Normalization of lipid metabolism after withdrawal from antihypertensive long-term therapy with beta blockers and diuretics

Antihypertensive withdrawal for the prevention of cognitive decline

BACKGROUND

Clinical trials and observational data have variously shown a protective, harmful or neutral effect of antihypertensives on cognitive function. In theory, withdrawal of antihypertensives could improve cerebral perfusion and reduce or delay cognitive decline. However, it is also plausible that withdrawal of antihypertensives may have a detrimental effect on cognition through increased incidence of stroke or other vascular events.

OBJECTIVES

To assess the effects of complete withdrawal of at least one antihypertensive medication on incidence of dementia, cognitive function, blood pressure and other safety outcomes in cognitively intact and cognitive impaired adults.

SEARCH METHODS

We searched ALOIS, the specialised register of the Cochrane Dementia and Cognitive Improvement Group, with additional searches conducted in MEDLINE, Embase, PsycINFO, CINAHL, LILACS, Web of Science Core Collection, ClinicalTrials.gov and the World Health Organization Portal/ICTRP on 12 December 2015. There were no language or date restrictions applied to the electronic searches, and no methodological filters were used to restrict the search.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and controlled clinical trials (CCTs) provided they compared withdrawal of antihypertensive medications with continuation of the medications and included an outcome measure assessing cognitive function or a clinical diagnosis of dementia. We included studies with healthy participants, but we also included studies with participants with all grades of severity of existing dementia or cognitive impairment.

DATA COLLECTION AND ANALYSIS

Two review authors examined titles and abstracts of citations identified by the search for eligibility, retrieving full texts where needed to identify studies for inclusion, with any disagreement resolved by involvement of a third author. Data were extracted independently on primary and secondary outcomes. We used standard methodological procedures expected by Cochrane.The primary outcome measures of interest were changes in global and specific cognitive function and incidence of dementia; secondary outcomes included change in systolic and diastolic blood pressure, mortality, adverse events (including cardiovascular events, hospitalisation and falls) and adherence to withdrawal. The quality of the evidence was evaluated using the GRADE approach.

MAIN RESULTS

We included two RCTs investigating withdrawal of antihypertensives in 2490 participants. There was substantial clinical heterogeneity between the included studies, therefore we did not combine data for our primary outcome. Overall, the quality of included studies was high and the risk of bias was low. Neither study investigated incident dementia.One study assessed withholding previously prescribed antihypertensive drugs for seven days following acute stroke. Cognition was assessed using telephone Mini-Mental State Examination (t-MMSE) and Telephone Interview for Cognitive Status (TICS-M) at 90 days as a secondary outcome. The t-MMSE score was a mean of 1.0 point higher in participants who withdrew antihypertensive medications compared to participants who continued them (95% confidence interval (CI) 0.35 to 1.65; 1784 participants) and the TICS-M was a mean of 2.10 points higher (95% CI 0.69 to 3.51; 1784 participants). However, in both cases the evidence was of very low quality downgraded due to risk of bias, indirectness and evidence from a single study. The other study was community based and included participants with mild cognitive impairment. Drug withdrawal was for 16 weeks. Cognitive performance was assessed using a composite of at least five out of six cognitive tests. There was no evidence of a difference comparing participants who withdrew antihypertensive medications and participants who continued (mean difference 0.02 points, 95% CI -0.19 to 0.21; 351 participants). This evidence was of low quality and was downgraded due to risk of bias and evidence from single study.In one study, the systolic blood pressure after seven days of withdrawal was 9.5 mmHg higher in the intervention compared to the control group (95% CI 7.43 to 11.57; 2095 participants) and diastolic blood pressure was 5.1 mmHg higher (95% CI 3.86 to 6.34; 2095 participants). This evidence was low quality, downgraded due to indirectness, because the data must be interpreted in the context of the wider study looking at glyceryl trinitrate administration or not, and evidence from a single study. In the other study, systolic blood pressure increased by 7.4 mmHg in the withdrawal group compared to the control group (95% CI 7.08 to 7.72; 356 participants) and diastolic blood pressure increased by 2.6 mmHg (95% CI 2.42 to 2.78; 356 participants). This was moderate quality evidence, downgraded as evidence was from a single study. We combined data for mortality and cardiovascular events. There was no clear evidence that antihypertensive medication withdrawal affected adverse events, although there was a possible trend to increased cardiovascular events in the large post-stroke study (pooled mortality risk ratio 0.88, 95% CI 0.72 to 1.08; 2485 participants; and cardiovascular events risk ratio 1.29, 95% CI 0.96 to 1.72). Certain prespecified outcomes of interest (falls, hospitalisation) were not reported.

