Cardiac arrhythmias and left ventricular hypertrophy in dipper and nondipper patients with essential hypertension

To evaluate the behavior of cardiac arrhythmias in dipper and nondipper hypertensive patients, 48-h ambulatory blood pressure monitoring, 24-h Holter electrocardiogram recording and echocardiographic studies were performed in 56 untreated outpatients with essential hypertension. These patients were divided into 2 groups according to the presence (dipper, n=33) or absence (nondipper, n=23) of reduction of both systolic and diastolic blood pressure during nighttime by an average of more than 10% of daytime blood pressure. Mean 48-h systolic and diastolic blood pressures did not differ between the 2 groups. Nondipper patients had a significantly larger left atrial dimension (31.9+/-3.8 vs 35.6+/-3.7 mm; p<0.01), left ventricular mass index (114+/-26 vs 136+/-36 g/m2; p<0.05), as well as a larger number of total supraventricular (16+/-19 vs 89+/-197 beats; p<0.05) and ventricular ectopic beats (7+/-14 vs 47+/-96 beats; p<0.05) during daytime as compared with dippers. In conclusion, nondipper hypertensive patients are likely to experience supraventricular and ventricular arrhythmias more frequently than dippers. A blunted nocturnal blood pressure fall may be involved in the appearance of cardiac arrhythmias in patients with essential hypertension.     

Left ventricular function, cardiac dysrhythmias, atrial activation, and volumes in nondipper hypertensive individuals with left ventricular hypertrophy

BACKGROUND: Arrhythmic patterns and left ventricular geometric adaptations to pressure overload were investigated in 76 patients with untreated borderline-to-moderate sustained essential hypertension studied by 2-dimensional and M-mode echocardiography, 12-lead, Holter, and signal-averaged electrocardiography, and ambulatory blood pressure monitoring. METHODS AND RESULTS: Sixty-two age- and sex-matched normal adults were chosen for data comparison. Hypertrophic hypertensive patients were subdivided into 2 subgroups: 44 patients with nocturnal blood pressure reduction (dippers) and 32 patients without it (nondippers). Common afterload and diastolic function indexes were found to be lower in combined nondipper and dipper groups, but only fractional shortening decreased in nondippers. The number of premature atrial and ventricular contractions per hour was high in dippers and nondippers, with no statistically significant differences between them; atrial and ventricular complex dysrhythmias were similar. Signal-averaged electrocardiography showed a prolonged P-wave duration in dipper and nondipper patients with high atrial volumes but no late ventricular potentials and no difference in quantitative P-wave analysis. Left atrial volumes, P-wave duration, and premature atrial contractions were found to be positively linked to left ventricular hypertrophy. In nondipper patients a linear correlation was observed between left atrial volume and P-wave duration, although supraventricular ectopic activity was connected to left atrial volume enlargement both in dipper and nondipper patients. CONCLUSIONS: These data suggest that the nondipper pattern is not linked to a worse arrhythmogenic substrate; only atrial volume increase may be related to significant supraventricular activity and prolonged atrial activation in nondipper patients, but late ventricular potentials are uncommon in hypertrophic hypertensive patients.     

Oxidative Stress Impairs Endothelial Function in Nondipper Hypertensive Patients

Aims: Essential hypertension, as well as other established cardiovascular risk factors, is associated with endothelial dysfunction. Hypertensive patients with a nondipper circadian pattern have a greater risk of cerebrovascular and cardiovascular complications in comparison with those with a dipper circadian pattern. In this study, we evaluated the association between nondipper pattern and endothelial function in patients with essential hypertension. Methods: We evaluated the forearm blood flow (FBF) response to intraarterial acetylcholine (ACh), an endothelium‐dependent vasodilator, and sodium nitroprusside (SNP), an endothelium‐independent vasodilator, infusions in 190 hypertensive patients stratified according to dipper and nondipper status. The FBF was measured by strain‐gauge plethysmography. Effects of oxidative stress on FBF were evaluated by intraarterial infusion of vitamin C. Ambulatory BP monitorings were obtained by a validated oscillometric device (SpaceLabs 90207 Monitor Inc., Issaquah, WA, USA). Results: Systolic and diastolic blood pressures were higher during daytime and lower during night‐time in dipper subjects than in nondippers. The peak percent increase in ACh‐stimulated FBF was higher in dippers than in nondippers (473% vs. 228%, P < 0.001). The FBF responses to SNP were similar in dipper and nondipper patients. The FBF response to ACh during coinfusion of vitamin C was higher in nondippers rather than in dipper hypertensives. Conclusions: Present data demonstrate that endothelium‐dependent vasodilation is impaired in patients who have nondipper hypertension. The effects of vitamin C on impaired ACh‐stimulated vasodilation support the hypothesis that oxidative stress contributes to endothelial dysfunction of nondipper hypertensive patients.     

