Elevation of serum lipid levels during diuretic therapy of hypertension

Clinical significance of dynamic variation of low cholesterol and its prognostic value in patients with pyogenic liver abscesses: a retrospective study

BACKGROUND

Serum lipids variations are closely related to the sepsis progression; however, their value for patients with pyogenic liver abscesses (PLA) has rarely been studied. We investigated the serum lipid level variations in patients with PLA and its predictive value to the disease.

METHODS

The study included 328 patients with PLA hospitalized in the First Affiliated Hospital of Nanjing Medical University from January 2017 to December 2021; 35 (10.67%) in the severe group (SG) and 293 (89.33%) in the non-severe group (nSG). Their clinical records were analyzed retrospectively, and dynamic curves were drawn to clarify the changes in different indicators during the course of the disease.

RESULTS

High-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and lipoprotein(a) (Lp(a)) in the SG were significantly lower than those in nSG (P < 0.001). Total cholesterol (TC) at baseline (OR = 0.184, P < 0.001) was an independent risk factor for severe patients and had the highest predictive value, with an area under the curve of 0.859 and a cut-off value of 2.70 mmol/L (sensitivity = 94.3%, specificity = 63.5%). For patients who met the criteria for drainage surgery, TC, HDL-C and LDL-C levels continued to decrease with antibiotic therapy alone before drainage and began to increase after the surgery.

CONCLUSIONS

Low TC level on admission is an independent risk factor for the progression of severe illness in PLA patients, with the highest predictive value surpassing other routine clinical indices. Abscess drainage should be performed as soon as possible for patients whose TC continues to decline after medical treatment.

Associations of systemic health and medication use with the enlargement rate of geographic atrophy in age-related macular degeneration

BACKGROUND

The associations of geographic atrophy (GA) progression with systemic health status and medication use are unclear.

METHODS

We manually delineated GA in 318 eyes in the Age-Related Eye Disease Study. We calculated GA perimeter-adjusted growth rate as the ratio between GA area growth rate and mean GA perimeter between the first and last visit for each eye (mean follow-up=5.3 years). Patients' history of systemic health and medications was collected through questionnaires administered at study enrolment. We evaluated the associations between GA perimeter-adjusted growth rate and 27 systemic health factors using univariable and multivariable linear mixed-effects regression models.

RESULTS

In the univariable model, GA perimeter-adjusted growth rate was associated with GA in the fellow eye at any visit (p=0.002), hypertension history (p=0.03), cholesterol-lowering medication use (p<0.001), beta-blocker use (p=0.02), diuretic use (p<0.001) and thyroid hormone use (p=0.03). Among the six factors, GA in the fellow eye at any visit (p=0.008), cholesterol-lowering medication use (p=0.002), and diuretic use (p<0.001) were independently associated with higher GA perimeter-adjusted growth rate in the multivariable model. GA perimeter-adjusted growth rate was 51.1% higher in patients with versus without cholesterol-lowering medication use history and was 37.8% higher in patients with versus without diuretic use history.

CONCLUSIONS

GA growth rate may be associated with the fellow eye status, cholesterol-lowering medication use, and diuretic use. These possible associations do not infer causal relationships, and future prospective studies are required to investigate the relationships further.

Hypertension, antihypertensive medications use and risk of age-related macular degeneration in California Teachers Cohort

Sustained and inadequately controlled hypertension can promote the development of age-related macular degeneration (AMD) through multiple biologic pathways. Epidemiologic studies of high blood pressure, antihypertensive therapies, and the risk of AMD thus far have been inconclusive. However, few studies evaluated risks according to the use of different classes of antihypertensive drugs or took combinations of use into account. We performed a prospective cohort study by linking the California Teachers Study (CTS) cohort (N = 88 481) to statewide hospital discharge records up to December 31, 2012. History of high blood pressure, regular use of antihypertensive medications, and comprehensive risk factor information was collected via self-administered questionnaires at baseline in 1995-1996, and information on specific classes of antihypertensive drugs was provided by a subsample of CTS participants who completed a follow-up questionnaire in 2000. We identified 1762 female teachers with AMD during 14.8 years of follow-up on average. Applying Cox proportional hazard regression, we estimated increased risks of AMD among women treated for hypertension at baseline (HR = 1.15, 95% CI: 1.03, 1.30); the magnitude of the association increased with longer duration of antihypertensive treatment. In the subsample with more specific information on type of medication use, we estimated a 45% increased risk of AMD among women receiving diuretics as monotherapy compared to women with medications more potent than diuretics (HR = 1.45, 95% CI 1.10, 1.90). In women treated with a combination of antihypertensive drugs, we observed no increased risk of AMD for any individual class of drugs.

Effect of furosemide on the lipid abnormalities in chronic renal failure

The effect of furosemide on the lipoprotein profile and the activities of postherapin plasma lipases were studied in 12 patients with chronic renal failure. The concentrations of serum total, VLDL and LDL triglycerides were significantly higher and the concentration of HDL triglyceride was significantly lower in the patients with renal failure than in healthy controls. HDL cholesterol was significantly lower in the patients than in the controls. The activity of postherapin lipoprotein lipase was significantly lower in the patients than in the controls. The introduction of furosemide induced a significant increase in the concentrations of VLDL cholesterol and VLDL triglyceride. These changes were reversed when the drug treatment was discontinued. Postherapin lipase activities were not further altered by furosemide.