AUTHORS' CONCLUSIONS

The effects of withdrawing antihypertensive medications on cognition or prevention of dementia are uncertain. There was a signal of a positive effect in one study looking at withdrawal after acute stroke but these results are unlikely to be generalisable to non-stroke settings and were not a primary outcome of the study. Withdrawing antihypertensive drugs was associated with increased blood pressure. It is unlikely to increase mortality at three to four months' follow-up, although there was a signal from one large study looking at withdrawal after stroke that withdrawal was associated an increase in cardiovascular events.

Consequences of the discontinuation of antihypertensive treatment in successfully treated patients

Hypertension is probably the most important public health problem in developed countries. Over the last 40 years, an increasing number of hypertensive patients have been treated with various antihypertensive drugs. If the blood pressure (BP) is controlled, the discontinuation of the antihypertensive drug may result either in a relapse of the disease or in the maintenance of normal BP for a long time. In this study, we discuss the available data regarding the consequences of antihypertensive drug withdrawal in successfully treated patients and we suggest guidelines for the application in clinical practice.

Integrated effects of the vasodilating beta-blocker nebivolol on exercise performance, energy metabolism, cardiovascular and neurohormonal parameters in physically active patients with arterial hypertension

OBJECTIVE

The present study was designed to investigate the integrated effects of the beta-1-selective blocker with vasodilator properties, nebivolol, on systemic haemodynamics, neurohormones and energy metabolism as well as oxygen uptake and exercise performance in physically active patients with moderate essential hypertension (EH).

DESIGN AND METHODS

Eighteen physically active patients with moderate EH were included: age: 46.9 +/- 2.38 years, weight: 83.9 +/- 2.81 kg, blood pressure (BP): 155.8 +/- 3.90/102.5 +/- 1.86 mm Hg, heart rate: 73.6 +/- 2.98 min(-1). After a 14-day wash-out period a bicycle spiroergometry until exhaustion (WHO) was performed followed by a 45-min submaximal exercise test on the 2.5 mmol/l lactate-level 48 h later. Before, during and directly after exercise testing blood samples were taken. An identical protocol was repeated after a 6-week treatment period with 5 mg nebivolol/day.

RESULTS

Nebivolol treatment resulted in a significant (P < 0.01) decrease in systolic and diastolic BP and heart rate at rest and during maximal and submaximal exercise. Maximal physical work performance, blood lactate and rel. oxygen uptake (rel. VO(2)) before and after nebivolol treatment at rest and during maximal and submaximal exercise remained unaltered. Free fatty acid, free glycerol, plasma catecholamines, beta-endorphines and atrial natriuretic peptide (ANP) increased before and after treatment during maximal and submaximal exercise but remained unaltered by nebivolol treatment. In contrast, plasma ANP levels at rest were significantly higher in the presence of nebivolol, endothelin-1 levels were unchanged.

CONCLUSIONS

Nebivolol was effective in the control of BP at rest and during exercise in patients with EH. Furthermore, nebivolol did not negatively affect lipid and carbohydrate metabolism and substrate flow. The explanation for the effects on ANP at rest remain elusive. This pharmacodynamic profile of nebivolol is potentially suitable in physically active patients with EH.

Comparison between moexipril and atenolol in obese postmenopausal women with hypertension

The present study investigated the effect of the new ACE-inhibitor moexipril versus the beta 1-adrenergic blocker atenolol on metabolic parameters, adverse events (AEs) and sitting systolic (SSBP) and sitting diastolic blood pressure (SDBP) in obese postmenopausal women with hypertension (stage I and II). After a 4-week placebo run-in phase, 116 obese, postmenopausal women with primary hypertension were randomised into two treatment groups receiving once daily dosages of either moexipril 7.5 mg or atenolol 25 mg initially (mean age: 57 +/- 7 years in both groups; mean weight: 94 kg in the moexipril group and 89 kg in the atenolol group, corresponding to a body mass index (BMI) of 35.2 kg/m2 and 34.1 kg/m2 in both groups, respectively). After 4 and 8 weeks, the dosages were uptitrated to moexipril 15 mg, or if necessary to moexipril 15 mg/hydrochlorothiazide (HCTZ) 25 mg, or to atenolol 50 mg and atenolol 50 mg/HCTZ 25 mg, in patients whose blood pressure was not sufficiently controlled. At endpoint, metabolic parameters (total cholesterol, triglycerides, LDL, HDL, glucose, insulin) were not significantly altered in either treatment group. Most frequent adverse events under monotherapy (moexipril/atenolol) were asthenia (5.3/13.0%), headache (13.2/21.7%), cough (7.9/6.5%), pharyngitis (21.1/8.7%) and peripheral oedema (5.3/13.0%). Overall at least one AE was reported in 66% of the patients treated with moexipril and in 78% of those treated with atenolol. Reduction of SSBP/SDBP at endpoint was 14.7 +/- 1.9/10.0 +/- 1.1 and 8.7 +/- 1.9/8.4 +/- 1.1 mmHg after treatment with moexipril and atenolol, respectively. The results showed that moexipril and atenolol are equally effective in reducing blood pressure without adversely affecting blood lipids and carbohydrate metabolism.

