Renal protection and antihypertensive drugs: current status

New Insights into the Nephroprotective Potential of Lercanidipine

Kidneys are responsible for many crucial biological processes in the human body, including maintaining the water-electrolyte balance, pH, and blood pressure (BP), along with the elimination of toxins. Despite this, chronic kidney disease (CKD), which affects more and more people, is a disease that develops insidiously without causing any symptoms at first. The main purpose of this article is to summarize the existing literature on lercanidipine, with a particular focus on its nephroprotective properties. Lercanidipine is a third-generation dihydropyridine (DHP) blocker of calcium channels, and as such it possesses unique qualities such as high lipophilicity and high vascular selectivity. Furthermore, it acts by reversibly inhibiting L-type and T-type calcium channels responsible for exerting positive renal effects. It has been shown to reduce tissue inflammation and tubulointerstitial fibrosis, contributing to a decrease in proteinuria. Moreover, it exhibited antioxidative effects and increased expression of molecules responsible for repairing damaged tissues. It also decreased cell proliferation, preventing thickening of the vascular lumen. This article summarizes studies simultaneously comparing the effect of lercanidipine with other antihypertensive drugs. There is still a lack of studies on the medications used in patients with CKD, and an even greater lack of studies on those used in patients with concomitant hypertension. Therefore, further studies on lercanidipine and its potential in hypertensive patients with coexisting CKD are required.

Incidence and Risk Factors of Hypertension Following Partial Nephrectomy in Patients With Renal Tumors: A Cross-sectional Study of Postoperative Home Blood Pressure and Antihypertensive Medications

INTRODUCTION

We aimed to evaluate the incidence and risk factors for nephrectomy-related hypertension (NR-HT) in patients with renal tumors who underwent partial nephrectomy (PN) or radical nephrectomy (RN).

PATIENTS AND METHODS

A retrospective cross-sectional follow-up survey of postoperative home blood pressure (BP) and defined daily dose (DDD) of antihypertensive medications was conducted in patients with renal tumors who underwent PN (210 patients) or RN (120 patients), and they were compared. We evaluated the incidence and risk factors for NR-HT, defined as the addition of antihypertensive medications in doses of 1 DDD or more after surgery, or postoperative BP of 140/90 mmHg with an increase of 20 mmHg from preoperative BP with no reduction in dose of antihypertensive medications.

RESULTS

Both systolic (mean, 124 vs. 129 mmHg; P < .001) and diastolic BP (mean, 74 vs. 79 mmHg; P < .001) significantly increased after PN compared with RN. Systolic (P < .001) and diastolic (P = .003) BP increased significantly more after PN than after RN, and NR-HT was more frequent after PN than after RN (16% vs. 5%; P = .002). PN (odds ratio [OR], 2.93; P = .022) and higher postoperative peak C-reactive protein (OR, 2.34; P = .017) were independently associated with NR-HT. When limited to only the patients who underwent PN, acute kidney injury (OR, 2.65; P = .036) and higher postoperative peak C-reactive protein (OR, 2.54; P = .016) were independent risk factors for NR-HT.

CONCLUSION

PN may cause postoperative progression of hypertension possibly through renal parenchymal damage.

Early RAAS Blockade Exerts Renoprotective Effects in Autosomal Recessive Alport Syndrome

Alport syndrome is a progressive renal disease caused by mutations in COL4A3, COL4A4, and COL4A5 genes that encode collagen type IV alpha 3, alpha 4, and alpha 5 chains, respectively. Because of abnormal collagen chain, glomerular basement membrane becomes fragile and most of the patients progress to end-stage renal disease in early adulthood. COL4A5 mutation causes X-linked form of Alport syndrome, and two mutations in either COL4A3 or COL4A4 causes an autosomal recessive Alport syndrome. Recently, renin-angiotensin-aldosterone system (RAAS) blockade has been shown to attenuate effectively disease progression in Alport syndrome. Here we present three Japanese siblings and their father all diagnosed with autosomal recessive Alport syndrome and with different clinical courses, suggesting the importance of the early initiation of RAAS blockade. The father was diagnosed with Alport syndrome. His consanguineous parents and his wife were healthy. All three siblings showed hematuria since infancy. Genetic analysis revealed that they shared the same gene mutations in COL4A3 in a compound heterozygous state: c.2330G>A (p.Gly777Ala) from the mother and c.4354A>T (p.Ser1452Cys) from the father. Although RAAS blockade was initiated for the older sister and brother when their renal function was already impaired, it did not attenuate disease progression. In the youngest brother, RAAS blockade was initiated during normal renal function stage. After the initiation, his renal function has been normal with the very mild proteinuria to date at the age of 17 years. We propose that in Alport syndrome, RAAS blockade should be initiated earlier than renal function is impaired.

In vivo visualization of the antialbuminuric effects of the angiotensin-converting enzyme inhibitor enalapril

Angiotensin-converting enzyme (ACE) inhibitors are commonly used antiproteinuric drugs. Here we assessed the effect of the ACE inhibitor enalapril on the glomerular sieving coefficient of albumin (GSCA) using intravital multiphoton microscopy. Munich Wistar Frömter (MWF) rats were used as a model of hypertension-related glomerular lesions. Young (9-week-old) MWF rats were nonproteinuric, similar to what was observed in control Wistar rats. However, urinary albumin excretion in the MWF rats gradually increased during aging, averaging 0.00062 ± 0.0001 at age 9 weeks and 0.0054 ± 0.0003 (mg/mOsmol per liter) at age 52 weeks (P < 0.0001). Albuminuria in aged MWF rats was accompanied by structural changes, which were indicative of glomerular lesions. The GSCA was low in young MWF rats but increased markedly during aging, averaging 0.00057 ± 4.7 × 10(-5) (n = 25) in young MWF rats and 0.0027 ± 0.00036 in 52-week-old MWF rats (n = 36; P < 0.0001). Treatment of proteinuric 12-month-old MWF rats with enalapril over a 4-week period reduced the GSCA from 0.0027 ± 0.00036 to 0.00139 ± 0.00013 (P = 0.0005). Similarly, urinary albumin excretion was reduced, averaging 0.0051 ± 0.0003 and 0.0036 ± 0.0005 mg/mOsmol per liter before and after enalapril administration, respectively (P = 0.0089). In parallel, enalapril treatment reduced the mean arterial blood pressure (144.6 ± 6.5 mm Hg in untreated versus 110.9 ± 0.6 mm Hg in enalapril-treated MWF rats) and increased the glomerular filtration rate from 1.64 ± 0.3 ml/min to 3.58 ± 0.3 ml/min (P = 0.0025 versus baseline). In summary, enalapril reduced the GSCA in proteinuric MWF rats, which was paralleled by a similar reduction in urinary albumin excretion. These data suggest that glomerular rather than tubular mechanisms account for the beneficial antiproteinuric effects of the ACE inhibitor.

