Effects of diltiazem on serum lipids, exercise performance and blood pressure: randomized, double-blind, placebo-controlled evaluation for systemic hypertension

Frailty and maximal exercise capacity in adult lung transplant candidates

BACKGROUND

Frail lung transplant candidates are more likely to be delisted or die without receiving a transplant. Further knowledge of what frailty represents in this population will assist in developing interventions to prevent frailty from developing. We set out to determine whether frail lung transplant candidates have reduced exercise capacity independent of disease severity and diagnosis.

METHODS

Sixty-eight adult lung transplant candidates underwent cardiopulmonary exercise testing (CPET) and a frailty assessment (Fried's Frailty Phenotype (FFP)). Primary outcomes were peak workload and peak aerobic capacity (V˙O₂). We used linear regression to adjust for age, gender, diagnosis, and lung allocation score (LAS).

RESULTS

The mean ± SD age was 57 ± 11 years, 51% were women, 57% had interstitial lung disease, 32% had chronic obstructive pulmonary disease, 11% had cystic fibrosis, and the mean LAS was 40.2 (range 19.2-94.5). In adjusted models, peak workload decreased by 10 W (95% CI 4.7 to 14.6) and peak V˙O₂ decreased by 1.8 mL/kg/min (95% CI 0.6 to 2.9) per 1 unit increment in FFP score. After adjustment, exercise tolerance was 38 W lower (95% CI 18.4 to 58.1) and peak V˙O₂ was 8.5 mL/kg/min lower (95% CI 3.3 to 13.7) among frail participants compared to non-frail participants. Frailty accounted for 16% of the variance (R²) of watts and 19% of the variance of V˙O₂ in adjusted models.

CONCLUSION

Frailty contributes to reduced exercise capacity among lung transplant candidates independent of disease severity.

Hypertension in Athletes and Active Populations

Hypertension continues to be the most common cardiovascular disorder in the USA and worldwide. While generally considered a disorder of aging individuals, hypertension is more prevalent in athletes and the active population than is generally appreciated. The timely detection, diagnosis, and appropriate treatment of hypertension in athletes must focus on both adequately managing the disorder and ensuring safe participation in sport while not compromising exercise capacity. This publication focuses on appropriately diagnosing hypertension, treating hypertension in the athletic population, and suggesting follow-up and participation guidelines for athletes.

A randomized controlled trial of the effects of aerobic dance training on blood lipids among individuals with hypertension on a thiazide

PURPOSE

Hypertension is associated with dyslipidemia. Thiazides adversely affect serum lipid levels in hypertensives. There is currently a dearth of information on benefits of aerobic exercise training on serum lipid levels in individuals on thiazides and this study aimed at bridging this gap in knowledge.

METHODS

This randomized-controlled trial involved 120 newly-diagnosed adults with essential hypertension (≥65 years). They were treated with 50 mg of hydrochlorothiazide + 5 mg of hydrochloride amiloride and 5 or 10 mg of amlodipine for 4-6 weeks before they were randomly assigned into exercise group (EG) and control croup (CG). Only EG underwent 12-week aerobic dance training at 50-70 % of heart rate reserve three times per week. Low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol, triglyceride and total cholesterol were measured and recorded at baseline and post-study.

RESULTS

Eighty-eight (45 in EG and 43 in CG) of 120 participants randomly assigned to groups completed the study. Systolic (p = 0.370) and diastolic (p = 0.771) blood pressures (BP) were similar between the two groups at baseline. Systolic (p < 0.001) and diastolic (p < 0.001) BPs reduced significantly in exercise and control groups. LDL-C (from 120.10 ± 33.41 to 110.50 ± 31.68 mg/dl; p = 0.037) and triglyceride (from 117.49 ± 45.12 to 100.63 ± 35.42 mg/dl; p = 0.002) decreased in EG post-study but no significant between-group differences were observed.

CONCLUSIONS

Although, LDL-C and triglyceride are reduced after aerobic dance training, they were not any more than without it. Aerobic dance training has favorable effects on LDL-C, triglyceride, and systolic and diastolic BP in individuals with hypertension on a thiazide.

Treatment of hypertension in athletes: an evidence-based review

Hypertension is the most common cardiovascular condition in adults. It is also very common in athletes. When lifestyle changes fail, medications may be needed for the treatment of hypertension. When choosing a drug for antihypertensive therapy, providers should choose an agent that has favorable effects on blood pressure and minimal detrimental hemodynamic change during exercise. Evidence supports that the medications with the most favorable effects are angiotensin-converting enzyme inhibitors, calcium channel blockers, alpha-blockers, and cardiac-selective beta-blockers. The effects of diuretics are less desirable, and nonselective beta-blockers should be a last choice for hypertensive patients who are physically active.

Exercise in hypertension. A clinical review

The current exercise prescription for the treatment of hypertension is: cardiovascular mode, for 20-60 minutes, 3-5 days per week, at 40-70% of maximum oxygen uptake (VO2(max)). Cardiovascular exercise training is the most effective mode of exercise in the prevention and treatment of hypertension. Resistance exercise is not the preferred mode of exercise treatment, but can be incorporated into an exercise regime provided the diastolic blood pressure response is within safe limits. It is inconclusive whether durations longer than 30 minutes produce significantly greater reductions in blood pressure. A frequency of three exercise sessions per week has been considered to be the minimal frequency for blood pressure reduction. Higher frequencies tended to produce greater reductions, although not significantly different. Evidence still exists that high intensity exercise (>75% VO2(max)) may not be as effective as low intensity exercise (<70% VO2(max)) in reducing elevated blood pressures. Exercise can be effective without a change in bodyweight or body fat. Bodyweight or body fat loss and anti-hypertensive medications do not have an added effect on blood pressure reduction associated with exercise. beta-blockade is not the recommended anti-hypertensive medication for effective exercise performance in non-cardiac patients. Not all hypertensive patients respond to exercise treatment. Differences in genetics and pathophysiology may be responsible for the inability of some hypertensive patients to respond to exercise. Ambulatory technology may allow advances in individualising a more effective exercise prescription for low-responders and non-responders.

