Abnormal blood pressure circadian rhythm: a target organ damage?

Consumption of plant sterols-enriched soy milk with a healthy dietary pattern diet lowers blood pressure in adults with metabolic syndrome: A randomized controlled trial

BACKGROUND & AIMS

Plant sterols (PS) have been shown to lower blood lipid-lipoproteins concentrations and may serve as a potential functional ingredient for cardiovascular disease (CVD) risk management. However, there are limited studies examining this effect in individuals with metabolic syndrome (MetS). The aim of this study was to evaluate the effects of PS-enriched food consumption as part of a healthy dietary pattern (HDP) on blood pressure and endothelial function in Singaporean adults with MetS.

METHODS AND RESULTS

This was a 12-week, crossover, randomized controlled trial with a 4-week washout period. Thirteen subjects were instructed to consume an HDP diet either with normal soy milk (control group) or with PS (2 g/day)-enriched soy milk (PS group) for 4 weeks. Blood lipid-lipoproteins and glucose concentrations, blood pressure, and endothelial function-related indicators (flow-mediated dilation, total plasma nitrate/nitrite and endothelin-1, circulating endothelial progenitor cells) were assessed before and after the intervention. Systolic blood pressure [mean change, PS group: -4.0 ± 3.7 mmHg; control group: 5.9 ± 2.5 mmHg (PInteraction = 0.01)] and long-term CVD risk [mean change, PS group: -0.2 ± 1.0 %; control group: 2.7 ± 1.3 % (PInteraction = 0.03)] decreased following PS consumption. No changes were observed in the other endothelial function-related outcomes.

CONCLUSIONS

Consumption of PS-enriched food with an HDP diet may lower blood pressure and long-term CVD risk in adults with MetS.

CLINICAL TRIAL REGISTRATION

NCT03723330, https://clinicaltrials.gov/.

Inflammation-based markers, especially the uric acid/albumin ratio, are associated with non-dipper pattern in newly diagnosed treatment-naive hypertensive patients

OBJECTIVE

Physiologically, at night, blood pressure (BP) is expected to decrease by at least 10% in hypertensive individuals. The absence of this decrease, called non-dipper hypertension, is associated with increased end-organ damage and cardiovascular mortality and morbidity in hypertensive individuals. It is known that increased inflammatory process plays an important role in the etiopathogenesis of non-dipper hypertension pattern. In recent years, it has been shown that inflammation-based markers (IBMs) obtained by combining various inflammation-related hematological and biochemical parameters in a single fraction have stronger predictive value than single inflammatory parameters. However, until now, there has not been a study investigating the relationship of these markers with dipper/non-dipper status in newly diagnosed hypertensive patients.

METHODS

Based on ambulatory BP monitoring, 217 dipper and 301 non-dipper naive hypertensive subjects were included in this study. All subjects' IBM values were compared between dipper and non-dipper hypertensive individuals.

RESULTS

IBMs [C-reactive protein/albumin ratio (CAR), monocyte/high-density lipoprotein cholesterol ratio (MHR), neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio, systemic immune-inflammation index (SII), uric acid/albumin ratio (UAR)] were significantly higher in the non-dipper group. CAR, MHR, NLR, SII, and UAR were determined as independent predictors for non-dipper pattern ( P  < 0.05, for all). Also, UAR's diagnostic performance for non-dipper pattern was found to be superior to other IBMs (area under the curve: 0.783, 95% confidence interval: 0.743-0.822; P  < 0.001).

CONCLUSION

These findings suggest an association between elevated IBMs, particularly UAR, and the non-dipper hypertension pattern observed in our study.

Heart rate deceleration and acceleration capacities associated with circadian rhythm of blood pressure in essential hypertension

BACKGROUND

This study aimed to investigate the potential association between the circadian rhythm of blood pressure and deceleration capacity (DC)/acceleration capacity (AC) in patients with essential hypertension.

