Effects of time of day of treatment on ambulatory blood pressure pattern of patients with resistant hypertension

Patients with resistant hypertension present high prevalence of a non-dipper blood pressure pattern. Recent results indicate that non-dipping is related partly to the absence of 24-hour therapeutic coverage in patients treated with single morning doses. Accordingly, we investigated the impact of treatment time on the blood pressure pattern in 700 patients with resistant hypertension on the basis of clinic measurements who were studied by 48-hour ambulatory monitoring. Among them, 299 patients received all their medication on awakening, and 401 were taking > or =1 antihypertensive drug at bedtime. The percentage of patients with controlled ambulatory blood pressure was double in patients taking 1 drug at bedtime (P=0.008). Among the 578 patients with true resistant hypertension, subjects receiving 1 drug at bedtime showed a significant reduction in the 24-hour mean of systolic and diastolic blood pressure (3.1 and 1.6 mm Hg, respectively; P<0.011). This reduction was much more prominent during nighttime (5.1 and 3.0 mm Hg; P<0.001). Accordingly, the diurnal/nocturnal blood pressure ratio was significantly increased by 2.7 and the prevalence on non-dipping reduced (56.9 versus 81.9%; P<0.001) in patients taking 1 drug at bedtime. Compared with patients receiving all drugs on awakening, subjects with 1 drug at bedtime also showed significant reductions in the average values of glucose, cholesterol, fibrinogen, and urinary albumin excretion (P<0.011). In patients with resistant hypertension, pharmacological therapy should take into account when to treat with respect to the rest-activity cycle of each patient to improve control and to avoid the non-dipper pattern associated to higher cardiovascular risk.     

Chronotherapy with nifedipine GITS in hypertensive patients: improved efficacy and safety with bedtime dosing

BACKGROUND: Previous studies have shown that the circadian pattern of blood pressure (BP) remains unchanged after either morning or evening dosing of several calcium-channel blockers (CCBs), including amlodipine, isradipine, verapamil, nitrendipine, and cilnidipine. This trial investigated the administration-time dependent antihypertensive efficacy of the slow-release, once-a-day nifedipine gastrointestinal-therapeutic-system (GITS) formulation. METHODS: We studied 180 untreated hypertensives (86 men and 94 women), 52.5 +/- 10.7 years of age, randomly assigned to receive nifedipine (30 mg/day) as a monotherapy either upon awakening or at bedtime. BP was measured for 48 h before and after 8 weeks of treatment. RESULTS: The BP reduction after treatment was significantly larger with bedtime dosing mainly during night time sleep (P < 0.012). The number of patients with controlled ambulatory BP after treatment was greater with bedtime than morning treatment (P = 0.016). The baseline prevalence of nondipping was unaltered after ingestion of nifedipine on awakening, but reduced from 51 to 35% after bedtime dosing (P = 0.025). The morning surge of BP, a risk factor for stroke, was significantly reduced (P < 0.001) only after bedtime administration of nifedipine. Bedtime in comparison to awakening-time ingestion of nifedipine was also associated with a reduction in the incidence of edema from 13 to 1% (P < 0.001). CONCLUSIONS: The increased efficacy on ambulatory BP as well as the significantly reduced prevalence of edema after bedtime as compared to morning ingestion of nifedipine should be taken into account when prescribing this medication to patients with essential hypertension.     

Assessment of blood pressure control in hypertensive stroke survivors: an ambulatory blood pressure monitoring study