Role of manidipine in the management of patients with hypertension

Manidipine is a third-generation dihydropyridine calcium antagonist, which causes systemic vasodilation by inhibiting the voltage-dependent calcium inward currents in smooth muscle cells. In clinical studies, manidipine has been shown to significantly lower office and 24-h blood pressure compared with placebo in patients with essential hypertension. The resulting reduction in blood pressure is maintained over 24 h, with preservation of the circadian blood pressure pattern; its blood pressure-lowering capacity appears to be similar to that of other calcium antagonists. In elderly patients with mild-to-moderate essential hypertension, manidipine is able to significantly decrease blood pressure compared with placebo for up to 3 years of treatment. The drug also significantly lowers blood pressure in patients with hypertension and concomitant Type 2 diabetes mellitus or renal impairment, and is devoid of adverse metabolic effects. It is well-tolerated with few untoward adverse effects related to vasodilation. In particular, manidipine appears to have less potential for pedal edema than other calcium channel blockers.

Andrographolide and 14-deoxy-11,12-didehydroandrographolide from Andrographis paniculata attenuate high glucose-induced fibrosis and apoptosis in murine renal mesangeal cell lines

ETHNOPHARMACOLOGICAL RELEVANCE

Extracts of Andrographis paniculata Nees are used for various ethnomedical conditions including hyperglycemia and hypertension complications.

AIM OF THE STUDY

The purpose of this study is to evaluate the anti-diabetic nephropathy effect of diterpene lactones andrographolide (AP1) and 14-deoxy-11,12-didehydroandrographolide (AP2) from Andrographis paniculata.

MATERIALS AND METHODS

MES-13, a SV40-transformed murine glomerular mesangial cell line, was cultured in high concentration of glucose to induce diabetic nephropathy phenotypes, which include secretion of extracellular matrix protein fibronectin, cytokine TGF-β, states of oxidative stress, and apoptosis marker caspase-3.

RESULTS

Our data suggest that addition of compounds AP1 or AP2 reduces the phenotypes indicating diabetic nephropathy in MES-13 cells. The compound AP2 showed potent activity than AP1 in the reduction of apoptosis marker caspase-3, fibrosis marker TGF-β, and PAI-1. Furthermore, AP1 and AP2 do not have antioxidant ability in acellular environment; however, addition of AP1 and AP2 reduced intracellular oxidative states in high glucose cultured MES-13 cells.

CONCLUSION

This is the first report on anti-diabetic nephropathy effect of AP1 and AP2 in part due to the regulation of intracellular signaling transduction, not mere clearance of reactive oxygen species. Thus, this study may be useful for drug development or food supplement for diabetes and nephropathy from Andrographis paniculata.

Decreased incidence of lupus nephritis in northern Norway is linked to increased use of antihypertensive and anticoagulant therapy

BACKGROUND

Lupus nephritis (LN) remains a severe complication in systemic lupus erythematosus (SLE). Over the last decade, antiphospholipid antibodies have become a part of SLE classification criteria, and awareness of cardiovascular morbidity and its risk factors in SLE has increased. This study investigated the potential effect of these alterations on the presentation and severity of LN.

METHODS

This is an observational study of two subsequent SLE inception cohorts based on 1982 American College of Rheumatology (acr) classification criteria (82acr; n=87, enrolled 1978-95) and the updated version in 1997 (97acr: n=62, enrolled 1996-2006). Annual incidence rates (AIR), point prevalence, clinical and histological features, and outcome of LN (defined as proteinuria with urinary casts and/or haematuria) were compared between both cohorts.

RESULTS

Between 1978 and 2006, the AIR for LN decreased from 0.7 to 0.45/100 000, while LN prevalence rose from 7 to 14/100 000. The relative risk reduction in the 97acr for early- and late-onset LN (> 3 months after SLE diagnosis) was 39% and 42%, respectively. Patients developing LN in the 97acr cohort (97LN+; n=11) had similar demographics, more often low avidity anti-dsDNA antibodies (Ab) and/or anti-cardiolipin Ab at SLE diagnosis, lower proteinuria and diastolic blood pressure, and similar histological findings to those in the 83acr cohort (82LN +; n=28). Following LN diagnosis, more 97LN + patients received pulse corticosteroids (55% vs. 7%), anticoagulants (46% vs. 4%) and antihypertensive drugs (46% vs. 11%). Three 82LN+ patients (11%) developed end-stage renal disease versus none in 97LN + during a 10-year follow-up.

CONCLUSIONS

Early detection of low avidity anti-dsDNA and antiphospholipid antibodies, probably in combination with early use of protective cardiovascular measures from SLE diagnosis onwards may contribute to reduced incidence and improved renal survival in LN.

Efficacy and safety of aliskiren in Japanese hypertensive patients with renal dysfunction

This 12-week, multicenter, open-label study assessed the efficacy, pharmacokinetics and safety of a once-daily aliskiren in Japanese hypertensive patients with renal dysfunction. Patients (n=40, aged 20-80 years) with mean sitting diastolic blood pressure (msDBP) >or=95 and <110 mm Hg and serum creatinine between >or=1.3 and <3.0 mg per 100 ml in males or between >or=1.2 and <3.0 mg per 100 ml in females were eligible. Patients began therapy with a once-daily morning oral dose of 75 mg of aliskiren. In patients with inadequate blood pressure control (msDBP >or=90 or mean sitting systolic blood pressure [msSBP] >or=140 mm Hg) and without safety concerns (serum potassium >5.5 mEq l(-1) or an increase in serum creatinine >or=20%), the aliskiren dose was increased to 150 mg and then to 300 mg in sequential steps starting from Week 2. Efficacy was assessed as change in msSBP/msDBP from baseline to the Week 8 endpoint (with the last observation carried forward). The mean reduction from baseline to Week 8 endpoint was 13.9+/-16.6 and 11.6+/-9.7 mm Hg for msSBP and msDBP, respectively. At the Week 8 endpoint, 65% patients had achieved blood pressure response (msDBP <90 or a 10 mm Hg decrease or msSBP <140 or a 20 mm Hg decrease) and 30% had achieved blood pressure control (msSBP <140 mm Hg and msDBP <90 mm Hg). Aliskiren was well tolerated with no new safety concerns in Japanese hypertensive patients with renal dysfunction.