Cyclosporine plasma unbound fraction in heart and lung transplantation recipients

To investigate the variability in the unbound fraction (fu) of cyclosporine in recipients of heart, heart-lung, and lung transplantation, cyclosporine fu was determined ex vivo in plasma by equilibrium dialysis. In a retrospective study, 260 samples of plasma (one to seven per patient) were obtained from 89 heart (86%), lung (9%), and heart-lung (5%) transplant patients. The unbound fraction (x100) of cyclosporine ranged from 0.52% to 3.94%, with an overall mean of 1.53%+/-0.375% (SD). The mean percentage unbound for individual patients ranged from 0.71% to 1.98%, giving a 2.8-fold interpatient variation. In heart transplant recipients (66 patients), the values of fu were significantly lower (p < 0.01) during more severe rejection episodes, which required antirejection treatment (endomycardial biopsy result of grade 3a and higher) than in the absence of rejection (grade 0) or during grade la rejections. The value of fu did not vary with organ transplanted (p = 0.35) or etiology of organ failure (p = 0.32). Cyclosporine fu was negatively correlated with the age of the patient (r = -0.18, p < 0.05). Correlations were not observed between fu and blood biochemical and cytologic indices. However, fu was significantly lower (p < 0.01) in hypercholesterolemic transplant recipients (1.37+/-0.52%) than in normocholesterolemic patients (1.60+/-0.63%). Administration of simvastatin resulted in a significant increase in the mean fu from 1.40+/-0.09%) to 1.82+/-0.13% (paired t test, n = 13; p < 0.01). In patients who received ketoconazole, fu was not different from controls. These findings suggest that the level of cyclosporine fu may be an important determinant of immunosuppressive activity of cyclosporine. Moreover, the variation in fu could be strongly related to the concentration of serum lipoproteins; interpretation of the results of cyclosporine monitoring thus requires consideration of the lipidemic status of the patient.

Effects of antihypertensive drugs on cholesterol metabolism of human mononuclear leukocytes and hepatoma cells

OBJECTIVES

Primary prevention trials of antihypertensive therapy have shown conflicting results on coronary events. Potential interference of antihypertensive agents with cellular lipid metabolism may alter the atherosclerotic risk of individuals.

DESIGN AND METHODS

The effects of the calcium antagonist's verapamil, diltiazem, and nifedipine and of the beta-blockers propranolol and metoprolol on low density lipoprotein (LDL) receptor activity, cholesterol esterification rate, oleate incorporation in triglycerides and sterol synthesis were studied in freshly isolated human leukocytes and HEP G2 cells.

RESULTS

Up to a concentration of 3-10 mumol/L, verapamil, propranolol, and metoprolol led to an increased cellular content of 125I-LDL by an inhibition of degradation. In mononuclear cells verapamil stimulated accumulation and degradation. No effect on binding was observed. Diltiazem was only stimulatory on 125I-LDL processing in leukocytes. Beta blockers and verapamil significantly reduced the LDL mediated 14C-oleate incorporation in cholesterol esters. In the presence of 25-hydroxycholesterol the esterification was not diminished, which suggests that cholesterolacyltransferase (ACAT) was not affected per se. Whereas all the agents induced the synthesis of lanosterol, metoprolol inhibited cholesterol synthesis. None of the agents had a significant influence on 14C-oleate incorporation in triglycerides, suggesting a specific influence on cholesterol metabolism.

CONCLUSIONS

Antihypertensive drugs affect the cholesterol metabolism on a cellular level. Mechanisms are an interference with degradation of LDL and consequent alterations of cholesterol esterification. Using leukocytes as peripheral cells and HEP G2 as a model of human liver, these results may have importance when antihypertensive long-term therapy is conducted for primary or secondary prevention of atherosclerotic complications.

A comparative study on the effects of Gemfibrozil, Diltiazem and Isosorbide dinitrate on lipid profile in patients of ischemic heart disease in India

Effects of three drugs, Gemfibrozil, Diltiazem and lsosorbide dinitrate (ISDN) on various lipid parameters were studied in patients with ischemic heart disease (IHD) with positive treadmill stress response. Gemfibrozil and diltiazem significantly lowered the levels of serum total lipids (TL), triglycerides (TG), phospholipids (PL), total cholesterol (TC), low density lipoprotein cholesterol (LDL-C) and very low density lipoprotein cholesterol (VLDL-C), and incroased the levels of serum high density lipoprotein cholesterol (HDL-C) significantly. However, patients administered with ISDN showed a significant increase in all the lipid parameters except HDL-C, which showed a significant decrease.

Metabolic effects in rats of verapamil alone and in combination with captopril

The metabolic effects of verapamil alone and in combination with captopril were investigated in rats. Animals received the maximum recommended doses for humans (per kg body weight per day) over a 2-week period. Verapamil had no significant effects on serum biochemistry, but caused a significant increase in serum potassium level and significant reductions in the rates of intestinal absorption of glucose and calcium. Verapamil/captopril had a number of significant effects on serum lipid profile (increased total cholesterol, increased HDL-cholesterol, and reduced LDL-cholesterol), and also provoked an increase in serum alanine amino-transferase activity and in serum glucose levels. The combination treatment caused a significant increase in serum chloride levels, but had no effect on intestinal absorption.

Cardiac conduction with diltiazem and beta-blockade combined. A review and report on cases

Sinus arrest or atrioventricular block are rare but serious adverse effects of diltiazem. The risk of developing such adverse reactions may be somewhat exacerbated by concomitant beta-adrenergic blocker therapy. In patients with hypertension or coronary heart disease, combination therapy with diltiazem and a beta-blocker usually enhances therapeutic benefit relative to monotherapy, but adverse effects attributable to this combination, especially in patients with left ventricular dysfunction or latent cardiac conduction deficits, may be limiting. Therefore, such combination therapy may not be suitable in patients with atrioventricular block grade I, bradycardia or hypotension, and patients on the combined therapy should always have their blood pressure, heart rate and atrioventricular conduction on ECG monitored. If combination therapy with diltiazem and propranolol or metoprolol is commenced, or in the case of impaired renal function, an adjustment of the beta-blocker dosage may be required. Clinical studies on the combined use of diltiazem and beta-adrenergic blockers mostly concern the treatment of angina pectoris in patients with coronary heart disease. Although very few cases of severe bradycardia and conduction abnormalities have been reported in patients with uncomplicated hypertension on diltiazem and beta-blockade combination, there seems to be a potential for the occurrence of significant conduction disturbances with the combined treatment, and precautions should apply also for hypertensive populations.