BACKGROUND: We compared the sensitivity of office blood pressure and ambulatory blood pressure monitoring recordings in evaluating the effectiveness of antihypertensive treatment and identified factors related to inadequate blood pressure control among hypertensive stroke survivors. METHODS: Office blood pressure and ambulatory blood pressure monitoring measurements were performed at 120+/-30 days after ictus in 187 first-ever consecutive hypertensive stroke survivors who were receiving blood pressure-lowering medications according to international guidelines. Handicap was assessed by the modified Rankin Scale. Blood pressure was regarded as controlled if office and daytime ambulatory systolic and diastolic blood pressure values were <140/90 and <135/85 mmHg, respectively. Patients were subclassified according to the degree of their nocturnal systolic blood pressure fall [(mean daytime values-mean night-time values)100/mean daytime values] as dippers (>or=10%), nondippers (>or=0% and <10%) and reverse dippers (<0%). RESULTS: Effective blood pressure control was documented in significantly (P<0.001) fewer patients using ambulatory blood pressure monitoring (32.1%) than those using office recordings (43.3%), whereas in 16% of the study population a masked lack of per-treatment blood pressure control (elevated ambulatory blood pressure in the presence of normal office blood pressure levels) was identified. The distribution of dipping patterns differed significantly (P=0.01) between controlled hypertensive individuals (normal office and ambulatory measurements) and patients with isolated ambulatory hypertension (dippers: 31.3 vs. 10.0%; nondippers:56.9 vs. 53.3%; reverse dippers: 11.8 vs. 36.7%). Logistic regression analysis revealed diabetes mellitus and functional independency (modified Rankin Scale score<2) as independent predictors of inadequate blood pressure control. CONCLUSION: Ambulatory blood pressure monitoring detects a substantial number of treated hypertensive stroke survivors with a masked lack of per-treatment blood pressure control, who present a higher prevalence of abnormal circadian blood pressure patterns (reverse dipping). Diabetes mellitus and poststroke functional independency are the main factors contributing to inadequate blood pressure control.     

Evaluation of the Antihypertensive Effect of Barnidipine, a Dihydropyridine Calcium Entry Blocker, as Determined by the Ambulatory Blood Pressure Level Averaged for 24 h, Daytime, and Nighttime

We evaluated the effect of barnidipine, a dihydropyridine calcium antagonist, administered once daily in the morning in a dose of 5, 10, or 15 mg on ambulatory blood pressure (BP) in 34 patients (51.3 ± 9.6 years). Hypertension was diagnosed based on the clinic BP. The patients were classified into groups according to the ambulatory BP: group 1, dippers with true hypertension; group 2, nondippers with true hypertension; group 3, dippers with false hypertension; and Group 4, nondippers with false hypertension. Barnidipine reduced the clinic systolic BP (SBP) and diastolic BP (DBP) in all groups and significantly reduced the average 24 h ambulatory BP (133.0 ± 16.5/90.7 ± 12.3 mm Hg v 119.7 ± 13.7/81.8 ± 10.3 mm Hg, P < .0001 for both SBP and DBP). Barnidipine significantly reduced the daytime ambulatory SBP in groups 1, 2, and 3, but not in group 4, and significantly reduced daytime ambulatory DBP in group 1 but not in groups 2, 3, and 4. Barnidipine significantly reduced the nighttime ambulatory SBP only in group 2 and the nighttime ambulatory DBP in groups 2 and 4. Once-a-day administration of barnidipine influenced 24 h BP on true hypertensives (the ratio of the trough to peak effect > 50%), but had minimal effect on low BP such as the nocturnal BP in dippers and the ambulatory BP in false hypertensives. These findings suggest that barnidipine can be used safely in patients with isolated clinic (“white coat”) hypertension and in those with dipping patterns of circadian BP variation whose nocturnal BP is low before treatment.     

Differing administration time-dependent effects of aspirin on blood pressure in dipper and non-dipper hypertensives

Aspirin is a potent antioxidative agent that reduces vascular production of superoxide, prevents angiotensin II-induced hypertension, and induces NO release. Low-dose aspirin administered at bedtime, but not on awakening, has also been shown to reduce blood pressure, possibly enhancing the nocturnal trough in NO production. Because endothelium-dependent vasodilation is blunted through a decrease in NO release in non-dipper compared with dipper patients, we compared the administration time-dependent influence of aspirin on ambulatory blood pressure in dipper and non-dipper hypertensive subjects. We studied 257 patients with mild hypertension (98 men and 159 women), 44.6+/-12.5 years of age, randomly assigned to receive 100 mg per day of aspirin either on awakening or at bedtime. Ambulatory blood pressure was measured for 48 hours at baseline and after 3 months of intervention. Blood pressure was slightly elevated after aspirin on awakening (increase of 1.5/1.0 mm Hg in the 24-hour mean of systolic/diastolic blood pressure; P<0.028). A highly significant blood pressure reduction was observed in patients who received aspirin at bedtime (decrease of 7.2/4.9 mm Hg in systolic/diastolic blood pressure; P<0.001). The reduction in nocturnal blood pressure mean was double in non-dippers (11.0/7.1 mm Hg) compared with dippers (5.5/3.3 mm Hg; P<0.001). This prospective trial corroborates the significant administration time-dependent effect of low-dose aspirin on blood pressure, mainly in non-dipper hypertensive patients. The timed administration of low-dose aspirin could thus provide a valuable approach, beyond prevention of cardiovascular disease, in the blood pressure control of patients with mild hypertension.     