METHODS

This study included 318 patients with essential hypertension, whether or not they were being treated with anti-hypertensive drugs, who underwent 24-hour ambulatory blood pressure monitoring (ABPM). Patients were categorized into three groups based on the percentage of nocturnal systolic blood pressure (SBP) dipping: the dipper, non-dipper and reverse dipper groups. Baseline demographic characteristics, ambulatory blood pressure monitoring parameters, Holter recordings (including DC and AC), and echocardiographic parameters were collected.

RESULTS

In this study, the lowest DC values were observed in the reverse dipper group, followed by the non-dipper and dipper groups (6.46 ± 2.06 vs. 6.65 ± 1.95 vs. 8.07 ± 1.79 ms, P < .001). Additionally, the AC gradually decreased (-6.32 ± 2.02 vs. -6.55 ± 1.95 vs. -7.80 ± 1.73 ms, P < .001). There was a significant association between DC (r = .307, P < .001), AC (r=-.303, P < .001) and nocturnal SBP decline. Furthermore, DC (β = 0.785, P = .001) was positively associated with nocturnal SBP decline, whereas AC was negatively associated with nocturnal SBP (β = -0.753, P = .002). By multivariate logistic regression analysis, deceleration capacity [OR (95% CI): 0.705 (0.594-0.836), p < .001], and acceleration capacity [OR (95% CI): 1.357 (1.141-1.614), p = .001] were identified as independent risk factors for blood pressure nondipper status. The analysis of ROC curves revealed that the area under the curve for DC/AC in predicting the circadian rhythm of blood pressure was 0.711/0.697, with a sensitivity of 73.4%/65.1% and specificity of 66.7%/71.2%.

CONCLUSIONS

Abnormal DC and AC density were correlated with a blunted decline in nighttime SBP, suggesting a potential association between the circadian rhythm of blood pressure in essential hypertension patients and autonomic nervous dysfunction.

Cardiovascular rhythmicity in overweight and obese children

INTRODUCTION

Obesity is thought to play a role in the disruption of cardiac rhythmicity in obese children, but this is mostly an unexplored field of investigation. We aimed to evaluate the impact of overweight and obesity on circadian and ultradian cardiovascular rhythmicity of prepubertal children, in comparison with normal weight counterparts.

METHODS

We performed a cross sectional study of 316 children, followed in the birth cohort Generation XXI (Portugal). Anthropometrics and 24-hour ambulatory blood pressure were measured and profiles were examined with Fourier analysis for circadian and ultradian blood pressure (BP) and heart rate (HR) rhythms.

RESULTS

Overweight/obese children presented more frequently a non-dipping BP pattern than normal weight counterparts (31.5% vs. 21.6%, p = 0.047). The prevalence of 24-hour mean arterial pressure (MAP) and 8-hour HR rhythmicity was significantly lower in obese children (79.3% vs. 88.0%, p = 0.038 and 33.3% vs. 45.2%, p = 0.031, respectively). The prevalence of the remaining MAP and HR rhythmicity was similar in both groups. No differences were found in the median values of amplitudes and acrophases of MAP and HR rhythms.

DISCUSSION

The alterations found in rhythmicity suggest that circadian and ultradian rhythmicity analysis might be sensitive in detecting early cardiovascular dysregulations, but future studies are needed to reinforce our findings and to better understand their long-term implications.

Brain Dopamine-Clock Interactions Regulate Cardiometabolic Physiology: Mechanisms of the Observed Cardioprotective Effects of Circadian-Timed Bromocriptine-QR Therapy in Type 2 Diabetes Subjects