Antiproteinuric effects of antihypertensive agents in non-diabetic hypertensive population

Arterial hypertension and proteinuria are important factors associated with the progression of both diabetic and nondiabetic chronic kidney disease. The objective of the present study was to determine the influence of different antihypertensive drug groups on urinary albumin excretion (UAE) as related to blood pressure in non-diabetic population. Subjects (n=39) with chronic renal disease accompanied by mild to moderate hypertension and varying degrees of proteinuria were divided into 3 groups based on UAE values and placed on nonpharmacological and/or treatment with an antihypertensive drug regimen (consisting of one or more antihypertensive drugs [beta blocker, ACE inhibitor or calcium-channel blocker]) to achieve a target blood pressure ≤ 130/85 mmHg. Periodic UAE measurements were performed. A reduction was observed over time in most patients, however, it reached statistical significance only in the microalbuminuric group (P<0.01). Patients were further stratified into 5 groups depending on assigned therapy: 0, nonpharmacological treatment; 1-drug group 1; 12-drug groups 1 and 2; 13-drug groups 1 and 3; 123-all 3 drug groups (1-ACE inhibitors, 2-beta blockers, 3-calcium channel blockers). A statistically significant change in mean UAE values at the start and end of the study period in patients assigned to drug groups 12, 13, and 123 was achieved (P < 0.05). Also, there was a statistically significant difference in the average reduction of proteinuria under varying antihypertensive drug regimens (P < 0.05). In conclusion, in patients with hypertension, changes in UAE depend on initial UAE values and administered antihypertensive treatment. ACE inhibitors combined with calcium channel blockers resulted in a higher UAE reduction than other drug groups.

EFFECT OF NOS INHIBITION ON RETINAL ARTERIAL AND CAPILLARY CIRCULATION IN EARLY ARTERIAL HYPERTENSION

BACKGROUND

Arterial hypertension is involved in the pathogenesis of end organ damage by influencing the ability of the vascular endothelium to produce nitric oxide (NO). This study analyzes changes of retinal and systemic NO-dependent circulation parameters by inhibiting nitric oxide synthase (NOS) in both hypertensive and normotensive individuals.

METHODS

In a double-blind crossover trial, 19 hypertensive patients (H, age 28.2 +/- 0.9 years) and 19 normotensive controls (N, age 26.9 +/- 0.9 years) were randomized treated either with candesartan or placebo. Both retinal capillary flow (RCF) and mean blood flow velocity of the central retinal artery (VCRA) were registered before and after NOS inhibition with N-monomethyl-L-arginine (L-NMMA, 3 mg/kg). In a subpopulation mean arterial pressure (MAP), cardiac output (CO), and the total peripheral resistance (TPR) were determined simultaneously.

RESULTS

Changes from baseline: In normotensive and hypertensive subjects infusion of L-NMMA led to an increase of MAP (N, +13.3 +/- 1.8%, P < 0.01; H, +14.3 +/- 2.4%, P < 0.01) and TPR (N, +36.9 +/- 3.8%, P < 0.01; H, +45.0 +/- 4.5%, P < 0.01), and to a decrease of CO (N, -21.1 +/- 1.5%, P < 0.01; H, -24.6 +/- 2.3%, P < 0.01). The L-NMMA effect on VCRA and RCF differed between controls and hypertensives. VCRA changed by + 17.3 +/- 6.2% (P < 0.05) and RCF by -7.3 +/- 3.0% (P < 0.05) in controls. In hypertensive subjects corresponding results were + 9.5 +/- 5.2% (P = NS) and + 2.7 +/- 3.8% (P = NS), respectively. The decrease of RCF due to L-NMMA was reduced in hypertension as compared to controls (P < 0.05). The calculated cross-sectional area of CRA was reduced by -58.7% in controls and increased by + 31.1% in hypertensive subjects. There was no significant correlation between the flow in the systemic and retinal circulation.

CONCLUSION

Only normotensives L-NMMA induces an acceleration of VCRA due to a probable vasoconstriction of the central retinal artery and despite of a reduced RCF. Already in early hypertension the NOS-dependent vascular tone in retinal arteries and capillaries is impaired. The regulation of the retinal capillary flow appeared to be independent from systemic circulation.

Renal protection in hypertensive patients: selection of antihypertensive therapy

Hypertension is common in chronic renal disease and is a risk factor for the faster progression of renal damage, and reduction of blood pressure (BP) is an efficient way of preventing or slowing the progression of this damage. International guidelines recommend lowering BP to 140/90 mm Hg or less in patients with uncomplicated hypertension, and to 130/80 mm Hg or less for patients with diabetic or chronic renal disease. The attainment of these goals needs to be aggressively pursued with multidrug antihypertensive regimens, if needed. The pathogenesis of hypertensive renal damage involves mediators from various extracellular systems, including the renin-angiotensin system (RAS). Proteinuria, which occurs as a consequence of elevated intraglomerular pressure, is also directly nephrotoxic. As well as protecting the kidneys by reducing BP, antihypertensive drugs can also have direct effects on intrarenal mechanisms of damage, such as increased glomerular pressure and proteinuria. Antihypertensive drugs that have direct effects on intrarenal mechanisms may, therefore, have nephroprotective effects additional to those resulting from reductions in arterial BP. Whereas BP-lowering effects are common to all antihypertensive drugs, intrarenal effects differ between classes and between individual drugs within certain classes. Angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARB) have beneficial effects on proteinuria and declining renal function that appear to be mediated by factors additional to their effects on BP. These RAS inhibitors are recommended as a first-line antihypertensive approach in patients with chronic kidney disease. The addition of diuretics and calcium channel antagonists to RAS inhibitor therapy is also considered to be a rational strategy to reduce BP and preserve renal function. Calcium channel antagonists are a highly heterogeneous class of compounds, and it appears that some agents are more suitable for use in patients with chronic renal disease than others. Manidipine is a third-generation dihydropyridine (DHP) calcium channel antagonist that blocks both L and T-type calcium channels. Unlike older-generation DHPs, which preferentially act on L-type channels, manidipine has been shown to have beneficial effects on intrarenal haemodynamics, proteinuria and other measures of renal functional decline in the first clinical trials involving hypertensive patients with chronic renal failure. Preliminary results from a trial in diabetic patients who had uncontrolled hypertension and microalbuminuria despite optimal therapy with an ACE inhibitor or an ARB suggest that manidipine may be an excellent antihypertensive drug in combination with RAS inhibitor treatment in order to normalise BP and albumin excretion in patients with diabetes.

