Optimal timing for antihypertensive dosing: focus on valsartan

Evening versus morning dosing regimen drug therapy for hypertension

BACKGROUND

Variation in blood pressure levels display circadian rhythms. Complete 24-hour blood pressure control is the primary goal of antihypertensive treatment and reducing adverse cardiovascular outcomes is the ultimate aim. This is an update of the review first published in 2011.

OBJECTIVES

To evaluate the effectiveness of administration-time-related effects of once-daily evening versus conventional morning dosing antihypertensive drug therapy regimens on all-cause mortality, cardiovascular mortality and morbidity, total adverse events, withdrawals from treatment due to adverse effects, and reduction of systolic and diastolic blood pressure in people with primary hypertension.

SEARCH METHODS

We searched the Cochrane Hypertension Specialised Register via Cochrane Register of Studies (17 June 2022), Cochrane Central Register of Controlled Trials (CENTRAL) (Issue 6, 2022); MEDLINE, MEDLINE In-Process and MEDLINE Epub Ahead of Print (1 June 2022); Embase (1 June 2022); ClinicalTrials.gov (2 June 2022); Chinese Biomedical Literature Database (CBLD) (1978 to 2009); Chinese VIP (2009 to 7 August 2022); Chinese WANFANG DATA (2009 to 4 August 2022); China Academic Journal Network Publishing Database (CAJD) (2009 to 6 August 2022); Epistemonikos (3 September 2022) and the reference lists of relevant articles. We applied no language restrictions.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing the administration-time-related effects of evening with morning dosing monotherapy regimens in people with primary hypertension. We excluded people with known secondary hypertension, shift workers or people with white coat hypertension.

DATA COLLECTION AND ANALYSIS

Two to four review authors independently extracted data and assessed trial quality. We resolved disagreements by discussion or with another review author. We performed data synthesis and analyses using Review Manager Web for all-cause mortality, cardiovascular mortality and morbidity, serious adverse events, overall adverse events, withdrawals due to adverse events, change in 24-hour blood pressure and change in morning blood pressure. We assessed the certainty of the evidence using GRADE. We conducted random-effects meta-analysis, fixed-effect meta-analysis, subgroup analysis and sensitivity analysis.

MAIN RESULTS

We included 27 RCTs in this updated review, of which two RCTs were excluded from the meta-analyses for lack of data and number of groups not reported. The quantitative analysis included 25 RCTs with 3016 participants with primary hypertension. RCTs used angiotensin-converting enzyme inhibitors (six trials), calcium channel blockers (nine trials), angiotensin II receptor blockers (seven trials), diuretics (two trials), α-blockers (one trial), and β-blockers (one trial). Fifteen trials were parallel designed, and 10 trials were cross-over designed. Most participants were white, and only two RCTs were conducted in Asia (China) and one in Africa (South Africa). All trials excluded people with risk factors of myocardial infarction and strokes. Most trials had high risk or unclear risk of bias in at least two of several key criteria, which was most prominent in allocation concealment (selection bias) and selective reporting (reporting bias). Meta-analysis showed significant heterogeneity across trials. No RCTs reported on cardiovascular mortality and cardiovascular morbidity. There may be little to no differences in all-cause mortality (after 26 weeks of active treatment: RR 0.49, 95% CI 0.04 to 5.42; RD 0, 95% CI -0.01 to 0.01; very low-certainty evidence), serious adverse events (after 8 to 26 weeks of active treatment: RR 1.17, 95% CI 0.53 to 2.57; RD 0, 95% CI -0.02 to 0.03; very low-certainty evidence), overall adverse events (after 6 to 26 weeks of active treatment: RR 0.89, 95% CI 0.67 to 1.20; I² = 37%; RD -0.02, 95% CI -0.07 to 0.02; I² = 38%; very low-certainty evidence) and withdrawals due to adverse events (after 6 to 26 weeks active treatment: RR 0.76, 95% CI 0.47 to 1.23; I² = 0%; RD -0.01, 95% CI -0.03 to 0; I² = 0%; very low-certainty evidence), but the evidence was very uncertain.