Adrenergic, metabolic, and reflex abnormalities in reverse and extreme dipper hypertensives

Limited information is available on whether and to what extent the different patterns of the nocturnal blood pressure profile reported in hypertension are characterized by differences in sympathetic drive that may relate to, and account for, the different day-night blood pressure changes. In 34 untreated middle-aged essential hypertensive dippers, 17 extreme dippers, 18 nondippers, and 10 reverse dippers, we assessed muscle sympathetic nerve traffic, heart rate, and beat-to-beat arterial blood pressure at rest and during baroreceptor deactivation and stimulation. Measurements were also performed in 17 age-matched dipper normotensives. All patients displayed reproducible blood pressure patterns at 2 different monitoring sessions. The 4 hypertensive groups did not differ by gender or 24-hour or daytime blood pressure. Muscle sympathetic nerve traffic was significantly higher in nondipper, dipper, and extreme dipper hypertensives than in normotensive controls (58.6+/-1.8, 55.6+/-0.9, and 53.3+/-0.8 versus 43.5+/-1.4 bursts/100 heartbeats, respectively; P<0.01 for all), a further significant increase being detected in reverse dippers (76.8+/-3.1 bursts/100 heartbeats; P<0.05). Compared with normotensives, baroreflex-heart rate control was similarly impaired in all the 4 hypertensive states, whereas baroreflex-sympathetic control was preserved. The day-night blood pressure difference correlated inversely with sympathetic nerve traffic (r=-0.76; P<0.0001) and homeostasis model assessment index (r=-0.32; P<0.005). Thus, the reverse dipping state is characterized by a sympathetic activation greater for magnitude than that seen in the other conditions displaying abnormalities in nighttime blood pressure pattern. The present data suggest that in hypertension, sympathetic activation represents a mechanism potentially responsible for the day-night blood pressure difference.     

Relationship Between Exercise Heart Rate Recovery and Circadian Blood Pressure Pattern

J Clin Hypertens (Greenwich). 2010;12:407–413. ^©2010 Wiley Periodicals, Inc. The aim of the present cross-sectional study was to evaluate heart rate recovery (HRR) in normotensive and hypertensive individuals with either nondipper or dipper type circadian rhythm of blood pressure. Eighty-five patients were divided into 4 groups according to the presence of hypertension and pattern of circadian blood pressure as follows: (1) normotensive/dipper, n=20; (2) normotensive/nondipper, n=21; (3) hypertensive/dipper, n=22; and (4) hypertensive/nondipper, n=22. HRR indices were calculated by subtracting first, second, and third minute heart rates from the maximal heart rate obtained during stress testing and designated as HRR1, HRR2, and HRR3. Mean HRR1 values (29.7±4.0 vs 26.6±3.7, P=.016) were significantly higher in the normotensive/dipper group than the normotensive/nondipper group. Mean HRR1 values (28.6±4.0 vs 24.8±4.6 beats per minute, P=.007) were higher in the hypertensive/dipper group than the hypertensive/nondipper group. Spearman’s correlation analyses revealed a positive correlation between degree of nighttime dipping and HRR1 (r=.600, P=.001). The correlation coefficient between degree of nighttime dipping and HRR1 was higher in the hypertensive group than the normotensive group (r=.676, P=.001 and r=.575, P=.001, respectively). Blunting of the nocturnal fall in blood pressure associates with a delayed recovery of heart rate after graded maximal exercise in both normotensive and hypertensive groups.     