Antihypertensive, haemodynamic and metabolic effects of nifedipine slow-release tablets in elderly patients

In a double-blind, cross-over study for 8 weeks, including 10 non-hospitalized elderly hypertensives (average age 73.2 years), WHO stage I-II, the antihypertensive effect of nifedipine slow-release tablets, 20 mg twice daily, was compared with placebo. Nifedipine reduced supine and standing blood pressure values significantly, and no signs of orthostatic hypotension were noted. An initial increment in heart rate was found after 1 week with a subsequent fall towards control values after 8 weeks of nifedipine administration. Heart rate pressure product in the supine position was reduced, and this reduction became statistically significant at the 8th week. Cardiac output measured non-invasively in 8 patients after 6-8 weeks' nifedipine therapy, using an Irex echocardiograph, was on an average 34% higher than in the placebo period (p less than 0.05). Serum electrolytes, cholesterol, HDL cholesterol, blood glucose and renal function were not affected by the drug. Side-effects were few and mild. It is concluded that nifedipine is a potent antihypertensive agent which may represent an attractive first choice alternative in the treatment of elderly hypertensive patients.

An open-label, randomized, controlled, 4-week comparative clinical trial of barnidipine hydrochloride, a calcium-channel blocker, and benazepril, an angiotensin-converting enzyme inhibitor, in Chinese patients with renal parenchymal hypertension

This study compared barnidipine, a calcium-channel blocker, and benazepril, an angiotensin-converting enzyme inhibitor, in 85 Chinese patients with renal parenchymal hypertension (diastolic blood pressure range 95 - 110 mmHg). Patients were randomly assigned to receive either 10 mg barnidipine or 10 mg benazepril orally daily for 4 weeks. In patients with diastolic blood pressure > 90 mmHg after 2 weeks of treatment, the dose of barnidipine or benazepril was increased by 5 or 10 mg, respectively. Both the barnidipine-treated group (n = 43) and the benazepril-treated group (n = 42) showed significant mean reductions from baseline in sitting systolic and diastolic blood pressures. The decrease in diastolic blood pressure with benazepril was significantly greater than with barnidipine treatment. Sitting heart rate was not changed by either drug. There was no significant difference in adverse events between the two groups. Barnidipine is similar to benazepril for the treatment of renal parenchymal hypertension.

Prognostic impact of systolic hypertension on asymptomatic patients with chronic severe aortic regurgitation and initially normal left ventricular performance at rest

The influence of systolic hypertension (SH) on the natural history of chronic aortic regurgitation (AR) and the clinical effect of antihypertensive medication on patients who have hypertension and AR are incompletely defined. Therefore, we reviewed the clinical course of 80 unoperated patients who were entered prospectively into an assessment of natural history of AR and its predictors and were asymptomatic with normal left ventricular ejection fraction (LVEF) at rest at study entry; 30 of 80 patients had SH (systolic blood pressure >140 mm Hg); 20 of 80 patients (16 had SH) used antihypertensive drugs for the long term (not mandated by protocol). During an average 7.2-year event-free follow-up, 24 patients developed symptoms alone (n = 14), subnormal LVEF with or without symptoms (n = 8), or died suddenly (n = 2). SH tripled the average annual risk of cardiac events (8.47% vs 2.85%, p = 0.004). The effect of systolic blood pressure was independent of age, gender, diastolic blood pressure, LV diastolic dimension, fractional shortening, and LVEF at rest (p = 0.004 to <0.008). However, positive prognostic interactions existed between systolic blood pressure and pulse pressure (p <0.001), LVEF during exercise (p <0.001), change in LVEF from rest to exercise (p <0.001), and the contractility index (p <0.02). Among patients who had SH, antihypertensive therapy predicted increased event risk (average annual risk 15.46% vs 3.98%, p <0.02) and remained predictive when analysis was adjusted for potentially confounding subgroup variations at study entry (p <0.03, all models). In conclusion, SH portends poor clinical outcome in chronic severe AR. As a group, antihypertensive drugs do not mitigate outcome, although the effect of individual drugs is uncertain and at least some may be deleterious. The theoretically based practice of giving antihypertensive drugs to patients who have AR requires reexamination.

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.

Serum potassium and cardiovascular mortality

BACKGROUND

The impact of serum potassium on mortality is inadequately defined.

OBJECTIVE

To determine the association of serum potassium with mortality.

METHODS

We analyzed NHANES I Epidemiological Follow-up Study data from 1974-1992. Of 2,992 subjects with baseline serum potassium, 156 were excluded because their vital status was not known. A total of 2,836 subjects with serum potassium within 2.7-5.4 mmol/L were studied. All-cause and cardiovascular mortality were assessed controlling for sociodemographic status, smoking, medical history, and clinical characteristics.

RESULTS

At baseline, mean age was 46.6 years, and mean serum potassium was 4.07 mmol/L. Subjects were stratified into three groups by mean +/-1 standard deviation of serum potassium: low, 2.7-3.7 mmol/L (N = 477); middle, 3.8-4.4 mmol/L (N = 1,982); and high, 4.5-5.4 mmol/L (N = 377). The cardiovascular mortality rate per 1,000 person-years adjusted for age, gender, and race for the high serum potassium group (8.1) was significantly higher than the middle (5.3) and low (6.5) serum potassium groups. Further analysis, controlling for age, gender, race, smoking status, cholesterol, and history of diabetes, renal disease, and cardiovascular disease, revealed that the increased cardiovascular mortality among subjects with moderately increased serum potassium was most prominent in those reporting use of diuretics (hazard ratio, 2.65; 95% confidence interval [95% CI], 1.20 to 5.85) and those with abnormal renal function (hazard ratio, 1.89; 95% CI, 1.05 to 3.41).