AUTHORS' CONCLUSIONS

Due to the very limited data and the defects of the trials' designs, this systematic review did not find adequate evidence to determine which time dosing drug therapy regimen has more beneficial effects on cardiovascular outcomes or adverse events. We have very little confidence in the evidence showing that evening dosing of antihypertensive drugs is no more or less effective than morning administration to lower 24-hour blood pressure. The conclusions should not be assumed to apply to people receiving multiple antihypertensive drug regimens.

The effect of bedtime versus morning dosing of antihypertensive drugs on the cardiovascular outcomes: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND AND OBJECTIVE

Antihypertensive drugs are one of the most effective strategies to prevent disability and mortality; however, there have been contradictory findings about the best dosing time for antihypertensive drugs. Therefore, we aim to evaluate the effect of bedtime versus morning dosing of antihypertensive drugs on cardiovascular outcomes.

METHODS

We synthesized randomized controlled studies (RCTs) from the Web of Science, SCOPUS, EMBASE, PubMed, and CENTRAL until 13 October 2022. The risk ratio (RR) for dichotomous outcomes with the corresponding 95% confidence interval (CI) was used. The study protocol was registered in PROSPERO with ID: CRD42022368612.

RESULTS

Five RCTs with 59 200 participants were included. Bedtime dosing was significantly associated with less incidence of myocardial infarction (MI) [RR: 0.80 with 95% CI (0.70-0.91), P = 0.0007] compared with morning dosing; however, there was no statistically significant difference between bedtime and morning dosing, regarding all-cause mortality [RR: 0.77 with 95% CI (0.51-1.16), P = 0.21], cardiovascular mortality [RR: 0.65 with 95% CI (0.35-1.21), P = 0.17], major adverse cardiac events (MACE) [RR: 0.79 with 95% CI (0.56-1.10), P = 0.16], heart failure [RR: 0.68 with 95% CI (0.42-1.09), P = 0.11], cerebrovascular accidents [RR: 0.80 with 95% CI (0.53-1.22), P = 0.30], coronary revascularization [RR: 0.79 with 95% CI (0.50-1.24), P = 0.30}, and angina [RR: 0.91 with 95% CI (0.55-1.50), P = 0.70].

CONCLUSION

Evidence about the comparative efficacy of bedtime versus morning dosing of antihypertensives is still uncertain. However, bedtime dosing significantly reduced MI, which warrants more robust RCTs to validate.

Dosing time optimization of antihypertensive medications by including the circadian rhythm in pharmacokinetic-pharmacodynamic models

Blood pressure (BP) follows a circadian variation, increasing during active hours, showing a small postprandial valley and a deeper decrease during sleep. Nighttime reduction of 10–20% relative to daytime BP is defined as a dipper pattern, and a reduction of less than 10%, as a non-dipper pattern. Despite this BP variability, hypertension’s diagnostic criteria and therapeutic objectives are usually based on BP average values. Indeed, studies have shown that chrono-pharmacological optimization significantly reduces long-term cardiovascular risk if a BP dipper pattern is maintained. Changes in the effect of antihypertensive medications can be explained by circadian variations in their pharmacokinetics (PK) and pharmacodynamics (PD). Nevertheless, BP circadian variation has been scarcely included in PK-PD models of antihypertensive medications to date. In this work, we developed PK-PD models that include circadian rhythm to find the optimal dosing time (Ta) of first-line antihypertensive medications for dipper and non-dipper patterns. The parameters of the PK-PD models were estimated using global optimization, and models were selected according to the lowest corrected Akaike information criterion value. Simultaneously, sensitivity and identifiability analysis were performed to determine the relevance of the parameters and establish those that can be estimated. Subsequently, Ta parameters were optimized to maximize the effect on BP average, BP peaks, and sleep-time dip. As a result, all selected models included at least one circadian PK component, and circadian parameters had the highest sensitivity. Furthermore, Ta with which BP>130/80 mmHg and a dip of 10–20% are achieved were proposed when possible. We show that the optimal Ta depends on the therapeutic objective, the medication, and the BP profile. Therefore, our results suggest making chrono-pharmacological recommendations in a personalized way.