Despite enormous global efforts within clinical research and medical practice to reduce cardiovascular disease(s) (CVD), it still remains the leading cause of death worldwide. While genetic factors clearly contribute to CVD etiology, the preponderance of epidemiological data indicate that a major common denominator among diverse ethnic populations from around the world contributing to CVD is the composite of Western lifestyle cofactors, particularly Western diets (high saturated fat/simple sugar [particularly high fructose and sucrose and to a lesser extent glucose] diets), psychosocial stress, depression, and altered sleep/wake architecture. Such Western lifestyle cofactors are potent drivers for the increased risk of metabolic syndrome and its attendant downstream CVD. The central nervous system (CNS) evolved to respond to and anticipate changes in the external (and internal) environment to adapt survival mechanisms to perceived stresses (challenges to normal biological function), including the aforementioned Western lifestyle cofactors. Within the CNS of vertebrates in the wild, the biological clock circuitry surveils the environment and has evolved mechanisms for the induction of the obese, insulin-resistant state as a survival mechanism against an anticipated ensuing season of low/no food availability. The peripheral tissues utilize fat as an energy source under muscle insulin resistance, while increased hepatic insulin resistance more readily supplies glucose to the brain. This neural clock function also orchestrates the reversal of the obese, insulin-resistant condition when the low food availability season ends. The circadian neural network that produces these seasonal shifts in metabolism is also responsive to Western lifestyle stressors that drive the CNS clock into survival mode. A major component of this natural or Western lifestyle stressor-induced CNS clock neurophysiological shift potentiating the obese, insulin-resistant state is a diminution of the circadian peak of dopaminergic input activity to the pacemaker clock center, suprachiasmatic nucleus. Pharmacologically preventing this loss of circadian peak dopaminergic activity both prevents and reverses existing metabolic syndrome in a wide variety of animal models of the disorder, including high fat-fed animals. Clinically, across a variety of different study designs, circadian-timed bromocriptine-QR (quick release) (a unique formulation of micronized bromocriptine-a dopamine D2 receptor agonist) therapy of type 2 diabetes subjects improved hyperglycemia, hyperlipidemia, hypertension, immune sterile inflammation, and/or adverse cardiovascular event rate. The present review details the seminal circadian science investigations delineating important roles for CNS circadian peak dopaminergic activity in the regulation of peripheral fuel metabolism and cardiovascular biology and also summarizes the clinical study findings of bromocriptine-QR therapy on cardiometabolic outcomes in type 2 diabetes subjects.

Ambulatory blood pressure profile and stroke recurrence

OBJECTIVES

To establish a new ambulatory blood pressure (ABP) parameter (24-hour ABP profile) and evaluated its performance on stroke outcome in ischaemic stroke (IS) or transient ischaemic attack (TIA) patients.

METHODS

The prospective cohort consisted of 1996 IS/TIA patients enrolled for ABP monitoring and a 3-month follow-up for stroke recurrence as outcome. Profile groups of systolic blood pressure (SBP) were identified via an advanced functional clustering method, and the associations of the profile groups and conventional ABP parameters with stroke recurrence were examined in a Cox proportional hazards model.

RESULTS

Three discrete profile groups (n=604, 781 and 611 in profiles 1, 2 and 3, respectively) in 24-hour ambulatory SBP were identified. Profile 1 resembled most to the normal diurnal blood pressure pattern; profile 2 also dropped at night, but climbed earlier and with higher morning surge; while profile 3 had sustained higher nocturnal SBP without significant nocturnal SBP decline. The incidence of stroke recurrence was 2.9%, 3.9% and 5.5% in profiles 1, 2 and 3, respectively. After adjustment for covariates, profile 3 was significantly associated with higher risk of stroke recurrence with profile 1 as reference (HR 1.76, 95% CI: 1.00 to 3.09), while no significant difference was observed between profiles 2 and 1 (HR 1.22, 95% CI: 0.66 to 2.25). None of conventional ABP parameters showed significant associations with the outcome.

CONCLUSIONS

Ambulatory 24-hour SBP profile is associated with short-term stroke recurrence. Profiles of ABP may help improve identification of stroke recurrence by capturing the additive effects of individual ABP parameters.

Whole blood viscosity predicts nondipping circadian pattern in essential hypertension

Aim: We aimed to investigate the association between whole blood viscosity (WBV) and nondipping pattern in patients with essential hypertension. Materials & methods: A total of consecutive 530 patients who had been evaluated by ambulatory blood pressure monitoring were included. WBV was estimated by using hematocrit and plasma total protein levels for both WBV in low shear rate (0.5 s-1) and WBV in high shear rate (208 s-1) according to the de Simone's formula. Results: In the multivariate analysis, low shear rate and high shear rate of WBV were associated independently with nondipping pattern in patients with essential hypertension. Conclusion: As a simple, inexpensive and noninvasive tool, WBV seems to be a significant predictor of nondipping hypertension.