CONCLUSION

In this general population sample with mostly normal serum potassium, higher serum potassium was independently associated with increased cardiovascular mortality.

Antihypertensive effect of roselle (Hibiscus sabdariffa) calyx infusion in spontaneously hypertensive rats and a comparison of its toxicity with that in Wistar rats

The LD(50) of roselle calyx extract and its effect on blood pressure were determined. The LD(50) was found to be above 5000 mg kg(-1). Roselle calyx infusion was found to lower significantly (p<0.05) both systolic and diastolic pressure in spontaneously hypertensive and normotensive Wistar-Kyoto rats at tested doses of 500 and 1000 mg kg(-1) body weight. The reduction in blood pressure in both groups was positively correlated with weight. Continuous consumption of the infusion at 1000 mg kg(-1) was discovered to lead to sudden death in spontaneously hypertensive rats but not in Wistar-Kyoto rats. Water intake was not significantly different (p>0.05) in the control groups of the two strains of rats used, neither was there a significant difference in their urine output. The water intake in the treated spontaneously hypertensive and normotensive rats was not different from the corresponding control groups. However the urine output of the treated spontaneously hypertensive rats was significantly higher. A significant decrease in serum creatinine, cholesterol, and glucose in the treated rats compared with the control as well as a significant increase in serum uric acid was observed. The serum proteins (albumin and total protein) in the treated rats when compared with the control groups was not changed significantly.

Lessons from hypertension trials

Hypertension is a well-established risk factor for stroke, myocardial infarction (MI), and premature cardiovascular death. Even mild elevations of blood pressure (i.e., diastolic blood pressure >90 and <110 mm Hg) yield increased risk. In fact, mild-to-moderate hypertension is more common than severe hypertension and accounts for a greater proportion of the deaths and serious nonfatal vascular events. The treatment goal is to make optimal use of antihypertensive drug therapy while encouraging patients to implement lifestyle changes such as weight loss, sodium restriction, decreased alcohol intake, and increased exercise. Pharmacologic therapy of mild-to-moderate hypertension can significantly reduce the incidence of stroke, MI, coronary artery disease, vascular mortality, and total mortality. Beta blockers and diuretics should continue to be used as first-line therapy until there is direct and reliable evidence from large-scale randomized trials with clinical endpoints for newer agents such as calcium antagonists and angiotensin-converting enzyme inhibitors.

Antihypertensive treatment and serum cholesterol: results of population-based surveys in the German Cardiovascular Prevention Study

We analyzed the data from three cross-sectional, population-based surveys in West Germany to evaluate the effect of antihypertensive drug therapy on the level of serum cholesterol in German residents (18,344 males; 19,137 females) aged 25-69 years, after excluding persons with missing values (N = 5529) for any study variable. The data were obtained from the national and regional health surveys that were conducted during the years 1984-1992, within the framework of the German Cardiovascular Prevention Study (GCP). The response rates were between 66.0% and 71.4% for the national surveys and between 65.9% and 83.3% for the regional surveys. Blood-pressure and non-fasting cholesterol measurements were carried out under strictly standardized conditions. Multiple linear regression analysis was used to compare the age-adjusted mean value and prevalence for each of the following study variables: total serum cholesterol, HDL-cholesterol, non-HDL cholesterol, and the ratio of HDL cholesterol/total cholesterol for users and non-users of antihypertensive medications. Antihypertensive medications were reportedly taken during the seven days preceding the survey examination by 7.8% of all males and 10.4% of all females. The beta-blocker type of medication was prescribed most frequently for lowering high blood pressure. In both genders, the strongest age-adjusted effect of an increase in cholesterol level was found for beta-blockers. The difference in the age-adjusted means for non-HDL cholesterol values between users and non-users of beta-blockers was 9.2 mg/dL (p < 0.001) in males and 9.0 mg/dL (p < 0.001) in females. Regression analysis carried out to control for several potential confounders confirmed the results. The findings suggest that mass treatment of hypertension with beta-blockers may be associated with reductions in benefit because of an increase in non-HDL and a decrease in HDL cholesterol levels.

Interaction between Potassium-Depleting Diuretics and Lovastatin in Hypercholesterolemic Ambulatory Care Patients

Objective:

To evaluate the potential impact of potassium-depleting diuretics on the efficacy of lovastatin.

Design:

A retrospective study of ambulatory patients taking lovastatin and thiazide or loop diuretics was conducted.

Setting:

Ambulatory care patients with coexisting hypercholesterolemia and hypertension from a Veterans Affairs Medical Center.

Participants:

A total of 32 patients were studied, 13 of whom had been taking lovastatin before diuretics were added. Another 19 patients had been receiving diuretics before lovastatin was initiated. The changes in their total cholesterol from baseline were recorded and analyzed.

