Hypoglycaemia associated with use of inhibitors of angiotensin converting enzyme

Frequent non-cardiac comorbidities in patients with chronic heart failure

Heart failure (HF) in elderly patients is associated with more diffuse symptoms and signs due to the presence of other noncardiac comorbidities. This can cause difficulties in assessing the correct diagnosis and initiating appropriate therapy. The four most frequently occurring noncardiac comorbidities and therapies used to treat them are discussed in the present paper. Hypertension is an important precursor of HF, and is still the most common risk factor for HF in the general population. About 50% of patients with untreated hypertension will develop HF. Pressure overload leads to the development of left ventricular hypertrophy (LVH) and diastolic dysfunction. Diabetes, which occurs in about 20-30% of patients with HF, is an important comorbidity resulting in morphological and metabolic disturbances affecting myocardial blood flow and hormonal regulation leading to a poor outcome and necessitating aggressive conventional treatment. Chronic obstructive pulmonary disease (COPD), occurs in approximately 20-30% of heart failure patients, and may complicate HF treatment, it is therefore important to recognize and treat it effectively. Finally, the early detection of anemia, which occurs in 20-30% of HF patients, is important since it is associated with functional impairment and increased mortality and morbidity. Combined treatment with erythropoietin and intravenous iron has shown beneficial effects on clinical symptoms and morbidity. In conclusion early detection of concomitant diseases in patients with HF is important and should be considered carefully when initiating therapy.

Suppressor of cytokine signaling-3 Provides a novel interface in the cross-talk between angiotensin II and insulin signaling systems

Angiotensin II inhibits insulin-induced activation of phosphatidylinositol 3-kinase through a mechanism, at least in part, dependent on serine phosphorylation of the insulin receptor and insulin receptor substrates (IRS)-1/2. Recent evidence shows that suppressor of cytokine signaling-3 (SOCS-3) is induced by insulin and angiotensin II and participates in the negative control of further stimulation of each of these signaling systems independently. In the present study, we evaluated the interaction of angiotensin II-induced SOCS-3 with the insulin signaling pathway in the heart of living rats. A single iv dose of angiotensin II promotes a significant increase of SOCS-3 in heart, an effect that lasts up to 180 min. Once induced, SOCS-3 interacts with the insulin receptor, JAK-2, IRS-1, and IRS-2. The inhibition of SOCS-3 expression by a phosphorthioate-modified antisense oligonucleotide partially restores angiotensin II-induced inhibition of insulin-induced insulin receptor, IRS-1 and IRS-2 tyrosine phosphorylation, and IRS-1 and IRS-2 association with p85-phosphatidylinositol 3-kinase and [Ser473] phosphorylation of Akt. Moreover, the inhibition of SOCS-3 expression partially reverses angiotensin II-induced inhibition of insulin-stimulated glucose transporter-4 translocation to the cell membrane. These results are reproduced in isolated cardiomyocytes. Thus, SOCS-3 participates, as a late event, in the negative cross-talk between angiotensin II and insulin, producing an inhibitory effect on insulin-induced glucose transporter-4 translocation.

Severe hypoglycaemia in 1076 adult patients with type 1 diabetes: influence of risk markers and selection

BACKGROUND

Differences between studies in rates of severe hypoglycaemia in type 1 diabetic cohorts are common and poorly understood. The purpose of this study was to assess the frequency of severe hypoglycaemia in unselected patients treated in different secondary care centres and to evaluate the influence of risk markers, clinical setting and selection.

METHODS

Cross-sectional Danish-British multicentre survey of 1076 consecutive adult patients with clinical type 1 diabetes who completed a detailed questionnaire on hypoglycaemia and related issues. Key variable was the self-reported rate of severe hypoglycaemia during the preceding year.

RESULTS

The overall rate of severe hypoglycaemia in the preceding year was 1.3 episodes/patient-year and episodes were reported by 36.7% of subjects. The distribution was highly skewed with 5% of subjects accounting for 54% of all episodes. There were no significant differences between countries or centres. Reduced hypoglycaemia awareness, peripheral neuropathy and smoking were the only significant risk markers of severe hypoglycaemia in a stepwise multivariate analysis. In a subgroup selected to be similar to the Diabetes Control and Complications Trial (DCCT) cohort, the rate of severe hypoglycaemia was 0.35 episodes/patient-year and only retinopathy was a significant risk marker together with state of awareness.

CONCLUSION

Severe hypoglycaemia remains a significant clinical problem in type 1 diabetes. The rate of severe hypoglycaemia and the influence of risk markers are very sensitive to selection and differences in rates between centres or studies seem to disappear after correction for differences in clinical characteristics. Smoking is a novel overall risk marker of severe hypoglycaemia.

A Systematic Approach to Managing Hypertension and the Metabolic Syndrome in Primary Care

OBJECTIVES

Obesity is driving a high prevalence of hypertension and metabolic syndrome-related risk and disease. This report summarizes the impact of a standardized, evidence-based approach to managing high blood pressure and associated metabolic syndrome abnormalities that was developed and implemented by one Clinical Hypertension Specialist.

METHODS

Longitudinal data on blood pressure, low-density lipoprotein cholesterol (LDL-C), hemoglobin A1c (HbA1c), cardiovascular and renal comorbidities, and treatment medications were obtained on all 817 hypertensive patients seen from January 1, 2000 to June 30, 2003.

RESULTS

The hypertensive patients were 72 +/- 11 (SD) years old, and more than 55% of them were high risk based on target organ damage, clinical cardiovascular disease, or diabetes mellitus. Blood pressure was < 140/90 mm Hg in 77% of all patients. Among the high-risk patients, mean blood pressure was 126 +/- 14/71 +/- 10 on 2.8 +/- 1.4 antihypertensive medications, with 88% on angiotensin converting enzyme inhibitors or angiotensin receptor blockers, 59% on diuretics, 49% on calcium channel blockers, and 36% on beta-blockers. Among dyslipidemic hypertensives, LDL-C was controlled to < 130 mg/dL in 84% (510/605) overall and to < 100 mg/dL in 70% of the high-risk group (299/427). Among diabetic hypertensives, the mean HbA1c was 6.8%, with 64% (155/242) less than 7%. New patients demonstrated improved blood pressure, LDL-C, and hemoglobin A1c control over time as the management algorithm was applied.

CONCLUSIONS

A high prevalence of complicated hypertension was documented. Blood pressure, LDL-C, and HbA1c were controlled to goal in a high proportion of patients. The findings demonstrate that application of an evidence-based management algorithm can facilitate higher rates of cardiovascular risk factor control than are generally reported in primary care practices.

The CORE Diabetes Model: Projecting long-term clinical outcomes, costs and cost-effectiveness of interventions in diabetes mellitus (types 1 and 2) to support clinical and reimbursement decision-making

OBJECTIVES

We have developed an Internet-based, interactive computer model to determine the long-term health outcomes and economic consequences of implementing different treatment policies or interventions in type 1 and type 2 diabetes mellitus. The model projects outcomes for populations, taking into account baseline cohort characteristics and past history of complications, current and future diabetes management and concomitant medications, screening strategies and changes in physiological parameters over time. The development of complications, life expectancy, quality-adjusted life expectancy and total costs within populations can be calculated.

METHODS

The model is based on a series of sub-models that simulate important complications of diabetes (cardiovascular disease, eye disease, hypoglycaemia, nephropathy, neuropathy, foot ulcer, amputation, stroke, ketoacidosis, lactic acidosis and mortality). Each sub-model is a Markov model using Monte Carlo simulation incorporating time, state, time-in state, and diabetes type-dependent probabilities derived from published sources. Analyses can be performed on cohorts with type 1 or type 2 diabetes. Cohorts, defined in terms of age, gender, baseline risk factors and pre-existing complications, can be modified or new cohorts defined by the user. Economic and clinical data in the model can be edited, thus ensuring adaptability by allowing the inclusion of new data as they become available; creation of country- or provider-specific versions of the model; and allowing the investigation of new hypotheses.

CONCLUSIONS

The CORE Diabetes Model allows the calculation of long-term outcomes, based on the best data currently available. Diabetes management strategies can be compared in different patient populations in a variety of realistic clinical settings, allowing the identification of efficient diabetes management strategies.

Initiation of glucose-lowering therapy in Type 2 diabetes mellitus patients in general practice

AIM

The purpose of this study was to investigate which factors determine the initiation of glucose-lowering therapy in patients with Type 2 diabetes mellitus in general practice and their future glycaemic control.

METHODS

All incident Type 2 diabetic patients in the general practices in a Dutch middle-sized town from 1994 to 2000 were identified. Factors associated with initiation of glucose-lowering therapy were obtained from clinical files and examined by Cox's regression analyses. Using anova, the associations between clinical characteristics at diagnosis and future glycaemic control were investigated.