Transforming growth factor beta1 and additional renoprotective effect of combination ACE inhibitor and angiotensin II receptor blocker in hypertensive subjects with minor renal abnormalities: a 24-week randomized controlled trial

OBJECTIVE

To verify the benefit of renin-angiotensin system blockade in hypertension, the effects of 24 weeks' losartan and ramipril treatment, both alone and in combination, on urinary albumin excretion (UAE) and circulating transforming growth factor beta1 (TGF beta1) have been evaluated in hypertensive subjects with minor renal abnormalities.

DESIGN AND METHODS

Fifty-one patients with stage 1 and 2 essential hypertension and with UAE > or = 20 mg/24 h but with maintained renal function have been included. After a 4-week run-in with placebo administration, a randomized double-blind, three-arm double-dummy trial was used. All the hypertensives (HT) were allocated randomly to three treatment arms (17 patients for each group) and they were single-matched for age, gender, body mass index (BMI), systolic and diastolic blood pressure. Active treatment consisted of losartan (50 mg/day), ramipril (5 mg/day) and combined (losartan 50 mg/day plus ramipril 5 mg/day) for 24 weeks. Hydrochlorothiazide 12.5 mg/day was added in HT patients with uncontrolled blood pressure (> or = 140/90 mmHg) during the active treatment period. In all patients UAE, by immunonephelometric assay; circulating TGF beta1 by a solid-phase specific sandwich enzyme-linked immunosorbent assay (ELISA); and blood urea nitrogen (BUN), creatinine and creatinine clearance and potassium, by routine laboratory methods, were determined after placebo treatment and 24 weeks follow-up.

RESULTS

The three treatment groups were comparable for gender, age, BMI, blood pressure, UAE and renal function measurements. During the active treatment period it was necessary to add hydrochlorothiazide in five patients--two each of the losartan and ramipril groups and one of the combined group. At the end of treatment, significant (P < 0.05) reductions in systolic, diastolic and mean blood pressure, UAE and TGF beta1 levels were observed in all the groups. No change in renal function measurements were observed. The absolute and percentage reduction in UAE and TGF beta1 were significantly higher in the combined group than in the losartan or ramipril groups. No significant changes in absolute and percentage reduction of systolic, diastolic and mean blood pressure were found. All treatment regimens were well tolerated with few and transient side-effects.

CONCLUSION

These data indicate an additional renoprotective effect of dual blockade of the renin-angiotensin system (RAS) in hypertensive patients with minor renal abnormalities. In addition, the contemporaneus and marked decrease in TGF beta1 and UAE levels in hypertensives treated with combined therapy might indicate the presence of a subset of subjects who may benefit from complete RAS blockade.

Effect of successful hypertension control by manidipine or lisinopril on albuminuria and left ventricular mass in diabetic hypertensive patients with microalbuminuria

OBJECTIVE

The aim of this open-labelled, randomised, parallel-group study was to evaluate the effect of long-term monotherapy with manidipine or lisinopril on albumin excretion rate (AER) and left ventricular mass index (LVMI) in hypertensive patients with type-2 diabetes and microalbuminuria.

METHODS

After a 4-week wash-out period, 174 patients with essential hypertension [diastolic blood pressure (DBP) >80 mmHg and <100 mmHg], type-2 diabetes and microalbuminuria were randomised to manidipine 10 mg o.d. or lisinopril 10 mg o.d.; after 8 weeks, the dose was doubled in non-responders (DBP >80 mmHg); after 3 months, treatment was discontinued in the non-responder patients and in those complaining of side effects; the remaining 121 patients continued their therapy with manidipine or lisinopril, and 99 completed the 2-year study. At the end of the wash-out period, of the titration period and after 6, 12, 18 and 24 months of treatment, BP was measured, AER, creatinine clearance, glycosylated haemoglobin (HbA1c) and body mass index (BMI) were evaluated and an echocardiographic evaluation was performed.

RESULTS

The 99 patients who completed the study were statistically analysed according to a per-protocol evaluation. Manidipine and lisinopril significantly reduced systolic blood pressure (SBP) and DBP levels (at 24 months, --22.3/15.5 mmHg, P<0.001 versus baseline and --21.4/15.7 mmHg, P<0.01 versus baseline, respectively). Both drugs provided a significant decrease in AER, but it was significantly more pronounced with lisinopril (at 24 weeks, --37.2 mg/24 h, P<0.001 versus baseline) than with manidipine (--29.9 mg/24 h, P<0.05 versus baseline) and became evident earlier in the lisinopril group (after 3 months versus 6 months of treatment). Manidipine produced a greater reduction of LVMI than lisinopril (--14.9 g/m(2) versus --10.8 g/m(2) at 24 months). The effect was more pronounced in patients with left ventricular hypertrophy at baseline (--19.8 g/m(2) versus --12.8 g/m(2), P<0.05).

CONCLUSION

These data suggest that, despite similar BP lowering, non-haemodynamic factors play an important role in the pharmacological reduction of AER and LVMI in diabetic hypertensive patients.

Angiotensin-converting enzyme inhibitors in the therapy of renal diseases

Renal diseases, especially chronic renal failure (CRF), are common in canine and feline medicine. The renin-angiotensin-aldosterone system (RAAS) plays a pivotal role in these conditions in the development of renal lesions and the progression of kidney dysfunction. Angiotensin-converting enzyme inhibitors (ACEI) are currently considered as the most efficient agents in therapeutic strategies. The benefit of an ACEI treatment can be explained by at least three mechanisms: ACEI limit systemic and glomerular capillary hypertension, have an antiproteinuric effect, and retard the development of glomerulosclerosis and tubulointerstitial lesions. These effects have been studied in dogs and cats, and there is now some evidence to support the recommendation of ACEI therapy in dogs and cats with CRF. Nevertheless the prescription of ACEI in such patients should take into account the potential influence of renal impairment on ACEI disposition, and adverse effects on the renal function itself (especially hypotension and acute reductions in glomerular filtration rate). The risk of drug interaction with diuretics, nonsteroidal anti-inflammatory drugs and anesthetics, should not be overestimated. Furthermore, hypotension may occur in patients on a low sodium diet.