Beta-blockers inhibit the modification of low-density lipoproteins by sodium hypochlorite in vitro

The effect of beta-blockers (alprenolol, oxprenolol, atenolol, acebutolol) and the non-steroidal anti-inflammatory drug, diclofenac, on modification of low-density lipoproteins (LDL) by sodium hypochlorite (NaOCl) was investigated in vitro. Beta-blockers and diclofenac inhibit the formation of thiobarbituric acid reactive substances in LDL modified by NaOCl. Beta-blockers, but not diclofenac, inhibit the hypochlorite-induced aggregation of LDL which was determined by photon correlation spectroscopy. The intracellular accumulation of cholesterol esters in J774 macrophages is inhibited by addition of beta-blockers, but not diclofenac, to LDL prior to the addition of NaOCl. The modification inhibiting effect of beta-blockers is inversely correlated to the binding capabilities of these substances to LDL which were assessed by laser electrophoresis. Inhibition of LDL modification in vivo by beta-blockers may reduce the risk of atherosclerosis and, therefore, compensate for the cholesterol-raising effect of these drugs in human plasma.

A 5-year prospective, observational study of the withdrawal of antihypertensive treatment in elderly people

OBJECTIVES

To observe blood pressure, cardiovascular events, and total mortality after withdrawing antihypertensive treatment for elderly patients.

DESIGN

Multicentre observational study.

SETTING

Sweden. A 5-year follow-up of 333 elderly hypertensive patients, aged 70-84 years (mean age 75.2 +/- SD 3.8 years, 68% females). In all, 74 out of the 333 patients (22%) died during the study period.

METHOD

After withdrawal of the antihypertensive therapy, all patients started in the untreated state and during the 5-year follow-up they could then either remain in the untreated state, or be reverted to blood-pressure-lowering drug treatment because of hypertension or other diseases, e.g. angina pectoris, oedema, congestive heart failure, etc.

RESULTS

The probability of remaining without treatment for 5 years was estimated to be 20%. During the state of no treatment the patients had a lower total mortality risk than that of the general Swedish population, matched for age and sex. They also had a lower risk of cardiovascular events than those in the treated states. Markers indicating a successful withdrawal were monotherapy in low doses and relatively low blood pressure before withdrawal.

CONCLUSION

These results suggest that with frequent check-ups, withdrawal of antihypertensive therapy in the elderly can be tried without increased risk of cardiovascular events.

Doxazosin withdrawal and ambulatory blood pressure monitoring in normotensive subjects

The effect of doxazosin withdrawal on normotensive subjects was examined by ambulatory blood pressure monitoring (ABPM) during twenty-four hours. Eight normotensive volunteers were treated with doxazosin for four weeks. ABPM was done the day before withdrawal and on the second and seventh days after withdrawal. The average systolic and diastolic BP were not altered by doxazosin withdrawal either on day 2 or day 7, but pulse rate (PR) decreased on day 2 and day 7. Daytime PR decreased on day 2, but both daytime and nighttime PR decreased on day 7. On withdrawal of doxazosin, the plasma norepinephrine concentration decreased and the plasma renin activity tended to decrease. Neither overshooting hypertension nor cardiovascular event was related to doxazosin withdrawal was observed. It is concluded that, in normotensive subjects, discontinuation of doxazosin may result in bradycardia without hypotension or signs of withdrawal syndrome.

