Elevation of serum lipid levels during diuretic therapy of hypertension

[Antihypertensive therapy and lipid metabolism]

Hypertension, hyperlipidaemia and cigarette smoking are major risk factors in coronary heart disease. Since many antihypertensive drugs alter plasma lipid levels it is a subject of current discussion that these agents may increase associated coronary risk and therefore offset the beneficial effects of lowering blood pressure. The purpose of this paper is to review clinical and experimental data in the literature on the influence of data in the literature on the influence of antihypertensive drugs on lipid metabolism. The thiazides hydrochlorothiazide and chlorthalidone cause an elevation of plasma triglycerides and very low density lipoprotein (VLDL) but have little effect on total cholesterol, low density lipoprotein (LDL) and high density lipoprotein (HDL). The unspecific beta-blockers, e.g. propranolol, do not affect total cholesterol and LDL but increase total triglycerides and VLDL and decrease HDL. The changes of plasma lipids and lipoproteins caused by cardio-selective beta-blockers, e.g. atenolol and metoprolol, and unspecific beta-blockers with intrinsic sympathomimetic activity (ISA), e.g. oxprenolol and pindolol, appear to be qualitatively similar but less pronounced. The alpha 1-blocker prazosin reduces total triglycerides and slightly lowers total cholesterol. The concentration of VLDL plus LDL decreases while HDL may increase. Only very few studies have been reported on the effects of other antihypertensive drugs, e.g. clonidine, hydralazine, on plasma lipids. Several experimental studies reveal that antihypertensive agents exert direct effects on triglyceride and cholesterol metabolism. Although the pathophysiological mechanisms and the significance of the alterations of lipid metabolism induced by antihypertensive drugs are not yet clear, the following guidelines for the clinical use of these agents are recommended: (1) before initiating drug treatment in hypertensive patients, blood lipid levels should be measured to exclude a preexisting hyperlipidaemia, (2) during long-term therapy with antihypertensive agents, lipoprotein fractions should be controlled in order to reconsider the therapeutic regime if major alterations of blood lipid levels are observed.

Comparative effects of propranolol and prazosin upon serum lipids in thiazide- treated hypertensive patients

Earlier reported thiazide-induced changes in serum lipid concentrations were confirmed with increased triglyceride and total cholesterol levels. However, lipoprotein cholesterol ratios were unchanged. Propranolol caused further increases in triglyceride and very low-density lipoprotein cholesterol, and lowered high-density lipoprotein cholesterol and the high-density lipoprotein:total cholesterol ratio. With the addition of prazosin to the polythiazide regimen, there was a significant increase in serum high-density lipoprotein cholesterol when compared with the placebo.

Effects of long-term prazosin therapy on lipoprotein metabolism in hypertensive patients

Prazosin administration caused a significant and continuous antihypertensive effect when given as a single agent for 12 months. The daily dose was stabilized after three months at 6.0 mg per day. After 12 months of prazosin treatment, high-density lipoprotein cholesterol increased by 17 percent (p less than 0.005) and the cholesterol ratio increased by 19 percent (p less than 0.05), but total cholesterol was not significantly changed. There were no statistically significant changes in triglycerides, plasma renin activity, and plasma aldosterone concentration following treatment when compared with baseline levels. Prazosin monotherapy is concluded to have favorable effects on serum lipids and can be considered suitable for long-term antihypertensive therapy.

Efficacy of nadolol alone and combined with bendroflumethiazide and hydralazine for systemic hypertension

Nadolol (N) titrated from 80 to 240 mg or bendroflumethiazide (B) 5 to 10 mg, or the combination (B + N), were randomly assigned double-blind to 365 men with pretreatment diastolic blood pressures (BP) of 95 to 114 mm Hg. After 12 weeks of treatment, a diastolic BP of less than 90 mm Hg was achieved in 49% who received N, 46% who received B and 85% who received B + N. With N, the diastolic BP decreased more in whites than in blacks; with B, this racial trend was reversed. Side effects were infrequent; the most common were impotence, lethargy, weakness and postural dizziness, which occurred more often with B than with N. Addition of hydralazine, 25 to 100 mg twice daily, controlled diastolic BP at a level of less than 90 mm Hg in approximately 60% of those previously uncontrolled. N, and especially B + N, provided an efficacious once-daily treatment for systemic hypertension, and addition of hydralazine was effective in most nonresponders.

