Renoprotective role of ACE inhibitors in diabetic nephropathy

Induction of PDCD4 by albumin in proximal tubule epithelial cells potentiates proteinuria-induced dysfunctional autophagy by negatively targeting Atg5

The precise molecular mechanism of autophagy dysfunction in type 1 diabetes is not known. Herein, the role of programmed cell death 4 (PDCD4) in autophagy regulation in the pathogenesis of diabetic kidney disease (DKD) in vivo and in vitro was described. It was found that Pdcd4 mRNA and protein was upregulated in the streptozotocin (STZ)-induced DKD rats. In addition, a unilateral ureteral obstruction mouse model displayed an upregulation of PDCD4 in the disease group. kidney biopsy samples of human DKD patients showed an upregulation of PDCD4. Furthermore, western blotting of the STZ-induced DKD rat tissues displayed a low microtubule-associated protein 1A/1B-light chain 3 (LC3)-II, as compared to the control. It was found that albumin overload in cultured PTEC could upregulate the expression of PDCD4 and p62, and decrease the expression of LC3-II and autophagy-related 5 (Atg5) proteins. The knockout of Pdcd4 in cultured PTECs could lessen albumin-induced dysfunctional autophagy as evidenced by the recovery of Atg5 and LC3-II protein. The forced expression of PDCD4 could further suppress the expression of crucial autophagy-related gene Atg5. Herein, endogenous PDCD4 was shown to promote proteinuria-induced dysfunctional autophagy by negatively regulating Atg5. PDCD4 might therefore be a potential therapeutic target in DKD.

An encounter with enalapril-induced resistant, life-threatening angioedema at rural health center in Botswana

Angioedema, a rare, potentially fatal and usually self-limiting adverse effect of therapy with enalapril, is always a challenging encounter for an intensive care specialist in a rural setup. Here, we present a 74-year-old female, who presented to the Emergency Department of Sekgoma Memorial Hospital, Serowe village, Botswana, with progressive swelling of her face, tongue and breathing difficulty just 2 days after starting tablet enalapril. She failed to respond to usual treatment with adrenaline, steroids, and H1-antihistaminic agent, but she responded well with intravenous fresh-frozen plasma infusion. This helped us manage a difficult airway situation in a less equipped rural health center.

What are the most effective interventions in preventing diabetic foot ulcers?

Although many studies have shown strong associations between certain causal factors and patients with foot ulcers, it is unclear how many of these factors interact. A model that could help identify unique causal pathways and pivotal factors associated with the development of foot ulcers may lead to earlier intervention as well as less frequent and less severe complications. Therefore, the purpose of this study was to identify the responsible causal pathways associated with foot ulcers in persons with diabetes, to determine the frequency of components of the pathway and to identify pivotal events of the pathway. Eighty-seven patients with 103 existing or recently healed ulcers were prospectively evaluated. The data used in the pathway analysis reflected seven variables that have been associated with the development of foot ulcers. The data were interpreted to assess which component causes and pivotal events were responsible for the present ulcer. A cluster analysis was used to confirm findings from the descriptive analysis. Twenty-four pathways were identified. The seven most common unique pathways accounted for 64.1% of the cases. The results of the cluster analysis showed four consistent, dominant clusters: (i) neuropathy, deformity, callus and elevated peak pressure; (ii) peripheral vascular disease; (iii) penetrating trauma and (iv) Ill-fitting shoe gear. These results suggest that there is a finite number of key factors that, if identified and addressed with appropriate intervention strategies, may reduce the risk for the cascade of events towards ulceration and subsequent amputation.

Brief review: angiotensin converting enzyme inhibitors and angioedema: anesthetic implications

PURPOSE

Angiotensin converting enzyme inhibitors (ACEIs) are a group of drugs used to treat hypertension and heart failure, with additional benefits, such as cardiovascular and renal protection, in patients with diabetes. However, angioedema as a complication of ACEI therapy is under-recognized. As there are important implications for anesthesiologists and emergency medicine physicians, a review was undertaken to document the scope of the problem of ACEI-induced angioedema..