厄贝沙坦联合卡维地洛对高血压患者昼夜节律及心脏功能的影响

目的观察厄贝沙坦和卡维地洛联合治疗高血压的效果。方法300例高血压患者,根据动态血压结果,按照夜间血压下降率<10%为非杓型组,≥10%为杓型组。给与卡维地洛和厄贝沙坦联合治疗6个月。观察治疗前后动态血压和心脏结构及功能的变化。结果高血压存在着明显的昼夜节律。非杓型组与杓型组相比左心室质量、左心室质量指数及左心房内径、舒张功能障碍明显增加。治疗后,非杓型组昼夜节律恢复,心室质量、心脏舒张功能均有明显改善。结论卡维地洛和厄贝沙坦联合可以恢复高血压患者的昼夜节律,减轻心肌重塑,改善舒张功能。     

Clinical trial of arotinolol in the treatment of hypertension: dippers vs. non-dippers.

To compare the effects of an alpha, beta blocker, arotinolol, in the treatment of essential hypertension between patients with a dipper and those with a non-dipper profile by means of 24-h ambulatory blood pressure monitoring (ABPM), a multicenter single blind parallel trial was carried out in five clinical centers. After a one-week single blind placebo run-in period, the patients underwent ABPM if their clinic diastolic blood pressure (DBP) ranged from 90-109 mmHg and their clinic systolic blood pressure (SBP) was <180 mmHg. They were divided into two groups according to the absence (non-dipper group, 24 cases) or presence (dipper group, 23 cases) of nocturnal BP reduction > or =10% of daytime BP. ABPM was measured again at the end of the active treatment phase. All patients were given Arotinolol 10-20 mg twice daily for 4 weeks. Twenty four-hour systolic and diastolic average BPs (MSBP, MDBP), 24-h systolic and diastolic blood pressure load (LS BP, LDBP), daytime systolic and diastolic average BPs (dMSBP, dMDBP), daytime systolic and diastolic blood pressure load (dLSBP, dLDBP), nighttime systolic and diastolic average BPs (nMSBP, nMDBP) and nighttime systolic and diastolic blood pressure load (nLSBP, nLDBP) were calculated. Arotinolol was effective in 78.2% of dippers and 54.2% of non-dippers, but the difference in effectiveness between these groups was not statistically significant. After treatment, SBP and DBP-including 24-h, daytime and nighttime systolic and diastolic BPs- were significantly reduced in both groups. During the daytime period, the systolic and diastolic blood pressures were significantly reduced in both dippers and non-dippers, while nighttime systolic and diastolic blood pressures were significantly reduced only in the non-dipper group. No significant changes were found in the dipper group over this period. In conclusion, Arotinolol, which can be dosed twice daily, is an effective antihypertensive agent which effectively lowers blood pressure during the day while reducing nighttime blood pressure more in non-dippers than in dippers, without excessive lowering blood pressure in the latter.     

The relationship between eosinophil and nondipper hypertension

AimsNon-dipper hypertension is associated with increased cardiovascular morbidity and mortality. It is known that eosinophils play an important role in vasoconstriction and thrombosis. We aimed to compare the numbers of eosinophil counts of the patients nondipper versus dipper hypertension.Materials and methodThis study included 70 hypertensive patients. Hypertensive patients were divided into two groups: 35 dipper patients (15 male, mean age 50.94±11.13 years) and 35 non-dipper patients (10 male, mean age 56.11±11.05 years). Concurrent routine biochemical tests and eosinophil count on whole blood count were performed on these patients. These parameters were compared between groups.ResultsNo statistically significant difference was found between two groups in terms of basic characteristics. Baseline characteristics of the study groups were comparable. Nondipper patients had a higher eosinophil and MPV value than dipper patients (148.86±80 vs. 304.57±182 and 7.8±0.12 vs. 9.2±0.2 fl p<0.001, respectively).ConclusionEosinophil count and MPV value are higher in patients with nondipper hypertension when compared to the dippers.     

