Influence of long-term, low-dose, diuretic-based, antihypertensive therapy on glucose, lipid, uric acid, and potassium levels in older men and women with isolated systolic hypertension: The Systolic Hypertension in the Elderly Program. SHEP Cooperative Research Group

Stepwise increase in the prevalence of isolated systolic hypertension with the stages of chronic kidney disease

BACKGROUND

Hypertension is common in patients with chronic kidney disease (CKD), and isolated systolic hypertension (ISH) accounts for most patients with inadequate blood pressure (BP) control. However, it remains unclear whether the prevalence of ISH would increase with the advancement of CKD.

METHODS

CKD patients of stages 3, 4 and 5 were recruited (n = 324). Based on office systolic BP (SBP) and diastolic BP (DBP), they were classified into any of the four hypertensive subtypes: normotension (SBP/DBP <140/90 mmHg), isolated diastolic hypertension (IDH, SBP <140 mmHg and DBP >or=90 mmHg), ISH (SBP >or=140 mmHg and DBP <90 mmHg) and systolic-diastolic hypertension (SDH, SBP/DBP >or=140/90 mmHg).

RESULTS

The control rate was 45.7% at stage 3, which decreased with the advancement of CKD (control rate was 51.9%, 40.4% and 38.6% in stage 3, 4 and 5, respectively; P < 0.05). The prevalence of IDH changed from 5.0% to 5.3% and 0% from stage 3 to 4 and 5, while there was no significant change in the prevalence of SDH (15.0%, 14.9% and 15.7% at stage 3, 4 and 5, respectively). There was a stepwise increase in the prevalence of ISH with the stages of CKD (it was 28.1%, 39.4% and 45.7% in stage 3, 4 and 5, respectively). Logistic regression showed that age and CKD stages [compared with stage 3, stage 4 and 5 had 2.57 (95% CI 1.04-6.33) and 3.68 (95% CI 1.09-12.47) folds higher risk to develop ISH, respectively] were independent predictors of ISH.

CONCLUSION

The prevalence of ISH increased correspondingly with advanced stages of CKD, which may partially contribute to the increased cardiovascular mortality during the progress of CKD.

Additional small amounts of diuretics improve blood pressure control at low cost without disadvantages in blood sugar metabolism

We evaluated our present treatment of hypertension and sought a way to improve it. We studied 164 of outpatients we treated in 2002. Mean systolic blood pressure (SBP)+/-SD was 142.0+/-11.3, and 56% of patients had SBP over 140 mmHg. We used more diuretics in patients with good control of SBP (19% vs. 7% of patients; p=0.012). After observing our hypertensive patients, we changed our treatment in a goal-oriented manner. Our goal was blood pressure below 140/90 mmHg. We used, in principle, additional small amounts of diuretics for inadequately treated patients. We followed 147 of the 164 patients from 2002 to 2006. During this period, mean SBP decreased to 134.7+/-9.1 mmHg (p<0.001), and the frequency of patients with SBP>140 mmHg decreased to 14% (p<0.001). We used more diuretics in 2006 than in 2002 (12% to 46% p<0.001). To estimate the risks and benefits of diuretics, in 2006 we analyzed 510 patients who had been followed for at least 2 years. Potassium supplementation was needed in 28% of diuretic-treated patients and 7% of patients without diuretics. We found a correlation between the use of diuretics and good SBP control in the entire patient group as well as in patients with diabetes. In the control of diabetes mellitus, we found no statistical difference between patients treated with diuretics and those not. We found diuretics had no adverse effects with respect to new-onset diabetes mellitus.

Treating hypertension while protecting the vulnerable islet in the cardiometabolic syndrome

Hypertension, a multifactorial-polygenic disease, interacts with multiple environmental stressors and results in functional and structural changes in numerous end organs, including the cardiovascular system. This can result in coronary heart disease, stroke, peripheral vascular disease, congestive heart failure, end-stage renal disease, insulin resistance, and damage to the pancreatic islet. Hypertension is the most important modifiable risk factor for major health problems encountered in clinical practice. Whereas hypertension was once thought to be a medical condition based on discrete blood pressure readings, a new concept has emerged defining hypertension as part of a complex and progressive metabolic and cardiovascular disease, an important part of a cardiometabolic syndrome. The central role of insulin resistance, oxidative stress, endothelial dysfunction, metabolic signaling defects within tissues, and the role of enhanced tissue renin-angiotensin-aldosterone system activity as it relates to hypertension and type 2 diabetes mellitus are emphasized. Additionally, this review focuses on the effect of hypertension on functional and structural changes associated with the vulnerable pancreatic islet. Various classes of antihypertensive drugs are reviewed, especially their roles in delaying or preventing damage to the vulnerable pancreatic islet, and thus delaying the development of type 2 diabetes mellitus.

The effect of body mass index on fasting blood glucose after initiation of thiazide therapy in hypertensive patients

BACKGROUND

The prevalence of obesity, hypertension, and type 2 diabetes mellitus is increasing in the United States. In this setting, it is important to understand the effects of antihypertensives on glucose metabolism. We therefore examined the association between body mass index (BMI) (kg/m(2)) and fasting blood glucose (FBG) in subjects in whom thiazide antihypertensive therapy had been initiated.

METHODS

A retrospective observational study was carried out on individuals with hypertension who had been started on thiazide therapy. The subjects' age, thiazide dose, BMI, serum potassium, FBG, new onset of diabetes mellitus, and concurrent use of other antihypertensives were included in the analysis. Predictors of change in FBG were analyzed using multiple linear regression analysis, while predictors of new-onset diabetes mellitus were determined using multiple logistic regression.

RESULTS

A total of 2,624 individuals who had been started on thiazide therapy for hypertension were divided into quartiles of increasing BMI. FBG was found to be associated with baseline BMI and, after thiazide initiation, there was a step-wise increase in the magnitude of change in FBG with increasing BMI (P < 0.001 for both). Analysis using multiple linear regression found that BMI and baseline FBG predicted the magnitude of FBG change in subjects initiated on thiazide treatment (P < 0.001 for both). Analysis with logistic regression found that, after thiazide initiation, BMI, serum potassium baseline (P < 0.05 for both), and baseline FBG (P < 0.001) predicted the development of diabetes mellitus.

CONCLUSIONS

There is an overall increase in FBG in individuals who are started on treatment with thiazides for hypertension. The magnitude of change in FBG and the development of new-onset diabetes mellitus after thiazide initiation were associated with increases in BMI and baseline FBG. American Journal of Hypertension (2008) doi:10.1038/ajh.2007.75American Journal of Hypertension (2008); 21 4. 438-442 doi:10.1038/ajh.2007.75.

Patient complexity: more than comorbidity. the vector model of complexity

BACKGROUND

The conceptualization of patient complexity is just beginning in clinical medicine.

OBJECTIVES

This study aims (1) to propose a conceptual approach to complex patients; (2) to demonstrate how this approach promotes achieving congruence between patient and provider, a critical step in the development of maximally effective treatment plans; and (3) to examine availability of evidence to guide trade-off decisions and assess healthcare quality for complex patients.