Extent of asleep blood pressure reduction by hypertension medications is ingestion-time dependent: Systematic review and meta-analysis of published human trials

Combined evidence of published prospective outcome trials and meta-analyses substantiate elevated asleep blood pressure (BP) and blunted sleep-time relative BP decline (non-dipping), regardless of wake-time office BP and awake or 24 h BP means, are jointly the most highly significant independent prognostic markers of cardiovascular disease (CVD) risk and worthy therapeutic targets for prevention. Nonetheless, current guidelines continue to recommend the diagnosis of hypertension, when based on ambulatory BP monitoring (ABPM), rely, solely, on either the 24 h or "daytime" BP means. They also fail to recommend the time to treat patients. We conducted a systematic review of published human trials regarding ingestion-time differences in the effects of hypertension medications on asleep BP and sleep-time relative BP decline. Some 62 such trials published between 1992 and 2020, totaling 6120 hypertensive persons, evaluated 21 different single and 8 dual-fixed combination therapies. The vast (82.3%) majority of the trials substantiate the bedtime/evening vs. upon-waking/morning treatment schedule produces statistically significant better clinical benefits, including enhanced reduction of asleep systolic BP by an average 5.17 mmHg (95%CI [4.04, 6.31], P < 0.001 between treatment-time groups) without inducing sleep-time hypotension, reduced prevalence of the high CVD risk non-dipper 24 h BP pattern, improved kidney function, and reduced cardiac pathology. Furthermore, systematic and comprehensive review of the ABPM-based literature published the past 29 years reveals no single study that reported significantly better benefits of the most recommended, yet unjustified by medical evidence, morning hypertension treatment-time scheme.

Circadian Dysregulation: The Next Frontier in Obstructive Sleep Apnea Research

OBJECTIVE

To review the effects of the circadian clock on homeostasis, the functional interaction between the circadian clock and hypoxia-inducible factors, and the role of circadian dysregulation in the progression of cardiopulmonary disease in obstructive sleep apnea (OSA).

DATA SOURCES

The MEDLINE database was accessed through PubMed.

REVIEW METHODS

A general review is presented on molecular pathways disrupted in OSA, circadian rhythms and the role of the circadian clock, hypoxia signaling, crosstalk between the circadian and hypoxia systems, the role of the circadian clock in cardiovascular disease, and implications for practice. Studies included in this State of the Art Review demonstrate the potential contribution of the circadian clock and hypoxia in animal models or human disease.

CONCLUSIONS

Molecular crosstalk between the circadian clock and hypoxia-inducible factors has not been evaluated in disease models of OSA.

IMPLICATIONS FOR PRACTICE

Pediatric OSA is highly prevalent and, if left untreated, may lead to cardiopulmonary sequelae. Changes in inflammatory markers that normally demonstrate circadian rhythmicity are also seen among patients with OSA. Hypoxia-inducible transcription factors interact with core circadian clock transcription factors; however, the interplay between these pathways has not been elucidated in the cardiopulmonary system. This gap in knowledge hinders our ability to identify potential biomarkers of OSA and develop alternative therapeutic strategies. A deeper understanding of the mechanisms by which OSA impinges on clock function and the impact of clock dysregulation on the cardiopulmonary system may lead to future advancements for the care of patients with OSA. The aim of this review is to shed light on this important clinical topic.

Bedtime Blood Pressure Chronotherapy Significantly Improves Hypertension Management

Consistent evidence of numerous studies substantiates the asleep blood pressure (BP) mean derived from ambulatory BP monitoring (ABPM) is both an independent and a stronger predictor of cardiovascular disease (CVD) risk than are daytime clinic BP measurements or the ABPM-determined awake or 24-hour BP means. Hence, cost-effective adequate control of sleep-time BP is of marked clinical relevance. Ingestion time, according to circadian rhythms, of hypertension medications of 6 different classes and their combinations significantly improves BP control, particularly sleep-time BP, and reduces adverse effects.