RESULTS

In total, 603 newly diagnosed patients with Type 2 diabetes mellitus were included in the study. In the first month following diagnosis, 319 (53%) started with oral therapy. One, two and three years after diagnosis of diabetes, the cumulative incidences were 71% (95% CI 66-73%), 75% (71-79%) and 81% (77-84%), respectively. Age, gender, body weight, blood pressure, history of cardiovascular disease or total serum cholesterol values were not associated with time to start of drug therapy. An increased plasma glucose level at diagnosis was strongly related to faster initiation of drug therapy and worse future glycaemic control. Immediate initiation of glucose-lowering medication was not related to future glycaemic control.

CONCLUSION

This study shows that the initial severity of diabetes, assessed by the degree of hyperglycaemia at time of diagnosis, is a major factor in determining the time to start of glucose-lowering drugs and the likelihood of achieving target levels of glycaemic control in the future, independent of glucose-lowering strategy. Therefore, patients with high glucose levels at diagnosis need close monitoring from the beginning of their disease.

Antihypertensive drugs: an overview

For most patients with systemic hypertension, long-term drug treatment is indicated and is beneficial. There is overwhelming evidence to suggest that antihypertensive drugs offer protection against complications of hypertension. Whereas nondrug therapeutic options should be implemented in all patients, a vast majority will require pharmacological treatment to achieve goal blood pressure levels. Fortunately, a number of drugs are available to accomplish successful treatment of hypertensive disorders. While it is conventional to initiate treatment with a single drug, a suitable combination of drugs is often required to control the blood pressure effectively. Although diuretics and beta-blockers are effective and well tolerated, other classes of drugs are being increasingly used as the initial choice of therapy for hypertension. Every class of antihypertensive drugs offer advantages and some disadvantage; the physician should weigh the benefits and risks in selecting one drug over another. While the clinical parameters are followed in the management of patients with hypertension, it is also necessary to monitor the patients' biochemical profile periodically in order to modify and adjust the therapy accordingly. A careful selection of drug therapy along with close follow-up offers the best prospect to reduce the burden of morbidity and mortality in hypertension. This article provides an overview of drugs in the management of patients with hypertension.

Cost-effective strategies in the prevention of diabetic nephropathy

A significant subgroup of patients with diabetes mellitus are predisposed to developing diabetic nephropathy and it is in this subgroup that other diabetes- related complications, and in particular greatly increased cardiovascular disease risk, are concentrated. The high personal, social and financial costs of managing end-stage renal failure and the other complications associated with diabetic nephropathy make a powerful case for screening and effective intervention programmes to prevent the condition or retard its progression. As major breakthroughs in finding genetic susceptibility factors remain elusive, screening efforts continue to be based on microalbuminuria testing, despite increasing recognition of its limitations as a positive predictor of nephropathy. Interventions have been extensively studied, but results remain conflicting. Economic evaluations of such screening and intervention programmes are essential for health planners, yet models of the cost/benefit ratio of such interventions often rely on a rather slim evidence base. Where economic models are developed, they are frequently based on those papers that propound the greatest clinical benefits of a given intervention, leading to a possible over-estimation of the advantages of the chosen approach. Furthermore, the benefits of even such generally accepted interventions as ACE inhibitor treatment are less firmly established than generally appreciated. Lifestyle interventions are instinctively attractive, but are by no means a low-cost option (as is often assumed by both medical professionals and politicians). This review critically assesses the evidence for clinical efficacy and economic benefit of microalbuminuria screening and interventions such as intensive glycaemic control, antihypertensive treatment, ACE inhibition and angiotensin receptor blockade, dietary protein restriction and lipid-modifying therapy. The various costs associated with diabetic nephropathy are so great that even expensive interventions may have a favourable cost/benefit ratio, provided they are truly effective.

Hypoglycaemia in Elderly Patients with Diabetes Mellitus

Achieving target glycaemic goals while avoiding hypoglycaemia is a major challenge in the management of elderly patients with diabetes mellitus. Repeated episodes of hypoglycaemia may cause extreme emotional distress in such patients, even when the episodes are relatively mild. Moreover, evidence is mounting that hypoglycaemia among elderly patients is a very real and costly health concern. The strongest predictors of severe hypoglycaemia in the elderly are advanced age, recent hospitalisation and polypharmacy. Education is the key to preventing recurrent or severe hypoglycaemia. As such, there should be close coordination of care between the patient, physician and all other healthcare providers in identifying the cause of hypoglycaemia in elderly patients, and appropriate steps should be taken to prevent further episodes. Prevention of hypoglycaemia has the potential to improve psychosocial aspects of elderly health, including enhanced quality of life, boosted confidence, improved compliance with antidiabetic regimens and avoidance of long-term complications. Since the elderly population represents a unique group, it is imperative to focus on the aetiologies that are exclusive to this group. Advanced age itself is a risk factor for hypoglycaemia, and elderly patients with comorbidities are at increased risk when they are hospitalised. Elderly patients with diabetes often have compromised renal function, which intereferes with drug elimination and thus predisposes them to prolonged life-threatening hypoglycaemia. In addition, patients on five or more prescription medications are prone to drug-associated hypoglycaemia. Although sulfonylurea-associated hypoglycaemia is common, drugs such as ACE inhibitors and nonselective beta-adrenoceptor antagonists can also predispose patients to hypoglycaemia. Greater attention should be paid to the avoidance of hypgolycaemia in nursing home residents. Recurrent hypoglycaemia in elderly patients is not only detrimental to achieving good glycaemic control, it is also a substantial economic burden. Once the causes of hypoglycaemia have been identified, it is crucial to formulate and institute a prevention plan. Firstly, global evaluation of the patient should be carried out to identify possible predisposing risk factors. Secondly, target glycaemic goals should be tailored to each patient. Thirdly, selection of antidiabetic agents should be judicious, then patients and family should be educated to recognise and treat hypoglycaemia. Finally, coordinated care should be provided to identify, treat and prevent hypoglycaemia.

Differential effects of antihypertensive agents on electrocardiographic voltage: results from the Appropriate Blood Pressure Control in Diabetes (ABCD) trial

BACKGROUND

Serial decline in electrocardiographic voltage in patients with increased left ventricular mass has been associated with a lower risk of cardiovascular events.

METHODS

We studied 468 patients with diabetes mellitus and hypertension in the Appropriate Blood Pressure Control in Diabetes (ABCD) trial. Patients were randomized in a stratified design to receive initial treatment with either enalapril or nisoldipine and to either intensive or moderate treatment goals. We measured an electrocardiographic index for increased left ventricular mass, the adjusted Cornell voltage, serially by treatment group. The association between changes in electrocardiographic voltage and cardiovascular events was defined with Cox proportional hazards analysis.

RESULTS

In 5 years of follow-up, the decline in adjusted Cornell voltage was significantly greater for patients treated with enalapril than for patients treated with nisoldipine (repeated measures analysis of variance P =.002). In the Cox proportional hazards model, treatment assignment (enalapril vs nisoldipine) was the strongest predictor of cardiovascular events, but the presence of coronary disease at baseline, the duration of diabetes mellitus, and change in voltage were also independent predictors of cardiovascular events.

CONCLUSIONS

In the ABCD study, enalapril treatment was associated with a lower risk of myocardial infarction. The reduction in left ventricular mass as reflected by diminished electrocardiographic voltage may explain some, but not all, of the effect of enalapril in this study.

Drug treatment of benign prostatic hyperplasia and hospital admission for BPH-related surgery

OBJECTIVE

To investigate whether there is a difference in the risk of progressing to BPH-related prostatic surgery between patients using alpha-blockers and patients using the 5-alpha-reductase inhibitors (5-ARIs).

METHODS

A population-based cohort study was conducted, using data from the PHARMO Record Linkage System. We identified 5671 patients (> or =50 years old, no history of using both alpha-blockers and 5-ARIs, more than one year of database history prior to the first date of BPH drug-dispensing), who filled at least one prescription for either alpha-blockers (alfuzosin, tamsulosin, terazosin) or 5-ARIs (finasteride). The incidence of BPH-related surgery was compared between patients treated with alpha-blockers and patients treated with 5-ARIs.

RESULTS

The cumulative incidence of BPH-related prostatic surgery was 15.2% and mainly involved transurethral resection of the prostate (TURP) (13.4%). Patients using alpha-blockers had a significantly increased risk of BPH-related prostatic surgery compared to patients using 5-ARIs, which remained after adjusting for age, calendar time, type of prescriber and chronic disease score (adjusted HR: 1.52, 95% CI: 1.24-1.88). The difference between alpha-blockers and 5-ARIs was sustained after stratification of time period (<1995, > or =1995) and exclusion of patients with prostatic surgery within one month of treatment initiation.

CONCLUSIONS

It is concluded that alpha-blocker treated patients had a higher risk of BPH-related surgery compared to 5-ARI treated patients. Additional research on the long-term outcomes and risk factors for the natural progression of BPH is necessary to identify the optimal medical treatment for BPH patients according to their baseline characteristics.