The influence of ambulatory blood pressure profile on left ventricular geometry

Besides causing a hypertrophy in the left ventricle, hypertension results in a change in the geometry of the left ventricle. The blood pressure, which does not decrease enough during the night, leads to structural changes in the left ventricle. In this study, the influence of 24-hour blood pressure profile on the left ventricular geometry was examined. Ambulatory blood pressure monitoring was applied to 60 patients with mild to moderate hypertension who had never been treated and standard echocardiographic evaluation was conducted thereafter. The patients were divided into two groups with respect to the ambulatory blood pressure profiles: the patients whose night blood pressure levels decreased by more than 10% compared to their daytime blood pressure levels (dipper) and those whose levels did not decrease that much (nondipper). The left ventricle mass index and the relative wall thickness of the patients were calculated. With respect to the left ventricle geometry, mass index and relative wall thickness of the patients were determined as: having normal geometry, concentric remodeling, eccentric hypertrophy, and concentric hypertrophy. Age, gender, systolic, and diastolic blood pressure were similar within the dipper and nondipper groups. Normal geometry, concentric remodeling, and concentric hypertrophy ratios were similar in both groups. Eccentric hypertrophy was higher in the nondipper group compared to the dipper group (42.9% vs 6.3%, P < 0.03). Patients with mild to moderate hypertension, whose blood pressure does not decrease enough, develop eccentric hypertrophy.     

Risk of atrial fibrillation in dipper and nondipper sustained hypertensive patients

OBJECTIVE: The risk of atrial fibrillation (AF) in sustained hypertensive patients with different circadian blood pressure (BP) patterns is unknown. We investigated the risk of new onset AF in dipper and nondipper sustained hypertensive patients. METHODS: The occurrence of AF was evaluated in 1141 patients aged > or = 40 years with sustained hypertension (clinic BP > or = 140 and/or 90 mmHg and daytime BP > or = 135 and/or 85 mmHg). Among these patients, 783 had night-time systolic BP fall > or = 10% (dippers) and 358 had night-time BP decline <10% (nondippers). RESULTS: During the follow-up (6.1+/-3.2, range 0.5-12.9 years), AF occurred in 43 patients. The AF rate per 100 patient-years in dippers and nondippers was 0.38 and 1.13, respectively. AF free survival was significantly different between the groups (P=0.0002). After adjustment for other covariates, including left atrial enlargement or left ventricular hypertrophy (these variables were analyzed in separate models because of a strong association between them) and 24-h BP, Cox regression analysis showed that the risk of AF was significantly higher in nondippers than in dippers [nondippers vs. dippers, relative risk (RR) 2.02, 95% confidence interval (CI) 1.08-3.79, P=0.028 in the model including left atrial enlargement, and RR 1.97, 95% CI: 1.05-3.69, P=0.035 in the model including left ventricular hypertrophy]. CONCLUSION: This study shows that nondipper sustained hypertensive patients have a two-fold greater risk of developing AF than dipper ones. This aspect could partly contribute to explain the higher cardiovascular risk previously observed in nondipper hypertensive patients.     

高血压患者血压节律与靶器官损害的相关性研究

目的 探讨高血压患者血压节律变化与心、脑、肾等靶器官损害的相关性。方法 应用无创性血压监测仪对84例高血压患者进行24小时动态血压监测,对比血压节律正常(勺型组)和异常(非勺型组)患者心、脑、肾靶器官损害程度。结果 非勺型组24小时平均收缩压和舒张压、白昼平均舒张压、夜间平均收缩压和舒张压、收缩压及舒张压负荷值较勺型组升高(P<0.01);左心室重量和重量指数显著增加(P<0.05,0.01),24小时平均动脉压与左心室重量指数呈显著相关性r=0.55,P<0.01;尿微量白蛋白阳性率明显增高(P<0.05);脑梗死发生率明显增加(P<0.05);组间在偶测平均收缩压和舒张压、白昼平均收缩压均无显著性差异(P>0.05)。结论 血压昼夜节律异常较节律正常的高血压患者有更显著的靶器官损害。     

Ambulatory blood pressure monitoring in secondary arterial hypertension due to adrenal diseases