METHODS

A review of the published literature (identified by searching Medline, EMBASE and CINAHL) was undertaken, addressing the clinical uses of ACEIs and the incidence, risk factors, pathophysiology, clinical presentation and management of angioedema associated with the use of these drugs.

PRINCIPAL FINDINGS

The incidence of ACEI related angioedema has increased from 0.1-0.2% to 1% over the last decade. Patients who are receiving ACEIs are predisposed to developing angioedema which may be triggered by trauma, airway instrumentation, infection, and irritant fumes, particularly in those who are at increased risk. Cases of acute facial and airway oedema, due to ACEI drug administration, may be misdiagnosed as an anaphylactic reaction, and the association with ACEIs may be ignored. Some cases of intraoperative and postoperative airway edema may be precipitated by airway instrumentation in patients receiving ACEI drugs. The severity of airway compromise ranges from mild facial edema to severe laryngeal or subglottic edema which may prove life-threatening.

CONCLUSION

In view of the widespread clinical indications and ever-increasing use of ACEI drugs, the potentially life-threatening adverse reaction of ACEI-associated angioedema, and its treatment, must be recognized by anesthesiologists and all clinicians involved in airway management.

Diabetes and hypertension, the deadly duet: importance, therapeutic strategy, and selection of drug therapy

Large, placebo-controlled RCTs that involve only diabetic patients who have hypertension have not been performed. Subgroup analyses of hyper-tension control from several recent RCTs un-equivocally demonstrated greater benefit in diabetic populations (see Table 3) with ACE inhibitors, TDs, and CCBs. Treatment with fBs(atenolol) also was beneficial in diabetic patients who had hypertension in the actively-controlled UKPDS. The results of three RCTs support intensive BP control in diabetic patients (see Table 4). In these trials, diabetic patients gained more benefit than nondiabetic patients. Such an effect is consistent with the fact that diabetics are at higher risk for CV events. Although there are limited data from RCTs with head-to-head comparison of newer agents (eg,ACE inhibitors, ARBs, CCBs) to show that these drugs are better than diuretics and betaBs in reducing CV events by treating hypertension in the diabetic population, the available data support ACE inhibitors (and ARBs if ACE inhibitors are not tolerated) as an initial drug of choice in diabetic,hypertensive patients (see Table 5). Most diabetic patients require three or four drugs to control their BP to target range; as such, it is not necessary to justify the choice of any single class of drug. Tight BP control is cost-effective and is more rewarding than hyperglycemic control in diabetic,hypertensive patients. The optimal goal in diabetics should be to achieve BP that is less than 130/80 mm Hg. Appropriate action should be taken if BP is greater than 140/85 mm Hg. In subjects who have diabetes and renal insufficiency,the BP should be decreased to less than 125/75 mm Hg to delay the progression of renal failure. Limited data suggest that an ACE inhibitor or an ARB is the agent of choice, especially in patients who have proteinuria or renal insufficiency. betaBs can be the first-line agent in diabetics who have CAD. TDs and CCBs are the second line drugs.AAAs should be avoided. Most hypertensive patients require more than one agent to adequately control their BP. There is no evidence to support one combination regimen over the others, nevertheless, the combination of an ACE inhibitor with a TD or a fPB may be more beneficial and cost effective than other combinations in the diabetic population. Large outcome studies that compare different combination therapies in hypertensive,diabetic patients are needed.

Airway Compromise Due to Angiotensin-Converting Enzyme Inhibitor-Induced Angioedema

STUDY OBJECTIVE

To evaluate the incidence of airway compromise, clinical presentation and morbidity of angiotensin-converting enzyme inhibitor (ACEI)-related angioedema (AE).