METHODS/RESULTS

The Vector Model of Complexity portrays interactions between biological, socioeconomic, cultural, environmental and behavioral forces as health determinants. These forces are not easily discerned but exert profound influences on processes and outcomes of care for chronic medical conditions. Achieving congruence between patient, physician, and healthcare system is essential for effective, patient-centered care; requires assessment of all axes of the Vector Model; and, frequently, requires trade-off decisions to develop a tailored treatment plan. Most evidence-based guidelines rarely provide guidance for trade-off decisions. Quality measures often exclude complex patients and are not designed explicitly to assess their overall healthcare.

CONCLUSIONS/RECOMMENDATIONS

We urgently need to expand the evidence base to inform the care of complex patients of all kinds, especially for the clinical trade-off decisions that are central to tailoring care. We offer long- and short-term strategies to begin to incorporate complexity into quality measurement and performance profiling, guided by the Vector Model. Interdisciplinary research should lay the foundation for a deeper understanding of the multiple sources of patient complexity and their interactions, and how provision of healthcare should be harmonized with complexity to optimize health.

Controversy in diagnosis and management of the metabolic syndrome

Far more work remains to be done to unravel the tangled web of pathophysiology responsible for the metabolic syndrome. This article addresses several aspects of the current controversy surrounding the metabolic syndrome: (1) definition of the metabolic syndrome; (2) evidence for and against the use of the metabolic syndrome as a cardiovascular disease risk predictor; (3) evidence as to underlying pathophysiology; and (4) evidence for treatment of the metabolic syndrome (as opposed to components of the syndrome) in a risk reduction strategy to prevent type 2 diabetes mellitus or cardiovascular disease.

Thiazide-induced subtle renal injury not observed in states of equivalent hypokalemia

Hydrochlorothiazide (HCTZ) is used to manage hypertension and heart failure; however, its side effects include mild hypokalemia, metabolic abnormalities, and volume depletion, which might have deleterious effects on renal and endothelial function. We studied whether HCTZ cause renal injury and/or altered vasoreactivity and if these changes are hypokalemia-dependent. Rats were given a normal diet or a diet moderately low in potassium K+ with or without HCTZ. Animals fed either a low K+ diet alone or HCTZ developed mild hypokalemia. There was no significant difference in systolic blood pressure in the different treatment groups. All three groups with hypokalemia had mild proteinuria; low K(+)-HCTZ rats had reduced creatinine clearance. HCTZ-treated rats displayed hypomagnesemia, hypertriglyceridemia, hyperglycemia, insulin resistance, and hyperaldosteronism. No renal injury was observed in the groups without HCTZ; however, increased kidney weight, glomerular ischemia, medullary injury, and cortical oxidative stress were seen with HCTZ treatment. Endothelium-dependent vasorelaxation was reduced in all hypokalemic groups and correlated with reduced serum K+, serum, and urine nitric oxide. Our results show that HCTZ is associated with greater renal injury for the same degree of hypokalemia as the low K+ diet, suggesting that factors such as chronic ischemia and hyperaldosteronism due to volume depletion may be responsible agents. We also found impaired endothelium-dependent vasorelaxation was linked to mild hypokalemia.

Strategies to improve the cardiovascular risk profile of thiazide-type diuretics as used in the management of hypertension

Thiazide diuretics are one of the preferred pharmacologic treatments for hypertension. However, there has been rather pointed debate during the past 20 years about the clinical significance of the biochemical and/or metabolic adverse effects caused by diuretics. This controversy centers around whether the hypokalemia, hypomagnesemia, hyperuricemia, hyperglycemia and/or hyperlipidemia occasionally seen with diuretics might lessen some of the beneficial effects on cardiovascular risk seen with reductions in blood pressure. One of the biggest controversies in the last few years has focused on whether the small increase in absolute risk of diabetes seen with diuretic therapy should be a concern. The vigilant clinician should appropriately dose and monitor diuretic therapy either when given alone or when used in combination therapy. When these strategies are employed, the adverse effects seen with diuretics can be minimized or negated, and in so doing cardiovascular benefits can be optimized.

Is population-wide diuretic use directly associated with the incidence of end-stage renal disease in the United States?

In the quest for "evidence-based" medicine, an accepted hierarchy of evidence has been proposed. This hierarchy places in vitro studies and animal data at the base, and puts systematic reviews, meta-analyses, and randomized controlled trials at the pinnacle. However, when clinical medicine faces questions that have not yet been studied by the "gold standard" methods, how is one to proceed? Often, the best evidence at hand falls short of randomized controlled trials and meta-analyses. Using this framework, a review of the evidence supporting the hypothesis that population-wide diuretic use is directly associated with end-stage renal disease in the United States is presented. Publications pertaining to diuretic use in recent clinical trials are also discussed.

Update of Diuretics in the Treatment of Hypertension

Diuretics, which are primarily used to modify the volume and the composition of body fluids, are widely used to treat hypertension. The diuretics include a) the thiazides and thiazide-like agents, which are the most common drugs used to treat high blood pressure (these drugs inhibit sodium reabsorption in the early distal convoluted tubule); b) loop diuretics, such as furosemide, block chloride and sodium reabsorption by inhibition of the Na/K/2Cl cotransport system in the thick ascending limb of the loop of Henle; and c) potassium-sparing (retaining) diuretics, including aldosterone receptor blockers (such as spironolactone and eplerenone) and epithelial sodium channel blockers (such as amiloride and triamterene, which interfere with the reabsorption of sodium and excretion of potassium and hydrogen that takes place in the late distal tubule, the connecting tubule, and the cortical collecting duct). Hydrochlorothiazide 12.5 mg once daily or equivalent low dosages of other similar agents reduce blood pressure in approximately one-half to two-thirds of patients who are responsive to this class of drugs; higher doses add little to the effect on blood pressure and also increase side effects. Some combinations of very small doses of thiazide diuretics - for example, 6.25 mg hydrochlorothiazide or 0.625 mg indapamide, with a low dose of an antihypertensive drug of a different class - have average antihypertensive efficacy when used once daily. Furosemide is used in patients with renal failure or severe heart failure and is best given by continuous intravenous infusion. The potassium-sparing diuretics are generally used in combination with thiazide diuretics to treat hypertension. Side effects occur at about the same frequency and severity with equipotent doses of all diuretics. The incidence of side effects is dose-dependent and also increases as a function of the duration of the renal excretory and antihypertensive actions. However, longer-acting diuretics provide better 24-hour control of blood pressure and increase compliance and adherence to the treatment regimen.

Incident diabetes in clinical trials of antihypertensive drugs: a network meta-analysis

BACKGROUND

The effect of different classes of antihypertensive drugs on incident diabetes mellitus is controversial because traditional meta-analyses are hindered by heterogeneity across trials and the absence of trials comparing angiotensin-converting-enzyme (ACE) inhibitors with angiotensin-receptor blockers (ARB). We therefore undertook a network meta-analysis, which accounts for both direct and indirect comparisons to assess the effects of antihypertensive agents on incident diabetes.