The aim of this study was to evaluate ambulatory blood pressure monitoring in patients with essential hypertension and hypertension caused by adrenal pathology. Sixty-six patients with primary aldosteronism, 37 with pheochromocytomas, and 45 with adrenal incidentalomas were included. These patients were compared with 152 essential hypertensive patients and 64 normotensive subjects. Ambulatory blood pressure monitoring evaluated daytime and nighttime systolic and diastolic blood pressure and heart rate. The authors found that the "nondipper" phenomenon was present in 51.5% of patients with primary aldosteronism, 43.2% with pheochromocytomas, 42.2% with incidentalomas, 34.2% with hypertension, and 15% of subjects who were normotensive. In 58% of primary aldosteronism patients with idiopathic adrenal hyperplasia, there was an absence of the physiologic blood pressure nocturnal fall (nondipper), which was statistically significant (P<.001) compared with nondipper primary aldosteronism patients with adrenocortical adenoma (38%). In conclusion, the prevalence of the nondipping pattern was higher in patients with adrenal hypertension compared with patients with essential hypertension, suggesting an independent cardiovascular risk factor.     

Reproducibility study of nocturnal blood pressure dipping in patients with high cardiovascular risk

It has been shown that in most people there is a physiological reduction in blood pressure during nighttime sleep, it falling by approximately 10% compared to daytime values (dippers). On the other hand, in some people, there is no nighttime reduction (non‐dippers). Various studies have found an association between being a non‐dipper and a higher risk of cardiovascular disease, but few have assessed whether the nocturnal pattern is maintained over time. From the database of the TAHPS study, data were available on 225 patients, each of whom underwent 24‐hour ambulatory blood pressure monitoring (ABPM) on four occasions over a period of 5 months. We studied the reproducibility of the nocturnal BP dipping pattern with mixed linear analysis and also calculated the concordance in the classification of patients as dippers or non‐dippers. The intraclass correlation coefficients between the different ABPM recordings were 0.482 and 0.467 for systolic and diastolic blood pressure, respectively. Two‐thirds (67%) and 70% of the patients classified, respectively, as dippers or non‐dippers based on systolic and diastolic blood pressure readings in the first ABPM recording were found to have the same classification based on the subsequent recordings. We conclude that the reproducibility of nocturnal dipping patterns and concordance of dipper vs non‐dipper status in individual patients is modest and therefore that we should be cautious about recommending treatments or interventions based on these patterns.     

Serum Uric Acid,Inflammation, and Nondipping Circadian Pattern in Essential Hypertension

Uric acid (UA) is independently associated with the emergence of hypertension. Nocturnal nondipping pattern of hypertension is associated with a greater risk of cardiovascular, renal, and cerebrovascular complications than dippers. The aim of the present study was to evaluate the relationship between the circadian blood pressure rhythm and UA level in patients with newly diagnosed essential hypertension. The study included 112 essential hypertensive patients and 50 healthy controls. The hypertensive patients were divided into two groups according to the results of 24‐hour ambulatory blood pressure monitoring, including 60 dippers (35 men, 25 women; mean age, 52.6±15.8 years) and 52 nondippers (29 men, 23 women; mean age, 55.9±13.2 years). Nondippers had significantly higher serum UA levels than the dippers and controls (5.8±0.8, 5.1±0.9 and 4.2±0.9 mg/dL, respectively; P<.001). Serum high‐sensitivity C‐reactive protein levels were also significantly higher in the nondipper group than the other groups (P<.001) and significantly correlated with serum UA (r=0.358, P<.001). Multivariate logistic regression analysis revealed an independent positive association between serum UA levels and nondipper pattern (odds ratio, 2.28; 95% confidence interval, 1.33–3.94; P=.003). Serum UA is strongly and independently associated with the nondipper circadian pattern in essential hypertension.     