METHOD

A retrospective chart review was conducted of all patients admitted to our hospital between 1996 and 2001 with the diagnosis of AE.

RESULTS

A total of 70 charts on which a diagnosis of AE had been entered were reviewed. Of those, 45 patients (64%) had AE that was thought to be related to ACEI therapy. Of those 45 patients, 29 were women. The mean age was 62 years, and 41 (91%) were African-American. The duration of ACEI therapy before presentation varied from 1 day to 5 years postingestion. Twenty-one of 32 patients presented within 2 months of the initiation of therapy. The mean duration between the onset of symptoms and presentation to the hospital was 9 h. Lip and tongue swelling was seen in all patients. Pulmonary manifestations were noted in 17 of 45 patients (38%) [dyspnea 17 of 17 patients; stridor/respiratory failure, 5 of 17 patients; cough, 2 of 17 patients]. Dysphagia was noted in 9 of 45 patients, drooling of saliva in 8 of 45 patients, and pruritus in 6 of 45 patients. Ten of 45 patients had a history of AE. In five of those patients (50%), ACEI use was a presumed cause of the AE for the current hospital admission. Eighteen of 45 (40%) patients required ICU admission. The mean ICU length of stay was 2.2 days. Five of 45 patients required endotracheal intubation. The mean time spent receiving ventilation was 2.2 days. Discontinuation of the initiating agent and supportive care were the keys to therapy. All of our patients responded to supportive management, and there was no mortality.

CONCLUSION

Sixty-four percent of patients in this series had AE due to receiving an ACEI. The majority of the patients were African-American women. Most patients presented within 2 months of starting to receive the drug, although longer durations of therapy were not uncommon. Lip and tongue swelling was the most common airway manifestation. Based on our observations, the discontinuation of ACEI therapy and supportive management are the recommended approaches to therapy to prevent an untoward outcome.

The role of angiotensin II receptor antagonists in the management of diabetes

Diabetic nephropathy, which develops in about 30% of patients with diabetes, is a progressive condition. It is characterized by increased blood pressure, declining glomerular filtration rate and albuminuria. Lowering of blood pressure in diabetic patients is associated with reduced cardiovascular risk and renal protection. Inhibitors of angiotensin-converting enzyme (ACE) are the current gold standard treatment for hypertension in patients with type I diabetes because, in addition to their blood pressure lowering ability, they are thought to oppose the increased intraglomerular pressure that is mediated in part by angiotensin II. The angiotensin II receptor antagonists, a more recently developed class of antihypertensive agents, appear to be as effective as ACE inhibitors in delaying the progression of renal injury in animal models of diabetes. They act by selectively blocking the binding of angiotensin II to the AT1 receptor and may, therefore, offer a more complete blockade of the renin-angiotensin system than ACE inhibitors. The renal and antihypertensive effects of this class of drug in patients with diabetes are now being investigated in long-term clinical trials. The multicentre Diabetics Exposed to Telmisartan And EnalaprIL (DETAIL) study is a randomized, double-blind, parallel-group comparison of the renal and antihypertensive effects of the angiotensin II receptor antagonist telmisartan and the ACE inhibitor enalapril in 272 patients with type II diabetes. The primary outcome is change in glomerular filtration rate over the 5 years of the study.

Effectiveness of the diabetic foot risk classification system of the International Working Group on the Diabetic Foot

OBJECTIVE

To evaluate the effectiveness of a diabetic foot risk classification system by the International Working Group on the Diabetic Foot to predict clinical outcomes.

RESEARCH DESIGN AND METHODS

A total of 225 diabetic patients were initially evaluated as part of a prospective case-control study at the University of Texas Health Science Center at San Antonio. Complete records were available for 213 patients for follow-up evaluation after 29 months. Upon enrollment, subjects were stratified into four risk groups based on the presence of risk factors according to the consensus of the International Working Group on the Diabetic Foot. Group 0 consisted of subjects without neuropathy, group 1 consisted of patients with neuropathy but without deformity or peripheral vascular disease (PVD), group 2 consisted of subjects with neuropathy and deformity or PVD, and group 3 consisted of patients with a history of foot ulceration or a lower-extremity amputation.