The use of inhaled corticosteroids in the United Kingdom and the Netherlands

This study examined the utilisation patterns of inhaled corticosteroids in England/Wales and the Netherlands. Computerised medical records from the GPRD (U.K.) and PHARMO (the Netherlands) databases were used. It included 284733 English/Welsh and 27761 Dutch adult patients who were prescribed inhaled corticosteroids during the 10-year study period. Our results showed that, in both study populations, overall use of inhaled corticosteroids increased over the period studied, with its prevalence rising steeply with age and declining in extreme old age. Decreased use of bronchodilators and oral corticosteroids in the early treatment of asthma was noted in our findings. In addition, a trend towards the decreasing use of oral corticosteroids concomitant with inhaled corticosteroid therapy was also observed for both groups. Our study found that only 42.1% of the GPRD and 31.1% of the PHARMO patients received a repeat prescription within the expected duration ofthe preceding inhaled corticosteroid prescription. In conclusion, our study found many similarities in the prescribing and use of inhaled corticosteroids between the two study populations. The observation of irregular use of inhaled corticosteroid among a substantial number of patients highlights a need for further study into the reasons for irregular use and its consequences on the effectiveness of treatment.

Analysis of metabolic parameters as predictors of risk in the RENAAL study

OBJECTIVE

Metabolic factors such as glycemic control, hyperlipidemia, and hyperkalemia are important considerations in the treatment of patients with type 2 diabetes and nephropathy. In the RENAAL (Reduction of End Points in Type 2 Diabetes With the Angiotensin II Antagonist Losartan) study, losartan reduced renal outcomes in the patient population. This post hoc analysis of the RENAAL study reports the effects of losartan on selected metabolic parameters and assesses the relationship between baseline values of metabolic parameters and the primary composite end point or end-stage renal disease (ESRD).

RESEARCH DESIGN AND METHODS

Glycemic control (HbA(1c)) and serum lipid, uric acid, and potassium levels were compared between the losartan and placebo groups over time, and baseline levels were correlated with the risk of reaching the primary composite end point (doubling of serum creatinine, ESRD, or death) or ESRD alone.

RESULTS

Losartan did not adversely affect glycemic control or serum lipid levels. Losartan-treated patients had lower total (227.4 vs. 195.4 mg/dl) and LDL (142.2 vs. 111.7 mg/dl) cholesterol. Losartan was associated with a mean increase of up to 0.3 mEq/l in serum potassium levels; however, the rate of hyperkalemia-related discontinuation was similar between the placebo and losartan groups. Univariate analysis revealed that baseline total and LDL cholesterol and triglyceride levels were associated with increased risk of developing the primary composite end point. Similarly, total and LDL cholesterol were also associated with increased risk of developing ESRD.

CONCLUSIONS

Overall, losartan was well tolerated by patients with type 2 diabetes and nephropathy and was associated with a favorable effect on the metabolic profile of this population.

Influence of captopril on symptomatic and hormonal responses to hypoglycaemia in humans

AIMS

Hypoglycaemic symptoms and hormonal counter-regulation are of high importance to avoid the risk of severe hypoglycaemia in patients with diabetes mellitus. Various antihypertensive drugs, such as angiotensin-converting enzyme (ACE) inhibitors, have been suspected for a long time to reduce this response to hypoglycaemia in diabetic subjects. Although ACE inhibitors are approved for controlling diabetic complications, previous investigations regarding this putative side-effect are controversial.

METHODS

We performed clamp experiments in 16 healthy men lasting for 6 h each. The subjects were pretreated for 7 days with captopril 3 x 25 mg day-1 vs placebo in a randomized, double-blind, crossover study. Plasma glucose was decreased in a stepwise manner during a hypoglycaemic clamp session and counter-regulatory hormones [epinephrine (adrenaline), norepinephrine (adrenaline), ACTH, cortisol, glucagon], symptoms, and haemodynamic parameters (blood pressure, heart rate] were measured.

RESULTS

Counter-regulatory hormone concentrations significantly increased in both sessions (ACE inhibitor vs placebo) during hypoglycaemia. The rise of counter-regulatory hormones as well as symptom scores were equal under both ACE inhibitor and placebo treatment. Systolic blood pressure and heart rate increased (from 110 +/- 3 vs 115 +/- 3 mmHg to 132 +/- 4 vs 133 +/- 4 mmHg) whereas diastolic blood pressure slightly decreased (from 63 +/- 2 vs 70 +/- 3 mmHg to 61 +/- 2 vs 64 +/- 2 mmHg) independent of pretreatment. Systolic and diastolic blood pressure were significantly lower in the captopril session vs placebo (P < 0.05).

CONCLUSIONS

Our results demonstrate that subchronic treatment with captopril does not attenuate symptomatic and hormonal response to hypoglycaemia. Thus, to patients at risk of hypoglycaemia who require antihypertensive or nephroprotective treatment, we would continue giving an ACE inhibitor.

Pharmacological agents that directly modulate insulin secretion

Blood glucose levels are sensed and controlled by the release of hormones from the islets of Langerhans in the pancreas. The beta-cell, the insulin-secreting cell in the islet, can detect subtle increases in circulating glucose levels and a cascade of molecular events spanning the initial depolarization of the beta-cell membrane culminates in exocytosis and optimal insulin secretion. Here we review these processes in the context of pharmacological agents that have been shown to directly interact with any stage of insulin secretion. Drugs that modulate insulin secretion do so by opening the K(ATP) channels, by interacting with cell-surface receptors, by altering second-messenger responses, by disrupting the beta-cell cytoskeletal framework, by influencing the molecular reactions at the stages of transcription and translation of insulin, and/or by perturbing exocytosis of the insulin secretory vesicles. Drugs acting primarily at the K(ATP) channels are the sulfonylureas, the benzoic acid derivatives, the imidazolines, and the quinolines, which are channel openers, and finally diazoxide, which closes these channels. Methylxanthines also work at the cell membrane level by antagonizing the purinergic receptors and thus increase insulin secretion. Other drugs have effects at multiple levels, such as the calcineurin inhibitors and somatostatin. Some drugs used extensively in research, e.g., colchicine, which is used to study vesicular transport, have no effect at the pharmacological doses used in clinical practice. We also briefly discuss those drugs that have been shown to disrupt beta-cell function in a clinical setting but for which there is scant information on their mechanism of action.

Detection of adverse drug reactions in a neurological department: comparison between intensified surveillance and a computer-assisted approach

OBJECTIVES

Adverse drug reactions (ADRs) leading to hospitalisation or occurring during hospital stay contribute significantly to patient morbidity and mortality as well as representing an additional cost for healthcare systems. The aim of this study was to provide data about the type and incidence of ADRs in a neurological department and to compare two different methodological approaches to collecting information on ADRs.

METHODS

The two methods used were intensified surveillance of neurological wards by daily ward rounds and computer-assisted screening for ADRs by means of pathological laboratory parameters.

RESULTS

Of admissions to the neurological department, 2.7% were caused by an ADR and 18.7% of patients experienced at least one ADR during hospitalisation. The positive predictive values of pathological laboratory parameters ranged between 0% (eosinophil count) and 100% for increased drug serum concentrations and international normalised ratio, i.e. the latter were always accompanied by a clinically relevant ADR. However, only half of all ADR could be detected by pathological laboratory parameters, the sensitivity of this method came to 45.1% with a specificity of 78.9%.

CONCLUSION

Similar to departments of internal medicine, a high number of ADRs occur on neurological wards. The predominant ADRs were those typical of neurotropic medications such as dyskinesia and increased sedation. Due to the age of the patients involved, cardiovascular co-medication is often prescribed and represents an additional risk factor for ADRs. By measuring pathological laboratory parameters the majority of ADRs could not be detected in neurological patients.