Noctural dipping status and left ventricular hypertrophy: A cardiac magnetic resonance imaging study

We investigate the impact of dipper status on cardiac structure with cardiovascular magnetic resonance (CMR). Ambulatory blood pressure monitoring and 1.5T CMR were performed in 99 tertiary hypertension clinic patients. Subgroup analysis by extreme dipper (n = 9), dipper (n = 39), non‐dipper (n = 35) and reverse dipper (n = 16) status was performed, matched in age, gender and BMI. Left ventricular (LV) mass was significantly higher for extreme dippers than dippers after correction for covariates (100 ± 6 g/m² vs 79 ± 3 g/m², P = .004). Amongst extreme dippers and dippers (n = 48), indexed LV mass correlated positively with the extent of nocturnal blood pressure dipping (R = .403, P = .005). On post‐hoc ANCOVA, the percentage of nocturnal dip had significant effect on indexed LV mass (P = .008), but overall SBP did not (P = .348). In the tertiary setting, we found a larger nocturnal BP drop was associated with more LV hypertrophy. If confirmed in larger studies, this may have implications on nocturnal dosing of anti‐hypertensive medications.     

Is HOMA index a predictor of nocturnal nondipping in hypertensives with newly diagnosed type 2 diabetes mellitus?

OBJECTIVE: Insulin resistance is involved in glucose intolerance, type 2 diabetes mellitus and hypertension. We aimed to analyze relationship between insulin resistance and nocturnal nondipping. METHODS: Patients underwent physical and biochemical evaluation, clinic and ambulatory blood pressure measurements. The homeostasis model assessment (HOMA) index was calculated. RESULTS: Ninety-six essential hypertensive patients, of whom 42 were dippers, with newly diagnosed type 2 diabetes mellitus were included. Nighttime average heart rate and mean arterial pressure of nondippers were higher than dippers (P<0.0001 and 0.001). Nondippers had higher fasting plasma glucose, serum insulin levels and HOMA indices than dipper patients (P=0.006, <0.0001 and <0.0001). Ten dippers and 36 nondippers were insulin resistant (P<0.0001). Clinic (r=+0.22, P=0.031), daytime average (r=+0.27, P=0.007), nighttime average (r=+0.33, P=0.001), 24-h average systolic (r=+0.25, P=0.015) and nighttime average diastolic blood pressures (r=+0.31, P=0.002) were positively correlated with homeostasis model assessment index. Nighttime mean arterial pressure and heart rates (daytime, nighttime, 24-h average) showed positive correlation with homeostasis model assessment index. In multivariate analysis, high homeostasis model assessment index was associated with increased nondipping risk (odds ratio: 1.85, confidence interval: 1.24-2.76, P=0.003). After adjustment of several factors, average nighttime systolic (P<0.0001), diastolic (P<0.0001) and 24-h diastolic blood pressure (P=0.029) and heart rate (P=0.001) measurements of insulin resistant patients were higher than nonresistant patients. CONCLUSIONS: Insulin resistance is related with diurnal blood pressure variation. The HOMA index may be a predictor of nocturnal nondipping in patients with essential hypertension and newly diagnosed type 2 diabetes mellitus.     

Circadian Variation of Blood Pressure Is Impaired in Normotensive Pregnant Women with Gestational Diabetes Mellitus

Data about circadian blood pressure (BP) in normotensive patients with gestational diabetes mellitus (GDM) are lacking. Thus, we sought to compare dipper and nondipper circadian variation of BP profile between normotensive women complicated with GDM and normal pregnant women. Forty-two women with GDM and 33 normal uncomplicated pregnant women who met the entry criteria for the study were enrolled in the study. Twenty-four-hour noninvasive ambulatory blood pressure monitoring and echocardiography to measure the left ventricle mass index and diastolic parameters were performed. Nocturnal blood pressure dipping was calculated as follows: (awake BP – sleep BP) × 100/awake BP. Patients with a nocturnal reduction in average daytime systolic BP and diastolic BP of less than 10% were classified as nondippers. Left ventricle mass index was higher in normotensive pregnant women with GDM group than in normal pregnant subjects (101.98 ± 24 g/m² vs. 90.67 ± 15 g/m², P < .018). Significant nocturnal systolic and diastolic nondippings were observed in GDM groups compared with normal subjects. From diastolic variables, the mitral E velocity and isovolumetric relaxation time were compatible with diastolic dysfunction relaxation abnormalities (P = .003 and P = .015, respectively) in nondipper group. From all confounding factors, only E velocity (P = .002) and diagnosis of GDM (P < .001) were predictive of nondipper circadian variation. This study shows that (i) circadian BP is impaired in normotensive pregnant subjects with GDM, (ii) the left ventricle mass index is higher in pregnant subjects with GDM than in normal pregnant subjects who despite a 24-hour BP are within normal limits, and (iii) in nocturnal nondipper group, the tendency to having diastolic relaxation abnormalities is noted.     