An alpha-adrenergic blocker titrated by self-measured blood pressure recordings lowered blood pressure and microalbuminuria in patients with morning hypertension: the Japan Morning Surge-1 Study

BACKGROUND: The impact on microalbuminuria of strict treatment aimed at lowering of self-measured morning blood pressure using an adrenergic blockade is unclear. METHODS: We conducted an open-label multicenter trial, the Japan Morning Surge-1 Study, that enrolled 611 hypertensive patients, whose self-measured morning systolic blood pressure levels were more than 135 mmHg while taking antihypertensive drugs. These were randomly allocated to an experimental group, whose members received bedtime administration of 1-4 mg doxazosin (doxazosin group) or a control group whose members continued without any add-on medication (control group). The urinary albumin/creatinine ratio was investigated at the baseline and 6 months after the randomization. RESULTS: Both the morning and evening blood pressures and urinary albumin/creatinine ratio (-3.4 vs. 0.0 mg/gCr for urinary albumin/creatinine ratio; P < 0.001) were more markedly reduced in the doxazosin group than in the control group. This difference in the urinary albumin/creatinine ratio between the two groups was more marked in the patients with microalbuminuria (n = 238, -27.9 vs. -8.1 mg/gCr, P < 0.001). The reduction of urinary albumin/creatinine ratio was significantly associated with the use of doxazosin, and the change in all self-measured blood pressures (morning, evening, the average morning-evening), and these associations were independent of each other (P < 0.001). CONCLUSION: Adding a bedtime dose of an alpha-adrenergic blocker titrated by self-measured morning blood pressure in treated hypertensive patients with uncontrolled morning hypertension significantly reduced blood pressure and urinary albumin excretion rate, particularly in those with microalbuminuria.     

Treatment of non-dipper hypertension with bedtime administration of valsartan

BACKGROUND: Previous results have indicated that valsartan administration at bedtime, as opposed to upon wakening, may improve the diurnal: nocturnal ratio of blood pressure without loss in 24-h coverage and efficacy. OBJECTIVES: To investigate the administration time-dependent antihypertensive efficacy of valsartan in non-dipper patients. METHODS: We studied 148 non-dipper patients with grade 1-2 essential hypertension, aged 53.0+/-12.6 years, who were randomly assigned to receive valsartan (160 mg/day) as a monotherapy either on awakening or at bedtime. Blood pressure was measured every 20 min during the day and every 30 min at night for 48 consecutive hours before and after 3 months of treatment. Physical activity was simultaneously monitored every minute by wrist actigraphy to accurately calculate the diurnal and nocturnal means of blood pressure on a per subject basis. RESULTS: The significant blood pressure reduction after 3 months of valsartan (P<0.001) was similar for both treatment times (13.1 and 8.5 mmHg reduction in the 24-h mean of systolic and diastolic blood pressure with morning administration; 14.7 and 10.3 mmHg with bedtime administration; P>0.126 for treatment-time effect). The diurnal: nocturnal ratio of blood pressure was significantly increased only when valsartan was administered before bedtime, which resulted in 75% of the patients in this group reverting to dippers, a significant increase in the percentage of patients with controlled blood pressure over 24 h, and a reduction in urinary albumin excretion. CONCLUSIONS: In non-dipper hypertensive patients, dosing time with valsartan should be chosen at bedtime, for improved efficacy during the nocturnal resting hours, as well as the potential associated reduction in cardiovascular risk.     

Ambulatory blood pressure monitoring and clinical characteristics of the true and white-coat resistant hypertension