The role of the angiotensin system in cardiac glucose homeostasis: therapeutic implications

Resistance to the metabolic actions of insulin is thought to play a determining role in the aetiology of a great variety of disorders, including essential hypertension, accelerated atherosclerosis and cardiomyopathies. ACE inhibitors are recognised as being highly effective therapy for hypertension and cardiac insufficiency, and have a more beneficial effect on survival rate than expected on the basis of known mechanisms of action. The mechanism responsible for these extremely positive effects are just beginning to be understood and appear to be linked to the effects these drugs have on metabolism. The relationship between the insulin and angiotensin II (Ang II) signalling pathways needs to be fully clarified in order to prevent or correct the target organ damage resulting from changes in the cross-talk of these two hormonal systems. In recent years, Ang II has been shown to play a central role in cardiovascular and neuroendocrine physiology as well as in cellular cycle control. Moreover, the fact that Ang II utilises the insulin-receptor substrate (IRS)-1 to relay signals towards their intracellular destination, provides the biochemical explanation of how these two systems interact in a healthy organism and in a diseased one. Since it is overactivity of the renin-angiotensin system that seems to impair the intracellular response to insulin signalling, cardiovascular drugs that modulate the cellular transmission of Ang II have attracted particular interest. As well as the already widely-used ACE inhibitors, selective blockers of the Ang II type 1 receptor (AT(1)) have been shown to be clinically effective in the control of haemodynamic parameters, but with perhaps a less striking effect on glucose homeostasis. Many trials have investigated the effect of Ang II blockade on systemic glucose homeostasis. The inhibition of Ang II by ACE-inhibitors frequently showed a positive effect on glycaemia and insulin sensitivity, while information on the effects of AT(1) receptor antagonists on glucose homeostasis is more limited and controversial. An important limitation of these studies has been the short treatment and follow-up periods, even for the 'so called' long-term studies which were only 6 months. Several investigators have focused on the effects of the nuclear factors involved in gene transcriptions, especially with respect to the agonists/antagonists of peroxisome proliferator-activated receptors (PPARs) and their intriguing interconnections with the insulin and Ang II subcellular pathways. In fact, in vitro and in vivo experimental studies have shown that thiazolidinediones (selective PPAR-gamma ligands) are not only powerful insulin sensitisers, but also have anti-hypertensive and anti-atherosclerotic properties. In addition to conventional pharmacological approaches, attempts have been made to use genetic transfer in the treatment of cardiovascular and metabolic disorders. The development of powerful viral vectors carrying target genes has allowed us to restore the expression/function of specific proteins involved in the cellular mechanism of insulin resistance, and research now needs to move beyond animal models. Although a clearer picture is now emerging of the pathophysiological interaction between insulin and Ang II, especially from pre-clinical studies, there is much to be done before experimental findings can be used in daily clinical practice.

Role of ACE inhibitors in treating hypertensive diabetic patients

Cardiovascular disease (CVD) is a major determining factor of morbidity and mortality in type 2 diabetic patients. Hypertension, which accompanies diabetes in more than 70% of cases, contributes to increased prevalence of CVD events in this group of patients. Results from the United Kingdom Prospective Diabetes Study (UKPDS) indicated that reduction of elevated blood pressure might decrease CVD morbidity and mortality more than reduction of hyperglycemia. Activation of circulating and tissue renin-angiotensin system (RAS) contributes to the development of both hypertension and insulin resistance in patients with the cardiometabolic syndrome. Angiotensin-converting enzyme (ACE) inhibitor therapy in patients with the cardiometabolic syndrome may improve insulin action as well as lessen CVD. In clinical trials, ACE inhibitors have been shown to be more efficient than other antihypertensive medications (i.e., calcium channel blockers) in the reduction of CVD morbidity and mortality in hypertensive diabetics. In this article, we summarize possible mechanisms by which ACE inhibition may improve insulin resistance, coagulation/clotting, and vascular function abnormalities, and postpone or even prevent the development of type 2 diabetes in hypertensive patients.

Clinical pharmacology of antihypertensive drugs

Systemic hypertension is a major public health problem and is perhaps the most common chronic disorder in most societies. Most patients with vascular disease report hypertension in their medical history. Irrespective of the specialty that one practices, every physician will likely encounter patients with systemic hypertension. Unfortunately, an overwhelming number have so-called "primary" or "essential" hypertension for which a cure has yet to be found. Fortunately, excellent therapy is available to control this modern malady. The field of hypertension continues to evolve rapidly, particularly in the field of therapy. During the past two decades, the treatment of hypertension has moved from a cookbook approach to more scientifically based individualized management. This paradigm shift requires the practitioner to acquire sufficient knowledge about individual drugs and how they work in a given patient. Rapid expansion of available drugs has placed a burden on the clinician to keep up with these advances. We hope that the discussions contained herein will ease that burden somewhat and make the treatment options less cumbersome. This article addresses the practical issues related to selection of antihypertensive drugs and provides an overview of advantages and disadvantages of individual drug classes. The reader should also refer to the JNC VI document [1] to further understand the selection of drug therapy based upon compelling indications. The ultimate aim of hypertension management should always be to achieve target or goal blood pressure levels.

Role of ACE inhibitors in patients with diabetes mellitus

The adjective 'epidemic' is now attributed to the rapidly growing number of patients with diabetes mellitus, mainly type 2. and the specific complications linked to this disorder. Provided they are recognised early enough, these different complications can be treated; in some patients the evolutive course of these complications can be slowed or even stopped. Furthermore, some recent observations suggest that specific tissular lesions may be prevented or even reversed. Although glycaemic control is essential, other therapeutic measures that must also be taken include those to control blood pressure and to lower lipid levels. Of the agents available to control the complications of diabetes mellitus, cardiovascular drugs, and particularly ACE inhibitors, have a pre-eminent place. Experimental and epidemiological data suggest that activation of the renin-angiotensin-aldosterone system plays an important role in increasing in the micro- and macrovascular complications in patients with diabetes mellitus. Not only are ACE inhibitors potent antihypertensive agents but there is a growing body of data indicating that also they have a specific 'organ-protective' effect. For the same degree of blood pressure control, compared with other antihypertensive agents, ACE inhibitors demonstrate function and tissue protection of considered organs. ACE inhibitors have been reported to improve kidney, heart, and to a lesser extent, eye and peripheral nerve function of patients with diabetes mellitus. These favourable effects are the result of inhibition of both haemodynamic and tissular effects of angiotensin II. Finally, there are a growing number of arguments favouring the use of ACE inhibitors very early in patients with diabetes mellitus.

The use of ACE inhibitors on diabetic patients without renal disease

Strategies that interrupt the renin-angiotensin system, especially with angiotensin-converting enzyme (ACE) inhibition, reduce cardiovascular disease mortality and morbidity in high-risk persons such as those with the insulin resistance syndrome and diabetes mellitus. In the 1980s emphasis was placed on the renal protective effects of ACE inhibitors in patients with diabetes and proteinuria. During the past several years controlled clinical trials have demonstrated that ACE inhibition reduces cardiovascular disease (CVD) mortality and morbidity. This is especially important in patients in the United States, where 80% of excess mortality for diabetes mellitus is attributed to CVD. This article reviews the clinical trials in high-risk patients, especially those with diabetes, that shown beneficial CVD risk reduction with ACE inhibitors.

Diabetic Cardiomyopathy

Diabetes mellitus is a major risk factor for the development of congestive heart failure (CHF). Diabetic cardiomyopathy has been acknowledged as a distinct disease entity that is an additional risk for diabetic patients to develop CHF, especially when they are affected by hypertension or epicardial coronary artery disease. Moreover, diabetic cardiomyopathy has been documented to lead to CHF even in the absence of other risk factors. As the combination of hypertension and diabetes has shown to be particularly detrimental, aggressive blood pressure control with a goal of less than 130/85 mm Hg is of critical importance. The first choice for pharmacologic treatment is angiotensin-converting enzyme inhibitors. Double- or triple-drug therapy is frequently required for good control. The increased risk of epicardial coronary artery disease in patients with diabetes warrants stringent treatment of dyslipidemia. If dilated cardiomyopathy with low ejection fraction is present, therapy with angiotensin-converting enzyme inhibitors, digoxin, diuretics, beta-blockers, and spironolactone (for patients with New York Heart Association class III to IV functional status) is indicated. If cardiac dysfunction consists predominantly of impaired diastolic function, heart rate control with a beta-blocker or a calcium antagonist is of particular importance. Control of blood glucose should be achieved, with hemoglobin A(1c) levels of less than 7%. Hyperinsulinemia should be avoided when possible; therefore, insulin-sensitizing agents are preferred over insulin-secretion-enhancing agents. Symptoms of CHF and acutely decompensated CHF should be treated no differently than nondiabetic patients. Care for patients with diabetes always includes lifestyle changes consisting of smoking cessation, decreasing obesity, regular exercise, and a heart-healthy diabetic diet.

Losartan modifies glomerular hyperfiltration and insulin sensitivity in type 1 diabetes

AIM

The effect of the angiotensin II receptor antagonist losartan on renal haemodynamics and insulin-mediated glucose disposal was examined in normotensive, normoalbuminuric type 1 diabetic patients using a double-blind, placebo-controlled, cross-over design.

METHODS

Diurnal blood pressure, glomerular filtration rate (GFR, determined using [125I]-iothalamate), renal plasma flow (RPF, determined using [131I]-hippuran) and urinary albumin excretion rate (UAE) were measured, and a hyperinsulinaemic, euglycaemic clamp with indirect calorimetry was performed in nine patients (age 30 +/- 7 years (mean +/- s.d.), HbA1c 8.1 +/- 1.1%) following 6 weeks' administration of either losartan 50 mg/day or placebo.