Irbesartan: a review of its use in hypertension and in the management of diabetic nephropathy

Irbesartan (Avapro, Aprovel) is a potent and selective angiotensin II subtype 1 receptor antagonist indicated for use in patients with hypertension, including those with type 2 diabetes mellitus and nephropathy. Once-daily administration of irbesartan provided 24-hour control of blood pressure (BP). In patients with mild-to-moderate hypertension irbesartan was as effective as enalapril, atenolol and amlodipine, and more effective than valsartan in terms of absolute reduction in BP and response rates. Irbesartan produced a greater reduction in diastolic BP at trough than once-daily losartan, but had a smaller effect than olmesartan; the reduction in systolic BP achieved with irbesartan was similar or greater than that with losartan and similar to that seen with olmesartan. The combination of irbesartan with hydrochlorothiazide produced additive effects on BP reduction. Irbesartan also induced regression of left ventricular mass in patients with hypertension and left ventricular hypertrophy. In two large studies (IRbesartan MicroAlbuminuria type 2 diabetes mellitus in hypertensive patients [IRMA 2] and the Irbesartan Diabetic Nephropathy Trial [IDNT]) irbesartan exerted a renoprotective effect in hypertensive patients with type 2 diabetes at both the early and later stages of diabetic nephropathy. The renoprotective effect was at least partly independent of the BP-lowering effect. In the IRMA 2 trial, the proportion of patients progressing to overt nephropathy was significantly lower for recipients of irbesartan 300mg once daily than placebo. In patients with overt nephropathy in the IDNT, irbesartan 300mg once daily provided significantly greater renoprotection than amlodipine 10mg once daily or placebo. The relative risk of doubling of serum creatinine was significantly lower with irbesartan than amlodipine or placebo. Irbesartan is well tolerated in hypertensive patients, including those with type 2 diabetes and incipient or overt nephropathy. The overall incidence of adverse events with irbesartan was similar to that with placebo. Irbesartan was associated with a lower incidence of cough than enalapril and was not associated with ankle oedema or with any clinically significant drug interactions. In conclusion, irbesartan is a well tolerated and effective antihypertensive agent. It also slows the progression of renal disease in hypertensive patients with type 2 diabetes at both the early and later stages of diabetic nephropathy. Thus, irbesartan is a valuable agent in the management of patients with these indications.

Hypertension in people with Type 2 diabetes: knowledge-based diabetes-specific guidelines

The International Diabetes Federation (Europe) has updated these guidelines on hypertension management specifically in Type 2 diabetes in the light of recent results of the first prospective, randomized controlled studies to investigate clinical outcomes in people with diabetes and hypertension. The guidelines are knowledge based, i.e. based not only on evidence originating from clinical trials, but also from epidemiological and pathophysiological studies. A successful management strategy requires the following components: 1. Regular surveillance to detect developing hypertension and other cardiovascular (CV) risk factors. 2. Considering more frequent monitoring and review of CV risk factors if any single blood pressure (BP) measurement > 140/85 mmHg (or 130/75 if microalbuminuria); when appropriate, using ambulatory or home monitoring to establish the baseline BP. 3. Considering other CV risk factors, such as a raised albumin excretion rate, in setting the intervention threshold. 4. Individualizing the target BP in accordance with other CV risk factors. 5. Agreeing lifestyle and therapeutic interventions with the patient, with education and empowerment as required. 6. Implementing lifestyle modifications, including controlling calorie, salt and alcohol intake, increased physical activity, weight control and smoking cessation. 7. Therapeutic strategy: the primary goal of therapy is to reduce BP markedly. Combination therapy is often necessary, e.g. an angiotensin converting enzyme (ACE) inhibitor and a diuretic. Some classes are particularly useful for certain patients, notably longer-acting ACE inhibitors, angiotensin 2 receptor antagonists (A2RAs) and calcium antagonists in those at risk of diabetic nephropathy, loop diuretics and thiazides in those at risk of hyperkalaemia, beta-blockers and calcium antagonists (except short-acting dihydropyridines) in patients with angina, beta-blockers and ACE inhibitors after a myocardial infarction or in those with left ventricular dysfunction, and thiazide diuretics and long-acting dihydropyridine calcium antagonists for isolated systolic hypertension. A2RAs should be particularly considered when ACE inhibitors are not tolerated. alpha 1-Blockers should not be considered first line in the absence of outcome data. Cost of drugs will modify these strategies in developing countries. 8. Monitoring response to therapies and, if target levels are not achieved, either intensifying drug therapy if the CV risk justifies it, or reassessing the target. 9. Maintaining a quality assurance strategy. This strategy is summarized in a simple, practical management algorithm.

Long-term antiproteinuric and renoprotective efficacy and safety of losartan in children with proteinuria

BACKGROUND

Angiotensin receptor antagonists are effective in reducing proteinuria by an action independent of blood pressure. As a consequence, such agents retard progressive renal dysfunction in adults with chronic proteinuria. Long-term efficacy and tolerability data in children are unavailable.

METHODS

Efficacy of losartan in reducing proteinuria and in preserving renal function was prospectively assessed in 52 consecutive children under 18 years of age with chronic proteinuric renal disorders, an initial creatinine clearance > or =25 mL/min/1.73 m(2), and a minimum of two or more follow-up visits. Thirty had proteinuria (P), and 22 had proteinuria combined with hypertension (P+H). Adverse effects were also evaluated.

RESULTS

Proteinuria had persisted or increased during a mean interval of 8.5 months before initiation of losartan at a mean dosage of 0.8 mg/kg/d. Mean protein excretion before starting losartan was 2453 mg/m(2)/d and fell by 34% at a mean follow-up time of six weeks (visit I, P<.05), and between 64% and 67% at mean follow-up periods of 0.38, 0.71, and 2.48 years corresponding to visits II, III, and IV (all P<.001 compared with baseline). The proportion of children with protein excretion exceeding 40 mg/m(2)/h (nephrotic range proteinuria) or nephrotic syndrome (>3500 mg/1.73 m(2)/d) fell from 42% and 40% at the start, to 24% and 8%, respectively, at visit IV (P<.01). Mean creatinine clearance as well as serum potassium and total CO(2) levels remained unchanged during the time of follow-up. Reduction in proteinuria in the P subgroup alone correlated with lowering in diastolic blood pressure at visit II and with both diastolic and systolic blood pressure at visits III and IV (all P<.05); it was largely independent of reduction in blood pressure in the P+H subgroup. The concomitant use of immunosuppressive agents in 28 of the 52 children had an influence on proteinuria only at baseline and at visit I (P<.05). There was no significant change in height or body mass index Z scores. Thirteen children had adverse effects potentially ascribed to losartan; most of these either improved or resolved with dosage adjustment or resulted in its discontinuation in 9 of the 52 children (17%).