METHODS

We undertook a systematic review up to Sept 15, 2006, and identified 48 randomised groups of 22 clinical trials with 143,153 participants who did not have diabetes at randomisation and so were eligible for inclusion in our analysis. 17 trials enrolled patients with hypertension, three enrolled high-risk patients, and one enrolled those with heart failure. The main outcome was the proportion of patients who developed diabetes.

FINDINGS

Initial drug therapy used in the trials (and the number of patients with diabetes of the total number at risk) included: an ARB (1189 of 14,185, or 8.38%), ACE inhibitor (1618 of 22,941, or 7.05%), calcium-channel blocker (CCB, 2791 of 38,607, or 7.23%), placebo (1686 of 24,767, or 6.81%), beta blocker (2705 of 35,745, or 7.57%), or diuretic (998 of 18,699, or 5.34%). With an initial diuretic as the standard of comparison (eight groups), the degree of incoherence (a measure of how closely the entire network fits together) was small (omega=0.000017, eight degrees of freedom). The odds ratios were: ARB (five groups) 0.57 (95% CI 0.46-0.72, p<0.0001); ACE inhibitor (eight groups) 0.67 (0.56-0.80, p<0.0001); CCB (nine groups): 0.75 (0.62-0.90, p=0.002); placebo (nine groups) 0.77 (0.63-0.94, p = 0.009); beta blocker (nine groups) 0.90 (0.75-1.09, p=0.30). These estimates changed little in many sensitivity analyses.

INTERPRETATION

The association of antihypertensive drugs with incident diabetes is therefore lowest for ARB and ACE inhibitors followed by CCB and placebo, beta blockers and diuretics in rank order.

Treatment of Hypertension With Thiazides: Benefit or Damage?Effect of Low- and High-Dose Thiazide Diuretics on Arterial Elasticity and Metabolic Parameters in Hypertensive Patients With and Without Glucose Intolerance

Thiazide diuretics may cause multiple metabolic abnormalities. The authors investigated the effects of varying doses of hydrochlorothiazide (HCTZ) on arterial elasticity and metabolic parameters in patients with hypertension (HTN), HTN and impaired fasting glucose (HTN+IFG), and HTN and type 2 diabetes mellitus (HTN+DM). The patients received low and high doses of HCTZ. Systolic and diastolic blood pressures declined significantly during the first 3 months in all patients, but no additional decrease was seen following the increase in HCTZ dose. In HTN, large artery elasticity index and small artery elasticity increased during the study. In HTN+IFG, large artery elasticity index increased without improvement in small artery elasticity index. In HTN+DM, both large artery elasticity index and small artery elasticity index did not improve during follow-up. Low-dose HCTZ improves arterial elasticity in hypertensive patients, but this effect is diminished with concomitant DM or IFG. The HCTZ dose increase worsened parameters of glucose metabolism and did not further decrease blood pressure or improve arterial elasticity.

Elevated serum uric acid levels in metabolic syndrome: an active component or an innocent bystander?

Elevated serum uric acid (SUA) levels are commonly seen in patients with the metabolic syndrome (MetS). Several mechanisms, both direct and indirect, connect the increased SUA levels with the established diagnostic criteria of MetS. It is possible that the increased cardiovascular disease risk associated with the MetS is partially attributed to elevated circulating SUA concentration. Several drugs used in the treatment of MetS may alter SUA levels. Thus, lifestyle measures together with the judicious selection of drugs for the treatment of hypertension, dyslipidemia, and insulin resistance associated with MetS may result in a reduction of SUA levels and possibly cardiovascular disease risk. This review summarizes the pathophysiologic association between SUA and MetS and focuses on the prevention of hyperuricemia and its cardiovascular consequences.

Systolic hypertension in older persons: how aggressive should treatment be?

Systolic hypertension (SH) is a major public health concern predominantly affecting older persons. A key message of the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7) is that SH is a much more important cardiovascular disease risk factor than diastolic hypertension, particularly in older persons. Consequently, aggressive control of elevations of systolic blood pressure (SBP) is recommended. Despite increasing attention, SH is on the rise: isolated elevations of SBP in a national sampling of Veteran's Administration patients have increased from 57% in 1990 to 1995 to 76% of patients in 1999. This article considers several clinically pertinent issues, including the evidence for treating older patients with elevations in SBP, treating SH in the "oldest old" (those aged >85 years), and how aggressively these patients should be treated. In addition, issues regarding clinical decision making in older patients with SH are discussed.

Effect of antihypertensive agents on the development of type 2 diabetes mellitus

People with hypertension have a high prevalence of insulin resistance and are at relatively high risk of developing type 2 diabetes mellitus. It is becoming increasingly evident that antihypertensive agents have disparate metabolic effects. For example, recent clinical trials indicate that agents that interrupt the renin-angiotensin axis reduce the risk of developing diabetes compared with other classes of antihypertensive agents. Blockade of the effects of angiotensin II might improve blood flow to insulin-sensitive tissues. Furthermore, interruption of the renin-angiotensin system might provide metabolic benefit through such mechanisms as reduced oxidative stress and restored nitric oxide production, which could lead to improved insulin signaling. Alternatively, collective trials suggest that both diuretics and beta-blockers accelerate the appearance of new-onset type 2 diabetes mellitus in patients with hypertension. Therefore, the risk of new-onset diabetes-associated cardiovascular risks should be factored into future treatment recommendations for patients who require antihypertensive therapy. This will become even more important as the number of insulin-resistant patients with hypertension increases in parallel with the steady growth in the number of sedentary, obese, and aged persons in our population.

Antihypertensive medications and blood sugar: theories and implications

Increased rates of diabetes have been reported with thiazide diuretics and beta-blockers, but not with angiotensin-converting enzyme inhibitors, angiotensin receptor blockers or calcium channel blockers. These observations are important because significant glycemic effects of drugs may be a source of accelerated cardiovascular risk that is not detectable during restricted clinical trial follow-up periods. The extent to which diabetes is affected by these medications remains unclear, as is the precise mechanism by which diabetes is promoted. However, several plausible theories are presented herein. Although drug-induced diabetes has been a concern for several years, not enough information is available to influence prescribing for the majority of patients. The number one priority should be controlling blood pressure in a timely manner.