RESULTS

Diurnal blood pressure was significantly reduced after losartan compared with placebo (122/70 +/- 11/8 vs. 130/76 +/- 12/6 mmHg, p < 0.05). A significant decline in GFR (133 +/- 23 vs. 140 +/- 22 ml/min, p < 0.05) and filtration fraction (FF; GFR/RPF) (24.6 +/- 3.5 vs. 26.2 +/- 3.6%, p < 0.05) was observed in the losartan vs. placebo groups. RPF and UAE did not change. Isotopically determined glucose disposal rates were similar after losartan and placebo in the basal (2.61 +/- 0.53 vs. 2.98 +/- 0.93 mg/kg/min) and insulin-stimulated states (6.84 +/- 2.52 vs. 6.97 +/- 3.11 mg/kg/min). However, the glucose oxidation rate increased significantly after losartan vs. placebo in the basal state (1.72 +/- 0.34 vs. 1.33 +/- 0.18, mg/kg/min, p < 0.01) and during insulin stimulation (2.89 +/- 0.75 vs. 2.40 +/- 0.62 mg/kg/min, p < 0.03). Basal and insulin-stimulated non-oxidative glucose disposal tended to decrease after losartan; however, this was not significant. Endogenous glucose production and lipid oxidation were unchanged after treatment and similarly suppressed during hyperinsulinaemia. Glycaemic control, total cholesterol, high-density lipoprotein (HDL)-cholesterol and triglycerides were stable in both losartan and placebo groups.

CONCLUSIONS

Losartan reduces blood pressure, glomerular hyperfiltration and FF, and improves basal and insulin-stimulated glucose oxidation in normotensive, normoalbuminuric type 1 diabetic patients.

Risk of extrapyramidal syndromes with haloperidol, risperidone, or olanzapine

OBJECTIVE

To compare the risk of extrapyramidal syndrome (EPS) between risperidone, olanzapine, and haloperidol, taking into account patients' past antipsychotic drug use and past EPS.

METHODS

Data were obtained from the PHARMO-database, containing filled prescriptions of 450,000 community-dwelling people in the Netherlands from 1986 through 1999. We defined cohorts of first-time users of haloperidol, risperidone, or olanzapine aged 15 to 54 years. In the first 90 days of treatment, we assessed the occurrence of EPS, defined as first use of any antiparkinsonian agent. We estimated relative risks of EPS for risperidone and olanzapine versus haloperidol using a Cox proportional hazards model. Patients were subdivided according to prior use of antipsychotic and antiparkinsonian drugs.

RESULTS

We identified 424 patients starting treatment with haloperidol, 243 with risperidone, and 181 with olanzapine. Prior use of antipsychotic plus antiparkinsonian medication was significantly more frequent among users of risperidone and olanzapine than in those using haloperidol (36.2%, 40.3%, and 4.5%, respectively; p < 0.001). Within most subgroups of comparable treatment history, patients using risperidone and olanzapine showed reduced risks of EPS compared with haloperidol, although some of these findings did not reach statistical significance (RR 0.03-0.22). However, this was not observed for patients using risperidone who had experienced EPS in the past (RR 1.30; 95% CI 0.24 to 7.18).

CONCLUSIONS

In general, we observed reduced risks of EPS for risperidone and olanzapine compared with haloperidol within subgroups of patients with a similar treatment history. However, the added value of risperidone in patients who have experienced EPS in the past needs further study.

Betablocker treatment in diabetes mellitus

OBJECTIVES

Betablockers have been convincingly shown to reduce total and cardiovascular morbidity and mortality of hypertensive diabetic patients. In diabetic patients, after myocardial infarction, these agents confer a twice as high protective effect when compared to non-diabetic patients. However, most paradoxically, betablocking agents are used less frequently in diabetes. Control of hypertension is insufficient in most of the diabetic patients, probably because a combination of antihypertensive agents including betablockers is frequently needed to sufficiently control blood pressure but is not used in these patients. The fear of betablocker-associated side effects in diabetes may be partly responsible for the frequent antihypertensive mono-therapy and the resulting poor quality of blood pressure control among diabetic patients.

DESIGN

We have performed an analysis of the literature to assess whether possible adverse metabolic effects, a higher risk of hypoglycaemia or less nephroprotective effects of beta1-selective betablocking agents could justify the reticence in prescribing these antihypertensive agents to diabetic patients.

RESULTS

A thorough review of the literature does not indicate that beta1-selective betablocking agents have important adverse effects on glucose metabolism, prolong hypoglycaemia or mask hypoglycaemic symptoms. In diabetic nephropathy, betablockers are as nephroprotective as angiotensin converting enzyme inhibitors.

CONCLUSIONS

The unnecessary less frequent prescription of beta1-selective betablockers in diabetes mellitus may contribute to the higher cardiovascular mortality among these patients.

Diabetes mellitus and diabetes-associated vascular disease

Diabetes-related cardiovascular disease remains the leading cause of death in patients with type 2 diabetes. Hypertension is common among diabetics and has the same pathogenetic mechanisms as insulin resistance, in which the activated renin-angiotensin system contributes to the emerging high blood pressure and hyperglycemia. Hyperglycemia is one of the triggering factors for vascular dysfunction and clotting abnormalities and, therefore, for accelerated atherosclerosis in diabetes. Glycated hemoglobin levels, as a reflection of the degree of glycemia, are strongly associated with the risk of cardiovascular disease in diabetics and in the general population. Tight glycemic control, the treatment of dyslipidemia and raised blood pressure, in addition to the use of antiplatelet therapy, all powerfully reduce the risks associated with diabetes. Furthermore, angiotensin-converting enzyme inhibitors might offer additional cardioprotection to diabetics above that provided by blood pressure reduction.

Evaluating adverse cardiovascular effects of drug treatment for benign prostatic hyperplasia (BPH): methodological considerations

When studying the effects of drug exposure in diseases with a long asymptomatic clinical course, exposure classification may be biased by the gradually developing "visibility" of the disease. Benign prostatic hyperplasia (BPH) is such a disease. We found that cardiovascular morbidity is two times more prevalent in patients starting drug treatment for BPH when compared to age-matched population controls. This resulted in a difference of cardiovascular prognostic factors between the exposed and non-exposed. This feature can jeopardize the validity of non-randomized comparisons of drug effects. Moreover, the existence of non-treatment strategies, disease under-reporting, and an elderly population with a high baseline risk of experiencing (cardiovascular) outcome events were encountered as methodological problems. When studying adverse cardiovascular effects in patients using BPH products in a non-randomized fashion, an important question is whether we can measure in the database all relevant prognostic factors and use the information for statistical adjustment. This question is an important challenge to observational research and once again stresses the need for control of possible biases in choosing an appropriate study design.

Activity of angiotensin-converting enzyme and risk of severe hypoglycaemia in type 1 diabetes mellitus

BACKGROUND

The insertion (I) allele of the angiotensin-converting-enzyme (ACE) gene occurs at increased frequency in endurance athletes. This association suggests that low ACE activity is favourable for performance in conditions with limited substrate availability. Such conditions occur in endurance athletes during competition and in diabetic patients during insulin-induced hypoglycaemia. Patients rely on preserved functional capacity to recognise hypoglycaemic episodes and avoid progression by self-treatment. We studied whether ACE activity is related to the risk of severe hypoglycaemia in type 1 diabetes.

METHODS

Consecutive adult outpatients with type 1 diabetes, untreated with ACE inhibitors or angiotensin-II-receptor antagonists (n=207) reported their experience of mild and severe hypoglycaemia during the previous 1 year and 2 years. The patients were further characterised by diabetes history, degree of hypoglycaemia awareness, measurement of C-peptide, haemoglobin A(1c), and serum ACE concentrations, and determination of ACE genotype.

FINDINGS

Patients with the DD genotype had a relative risk of severe hypoglycaemia in the preceding 2 years of 3.2 (95% CI 1.4-7.4) compared with those who had the II genotype. There was a significant relation between serum ACE activity and the rate of severe hypoglycaemia (relative risk per 10 U/L increment 1.4 [1.2-1.6]), corresponding to a 3.5 times higher risk for patients in the highest quartile than for those in the lowest quartile. Multiple regression analysis showed that the effect of the ACE genotype was explained by its influence on serum ACE activity and that the only other significant determinants of the risk of severe hypoglycaemia were the degree of hypoglycaemia awareness, b-cell function, and duration of diabetes of more than 20 years.

INTERPRETATION

ACE activity is a clinically significant marker of the risk of severe hypoglycaemia in patients with type 1 diabetes, especially in those with impaired defence against hypoglycaemia. These findings need to be confirmed in prospective studies.

Brain angiotensin receptors and sympathoadrenal regulation during insulin-induced hypoglycemia

Simultaneous blockade of systemic AT1 and AT2 receptors or converting enzyme inhibition (CEI) attenuates the hypoglycemia-induced reflex increase of epinephrine (Epi). To examine the role of brain AT1 and AT2 receptors in the reflex regulation of Epi release, we measured catecholamines, hemodynamics, and renin during insulin-induced hypoglycemia in conscious rats pretreated intracerebroventricularly with losartan, PD-123319, losartan and PD-123319, or vehicle. Epi and norepinephrine (NE) increased 60-and 3-fold, respectively. However, the gain of the reflex increase in plasma Epi (Deltaplasma Epi/Deltaplasma glucose) and the overall Epi and NE responses were similar in all groups. The ensuing blood pressure response was similar between groups, but the corresponding bradycardia was augmented after PD-123319 (P < 0.05 vs. vehicle) or combined losartan and PD-123319 (P < 0.01 vs. vehicle). The findings indicate 1) brain angiotensin receptors are not essential for the reflex regulation of Epi release during hypoglycemia and 2) the gain of baroreceptor-mediated bradycardia is increased by blockade of brain AT2 receptors in this model.