Main Outcome Measures:

In all the patients taking lovastatin and diuretics concurrently, total cholesterol concentrations dropped initially, followed by a rise despite continuation of therapy with lovastatin. The reason for this initial drop in total cholesterol following 1 month of concurrent therapy is the subject of further investigation in a prospective study.

Results:

Regardless of the order of administration of the lipid-lowering and antihypertensive drugs, serum cholesterol rose 20% from its nadir.

Conclusions:

Patients taking potassium-depleting diuretics and a hepatic hydroxymethylglutaryl-coenzyme A reductase enzyme inhibitor (lovastatin) concurrently do not seem to benefit substantially from the lipid-lowering effect of lovastatin, probably because of a functional antagonism of the lipid-lowering effect of lovastatin by potassium-depleting diuretics.

Effects of lisinopril and bisoprolol on lipoprotein metabolism in patients with mild-to-moderate essential hypertension

The short- and long-term effects of the angiotensin-converting enzyme inhibitor lisinopril and the cardioselective beta-blocker bisoprolol on serum lipids, lipoproteins, apolipoproteins, and lipoprotein(a) (Lp[a]) levels were investigated in patients with mild-to-moderate essential hypertension. Fifty-two patients completed the 12-month, randomized, multicenter trial. After administration of lisinopril (10 to 20 mg/d; n = 24) and bisoprolol (2.5 to 10 mg/d; n = 28), systolic and diastolic blood pressures decreased significantly (P < 0.01) from baseline in both groups at 3, 6, and 12 months. The reduction in diastolic blood pressure was significantly (P < 0.05) greater in the lisinopril group than in the bisoprolol group only at 6 months. Heart rates dropped significantly in the bisoprolol group but not in the lisinopril group. No significant changes in lipids, lipoproteins, apolipoproteins, or Lp(a) levels were observed with either drug at 3, 6, or 12 months, and no significant differences were noted between the two drugs for these parameters. We conclude that lisinopril and bisoprolol are effective as antihypertensive drugs without adverse metabolic effects after short- and long-term treatment in patients with mild-to-moderate essential hypertension.

A comparison of the effects of low- and conventional-dose thiazide diuretic on insulin action in hypertensive patients with NIDDM

In conventional doses, thiazide diuretics impair glucose tolerance and decrease insulin sensitivity, making them an unpopular choice for treating diabetic patients with hypertension. However, use of low-dose thiazide diuretics may avoid the adverse metabolic effects seen with conventional doses. In a double-blind, randomised crossover study we assessed peripheral and hepatic insulin action in 13 hypertensive non-insulin-dependent diabetic patients after a 6-week placebo run-in and following two 12-week treatment periods with either low (1.25 mg) or conventional (5.0mg) dose bendrofluazide. There were no differences between doses in their effects on systolic and diastolic blood pressure. Bendrofluazide 1.25 mg had significantly less effect on serum potassium, uric acid, fasting glucose and HbA1C concentrations than the 5.00 mg dose. Exogenous glucose infusion rates required to maintain euglycaemia were significantly different between doses (p < 0.05) with conventional-dose bendrofluazide worsening peripheral insulin resistance compared to baseline (23.8 +/- 2.9 vs 27.3 +/- 3.5 mumol.kg-1.min-1, p < 0.05) and low-dose bendrofluazide producing no change compared to baseline (26.8 +/- 3.6 vs 27.3 +/- 3.5 mumol.kg-1.min-1, p = NS). Postabsorptive endogenous glucose production was higher on treatment with bendrofluazide 5.0 mg compared to 1.25 mg (11.7 +/- 0.5 vs 10.2 +/- 0.3 mumol.kg-1.min-1, p < 0.05) and suppressed to a lesser extent following insulin (4.0 +/- 0.7 vs 2.0 +/- 0.4 mumol.kg-1.min-1, p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Metabolic adverse reactions to diuretics. Clinical relevance to elderly patients

There is a wide variety of diuretic-induced metabolic abnormalities of unequal severity. Renal failure can be caused by excessive sodium loss, or by certain drug combinations comprising, for instance, a nonsteroidal anti-inflammatory drug (NSAID) or an ACE inhibitor. Hyponatraemia is uncommon. It is encountered with thiazides, especially among women. A sodium level less than 120 mmol/L may result in neurological complications. Hypokalaemia is frequent and might increase the risk of cardiac arrhythmia. Hyperkalaemia induced by potassium-sparing diuretics is often combined with another contributive cause. Glucidic, lipidic and uric acid abnormalities are common, but their clinical effects are slight. They do not seem to worsen cardiovascular risks among elderly patients. Nevertheless, prescribing diuretics for elderly patients requires special precautions. Reducing the diuretic dose, as is now recommended for treating hypertension, seems to lessen adverse effects, and despite all the adverse reactions just mentioned, it has been proven that diuretics are beneficial in many diseases.

Effects of low dose versus conventional dose thiazide diuretic on insulin action in essential hypertension

OBJECTIVE

To see whether low dose thiazide diuretics given to patients with essential hypertension might avoid the adverse metabolic consequences seen with conventional doses.

DESIGN

Double blind randomised crossover study of two 12 week treatment periods with either low dose (1.25 mg) or conventional dose (5.0 mg) bendrofluazide given after a six week placebo run in period.

SETTING

Outpatient clinics serving the greater Belfast area.

SUBJECTS

16 white non-diabetic patients (9 male) under 65 with essential hypertension recruited from general practices within the greater Belfast area.