组织多普勒成像评价血压昼夜节律变异对左心室舒张功能的影响

目的探讨血压昼夜节律变异对左心室舒张功能的影响。方法31例非杓型高血压患者(非杓型组)和31例年龄、性别相匹配的杓型高血压患者(杓型组)入选。两组患者均行24 h动态血压监测和组织多普勒成像(DTI)检查。结果两组日间平均收缩压和平均舒张压无显著性差异,非杓型组的夜间平均收缩压和平均舒张压均显著高于杓型组[(145.1±34.5)mm Hg(1 mm Hg=0.133 kPa)vs(127.9±18.1)mm Hg,(94.2±38.1)mm Hgvs(78.5±18.2)mm Hg,P<0.05]。心脏超声检查显示两组在心腔内径、室壁厚度和左心室射血分数等参数无显著性差异,DTI结果显示非杓型组的平均组织舒张早期速度(MEa)、MEa/平均组织舒张晚期速度(MAa)显著低于杓型组[(5.9±2.1)cm/svs(7.8±3.1)cm/s,(0.68±0.56)cm/svs(0.95±0.39)cm/s,P<0.05和P<0.01)];非杓型组的MAa较杓型组明显升高[(9.5±2.8)cm/svs(8.6±1.7)cm/s,P<0.01]。结论血压昼夜节律变异可加重左心室舒张功能受损。对于存在血压昼夜节律变异的高血压患者应尽早诊断,积极治疗和加强随访。     

Nocturnal reduction of blood pressure and the antihypertensive response to a diuretic or angiotensin converting enzyme inhibitor in obese hypertensive patients

During a 12-week, multicenter study to evaluate the efficacy and safety of lisinopril and hydrochlorothiazide (HCTZ) for the treatment of obesity-related hypertension, ambulatory blood pressure (ABP) monitoring was performed both at baseline and at study completion in 124 patients. Patients were randomized to three groups: placebo, lisinopril (10, 20, or 40 mg/day), or HCTZ (12.5, 25, or 50 mg/day). All groups were matched with regard to sex, race, age, body mass index, and waist/hip ratio. The primary analysis of ABP data revealed that both lisinopril and HCTZ effectively lowered mean 24-h systolic (SBP) and diastolic (DBP) blood pressure compared with placebo, (mean change from baseline SBP/DBP: −12.0/−8.2, −10.6/−5.5, and −0.3/−0.5 mm Hg, respectively); however, lisinopril lowered DBP better than HCTZ (P < .05). Secondary analyses of groups revealed that men responded better to lisinopril than HCTZ (−11.9/−7.3 v −6.6/−3.5 mm Hg, respectively), whereas women responded well to both drugs. White patients responded better to lisinopril than HCTZ, whereas black patients showed a significant response to HCTZ only. Response to treatment was also influenced by patient classification of 24-h blood pressure profiles, ie, “dipper” or “nondipper.” Overall, the majority of obese hypertensives were nondippers. Nondippers (n = 82) responded well to both drugs (−10.4/−6.9 v −12.5/−5.7 mm Hg, P < .05 v placebo), whereas dippers (n = 42) responded to lisinopril (−11.7/−9.4 mm Hg, P < .05 v placebo and HCTZ), but not HCTZ (−5.6/−4.1 mm Hg, P = NS v placebo). Results of 24-h ABP data show that both lisinopril and HCTZ are effective therapies for obesity-related hypertension and that response to treatment is influenced by sex, race, and dipper/nondipper status.     

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.