Oxprenolol in the treatment of hypertension in the elderly

Controversy continues to surround the value of drug treatment of hypertension in the elderly. Epidemiologic evidence implicates hypertension as a major risk factor in the precocious development of stroke and coronary heart disease in the elderly subject as clearly as it is implicated in the younger person. The hemodynamic and neuroendocrine profiles of the older patient with essential hypertension are similar to those of younger patients in the stable phase of the disease. However, the arterial ravages induced by many years of sustained hypertension render the circulation of the elderly subject more sensitive to pharmacologic intervention. The benefit-risk ratio of most antihypertensive drugs appears to be inversely related to age. Diuretics reduce the blood pressure at rest but have no influence on the increases in systolic pressure during normal activity; in addition, they carry potentially serious metabolic hazards in the elderly hypertensive patient. Centrally acting drugs likewise lower the blood pressure at rest without influencing the high systolic pressures induced by exercise. They also enhance the tendency to endogenous depression. Adrenergic-neurone blocking drugs and alpha-adrenoceptor antagonists are contraindicated because of the frequency of impaired cardiovascular reflexes in the elderly. The beta-blocking drugs can reduce the risk of coronary and cerebrovascular disease in the older patient with hypertension. They appear to be well tolerated, but because of their impaired metabolic handling in many elderly patients they should probably be used in smaller doses than those prescribed in younger patients. The influence of antihypertensive treatment on cardiovascular morbidity and mortality in the elderly hypertensive patient is not known.

Metabolic disturbances increasing the risk of coronary heart disease during diuretic-based antihypertensive therapy: lipid alterations and glucose intolerance

The treatment of hypertension reduces the incidence of stroke and congestive heart failure. Surprisingly, however, no reduction in morbidity from coronary heart disease (CHD) has been found in any of the placebo-controlled trials of hypertension treatment. This observation is unexpected because hypertension is a major risk factor for CHD. The one clinical trial demonstrating reduction of CHD with treatment of hypertension was not placebo controlled, thus provoking uncertainty about the cause of improvement. This article is a summary of the evidence that modest increases of 5% to 7% in serum total cholesterol during diuretic-based antihypertensive therapy offset, in part, the benefit expected from the lowering of blood pressure. Correlative data suggest a link between the lipid disturbance and the long-known glucose intolerance caused by diuretic drugs. The findings raise the possibility that treatment regimens free of these metabolic disturbances may provide the means for greater gains against CHD in patients with hypertension.

Influence of an angiotensin converting-enzyme inhibitor on diuretic-induced metabolic effects in hypertension

Diuretic therapy is frequently accompanied by undesirable biochemical changes and side-effects. Two multicenter trials compared the effects of captopril combined with a diuretic to the administration of either agent alone in mild-to-moderate hypertensives. In addition to blood pressure, effects on serum potassium, uric acid, glucose, and cholesterol were examined. The first study (Study A) was conducted on 210 such patients randomly assigned to receive: 1) hydrochlorothiazide (H) 15 mg three times daily (t.i.d.); 2) captopril (C) 25 mg t.i.d.; or 3) C + H for 6 weeks. The second study (Study B) involved 415 patients randomly assigned to receive: 1) C 25 mg twice daily (b.i.d.) + H 25 mg b.i.d.; 2) C 50 mg b.i.d. + H 25 mg b.i.d.; 3) C 50 mg b.i.d. + placebo b.i.d.; 4) placebo b.i.d. + H 25 mg b.i.d.; or 5) placebo b.i.d. + placebo b.i.d. for 6 weeks. In both Studies A and B, all patients except those receiving placebo only (Study B-5) had significant (p less than 0.05) blood pressure reductions. In Study A, the combination of C + H (A-3) produced a significantly greater (p less than 0.001) reduction in blood pressure than either agent alone. In Study B, both C + H groups (B-1, B-2) had a significantly greater (p less than 0.01) blood pressure reduction than that seen with C alone (B-3). In Study A, those treated with H alone (A-1) had a significant (p less than 0.05) reduction in serum potassium and increases in uric acid, glucose, and cholesterol when compared to C alone (A-2) where no changes in these parameters were observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Thiazides, beta blockers and lipoproteins

Some of the more important recent studies on the effect of thiazides and beta-adrenoceptor blocking agents is conflicting, possibly because of differences in patient compliance and in lipoprotein methodology and quality assurance between studies. It is likely that in the short-term, thiazide diuretics produce an increase in plasma triglyceride and cholesterol and in LDL-cholesterol. No consistent effect of monotherapy with beta-adrenoceptor blocking agents was seen. Further long-term studies of monotherapy with both of these classes of drugs are required. Combined therapy with thiazides or beta-adrenoceptor blocking agents consistently increased plasma triglyceride concentrations, but their effect on VLDL, LDL and HDL concentrations is uncertain. Further research required into the effect of these drugs on apolipoproteins which may be useful discriminators for patients with coronary heart disease (Avogaro et al., 1979) and on HDL subfractions.