The resistant hypertension has been differentiated in true resistant hypertension and white-coat resistant hypertension by using ambulatory blood pressure monitoring. White-coat resistant hypertension was defined as high clinic blood pressure, despite triple treatment for at least 3 months, but day-time blood pressure values < 135/85 mmHg. The aim of this study was to evaluate the presence of different clinical characteristics between two types of resistant hypertension. The study group consisted of 49 patients with essential hypertension, resistant to an adequate and appropriate triple-drug therapy, that included a diuretic, with all 3 drugs prescribed in near maximal doses and that had persistently elevated clinic blood pressure (> 140/90 mm Hg), for at least 3 months. They represented the 2% of 2500 hypertensive outpatients that referred at our Hypertension Unit. Patients with white-coat resistant hypertension (n=19) were older (p<0.05) than those with true resistant hypertension (n=30). The sodium intake (p<0.05) and alcohol intake (p<0.05) were significantly higher in patients with true resistant hypertension than in those with white-coat resistant hypertension. The renin plasma activity and plasma aldosterone were higher (p<0.05) in patients with true resistant hypertension than in those with white-coat resistant hypertension with normal plasma electrolyte balance. There were no significant differences in mean values of office systolic and diastolic blood pressures between white coat resistant hypertensives and true resistant hypertensives (165+17 vs 172+28 and 98+12 vs 102+14 mmHg). Day-time and night-time ambulatory 24-h-systolic and diastolic blood pressures were significantly higher in the true resistant hypertensive patients when compared with white-coat resistant hypertensives (153+15 vs 124+10 mmHg and 97+9 vs 76+6 mmHg all p<0.001). Day-time and night-time ambulatory 24-h-heart rate were significantly higher in the true resistant hypertensive patients when compared with white-coat resistant hypertensives (79+11 vs 71+9 beats/min; p<0.01; 68+9 vs 60+6 beats/min, p<0.001). The ABP readings were analysed by a Fourier series with 4 harmonics. According to the runs test both two groups of patients showed a circadian rhythm for both systolic and diastolic blood pressure. The nocturnal fall in SBP, DBP and HR was not different in both groups of patients. In conclusion, our findings showed that true resistant hypertensive patients were characterized both by higher heart rate and higher plasma renin activity values as an expression of a possible increased sympathetic activity. Thus, the combination of ABPM with the assessment of the clinical characteristics allow to differentiate better the true drug-resistant hypertension from the white coat resistant hypertension.     

Insufficient duration of action of antihypertensive drugs mediates high blood pressure in the morning in hypertensive population: the Ohasama study

Blood pressure (BP) usually peaks in the morning. The circadian variation of the onset of cardiovascular disease mimics this circadian BP variation. To examine the determinants of the BP difference between the self-recorded BP in the morning (home BP) and daytime average ambulatory BP a cross sectional study was done in the general population of Ohasama, Japan. 1207 subjects > or = 20 years measured both home (more than 14 times) and ambulatory BPs (326 treated for hypertension and 881 untreated subjects), The prevalence of subjects with the systolic BP difference (home BP in the morning - daytime ambulatory BP) of > or = 10 mmHg (high morning BP) was 5.6% in untreated normotensives, 2.9% in untreated hypertensives, and 25.8% in treated hypertensives. This trend was also observed for diastolic pressure. Multiple regression analysis demonstrated that age, male sex, and use of antihypertensive drugs were positively associated and day-night difference of BP was negatively associated with the high morning BP, respectively. These results suggest an insufficient duration of antihypertensive action of widely used antihypertensive drugs in Japan from the 1980s to 1990s. The amplitude of the day-night difference of ambulatory BP in subjects with a high morning BP was lower (non-dipping) than that without high morning BP. The high morning BP is not necessarily accompanied by hypertension but might be mediated, at least in part, by an insufficient duration of action of antihypertensive drugs. The high morning BP accompanies so-called non-dipper pattern of circadian BP variation. An insufficient duration of action of drugs may partly mediate non-dipping in subjects with antihypertensive medication.     

INSUFFICIENT DURATION OF ACTION OF ANTIHYPERTENSIVE DRUGS MEDIATES HIGH BLOOD PRESSURE IN THE MORNINGIN HYPERTENSIVE POPULATION:THE OHASAMA STUDY

Blood pressure (BP) usually peaks in the morning. The circadian variation of the onset of cardiovascular disease mimics this circadian BP variation. To examine the determinants of the BP difference between the self-recorded BP in the morning (home BP) and daytime average ambulatory BP a cross sectional study was done in the general population of Ohasama, Japan. 1207 subjects ≥20 years measured both home (more than 14 times) and ambulatory BPs (326 treated for hypertension and 881 untreated subjects). The prevalence of subjects with the systolic BP difference (home BP in the morning?daytime ambulatory BP) of ≥10?mmHg (high morning BP) was 5.6% in untreated normotensives, 2.9% in untreated hypertensives, and 25.8% in treated hypertensives. This trend was also observed for diastolic pressure. Multiple regression analysis demonstrated that age, male sex, and use of antihypertensive drugs were positively associated and day-night difference of BP was negatively associated with the high morning BP, respectively. These results suggest an insufficient duration of antihypertensive action of widely used antihypertensive drugs in Japan from the 1980s to 1990s. The amplitude of the day-night difference of ambulatory BP in subjects with a high morning BP was lower (non-dipping) than that without high morning BP. The high morning BP is not necessarily accompanied by hypertension but might be mediated, at least in part, by an insufficient duration of action of antihypertensive drugs. The high morning BP accompanies so-called non-dipper pattern of circadian BP variation. An insufficient duration of action of drugs may partly mediate non-dipping in subjects with antihypertensive medication.     