Time of administration important? Morning versus evening dosing of valsartan

Objective:

Studies suggest that bedtime dosing of an angiotensin-converting enzyme (ACE)-inhibitor or angiotensin receptor blocker shows a more sustained and consistent 24-h antihypertensive profile, including greater night-time blood pressure (BP) reduction. We compared the antihypertensive effects of morning (a.m.) and evening (p.m.) dosing of valsartan on 24-h BP.

Methods:

This 26-week, multicentre, randomized, double-blind study evaluated the efficacy and safety of valsartan 320 mg, dosed a.m. or p.m., versus lisinopril 40 mg (a.m.), a long-acting ACE-inhibitor, in patients with grade 1–2 hypertension and at least one additional cardiovascular risk factor. Patients (n = 1093; BP = 156 ± 11/91 ± 8 mmHg; 62 years, 56% male, 99% white) received (1 : 1 : 1) valsartan 160 mg a.m. or p.m. or lisinopril 20 mg a.m. for 4 weeks, then force-titrated to double the initial dose for 8 weeks. At Week 12, hydrochlorothiazide (HCTZ) 12.5 mg was added for 14 weeks if office BP was more than 140/90 mmHg and/or ambulatory BP more than 130/80 mmHg.

Results:

Mean 24-h ambulatory SBP change from baseline to Weeks 12 and 26 was comparable between valsartan a.m. (–10.6 and –13.3 mmHg) and p.m. (–9.8 and –12.3 mmHg) and lisinopril (–10.7 and –13.7 mmHg). There was no benefit of valsartan p.m. versus a.m. on night-time BP, early morning BP and morning BP surge. Evening dosing also did not improve BP lowering in patients requiring add-on HCTZ or in nondippers at baseline. All treatments were well tolerated.

Conclusion:

Once-daily dosing of valsartan 320 mg results in equally effective 24-h BP efficacy, regardless of dosing time.

Trial Registration:

ClinicalTrials.gov Identifier: NCT00241124.

Chronotherapy with conventional blood pressure medications improves management of hypertension and reduces cardiovascular and stroke risks

Correlation between blood pressure (BP) and target organ damage, vascular risk and long-term patient prognosis is greater for measurements derived from around-the-clock ambulatory BP monitoring than in-clinic daytime ones. Numerous studies consistently substantiate the asleep BP mean is both an independent and a much better predictor of cardiovascular disease (CVD) risk than either the awake or 24 h means. Sleep-time hypertension is much more prevalent than suspected, not only in patients with sleep disorders, but also among those who are elderly or have type 2 diabetes, chronic kidney disease or resistant hypertension. Hence, cost-effective adequate control of sleep-time BP is of marked clinical relevance. Ingestion time, according to circadian rhythms, of hypertension medications of six different classes and their combinations significantly affects BP control, particularly sleep-time BP, and adverse effects. For example, because the high-amplitude circadian rhythm of the renin-angiotensin-aldosterone system activates during nighttime sleep, bedtime vs. morning ingestion of angiotensin-converting enzyme inhibitors and angiotensin receptor blockers better reduces the asleep BP mean, with additional benefit, independent of medication terminal half-life, of converting the 24 h BP profile into more normal dipper patterning. The MAPEC (Monitorización Ambulatoria para Predicción de Eventos Cardiovasculares) study, first prospective randomized treatment-time investigation designed to test the worthiness of bedtime chronotherapy with ⩾1 conventional hypertension medications so as to specifically target attenuation of asleep BP, demonstrated, relative to conventional morning therapy, 61% reduction of total CVD events and 67% decrease of major CVD events, that is, CVD death, myocardial infarction, and ischemic and hemorrhagic stroke. The MAPEC study, along with other earlier conducted less refined trials, documents the asleep BP mean is the most significant prognostic marker of CVD morbidity and mortality; moreover, it substantiates attenuation of the asleep BP mean by a bedtime hypertension treatment strategy entailing the entire daily dose of ⩾1 hypertension medications significantly reduces CVD risk in both general and more vulnerable hypertensive patients, that is, those diagnosed with chronic kidney disease, diabetes and resistant hypertension.