RESULTS

Upon enrollment, patients in higher-risk groups had longer duration of diabetes, worse glycemic control, vascular and neuropathic variables, and more systemic complications of diabetes. During 3 years of follow-up, ulceration occurred in 5.1, 14.3, 18.8, and 55.8% of the patients in groups 0, 1, 2, and 3, respectively (linear-by-linear association, P < 0.001). All amputations were found in Groups 2 and 3 (3.1 and 20.9%, P < 0.001).

CONCLUSIONS

The foot risk classification of the International Working Group on the Diabetic Foot predicts ulceration and amputation and can function as a tool to prevent lower-extremity complications of diabetes.

Urinary albumin excretion rate and glomerular filtration rate in the prediction of diabetic nephropathy; a long-term follow-up study of childhood onset type-1 diabetic patients

BACKGROUND

Predictors of diabetic nephropathy are only partly known. The role of glomerular hyperfiltration is much discussed. We have studied the cumulative incidence of micro and macroalbuminuria and the predictive value of glomerular filtration rate (GFR) and screening value of albumin excretion rate (AER) in type-1 diabetes.

METHODS

A cohort of diabetic children was followed up at a mean duration of 29+/-3 years. All 75 children treated in one hospital with diabetes duration > or =8 years were prospectively followed for 8 years examining GFR, AER, blood pressure and HbA1c. After another 8-10 years, 60 of them were traced for endpoint follow-up.

RESULTS

Seven patients (12%) developed macroalbuminuria, i.e. persistent overnight AER>200 mg/min, 12 (20%) developed persistent microalbuminuria (AER 15-200 mg/min) and 17 (28%) transient microalbuminuria (>15 mg/min on two consecutive occasions, normalized at endpoint). One baseline screening value of 24-h AER>15 mg/min predicted 93% of patients with persistent micro or macroalbuminuria. The negative predictive value was 78%. Six of seven macroalbuminuric and 10 of 12 microalbuminuric patients had a baseline GFR above the normal limit of the method (> or =125 ml/min/1.73 m(2)). When adjusted for diabetes duration, increased GFR predicted macro or microalbuminuria (odds ratios=5.44, P=0.04). The positive predictive value for having an increased baseline GFR was 53%. The negative predictive value was 77%. Stratification for HbA1c did not change the effect of an increased GFR.

CONCLUSIONS

At a mean diabetes duration of 29 years the cumulative incidence of macroalbuminuria was 12%; however, another 20% had persistent microalbuminuria. A screening value of 24-h AER >15 mg/min was a strong predictor, whereas increased GFR was a weaker but significant predictor for micro and macroalbuminuria.

Characteristics of progressive renal disease

Virtually all renal diseases progress to terminal renal failure relatively independently of the initial disease. Arresting the rate of the deterioration of kidney failure has a great impact on reducing the number of patients reaching the stage of expensive renal replacement therapy. Understanding the mechanisms of the progression of kidney disease has greatly been improved during recent years. The nature of the progressive renal damage with various etiologies includes various well-known factors where hemodynamics, renin-angiotensin system (RAS) and progressive proteinuria play the central roles. Proteinuria has to be shown as an independent risk factor for renal disease progression. Also, disturbances in lipid metabolism as well as the later structural lesions contribute to the progression. Various modalities have been used for the prevention of progressive renal disease, e.g. low-protein diet, antihypertensive therapy, antifibrotic therapy. Many recent experimental and clinical studies have shown that besides the systemic blood pressure lowering effect, RAS blocking agents provide renal protective effects via direct, hemodynamic, and indirect, non-hemodynamic, pathways: (1) lowering intraglomerular capillary hydraulic pressure, and increasing the glomerular ultrafiltration coefficient; (2) lowering proteinuria; (3) lowering hyperlipidemia; (4) diminishing kidney growth; (5) diminishing infiltration of macrophages; (6) downregulation of proinflammatory cytokines. Therefore, RAS blocking agents are widely prescribed not only for antihypertensive but also for renoprotective purposes in diabetic and non-diabetic nephropathies.