Prostaglandin I2-mediated upregulation of 125I-LDL-receptor binding by isradipine in normo- and hypercholesterolemic rabbits in vivo

The in-vivo low-density lipoprotein (LDL)-uptake by the liver was monitored during the initial 60 minutes after injection of radiolabelled LDL. LDL-uptake by the liver as evidenced by the liver/blood pool ratio in normocholesterolemic male New Zealand white rabbits (44.2 +/- 3.1% of whole body activity) was almost double as compared to the ones fed a 1% cholesterol enriched diet (22.5 +/- 3.3%). The blood disappearance of 125I-LDL was significantly faster in normocholesterolemic animals. A 4-week treatment with the dihydropyridine calcium channel blocker isradipine resulted in a significantly enhanced LDL-binding by the liver, both in normo- and hypercholesterolemic animals to a comparable extent. A concomitant acetylsalicylic acid (ASA) treatment completely abolished the benefit induced by isradipine while ASA alone was ineffective. Similarly, 125I-LDL disappearance from blood was improved by isradipine, while ASA neutralizes this effect. Again, ASA alone did not change the kinetics. Plasma cholesterol and high-density lipoprotein (HDL) cholesterol remained unchanged. Isradipine significantly enhanced vascular prostaglandin(PG)I2-generation while concomitant ASA treatment or ASA application alone almost completely depressed PGI2-formation. It is concluded that the improved LDL-binding by the liver is due to an enhanced PGI2-formation evoked by isradipine.

Sexual dimorphism in the metabolic response to the calcium channel antagonists, diltiazem and clentiazem, by hyperlipidemic JCR:LA-cp rats

The JCR:LA-cp rat is obese, insulin resistant, and hypertriglyceridemic. The obese male rats spontaneously develop atherosclerosis and ischemic myocardial lesions that are prevented by treatment with the calcium channel antagonist, nifedipine. Male and female JCR:LA-cp rats were treated with the calcium channel antagonist, diltiazem, and a closely related compound, clentiazem (at 30 mg/kg). Clentiazem, but not diltiazem, caused a significant increase in body weight of both sexes in the presence of decreased food consumption. Serum triacylglycerols were decreased by half by both drugs in male rats only, reflecting decreased very-low-density lipoprotein (VLDL) secretion. Females did not respond with lower concentrations of triacylglycerol (although VLDL secretion rate was decreased) and showed increased concentrations of cholesterol in the high-density lipoprotein (HDL) fraction. Diltiazem-treated male rats showed decreased VLDL particle size, together with a shift to shorter-chain fatty acids in the triacylglycerols. This effect was not seen with clentiazem treatment. There was no effect on insulin and glucose metabolism in these insulin-resistant animals. Calcium channel antagonists have complex metabolic effects in the hypertriglyceridemic rats, with highly beneficial hypolipidemic effects in the males that are not seen in the females. The sexual dimorphism of these responses is sex linked, but appears not to be due to the steroid sex hormones. These results suggest caution in the chronic treatment of human females with these agents and the importance of detailed human studies in females and individuals with the insulin-resistant/hypertriglyceridemic/obese syndrome.

Diltiazem: ten years of clinical experience in the treatment of hypertension

Diltiazem hydrochloride is a benzothiazepine derivative calcium-channel blocker with proven antianginal and antihypertensive capabilities. Its primary mechanism of action is vasodilatation, which results in diminished vascular resistance and improved perfusion to various vascular beds and target organs. The antihypertensive efficacy of diltiazem in various demographic groups has been studied and compared with diuretics, beta-blockers, angiotensin-converting enzyme inhibitors, and other calcium-channel blockers. These studies have shown that the antihypertensive effect of diltiazem is similar to that of the other therapies. Diltiazem does not adversely affect electrolytes or carbohydrate or lipid metabolism, and it may have beneficial effects on the heart and kidneys. Diltiazem reduces myocardial hypertrophy and exerts antianginal effects on the heart through coronary vasodilation and reduction in the blood pressure double product. Diltiazem improves renal perfusion and attenuates proteinuria. These effects may be helpful in limiting the progression of renal injury. Overall, the efficacy and tolerability of diltiazem, as well as its salutary effects on the heart and kidneys, make it an important therapeutic consideration for patients with hypertensive disease.

Management of Hypertension

In brief Current recommendations for brief managing mild to very severe high blood pressure need to be adapted for the special concerns of physically active patients. First-line treatment involves dietary changes, smoking cessation, and aerobic exercise. The next step is to add drug therapy, and diuretics and beta-blockers are the initial drugs of choice because of their proven long-term efficacy. Diuretics may, however, produce hypokalemia or dehydration, and beta- blockers may cause hyperkalemia, reduce exercise capacity, or increase perceived exertion. Other antihypertensive agents may be preferable in specific situations.

Effects of atenolol and diltiazem-SR on exercise and pressure load in hypertensive patients

The effects of monotherapy with atenolol or diltiazem-SR on blood pressure, 24-h blood pressure (BP) load, and exercise capacity were tested in patients with mild to moderate (stages I and II) essential hypertension. After 3-week single-blind placebo therapy, patients with sitting diastolic blood pressure (SDBP) of 94-114 mmHg were randomized to atenolol 50 mg/day (62 patients) or diltiazem-SR 90 mg b.i.d. (60 patients) in a double-blind parallel study. Depending on SDBP response, the dose was increased to 100 mg/day for atenolol and 180 mg b.i.d. for diltiazem-SR. Twenty-four-hour ambulatory blood pressure measurements and exercise tolerance test by the Bruce protocol were done at the end of placebo and active treatment. Compared with placebo, both atenolol and diltiazem-SR significantly decreased heart rate (HR), sitting systolic blood pressure (SSBP), SDBP, ambulatory BP, BP load for waking and sleeping hours, area under the BP curve, rate-pressure product (p < 0.001), and exercise time (NS). Atenolol exerted a greater effect on ambulatory BP, HR, rate-pressure product, waking diastolic BP load, and area under the 24-h BP curve. The drugs were well tolerated and caused no serious side effects necessitating discontinuation of treatment. These findings indicate that (1) monotherapy for hypertension with atenolol or diltiazem-SR is effective and well tolerated, (2) it decreases the 24-h BP load, (3) it does not interfere with exercise capacity.