An agent-based model of cellular dynamics and circadian variability in human endotoxemia

As cellular variability and circadian rhythmicity play critical roles in immune and inflammatory responses, we present in this study an agent-based model of human endotoxemia to examine the interplay between circadian controls, cellular variability and stochastic dynamics of inflammatory cytokines. The model is qualitatively validated by its ability to reproduce circadian dynamics of inflammatory mediators and critical inflammatory responses after endotoxin administration in vivo. Novel computational concepts are proposed to characterize the cellular variability and synchronization of inflammatory cytokines in a population of heterogeneous leukocytes. Our results suggest that there is a decrease in cell-to-cell variability of inflammatory cytokines while their synchronization is increased after endotoxin challenge. Model parameters that are responsible for IκB production stimulated by NFκB activation and for the production of anti-inflammatory cytokines have large impacts on system behaviors. Additionally, examining time-dependent systemic responses revealed that the system is least vulnerable to endotoxin in the early morning and most vulnerable around midnight. Although much remains to be explored, proposed computational concepts and the model we have pioneered will provide important insights for future investigations and extensions, especially for single-cell studies to discover how cellular variability contributes to clinical implications.

Administration-time differences in effects of hypertension medications on ambulatory blood pressure regulation

Specific features of the 24-h blood pressure (BP) pattern are linked to progressive injury of target tissues and risk of cardiovascular disease (CVD) events. Several studies have consistently shown an association between blunted asleep BP decline and risk of fatal and nonfatal CVD events. Thus, there is growing focus on ways to properly control BP during nighttime sleep as well as during daytime activity. One strategy, termed chronotherapy, entails the timing of hypertension medications to endogenous circadian rhythm determinants of the 24-h BP pattern. Significant and clinically meaningful treatment-time differences in the beneficial and/or adverse effects of at least six different classes of hypertension medications, and their combinations, are now known. Generally, calcium channel blockers (CCBs) are more effective with bedtime than morning dosing, and for dihydropyridine derivatives bedtime dosing significantly reduces risk of peripheral edema. The renin-angiotensin-aldosterone system is highly circadian rhythmic and activates during nighttime sleep. Accordingly, evening/bedtime ingestion of the angiotensin-converting enzyme inhibitors (ACEIs) benazepril, captopril, enalapril, lisinopril, perindopril, quinapril, ramipril, spirapril, trandolapril, and zofenopril exerts more marked effect on the asleep than awake systolic (SBP) and diastolic (DBP) BP means. Likewise, the bedtime, in comparison with morning, ingestion schedule of the angiotensin-II receptor blockers (ARBs irbesartan, olmesartan, telmisartan, and valsartan exerts greater therapeutic effect on asleep BP, plus significant increase in the sleep-time relative BP decline, with the additional benefit, independent of drug terminal half-life, of converting the 24-h BP profile into a more normal dipping pattern. This is the case also for the bedtime versus upon-awakening regimen of combination ARB-CCB, ACEI-CCB, and ARB-diuretic medications. The chronotherapy of conventional hypertension medications constitutes a new and cost-effective strategy for enhancing the control of daytime and nighttime SBP and DBP levels, normalizing the dipping status of their 24-h patterning, and potentially reducing the risk of CVD events and end-organ injury, for example, of the blood vessels and tissues of the heart, brain, kidney, and retina.

Evening versus morning dosing regimen drug therapy for hypertension

BACKGROUND

Variation in blood pressure levels display circadian rhythms. The morning surge in blood pressure is known to increase the risk of myocardial events in the first several hours post awakening. A systematic review of the administration-time-related-effects of evening versus morning dosing regimen of antihypertensive drugs in the management of patients with primary hypertension has not been conducted.