AMBULATORY BLOOD PRESSURE MONITORING AND CLINICAL CHARACTERISTICS OF THE TRUE AND WHITE-COAT RESISTANT HYPERTENSION

The resistant hypertension has been differentiated in true resistant hypertension and white-coat resistant hypertension by using ambulatory blood pressure monitoring. White-coat resistant hypertension was defined as high clinic blood pressure, despite triple treatment for at least 3 months, but day-time blood pressure values < 135/85 mmHg. The aim of this study was to evaluate the presence of different clinical characteristics between two types of resistant hypertension.

The study group consisted of 49 patients with essential hypertension, resistant to an adequate and appropriate triple-drug therapy, that included a diuretic, with all 3 drugs prescribed in near maximal doses and that had persistently elevated clinic blood pressure (>140/90 mm Hg), for at least 3 months. They represented the 2% of 2500 hypertensive outpatients that referred at our Hypertension Unit. Patients with white-coat resistant hypertension (n=19) were older (p<0.05) than those with true resistant hypertension (n=30). The sodium intake (p<0.05) and alcohol intake (p<0.05) were significantly higher in patients with true resistant hypertension than in those with white-coat resistant hypertension. The renin plasma activity and plasma aldosterone were higher (p<0.05) in patients with true resistant hypertension than in those with white-coat resistant hypertension with normal plasma electrolyte balance. There were no significant differences in mean values of office systolic and diastolic blood pressures between white coat resistant hypertensives and true resistant hypertensives (165+17 vs 172+28 and 98+12 vs 102+14 mmHg).

Day-time and night-time ambulatory 24-h-systolic and diastolic blood pressures were significantly higher in the true resistant hypertensive patients when compared with white-coat resistant hypertensives (153+15 vs 124+10 mmHg and 97+9 vs 76+6 mmHg all p<0.001). Day-time and night-time ambulatory 24-h-heart rate were significantly higher in the true resistant hypertensive patients when compared with white-coat resistant hypertensives (79+11 vs 71+9 beats/min;p<0.01; 68+9 vs 60+6 beats/min. p<0.001). The ABP readings were analysed by a Fourier series with 4 harmonics. According to the runs test both two groups of patients showed a circadian rhythm for both systolic and diastolic blood pressure. The nocturnal fall in SBP, DBP and HR was not different in both groups of patients.

In conclusion, our findings showed that true resistant hypertensive patients were characterized both by higher heart rate and higher plasma renin activity values as an expression of a possible increased sympathetic activity. Thus, the combination of ABPM with the assessment of the clinical characteristics allow to differentiate better the true drug-resistant hypertension from the white coat resistant hypertension.     

White-Coat Resistant Hypertension

The aim of this study was to evaluate whether sustained hypertensives with high clinic blood pressure, despite multiple drug treatment, show a true resistant hypertension or a “white-coat effect,” and whether the pretreatment white-coat effect is maintained despite pharmacological therapy. The occurrence of resistant hypertension was determined in 250 consecutive essential hypertensives who had had an ambulatory blood pressure monitoring before treatment assignment. Twenty-seven of 250 hypertensives with persistently high clinic blood pressure despite 3 months of adequate pharmacological therapy underwent further ambulatory blood pressure monitoring. Using our internal standards, seven patients had a true resistant hypertension whereas 20 subjects showed a large white-coat effect (white-coat resistant hypertension), ie, high clinic blood pressure (>140/90) but “normal” ambulatory daytime (<139/90 mm Hg) and 24 h (135/85 mm Hg) blood pressure. Using other cutoff points for ambulatory blood pressure, 134/90 and 135/85 mm Hg for daytime blood pressure, 10 and 13 patients, respectively, were reclassified as true resistant hypertensives and 17 and 14, respectively, were white-coat resistant hypertensives. Interestingly, in white-coat resistant hypertensives the large differences between clinic and ambulatory daytime blood pressure (white-coat effect), recorded before treatment assignment, were not affected by drugs and remained constant over time. Left ventricular mass index in white-coat resistant hypertensives was significantly lower than in truly resistant hypertensives, suggesting that prognosis could differ between these groups. In this study, using either our internal standards or some other cutoffs reported in the literature, the white-coat phenomenon was an important cause of resistant hypertension. The use of ambulatory blood pressure monitoring in these patients may avoid misdiagnosis of resistant hypertension, unnecessary overtreatment, and expensive procedures to look for possible secondary hypertension.     