The Nordic Diltiazem Study (NORDIL). A prospective intervention trial of calcium antagonist therapy in hypertension

NORDIL--the Nordic diltiazem intervention study was started in September 1992. This trial is a prospective randomized open blinded-endpoint (PROBE) multicenter, parallel-group study conducted in Norway and Sweden. The study is designed to evaluate the potential preventive effects of diltiazem compared with conventional antihypertensive drug treatment. Primary endpoints are cardiovascular mortality defined as fatal acute myocardial infarction, fatal acute cerebrovascular disease (stroke), sudden death and other fatal cardiovascular disease as well as cardiovascular morbidity defined as myocardial infarction and cerebrovascular disease (stroke). Secondary endpoints are total mortality, the development or deterioration of ischaemic heart disease, congestive heart failure, atrial fibrillation, transient ischaemic attacks, diabetes mellitus and renal insufficiency. Male and female patients, aged 50-69, with primary hypertension are randomly allocated to therapy starting with either diltiazem (180-360 mg daily) or conventional treatment (diuretics or beta-adrenergic blockers). Add-on therapy in the conventional treatment group excludes all types of calcium antagonists. The goal of treatment will be a target diastolic blood pressure of < or = 90 mmHg or a 10% diastolic blood pressure reduction. The NORDIL study will allow the detection of a 20% difference in cardiovascular mortality between the two groups with a power of 80% at the 5% significance level (two-sided test). A total of 12,000 patients will be recruited from about 480 primary Health Care Centers or hospital based Hypertension Units. Patients will be treated for an average period of 5 years.

Variability in plasma lipoprotein profiles when comparing diltiazem and propranolol

OBJECTIVE

To examine the effects of diltiazem and propranolol on plasma lipoproteins in a double-blind, comparative trial.

PATIENTS

Twenty-one mild-to-moderate hypertensive patients.

METHODS

Following discontinuation of previous antihypertensive treatments, and a 4-week, single-blind, placebo run-in, subjects were randomized to receive sustained-release diltiazem or propranolol. Total cholesterol, high-density lipoproteins (HDL), low-density lipoproteins (LDL), and very-low-density lipoproteins (VLDL) were measured during placebo administration and after 12-16 weeks of treatment.

RESULTS

No significant changes in plasma lipoprotein concentrations were noted in either the diltiazem or propranolol group compared with baseline values or each other. Marked variation in HDL, LDL, and VLDL were noted following drug treatment and in eight subjects whose lipoprotein concentrations were remeasured prior to drug treatment during the placebo period. The alterations were bidirectional, and similar in magnitude to those found following drug treatment.

CONCLUSIONS

In many cases, changes in plasma lipoproteins reported to be a consequence of antihypertensive treatment may merely reflect normal intrapatient variability.

A multicenter comparison of nicorandil and diltiazem on serum lipid, apolipoprotein, and lipoprotein levels in patients with ischemic heart disease

The effects of nicorandil and diltiazem on serum lipid, apolipoprotein, and lipoprotein levels in 37 patients with ischemic heart disease were examined in a randomized, multicenter study. Nicorandil (n = 20, 10-40 mg/day, b.i.d.) and diltiazem (n = 17, 60-240 mg/day, b.i.d.) were administered for 12 weeks. Both nicorandil and diltiazem administration showed an effective antianginal effect. Diltiazem administration showed a significant hypotensive action. There were no significant changes in serum lipids, apolipoproteins, and lipoproteins for both nicorandil and diltiazem. There were no significant changes in body weight, uric acid, and fasting blood sugar levels during the test period for both drugs. These data show that nicorandil, like diltiazem, does not have any adverse effects on lipid metabolism and that it is a favorable drug to use as an agent for treating arteriosclerotic heart disease.

Antihypertensive therapy

Choosing antihypertensive agents that protect patients against cardiovascular and other complications is a growing trend in the treatment of mild to moderate hypertension. Calcium channel blockers and angiotensin-converting enzyme (ACE) inhibitors are favored because they have neutral or positive effects on lipid levels and insulin resistance. The alpha 1 blockers, especially doxazosin mesylate (Cardura), are enjoying a resurgence in popularity because they have a beneficial effect on lipid levels. In terms of preserving patients' quality of life, the ACE inhibitors in particular have been shown to have a positive impact. It has been shown that systolic hypertension in elderly patients should definitely be treated, but the most appropriate agent has yet to be defined. Therapy should be tailored to the individual. The following questions should be considered when choosing an antihypertensive agent: (1) What are its side effects (especially metabolic ones)? (2) Does it require only once- or twice-a-day dosing? (3) Does it cause regression of left ventricular hypertrophy? (4) Does it prevent death from coronary artery disease? (5) How will it affect quality of life? (6) How much does it cost? The goal of therapy should be to provide adequate blood pressure control throughout the day, enhance compliance, and protect the heart, brain, and kidneys without adversely affecting metabolic state.

Calcium antagonists for the treatment of systemic hypertension

As shown by large-scale clinical trials, the antihypertensive effectiveness of diuretics has been associated with a dramatic decrease in the incidence of stroke. This decrease, however, has not been accompanied by a similar reduction in atherosclerotic complications of hypertension, perhaps because other risk factors are important contributors to cardiovascular disease. In particular, a pathophysiologic relationship appears to exist between high blood pressure, left ventricular hypertrophy, diabetes and dyslipidemia. Thus, metabolically neutral antihypertensive agents such as calcium antagonists, which have no adverse effects on serum lipids and insulin sensitivity and can reduce left ventricular mass, are particularly suitable for the treatment of hypertension and attendant cardiovascular complications.

The effects of verapamil on training in patients with ischemic heart disease

Verapamil is a calcium-channel blocking agent with antianginal and antiarrhythmic properties that have been widely studied. Its myocardial depressant effect is well known. The purpose of this study was to examine the effects of verapamil on the training response in patients with ischemic heart disease. The study group consisted of 41 male patients with a mean age of 53.3 +/- 7.2 years who had suffered a myocardial infarction or had undergone coronary artery bypass surgery 8 to 12 weeks previously. They were chosen on a consecutive basis from eligible patients entering a cardiac rehabilitation program. With use of a double-blind technique, 21 patients were assigned to receive verapamil, 120 mg three times daily, while the other 20 were given an identical placebo. Each patient underwent exercise stress testing in the untreated state to permit comparison between tests performed on commencement and completion of training. The training effect was determined by comparing exercise response before and after the eight-week program. There was an increase in exercise duration (p less than 0.001) and a decrease in functional aerobic impairment (p less than 0.001), without difference between the two groups. Energy expenditure increased in both groups, but the highest level was achieved by those receiving active treatment (p less than 0.02). Heart rate for equal workload was significantly reduced after training (p less than 0.001), although this was lower in the placebo patients (p less than 0.001) and the patients who had a recent myocardial infarction (p less than 0.01). It appears that treatment with verapamil does not impair the development of a training effect in patients with ischemic heart disease who are undergoing organized training.