OBJECTIVES

To evaluate the administration-time-related-effects of antihypertensive drugs administered as once daily monotherapy in the evening versus morning administration regimen on all cause mortality, cardiovascular morbidity and reduction of blood pressure in patients with primary hypertension.

SEARCH STRATEGY

We searched Cochrane CENTRAL on Ovid (4th Quarter 2009), Ovid MEDLINE (1950 to October 2009), EMBASE (1974 to October 2009), the Chinese Biomedical literature database (1978 to 2009) and the reference lists of relevant articles. No language restrictions were applied.

SELECTION CRITERIA

Randomized controlled trials comparing the administration-time-related effects of evening with morning dosing monotherapy regimens in patients with primary hypertension were included. Patients with known secondary hypertension, shift workers or white coat hypertension were excluded.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data and assessed trial quality. Disagreements were resolved by discussion or a third reviewer. Data synthesis and analysis were done using RevMan 5.1. Random effects meta-analysis and sensitivity analysis were conducted.

MAIN RESULTS

21 randomized controlled trials (RCTs) in 1,993 patients with primary hypertension met the inclusion criteria for this review - ACEIs (5 trials), CCBs (7 trials), ARBs (6 trials), diuretics (2 trials), alpha-blockers (1 trial), and beta-blockers (1 trial). Meta-analysis showed significant heterogeneity across trials.No RCT reported on all cause mortality, cardiovascular mortality, cardiovascular morbidity and serious adverse events.There was no statistically significant difference for overall adverse events (RR=0.78, 95%CI: 0.37 to 1.65) and withdrawals due to adverse events (RR=0.53, 95%CI: 0.26 to 1.07).No significant differences were noted for morning SBP (-1.62 mm Hg, 95% CI: -4.19 to 0.95) and morning DBP (-1.21 mm Hg, 95% CI: -3.28 to 0.86); but 24-hour BP (SBP: -1.71 mm Hg, 95% CI: -2.78 to -0.65; DBP: -1.38 mm Hg, 95% CI: -2.13 to -0.62) showed a statistically significant difference.

AUTHORS' CONCLUSIONS

No RCT reported on clinically relevant outcome measures - all cause mortality, cardiovascular morbidity and morbidity. There were no significant differences in overall adverse events and withdrawals due to adverse events among the evening versus morning dosing regimens. In terms of BP lowering efficacy, for 24-hour SBP and DBP, the data suggests that better blood pressure control was achieved with bedtime dosing than morning administration of antihypertensive medication, the clinical significance of which is not known.

Circadian rhythms in blood pressure regulation and optimization of hypertension treatment with ACE inhibitor and ARB medications

Specific features of the 24 h-blood pressure (BP) pattern are linked to the progressive injury of target tissues and risk of cardiac and cerebrovascular events. Studies have consistently shown an association between blunted asleep BP decline and increased incidence of fatal and nonfatal cardiovascular events. Thus, there is growing interest in how to achieve better BP control during nighttime sleep in addition to during daytime activity, according to the particular requirements of each hypertension patient. One approach takes into consideration the endogenous circadian rhythm-determinants of the 24-h BP pattern, especially, the prominent day-night variation of the renin-angiotensin-aldosterone system, which activates during nighttime sleep. A series of clinical studies have demonstrated a different effect of the angiotensin-converting enzyme (ACE) inhibitors benazepril, captopril, enalapril, lisinopril, perindopril, quinapril, ramipril, spirapril, and trandolapril when routinely ingested in the morning vs. the evening. In most cases, the evening schedule exerts a more marked effect on the asleep than awake BP means. Similarly, a once-daily evening, in comparison to morning, ingestion schedule of the angiotensin receptor blockers (ARBs) irbesartan, olmesartan, telmisartan, and valsartan exerts greater therapeutic effect on asleep BP, plus significant increase in the sleep-time relative BP decline, with normalization of the circadian BP profile toward a more dipping pattern, independent of drug terminal half-life. Chronotherapy, the timing of treatment to body rhythms, is a cost-effective means of both individualizing and optimizing the treatment of hypertension through normalization of the 24-h BP level and profile, and it may constitute an effective option to reduce cardiovascular risk.