Is there a critical level of plantar foot pressure to identify patients at risk for neuropathic foot ulceration?

The purpose of this study was to identify a point along the spectrum of peak plantar forefoot pressure that has an optimum combination of sensitivity and specificity to screen for neuropathic ulceration. We enrolled 219 diabetic patients in this case-control study in an approximate 2:1 control:case ratio. Cases were defined as patients with an active or recently healed neuropathic ulceration. Controls were defined as those with no history of ulceration. All patients had peak plantar pressures analyzed with the EMED gait analysis system. Peak plantar pressure was, as expected, significantly higher for patients with ulcers compared to controls [83.1 +/- 24.7 N/cm2 (range, 10-125) vs. 62.7 +/- 24.4 N/cm2 (range, 7.3-113), p < .001]. The ulcer group was clearly skewed toward a higher prevalence of elevated peak plantar forefoot pressure compared with the control group, which displayed the opposite trend (control group skewness = 0.286, kurtosis = -0.482; ulcer group skewness = -0.389, kurtosis = -0.289). Using receiver operating characteristic analysis, the optimal cut-point, as determined by a balance of sensitivity and specificity was 70 N/cm2, which yielded a sensitivity of 70.0% and a specificity of 65.1%. We concluded that, while there is no optimal cut-point for clearly screening patients for risk of foot ulceration, the higher the peak pressure, the higher the commensurate risk.

Dietary protein restriction in combination with angiotensin converting enzyme inhibitor improves insulin resistance in patients with chronic renal disease

Insulin resistance (IR) and secondary hyperinsulinaemia are major risk factors of atherosclerosis and probably also of related glomerulosclerosis. Angiotensin converting enzyme inhibitors (ACEI), while improving IR in essential hypertension, do not improve it in patients with chronic renal disease. Thus, the combination of ACEI and low protein diet was evaluated. Thirty-eight patients with various kidney diseases and mild to moderate impairment of kidney function were included in the study. Thirteen of them suffered from IR. Their dietary protein intake was decreased from > or = 1.0 g/kg/d to 0.6-0.7 g/kg/d. Moreover, they were treated by ACEI enalapril at dosages of 2-10 mg/d depending on the absence/presence and severity of hypertension. The patients were followed for 8 months. No clinically relevant kidney disease progression (KDP) was found. IR patients improved remarkably. IR was examined by the oral glucose tolerance test and glucose, insulin and C-peptide determinations. Their increased plasma triglyceride, VLDL concentrations and proteinuria decreased, HDL concentration increased. Acid-base balance and anaemia did not change. It is concluded that protein restriction in combination with ACEI treatment improve IR and the associated dyslipoproteinaemia and proteinuria.

Autonomy of the renin system in type II diabetes mellitus: dietary sodium and renal hemodynamic responses to ACE inhibition