Decrease in urinary albumin excretion associated with the normalization of nocturnal blood pressure in hypertensive subjects

Previous results have indicated that valsartan administration at bedtime as opposed to on wakening improves the diurnal/nocturnal ratio of blood pressure without loss in efficacy and therapeutic coverage. We hypothesized that increasing this ratio could reduce microalbuminuria. We conducted a prospective, randomized, open-label, blinded endpoint trial on 200 previously untreated nonproteinuric patients with grade 1 to 2 essential hypertension, assigned to receive valsartan (160 mg/d) as a monotherapy either on awakening or at bedtime. Blood pressure was measured by ambulatory monitoring for 48 consecutive hours before and after 3 months of treatment. Physical activity was simultaneously monitored every minute by wrist actigraphy to accurately calculate the diurnal and nocturnal means of blood pressure on a per-subject basis. The significant blood pressure reduction after 3 months of therapy was similar for both treatment times. The diurnal/nocturnal blood pressure ratio was unchanged after valsartan on awakening, but significantly increased from 7.5 to 12.2 (P<0.001) when valsartan was administered at bedtime. Urinary albumin excretion was significantly reduced by 41% after bedtime treatment. This reduction was independent of the 24-hour blood pressure decrease but highly correlated with the decrease in nocturnal blood pressure and mainly with the increase in diurnal/nocturnal ratio (P<0.001). Bedtime valsartan administration improves the diurnal/nocturnal blood pressure ratio to a more dipper profile. This normalization of the circadian blood pressure pattern is associated with a significant decrease in urinary albumin excretion and plasma fibrinogen, and could thus reduce the increased cardiovascular risk in nondipper hypertensive patients.     

坎地沙坦时间治疗学对非杓型高血压的影响

目的观察坎地沙坦不同给药时间对非杓型高血压患者血压水平及血压昼夜节律的影响。方法选择经24h动态血压监测属于非杓型高血压的需要药物治疗的1级高血压患者106例,随机（电脑随机数字表法）分为A组（早晨7：00服药）和B组（晚上7：00服药）。两组均选用坎地沙坦4mg,用药8周后观察用药前后24h动态血压参数,比较两组血压昼夜节律的变化。结果两组治疗前后血压比较,24h收缩压、24h舒张压、白昼收缩压、白昼舒张压、夜问收缩压、夜间舒张压均有明显下降,差异有统计学意义（P〈0．05）。两组治疗后24h舒张压、白昼收缩压、白昼舒张压、夜间舒张压比较,差异无统计学意义（P〉0．05）。B组治疗后24h收缩压、夜间收缩压比A组改善明显,差异有统计学意义（P〈0．05）。结论早晨或夜间服用坎地沙坦均能有效降低非杓型高血压的血压水平及改善血压昼夜节律,但夜间服药组在控制夜间收缩压和纠正血压昼夜节律方面更有优势。     

Efficacy and safety of a once daily graded-release diltiazem formulation in essential hypertension