Impact of Circadian Blood Pressure Pattern on Silent Cerebral Small Vessel Disease: A Systematic Review and Meta-Analysis

Background

Abnormal circadian blood pressure (BP) variations during sleep, specifically the non‐dipping (<10% fall in nocturnal BP) and reverse‐dipping patterns (rise in nocturnal BP), have been associated with an increased risk of cardiovascular events and target organ damage. However, the relationship between abnormal sleep BP variations and cerebral small vessel disease markers is poorly established. This study aims to assess the association between non‐dipping and reverse‐dipping BP patterns with markers of silent cerebral small vessel disease.

Methods and Results

MEDLINE, Embase, and Cochrane Databases were searched from inception through November 2019. Studies that reported the odds ratios (ORs) for cerebral small vessel disease markers in patients with non‐dipping or reverse‐dipping BP patterns were included. Effect estimates from the individual studies were extracted and combined using the random‐effect, generic inverse variance method of DerSimonian and Laird. Twelve observational studies composed of 3497 patients were included in this analysis. The reverse‐dipping compared with normal dipping BP pattern was associated with a higher prevalence of white matter hyperintensity with a pooled adjusted OR of 2.00 (95% CI, 1.13–2.37; I²=36%). Non‐dipping BP pattern compared with normal dipping BP pattern was associated with higher prevalence of white matter hyperintensity and asymptomatic lacunar infarction, with pooled ORs of 1.38 (95% CI, 0.95–2.02; I²=52%) and 2.33 (95% CI, 1.30–4.18; I²=73%), respectively. Limiting to only studies with confounder‐adjusted analysis resulted in a pooled OR of 1.38 (95% CI, 0.95–2.02; I²=52%) for white matter hyperintensity and 1.44 (95% CI, 0.97–2.13; I²=0%) for asymptomatic lacunar infarction.

Conclusions

The non‐dipping and reverse‐dipping BP patterns are associated with neuroimaging cerebral small vessel disease markers.

Assessment of pupillary autonomic functions by dynamic pupillometry in different circadian arterial blood pressure patterns

OBJECTIVE

The aim of the present cross-sectional study was to evaluate the autonomic nervous system by dynamic pupillometry (DP) in normotensive and hypertensive individuals with either a non-dipper-type or a dipper-type circadian rhythm of blood pressure (BP).

PATIENTS AND METHODS

A total of 80 patients were allocated into four groups: normotensive/dipper (n=23), normotensive/nondipper (n=19), hypertensive/dipper (n=18), and hypertensive/nondipper (n=20). Pupil diameters (R0, R1, R2, and R%): latency (Lc), amplitude (Ac), velocity (Vc), and duration (Tc) of pupil contraction: latency (Ld), velocity (Vd), and duration (Td) of pupil dilatation were measured by DP. Among the DP parameters, Vc and Ac were known parasympathetic indices and R% was the major sympathetic index.

RESULTS

Vc and Ac were higher in the dipper normotensives with respect to nondipper normotensives (Vc=5.19±0.85 vs. 4.58±0.71, P=0.017; Ac=1.66±0.27 vs. 1.49±0.28, P=0.048). Vc and Ac were higher in dipper hypertensives with respect to the nondipper subgroup of hypertensive cases (Vc=4.44±0.81 vs. 3.94±0.45, P=0.024; Ac=1.47±0.26 vs. 1.27±0.11, P=0.004). R% was higher in the nondipper subgroup of hypertensives than the dipper subgroup of hypertensive cases (36.7±4.8 vs. 33.5±3.8, P=0.033). Correlation analyses showed moderate positive correlations of night-time decline in BP with Vc (r=0.460, P=0.001) and Ac (r=0.420, P=0.001). There was also a negative correlation between night-time decline in BP and R% (r=-0.259, P=0.001).

CONCLUSION

Nondipping in BP is associated with lower parasympathetic activity both in normotensive and in hypertensives cases. Furthermore, in the nondipper subgroup of hypertensive cases, there is higher sympathetic activity than the dipper subgroup.