Prevenção do diabetes mellitus tipo 2

Diabetes mellitus do tipo 2 (DM2) é uma doença metabólica complexa, multifatorial e de presença global, que afeta a qualidade e o estilo de vida dos acometidos, podendo levar a uma redução pronunciada na expectativa de vida dessa população. Portadores de diabetes podem ter uma redução de 15 ou mais anos de vida, com a grande maioria morrendo em decorrência das complicações cardiovasculares. Faz-se necessário o estabelecimento de estratégias efetivas para a redução do impacto do DM2 para os próximos anos. Para isso, urge a necessidade de maior atenção no tocante às estratégias de prevenção, sobretudo para as populações de maior risco de desenvolvimento da doença. Nesse contexto, os portadores de tolerância diminuída à glicose (TDG) e glicemia de jejum alterada (GJA) devem, cada vez mais, ser alvos de estratégias de intervenção na busca de minimização de risco para o diabetes, devendo para isso terem direcionamento para a efetivação de mudanças comportamentais (fatores dietoterápicos e prática de atividade física) e, quando necessário e aprovado, o uso de agentes farmacológicos. Estudos conduzidos pelo mundo têm confirmado a eficácia do uso de estratégias comportamentais e mesmo do uso de agentes farmacológicos para a prevenção de DM2.

Drug-induced diabetes mellitus

AIMS

To review the medications that influence glucose metabolism with a focus on hypertensive, transplant and HIV-infected patient populations.

METHODS

Literature obtained from a MEDLINE search from 1970 to present, including studies published in the English language. The search strategy linked drugs, hyperglycaemia and diabetes mellitus, HIV, transplantation, hypertension and psychiatric patients.

RESULTS

Many common therapeutic agents influence glucose metabolism. Multiple mechanisms of action on glucose metabolism exist through pancreatic, hepatic and peripheral effects. The prevalence of hyperglycaemia was higher with the use of thiazide diuretic, beta-blocker, calcineurin, protease inhibitors and atypical antipsychotic drugs.

CONCLUSIONS

Patients treated with those drugs appear to be at increased risk for developing diabetes. It is prudent to monitor plasma glucose values when it is not possible to avoid prescription of medication with known effects on carbohydrate metabolism.

New-onset diabetes and antihypertensive drugs

Observational studies have provided evidence that a consistent fraction (approximately 15-20%) of hypertensive patients displays a glucose intolerance state that may be aggravated by antihypertensive drug regimens based on thiazide diuretics or beta-blockers. This review examines the relative and absolute diabetogenic effects of antihypertensive drugs, by comparing the impact of 'new' (calcium antagonists, angiotensin-converting enzyme inhibitors and angiotensin II receptor antagonists) versus 'old' (diuretics and beta-blockers) drugs on new-onset diabetes in recent clinical trials. Evidence is provided that compared with diuretics and beta-blockers, new-onset diabetes is less common with 'new' drugs, and that conventional antihypertensive compounds, particularly when combined together, may amplify the natural time-dependent tendency towards the development of this metabolic disease. This paper provides new insights into the potential mechanisms responsible for the phenomenon and the clinical significance of antihypertensive drug-induced diabetes.

Relationship between serum uric acid concentration, metabolic syndrome and carotid atherosclerosis

OBJECTIVE

Carotid intima-media thickness (IMT) is a useful surrogate marker of cardiovascular disease. Associations between hyperuricemia, metabolic syndrome and carotid IMT have been reported, but few of the studies have been conducted in a Japanese population.

METHODS

A total of 1,128 subjects (498 men aged, 68+/-14 years and 630 women aged 72+/-12 years) were divided into 4 groups according to serum uric acid (SUA) quartiles. We first investigated the association between SUA concentrations and metabolic syndrome; then, we assessed whether there is an independent association of SUA with carotid IMT in a population subdivided according to gender and metabolic syndrome status.

RESULTS

In women, the prevalence of visceral obesity and metabolic syndrome were significantly increased with increased SUA quartiles, but not in men. After adjusting for age, smoking status, LDL-cholesterol, creatinine and history of diabetes mellitus, the odds ratios (95% CI) of sex-specific quartiles of SUA for metabolic syndrome were 1.0, 1.37 (0.79-2.37), 1.37 (0.79-2.38), and 1.80 (1.03-3.15) in men, and 1.0, 1.04 (0.56-1.94), 2.35 (1.30-4.22), and 2.20 (1.16-4.20) in women. After adjusting for various known risk factors, the prevalence of carotid atherosclerosis (IMT> or =1.0 mm) was higher in subjects in the second, third and fourth quartiles of SUA concentration with odds ratios (95% CI) of 2.41 (1.08-5.37), 3.33 (1.49-7.42), and 2.73 (1.17-6.35), respectively in men without metabolic syndrome but not in men with metabolic syndrome or in women with or without metabolic syndrome.

CONCLUSION

The prevalence of metabolic syndrome was significantly increased according to SUA values only in women. In men without metabolic syndrome, SUA was found to be an independent risk factor for incidence of carotid atherosclerosis.

Hypertension in the Elderly

Hypertension is predictive of a wide variety of subsequent adverse events in elderly patients, at least up to the age of 80 years. Treatment can reduce these adverse outcomes, although the benefits in the very elderly remain somewhat unclear. In the very elderly, there appears to be a reduction in cardiovascular events, but this reduction is perhaps at the expense of an increase in overall mortality. Target BPs in the elderly remain controversial. Among patients who have not had previous stroke or significant cardiovascular or renal disease, the benefits of reducing the SBP below 159 mm Hg are well documented. There is some evidence to suggest, however, that if doing so increases the day-night difference in BP by more than 20% or is associated with a decline in DBP below 65 mm Hg, then the benefits of treatment may be attenuated or lost. In addition, there is some suggestion that reducing SBP consistently below 135 mm Hg may accelerate cognitive decline. There appears to be a role for sodium restriction in those who can comply without otherwise compromising nutrient intake. Likewise, exercise may be beneficial and have benefits beyond simply lowering BP. Weight loss in those who are overweight may also help in lowering the BP. For most patients, low-dose thiazides such as hydrochlorothiazide are likely to be the appropriate first-line therapy (even in patients who have diabetes) unless they exacerbate or precipitate urinary incontinence or gout or complicate concomitant drug therapy (eg, lithium treatment of bipolar disorder). In very elderly patients, the apparent beneficial effects on strokes, major cardiovascular events, and heart failure rates may justify treating despite lack of benefit on overall mortality.

Antihypertensive drugs and incidence of type 2 diabetes: Evidence and implications for clinical practice

The major antihypertensive drug classes appear to exert differing effects on glycemic control and diabetes incidence. Thiazide diuretic and beta-blockers are potentially diabetogenic, whereas calcium channel blockers appear neutral. Inhibitors of the renin-angiotensin system are associated with improvements in glycemic control and may lower diabetes incidence, but it is not clear if this represents a truly preventive effect. Also, it should be noted that previous studies have reported inconsistent results, and the data to date are not definitive. We suggest that inhibitors of the renin-angiotensin system be used as first-line agents in uncomplicated hypertensive patients who are at high risk for developing type 2 diabetes. Thiazides and beta-blockers should not be avoided in patients with compelling indications for these drugs. Many hypertensive patients (particularly those who are obese or have prediabetes) require several agents to achieve target blood pressure levels. Therefore, the choice of initial agent is far less important than ensuring that target blood pressure goals are reached.