MAIN OUTCOME MEASURES

Systolic and diastolic blood pressure and peripheral and hepatic insulin action.

RESULTS

One man failed to complete the study. There were no differences between doses in their effects on systolic and diastolic blood pressure. Bendrofluazide 1.25 mg had substantially less effect on serum potassium concentration than the 5.0 mg dose. There were no intertreatment differences in fasting glucose, insulin, cholesterol, and triglyceride concentrations. Bendrofluazide 5.0 mg significantly increased postabsorptive endogenous glucose production compared with baseline (mean 10.9 (SD 1.2) v 10.0 (0.8) mumol/kg/min), whereas bendrofluazide 1.25 mg did not. Postabsorptive endogenous glucose production was significantly higher with bendrofluazide 5.0 mg compared with 1.25 mg (10.9 (1.2) v 9.9 (0.8) mumol/kg/min) but was suppressed to a similar extent after insulin (bendrofluazide 5.0 mg 2.8 (1.5) mumol/kg/min v bendrofluazide 1.25 mg 2.2 (1.5) mumol/kg/min). Exogenous glucose infusion rates required to maintain euglycaemia were not significantly different between doses and were similar to baseline.

CONCLUSIONS

Bendrofluazide 1.25 mg is as effective as conventional doses but has less adverse metabolic effect. In contrast with conventional doses, low dose bendrofluazide has no effect on hepatic insulin action. There is no difference between low and conventional doses of bendrofluazide in their effect on peripheral insulin sensitivity.

Development of metaphylaxis in calcium urolithiasis: a restriction of conventional drug therapy

Between 1978 and 1992 (mean 9.2 years), metaphylaxis was introduced to 110 patients originally hospitalized for recurrent urinary calcium stones (mostly bilateral or multiple). Patients with hyperparathyroidism or with sponge kidney were excluded from the study. Until 1984, the condition had been treated mostly using conventional drug metaphylaxis (thiazides and allopurinol in 75% and 57%, respectively). After that year, there was a gradual decrease in the number of patients treated with thiazides (to 15%) and allopurinol (to 10%). This was associated with a steep rise in the proportion of patients treated with inhibitors (magnesium to 36% and citrates to 30%), or exclusively with non-medicamentous therapy (to 31%). These fundamental changes in approach have not reduced the effectiveness of metaphylaxis, and recurrence rates in individual years have not changed significantly either. Metaphylaxis was successful in 105 patients (95%) and the rate of recurrence has declined from 0.9 to 0.08 stones per year. The restriction of conventional drug metaphylaxis has entailed a marked decrease in the incidence of side effects of therapy and, consequently, a reduced need for follow-up tests and outpatient follow-up.

The effects of various antihypertensive agents on cardiovascular risk factors in patients with renal failure

Systemic cardiovascular diseases are the most important cause of morbidity and mortality among patients with chronic renal failure. Hypertension, lipid-profile abnormalities, glucose intolerance, and left ventricular hypertrophy are found in most patients with chronic renal failure and are responsible for the increased incidence of atherosclerosis. Hypertension is the risk factor most susceptible to treatment, but consideration must be given in selecting an antihypertensive agent not only to its effect on blood pressure but to its effects on the other risk factors. Improper selection could impair the long-term benefit of good blood pressure control by increasing the severity of the other cardiovascular risk factors and eventually worsening the prognosis of the chronic renal failure. The remaining renal function in patients not yet in end-stage renal failure deserves special consideration; an adequate antihypertensive regimen could potentially delay the need for dialysis.

The treatment of elderly hypertensive patients

Treatment of hypertension in the elderly has hitherto been considered to be potentially dangerous. Three recent studies have clearly shown that in selected elderly hypertensives, blood pressure reduction very effectively reduces cardiovascular complications without causing unacceptable adverse effects. The impact on non-fatal stroke was most striking although a reduction in coronary events was also achieved. Thiazide diuretics were used in all three trials, and beta-blockers were used in two. Thiazide diuretics had a major beneficial effect. In this review the applicability of these results to the whole unselected population of elderly hypertensives is considered, and the choice of therapy in different subgroups of patients discussed.

The place of diuretics in the treatment of hypertension: a historical review of classical experience over 30 years

Thiazide diuretics have been the mainstay of antihypertensive therapy for over 30 years. Their precise mechanism of antihypertensive action is still incompletely understood. They reduce arterial pressure initially through a fall in plasma volume and cardiac output. However, with chronic administration cardiac output tends to return toward pretreatment levels, suggesting that the long-term pressure reduction is mediated through a reduction in vascular resistance. Although multiple lines of evidence suggest that salt and water loss is an essential part of the mechanism, at least in some cases an indirect vasodilator effect may play a role as well. The antihypertensive efficacy of diuretics is proven; they are at least as effective as other classes of antihypertensive drugs. They have been shown to protect against stroke, but not against mortality from myocardial infarction. There is some concern about the metabolic side effects, such as hypokalemia, hyperglycemia, and hyperlipidemia. In order to minimize these side effects the lowest effective dose should be used. Diuretics are likely to remain first-line antihypertensive agents, but they should be considered as one of several possible choices for the initial therapy among other classes, such as beta-blockers, ACE inhibitors, or calcium entry blockers.