Effects of nifedipine GITS and atenolol monotherapy on serum lipids, blood pressure, heart rate, and weight in mild to moderate hypertension

Forty-nine patients, with ages ranging from eighteen to seventy years and with mild to moderate primary hypertension (sitting diastolic blood pressure of greater than or equal to 95 mmgH and less than or equal to 115 mmHg) were randomized into a twenty-one-week, double-blind, prospective study to determine the effects of monotherapy of nifedipine GITS (gastrointestinal therapeutic system) versus atenolol on serum lipids, lipid subfractions, apolipoproteins, (apo), and blood pressure (BP). Nifedipine GITS and atenolol significantly reduced blood pressure, but nifedipine GITS reduced sitting and standing systolic BP significantly more than atenolol (p = .001). Sitting and standing heart rate decreased significantly (p = 0.001) during atenolol therapy but did not change significantly during nifedipine GITS therapy. Atenolol increased weight (mean change + 2.2 lb; p = 0.011), but nifedipine GITS decreased weight (mean change - 2.4 lb; p = 0.07). Nifedipine GITS had a more favorable effect on the lipid profile. High density lipoprotein cholesterol (HDL-C) and HDL2 subfractions were increased significantly (p = .001) as were apo A1 (p = 0.037) and apo A2 (p = 0.025). Nifedipine GITS increased HDL3 (NS), reduced triglycerides (TG) (NS), and had no significant effect on total cholesterol (TC) low density lipoprotein cholesterol (LDL-C) and apo B. Atenolol significantly increased serum total cholesterol (p = 0.039) and HDL-C and HDL2 (p = 0.049 and 0.048 respectively). Atenolol increased TG (NS) and apo B (NS) with little change in apo A1 and apo A2. It is concluded that nifedipine GITS had equal or better antihypertensive efficacy than atenolol and had a more favorable effect on the lipid profile. These effects may offer advantages in reducing CHD risk.

Once daily compared with twice daily administration of slow-release diltiazem as monotherapy for hypertension

We compared the efficacy of the antihypertensive drug diltiazem in a slow release formulation administered once daily with its twice daily administration as monotherapy in 34 patients with mild to moderate essential hypertension. All subjects received placebo for three weeks before the randomised, double blind, crossover study, and their supine diastolic blood pressure (BP) ranged from 95 mmHg to 115 mmHg. After the patients had received the placebo for three weeks diltiazem was titrated in the open label treatment to either 120 mg or 180 mg twice daily until the target BP level was achieved. After the open three weeks' of treatment with diltiazem twice daily patients were allocated randomly for either once daily or twice daily administration. After a six week, double blind period, the treatment was changed according to the crossover design. With a dose of 120 mg or 180 mg twice daily patients' supine and standing BP readings were significantly lower than when they took the drug once daily. In the subgroup (n = 19) with the maximum dose of diltiazem given twice daily and once daily BP levels were lower in those subjects on twice daily treatment than in those treated once a day with the same total daily dose, the differences being significant. Administration of diltiazem once a day in a slow release formulation was not as effective as a twice daily dose when the dose titration was greatest or when compared with the same dosage (240 mg x 1/day or 120 mg x 2/day).

Antihypertensive monotherapy with tablet (prompt-release) diltiazem: multicenter controlled trials

The tablet formulation of diltiazem has been available for the treatment of angina pectoris but has not been comprehensively evaluated in hypertension. This study's aim was to evaluate the efficacy, dose-response characteristics, and duration of action of tablet (prompt-release) diltiazem in mild to moderate hypertension. Three placebo-controlled trials were designed. The first (trial #1) evaluated the dose response of 120, 240, and 360 mg/day (q12h regimen) of diltiazem in parallel fixed-dose fashion using hourly blood pressures. The second (trial #2) evaluated a q12h titration from 240 to 360 mg/day, which could be switched to q8h. The third (trial #3) evaluated a q8h titration from 180 to 270 to 360 mg/day, followed by conversion to a q12h regimen. The goal was a supine diastolic blood pressure of less than 90 mmHg and 10 mmHg less than baseline. With doses of diltiazem increasing from 120 to 240 to 360 mg/day, there was a progressive decrease in the average mean arterial pressure, describing a dose response with 120 mg/day as the ineffective dose. The peak effect for each dose regimen was found at 6 hours, with significant reductions lasting over 10 hours in the 240 mg/day and 360 mg/day groups. Peak plasma concentrations occurred at 3 hours. The residual effect at the trough of the 240 mg/day and 360 mg/day doses was 48% and 53% of the peak effect, respectively. When titration was carried out on a q8h regimen, both systolic and diastolic blood pressures were significantly decreased. When the regimen was switched from q8h to q12h, the effect was not maintained.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of short- and long-term administration of nifedipine on serum lipoprotein metabolism in patients with mild hypertension

The effects of short- and long-term administration of nifedipine on serum lipids, lipoproteins, and apolipoproteins (apo) were studied. Administration of nifedipine capsule for 4 months significantly decreased triglycerides and increased the HDL2 cholesterol and the HDL2/HDL3 cholesterol ratio. No significant changes in serum lipids and lipoproteins were observed during short-term therapy with slow-release nifedipine tablets. Following administration of tablets for 24 months, the LDL/HDL cholesterol ratio, apo B, and apo B/apo A-I ratio increased at 12 months, but reverted to baseline values at 24 months. Apo E levels were decreased significantly at 24 months. No significant changes were noted in total cholesterol, triglyceride, HDL cholesterol, HDL2,3 cholesterol, apo A-I, apo A-II, apo C-II, or apo C-III levels during long-term therapy with slow-release nifedipine tablets. These results indicate that nifedipine has a neutral or even favorable effect on lipoprotein metabolism. However, a prospective well-controlled study would be required to finally establish this effect. This finding strengthens the indications for using nifedipine as a first-line drug in the long-term treatment of hypertension.