The association of antihypertensive treatment patterns and adverse lipid effects in population-based studies

We investigated the relationship between antihypertensive drug treatment of hypertensives and their mean serum lipid concentrations in population based studies in Germany. Data from three surveys (Luebeck Blood Pressure Study (LBS) of 1984, MONICA Augsburg Survey I of 1984/85, MONICA Augsburg Survey II of 1989/90), obtained on random samples of the population aged 25-64 years, were used for cross-sectional analyses. Moreover, prospective analyses were carried out on participants of the MONICA Augsburg cohort study of 1987/88 (3-year-follow-up of the MONICA Survey I). Blood pressure, non-fasting serum total cholesterol and HDL-cholesterol, and body height and weight were measured under strictly standardized conditions. Interview data were available on medical history including medication use, and on smoking and alcohol consumption. In cross-sectional and prospective analyses treated male and female hypertensives in each population had significantly lower crude mean HDL-C concentrations than untreated hypertensives, borderliners, or normotensives. Differences in mean HDL-C between untreated and treated hypertensives were attenuated but still significant after control of confounders and ranged from 1.8 to 6.1 mg/dl (i.e. in relative terms, -3.4 to -12.9%) in men and from 3.6 to 9.4 mg/dl (-5.7 to -14.9%) in women. By contrast, crude and multivariate associations of antihypertensive treatment with non-HDL-C (total minus HDL-C) levels were inconsistent and not significant. The inverse association of drug therapy with HDL-C was confirmed by prospective analyses in the MONICA cohort study supporting a causal relationship. Treatment patterns in a community (prevalence of prescribed drug classes) correlated with the magnitude and significance of HDL-C effects.(ABSTRACT TRUNCATED AT 250 WORDS)

Multiple metabolic syndrome: aspects of genetic epidemiology and molecular genetics

Epidemiological studies have documented the association between cardiovascular disease and high blood pressure, dyslipidaemia, impaired glucose tolerance, non-insulin-dependent diabetes mellitus (NIDDM), and central obesity. In fact, several of these abnormalities, often all of them, can be identified in the very same individuals, constituting the entity of the multiple metabolic syndrome. Furthermore, many of these abnormalities seem to run in families. These findings raise important questions about the genetic epidemiology of the disease and about the molecular genetic background of the most likely common nominator of this syndrome, namely insulin resistance. Therapeutic actions must also be carefully considered to avoid the encouragement of some abnormalities while treating others.

Risk-benefit aspects of antihypertensive drugs

Several long term trials using traditional antihypertensive therapy with diuretics and beta-blockers have shown that antihypertensive therapy reduces the overall risk of cardiovascular complications. However, even after several years of therapy the cardiovascular risk in hypertensive patients cannot be lowered to that in the normotensive population. Antihypertensive therapy can reduce the incidence of cerebrovascular complications in patients with hypertension by about 65%. However, the effect of such therapy in preventing coronary events has been disappointing, as these events are 3 to 4 times more common than cerebrovascular complications in hypertensive patients. It is now apparent that adverse pharmacological effects of diuretics and beta-blockers on lipid metabolism persist for many years. Thus, treatment with these agents constitutes a new risk factor for coronary heart disease and may, at least in part, explain the failure of traditional antihypertensive therapy to reduce the incidence of myocardial infarction and sudden death as effectively as that of cerebrovascular accidents. On the other hand, titration of these antihypertensive agents to the lowest possible dose in order to avoid metabolic alterations and subjective adverse effects has frequently resulted in the administration of subtherapeutic doses, particularly for hydrochlorothiazide. Until comparative long term clinical trials with older and newer antihypertensive agents and morbidity and mortality as end-points are completed, the debate on first-line drugs for antihypertensive treatment will not be satisfactorily resolved.

Hypertension, plasma lipids and antihypertensive drugs

Treatment of hypertension is quite effective in preventing cerebrovascular disease. Morbidity and mortality from coronary heart disease, the major complications of high blood pressure are not, however, generally affected when mild to moderate hypertension is treated with antihypertensive drugs. This is probably owing to the multifactorial nature of atherosclerosis, the main cause of coronary heart disease. For example, dyslipidemias and other risk factors are very common among hypertensive patients. Prevention of coronary heart disease among hypertensive subjects is possible only by intervening in the many contributory risks. Non-pharmacological hypolipidemic treatments such as adequate nutrition and exercise are positive steps in the treatment of all hypertensive patients. The role of various antihypertensive agents should also be carefully considered. The associations between hypertension, several metabolic abnormalities, development of organ complications and various antihypertensive drugs should be explored in detail.