Chronotherapy in Nigerian hypertensives

OBJECTIVES

Hypertension continues to cause significant morbidity and mortality worldwide, and the situation is worse in Blacks. Treatment has proved to be beneficial, but control has remained abysmal. Night-time chronotherapy is producing better control and outcome, but has only largely been tried in the West. This work attempts to see what benefits would emerge with night-time chronotherapy as compared with the current recommended morning intake of antihypertensives in an entirely African cohort.

METHODS

Ambulant grade 1 and 2 hypertensives attending our outpatient service were randomized after a washout period into morning or night-time ingestion groups. Drugs were tailored towards each patient's cardiovascular disease profile and reviewed to ensure control. They were comprehensively evaluated on enrolment and 12 weeks later.

RESULTS

Both groups were similar on all scores at baseline. After 12 weeks of treatment, the mean changes in diastolic blood pressure (DBP), mean arterial pressure (MAP), left ventricular posterior diameter (LVPWD) and left ventricular mass (LVM) were greater, to a statistically significant extent in the night-time group. The difference in the systolic blood pressure (SBP) and interventricular septum diameter (IVSD) tended to be greater in the same group but did not differ between the groups to a statistically significant extent.

CONCLUSION

Chronotherapeutic studies in the West recorded greater success with night-time ingestion which produced better control and a day-long profile. Generalization to other races was cautioned against until such observations could be replicated. We have shown that patients using their once-daily antihypertensives at night after 12 weeks recorded better reductions in SBP, DBP, MAP, LVPWD, IVSD and LVM. Since blood pressure problems run a worse course in Blacks, we recommend encouragement of night-time intake in those preferring it and suggest that in those requiring two or more drugs one should be taken at night.

Managing hypertension in obstructive sleep apnea: the interplay of continuous positive airway pressure, medication and chronotherapy

Hypertension is highly prevalent and usually uncontrolled among patients with obstructive sleep apnea despite multiple interventions, namely lifestyle modifications, use of antihypertensive drugs and continuous positive airway pressure application. Main prognosticators of the blood pressure (BP) reduction with continuous positive airway pressure therapy are high levels of BP, severity of apnea and daytime sleepiness. The long-term effect of continuous positive airway pressure on BP is still inconclusive, and compliance issues constitute a major limitation. There is no clear evidence for preference for a specific type of antihypertensive drug, and selection should primarily be guided by the patient's cardiometabolic profile and associated clinical conditions. Furthermore, as hypertensive patients with obstructive sleep apnea frequently exhibit a disturbed circadian BP pattern, chronotherapy emerges as a possible therapeutic supplement.

Persistent microalbuminuria after treatment with renin-angiotensin axis blockers: causes and results of treatment intensification

AIMS

The first phase of this study aimed to determine the causes of persistent microalbuminuria after treatment with renin-angiotensin axis (RAA) blocking drugs. In a second phase we tried to determine if strict control of blood pressure and intensive RAA blockade could induce remission or reduction of microalbuminuria in clinical (primary care) practice.

PATIENTS AND METHODS

The study included both diabetic patients and non-diabetic hypertensive patients treated with RAA drugs in the presence of microalbuminuria. 211 patients were recruited (mean age 66.6±11.3 years, 111 men, 117 were diabetic). In the first phase treatment was optimized at standard doses. In the second phase treatment was increased during a three months period to reach a blood pressure (BP) < 130/80 mmHg by adding other antihypertensive treatment and to obtain maximal RAA blockade using long-acting drugs, increased dosage, or adding further medication at night.