Hypertension

In brief When exercise alone does not NMM control hypertension, a medical ISMS regimen can be used in conjunction with exercise or other nonpharmacologic interventions. Diuretics, beta blockers, calcium antagonists, and angiotensin-converting enzyme (ACE) inhibitors are widely used to treat hypertension. ACE inhibitors and calcium antagonists are good choices for exercising patients because they do not limit exercise performance and have few side effects. The author gives guidelines for changing the regimen from exercise alone to exercise and medication, and for stepping down from medical therapy.

Management of the patient with a low HDL-cholesterol

While there is epidemiologic evidence linking a low high-density lipoprotein (HDL) cholesterol level with coronary disease events, and interventions that raise HDL while lowering low-density lipoprotein (LDL) cholesterol levels have been shown to reduce subsequent coronary events, there are no studies showing benefit from raising HDL when a low HDL level is the sole lipid abnormality. HDL is thought to play a key role in reverse cholesterol transport, removing lipids from peripheral cells, but the precise role of HDL in cholesterol metabolism is not understood. The measurement of HDL levels has not been well standardized. Reliance on ratios relating HDL to LDL or to total cholesterol may be misleading in the management of patients. It has not been shown that measuring HDL subfractions or apolipoprotein levels is superior to measuring total HDL levels in predicting coronary risk. HDL levels may be raised by hygienic measures such as smoking cessation and exercise, but a considerable amount of exercise over a long period of time is required. Alcohol consumption and weight loss through dieting inconsistently raise HDL. Estrogen therapy raises and progestational agents lower HDL. Certain beta-blocking drugs lower HDL levels. For the patient with an isolated low HDL level the hygienic measures may be advised, but drug therapy such as nicotinic acid or gem-fibrozil should be prescribed only when low HDL is accompanied by elevated LDL levels that are unresponsive to diet and hygienic measures.

The effects of clonidine hydrochloride versus atenolol monotherapy on serum lipids, lipid subfractions, and apolipoproteins in mild hypertension

The study objective was to determine the effects of monotherapy with clonidine and atenolol versus placebo on serum lipids, apolipoproteins, and blood pressure in patients with mild primary hypertension. The protocol comprised a double blind, randomized, placebo-controlled 5-month prospective study carried out in an outpatient general internal medicine clinic in a university medical center. There were 92 patients ages 18 to 70, with mild primary hypertension (sitting diastolic blood pressure of greater than 90 mm Hg and less than 105 mm Hg) without significant cardiac, renal, cerebrovascular, hepatic, neoplastic, or hematologic disorders. Patients with severe hyperlipidemia or peripheral vascular disease were also excluded. All factors known to effect serum lipids were held constant throughout the study (i.e., diet, weight, exercise, caffeine, tobacco). Atenolol and clonidine significantly reduced blood pressure when compared with placebo. Atenolol caused significant increases in serum triglycerides and apolipoprotein B (p less than 0.05) and significant reductions in high-density lipoprotein-cholesterol, apolipoproteins A-I and A-II (p less than 0.05). Atenolol also induced a significant adverse effect on all lipid ratios, increasing total cholesterol/high density lipoprotein-cholesterol, low density lipoprotein-cholesterol/high density lipoprotein-cholesterol, apolipoprotein B/apolipoprotein A-I and apolipoprotein B/apolipoprotein A-II ratios and decreasing low density lipoprotein-cholesterol/apolipoprotein-B ratio (p less than 0.05). Clonidine caused significant reductions in high-density lipoprotein-cholesterol, apolipoproteins AI and AII (p less than 0.05 but was neutral on all other lipids, lipid subfractions, and apolipoproteins. Clonidine did not significantly alter any of the lipid ratios.(ABSTRACT TRUNCATED AT 250 WORDS)

General considerations in selecting antihypertensive agents in patients with type II diabetes mellitus and hypertension

The Working Group on Hypertension in Diabetes recommends starting pharmacologic treatment of hypertension with a small dose of a thiazide, beta-blocker, prazosin hydrochloride, angiotensin-converting enzyme inhibitor, or calcium channel blocker. Thus, these alternatives are regarded as first-line treatment in hypertensive patients with diabetes mellitus. Both thiazides and beta-blockers can cause deterioration in glycemic control and have an unfavorable influence on the lipoprotein profile. These metabolic side effects may partly counteract beneficial effects. Non-selective beta-blockers should probably be avoided in diabetic patients, since blockade of the beta-2 receptor may be associated with a compromise in peripheral blood flow and with problems associated with hypoglycemia. Cardioselective beta-blockers, which may have primary preventive effects on coronary disease, are beneficial in this patient group. In patients with non-insulin-dependent diabetes mellitus without nephropathy or overt fluid retention, diuretic therapy could be replaced by sodium restriction and/or calcium channel blocker therapy, since these agents also have a mild diuretic effect. Calcium channel blockers, angiotensin-converting enzyme inhibitors, and prazosin hydrochloride have minimal metabolic side effects, making them suitable for treatment of hypertension in this patient group.

Metabolic considerations in the approach to diabetic hypertensive patients

The effects of antihypertensive drugs on glucose metabolism are an important consideration in the selection of pharmacologic therapy for diabetic patients. Diuretics can elevate blood glucose levels, aggravate glucose intolerance, and predispose diabetic patients to hyperosmolar non-ketotic coma. Beta-blocking drugs often exacerbate and prolong insulin-induced hypoglycemia in diabetics. Beta-blockers may also cause hyperglycemia. Central agonists, alpha-blockers, and vasodilators apparently have neutral effects on carbohydrate metabolism in normal subjects or in hypertensive diabetics. Calcium channel blockers may disturb carbohydrate metabolism in diabetic patients. Angiotensin-converting enzyme inhibitors have little effect on glucose metabolism. Because diabetic patients are prone to fluid, electrolyte, hormone, and lipid disturbances, it is important to consider the effects of antihypertensive drugs on these aspects of metabolism when selecting pharmacologic therapy. The effects of various antihypertensive drugs on sodium, calcium, magnesium, and acid/base balance are reviewed. The effects of these drugs on serum uric acid and potassium, as well as on hormone and lipid levels, are also considered.