Doxazosin and captopril in mildly hypercholesterolemic hypertensive patients. The Doxazosin-Captopril in Hypercholesterolemic Hypertensives Study

The evidence linking hypertension and hypercholesterolemia is strong and has fueled research into possible adverse effects of some antihypertensive agents on serum lipid profile. This multicenter, open, parallel study compares the effects of doxazosin and captopril on blood pressure, serum lipid levels, and quality of life in 224 hypercholesterolemic hypertensive patients. Blood pressure was significantly reduced in both treatment groups (p < 0.001) and was normalized (standing diastolic pressure < or = 90 mm Hg) in 73% of the doxazosin patients and 67% of the captopril group. Serum total cholesterol level was favorably reduced by both doxazosin (from 238 to 223 mg/dl, p < 0.001) and captopril (from 245 to 233 mg/dl, p < 0.001), whereas high density lipoprotein cholesterol concentration increased only in the doxazosin group (from 33 to 36 mg/dl, p < 0.001). The calculated 10-year risk for the development of coronary heart disease was reduced significantly (p < 0.001) by 28% in the doxazosin group and by 19% in the captopril group. The quality of life evaluation showed beneficial changes in both treatment groups. As a result of proven antihypertensive efficacy and a lack of unfavorable effects on lipid parameters and health status measures, these findings support the use of both doxazosin and captopril as agents of first choice in the treatment of hypertensive patients with associated lipid abnormalities.

Adverse effects of diuretics

Analysis of the available evidence indicates that diuretics do not increase coronary heart disease morbidity and mortality. The multiclinic trials supporting the cardiotoxicity hypothesis are few in number and flawed in design. The majority of the trials, including the well designed trials, indicate no excess of coronary heart disease (CHD) events in diuretic-treated patients compared with those given other drugs or placebo. Recent studies indicate no increase in cardiac arrhythmias after diuretic treatment. Also, although depletion of intracellular potassium and magnesium occurs in patients with congestive heart failure even without diuretics, intracellular concentration of these ions is not significantly reduced by diuretics in patients with uncomplicated hypertension. Modest elevations of serum cholesterol may occur during the first 6 to 12 months of treatment with thiazide diuretics. However, after this time these elevations fall to or below the pretreatment level. The fall may be greater in patients receiving other drugs but the differences are small and their clinical significance is questionable. The incidences of hyperglycaemia and diabetes were only minimally increased in long term clinical trials while the importance of hyperinsulinism and insulin resistance in causing CHD remains unproven in patients. Thiazides remain, therefore, a safe and effective treatment for patients with hypertension.

Diuretic induced long term hemodynamic changes in hypertension. A retrospective study in a MRFIT clinical center

Retrospective analysis of hemodynamic factors was performed on hypertensive participants of our Multiple Risk Factor Intervention Trial (MRFIT) center to determine whether these may have a role in the higher mortality in a subgroup of special intervention (SI) participants with minor baseline electrocardiographic abnormalities. Stroke volume was estimated by a formula [SV = K(LVETxPP)x(1 + LVET/DP) where the K factor was determined using a separate group of individuals undergoing cardiac catheterization. The Pearson correlation between the two methods (dye dilution and above formula) was 0.7744 with a 95% confidence interval of 0.57-0.89 for the true correlation. In 222 SI and 186 usual care (UC) participants with no differences in stroke volume index (SVI) and cardiac output index (CI) at baseline, SVI and CI were systematically lower during the entire period of treatment in SI receiving higher average doses of thiazide diuretics. There was a moderate increase of SVI and CI in SI participants toward baseline after hydrochlorothiazide was replaced by other antihypertensive medication in the fourth year of the trial. We conclude that the lower SVI and CI could have been a contributing factor in the higher mortality in the SI group with ECG abnormalities resulting in decreased coronary flow reserve under stress conditions in these participants with probably pre-existing asymptomatic coronary artery disease.

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.

Lipid profile studies in long term thiazide treated hypertensives

Serum cholesterol and its subfractions were estimated in 23 patients on thiazide diuretics, for treatment of mild hypertension, for at least 30 months. The results were compared with those obtained in a matched set of 25 untreated mild hypertensives. It was found that while there was no difference in the level of total cholesterol, the LDL-cholesterol was significantly lower and HDL-cholesterol significantly higher in the treated group. It was also found that the total:LDL-cholesterol ratio was more in the treated group and the total:HDL-cholesterol ratio was less in the treated group. These findings suggest that coronary risk attributable to cholesterol and its subfractions does not seem to operate in long term thiazide treated patients.

Hydrochlorothiazide versus spironolactone: long-term metabolic modifications in patients with essential hypertension

The metabolic side effects of thiazide diuretics are believed to be responsible for the failure of thiazide diuretics to reduce cardiovascular morbidity in patients with hypertension. However, the decrease in the incidence of osteoporotic fractures that are associated with thiazide administration may be relevant in elderly patients with arterial hypertension. Spironolactone (SP) appears not to influence the metabolic risk profile of the patient with hypertension, and no studies have examined its effect on calcium metabolism. Therefore, in 22 patients with mild to moderate essential hypertension, the authors performed a parallel, randomized, double-blind, placebo-controlled study that compared the effects on serum urate and lipid, potassium, magnesium, and calcium metabolism of hydrochlorothiazide (HC) (mean [+/- SD] dose, 72 +/- 26 mg/d) and SP (144 +/- 53 mg/d) during a 52-week period. As compared with placebo, HC significantly increased serum urate and total cholesterol concentrations, and decreased serum potassium levels. SP did not affect serum urate or cholesterol levels but increased serum potassium concentrations. Neither diuretic significantly modified magnesium metabolism. Little changes were seen in serum calcium levels during HC or SP treatment, whereas urinary calcium excretion was significantly decreased by HC (mean decrease, 45%; P less than .01) or SP (40%; P less than .01). The authors conclude that SP, in addition to its potassium-sparing properties, has a calcium-sparing effect that may be beneficial for patients in whom reduction of urinary calcium excretion has a therapeutic value.