Hypoglycemic syncope induced by a combination of cibenzoline and angiotensin converting enzyme inhibitor

A 65-year-old Japanese woman with dilated cardiomyopathy, hypothyroidism and refractory sustained ventricular tachycardia experienced a near-death hypoglycemic syncope. The attack seemed to be induced by a high level of serum insulin, probably due to cibenzoline and by concomitant use of an angiotensin converting enzyme inhibitor (ACEI). Additionally, decreased food intake because of a severe toothache may have contributed to the deterioration of her condition. This case warns cardiologists that a combined cibenzoline and ACEI therapy can provoke serious adverse effects such as hypoglycemic syncope in the elderly. Therefore, the possibility of a hypoglycemic attack associated with these drugs should be explained to patients who are in poor condition.

Effects of antihypertensive therapy on glucose and insulin metabolism and on left ventricular mass: A randomized, double-blind, controlled study of 21 obese hypertensives

BACKGROUND

Glucose and insulin levels are associated with left ventricular mass (LVM) in insulin-resistant individuals. Antihypertensive drugs have different effects on glucose and insulin metabolism (GIM) and on LVM. To evaluate whether the effects of antihypertensive therapy on LVM are associated with its effects on GIM, we compared the effects of atenolol and perindopril on these parameters in a group of insulin-resistant, obese hypertensives.

METHODS AND RESULTS

A total of 21 obese, nondiabetic hypertensives who were aged 55+/-12 years, had a body mass index of 32.8+/-5.0 kg/m(2), were free of coronary or valvular heart disease, and had normal LV function were randomized to treatment with atenolol (n=11) or perindopril (n=10). Echocardiographic LVM corrected for height (LVM/height) and GIM (3-hour intravenous glucose tolerance test) were measured after 4 to 6 weeks of washout and 6 months of treatment. Baseline characteristics were similar in both groups. Atenolol and perindopril effectively reduced blood pressure (from 149+/-13/98+/-4 to 127+/-8/82+/-6 mm Hg and from 148+/-9/98+/-4 to 129+/-9/82+/-6 mm Hg, respectively, for the atenolol and perindopril groups; P:=0.002). Atenolol significantly worsened GIM parameters, fasting glucose levels (5.3+/-0.9 to 6.0+/-1.5 mmol/L; P:=0.003), fasting insulin levels (121+/-121 to 189+/-228 pmol/L; P:=0.03), and most other relevant metabolic measures (P:<0.05 for all). Perindopril did not affect GIM. Atenolol did not affect LVM/height (119+/-12 to 120+/-17 g/m; P:=0.8), whereas perindopril significantly reduced LVM/height (120+/-13 to 111+/-19 g/m; P:=0.04).

CONCLUSIONS

In obese, hypertensive individuals, adequate and similar blood pressure control was achieved with perindopril and atenolol. However, perindopril but not atenolol was associated with a more favorable GIM profile and led to a significant regression of LVM.

Acute hemodynamic effects of insulin-sensitizing agents in isolated perfused rat hearts

Troglitazone has direct effects on the hemodynamics of the heart. We investigated the effects of other insulin-sensitizing agents (rosiglitazone, pioglitazone and JTT-501 (4-[4-[2-(5-methyl-2-phenyl-4-oxazolyl)ethoxy]benzyl]-3, 5-isoxazolidinedione)) on the hemodynamics of the heart using isolated perfused rat hearts. Rosiglitazone significantly decreased heart rate and coronary perfusion pressure, and increased peak isovolumic left ventricular pressure, peak rate of rise of left ventricular pressure and peak rate of fall of left ventricular pressure. The effects of rosiglitazone, however, were milder than those of troglitazone. Neither pioglitazone nor JTT-501 had any effect on the heart. D-alpha-tocopherol, a structural component of troglitazone, did not exert any effect on the heart. The coronary vasorelaxant effect of troglitazone and rosiglitazone was significantly suppressed by indomethacin, but not by N(omega)-nitro-L-arginine methyl ester. In conclusion, only rosiglitazone, as well as troglitazone, exerted positive inotropic, positive lusitropic, negative chronotropic, and coronary vasorelaxant effects on the heart. The coronary vasorelaxant effect of troglitazone and rosiglitazone was mediated by prostaglandin production.

Pharmacologic Regulation of the Renin—Angiotensin System: Physiologic and Pathologic Effects

Objective:

To review the physiologic and pathologic roles of the renin-angiotensin system in maintaining blood pressure, glomerular filtration rate, and myocardial tissue growth. The pharmacologic regulations of the pathologic effects of the renin-angiotensin system are emphasized, with a comparison between angiotensin-converting enzyme (ACE) inhibitors and angiotensin1receptor (AT1) antagonists.

Data Sources:

English-language basic science, clinical studies, and review articles were identified using MEDLINE, IOWA, and a manual search from January 1966 through September 1999. References were also obtained from the reference section of relevant published articles.

Study Selection and Data Extraction:

All articles identified were evaluated for possible inclusion in this review. Evaluative and comparative data from basic science and controlled clinical studies were reviewed.

Data Synthesis:

The renin-angiotensin system has a plethora of physiologic and pathologic roles in the regulation of blood pressure, renal function, and cell growth. The cellular mechanisms involved in eliciting the responses to the renin-angiotensin system are discussed in detail, with an emphasis on the pharmacologic regulation of the cellular responses. The role of angiotensin II in maintaining blood pressure, glomerular filtration rate, and in regulating myocardial cell growth secondary to myocardial infarction or as a complication of congestive heart failure are all reviewed. The ACE inhibitors and AT1antagonists have comparable pharmacologic effects that can influence their therapeutic application. The ACE inhibitors and AT, antagonists are compared regarding clinically and experimentally observed differences that may affect their therapeutic application.

Conclusions:

The physiologic and pathologic roles of the renin-angiotensin system make the ACE inhibitors and AT1antagonists ideal candidates in treating many conditions. Presently, few studies have been conducted that directly compare ACE inhibitors and AT, antagonists. An understanding of the basic underlying pharmacologic principles is essential when attempting to apply the scientific and clinical information of the ACE inhibitors and AT1antagonists with the intention of extrapolating to therapeutic utility.

Insulin sensitivity in hypertensive Type 2 diabetic patients after 1 and 19 days' treatment with trandolapril

AIMS

The aims of this study were to examine the effects of trandolapril, a long acting angiotensin converting enzyme (ACE) inhibitor with high tissue uptake, on insulin sensitivity and lipid concentrations in hypertensive patients with Type 2 diabetes mellitus.

METHODS

Insulin sensitivity was assessed after an acute dose (day 3) and 19 days continuous treatment (days 3-21) using the isoglycaemic, hyperinsulinaemic glucose clamp with D[3-3H] labelled glucose, a variable D[3-3H] priming dose and a 'hot' glucose infusion. Rates of glucose appearance (Ra) and glucose disappearance (Rd) were isotopically determined during the basal and insulin stimulated periods of the clamp. Twenty-four (5 female) hypertensive (blood pressure >75th centile for age and sex) patients with Type 2 diabetes mellitus were studied. Patients were randomized, in a double-blind manner, to either trandolapril 4 mg daily (T) or placebo (P).

RESULTS

Baseline (day 1) systolic (mean +/- SD; P 164+/-14 and T 168+/-13 mm Hg) and diastolic (P 93+/-6, and T 98+/-10 mm Hg) blood pressures were comparable. On days 3 and 21, significant reductions were observed in both groups (P<0.001). In the trandolapril-treated group, serum trandolapril concentrations were >200 pg/ml on days 3 and 21, in all patients apart from one subject at a single visit, while trandolapril was undetectable in the placebo group. Body mass index (BMI) was greater in T compared with P (32.2+/-5.4 v. 28.3+/-4.6, P = 0.07). After correcting for BMI, basal hepatic glucose output (HGO) P 2.6 (95% CI 2.23-3.13) and T 1.91 (1.33-2.51) mg x kg(-1) x min(-1) and clamped HGO P 0.32 (-0.44-1.09) and T 0.87 (0.40-1.34) mg x kg(-1) x min(-1) were similar in both groups. The insulin sensitivity index was comparable in both groups on all days. Total cholesterol concentrations were similar in both groups throughout the study. Triglyceride concentrations were significantly lower in group P 1.38 (1.07-1.68); T 2.14 (1.70-2.58) mmol/l, P<0.01), no significant treatment effect being observed.