Thiazide-induced disturbances in carbohydrate, lipid, and potassium metabolism

Long-term thiazide diuretic therapy for hypertension is associated with disturbances in carbohydrate, lipid, and potassium metabolism that theoretically may have serious adverse effects. It appears that diuretic-induced hypokalemia interferes with production of insulin, producing mild elevations of blood glucose in nondiabetic patients. The insulinopenia worsens glucose metabolism in prediabetic and type II diabetic patients. Increases in low-density lipoprotein cholesterol, triglycerides, and the low-density lipoprotein/high-density lipoprotein cholesterol ratio are frequently seen following thiazide treatment of hypertension. These changes are more pronounced in younger patients. Decrements of serum potassium of 0.6 mEq/L are commonly observed with diuretic therapy. Usually, patients remain asymptomatic and no potassium replacement is necessary. In patients with underlying heart disease, however, alterations in potassium metabolism may produce increased frequency and complexity of ventricular ectopic activity. All these metabolic disturbances appear to be, in part, dose related, and there is currently no evidence that they have clinical significance.

Indapamide in the treatment of essential arterial hypertension: results of a controlled study

A double-blind trial was carried out in 24 patients with mild hypertension to compare the efficacy and tolerability of indapamide with that of a standard thiazide diuretic, hydrochlorothiazide. After a 6-week washout period on placebo, patients received either 2.5 mg indapamide or 50 mg hydrochlorothiazide per day for 12 weeks. Blood pressure and pulse rate in the recumbent and upright positions were monitored at regular intervals. Laboratory measurements of plasma electrolytes, other biochemical and haematological parameters were made before and after active treatment. The results showed that indapamide treatment produced a statistically significant reduction from placebo levels in diastolic pressure in both the upright and recumbent positions, whereas the reduction was significant only in the upright diastolic pressure with hydrochlorothiazide. There were no significant changes in pulse rate in either active-treatment period. Both drugs produced small but significant reductions in mean plasma chloride and potassium levels, and there was a significant increase in mean serum uric acid in patients receiving hydrochlorothiazide. None of these changes, however, were of clinical importance and all of the patients completed the study.

Long term treatment with tienilic acid or thiazides: comparison of antihypertensive and metabolic effects

A comparison has been made of arterial pressure and major metabolic parameters during long term treatment with tienilic acid and a hydrochlorothiazide-amiloride combination, using a randomized single-blind study without cross-over. A significant fall in systolic and diastolic blood pressure and no change in most biochemical parameters was observed with both drugs. Serum uric acid concentration was decreased during tienilic acid and was slightly increased whilst subjects took the hydrochlorothiazide-amiloride combination; serum potassium was slightly decreased on tienilic acid. No sign of hepatotoxicity was detected.

Side effects of diuretics

Diuretics are amongst the most widely used drugs. Fortunately enough, there are rather few clinically relevant side effects. The following side effects are discussed in this paper: disturbances of electrolyte, acid-base- and water balance, metabolic changes (uric-acid, carbohydrate-metabolism, lipid metabolism), unspecific side effects and drug interactions. Finally the prevention of side reactions of diuretics is briefly mentioned.

Effects of indapamide and various diuretics alone or combined with beta-blockers on serum lipoproteins