RESULTS

Initial mean BP was 141±16/81±11 mmHg. BP control was unsatisfactory (control of systolic blood pressure [SBP] 19.3%; diastolic blood pressure [DBP] 37.6%). Dosage of RAA blocking drugs was inadequate in 21% of patients. Only 27.4% of patients were taking antihypertensive drugs at night. 30.1% of patients took once daily short acting drugs. During the studymean SBP was reduced to 137±13 mmHg (p < .001) and DBP decreased to 79±10 mmHg (p < .001). Control of SBP improved to 24.5% and DBP control went to 44.4%. Mean microalbuminuria decreased from 64.4±47.0 mg/day to 50.1±53.0 mg/day (p < .001) and the prevalence of microalbuminuria was reduced to 59.1%.

CONCLUSIONS

Persistent microalbuminuria was associated with poor blood pressure control and inadequate drug dosage. Low frequency of administration of drugs at night and inappropriate once-daily pills intake were frequent. Strict control of blood pressure and intensive RAA blockade significantly reduced the prevalence of microalbuminuria.

Potential roles of melatonin and chronotherapy among the new trends in hypertension treatment

The number of well-controlled hypertensives is unacceptably low worldwide. Respecting the circadian variation of blood pressure, nontraditional antihypertensives, and treatment in early stages of hypertension are potential ways to improve hypertension therapy. First, prominent variations in circadian rhythm are characteristic for blood pressure. The revolutionary MAPEC (Ambulatory Blood Pressure Monitoring and Cardiovascular Events) study, in 3000 adult hypertensives investigates, whether chronotherapy influences the cardiovascular prognosis beyond blood pressure reduction per se. Second, melatonin, statins and aliskiren are hopeful drugs for hypertension treatment. Melatonin, through its scavenging and antioxidant effects, preservation of NO availability, sympatholytic effect or specific melatonin receptor activation exerts antihypertensive and anti-remodeling effects and may be useful especially in patients with nondipping nighttime blood pressure pattern or with nocturnal hypertension and in hypertensives with left ventricular hypertrophy (LVH). Owing to its multifunctional physiological actions, this indolamine may offer cardiovascular protection far beyond its hemodynamic benefit. Statins exert several pleiotropic effects through inhibition of small guanosine triphosphate-binding proteins such as Ras and Rho. Remarkably, statins reduce blood pressure in hypertensive patients and more importantly they attenuate LVH. Addition of statins should be considered for high-risk hypertensives, for hypertensives with LVH, and possibly for high-risk prehypertensive patients. The direct renin inhibitor, aliskiren, inhibits catalytic activity of renin molecules in circulation and in the kidney, thus lowering angiotensin II levels. Furthermore, aliskiren by modifying the prorenin conformation may prevent prorenin activation. At present, aliskiren should be considered in hypertensive patients not sufficiently controlled or intolerant to other inhibitors of renin-angiotensin system. Third, TROPHY (Trial of Preventing Hypertension) is the first pharmacological intervention for prehypertensive patients revealing that treatment with angiotensin II type 1 receptor blocker attenuates hypertension development and thus decreases the risk of cardiovascular events.

Causes and mechanisms of nondipping hypertension

Growing evidence indicates that nondippers have worsened cardiovascular outcomes than dippers. Ambulatory blood pressure monitoring with a lack of nocturnal BP fall (nondipping) have also been shown to be more closely associated with target organ damage and worsened cardiovascular outcome than in patients with essential hypertension with dipping pattern. The underlying pathogenetic mechanisms potentially linking nondipping with cardiovascular disease are not fully understood. There are multiple possible underlying pathophysiologic mechanisms in the impaired BP decline during the night. Extrinsic and intrinsic factors including abnormal neurohormonal regulation, lack of physical activity, nutritional factors such as increased dietary sodium intake, and smoking of tobacco have been implicated for blunted circadian rhythm of BP. Certain diseases such as diabetes and chronic renal diseases also affect the circadian BP rhythm. Currently, the clinical importance of nondipping is known well; however, the relationship between certain disease states and nondipping has not been fully explained yet. This paper will attempt to address to clarify the underlying basis for nondipping and the specific associations with various disease states.