Cultural factors and the circadian rhythm of ST elevation myocardial infarction in patients in a Mediterranean island

INTRODUCTION

The circadian rhythm of onset of myocardial infarction shows an increased risk during the morning hours. However, it is not clear whether habits, culture and sunshine hours differentiate circadian rhythm. The aim of this study was to investigate the influence of cultural factors on the circadian rhythm of acute myocardial infarction with ST segment elevation in a Mediterranean island.

METHOD

The study was a retrospective correlational survey. It included 123 patients with ST elevation myocardial infarction (mean age 60.7±12.6; 82% men). The 24 h of a day were divided into four six-hour periods of time for study purposes (00:01-06:00; 06:01-12:00; 12:01-18:00; and 18:01-24:00) and the chi-square test was used for the analysis.

RESULTS

A morning peak of symptoms onset of ST-elevation myocardial infarction was detected during the period 06:01-12:00 (p=0.044). In patients who were smokers, a bimodal pattern involving a morning (06:01-12:00) and an afternoon-to-night peak (18:01-24:00) (p=0.005) was detected. For patients with a history of hypertension, a morning peak of their symptoms was also detected (p=0.028). Different circadian variations were found between patients over the age of 60 years old and patients under the age of 60 years old (p=0.025).

CONCLUSIONS

Patients with ST elevation myocardial infarction seem to follow a circadian rhythm with a peak of onset of symptoms in the morning. In the smokers' subgroup, a different circadian pattern was found. The habit of smoking is likely to affect the circadian rhythm of the onset of ST elevation myocardial infarction in the Mediterranean area and culture.

Relation of blood pressure variability to left ventricular function and arterial stiffness in hypertensive patients

INTRODUCTION

Variability of blood pressure (BP) has been reported to be related to worse cardiovascular outcomes. We examined the impact of daytime systolic BP variability on left ventricular (LV) function and arterial stiffness in hypertensive patients.

METHODS

Ambulatory BP monitoring (ABPM) and echocardiography were performed in 116 hypertensive patients. We assessed BP variability as standard deviations of daytime systolic BP on 24-hour ABPM. Conventional echocardiographic parameters, area strain and three-dimensional diastolic index (3D-DI) using 3D speckle tracking were measured. Arterial stiffness was evaluated by acquiring pulse wave velocity (PWV) and augmentation index.

RESULTS

Patients with higher BP variability showed significantly increased left ventricular mass index (LVMI) and late mitral inflow velocity, as well as decreased E/A (early mitral inflow velocity/late mitral inflow velocity) ratio, area strain and 3D-DI than those with lower BP variability (LVMI: p = 0.02; A velocity: p < 0.001; E/A ratio: p < 0.001; area strain: p = 0.02; 3D-DI: p = 0.04). In addition, increased BP variability was associated with higher PWV and augmentation index (p < 0.001). Even among patients whose BP was well controlled, BP variability was related to LV mass, diastolic dysfunction and arterial stiffness.

CONCLUSION

Increased BP variability was associated with LV mass and dysfunction, as well as arterial stiffness, suggesting that BP variability may be an important determinant of target organ damage in hypertensive patients.

Relationship between arterial stiffness and circadian pattern of blood pressure

Arterial stiffness is a risk factor for cardiovascular morbidity and mortality. The relationship between the arterial stiffness and the circadian pattern of blood pressure (BP) has been controversial. The objective of the present study was to investigate the relationship between arterial stiffness by pulse wave analysis (PWA) and variables of 24-hour ambulatory BP monitoring (ABPM) in patients with high normal BP or hypertension (HTN).Five hundred forty-eight patients (304 males, 48 ± 12-year-old) with high normal BP or HTN were enrolled. BP was measured at the outpatient clinic and 24-hour ABPM was performed. Using radial applanation tonometry, PWA was performed for evaluation of systemic arterial stiffness. Patients were classified into four groups according to the dipping patterns: a nocturnal dipping group, an isolated systolic non-dipping group, an isolated diastolic non-dipping group and a both systolic and diastolic non-dipping group. For adjustment of age, population was divided to 2 groups: old group ≥55 year-old (n = 158, 75 males), young group <55 year-old (n = 390, 229 males).According to the dipping patterns, augmentation pressure (AP), augmentation index (AI) and heart rate (75 bpm) adjusted AI (AI@HR75) showed statistically significant difference (P = .011, .009, and .018, respectively). Multivariate analysis showed that isolated diastolic non-dipping was correlated with arterial stiffness expressed as AI and AI@HR 75, only in young group (β-coefficient = 12.6, P = .04 and β-coefficient = 7.503, P = .028, respectively).Arterial stiffness might be closely related with the pattern of non-dipping in young patients with HTN and high normal BP.