CONCLUSIONS

An acute dose and 19 days' continuous treatment with trandolapril resulted in no change in insulin sensitivity or plasma lipid profiles in patients with Type 2 diabetes mellitus and hypertension. These data support the metabolic neutrality of trandolapril in patients with Type 2 diabetes mellitus and hypertension.

Antihypertensive drug therapy and hypoglycemia in elderly diabetic patients treated with insulin and/or sulfonylureas. Gruppo Italiano di Farmacovigilanza nell'Anziano (GIFA)

We performed this case control study to evaluate the risk of hypoglycemia associated with the use of antihypertensive drugs in older hospitalized diabetic patients treated with sulfonylureas and/or insulin. All diabetic patients admitted during 4 months in 1988, month in 1991, 4 months in 1993 and 4 months in 1995 (n = 3477, mean age 71.4 +/- 0.2 years, 1542 males and 1935 females) were enrolled in the study. During the four annual surveys 86 patients (mean age 71.1 +/- 1.4 years, 33 males and 53 females) presented hypoglycemia during hospital stay. The patients who presented hypoglycemia were less frequently users of sulfonylureas and more frequently users of a combination of insulin and sulfonylureas. Use of antihypertensive drugs was similar in the two groups studied, and among potentially interacting drugs considered in the analysis, sulfonamides were more frequently used in patients who experienced hypoglycemia. Moreover, patients with hypoglycemia used a higher number of drugs, had a longer length of stay and had a greater prevalence of hypoglycemia as admission problem. Finally, although not significant, liver and renal diseases were more frequent among patients with hypoglycemia. In the multivariate analysis, contemporary use of insulin and sulfonylureas, liver disease and length of stay were significantly associated with hypoglycemia, while none of the antihypertensive drugs showed a significant association with the occurrence of hypoglycemia during hospital stay. Our results indicate that antihypertensive drugs do not increase the risk of hypoglycemia in elderly diabetic patients.

Drug-induced hypoglycemia

Therapeutically administered antidiabetic drugs, notably insulin and the sulfonylureas, are undoubtedly the most common cause of hypoglycemia encountered in clinical practice. Nevertheless, an impressive list of other drugs can produce hypoglycemia unpredictably in seemingly healthy individuals in whom it may masquerade as spontaneous hypoglycemia. Unless the true cause is identified when the patient is first seen, fruitless and expensive overinvestigation may ensue. The most important drugs are discussed herein and brief mention made of those for which coincidence has not been eliminated.

Association between antihypertensive drug use and hypoglycemia: a case-control study of diabetic users of insulin or sulfonylureas

Antihypertensive drugs are commonly prescribed for the treatment of patients with both diabetes and hypertension. However, the role of selected agents in the development of hypoglycemia remains controversial. The main objective of this study was to evaluate the effect of antihypertensive agents on the risk of hypoglycemia in diabetic patients receiving insulin or sulfonylurea therapy. A matched case-control study was conducted using Pennsylvania Medicaid data. Five control subjects, matched for sex and age, with no reported medical condition of hypoglycemia, were randomly selected for each case patient admitted for hypoglycemia in 1993, resulting in a total of 404 cases and 1375 controls. With these sample sizes, we were able to detect a difference of 10% (P < 0.05) for our primary outcome measure, hospitalization for hypoglycemia. The relative risk of hypoglycemia was estimated using an unconditional logistic regression. The risk of hypoglycemia was 5.5 times greater (95% confidence interval [CI], 4.0 to 7.6) in insulin versus sulfonylurea users and was not influenced by use of angiotensin-converting enzyme (ACE) inhibitors overall. However, use of the ACE inhibitor enalapril was associated with an increased risk of hypoglycemia (odds ratio, 2.4; 95% CI, 1.1 to 5.3) in sulfonylurea users, suggesting that analyzing the unintended side effects of a class of drugs can sometimes mask the adverse effects of individual drugs. Use of beta-blockers was not associated with an increased risk of hypoglycemia, providing further empiric evidence that beta-blockers are an appropriate treatment for persons with concomitant diabetes and hypertension. Per capita health care costs were approximately 3 times higher in patients hospitalized for hypoglycemia compared with controls (P < 0.05). Hospitalization for hypoglycemia is expensive and may be prevented with appropriate monitoring of diabetic patients taking selected antihypertensive agents such as enalapril.

Asthma exacerbations during first therapy with long acting beta 2-agonists

Long-acting beta 2-agonists (LBA) have become an important therapeutic strategy in the treatment of asthma. There is, however, debate whether LBA increase the risk of asthma exacerbations (AE). We studied whether the risk of AE was increased in patients starting LBA therapy and whether the risk was associated with severity. Patients, aged 5-49 years, who were firstly prescribed LBA between 1992 and 1995, and who had at least two consecutive prescriptions of LBA, were selected from the PHARMO-RLS database. The exposure period was the interval between the first and last dispensing of the first exposure episode. The year before the onset was the control period. Single short courses of oral glucocorticosteroids or antibiotics were used as proxy indicators for AE. Severity indicators, assessed in the 6 months before initiation of LBA, were used to classify patients' severity. A total of 788 patients met the inclusion criteria (men: 45.1%, median age: 35). The incidence rate of AE increased significantly (p < 0.001) with severity from 1.7 to 2.4 and 1.1 to 2.7 AE per person year in index and control period, respectively. The risk was merely elevated among patients who start LBA therapy without being treated with other anti-asthma drugs before (RR 1.4, 95% CI 1.0-2.2). First starters of LBA showed no overall change in incidence of AE when compared with the year before starting treatment. A total of 6.9% of patients used LBA as step-one therapy. These patients suffer, in contrast to the whole population, a 40% increased risk of having AE. Although this could be due to confounding, we recommend being reluctant to prescribe LBA to patients who have not been treated before with other anti-asthma drugs.

Comparison of effects of captopril used either alone or in combination with a thiazide diuretic on insulin action in hypertensive Type 2 diabetic patients: a double-blind crossover study

AIMS

It has been suggested that the adverse metabolic effects of antihypertensive therapy offset some of the benefits of blood pressure reduction. It has also been suggested that angiotensin converting enzyme (ACE) inhibitors reduce insulin resistance and that, if used together with thiazide diuretics, the adverse effects of thiazides on insulin sensitivity may be eliminated. We examined the effects on insulin sensitivity of captopril either alone or in combination with bendrofluazide in 11 hypertensive Type 2 diabetic patients.

METHODS

Insulin action was assessed using an isoglycaemic hyperinsulinaemic clamp in a double-blind, randomized, crossover study after a 6-week placebo run-in and following two 12-week treatment periods with captopril (C) (100 mg) alone or in combination with bendrofluazide (CB) (2.5 mg).

RESULTS

Blood pressure was lower following CB compared to C (128/82 vs. 144/ 88 mmHg; P<0.005) and both were lower than baseline (162/101 mmHg; P < 0.001). CB resulted in a significant increase in fasting plasma glucose compared to C (9.7+/-0.8 vs. 8.5+/-0.6 mmol/; P < 0.05). Exogenous glucose infusion rates required to maintain isoglycaemia during hyperinsulinaemia were lower after CB compared to C (22.3+/-2.4 vs. 27.4+/-4.2 mol x kg(-1) x min(-1); P < 0.05). Suppression of endogenous glucose production was reduced after CB compared to baseline (4.0+/-0.6 vs. 2.4+/-0.5 mol x kg(-1) x min(-1); P< 0.05).

CONCLUSIONS

Combination of bendrofluazide with captopril lowered blood pressure but resulted in deleterious effects on insulin action compared to captopril alone.

Metabolic effects of temocapril in hypertensive patients with diabetes mellitus type 2

Compared with other angiotensin-converting enzyme (ACE) inhibitors, the elimination of temocapril is less dependent on renal function. To investigate the metabolic and antihypertensive effects of temocapril in diabetic hypertensives, 30 patients with diabetes mellitus type 2 and mild to moderate hypertension [diastolic blood pressure (BP) 90-115 mm Hg] and without azotemia (plasma creatinine < 180 microM) were evaluated in a prospective randomized double-blind placebo-controlled study. After a 4-week placebo run-in, they received temocapril, 20 mg daily (n = 19), or placebo (n = 11) for 6 weeks. Insulin sensitivity index (SI), determined by the Minimal Model method of Bergman, serum lipoproteins, plasma renin activity, fibrinogen, and microalbuminuria were assessed at the end of the placebo run-in phase and the double-blind treatment phases. Temocapril but not placebo administration produced a significant decrease in supine BP (152/92+/-5/3 vs. 162/98+/-5/2 mm Hg; p < 0.01) and increase in plasma renin (p < 0.05). Variation of SI during temocapril treatment did not reach statistical significance (0.95+/-0.2 before vs. 1.44+/-0.4 x 10(-4)/min/mU/L after treatment). During administration of temocapril or placebo, no significant changes in fasting plasma glucose, insulin, and serum levels of total triglycerides, cholesterol, lipoprotein cholesterol fractions, or fibrinogen were observed. Microalbuminuria decreased significantly on temocapril treatment (49+/-10 vs. 79+/-17 mg/24 h; p < 0.01) but not on placebo. These findings demonstrate that in hypertensive patients with diabetes mellitus type 2, short-term treatment with temocapril is neutral to insulin sensitivity, lipoprotein metabolism, and fibrinogen, and significantly reduces microalbuminuria.