A prospective evaluation was started in 1976 to study the influence of diuretics alone or combined with beta-blockers on serum lipoproteins in normal or hypertensive subjects. Compared to placebo conditions, 4 or 6-weeks' monotherapy with various diuretics significantly (p less than 0.05) increased the beta-lipoprotein fraction (furosemide, 80 mg/day or chlorthalidone, 100 mg/day; n = 16) or low-density lipoprotein-cholesterol (LDL-C) (chlorthalidone, 100 mg/day, n = 27 men; tienilic acid, 250 mg/day, n = 16 men, clopamide, 5 mg/day, n = 17 men; or muzolimine, 20 to 40 mg/day, n = 13 men or post-menopausal women). No increase in LDL-C was noted in 43 men (32 normal, 11 with mild hypertension) treated with indapamide, 2.5 mg/day. Serum high-density lipoprotein-cholesterol and apoproteins A1, A2 and B were not consistently changed by any of these agents. In women, chlorthalidone (100 mg/day) significantly increased LDL-C in the (100 mg/day) significantly increased LDL-C in the post-menopausal (n = 18) but not in the pre-menopausal (n = 22) state. Increases in LDL-C caused by chlorthalidone monotherapy were prevented or reversed by the addition of a beta-blocker, usually propranolol or atenolol (n = 18); increases in LDL-C during clopamide monotherapy were reversed after the addition of the beta-blocker pindolol (10 mg/day, n = 17). In all studies, variations in beta-lipoprotein or LDL-C levels could not be explained by changes in blood volume, serum glucose or insulin and did not correlate with alterations in blood pressure, plasma potassium, renin, aldosterone, adrenaline or noradrenaline. These observations indicate that various diuretics may increase serum LDL-C in men or post-menopausal women. Pre-menopausal women may often be protected from this side-effect. Long-term studies are now needed to clarify the pathogenic and prognostic relevance of lipoprotein changes induced by diuretics. In the meantime, it is of clinical interest that indapamide had no significant effect on serum lipoproteins and that certain beta-blockers appear to prevent or reverse increases in LDL-C during diuretic treatment in men and post-menopausal women.

The impact of elevated blood pressure upon 10-year mortality among Japanese men in Hawaii: the Honolulu Heart Program

The impact of blood pressure upon total and cause-specific mortality during 10 years of follow-up was studied for 7610 Japanese men in Hawaii, aged 45-68 at baseline examination. The age adjusted rate of total mortality for men with definite hypertension (WHO criteria) was twice that for normotensive men. The relative risk of mortality was five for all cardiovascular diseases (CVD), four for coronary heart disease (CHD), and six for stroke. Men with borderline hypertension also had significantly high mortality rates intermediate between the definite hypertensives and the normotensives. Both systolic blood pressure (SBP) and diastolic blood pressure (DBP) were the most important independent predictors of total, CVD, CHD and stroke mortality in multivariate analysis, taking account of 11 other known risk factors. However, SBP was more strongly related to total, CVD and CHD mortality than was DBP, whereas the reverse was true for stroke mortality. There was no significant association of either SBP or DBP with cancer and other non-cardiovascular mortality in multivariate analysis. Men who were receiving antihypertensive medication at baseline examination had a higher mortality from CVD, CHD and stroke as compared to untreated men in every category of blood pressure status. This apparently paradoxical finding probably reflects more advanced status of hypertension existing before treatment rather than adverse effects of drugs per se; however, this latter possibility cannot be dismissed.

Serum lipoproteins in patients with mild renal disease treated with the diuretic muzolimine

Patients with renal functional impairment are prone to develop hypertension and hyperlipidemia, and both abnormalities tend to occur already at an early stage of kidney disease. In 18 patients with mild renal disease (glomerular filtration rate 65 +/- 5 ml/min) and hypertension (mean blood pressure 126 +/- 4 mm Hg), the effect of six weeks of treatment with the loop-diuretic muzolimine on serum lipoproteins was assessed. Compared to placebo values, the diuretic significantly increased serum low-density lipoprotein cholesterol (LDL-C) and apoprotein B (+ 18 and 11%, respectively, P less than 0.005) in 13 men or postmenopausal women, but not in 5 premenopausal women. Serum high-density lipoprotein cholesterol (HDL-C), and total triglycerides or lipoprotein triglyceride fractions were not consistently changed in both subgroups. Thus, the ratio LDL-C/HDL-C was increased from 3.2 +/- 0.3 to 3.9 +/- 0.3 (P less than 0.05) in the men or postmenopausal women, while no such tendency occurred in the premenopausal women (4.1 +/- 0.6 to 3.7 +/- 0.6). Changes in serum LDL-C were not associated with hemoconcentration or alterations in carbohydrate metabolism and were not related to variations in serum potassium or blood pressure. Increased serum levels of the atherogenic LDL-C fraction during diuretic treatment in men or postmenopausal women with renal disease may represent a potentially undesirable effect, particularly since such patients may tend to have hyperlipidemia in the untreated state.