Resolved and unresolved issues in the prevention and treatment of coronary artery disease: a workshop consensus statement

Advances in cardiovascular research during the past two decades have resulted in an improved understanding of the chain of events that lead to end-stage coronary artery disease. These developments have been paralleled by therapeutic advances that now make it possible to intervene at virtually every stage in the development of advanced cardiac disease, from asymptomatic persons at risk of developing coronary atherosclerosis to patients with end-stage heart failure. By interrupting this chain of events, perhaps at multiple sites, it may be possible to prevent or slow the development of symptomatic heart disease and hopefully prolong life. Many opportunities exist for obtaining further information regarding the underlying pathophysiology, the fundamental mechanisms of action of interventions designed to prevent and/or treat the development of myocardial ischemia and cardiac failure and for effecting favorably the natural history of various forms of heart disease.

A comparison of the anti-hypertensive effectiveness of two triameterene/hydrochlorothiazide combinations: Maxzide versus Dyazide

The hydrochlorothiazide component of Maxzide (Lederle Laboratories, Pearl River, NY) has been shown to be more bioavailable than the hydrochlorothiazide component of Dyazide (Smith, Kline and French Laboratories, Philadelphia, PA). The authors compared the antihypertensive effectiveness of a half-tablet of Maxzide (25 mg of hydrochlorothiazide and 37.5 mg of triamterene) to one capsule of Dyazide (25 mg of hydrochlorothiazide and 50 mg of triamterene) to determine if the difference in bioavailability would be reflected in differences in blood pressure control and metabolic changes. Thirty patients were studied in a randomized open-label crossover design study. There was a significant reduction in systolic blood pressure for both treatments although there was no difference in blood pressures at any time during the study between the two agents. There were no statistically significant differences between Maxzide and Dyazide in terms of metabolic changes for potassium, magnesium, glucose, cholesterol, triglycerides, uric acid, or calcium. Although the hydrochlorothiazide component of Maxzide is more bioavailable than that of Dyazide this did not translate into enhanced hypotensive efficacy.

Dietary sodium restriction: adverse effect on plasma lipids

In order to examine the effect of dietary sodium intake on plasma lipids, 15 healthy male volunteers were given a low-salt diet (20 mmol/day) for 3 weeks, adding either placebo, sodium chloride (200 mmol/day), or a non-chloride sodium salt (sodium citrate, 200 mmol Na/day) for one week each, in a single-blind randomized crossover study. Plasma levels of total cholesterol and LDL cholesterol were significantly higher at the end of the placebo period than with either sodium chloride (by 8.7 and 11.9%, respectively) (P less than 0.005) or sodium citrate (by 11.3% and 16.8%, respectively) (P less than 0.005). Thus this effect was dependent on sodium but not on chloride intake. Triglyceride and HDL-cholesterol levels were not affected by the dietary regimens. We conclude that short-term dietary sodium restriction may lead to a rise in plasma total and LDL cholesterol, thereby possibly increasing the risk of atherosclerotic vascular disease. Our findings render it possible that diuretic-induced lipid disturbances may also be caused by sodium depletion.

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)

Diuretics and the treatment of systemic hypertension

Diuretics are still among the most frequently used antihypertensive drugs in the treatment of hypertension. Their pharmacologic and hemodynamic properties are based on the water and salt metabolism in the pathophysiology of high blood pressure. Initially, there is a reduction of plasma and extracellular fluid volume; cardiac output also decreases. After this early phase, cardiac output returns to normal with an accompanying decrease in peripheral resistance so as to correct the underlying hemodynamic fault of the hypertensive state. Diuretics have a high therapeutic efficacy either as monotherapy or in combination with beta blockers, angiotensin-converting enzyme inhibitors or calcium antagonists. The main problem with the use of diuretics is related to their metabolic side effects, which are dose-related. Currently, there is a tendency to administer low-dose diuretics, which result in fewer clinical and metabolic side effects, but with a continued antihypertensive efficacy. Therefore, low doses of diuretics can be recommended as initial therapy in the stepped-care approach of hypertension.