Is captopril-induced improvement of insulin sensitivity mediated via endothelin?

Angiotensin-converting enzyme (ACE) inhibitors have been reported to improve insulin sensitivity during either short-term or long-term administration. Recent studies indicate that endothelin-1 (ET-1) has potent glycogenolytic effects in rat hepatocytes and may cause insulin resistance in rat adipocytes. In addition, ET may also have a role in stimulation of the hypothalamic-pituitary-adrenal axis. To test the hypothesis that part of the effect of captopril in enhancing insulin sensitivity may be mediated via ET and/or by glucocorticoids, we measured 24-h urinary excretion of ET and free cortisol before and after short-term treatment with captopril. The 24-h urinary immunoreactive endothelin (IR-ET) excretion decreased significantly (p < 0.05) from 65 +/- 4 ng at baseline to 42 +/- 3 ng after captopril treatment, whereas no significant change in the 24-h urinary free cortisol excretion was observed. Moreover, no significant change in the 24-h urinary IR-ET and free cortisol excretions was noted in the placebo-treated group. We speculate that ACE inhibitors may exert their effect on insulin sensitivity not only by blocking the renin-angiotensin and kinin systems but also by inhibiting production and/or release of ET.

Antihypertensive treatment with candesartan cilexetil does not affect glucose homeostasis or serum lipid profile in patients with mild hypertension and type II diabetes

This multicentre, randomized, controlled clinical trial assessed the effects of candesartan cilexetil (cand.cil.), a novel angiotensin II antagonist selective for the AT1 receptor with long-lasting antihypertensive activity, compared to placebo on glucose homeostasis and serum lipid profile in mild hypertensives with type II diabetes. A total of 161 men and women, 30-75 years old, with mild hypertension (sitting diastolic blood pressure 90-100 mmHg) and type II diabetes (HbA1c 5.5-9.0%), both measured after a 4-week placebo run-in period, were randomized to double-blind treatment with cand.cil. 8 mg o.i.d. (n = 83) or placebo (n = 78). Dose was increased to 16 mg o.i.d. if diastolic blood pressure remained >90 mmHg. At randomization and after 12 weeks of treatment HbA1c (primary effect variable), blood glucose and the serum lipid profile (including total cholesterol, HDL and LDL cholesterol, triglycerides) were assessed. The statistical analysis of the differences between treatments was based on changes from randomization to the end of the study. Cand.cil. had no significant effect on HbA1c, blood glucose and serum lipids compared to placebo. The median HbA1c both at baseline and after 12 weeks was 7.1% in patients on cand.cil., and 7.2% and 7.1% in patients on placebo. The 95% confidence interval for the median difference in change between the groups was narrow (-0.25; 0.16), including zero, which excluded any clinically important difference. The same held true for blood glucose (-1.10; 0.20), total cholesterol (-0.40; 0.20) and the other lipid parameters. More than 60% of the patients reached a diastolic blood pressure <90 mmHg; adverse events and withdrawals were similar in both groups. Thus, in patients with mild hypertension and type II diabetes, cand.cil. 8-16 mg o.i.d. for 12 weeks does not affect glucose homeostasis and serum lipids. Blood pressure was controlled in most patients, and cand.cil. was well tolerated.

AT1 and AT2 receptor blockade and epinephrine release during insulin-induced hypoglycemia

Angiotensin II facilitates epinephrine release during insulin-induced hypoglycemia, and this effect appears to be independent of type 1 angiotensin II (AT1) receptors in man. In the present study, we hypothesized that the action of angiotensin II on adrenomedullary epinephrine release is mediated by an AT2 receptor-dependent mechanism. In conscious chronically instrumented rats, we measured plasma concentrations of catecholamines during acute insulin-induced hypoglycemia in groups of rats pretreated with the AT1 receptor antagonist losartan (10 mg/kg i.v.), the AT2 receptor antagonist PD123319 (30 mg/kg i.v.), combined losartan + PD123319, the converting enzyme inhibitor enalapril (1 mg/kg i.v.), or vehicle. In vehicle-treated rats, the area under the curve for changes in plasma epinephrine concentration [AUC(plasma epinephrine)] during insulin-induced hypoglycemia was 111+/-8 nmolXh/L (+/-SEM). Pretreatment with losartan alone did not affect AUC(plasma epinephrine) (113+/-17 nmol x h/L), while pretreatment with PD123319 tended to reduce the response (87+/-10 nmol x h/L; P=.08 versus vehicle). However, AUC(plasma epinephrine) was significantly reduced in rats that were pretreated with combined losartan + PD123319 (68+/-5 nmol x h/L; P<.001 versus vehicle) or enalapril: 86+/-10 nmol x h/L (P<.05 versus vehicle). Thus, combined treatment with losartan + PD 123319 proved more effective in attenuating the reflex increase in plasma epinephrine concentration during hypoglycemia than either of the two AT receptor antagonists given alone. We speculate that angiotensin II through binding to both receptor subtypes facilitates the sympathoadrenal reflex response by actions at several anatomical levels of the neural pathways involved in the sympathoadrenal reflex response elicited during insulin-induced hypoglycemia.

Application of the ATC/DDD methodology to monitor antibiotic drug use

In order to monitor the use of antibiotics, it is essential to have comprehensive data on drug consumption. The findings of drug utilisation studies can serve to describe the pattern of drug use in a particular population, to detect areas of concern, and to evaluate the impact of interventions taken to influence the use of drugs. In the present study, the Anatomical Therapeutical Chemical Classification/Defined Daily Doses (ATC/DDD) system developed by the World Health Organisation was evaluated. The system measures the amount of drug used independent of package size and sales price, which allows comparisons not only within an institution but also within a region, a country, or even internationally. Obviously, there can be no modifications of this system. To illustrate the method, the pattern of quinolone use in the general population, in long-term care facilities, and within a single institution was analysed. These drugs were widely used in long-term care facilities in the Nijmegen region of the Netherlands, accounting for about 30% of the antibiotics used in these settings, whereas in the general population as well as in the University Hospital Nijmegen, these drugs constitute only about 6% of the total antibiotics used. These differences are large enough to warrant closer analysis of patterns of antibiotic usage in different settings to identify the reasons for the use of quinolones and to identify measures that might be taken to rationalise the prescription of these drugs.

Randomised placebo-controlled trial of lisinopril in normotensive patients with insulin-dependent diabetes and normoalbuminuria or microalbuminuria. The EUCLID Study Group

BACKGROUND

Renal disease in people with insulin-dependent diabetes (IDDM) continues to pose a major health threat. Inhibitors of angiotensin-converting enzyme (ACE) slow the decline of renal function in advanced renal disease, but their effects at earlier stages are unclear, and the degree of albuminuria at which treatment should start is not known.

METHODS

We carried out a randomised, double-blind, placebo-controlled trial of the ACE inhibitor lisinopril in 530 men and women with IDDM aged 20-59 years with normoalbuminuria or microalbuminuria. Patients were recruited from 18 European centres, and were not on medication for hypertension. Resting blood pressure at entry was at least 75 and no more than 90 mm Hg diastolic, and no more than 155 mm Hg systolic. Urinary albumin excretion rate (AER) was centrally assessed by means of two overnight urine collections at baseline, 6, 12, 18, and 24 months.

FINDINGS

There were no difference in baseline characteristics by treatment group; mean AER was 8.0 micrograms/min in both groups; and prevalence of microalbuminuria was 13% and 17% in the placebo and lisinopril groups, respectively. On intention-to-treat analysis at 2 years, AER was 2.2 micrograms/min lower in the lisinopril than in the placebo group, a percentage difference of 18.8% (95% CI 2.0-32.7, p = 0.03), adjusted for baseline AER and centre, absolute difference 2.2 micrograms/min. In people with normoalbuminuria, the treatment difference was 1.0 microgram/min (12.7% [-2.9 to 26.0], p = 0.1). In those with microalbuminuria, however, the treatment difference was 34.2 micrograms/min (49.7% [-14.5 to 77.9], p = 0.1; for interaction, p = 0.04). For patients who completed 24 months on the trial, the final treatment difference in AER was 38.5 micrograms/min in those with microalbuminuria at baseline (p = 0.001), and 0.23 microgram/min in those with normoalbuminuria at baseline (p = 0.6). There was no treatment difference in hypoglycaemic events or in metabolic control as assessed by glycated haemoglobin.

INTERPRETATION

Lisinopril slows the progression of renal disease in normotensive IDDM patients with little or no albuminuria, though greatest effect was in those with microalbuminuria (AER > or = 20 micrograms/min). Our results show that lisinopril does not increase the risk of hypoglycaemic events in IDDM.