Antihypertensive treatment and new-onset diabetes mellitus

The various antihypertensive regimens have varying effects on glucose metabolism and the development of diabetes mellitus. Recent large hypertension trials have shown great differences in the development of new-onset diabetes among antihypertensive drug therapies. The incidence of diabetes is unchanged or increased by thiazide diuretics and b-adrenergic blockers, and unchanged or decreased by angiotensin-converting enzyme inhibitors, calcium channel blockers, and angiotensin-receptor blockers. The differences in new-onset diabetes mellitus have not influenced the outcome of cardiovascular mortality and morbidity in all of the large clinical trials, but drug-induced diabetes among hypertensive patients is known to carry the same cardiovascular risk as that seen in patients with previously known diabetes; however, it might take years for the increased risk to become apparent.

Effects of hydrochlorothiazide and propranolol treatment on chylomicron metabolism in hypertensive subjects

Modifications in chylomicron metabolism caused by antihypertensive drugs were investigated in hypertensive subjects because previous studies had indicated that diuretics and beta-blockers modify the plasma lipid concentrations through mechanisms that were not fully understood. A triglyceride-rich emulsion resembling lymph chylomicrons, labeled with (3H) triolein and (14C) cholesteryl oleate, was infused intravenously into mildly hypertensive patients after 8 weeks on placebo and subsequently on hydrochlorothiazide (n = 10) or propranolol (n = 8). The residence time of both radioactivities in plasma was utilized for the simultaneous calculation of the particle remnant removal rate and of the lipoprotein lipase activity expressed as a delipidation index = 1 – [(3H) triolein residence time/(14C) cholesteryl oleate residence time]. Treatment with hydrochlorothiazide diminished the delipidation rate value whereas propranolol mildly increased the removal rate of the remnant particle. These alterations of the chylomicron kinetics were not accompanied by changes in plasma triglycerides, glucose, and insulin concentration as measured in the fasting state. The impairment of the lipoprotein lipase activity by thiazides and the faster removal rate of the whole particle by propranolol could explain the reason why in previous clinical studies the simultaneous use of these drugs does not aggravate the hyperlipidemia known to be induced by thiazides alone. Key words: hydrochlorothiazide, propranolol, hypertension, plasma lipoproteins, chylomicron metabolism.

[Differential pressure as an independent factor of cardiovascular risk]

OBJECTIVES

To confirm that high differential pressure (DP) supposes greater risk of ischaemic cardiopathy and to assess whether it is also an independent risk factor of suffering a cerebrovascular accident.

DESIGN

An analytical, observational, retrospective and longitudinal study with historic cohorts.

SETTING

Urban population of about 18 000 inhabitants.

PARTICIPANTS

300 patients aged between 15 and 75 with hypertension of > or =2 years evolution, who have had their blood pressure taken by nurses 4 or more times (excluding casualty) and have not suffered a cardiovascular event (CVE), whether coronary accident, cerebrovascular accident or peripheral vasculopathy.

MAIN MEASUREMENTS

The history relating to cardiovascular risk was recorded: lipaemia, obesity, tobacco dependency, diabetes mellitus, left ventricular hypertrophy (LVH). These factors were considered present if their diagnosis preceded the CVE diagnosis. They were placed in 2 groups, depending on the degree of differential pressure: "high" if >60 mm Hg and "not high" if (3/4)60 mm Hg. They were analysed for intention to treat over 10 years, with the appearance or not of a CVE as a response variable.

RESULTS

300 participants (73.3% women), 150 exposed to risk and 150 not exposed. The initial analysis showed significant differences between the 2 groups for age (P<.0001), diabetes (P<.0001), and LVH (P<.001). After logistic regression, the OR of suffering LVH was 2.38 (95% CI, 1.19-4.74) in the group with high DP; the OR of ischaemic cardiopathy, 2.84 (95% CI, 1.16-6.96); and of cerebrovascular accident, 2.70 (95% CI, 1.09-6.68). There were no significant differences for peripheral arteriopathy.

CONCLUSIONS

DP was confirmed as an independent factor of cardiovascular risk and, despite the limitations of the study, it was pointed to as a possible independent factor of cerebrovascular risk.

Hypertension and atherosclerosis: clinical implications from the ALLHAT Trial

By failing to recognize the heterogeneity of hypertension, the authors of the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) study used a faulty premise to conduct a poorly designed clinical trial. By failing to control blood pressures equally across study drug groups, ALLHAT cannot be considered to be a definitive comparative trial. Being neither a monotherapy trial nor a trial that initiated therapy for blood pressure control, ALLHAT provided no data to recommend first-line therapy for hypertension, making the conclusions invalid. Thiazide-type diuretics increase angiotensin II and consequently promote atherosclerosis and arteriolarsclerosis. Angiotensin-converting enzyme inhibitors and angiotensin receptor blockers retard atherosclerosis and are nephroprotective. Multiple randomized controlled trials show beneficial clinical outcomes, including cardioprotection and nephroprotection, with the use of angiotensin-converting enzyme inhibitors and angiotensin receptor blockers. These agents, and not thiazide-type diuretics, should be used as first-line agents to retard the process of atherosclerosis and its clinical outcomes in the setting of arterial hypertension.

Control of hypertension in adults with chronic kidney disease in the United States

Although improved control of hypertension is known to attenuate progression of chronic kidney disease (CKD), little is known about the adequacy of hypertension treatment in adults with CKD in the United States. Using data from the Fourth National Health and Nutrition Survey, we assessed adherence to national hypertension guideline targets for patients with CKD (blood pressure <130/80 mm Hg), we assessed control of systolic (<130 mm Hg) and diastolic (<80 mm Hg) blood pressure, and we evaluated determinants of adequate blood pressure control. Presence of CKD was defined as glomerular filtration rate <60 mL/min per 1.73 m2 or presence of albuminuria (albumin:creatinine ratio >30 microg/mg). Multivariable logistic regression with appropriate weights was used to determine predictors of inadequate hypertension control and related outcomes. Among 3213 participants with CKD, 37% had blood pressure <130/80 mm Hg (95% confidence interval [CI], 34.5% to 41.8%). Of those with inadequate blood pressure control, 59% (95% CI, 54% to 64%) had systolic >130 mm Hg, with diastolic < or =80 mm Hg, whereas only 7% (95% CI, 3.9 to 9.8%) had a diastolic pressure >80 mm Hg, with systolic blood pressure < or =130 mm Hg. Non-Hispanic black race (odds ratio [OR], 2.4; 95% CI, 1.5 to 3.9), age >75 years (OR, 4.7; 95% CI, 2.7 to 8.2), and albuminuria (OR, 2.4; 95% CI, 1.4 to 4.1) were independently associated with inadequate blood pressure control. We conclude that control of hypertension is poor in participants with CKD and that lack of control is primarily attributable to systolic hypertension. Future guidelines and antihypertensive therapies for patients with CKD should target isolated systolic hypertension.