The effect of moderate physical exercise on the plasma lipoprotein subfractions of male survivors of myocardial infarction

The effect of regular, moderate exercise on the lipoprotein subfractions of male survivors of myocardial infarction was studied. Nineteen men were randomly allocated to an incremental exercise program and 23 to a control group. Both groups were studied for 6 months. No change occurred in any lipoprotein class in the control group. In the trained group, total triglyceride and low-density lipoprotein (LDL) cholesterol concentrations decreased significantly (0.01 greater than p greater than 0.001 and 0.05 greater than p greater than 0.01, respectively) and high-density lipoprotein (HDL) cholesterol and apolipoprotein A-1 rose (both p less than 0.001). The concentration of the HDL2 subfraction increased with training (0.01 greater than p greater than 0.001) and HDL2 did not change. No relationship was found between changes in lipoproteins and treadmill exercise test performance. Thus, in survivors of myocardial infarction, exercise may alter plasma lipoprotein values beneficially.

Improvement of glucose tolerance and lowering of glycohemoglobin and serum lipid concentrations after discontinuation of antihypertensive drug therapy

Diuretic-based antihypertensive drug therapy causes a disturbance in glucose tolerance and in serum lipid and lipoprotein concentrations. To determine the reversibility of the glucose intolerance and to identify mechanisms of the metabolic alterations, we examined a short glucose tolerance test and insulin, glycohemoglobin and lipid concentrations during the supervised withdrawal of long-term drug therapy in 35 patients with primary hypertension. An average of 7 weeks after stopping drugs, glucose tolerance and glycohemoglobin improved, total cholesterol decreased 18 mg/dl, triglyceride decreased 27 mg/dl, and the ratio of total to high-density lipoprotein cholesterol decreased (p less than 0.01 for all variables vs treatment values). The changes in lipid concentrations from the treated to untreated state correlated with the changes in glycohemoglobin and indexes of glucose metabolism. The findings suggest that insulin resistance develops during drug therapy and disturbs both glucose and lipid metabolism. Attention to these alterations may provide directions for further control of atherosclerotic complications during the treatment of hypertension.

Antihypertensive drugs and blood lipids: the Oslo study

1 The report presents the effects on blood lipids and uric acid of six different antihypertensive drugs, used alone and of five different combinations of two antihypertensive drugs. 2 Prazosin significantly lowered serum LDL + VLDL cholesterol and total triglycerides. Atenolol lowered LDL + VLDL cholesterol to a smaller but significant extent. Both pindolol and hydrochlorothiazide (HCTH) were without effect, while oxprenolol significantly increased total triglycerides. Propranolol significantly lowered HDL cholesterol and increased total triglycerides and uric acid. 3 The combination prazosin and pindolol had a favourable effect on the lipid profile, while the combination propranolol and HCTH lowered HDL cholesterol but increased total triglycerides. Propranolol and prazosin lowered HDL cholesterol, while methyldopa and HCTH, and HCTH and amiloride were without effect on blood lipids. 4 It is suggested that the metabolic effects of antihypertensive drugs could be of special importance in long-term treatment of mild hypertension.

Spouse concordance of plasma cholesterol and triglyceride

Spouse concordance for plasma cholesterol and triglyceride was studied in 1971 spouse pairs including 545 spouse pairs married 40 or more years. Both lipids showed modest but statistically significant age corrected Kendall Tau-B correlations; 0.046 (P = 0.005) for cholesterol and 0.070 (P = 0.0001) for triglycerides. Concordance was not explained by season of sampling or by selective mortality. Relative weight was positively correlated in spouse pairs and appeared to explain much of the observed correlations in cholesterol and triglycerides. Spouse pairs also showed positive correlations for cigarette smoking and egg and milk consumption, though these behavioral variables explained little of the concordance for cholesterol and triglycerides. Lipid concordance was highest in marriages of the shortest (1-9 yr) and longest (40 + yr) durations, as was relative weight concordance, suggesting an interaction between duration of marriage and environmental and/or selective factors affecting plasma lipids.

Effect of slow oxprenolol and a combination of slow oxprenolol and cyclopenthiazide on plasma lipoproteins

The effect of slow oxprenolol on plasma lipoprotein concentrations was compared to that of combined therapy with slow oxprenolol and cyclopenthiazide. The design of the study was a double blind between patient investigation in which 9 subjects with mild hypertension received slow oxprenolol and 11 slow oxprenolol and cyclopenthiazide. Plasma lipoproteins were analysed at 0, 2, 4, 8, 12 and 16 weeks. Slow oxprenolol given alone resulted in a significant rise in plasma and low density lipoprotein (LDL) cholesterol concentration whereas combined therapy with slow oxprenolol and cyclopenthiazide produced significant rises in plasma and very low density lipoprotein (VLDL) triglyceride. If one accepts that a rise in plasma or LDL cholesterol increases atherogenic risk more than a rise in plasma or VLDL triglyceride combined therapy is preferable.