Recognition that non-insulin-dependent diabetes mellitus (NIDDM) is a leading cause of end-stage renal disease (ESRD), and a focus of recent therapeutic and genetic studies on the renin system have rekindled interest in mechanisms by which angiotensin converting enzyme (ACE) inhibitors influence the diabetic kidney. We evaluated the renal hemodynamic status of 19 hypertensive patients with NIDDM under controlled sodium balance, low (10 mmol/day for 5 to 7 days) or high (200 mmol/day for 5 to 7 days). The renal plasma flow (RPF) response to ACE inhibition and to angiotensin II (Ang II) infusion was measured as para-aminohippurate (PAH) clearance before and during enalapril administration (10 mg b.i.d. for 3 days). Our premise was that if renal vasodilation induced by ACEI involves kinins, prostaglandins, and/or nitric oxide, vasoconstrictor responses to Ang II would be blunted. Conversely, if the dominant ACE inhibitor action were a reduction in Ang II formation, the consequence would be up-regulation and an enhanced vasoconstrictor response to exogenous Ang II. RPF in NIDDM on a high-salt diet was lower than in age-matched controls (477 +/- 25 vs. 551 +/- 25 ml/min/1.73 m2; P = 0.02). Enalapril increased RPF in NIDDM to 511 +/- 29 ml/min/1.73 m2 (P < 0.05) and enhanced renal vasoconstrictor responses to Ang II infusion, from -68 +/- 9 to -106 +/- 18 ml/min/1.73 m2 (P = 0.03). Baseline plasma renin activity (PRA) and plasma aldosterone significantly exceeded matched normotensive controls (1.1 +/- 0.5 vs. 0.3 +/- 0.1 ng AI/ml/hr and 10 +/- 0.9 vs. 4.1 +/- 0.5 ng/dl, P < 0.01, respectively). Conversely all measures in studies on a low-salt diet were normal. Our findings indicate that: (1) NIDDM with hypertension is associated with reduced RPF when dietary salt intake is high, (2) reduced Ang II formation is the dominant mechanism of ACEI-induced renal vasodilation in hypertensives with NIDDM; and (3) the sustained renal hemodynamic responses to ACE inhibition despite high-salt balance, and the increased PRA suggest an autonomous renin-angiotensin system suppressed subnormally by a high salt diet in patients with NIDDM despite greater volume expansion.

Lisinopril. A review of its pharmacology and use in the management of the complications of diabetes mellitus

Lisinopril, like other ACE inhibitors, lowers blood pressure and preserves renal function in hypertensive patients with non-insulin-dependent or insulin-dependent diabetes mellitus (NIDDM or IDDM) and early or overt nephropathy, without adversely affecting glycaemic control or lipid profiles. On available evidence, renoprotective effects appear to be greater with lisinopril than with comparator calcium channel blockers, diuretics and beta-blockers, despite similar antihypertensive efficacy. As shown by the EUCLID (EUrodiab Controlled trial of Lisinopril in Insulin-Dependent Diabetes) trial, lisinopril is also renoprotective in normotensive patients with IDDM and microalbuminuria. The effect in normotensive patients with normoalbuminuria was smaller than in those with microalbuminuria, and no conclusions can yet be made about its use in patients with normoalbuminuria. In complications other than nephropathy, lisinopril has shown some benefit. Progression to retinopathy was slowed during 2 years' lisinopril therapy in the EUCLID study. Although not yet fully published, these results provide the most convincing evidence to date for an effect of an ACE inhibitor in retinopathy. The drug may also improve neurological function, but this finding is preliminary. Lastly, post hoc analysis of the GISSI-3 trial indicates that lisinopril reduces 6-week mortality rates in diabetic patients when begun as early treatment after an acute myocardial infarction. The tolerability profile of lisinopril is typical of ACE inhibitors and appears to be similar in diabetic and nondiabetic individuals. Hypoglycaemia has occurred at a similar frequency with lisinopril and placebo, as shown in the EUCLID trial. In addition, the GISSI-3 study indicates that the incidence of persistent hypotension and renal dysfunction is increased with lisinopril in general, but the presence of diabetes does not appear to confer additional risk of these events in diabetic patients with acute myocardial infarction receiving lisinopril. In summary, lisinopril lowers blood pressure and produces a renoprotective effect in patients with IDDM and NIDDM without detriment to glycaemic control or lipid profiles. Like other ACE inhibitors, lisinopril should thus be viewed as a first-line agent for reducing blood pressure and preventing or attenuating nephropathy in hypertensive diabetic patients with IDDM or NIDDM and microalbuminuria or overt renal disease. The EUCLID study, using lisinopril, provides new data supporting an additional place in managing normotensive patients with microalbuminuria and IDDM. These findings, together with some evidence for an effect of lisinopril in delaying progression of retinopathy and in reducing mortality, suggest a broader role for the drug in managing diabetic vascular complications.