CONCLUSION

Losartan therapy was associated with a marked and sustained reduction in proteinuria and in preservation of GFR in children with chronic proteinuric disorders. The association between proteinuria and systemic blood pressure reduction was complex: it was largely limited to the first year of losartan therapy and was more pronounced in the normotensive subgroup. Losartan was generally well tolerated.

Inflammation and angiotensin II

Angiotensin II (AngII), the major effector peptide of renin-angiotensin system (RAS), is now recognized as a growth factor that regulates cell growth and fibrosis, besides being a physiological mediator restoring circulatory integrity. In the last few years, a large number of experimental studies has further demonstrated that AngII is involved in key events of the inflammatory process. Here, we summarize the wide variety of AngII functions and discuss them in relation with the inflammatory cascade. AngII increases vascular permeability (via the release of prostaglandins and vascular endothelial cell growth factor or rearrangement of cytoskeletal proteins) that initiates the inflammatory process. AngII could contribute to the recruitment of inflammatory cells into the tissue through the regulation of adhesion molecules and chemokines by resident cells. Moreover, AngII could directly activate infiltrating immunocompetent cells, including chemotaxis, differentiation and proliferation. Recent data also suggest that RAS activation could play a certain role even in immunologically-induced inflammation. Transcriptional regulation, predominantly via nuclear factor-kappaB (NF-kappaB) and AP-1 activation, and second mediator systems, such as endothelin-1, the small G protein (Rho) and redox-pathways are shown to be involved in the molecular mechanism by which AngII exerts those functions. Finally, AngII participates in tissue repair and remodeling, through the regulation of cell growth and matrix synthesis. In summary, recent data support the hypothesis that RAS is key mediator of inflammation. Further understanding of the role of the RAS in this process may provide important opportunities for clinical research and treatment of inflammatory diseases.

Mesangial cell proliferation inhibitors for the treatment of proliferative glomerular disease

Mesangial cells (MC) serve a number of functions in the renal glomerular capillary including structural support of the capillary tuft, modulation of glomerular hemodynamics, and a phagocytic function allowing removal of macromolecules and immune complexes. The proliferation of MC is a prominent feature of glomerular disease including IgA nephropathy, membranoproliferative glomerulonephritis, lupus nephritis, and diabetic nephropathy. In experimental animal models of nephritis, MC proliferation frequently precedes and is linked to the increase of extracellular matrix in the mesangium and glomerulosclerosis. Reduction of MC proliferation in glomerular disease models by treatment with heparin, low-protein diet, or antibodies to platelet-derived growth factor (PDGF), have been shown to reduce extracellular matrix expansion and glomerulosclerotic changes. Therefore, MC proliferation inhibitors may offer therapeutic opportunities for the treatment of proliferative glomerular disease. It is also known that the MC proliferation is inhibited by many kinds of pharmacological drugs, for example, angiotensin converting enzyme (ACE) inhibitors, leukotriene D(4) (LTD(4)) antagonists, PDGF inhibitors, matrix metalloproteinases (MMP) inhibitors, 3-hydroxy-3 methyl glutaryl-coenzymeA (HMG-CoA) inhibitors, cyclin-dependent kinases (CDK) inhibitors, and others. This review summarizes the recently reported MC proliferation inhibitors with their pharmacological properties on the basis of their chemical structures.

Effects of enalapril and eprosartan on the renal vascular nitric oxide system in human essential hypertension

BACKGROUND

Experimental data in humans on the contribution of angiotensin-converting enzyme inhibitors and angiotensin II type 1 receptor blockers to the nitric oxide system of the renal vasculature are inconsistent. Enalapril and eprosartan, alone and in combination, were used to determine their short-term effects on the renal nitric oxide system and renal hemodynamics of human subjects with essential hypertension.

METHODS

Twenty male, white patients (27 +/- 1 years) with mild essential hypertension (143 +/- 11/95 +/- 6 mm Hg) were included in a double-blind, randomized, placebo-controlled, fourfold cross-over study with placebo, enalapril (20 mg/day), eprosartan (600 mg/day), or combination of both drugs (10 and 300 mg/day, respectively) each over a one week period followed by a two-week washout phase. After each study phase the glomerular filtration rate (GFR) and renal plasma flow (RPF) were determined. Basal nitric oxide synthesis of the renal vasculature was assessed by the decrease in RPF after inhibition of nitric oxide synthase with NG-monomethyl-L-arginine (L-NMMA; 4.25 mg/kg).

RESULTS

After one week of therapy, the combination therapy decreased casual blood pressure by 5 +/- 2/3 +/- 1 mm Hg versus placebo (P < 0.01). Neither enalapril alone (-2 +/- 2/1 +/- 2 mm Hg, NS vs. placebo) nor eprosartan alone (-1 +/- 1/0 +/- 2 mm Hg, NS vs. placebo) had a clear-cut significant effect on casual blood pressure. In the combination phase, RPF increased by 123 +/- 36 mL/min (P < 0.01). Neither enalapril alone (+59 +/- 46 mL/min, P = 0.21) nor eprosartan alone (+113 +/- 51 mL/min, P = 0.06) had a clear-cut significant effect on RPF. Changes of RPF induced by treatment correlated with the L-NMMA induced decrease in RPF in the combination (r = 0.70, P < 0.01) and eprosartan phase (r = 0.86, P < 0.001), but not in the enalapril phase (r = -0.44, P = 0.10). Renal vascular resistance was reduced by each active treatment with the most prominent reduction in the combination phase. GFR was unaffected by any treatment.

CONCLUSIONS

In contrast to the effects of either substance alone, a combination of half the dose of eprosartan with half the dose of enalapril had a prominent effect on renal perfusion. The effects of eprosartan on RPF are mediated, at least in part, by an increased bioavailability of nitric oxide in the renal vasculature.