BACKGROUND: The efficacy and safety of a chronotherapeutic, graded-release diltiazem HCl extended-release (GRD) 120-, 240-, 360- and 540-mg dose administered once-daily at bedtime (10 PM) were evaluated in a 7-week randomized, double-blind comparison to placebo and to GRD 360 mg administered once-daily at 8 AM in 478 patients with moderate-to-severe essential hypertension. METHODS: We assessed the change from baseline to end point in trough diastolic blood pressure (DBP) at 6 PM to 10 PM and in mean DBP from 6 AM to 12 noon between GRD 360 mg PM and GRD 360 mg AM, measured by ambulatory BP monitoring (ABPM). RESULTS: Bedtime doses of GRD showed dose-related mean reductions in trough DBP that were significant for GRD doses of 240 mg and higher. Bedtime GRD 360 mg was associated with a significantly greater reduction in mean DBP between 6 AM and 12 noon compared to morning GRD 360 mg with a least squares mean for treatment difference of -3.3 mm Hg (P =.0004). Similar dose-related and significant reductions in systolic BP (SBP) and heart rate (HR) were obtained. Incidence of adverse events (AEs) for all GRD groups (44.5%) was less than that obtained for the placebo group (49.3%). The 540-mg group showed an incidence of AEs (43.5%) similar to that observed for the 240-mg group (42.6%). CONCLUSIONS: The GRD dose-dependently significantly reduces BP and HR over the 24-h interval after once-daily bedtime dosing. Further greater reductions were obtained between 6 AM and 12 noon, when circadian BP is highest, compared to morning administration of the same dose. The 540-mg GRD was safe, well tolerated, and offers further therapeutic option for patients with severe hypertension who required additional BP control.     

Administration time-dependent effects of valsartan on ambulatory blood pressure in hypertensive subjects

This study investigated the administration time-dependent antihypertensive efficacy of valsartan, an angiotensin II receptor blocker. We studied 90 subjects (30 men and 60 women), 49.0+/-14.3 (mean+/-SD) years of age with stage 1 to 2 essential hypertension; they were randomly assigned to receive valsartan (160 mg/d) as a monotherapy either on awakening or at bedtime. Blood pressure was measured by ambulatory monitoring every 20 minutes during the day and every 30 minutes at night for 48 consecutive hours before and after 3 months of treatment. Physical activity was simultaneously monitored every minute by wrist actigraphy to accurately calculate the diurnal and nocturnal means of blood pressure on a per-subject basis. The highly significant blood pressure reduction after 3 months of treatment with valsartan (P<0.001) was similar for both treatment times (17.0 and 11.3 mm Hg reduction in the 24-hour mean of systolic and diastolic blood pressure with morning administration and 14.6 and 11.4 mm Hg reduction with bedtime administration; P>0.174 for treatment time effect). Valsartan administration at bedtime as opposed to on wakening resulted in a highly significant average increase by 6% (P<0.001) in the diurnal-nocturnal ratio of blood pressure; this corresponded to a 73% relative reduction in the number of nondipper patients. The findings confirm that valsartan efficiently reduces blood pressure throughout the entire 24 hours, independent of treatment time. They also suggest that time of treatment can be chosen according to the dipper status of a patient to optimize the effect of antihypertensive therapy, an issue that deserves further investigation.     

Comparison of the efficacy of morning versus evening administration of telmisartan in essential hypertension

Valsartan administration at bedtime as opposed to on wakening improves the sleep time-relative blood pressure decline toward a more dipper pattern without loss in 24-hour efficacy. Yet to be determined is whether this administration time-dependent efficacy is a class-related feature, characteristic of all angiotensin receptor blockers or specific only to valsartan. Terminal half-life is a major difference between angiotensin receptor blockers, being largest ( approximately 24 hours) for telmisartan. This trial investigated the administration time-dependent antihypertensive efficacy of telmisartan. We studied 215 patients with hypertension (114 men and 101 women), 46.4+/-12.0 years of age, randomly assigned to receive telmisartan (80 mg/d) as a monotherapy either on awakening or at bedtime. Blood pressure was measured for 48 hours before and after 12 weeks of treatment. The significant blood pressure reduction after treatment was similar for both groups. Bedtime administration of telmisartan, however, was more efficient than morning dosing in reducing the nocturnal blood pressure mean. The sleep time-relative blood pressure decline was slightly reduced after telmisartan on awakening but significantly increased with bedtime dosing, thus reducing the prevalence of nondipping from baseline by 76%. Telmisartan administered at bedtime, as opposed to morning dosing, improved the sleep time-relative blood pressure decline toward a more dipper pattern without loss in 24-hour efficacy. Nocturnal BP regulation is significantly better achieved with bedtime dosing of telmisartan. Results from this prospective trial suggest that these beneficial features of bedtime dosing may be class related for angiotensin receptor blockers. These results should be taken into account when prescribing this class of antihypertensive medication for treatment of essential hypertension.     