Day-night blood pressure variation in normotensive and hypertensive NIDDM patients with asymptomatic autonomic neuropathy

In order to assess the characteristics of day-night blood pressure (BP) variation in normotensive and hypertensive non-insulin-dependent diabetic (NIDDM) patients with asymptomatic autonomic neuropathy, 54 NIDDM patients and 13 healthy control subjects were studied by casual BP measurements and 24-h ambulatory blood pressure monitoring. Signs but not symptoms of autonomic neuropathy were documented by results of standard cardiovascular function tests in each patient. Daytime (06:00-22:00) and nighttime (22:00-06:00) BP values were separately analyzed and delta day-night BP values and diurnal index were determined. Patients were classified as being normotensive or having hypertension according to the casual BP values and medical history. In normotensive NIDDM patients (n = 30), nighttime systolic BP was significantly higher, whereas delta day-night systolic and delta day night diastolic BP values as well as diurnal index were considerably lower than those in control subjects (n = 13). In hypertensive NIDDM patients (n = 24), similar alterations were found at higher BP levels. No significant difference was found in BP values if normoalbuminuric and microalbuminuric NIDDM patients were compared. 'Non-dipper' phenomenon could be found in normotensive and hypertensive NIDDM patients with asymptomatic autonomic neuropathy, suggesting that relative sympathetic overdrive due to incipient and predominantly parasympathetic impairment of cardiovascular innervation might play a role in early alterations of circadian BP variation.

Adverse effects of the angiotensin-converting enzyme inhibitors

OBJECTIVE

To review current literature relating to the adverse effects of the angiotensin-converting enzyme (ACE) inhibitors.

DATA SOURCES

Online drug information sources, including MEDLINE (1966-November 1994), Iowa Drug Information Service, and the Australian Medical Index (AMI), were used to identify relevant literature, including reviews.

DATA EXTRACTION

Data were extracted from studies described in the English-language literature dealing with the adverse effects of ACE inhibitors. Comprehensive reviews and relevant case reports also were included.

DATA SYNTHESIS

Important adverse effects of ACE inhibitors include first-dose hypotension, renal dysfunction, hyperkalemia, and cough. Less common adverse effects include angioedema, hepatotoxicity. Skin rashes, and dysgeusia. ACE inhibitors also are associated with adverse fetal effects; thus, this class of drugs in contraindicated in pregnancy. Some adverse effects of ACE inhibitors are predictable on the basis of the fundamental pharmacology of this class of drugs. However, other effects are idiosyncratic in nature, although these reactions are generally much less common.

CONCLUSIONS

Attention to the principles of risk assessment, risk immunization, and patient monitoring are important when ACE inhibitor therapy is used for any indication. Provided these steps are taken. ACE inhibitors are generally a safe and effective class of drugs.

Natural history of early diabetic nephropathy: what are the effects of therapeutic intervention? Melbourne Diabetic Nephropathy Study Group