Treatment of microalbuminuria in patients with type 2 diabetes mellitus

The incidence of type 2 diabetes mellitus is increasing world-wide, and is now one of the leading causes of end-stage renal disease in Western countries. Type 2 diabetes mellitus is also a major risk factor for cardiovascular events. Therefore, the early identification of patients at greatest risk, and the subsequent initiation of renal and cardiovascular protective treatments, are of the utmost importance. Microalbuminuria refers to a subclinical increase in urinary albumin excretion. By definition it corresponds to an albumin excretion rate of 20 to 200 microg/min (30 to 300 mg/day) or an albumin to creatinine ratio (mg/mmol) of 2.5 to 25 in males and 3.5 to 35 in females. Microalbuminuria is an important clinical finding because it is not only associated with an increased risk of progression to overt proteinuria (macroalbuminuria) and renal failure, but also cardiovascular events. In patients who progress to overt nephropathy, microalbuminuria usually precedes macroalbuminuria by an interval of 5 to 10 years. In patients with type 1 diabetes mellitus, blood pressure increases and renal function declines after the onset of macroalbuminuria. However, in patients with type 2 diabetes mellitus, hypertension and a decline in renal function may occur when albumin excretion is still in the microalbuminuric range. Large clinical trials have demonstrated that achieving tight glycemic (i.e. glycosylated hemoglobin < 7.0%) and blood pressure (i.e. < 130/85mm Hg) control retards the progression of renal disease. There is accumulating evidence to suggest that the use of antihypertensive agents which target the renin-angiotensin system (RAS) can slow the progression of renal disease and provide cardioprotection in patients with type 2 diabetes mellitus and microalbuminuria. Antihypertensive agents which target the RAS also appear to have advantages over and above reductions in systemic blood pressure. In summary, the annual screening of patients with type 2 diabetes mellitus for microalbuminuria, and the initiation of measures to retard the progression of renal and cardiovascular disease, are now considered part of routine clinical practice. In particular, the finding of microalbuminuria should provoke an intensified modification of the common risk factors for renal and cardiovascular disease, that is hyperglycemia, hypertension, dyslipidemia and smoking. Antihypertensive therapy in patients with microalbuminuria and type 2 diabetes mellitus should be initiated with angiotensin converting enzyme (ACE) inhibitors or angiotensin-II type 1 receptor antagonists.

Plasma triglycerides and type III hyperlipidemia are independently associated with premature familial coronary artery disease

OBJECTIVES

This study was designed to explore contributions of plasma total triglycerides (TGs) and type III hyperlipidemia to the risk of premature familial coronary artery disease (CAD).

BACKGROUND

Although plasma TGs are recognized as a risk factor for CAD, the independence of this association from related risk factors remains controversial. Also, the degree of CAD risk conferred by excess remnants of TG-rich lipoproteins in type III hyperlipidemia remains unclear.

METHODS

We analyzed lipids by ultracentrifugation in a series of 653 cases with premature familial CAD (myocardial infarction or revascularization by age 55 years in men or age 65 years in women, with similar onset in at least one other first-degree relative) and in 1,029 control subjects. The relationship of CAD risk to various strata of plasma TGs, high-density lipoprotein (HDL) cholesterol, and type III hyperlipidemia, and interactions among these variables were examined by multiple logistic regression, adjusting for other CAD risk factors.

RESULTS

The odds ratio for CAD with elevated plasma TG rose progressively to 11.4 in those with TGs 500 to 799 mg/dl (95% confidence interval 3.4 to 38.0, p < 0.0001) compared with <100 mg/dl, even after correction for HDL cholesterol, other elements of the metabolic syndrome, and other CAD risk factors. Risk of CAD associated with type III hyperlipidemia (found in 3.4% of cases) was also markedly increased independent of other risk factors (odds ratios of 5 to 10 depending on the model, all with p < 0.002).

CONCLUSIONS

The association between the plasma TG level and premature familial CAD is strong, graded, and independent. Risk of CAD is also strikingly elevated with type III hyperlipidemia.

A systematic review of drug therapy to delay or prevent type 2 diabetes

OBJECTIVE

To systematically review the evidence for the prevention of type 2 diabetes by pharmacological therapies.

RESEARCH DESIGN AND METHODS

Randomized controlled trials and cohort studies examining the effect of oral hypoglycemic agents, antiobesity agents, antihypertensive agents, statins, fibrates, and estrogen on the incidence of type 2 diabetes were identified from MEDLINE, EMBASE, the Cochrane Controlled Trials Registry, and searches of reference lists. Two reviewers independently assessed studies for inclusion and performed data extraction.

RESULTS

Ten studies of oral hypoglycemic agents and 15 studies of nonoral hypoglycemic agents were found. Oral hypoglycemic agents and orlistat are the only drugs that have been studied in randomized controlled trials with diabetes incidence as the primary end point. In the largest studies of 2.5-4.0 years' duration, metformin (relative risk [RR] 0.69, 95% CI 0.57-0.83), acarbose (0.75, 0.63-0.90), troglitazone (0.45, 0.25-0.83), and orlistat (hazard ratio [HR] 0.63, 95% CI 0.46-0.86) have all been shown to decrease diabetes incidence compared with placebo; however, follow-up rates varied from 43 to 96%. Current evidence for statins, fibrates, antihypertensive agents, and estrogen is inconclusive. In addition, the critical question of whether drugs are preventing, or simply delaying, onset of diabetes remains unresolved.

CONCLUSIONS

Currently, no single agent can be definitively recommended for diabetes prevention. Future studies should be designed with diabetes incidence as the primary outcome and should be of sufficient duration to differentiate between genuine diabetes prevention as opposed to simple delay or masking of this condition.

A cost-minimization analysis of diuretic-based antihypertensive therapy reducing cardiovascular events in older adults with isolated systolic hypertension

BACKGROUND: Hypertension is among the most common chronic condition in middle-aged and older adults. Approximately 50 million Americans are currently diagnosed with this condition, and more than $18.7 billion is spent on hypertension management, including $3.8 billion for medications. There are numerous pharmacological agents that can be chosen to treat hypertension by physicians in clinical practices. The purpose of this study was to assess the cost of alternative antihypertensive treatments in older adults with isolated systolic hypertension (ISH). METHOD: Using the Systolic Hypertension in the Elderly Program (SHEP) and other data, a cost-minimization analysis was performed. The cost was presented as the cost of number-needed-to treat (NNT) of patients for 5 years to prevent one adverse event associated with cardiovascular disease (CVD). RESULT: It was found that the cost of 5 year NNT to prevent one adverse CVD event ranged widely from $6,843 to $37,408 in older patients with ISH. The incremental cost of the 5 year NNT was lower to treat older patients in the very high CVD risk group relative to patients in the lower CVD risk group, ranging from $456 to $15,511. Compared to the cost of the 5 year NNT of other commonly prescribed antihypertensive drugs, the cost of SHEP-based therapy is the lowest. The incremental costs of the 5 year NNT would be higher if other agents were used, ranging from $6,372 to $38,667 to prevent one CVD event relative to SHEP-based drug therapy. CONCLUSION: Antihypertensive therapy that is diuretic-based and that includes either low-dose reserpine or atenolol is an effective and relatively inexpensive strategy to prevent cardiovascular events in older adults with isolated systolic hypertension. Use of the diuretic-based therapy is the most cost-effective in patients at high risk for developing cardiovascular disease.