The evolution of antihypertensive therapy: an overview of four decades of experience

Hypertension is a major public health problem amendable to treatment. Numerous large scale clinical trials have demonstrated that effective, sustained control of elevated arterial pressure to a level below 140/90 mm Hg results in reduced cardiovascular morbidity and mortality. Over the past 4 decades antihypertensive drug therapy has evolved from a stepwise, but physiologically rational, selection of agents to specific programs tailored to individualized therapy for specific clinical situations. This evolution has taken place because of a greater understanding of the pathophysiology of hypertensive diseases, the development of new classes of antihypertensive agents that attack specific pressor mechanisms, and the ability to wed these concepts into a rational and specific therapeutic program. Thus, with the currently available spectrum of antihypertensive therapy, we are now able to select treatment for special patient populations utilizing a single agent and, therefore, we can protect the heart, brain and kidneys and maintain organ function without exacerbating associated diseases. These benefits are clear-cut and have resulted in many millions of patients becoming the beneficiaries of this transfer of careful, painstaking and purposeful investigative experiences into clinical practice.

Initial drug therapy for hypertensive patients with hyperlipidemia

Hypertension and hyperlipidemia are cardiovascular risk factors that commonly coexist. Studies have indicated that it is important to control both risk factors to achieve significant reductions in morbidity and mortality. Recent debate has focused upon whether traditional step I antihypertensive agents can substantially lower these risks because of their effects on plasma lipids. This debate continues to be unresolved. However, for the patient with elevated lipid levels, diuretics and beta-blockers may make the management of the lipid disorder more difficult. Therefore it may be desirable to select alternative step I antihypertensive agents that will not interfere with the therapy for hyperlipidemia. Alternative step I agents include alpha 1-blockers, ACE inhibitors, and calcium channel blockers. These agents either have no effect on plasma lipids or they improve the lipid profile. Generally, these drugs are well tolerated and provide good alternatives for patients with hyperlipidemias. The initial drug of choice can be chosen depending upon other patient variables such as age, race, or concomitant diseases.

Sustained-release diltiazem: duration of antihypertensive effect

The antihypertensive activity of a sustained-release preparation of diltiazem (given each 12 hours) was assessed in 96 patients with supine diastolic blood pressure (BP) between 95 and 110 mm Hg in a multicenter, randomized, double-blind, placebo run-in, parallel-group trial comparing optimally titrated doses of diltiazem and placebo. The aim was to assess the onset of action as well as the extent and variability of BP control of this formulation during the 12-hour interval. Diltiazem was titrated from 120 mg bid to 180 mg bid as necessary to lower BP. At baseline, on the first day of titration, and at the end of 8 weeks, BP was evaluated at 0, 1, 2, 3, 4, 5, 6, 8, 10, and 12 hours after dosing. The onset of action was within 2 hours, and the effect was maintained throughout the 12-hour period. Mean BP for the diltiazem group at baseline was 154/101 mm Hg. At week 8, BP was 148/93 mm Hg at hour "0" (P less than .02 and P = .0001 for systolic and diastolic BP vs. placebo), 139/84 mm Hg at the nadir at hour 5 (P = .0001), and 149/91 mm Hg at the end of the 12-hour period (P less than .02 and P = .0001 for systolic and diastolic BP). Diltiazem was significantly more effective than placebo (P = .0001) with 50% of patients controlled to a diastolic pressure of less than 90 mm Hg at 7 of the 10 evaluation points, including the evaluation point of 12 hours post-dose.(ABSTRACT TRUNCATED AT 250 WORDS)

New insights and new approaches for the treatment of essential hypertension: selection of therapy based on coronary heart disease risk factor analysis, hemodynamic profiles, quality of life, and subsets of hypertension

The pharmacologic therapy of mild primary hypertension (diastolic blood pressure less than 105 mm Hg) has effectively reduced hypertensive arteriolar end organ disease such as cerebrovascular accidents, congestive heart failure, and nephropathy, but there has been no convincing evidence that coronary heart disease (CHD) or its complications, acute myocardial infarction or angina, have been reduced. The risks of therapy with certain antihypertensive drugs may outweigh their treatment benefits as it relates to CHD. The optimal treatment strategy should be to reduce all CHD risk factors, reverse the hemodynamic abnormalities present by lowering the systemic vascular resistance (SVR), preserving cardiac output (CO) and perfusion, and to select the best antihypertensive drug for concomitant medical diseases or problems while maintaining a good quality of life. Antihypertensive drugs that have favorable or neutral effects on CHD risk factors include alpha blockers, calcium channel blockers, central alpha agonists, and angiotensin-converting enzyme inhibitors. On the other hand, diuretics and beta blockers without intrinsic sympathomimetic activity have unfavorable effects on many CHD risk factors. Baseline and serial evaluation of the effects of these drugs on serum lipids, lipid subfractions, glucose, uric acid, electrolytes, exercise tolerance, left ventricular hypertrophy, blood pressure, SVR, CO, perfusion, concomitant diseases, and side effects is necessary to evaluate overall cardiovascular risk.

A dose-response study of amlodipine in mild to moderate hypertension

The antihypertensive efficacy and suitability for once daily dosing of amlodipine, a new calcium antagonist, was studied in a series of 205 patients with mild to moderate hypertension. The study was conducted double-blind in 13 centres. The starting doses of amlodipine were 1.25, 2.5 and 5 mg, respectively, which were doubled after 4 weeks if normotension or a preset target blood pressure was not reached. Target blood pressure was reached in 25% of patients with placebo, 41% with 2.5 mg of amlodipine, 56% with 5 mg of amlodipine and 73% with 10 mg of amlodipine once daily. The drug was well tolerated at all dose levels and no changes occurred in heart rate, body weight or electrocardiogram during treatment. Amlodipine is a useful new calcium antagonist for the treatment of hypertension producing smooth, dose-dependent blood pressure reductions with convenient once daily dosing.

Effects of isradipine, a new calcium antagonist, versus hydrochlorothiazide on serum lipids and apolipoproteins in patients with systemic hypertension

The effect of isradipine versus hydrochlorothiazide on the lipid profile of 44 hypertensive patients was investigated in a double-blind, randomized, 2-center trial. Lipid profiles included total cholesterol, serum triglycerides, high density lipoprotein (HDL) cholesterol, HDL subclasses, (HDL2 and HDL3), low density lipoprotein cholesterol, very low density lipoprotein cholesterol, apolipoprotein A-1 and apolipoprotein B. Isradipine had no effect on the lipid profile in short- (4 and 10 week) or long-term (52 week) studies. Hydrochlorothiazide increased serum triglycerides in 11 of 13 patients by a mean of 8% for the group (p less than 0.05) in long-term (52 week) studies, and total cholesterol by a mean of 9 and 16%, respectively (p less than 0.01) in 2 of 13 patients, with no difference in other lipid or lipoprotein parameters in short- or long-term studies.