Diuretic treatment and serum lipoproteins: effects of tienilic acid and indapamide

Treatment with the commonly used diuretic, chlorthalidone, has previously been found to increase the serum low-density-lipoprotein cholesterol (LDL-C) fraction. Therefore, the effects of two new agents, tienilic acid (a combined diuretic-uricosuric) and indapamide on serum lipid and lipoprotein levels were assessed. Six weeks of treatment with tienilic acid, 250 mg/day, markedly decreased serum uric acid and significantly increased LDL-C and triglycerides in 16 men. In contrast, indapamide 2.5 mg/day, had no apparent influence on serum lipids or lipoproteins in 18 men.

Beta adrenoreceptor-blocking drugs once daily in essential hypertension: a comparison of propranolol, pindolol and atenolol

Atenolol, Pindolol and Propranolol in single daily doses administered to 18 selected patients with mild essential hypertension achieved adequate control of blood pressure. Chlorothiazide had been initially administered twice a day without full control of blood pressure and this diuretic therapy was continued unaltered throughout the study. Methacholine challenge testing of respiratory function was performed during the placebo phase and with each beta adrenoreceptor-blocking drug. In the 18 non-asthmatic patients, the reduction in FEV1, was significant only for propranolol therapy when compared to placebo. Each beta adrenoreceptor-blocking drug was associated with small, but significant, increases in fasting plasma triglyceride concentrations and suppression of fasting immuno-reactive glucagon concentrations.

Treatment of mild hypertension: a five year controlled drug trial. The Oslo study

In 1972--1973, 785 symptom-free men, aged 40 to 49 years, without target organ damage, with systolic blood pressures between 150 and 179 mm Hg and diastolic blood pressure below 110 mm Hg, were assigned at random to one of two groups: (406 to a drug treatment group and 379 to a control group) for a five-year controlled drug treatment trial to evaluate the effect of therapy on cardiovascular complications. Drug treatment started with hydrochlorothiazide. If systolic blood pressure remained above 140 mm Hg and/or diastolic blood pressure above 90 mm Hg, alphamethyldopa was added. If there were side effects, methyldopa was replaced with propranolol. The control group was not given a placebo. The mean observation time was 66 months (range 60 to 78 months). A difference in blood pressure between groups of about 17 mm Hg systolic and 10 mm Hg diastolic was maintained throughout the study. The study protocol had a rather low "ethical" blood pressure roof, 180 mm Hg systolic and/or 110 mm Hg diastolic. Seventeen percent of the control group had an increase in blood pressure above this level during the trial, and drug treatment was started. There was no effect on major cardiovascular morbidity comparing groups as established by randomization, with 18 events in the treatment group and 20 events in the control group. There was no difference between the groups in total mortality and mortality from cardiovascular events. However, in the subgroups with diastolic blood pressure greater than or equal to 100 mm Hg before randomization, there was a probable reduction in total morbidity from cardiovascular events in favor or the group receiving drug therapy, 7.6 and 16.4 percent events in the treated and control groups, respectively. Cerebrovascular events occurred only in the control group, 7 versus 0. Two cases of fatal aortic aneurysms also occurred in the control group. Other "pressure" complications, such as marked left ventricular hypertrophy in the electrocardiogram and left ventricular failure, occurred only in the control group. However, regarding coronary heart disease, including sudden death, the incidence tended to be higher in the treated group, although it was not statistically significant. Only 13 men (1.7 percent) failed to meet for regular examinations. At the end of the study these men were also followed up with regard to possible cardiovascular events.

Thiazides and acute cholecystitis

An association between acute cholecystitis and the use of thiazide-containing drugs was observed during routine screening of data from a case-control drug-surveillance program. Evaluation of this relation among 419 patients with acute cholecystitis and 1676 control patients yielded a relative risk estimate of 2.0 for subjects who had used thiazides in the month before admission, as compared with subjects who had never used these drugs (95 per cent confidence interval, 1.4 to 2.7). There was a significant trend of increasing relative risk with increasing duration of use (P < 0.01), and the estimate for subjects who had used thiazides for five or more years was 2.9. The association was not explained by confounding due to the indications for thiazide use, such as hypertension, or other factors, such as obesity or the use of other drugs. No single epidemiologic study can eliminate chance or bias as an explanation for an association; the relation found here should be regarded as a hypothesis that requires independent confirmation.