Manidipine: a review of its use in hypertension

Manidipine is a dihydropyridine calcium antagonist, which causes systemic vasodilation by inhibiting the voltage-dependent calcium inward currents in smooth muscle cells. The resulting reduction in blood pressure (BP) in patients with hypertension is maintained over 24 hours. Manidipine 10 to 40 mg once daily for 4 weeks significantly lowered office BP from baseline and compared with placebo, and significantly reduced 24-hour BP compared with placebo in patients with essential hypertension in a well controlled trial. The decline in BP was maintained over 24 hours (trough to peak BP ratios were >50%) without disturbing the circadian BP pattern. BP reductions with therapeutic dosages of manidipine were maintained for up to 1 year in noncomparative trials. The BP-lowering capacity of manidipine 5 to 20 mg/day appears to be similar to that of other calcium antagonists with which it has been compared in randomised double-blind and nonblind trial. In a well controlled short term trial, manidipine 10 mg daily significantly decreased trough sitting BP compared with placebo in elderly patients with mild to moderate essential hypertension. Decreases in BP were maintained for up to 3 years of treatment. The drug (10 or 20 mglday) also significantly lowered sitting BP from baseline in patients with hypertension and type 2 diabetes mellitus in randomised, long term comparative trials. In general, the observed reduction in BP with manidipine was similar to that observed with amlodipine, enalapril or delapril. The effects of manidipine on urinary albumin excretion (UAE) have not been clearly demonstrated in clinical trials in this patient group. BP was also reduced with manidipine in patients with impaired glucose tolerance. Manidipine was well tolerated in clinical trials, with most adverse effects related to vasodilation. Commonly reported events included ankle oedema, headache. palpitation. flushing, dizziness, rash and fatigue. Manidipine appears to have less potential for pedal oedema than amlodipine.

CONCLUSIONS

Manidipine has shown antihypertensive efficacy and appears to be well tolerated in adult and elderly patients with mild or moderate essential hypertension. The BP-lowering effects of the drug in patients with hypertension and type 2 diabetes mellitus or impaired glucose tolerance were not associated with any adverse metabolic effects. The effects of manidipine on UAE in this patient group remain unclear. Manidipine provides an additional treatment option for patients for whom dihydropyridine calcium antagonists are appropriate. Manidipine is a dihydropyridine calcium antagonist, which causes systemic vasodilation by inhibiting the voltage-dependent calcium inward currents in smooth muscle cells. The resulting reduction in blood pressure (BP) in patients with hypertension is maintained over 24 hours. Manidipine 10 to 40mg once daily for 4 weeks significantly lowered office BP from baseline and compared with placebo, and significantly reduced 24-hour BP compared with placebo in patients with essential hypertension in a well controlled trial. The decline in BP was maintained over 24 hours (trough to peak BP ratios were >50%) without disturbing the circadian BP pattern. BP reductions with therapeutic dosages of manidipine were maintained for up to 1 year in non-comparative trials. The BP-lowering capacity of manidipine 5 to 20 mg/day appears to be similar to that of other calcium antagonists with which it has been compared in randomised double-blind and nonblind trial. In a well controlled short term trial, manidipine 10 mg daily significantly decreased trough sitting BP compared with placebo in elderly patients with mild to moderate essential hypertension. Decreases in BP were maintained for up to 3 years of treatment. The drug (10 or 20 mg/day) also significantly lowered sitting BP from baseline in patients with hypertension and type 2 diabetes mellitus in randomised, long term comparative trials. In general, the observed reduction in BP with manidipine was similar to that observed with amlodipine, enalapril or delapril. The effects of manidipine on urinary albumin excretion (UAE) have not been clearly demonstrated in clinical trials in this patient group. BP was also reduced with manidipine in patients with impaired glucose tolerance. Manidipine was well tolerated in clinical trials, with most adverse effects related to vasodilation. Commonly reported events included ankle oedema, headache. palpitation. flushing, dizziness, rash and fatigue. Manidipine appears to have less potential for pedal oedema than amlodipine.

CONCLUSIONS

Manidipine has shown antihypertensive efficacy and appears to be well tolerated in adult and elderly patients with mild or mo

Drug use in renal failure

A number of medications used in the presence of renal disease require dose adjustments be made. The health care professional should know a drug's route of elimination, the percentage of protein binding, and the percentage of a normal dose removed by dialysis. This information is a guideline and should be used to start therapy. The clinician must understand that individual adjustments are the rule rather than the exception.

High serum enalaprilat in chronic renal failure

BACKGROUND

Most angiotensin-converting enzyme (ACE) inhibitors and their metabolites are excreted renally and doses should hence be reduced in renal insufficiency. We studied whether the dosage of enalapril in daily clinical practice is associated with drug accumulation of enalaprilat in chronic renal failure.

METHODS

Fifty nine out-patients with plasma creatinine >150 micromol/L and chronic antihypertensive treatment with enalapril were investigated, in a cross-sectional design.

RESULTS

Median glomerular filtration rate (GFR) was 23(range 6-60) ml/minute/1.73 m2. The daily dose of enalapril was 10 (2.5-20) mg and the trough serum concentration of enalaprilat was 31.8 (<2.5-584.7)ng/ml. Ninety percent of the patients had higher serum concentrations of enalaprilat than has been reported in subjects with normal kidney function, and a marked elevation of serum enalaprilat was observed in patients with GFR <30 ml/minute. All but three patients had serum ACE activity below the reference range. The ACE genotype did not influence the results. Additional pharmacokinetic studies were done in nine patients in whom GFR was 23 (10-42)ml/minute/1.73 m2. The median clearance of enalaprilat was 28 (16-68) ml/minute and correlated linearly with GFR (r=0.86, p=0.003). Intra-subject day-to-day variation in trough concentrations was 19.7%.

CONCLUSION

Patients with chronic renal failure given small or moderately high doses of enalapril may thus have markedly elevated levels of serum enalaprilat. Whether this affords extra renoprotection, or on the contrary may inappropriately impair renal function, is not known, and should be investigated in prospective, controlled studies.

Renal tubulointerstitial damage caused by persistent proteinuria is attenuated in AT1-deficient mice: role of endothelin-1

Using angiotensin II (AngII) type 1A receptor-deficient mice [AT1(-/-)], in which we induced protein overload nephropathy, we explored the potential implication of AngII and endothelin-1 (ET-1) in the tubulointerstitial damage because of persistent proteinuria. At day 7, AT1(-/-) showed marked proteinuria to a similar extent to that of wild-type mice (WT). However, at day14, AT1(-/-) had significantly less proteinuria, renal damage, transforming growth factor-beta, and matrix mRNA expression and mortality. AT1(-/-) also showed a significant diminution in the activation of the transcriptional factors nuclear factor-kappaB and AP-1. Unexpectedly, AT1(-/-) had a higher interstitial infiltration than WT. The administration of the angiotensin-converting enzyme inhibitor quinapril to WT caused a marked improvement in proteinuria and renal lesions, resembling that seen in untreated AT1(-/-). However, the interstitial infiltration persisted in AT1(-/-) when treated with quinapril. Because ET-1 may participate in the recruitment of mononuclear cells, we also studied the implication of this peptide. AT1(-/-) had a significantly higher ET-1 expression in tubular epithelial cells than WT. The administration of the dual ETA/ETB antagonist bosentan to AT1(-/-) considerably reduced the interstitial infiltrates. Bosentan also exerted a beneficial effect on proteinuria, renal lesions, and mortality in WT. These data show that in overload nephropathy, proteinuria and renal lesions are, to a large extent, AngII-dependent. The up-regulation of ET-1 in tubular epithelial cells in AT1(-/-), associated with interstitial infiltrates, suggests that the combination of drugs interfering with both vasopeptides may be of therapeutic interest in renal diseases with severe proteinuria and tubulointerstitial damage.

