diabetics (mean age 29 years). During the mean pretreatment period of 29 (range 23-38) months the glomerular filtration rate (GFR) decreased significantly and the urinary albumin excretion rate and arterial blood pressure rose significantly. During the 39 month (range 28-48) period of antihypertensive treatment with metoprolol, hydralazine, and frusemide (furosemide) or thiazide, arterial blood pressure fell from 144/97 mm Hg (mean of all pretreatment values) to 128/84 mm Hg (mean of all post-treatment values), urinary albumin excretion from 977 micrograms/min to 433 micrograms/min, and GFR from 80 to 62 ml/min/1 . 73 m2. The rate of decline in GFR decreased from 0.91 ml/min/month before treatment to 0.39 ml/min/month (range 0.08 to 0.68 ml/min/month) during treatment.

The effect of hypotensive therapy on the transcapillary escape rate of albumin (TERalb) was studied in eight hypertensive insulin-dependent diabetic patients (mean age 29, range 19-42 years) with nephropathy and retinopathy. Transcapillary escape rate of albumin (initial disappearance of intravenously injected 125I-labelled human serum albumin), urinary albumin excretion rate (radial immunodiffusion), and glomerular filtrate rate (single bolus 51-Cr-EDTA technique) were measured. After hypotensive treatment (mean duration, 23 months, range 7-39 months) with combinations of metoprolol, hydralazine, and frusemide or thiazide diuretics, arterial blood pressure fell from 152/103 +/- 18/6 mmHg (mean +/- SD) to 133/81 +/- 12/10 mmHg (p less than 0.01), transcapillary escape rate of albumin from 10.2 +/- 1.8 to 8.1 +/- 1.8% of intravascular mass of albumin/h (p less than 0.01), albuminuria from 1803 (370-5066) micrograms/min to 940 (101-2676) micrograms/min (median and range, p less than 0.05), and glomerular filtration rate from 103 +/- 23 to 84 +/- 22 ml/min/1.73 m2 (p less than 0.01). Our study suggests that effective hypotensive treatment reduces the abnormally elevated albumin leakage characteristically found in insulin-dependent diabetic patients with clinical microangiopathy. This may be due to a reduction in the hydrostatic pressure in the microcirculation.

Urinary albumin excretion rate (radial immunodiffusion), glomerular filtration rate (GFR) (single-shot 51Cr-EDTA technique), and arterial blood pressure (BP) were measured in 12 juvenile-onset, insulin-dependent diabetic patients with persistent proteinuria (greater than 0.5 g/day) due to diabetic nephropathy. Mean age of the patients was 30 yr. All patients had a diastolic blood pressure greater than or equal to 95 mm Hg. Metoprolol, hydralazine, and furosemide or thiazide were used as antihypertensives. During the 12-mo treatment period, BP decreased from 151/104 to 133/85 mm Hg (P less than 0.001), the urinary albumin excretion rate diminished from 1447 to 613 micrograms/min (P less than 0.005), and GFR declined from 96 to 89 ml/in/1.73 m2 (P less than 0.01). A linear relationship between mean blood pressure and the logarithm of the albuminuria was found (r = 0.48, P less than 0.01). Arterial hypertension is an early feature of diabetic nephropathy in young insulin-dependent patients. Early and aggressive treatment of that condition decreases albuminuria, probably due to reduced intraglomerular filtration pressure. Whether sustained reduction in arterial blood pressure to near-normal levels during several years also reduces the rate of decline in GFR in diabetic nephropathy remains to be established.