Association between Growth Differentiation Factor 15 and Non-Dipping Circadian Pattern in Patients with Newly Diagnosed Essential Hypertension

OBJECTIVE

Non-dipper hypertension (HT) confers greater risk compared with dipper HT. Growth differentiation factor 15 (GDF-15) recently emerged as a novel and independent marker of cardiovascular disease, both in diagnostic and prognostic scopes. Our aim was to evaluate the relationship of circadian blood pressure (BP) pattern with serum GDF-15 level in newly diagnosed HT patients without left ventricular hypertrophy.

SUBJECTS AND METHODS

Newly diagnosed non-dipper (n = 66) and dipper (n = 60) HT patients were selected according to 24-h ambulatory BP monitoring (ABPM). The controls comprised healthy normotensive subjects (n = 31). Data was collected through physical examination, laboratory analysis, ABPM, and echocardiography. GDF-15 was measured using ELISA.

RESULTS

Greater GDF-15 level was found in the non-dippers compared with the dippers and the controls (557.53 ± 91.7, 513.79 ± 62.86, and 494.44 ± 79.30 ng/L, respectively, p < 0.001). In bivariate linear correlation analysis, GDF-15 correlated positively with glomerular filtration rate (r = 0.180, p =0.030), total cholesterol (r = 0.170, p = 0.038), septal E/E' ratio (r = 0.344, p = 0.001), lateral E/E' ratio (r = 0.366, p < 0.001), nighttime systolic BP (r = 0.166, p = 0.046), and nighttime diastolic BP (r = 0.188, p = 0.024); however, it correlated negatively with septal and lateral E' velocities (r = 0.268, p = 0.005 and r = 0.236, p = 0.013, respectively). Furthermore, GDF-15 level and nighttime diastolic BP remained independently associated with non-dipper HT. In ROC analysis, optimal cutoff value for GDF-15 was 524.6 ng/L with 56.7% sensitivity and 72.4% specificity (AUC: 0.676, 95% CI: 0.580-0.772, p < 0.05).

CONCLUSION

Our results showed GDF-15 upregulation in the non-dipper HT group. GDF-15 and nighttime diastolic BP were independently associated with the non-dipping pattern. This study may suggest possible utilization of GDF-15 in the prediction of non-dipper HT.

Renal resistive index and aortic knob width relationship as a predictor of renal prognosis in essential hypertension

The scientific studies that have been conducted so far highlight that renal resistive index (RI) and aortic knob width (AKW) indicate poor prognosis regarding renal and cardiovascular mortality. But the existence of a direct relationship RI and AKW is unclear. This study aims investigating the relationship between RI and the measured AKW in chest radiography of the patients with hypertensive nephropathy who do not require renal replacement therapy.This prospective study included 268 consecutive patients with essential hypertension. Patients were divided into 2 groups as RI ≥0.7 and RI <0.7. The ROC curve, sensitivity, and specificity ratios were evaluated to determine which AKW value is the best predictive one for the RI ≥0.7.The cutoff point of AKW was evaluated as ≥36 for the cases with RI ≥0.7: sensitivity was 71.22%; specificity was 71.32%; the positive predictive value (PPV) was 72.79; the negative predictive value (NPV) was 69.70, and the accuracy was 71.27. Area under the ROC curve ± standard error (AUC ± SE) = 0.729 ± 0.031 (P < .001).AKW can provide important predictive information about the subclinical renal dysfunction in hypertensive patients with RI ≥0.7. Moreover; AKW is a predictive factor for both the diagnostic and prognostic evaluation of renal pathologies.