Angiotensin receptor blockers: evidence for preserving target organs

Hypertension is a major problem throughout the developed world. Although current antihypertensive treatment regimens reduce morbidity and mortality, patients are often noncompliant, and medications may not completely normalize blood pressure. As a result, current therapy frequently does not prevent or reverse the cardiovascular remodeling that often occurs when blood pressure is chronically elevated. Blockade of the renin-angiotensin system (RAS) is effective in controlling hypertension and treating congestive heart failure. Both angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) inhibit the activity of the RAS, but these two classes of antihypertensive medications have different mechanisms of action and different pharmacologic profiles. Angiotensin-converting enzyme inhibitors block a single pathway in the production of angiotensin II (Ang II). In addition, angiotensin I is not the only substrate for ACE. The ACE inhibitors also block the degradation of bradykinin that may have potential benefits in cardiovascular disease. Bradykinin is, however, the presumed cause of cough associated with ACE inhibitor therapy. Data from clinical trials on ACE inhibitors serve to support the involvement of the RAS in the development of cardiovascular disease. Angiotensin receptor blockers act distally in the RAS to block the Ang II type 1 (AT1) receptor selectively. Thus, ARBs are more specific agents and avoid many side effects. Experimental and clinical trials have documented the efficacy of ARBs in preserving target-organ function and reversing cardiovascular remodeling. In some instances, maximal benefit may be obtained with Ang II blockade using both ARBs and ACE inhibitors. This review describes clinical trials that document the efficacy of ARBs in protecting the myocardium, blood vessels, and renal vasculature.

Cost effectiveness of ramipril in patients with non-diabetic nephropathy and hypertension: economic evaluation of Ramipril Efficacy in Nephropathy (REIN) Study for Germany from the perspective of statutory health insurance

BACKGROUND

In the Ramipril Efficacy In Nephropathy (REIN) trial, ramipril significantly lowered the rate of reaching the combined end-point of doubling of baseline serum creatinine levels or end-stage renal failure (ESRF).

OBJECTIVE

To determine the additional cost per patient-year of chronic (long term) dialysis avoided (PYCDA) when the ACE inhibitor, ramipril, was added to conventional treatment of patients with non-diabetic nephropathy and hypertension.

STUDY PERSPECTIVE

Statutory Health Insurance (SHI) provider in Germany.

DESIGN AND SETTING

Data from the REIN Study were used in a cost-effectiveness analysis (CEA). A modelling approach was used, which was based on secondary analysis of published data, and costs were those incurred by the SHI provider (i.e. SHI expenses). In the base-case analysis, average case-related SHI expenses were applied and PYCDA were quantified using the cumulative incidence of ESRF as observed in the REIN trial.

MAIN OUTCOME MEASURES AND RESULTS

The incremental cost-effectiveness ratios (ICERs) of ramipril varied between about -76,700 deutschmarks (DM) and -DM81,900 per PYCDA (DM 1 approximately equals 0.55 US dollars; 1999 values), according to the treatment periods of 1 year and 3 years, respectively. In the sensitivity,analysis, the robustness of the model and its results were shown when the extent of influence of different model variables on the base-case results was investigated. First, probabilities of ESRF and PYCDA were estimated according to the Weibull method. Second, the influence of the model variables on the target variable was quantified using a deterministic model. Third, the dependency of the target variable (ICER) on random variables was described in a simulation. The cost for chronic dialysis had by far the greatest impact on the target variable, which was 28 times greater than the impact of clinical effectiveness of ramipril, i.e. the number of PYCDA. There were net savings per PYCDA with ramipril treatment after 1, 2 and 3 years: 95% of the 10,000 simulation steps resulted in savings of between DM69 500 and D94,600 per PYCDA after 3 years.

CONCLUSIONS

Results from this evaluation show that ramipril offers enormous savings from the perspective of the SHI provider (third-party payer) in Germany when added to the conventional treatment of patients with non-diabetic nephropathy and hypertension.

Long-term comparison of losartan and enalapril on kidney function in hypertensive type 2 diabetics with early nephropathy

BACKGROUND

The objectives of this study were to compare the effects of the angiotensin II receptor blocker, losartan, to those of the angiotensin-converting enzyme inhibitor, enalapril, on albuminuria and renal function in relationship to clinic and ambulatory blood pressure (ABP) in hypertensive type 2 diabetic subjects with early nephropathy. The tolerability of these agents and their effect on the metabolic profile were also evaluated.

METHODS

The study was a one-year prospective, double-blind trial with losartan and enalapril administered alone or in combination with hydrochlorothiazide and other antihypertensive agents. ABP and renal and biochemical parameters were measured at baseline and after 12, 28, and 52 weeks of active treatment. Ninety-two hypertensive type 2 diabetics with early nephropathy completed the study.

RESULTS

Both losartan and enalapril administered alone or in combination with other agents induced significant reductions in sitting clinic (P < 0.05) and ABP (P < 0.002) without a statistical difference between groups. Geometric means for urinary albumin excretion (UAE) decreased significantly (P < 0.001) in patients treated with losartan from 64. 1 to 41.5 microg/min and in those treated with enalapril from 73.9 to 33.5 microg/min after 52 weeks of therapy. A significant relationship (P < 0.05) between changes in systolic and diastolic ABP and the decrease in UAE at 52 weeks was seen in both groups. The decline in glomerular filtration rate (GFR) was stabilized at the end of therapy and was identical in both treatment groups. Treatment with enalapril was associated with a significantly higher incidence of cough (P = 0.006) and a rise in serum uric acid (P = 0.002) compared with losartan.

CONCLUSIONS

Our results indicate that a one-year course of antihypertensive therapy with either losartan or enalapril significantly reduces UAE in hypertensive type 2 diabetic patients with early nephropathy. The reduction in UAE with each treatment is similarly related to decrements in ABP. In addition, the rate of decline in GFR is similar in both treatment groups.