Clinical and biochemical effects of spironolactone administered once daily in primary hypertension. Multicenter Sweden study

In a prospective, double-blind, intraindividual, cross-over, placebo-controlled multicenter study, clinical and biochemical effects of once daily postprandial dose regimens of 50, 100, and 200 mg spironolactone were investigated in 45 outpatients with primary hypertension, WHO (World Health Organization) Stage I-II. Each of the three active therapy periods, which were randomly allocated to patients, were of 2 months' duration, with intervening placebo periods, Clinical and biochemical parameters, including furosemide-stimulated plasma renin activity (PRA), were recorded at regular intervals. All three spironolactone doses resulted in statistically significant blood pressure (BP) reductions independent of initial pretreatment levels and yielded satisfactory BP control in more than half of the patients. The 200 mg daily dose of spironolactone was found to be more effective than 50 but not 100 mg. When, correlating blood pressure response (delta MAP) to PRA, the profiling for positive spironolactone responders was characterized by high age and low PRA, irrespective of sex. Spironolactone therapy resulted in decreased serum sodium and magnesium values; potassium, creatinine, urate, and triglyceride levels were increased. However, all treatment values were within normal ranges. Side effects were infrequent and mainly of endocrine nature.

The effect of chlorthalidone on serum lipids and lipoproteins

The effect of chlorthalidone treatment on serum lipids and lipoproteins was investigated in 21 hypertensive patients. Chlorthalidone caused an increase in total serum and low density lipoprotein (LDL) cholesterol, but not in high density lipoprotein (HDL) cholesterol. Serum and lipoprotein triglycerides also increased. Our findings suggest that chlorthalidone increases serum concentrations of "atherogenic" lipoproteins (LDL and VLDL), and possibly decreases the levels of a "beneficial" lipoprotein, namely HDL. Thus, the use of this medication may increase a major atherosclerosis risk factor.

The effect of metoprolol and atenolol on plasma high density lipoprotein levels in man

1. The effects of two beta-adrenoreceptor blocking drugs, metoprolol and atenolol, on plasma lipoproteins were studied in thirty-four patients using a single-blind cross-over design, with a 10-day placebo washout period between drugs. 2. Compared with placebo values, neither metoprolol nor atenolol influenced total plasma cholesterol levels, while total plasma triglycerides increased slightly. 3. Low density lipoprotein protein level remained unaltered, while high density lipoprotein (HDL) cholesterol and protein were significantly reduced by both beta-adrenoreceptor blockers. 4. The ratio of total cholesterol to HDL cholesterol was increased by both drugs. 5. The data suggest that patients taking these drugs over many years may be exposing themselves to increased vascular risk, despite other anticipated benefits from such therapy.

[Secondary hyperlipoproteinemia induced by diuretic therapy (author's transl)]

In order to study the degree and pathogenic aspects of the secondary hyperlipoproteinemia in patients under diuretic therapy we measured serum lipids, lipoproteins and the apoproteins A1, A2 and B in 12 adults after a 4 weeks placebo period and 6 weeks of treatment with chlorthalidon. There was a significant increase in atherogenic low density lipoproteins (LDL), (18%, P less than 0.05) whereas the high density lipoprotein-cholesterol Apo A1 and A2 levels were not significantly altered. The same was true for the total serum triglyceride- and the very low density lipoprotein- and LDL-triglyceride levels. The activity of lipoprotein lipase and hepatic triglyceride lipase was slightly but not significantly increased. A delayed LDL-catabolism seems to be the most probable pathogenic mechanism underlying the Chlorthalidon-induced hyperlipoproteinemia.

Increased serum low-density lipoprotein cholesterol in men treated short-term with the diuretic chlorthalidone

The effect of the diuretic chlorthalidone (100 mg/day for 6 weeks) on serum lipoproteins was evaluated in 37 subjects. In 19 men with essential hypertension (aged 41 +/- 3 yr), 8 normal men (26 +/- 3 yr), or all of these men considered together, chlorthalidone significantly increased serum low density lipoprotein--cholesterol (LDL-C) by 20% (p less than 0.05 to less than 0.01). There was also a tendency for increased LDL-C in seven postmenopausal women (+/- 15%) but not in three premenopausal women with essential hypertension. High density lipoprotein--cholesterol was not significantly changed in hypertensive women or normal men and decreased slightly (p less than 0.05) in hypertensive men. Apolipoproteins A-I, A-II, and B were not changed significantly in women or men. Diuretic-induced lipoprotein alterations were not associated with altered plasma volume and unrelated to variations in serum potassium, glucose, insulin levels, blood pressure, and body weight. Short-term diuretic therapy with chlorthalidone may increase serum LDL-C in young or middle-aged men with normal or high blood pressure.