Long-term effect of diuretic-based therapy on fatal outcomes in subjects with isolated systolic hypertension with and without diabetes

Diuretic-based antihypertensive therapy is associated with the development of diabetes but with improved clinical outcomes. It has been proposed that the duration of clinical trials has been too short to detect the adverse effects of diabetes. We assessed the long-term mortality rate of subjects in the Systolic Hypertension in the Elderly Program (n = 4,732) who were randomized to stepped-care therapy with 12.5 to 25.0 mg/day of chlorthalidone or matching placebo. If blood pressure remained above the goal, atenolol or matching placebo was added. At a mean follow-up of 14.3 years, cardiovascular (CV) mortality rate was significantly lower in the chlorthalidone group (19%) than in the placebo group (22%; adjusted hazard ratio [HR] 0.854, 95% confidence interval [CI] 0.751 to 0.972). Diabetes at baseline (n = 799) was associated with increased CV mortality rate (adjusted HR 1.659, 95% CI 1.413 to 1.949) and total mortality rate (adjusted HR 1.510, 95% CI 1.347 to 1.693). Diabetes that developed during the trial among subjects on placebo (n = 169) was also associated with increased CV adverse outcome (adjusted HR 1.562, 95% CI 1.117 to 2.184) and total mortality rate (adjusted HR 1.348, 95% CI 1.051 to 1.727). However, diabetes that developed among subjects during diuretic therapy (n = 258) did not have significant associations with CV mortality rate (adjusted HR 1.043, 95% CI 0.745 to 1.459) or total mortality rate (adjusted HR 1.151, 95% CI 0.925 to 1.433). Diuretic treatment in subjects who had diabetes was strongly associated with lower long-term CV mortality rate (adjusted HR 0.688, 95% CI 0.526 to 0.848) and total mortality rate (adjusted HR 0.805, 95% CI 0.680 to 0.952). Thus, chlorthalidone-based treatment improved long-term outcomes, especially among subjects who had diabetes. Subjects who had diabetes associated with chlorthalidone had no significant increase in CV events and had a better prognosis than did those who had preexisting diabetes.

Latin American consensus on diabetes mellitus and hypertension

Diabetes mellitus and hypertension, responsible of a major burden of cardiovascular complications, are increasing their incidence in Latin America in similar proportions to the rest of the world. The metabolic syndrome, a strong predictor of both diabetes and hypertension deserves more attention from the primary care physicians. Evidence based and updated guidelines on detection, prevention and treatment of diabetes and hypertension, issued by local experts, are willing to inform and translate these recommendations to the clinical practice of physicians assisting these patients throughout Latin America.

Rational pharmacotherapy in the diabetic hypertension: analysis-prescribing patterns in a general hospital in Taiwan

OBJECTIVES

To examine prescribing at a 2800-bed hospital, also providing ambulatory services for 9000 visits per day, with a view to assessing the extent to which it followed international guidelines for treating diabetic hypertension.

METHOD

Patients receiving antidiabetic and antihypertensive drugs concomitantly during the 4-week study period were included.

RESULT

Of the 5015 eligible patients, most received combination antidiabetic therapy. Oral antidiabetic agents used alone or in combination included (in descending order) metformin, glibenclamide, gliclazide, glipizide, glimepiride and alpha-glucosidase inhibitors. Gliclazide accounted for most of the oral antidiabetic drug expenditure. Sulfonylurea plus metformin was the most popular regimen. Prescriptions for long-acting sulfonylureas did not differ between elderly and younger patients. For blood pressure control, calcium-channel blockers were most commonly used alone and overall, although current guidelines suggest that they should be second-line treatments. Inappropriate use of immediate-release nifedipine was noted. The combination, atenolol >100 mg/day and hydrochlorothiazide 50 mg/day (or an equivalent) were extensively used. Among 54.7% patients treated with combination antihypertensives, calcium-channel blockers and an angiotensin-converting enzyme inhibitor were most commonly used.

CONCLUSION

Most diabetic hypertensive patients were treated with combination therapy for glucose and blood pressure control. Prescriptions for antihypertensive drugs often differed from current guidelines, especially in the choice of agents and their combinations.

Pharmacologic prevention or delay of type 2 diabetes mellitus

OBJECTIVE

To evaluate the current data on pharmacologic interventions intended to prevent or delay the onset of type 2 diabetes mellitus.

DATA SOURCES

Searches of MEDLINE (1966-July 2002) and an extensive manual review of journals were performed using the key search terms diabetes mellitus, metformin, acarbose, troglitazone, orlistat, nateglinide, risk reduction, and prevention.

STUDY SELECTION AND DATA EXTRACTION

All articles identified from the data sources were evaluated, and all information deemed relevant was included for this review. Randomized controlled trials and meta-analyses were included if the primary outcome measure was prevention of diabetes and/or change in the rate of progression to diabetes.

DATA SYNTHESIS

Type 2 diabetes mellitus is a growing epidemic. Major risk factors include obesity, impaired glucose tolerance, and impaired fasting glucose. Complications of diabetes result in significant morbidity and mortality and are a substantial public health issue. Four randomized, blinded, controlled trials have assessed the efficacy of different medications, including metformin, troglitazone, acarbose, and orlistat, at decreasing the risk of progression to diabetes in patients at risk for developing diabetes. All of these agents decreased the risk of progression to diabetes.

CONCLUSIONS

Metformin, troglitazone, acarbose, and orlistat have been shown to decrease the risk of progression to diabetes in patients at risk for developing diabetes. Other questions that address issues such as identifying target populations, cost-effectiveness, and screening strategies must be answered to more fully define the place of pharmacologic therapy to prevent or delay diabetes.

Hypertension in the elderly

High blood pressure, once believed to represent a normal and progressive component of the aging process, is now recognized as a manifestation of structural and physiologic abnormalities of aortic function. Elevated systolic blood pressure and increased pulse pressure unquestionably increase the risk of both fatal and nonfatal cardiovascular events, including stroke, myocardial infarction, and heart failure. Isolated systolic hypertension, defined as a systolic blood pressure >/= 140 mm Hg with a diastolic blood pressure < 90 mm Hg, affects most individuals aged 60 years and older. Several clinical trials have clearly demonstrated that treatment of hypertension significantly reduces the cardiovascular event rate. However, controversy continues as to the choice of antihypertensive agents and combinations of agents. It is both appropriate and necessary to treat elderly hypertensives aggressively to the same target blood pressures identified for younger patients. It is also appropriate to initiate treatment with lower doses of antihypertensive agents and to bring the pressure down more slowly, monitoring for orthostatic hypotension, impaired cognition, and electrolyte abnormalities.