Blood pressure, stroke, and coronary heart disease. Part 2, Short-term reductions in blood pressure: overview of randomised drug trials in their epidemiological context

There are 14 unconfounded randomised trials of antihypertensive drugs (chiefly diuretics or beta-blockers): total 37,000 individuals, mean treatment duration 5 years, mean diastolic blood pressure (DBP) difference 5-6 mm Hg. In prospective observational studies, a long-term difference of 5-6 mm Hg in usual DBP is associated with about 35-40% less stroke and 20-25% less coronary heart disease (CHD). For those dying in the trials, the DBP difference had persisted only 2-3 years, yet an overview showed that vascular mortality was significantly reduced (2p less than 0.0002); non-vascular mortality appeared unchanged. Stroke was reduced by 42% SD 6 (95% confidence interval 35-50%; 289 vs 484 events, 2p less than 0.0001), suggesting that virtually all the epidemiologically expected stroke reduction appears rapidly. CHD was reduced by 14% SD 5 (95% CI 4-22%; 671 vs 771 events, 2p less than 0.01), suggesting that just over half the epidemiologically expected CHD reduction appears rapidly. Although this significant CHD reduction could well be worthwhile, its size remains indefinite for most circumstances (though beta-blockers after myocardial infarction are of substantial benefit). At present, therefore, a sufficiently high risk of stroke (perhaps because of age, blood pressure, or, in particular, history of cerebrovascular disease) may be the clearest indication for antihypertensive treatment.

Spironolactone: a re-examination

A review of the aldosterone antagonist spironolactone is presented. It is effective both as monotherapy and in combination with other hypotensive agents in the control of both essential and hyperaldosterone-induced hypertension. It is useful as a diuretic in conditions such as cirrhosis and congestive heart failure, and is most commonly employed because of its potassium- and magnesium-sparing qualities. Spironolactone also has been used as an antiandrogenic agent in managing hirsutism. Its adverse effect profile, considered somewhat prohibitive in the past, is generally not significant when reasonably low doses (less than 150 mg/d) are used.

Effects of pindolol and propranolol on blood lipids in hypertensive patients

Since beta-blockers could affect lipid levels at the therapeutic dose range in hypertensive patients, a parallel 6-month randomized trial with pindolol (PDL) (16 pts.) and propranolol (PPL) (23 pts.) was designed (mean age = 55 + 7.1 years and 57 + 8.0 years; 9 males, 7 females and 15 males, 8 females, respectively). Total cholesterol, LDL and HDL fractions, and triglycerides (TGs) were determined before (washout phase) and during 1, 3, and 6 months of therapy. Patients were instructed to maintain their usual dietary habits. Daily drug doses were adjusted step by step to attain an optimal hypotensive effect (PDL 15-45 mg, PPL 180-240 mg). In the PPL-treated group, total cholesterol and LDL did not change significantly, HDL decreased (from 45.2 to 40.5 mg/dl, p less than 0.05) and TG increased (from 133 to 169 mg/dl, p less than 0.05). In the PDL group total cholesterol and LDL did not change either, but HDL increased (35.9 to 44.7 mg/dl, p less than 0.01) and TGs, were reduced (from 169 to 131 mg/dl, p less than 0.05). No dose-effect relationship was recorded. It is concluded that pindolol does not negatively influence HDL nor the TG blood lipid profile as does PPL. Accordingly, pindolol might be preferred to propranolol in the treatment of hypertensive patients with an unfavorable lipid profile, but this assumption remains to be proven in larger, prospective, long-term followup trials.

Traditional first-line therapy. Overview of medical benefits and side effects

When diuretic-based stepped care was first advocated for the treatment of hypertension, there were fewer classes of antihypertensive medication than there are today. In 1984, the third Joint National Committee on Detection, Evaluation, and Treatment of High Blood Pressure (JNC) for the first time suggested an alternative initial treatment with a beta-blocker in selected hypertensive patients, and the fourth JNC report has recommended the alternatives of calcium channel blockers or angiotensin converting enzyme inhibitors for step-one therapy as well. However, only the diuretic drugs and beta-blockers have been shown to reduce cardiovascular morbidity and mortality in prospective, long-term, controlled trials. Moreover, 30 years' experience with diuretic agents and 20 years' experience with beta-blockers have defined the advantages, disadvantages, and potential side effects of these drugs more precisely than is possible for newer agents. The diuretic drugs and beta-blockers remain excellent choices in the management of hypertension.

The effects of terazosin and methyclothiazide on blood pressure and serum lipids

This study compared the antihypertensive efficacy and the effects on serum lipids of terazosin, a new selective alpha 1-adrenergic antagonist, of methyclothiazide (MCTZ), and of the two drugs used as combination therapy. Adult patients with supine diastolic blood pressure ranging from 95 to 120 mm Hg were eligible to enter this double-blind, randomized, parallel-group study. Analyses of the blood pressure data from the 194 evaluable patients revealed that all three treatments produced significant (p less than 0.001) reductions in supine and standing systolic and diastolic blood pressures from baseline values. Moreover, combination therapy resulted in significantly greater mean blood pressure reductions than were observed with either drug used as monotherapy. In the group receiving terazosin monotherapy, the total serum cholesterol level, low-density lipoprotein plus very-low-density lipoprotein cholesterol fraction, and triglyceride level fell significantly (median changes of 3.7%, 5.0%, and 16.3%, respectively, p less than 0.05). However, in the group receiving MCTZ monotherapy, the total serum cholesterol level, low-density lipoprotein plus very-low-density lipoprotein cholesterol fraction, and triglyceride level increased significantly (4.7%, 7.1%, and 12.5%, respectively, p less than 0.001). In contrast, no significant changes from baseline values were observed for any lipid variable in the group receiving terazosin/MCTZ combination therapy. We conclude that terazosin is effective antihypertensive therapy that has a potentially beneficial effect on the serum lipid profile when used as monotherapy and that it counteracts the negative impact of MCTZ monotherapy on the serum lipid profile when used concurrently with this thiazide diuretic.

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.