Effects of hypertension and its reversal on aortic intima lesions of the rat

A combined transmission (TEM) and scanning (SEM) electron microscopic study was performed on aortae of deoxycorticosterone-salt (DOC-salt)-treated rats and spontaneously hypertensive rats (SHR) to compare the effects of hypertension as well as its reversal on the aortic intima. To best reproduce the in vivo state of the vasculature, rats were perfusion-fixed at pressures corrected for each individual animal (30 mm Hg below measured systolic pressure). The intimal alterations were focal and thus were best appreciated with the combined use of SEM and TEM. Qualitatively, both models of hypertension showed similar intimal changes, which consisted of subintimal thickening due to an accumulation of both extracellular material and cells. Subendothelial cells with a morphology indicating a blood-borne origin were present simultaneously with cells derived from the vessel wall. The increased subendothelial extracellular material included precipitated plasma proteins, reticulated basement membrane, collagen fibers, and fragments of elastin. Increase in the height of endothelial cells with distortion of nuclear shape was prominent. Withdrawal of DOC-salt combined with low-salt diet for 11 weeks did not result in a discernible regression of these intimal changes despite normalization of blood pressure. We conclude that vascular injury, once induced, may be difficult to reverse and suggest that areas of prior damage may serve as foci for later vascular complications.

The effect of metoprolol on plasma lipids

Fifteen hypertensive patients entered a single-blind study to examine the effects of metoprolol (100 mg twice daily) on fasting plasma lipids. In 12 patients who completed the study, non-esterified fatty acid concentrations fell, but cholesterol and triglyceride levels were unchanged after 12 weeks' treatment. These results conflict with earlier reports of the effect of metoprolol on plasma triglyceride concentrations.

Metabolic consequences of atenolol and propranolol in treatment of essential hypertension

A six-month study of triglyceride, cholesterol, free fatty acid (FFA), glucose, insulin, growth hormone, and glucagon concentrations was carried out in asymptomatic hypertensive normal-weight men randomly allocated to treatment with atenolol or propranolol. A highly significant increase in the basal plasma triglyceride concentration was observed in propranolol-treated patients after three and six months' treatment, with a smaller but significant increase in atenolol-treated subjects after six months' treatment. The changes in triglyceride concentration could not be ascribed to variations in plasma insulin, growth hormone, or glucagon concentrations. Basal FFA concentrations were reduced during the first three months of treatment in both groups but returned to pretreatment levels after six months. Plasma cholesterol concentrations were unchanged by either agent.

Influence of hydrochlorothiazide on the plasma levels of triglycerides, total cholesterol and HDL-cholesterol in patients with essential hypertension

The influence of hydrochlorothiazide (HCT) treatment on the plasma levels of triglycerides, total cholesterol and high density lipoprotein cholesterol (HDL-cholesterol) was studied in 10 patients with essential hypertension. After a placebo period of 4 weeks, 50 mg HCT twice daily was given for a period of 9 months, followed by a second placebo period of 4 weeks. Triglycerides, total cholesterol and HDL-cholesterol were determined at the end of both placebo periods and after 1, 3, 6 and 9 months of HCT. For the whole group, there were no significant changes in triglycerides or HDL-cholesterol, whereas total cholesterol significantly increased during HCT. In 6 patients, plasma triglycerides were higher during HCT as compared to both placebo periods. In only 4 patients did HDL-cholesterol increase during HCT. Changes in triglycerides, total cholesterol and HDL-cholesterol were not related and no correlation was found with changes in blood pressure, body weight or serum potassium. In conclusion, this study confirms a possible adverse effect of diuretic treatment on plasma lipids, which should be considered when determining therapeutic regimens for hypertension.

Double-blind comparison of metoprolol, alprenolol, and oxprenolol in hypertension

A double-blind comparison of the beta-blockers metoprolol, alprenolol and oxprenolol was carried out to evaluate their antihypertensive effect and tolerability. 105 patients with previously untreated hypertension entered the trial and 72 completed it. Side-effects were infrequent and were never the reason for drop-out. All three drugs caused a statistically significant reduction in blood-pressure at the lower of the two doses used during a dose-finding period. At the higher dose employed in this period, metoprolol caused a significantly greater reduction in diastolic blood-pressure than did alprenolol or oxprenolol. All three drugs caused a significant reduction in heart rate. During the following period, the beta-blockers were supplemented if necessary with hydrochlorothiazide. This was required less frequently in the metoprolol group than in the other two groups.