Objective: To assess the effect of long term antihypertensive treatment on prognosis in diabetic nephropathy., Design: Prospective study of all insulin dependent diabetic patients aged under 50 with onset of diabetes before the age of 31 who developed diabetic nephropathy between 1974 and 1978 at Steno Memorial Hospital., Setting: Outpatient diabetic clinic in tertiary referral centre., Patients: Forty five patients (20 women) with a mean age of 30 (SD 7) years and a mean duration of diabetes of 18 (7) years at onset of persistent proteinuria were followed until death or for at least 10 years., Interventions: Antihypertensive treatment was started a median of three (0-13) years after onset of nephropathy. Four patients (9%) received no treatment, and 9 (20%), 13 (29%), and 19 (42%) were treated with one, two, or three drugs, respectively. The median follow up was 12 (4-15) years., Main Outcome Measures: Arterial blood pressure and death., Results: Mean blood pressure at start of antihypertensive treatment was 148/95 (15/50) mm Hg. Systolic blood pressure remained almost unchanged (slope -0.01 (95% confidence interval -0.39 to 0.37) mm Hg a year) while diastolic blood pressure decreased significantly (0.87 (0.65 to 1.10) mm Hg a year) during antihypertensive treatment. The cumulative death rate was 18% (8 to 32%) 10 years after onset of nephropathy, in contrast to previous reports of 50% to 77% 10 years after onset of nephropathy. As in previous studies, uraemia was the main cause of death (9 patients; 64%)., Conclusions: The prognosis of diabetic nephropathy has improved during the past decade largely because of effective antihypertensive treatment.

The purpose of our prospective study was to evaluate the long-term effect of aggressive antihypertensive treatment on glomerular filtration rate and albuminuria in young female and male patients with insulin-dependent diabetes mellitus with diabetic nephropathy and blood pressure greater than 90 mm Hg. Eight patients received treatment with metoprolol (200-400 mg/day), hydralazine (100-200 mg/day), and furosemide (80-500 mg/day). The untreated control group consisted of eight patients matched for age (mean 32 years), diabetes duration (mean 17 years), and sex (two female and six male patients). All patients except one had diabetic retinopathy. Glomerular filtration rate was measured after a single intravenous injection of 51Cr-labeled ethylenediaminetetraacetic acid. Urinary albumin concentration was determined with a radial immunodiffusion method. The investigations were performed two to four times per year in each patient. The mean observation period was 59 and 27 months in the treated and untreated groups respectively. Due to a considerable rise in arterial blood pressure, it was considered unethical to prolong the observation in the untreated group. Arterial blood pressure rose from 140/96 +/- 4/1 to 150/100 +/- 3/2 mm Hg; albuminuria increased from 1517 +/- 502 to 1911 +/- 120 micrograms/min; and glomerular filtration rate decreased by a mean of 0.84 +/- 0.17 ml/min/mo in the untreated group. Antihypertensive treatment induced blood pressure reduction 151/100 +/- 3/2 to 131/87 +/- 2/1 mm Hg; diminished albuminuria 1467 +/- 515 to 729 +/- 65 micrograms/min; and caused a slow rate of decline in GFR, mean 0.37 +/- 0.08 ml/min/mo.(ABSTRACT TRUNCATED AT 250 WORDS)

Background: The ability of the kidney to maintain constancy of the glomerular filtration rate (GFR) over a wide range of renal perfusion pressures is termed autoregulation. Defective autoregulation of GFR has been demonstrated in diabetic nephropathy. Whether this is also the case in patients with nondiabetic nephropathies is not known. Methods: We investigated the effect of acute lowering of blood pressure (BP) on GFR in 16 (8 males and 8 females) albuminuric subjects suffering from different nondiabetic nephropathies and in 14 (7 males and 7 females) controls matched with respect to sex, age, BP, and baseline GFR. The subjects received in random order an intravenous injection of either clonidine (150 to 225 microg) or saline (0.154 mmol/liter) within two weeks. We measured GFR ([51Cr]-EDTA), albuminuria (enzyme-linked immunosorbent assay; ELISA), and BP (Takeda TM-2420). Results: Clonidine induced similar reductions in mean arterial BP 17 (2) versus 19 (2) mm Hg [mean (SE)] in patients with nephropathy and in controls, respectively. GFR diminished in average from 89 (6) to 82 (5) ml/min/1.73 m2 (P < 0.05), and albuminuria declined from a geometric mean of 1218 (antilog SE 1.3) microg/min to 925 (1.3) in the patients with nondiabetic nephropathies (P < 0.05), whereas these variables remained unchanged in the control group. The mean difference between changes in GFR (95% confidence interval) between the nondiabetic macroalbuminuric and control subjects was 6.1 (-0.03 to 12.21) ml/min/1.73 m2 (P = 0.051). Conclusion: Our study suggests that albuminuric patients with nondiabetic nephropathies frequently suffer from impaired autoregulation of GFR. [ABSTRACT FROM AUTHOR]