Hypertension and diabetes

Diabetes mellitus and hypertension are both common diseases, especially with an increasingly aged population. Hypertension accelerates the development of diabetic retinopathy, nephropathy, and peripheral vascular disease in the diabetic patient. Diabetes represents a type of premature aging and hypertension in the diabetic patient is characterized by many of the same pathophysiologic properties seen in the elderly hypertensive patient.

Diltiazem and captopril alone or in combination for treatment of mild to moderate systemic hypertension

The efficacy and safety of sustained-release diltiazem, 60 to 180 mg twice daily, was compared with that of captopril, 25 to 75 mg twice daily, alone and in combination, in 132 patients with mild to moderate essential hypertension (supine diastolic blood pressure [BP] 95 to 114 mm Hg). All patients received placebo for 4 to 6 weeks, followed by randomization to diltiazem or captopril during the double-blind monotherapy phase. Either study drug was titrated over 6 weeks to achieve a goal supine diastolic BP reduction of at least 10 mm Hg and a diastolic BP of less than 90 mm Hg. Patients achieving the goal BP reduction were maintained on monotherapy for an additional 8 weeks. Patients not achieving the treatment goal after 8 weeks with either drug alone received the other drug in combination, titrated to achieve goal BP response. Both drugs lowered BP significantly and, at the doses used, diltiazem had a greater effect on diastolic BP than did captopril. The mean changes from baseline at week 8 were -10.6 and -7.3 mm Hg, respectively, (p = 0.01). Goal BP was achieved in 38% of patients taking diltiazem monotherapy and in 34% of patients taking captopril monotherapy. There were no significant differences between diltiazem and captopril in diastolic or systolic BP reductions by race or age. The addition of alternate therapy for non-goal achievers at week 8 resulted in significant reductions in diastolic and systolic BP by week 16.(ABSTRACT TRUNCATED AT 250 WORDS)

Metabolic effects of antihypertensive therapy with a calcium antagonist

The effect of diuretics to increase serum glucose, low-density lipoprotein cholesterol and triglycerides, as well as the adverse changes in triglycerides and high-density lipoprotein cholesterol produced by nonselective beta blockers, have been largely ignored in the treatment of hypertension. However, a number of trials have shown that reductions in serum lipids can alter cardiovascular mortality. Calcium antagonists have become major drugs in the treatment of hypertension, and some data suggest that calcium antagonists may increase serum glucose levels. Significantly less data on lipid effects have been published. Lipid and glucose effects were examined in an 8-week antihypertensive study using a sustained-release preparation of diltiazem titrated from 240 to 360 mg/day in a twice-daily regimen in a randomized, double-blind, placebo-controlled parallel trial in 96 patients. Average supine blood pressure at week 8 was 156/98 mm Hg, standing blood pressure with placebo 152/100 mm Hg, and with diltiazem 147/91 and 144/93 mm Hg. There were no statistically significant changes in serum lipids or glucose in the diltiazem or placebo group or between the groups. Mean values (mg/dl) at baseline and week 8 in the diltiazem group were, respectively, for cholesterol 215 and 218, high-density lipoprotein cholesterol 50 and 51, low-density lipoprotein cholesterol 128 and 133, triglycerides 169 and 175, and glucose 113 and 110. Thus, this large and placebo-controlled study shows that diltiazem is among the antihypertensives with no adverse long-term lipid or glucose effects.

Calcium metabolism, calcium-channel blocking agents, and hypertension management

Increasing evidence has suggested that a disturbance of cellular calcium metabolism may have a role in initiating and maintaining elevated systemic vascular resistance in essential hypertension. Controversy exists over whether calcium can alleviate or exacerbate the hypertensive process, and diversity of calcium metabolism in hypertensive patients has been proposed. Calcium-channel blocking agents are potent vasodilators capable of correcting the elevated systemic vascular resistance. Clinical studies have shown that these drugs have antihypertensive efficacy comparable to established agents. The elderly, blacks, and patients with low renin activity respond well to calcium-channel blockers. These drugs may also offer potential advantages over established antihypertensive agents in patients with other coexisting diseases. Sustained release formulations have been developed, and initial experience with long-term efficacy and tolerability is encouraging. The calcium-channel blockers may become first-line therapy for treatment of hypertension in selected patients.

Nonselective beta-receptor blocker effect on high density lipoprotein cholesterol after chronic exercise

High density lipoprotein (HDL) cholesterol changes were followed in 45 men with coronary heart disease who underwent 12 weeks of monitored aerobic exercise. Twenty-five patients who were taking a nonselective beta-receptor blocking drug (Group 1) did not demonstrate a significant change in HDL cholesterol after exercise (mean difference 2.8 +/- 11.5 mg/dl), whereas patients who had not received a beta-blocking drug for greater than or equal to 3 months (Group 2) showed a significant increase (mean difference 8.4 +/- 5.5 mg/dl; p less than 0.05). However, for those patients in each group who had an initial HDL cholesterol level less than 35 mg/dl before exercise, there was a significant increase in HDL cholesterol levels (mean difference 8 +/- 6.9 mg/dl [p less than 0.02] and 11 +/- 3 mg/dl [p less than 0.001] for Group 1 and Group 2, respectively) and a significant decrease in the low density lipoprotein (LDL/HDL cholesterol ratio (mean difference -1.2 +/- 1.6 [p less than 0.05] and -0.9 +/- 0.57 [p less than 0.001], respectively). Patients in both groups who started exercise with an HDL cholesterol level greater than 35 mg/dl did not show a significant change after exercise. Patients in Groups 1 and 2 achieved similar levels of exercise training after 12 weeks and were closely matched in age, medications, alcohol intake and smoking. The results indicate that among high risk patients (with an abnormally low HDL cholesterol level) exercise training can induce an augmentation of HDL cholesterol in those receiving a beta-blocking drug similar to that of patients not receiving such a drug.