Prevalence of hyperuricemia and relation of serum uric acid with cardiovascular risk factors in a developing country

BACKGROUND

The prevalence of hyperuricemia has rarely been investigated in developing countries. The purpose of the present study was to investigate the prevalence of hyperuricemia and the association between uric acid levels and the various cardiovascular risk factors in a developing country with high average blood pressures (the Seychelles, Indian Ocean, population mainly of African origin).

METHODS

This cross-sectional health examination survey was based on a population random sample from the Seychelles. It included 1011 subjects aged 25 to 64 years. Blood pressure (BP), body mass index (BMI), waist circumference, waist-to-hip ratio, total and HDL cholesterol, serum triglycerides and serum uric acid were measured. Data were analyzed using scatterplot smoothing techniques and gender-specific linear regression models.

RESULTS

The prevalence of a serum uric acid level >420 micromol/L in men was 35.2% and the prevalence of a serum uric acid level >360 micromol/L was 8.7% in women. Serum uric acid was strongly related to serum triglycerides in men as well as in women (r = 0.73 in men and r = 0.59 in women, p < 0.001). Uric acid levels were also significantly associated but to a lesser degree with age, BMI, blood pressure, alcohol and the use of antihypertensive therapy. In a regression model, triglycerides, age, BMI, antihypertensive therapy and alcohol consumption accounted for about 50% (R2) of the serum uric acid variations in men as well as in women.

CONCLUSIONS

This study shows that the prevalence of hyperuricemia can be high in a developing country such as the Seychelles. Besides alcohol consumption and the use of antihypertensive therapy, mainly diuretics, serum uric acid is markedly associated with parameters of the metabolic syndrome, in particular serum triglycerides. Considering the growing incidence of obesity and metabolic syndrome worldwide and the potential link between hyperuricemia and cardiovascular complications, more emphasis should be put on the evolving prevalence of hyperuricemia in developing countries.

Trials in isolated systolic hypertension: an update

Isolated systolic hypertension (ISH) has proved to be a powerful predisposing factor for cardiovascular diseases in the elderly. Recent placebo-controlled interventional trials such as the Systolic Hypertension in the Elderly Program, the Systolic Hypertension in Europe, and the Systolic Hypertension in China showed that the lowering of systolic blood pressure using a diuretic- or a calcium antagonist-based treatment is associated with a decrease in cardiovascular events. Antihypertensive therapy was found especially effective in preventing stroke in the elderly with ISH. A slowing in the progression of dementia was observed in patients randomized to a calcium antagonist-based treatment. Patients at high cardiovascular risk such as those with diabetes benefited the most from treatment. In another trial performed in patients with left ventricular hypertrophy (Losartan Intervention For Endpoint Reduction), a subset of patients had ISH. In those patients, an angiotensin II antagonist-based treatment was superior to a b-blocker-based treatment in preventing cardiovascular complications. The experience accumulated in patients with ISH showed that combination therapy is often required to control blood pressure. Overall, the evidence available today indicates that pharmacologic treatment of ISH markedly improves the outcome of elderly patients.

Antihypertensive therapy and incidence of type 2 diabetes: a systematic review

OBJECTIVE

To systematically review the available evidence examining the effects of the major antihypertensive drug classes on the incidence of type 2 diabetes.

RESEARCH DESIGN AND METHODS

The Cochrane Controlled Trials Register, Medline, and Embase were searched for English-language case-control, cohort, and randomized controlled trials involving the major antihypertensive classes and reporting type 2 diabetes as an end point. Reference lists of original studies and narrative reviews were also hand searched. One reviewer (R.P.) performed the electronic searches. Both reviewers independently extracted data and assessed all potentially relevant studies for inclusion and methodological quality. Abstracts were not included, and unpublished studies were not sought.

RESULTS

One case-control study, 8 cohort studies, and 14 randomized controlled trials met inclusion criteria. No study examined diabetes incidence as a primary end point. Poor methodological quality limits the conclusions that can be drawn from most nonrandomized trials. Evidence from randomized studies is also potentially limited by several sources of bias, including treatment contamination and bias inherent in post hoc analyses. Data from the highest-quality studies suggest that diabetes incidence is unchanged or increased by thiazide diuretics and beta-blockers and unchanged or decreased by ACE inhibitors, calcium channel blockers, and angiotensin receptor blockers.

CONCLUSIONS

The major antihypertensive classes may exert differential effects on diabetes incidence, although current data are far from conclusive. Ongoing placebo-controlled randomized trials involving potentially beneficial drug classes and examining diabetes incidence as a primary end point should provide more definitive evidence.

Use of Calcium Channel Antagonists for the Treatment of Hypertension in the Elderly

Systolic blood pressure and pulse pressure increase continuously throughout adult life and the prevalence of arterial hypertension rises accordingly, reaching 53-78% among those aged 65-74 years. Estimates of the prevalence of isolated systolic hypertension in the elderly range from 34-65%, with more women than men affected. It has been shown that within all age groups a difference in usual systolic blood pressure of 20 mm Hg or a difference in usual diastolic blood pressure of 10 mm Hg is associated with an approximately 2-fold difference in the risk of dying from stroke or ischaemic heart disease. Intervention trials using predominantly diuretics and/or beta-adrenoceptor antagonists have proven the efficacy and tolerability of antihypertensive treatment in elderly patients. For many years there have been ongoing discussions about the safety of calcium channel antagonists, especially in patients with diabetes mellitus. However, according to a recently published large prospective, randomised, double-blind, controlled clinical trial with more than 33,000 patients enrolled, no indications for increased total mortality, cancer rate or gastrointestinal bleeding for participants on amlodipine, a long-acting dihydropyridine calcium channel antagonist, were found. With calcium channel antagonists, protective effects against cardiovascular disease have been proven in large trials with elderly patients, particularly against stroke. There is good evidence to suggest that calcium channel antagonists may be superior to other antihypertensive agents in diabetic patients with isolated systolic hypertension. These agents are well tolerated and probably delay the progression of dementia. The lack of adverse metabolic effects that, in the case of a diuretic-based regimen, may have important long-term implications concerning cardiovascular risk, make calcium channel antagonists an attractive choice when antihypertensive treatment decisions need to be made in a predominantly overweight or obese elderly population.

New-onset diabetes and antihypertensive therapy: comments on ALLHAT trial

The development of new-onset diabetes is frequent during the follow-up of treated hypertensive patients. The prevalence of such an event seems to differ depending on the type of antihypertensive therapy used to control blood pressure. Diuretics and b-blockers and their association are particularly harmful in this regard. On the contrary, calcium channel blockers, angiotensin-converting enzyme inhibitors and angiotensin receptor blockers, alone or in association with diuretics, are associated with a lower prevalence of this metabolic complication. These statements are confirmed by data from the Antihypertensive and Lipid Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) study. Long-term studies are required to determine the relevance of development of new-onset diabetes in treated hypertensive patients.