Several studies have shown that lowering of blood pressure slows the rate of progression of diabetic renal disease. Some placebo-controlled studies have also shown that angiotensin-converting enzyme (ACE) inhibitors decrease or stabilize albuminuria in incipient nephropathy and slow the rate of progression of advanced nephropathy. However, it is not yet clear if prolonged treatment with ACE inhibitors or with other agents exerts a specific renoprotective effect in incipient diabetic nephropathy. It is proposed that such an effect should be independent from changes in systemic blood pressure and should be characterized by amelioration of the rate of rise of albumin excretion rate (AER) and the rate of fall of glomerular filtration rate (GFR) and independence from changes in other parameters known to influence AER (glycemic control, protein intake, sodium intake). In addition, there should be evidence that the potentially reversible effects of therapeutic intervention on AER and GFR are translated to long-term changes in renal function and structure. This paper reviews the evidence on which the concept of renoprotection is based, with particular reference to choice of end points, heterogeneity of study groups, and complexities of the disease process, and relates this evidence to the natural history of nephropathy in type I and type II diabetes. Based on the above, an assessment is made of the comparative effects of ACE inhibitors and other antihypertensive agents on AER and GFR. It is suggested that longitudinal intra-individual analysis of both variables may be necessary in order to determine whether ACE inhibitors exert greater renoprotection than calcium channel blockers or other antihypertensive agents.

Diabetic renal disease: the quest for normotension--and beyond

Over the past two decades there has been an increasing interest in hypertension as a risk factor for diabetic renal disease and in particular for the possibility of early antihypertensive intervention. Therefore, it would seem timely to review the history of hypertension in diabetes, with special reference to renal disease and the need for normotension, in a manner resembling glycaemic control. Elevated blood pressure (BP) associated with diabetes mellitus has been recognized since the beginning of the century and was initially particularly documented in association with the demonstration of the striking histological lesion in glomeruli, starting with the observation of Kimmelstiel and Wilson in 1936. These patients in many cases also showed hypertension, as confirmed in several subsequent reports, very similar to the studies of Kimmelstiel and Wilson. However, the development was hampered by the lack of effective antihypertensive agents and also by some who believed that elevated BP could be of importance to preserve renal function in these individuals. Indeed, it was suggested that reduction of BP could mean permanent deterioration in renal function. BP remained very high in the standard care of diabetic patients up to the middle 1970s. At this time it was documented that elevated BP was very closely related to development of diabetic renal disease in Type 1 (insulin-dependent) diabetic (IDDM) patients, and studies also showed a correlation between blood pressure and rate of progression. This correlation stimulated research in intervention, and indeed in the 1980s and 1990s several long-term studies reported that antihypertensive treatment can reduce the rate of decline in glomerular filtration rate (GFR) from about 12 ml min-1 yr-1 down to about 2 ml min-1 yr-1 in the most optimistic reports; usually a mean level of 2-5 ml min-1 yr-1 is achievable by antihypertensive treatment, in clinical situations where glycaemic control often is far from perfect. Many studies have also documented that BP starts to rise in the early phase of incipient diabetic nephropathy characterized by microalbuminuria. This is a stage with well-preserved GFR and therefore probably an ideal stage for intervention in these at risk patients. Many studies, in particular those employing angiotensin converting enzyme (ACE) inhibitors based on important pathophysiological concepts proposed by Brenner, have shown that microalbuminuria can be reduced or stabilized by early antihypertensive treatment, just as we see with optimized glycaemic control. ACE inhibitors have also been widely used in patients with overt nephropathy and the rate of decline in GFR has been reduced considerably.(ABSTRACT TRUNCATED AT 400 WORDS)

Management of early nephropathy in diabetic patients

Diabetic patients go through several stages of renal disease, moving from normo- to micro- to macroalbuminuria. Good metabolic control can prevent or postpone the development of microalbuminuria, the earliest sign of diabetic renal disease. Thus, efforts should focus on obtaining the best possible control before the onset of microalbuninuria. In patients with microalbuminuria, blood pressure starts to increase, and early antihypertensive treatment becomes important. Good glycemic control may be difficult to achieve. With overt nephropathy, defined as clinical proteinuria, a relentless decline in glomerular filtration rate (GFR) occurs unless patients are carefully treated with antihypertensive agents. Protein restriction may also be necessary, but a clear beneficial effect of optimized diabetes care is difficult to document. Early screening is recommended, with an emphasis on testing for albuminuria, including microalbuminuria, along with careful control of blood pressure.