The optimal timing of antihypertensive medication administration for morning hypertension in patients with cerebral infarction

Morning hypertension is an independent risk factor for cardiovascular diseases, particularly stroke. However, the optimal time at which to take antihypertensive medication to treat morning hypertension remains unclear. We prospectively enrolled elderly patients (over 65 years old) with morning hypertension who had suffered an ischemic stroke (or strokes). Additional treatments (one of six arms) were randomly administered for 10 weeks in the morning, in the evening or at bedtime (n=15 for each time point/medication). The patients measured their blood pressure and heart rate at home for 14 days prior to the intervention and for the final 14 days, and recorded the data in a blood pressure diary. The patients' urinary albumin/creatinine ratios were evaluated before and after the 10-week intervention. A total of 270 patients were enrolled in this study (mean age: 75.6±5.8 years; female/male ratio: 125/145). Their morning and evening systolic blood pressures were significantly decreased after following any of the study medication dosing schedules (P<0.001). However, the reductions in the differences between the morning and evening systolic blood pressures were significant only when the medication was taken in the evening or at bedtime (P<0.001 with repeated measures analysis of variance). Furthermore, the recovery rate from morning hypertension was also higher when the medication was taken in the evening (40.0%) or at bedtime (45.6%), rather than in the morning (22.2%; P=0.003 with the χ(2)-test). Antihypertensive medication taken in the evening or at bedtime is the most effective in treating morning hypertension when the patient adheres to the medication regimen.     

900例中老年高血压患者服药情况及动态血压监测的调查

目的调查目前高血压患者的服药情况及其对血压曲线的影响。方法随机选择门诊及住院的高血压患者,详细询问其病史和所服药物,并对其服用现有降压药物的情况进行24h动态血压监测。结果 (1)900例高血压患者中72例(占8%)未服任何降压药;单药治疗268例中,服用短效药物者171例(占63.8%),服用中长效药物者97例(占36.2%);联合治疗的560例中短效联合用药401例(占71.6%),中长效联合药159例(占28.4%)。(2)服用中长效单药治疗者其杓型、非杓型、超杓型及清晨高血压比例与服用短效药物者比较,差异均有统计学意义(P<0.05)。(3)联合治疗中长效药物其杓型、非杓型、超杓型、清晨高血压比例与短效联合药物比较,差异均有统计学意义(P<0.05)。结论 (1)对于高血压患者应该尽量服用长效药物,并且采取联合治疗,以有效、平稳控制血压,并调整患者血压的昼夜节律;(2)上级医院的专科医师应尽量多地组织基层治疗单位医师进行"中国高血压防治指南"的培训,使高血压防治更加规范化。     

肾血管性与原发性高血压患者24h动态血压的比较

目的 比较肾血管性高血压(RVH)与原发性高血压(EH)患者24 h动态血压的差别.方法 应用动态血压监测仪观察51例RVH患者的24 h动态血压,并与年龄、性别与之相匹配的51例EH患者的24 h动态血压进行比较.结果 RVH组24 h、白天及夜间动态收缩压、舒张压及脉压均值都比EH组有不同程度的升高(P<0.05),尤以夜间收缩压升高明显;血压负荷增加明显,24 h收缩压、舒张压负荷分别达到58.96%和35.98%,而EH组血压负荷均在20.00%左右,两组比较差异有统计学意义(P<0.05).EH组夜间血压下降率为10.36%,血压曲线呈勺型(60.8%的患者夜间血压下降率>10%);而RVH组夜间血压下降率为5.39%,血压曲线呈非勺型(仅有27.50%的患者夜间血压下降率>10%).结论 RVH患者动态血压均值、脉压和血压负荷明显增加,昼夜节律减弱.

Abstract：

Objective To compare 24 h ambulatory blood pressure changes between patients with renovascular hypertension and essential hypertension.Methods The 24 h ambulatory blood pressure of patients with age and gender matched renovascular hypertension (RVH, n=51) was compared with that of patients with essential hypertension (EH, n=51).Results The 24 h, daytime and nighttime systolic blood pressures(SBP),diastolic blood pressures(DBP) and pulse pressures (PP) in RVH were significantly higher than in EH (all P<0.05), especially the nocturnal SBP (P<0.05). The SBP and DBP loads in RVH were 58.96% and 35.98% respectively, while blood pressure loads were around 20.00% in EH (P<0.05). In patients with RVH, The nocturnal blood pressure fall was 5.39%, and only 27.50% patients were dippers, while the nocturnal blood pressure fall was 10.36% and 60.8% patients were dippers in EH.Conclusion RVH patients have higher dynamic BP, PP, BP loads and blunted diurnal rhythm compared to those with EH.