Relationship between Sleep Duration and Risk Factors for Stroke

Stroke is a leading cause of death and disability worldwide. While various risk factors have been identified, sleep has only been considered a risk factor more recently. Various epidemiologic studies have associated stroke with sleep such as sleep duration, and laboratory and clinical studies have proposed various underlying mechanisms. The pathophysiology is multifactorial, especially considering sleep affects many common risk factors for stroke. This review aims to provide an outline of the effect of sleep duration on common stroke risk factors. Appropriate sleep duration, especially in patients who have stroke risk factors, and increasing awareness and screening for sleep quality may contribute to primary prevention of stroke.

Ambulatory Blood Pressure Monitoring in Chinese Patients with Obstructive Sleep Apnea

STUDY OBJECTIVES

Nocturnal blood pressure (BP) dipping in patients with obstructive sleep apnea (OSA) has not yet been well investigated in Chinese patients, in whom the relationship of OSA and body mass index (BMI) is weaker than that in Caucasians. The aim of this study was to evaluate the BP profile, and the relationships between nocturnal BP and the severity of OSA, in Chinese patients.

METHODS

Consecutive Chinese adult outpatients with suspected OSA had overnight polysomnography (PSG), office BP, and 24-h ambulatory BP monitoring (ABPM). The apnea-hypopnea index (AHI) and nocturnal oxygen saturation level were recorded, and BP patterns were classified based on the ABPM.

RESULTS

Fifty-six subjects (40 male and 16 female, 48.59 ± 13.27 y) were evaluated. There were 14 patients with mild OSA (25.0%, AHI: 10.56 ± 3.42 events/h), 16 with moderate OSA (28.6%, AHI: 23.536 ± 3.42 events/h) and 26 with severe OSA (46.4%, AHI: 51.52 ± 3.42 events/h). There were 18 dippers (32.1%), 27 non-dippers (48.2%), and 11 reverse dippers (19.6%). As OSA severity increased, non-dipping also increased. A total of 67.9% of the OSA patients showed overall hypertension on ABPM, 57.1% had daytime hypertension only, and 73.2% had nighttime hypertension.

CONCLUSIONS

OSA severity is associated with 24-h BP profiles in a population with only mild increases in BMI. These results can influence clinical practice, OSA management, and hypertension treatment policies.

Blood pressure reverse dipping may associate with stable coronary artery disease in patients with essential hypertension: a cross-sectional study

The dipping variations of circadian blood pressure (BP) correlate closely with target-organ damages and cardiovascular events. The aim of this study was to investigate the relationship between BP reverse dipping and the prevalence of stable coronary artery disease (sCAD) in hypertensive patients. Clinical data and the results of 24-hour ambulatory BP monitoring (ABPM) were obtained from 718 hypertensive patients (390 males, mean age 59.6 ± 13.8 years) in a single centre in Northern China. Reverse dipping pattern was defined as nocturnal systolic BP (SBP) was higher than daytime SBP. A logistic regression model was applied to explore the independent risk factors of sCAD. The patients with BP reverse dipping accounted for 31.5% in sCAD group and 19.5% in control group (P < 0.05). In multivariate analysis, BP reverse dipping remained significantly associated with the prevalence of sCAD (Odds ratio [OR], 1.772; p = 0.027). Furthermore, the circadian decline rate of SBP was independently associated with sCAD (OR, 0.975; p = 0.043). The hypertensive patients with reverse BP dipping were found to be more frequently suffering from sCAD. BP reverse dipping examined with 24-hour ABPM may indicate sCAD.

Association among epicardial fat, heart rate recovery and circadian blood pressure variability in patients with hypertension

Background

Epicardial fat tissue is known to have an unique endocrine function which affect the cardiac autonomic system. Heart rate recovery (HRR) is a simple non-invasive measurement that assesses autonomic nervous system dysfunction. We aimed to investigate the association among epicardial fat thickness (EFT), HRR and circadian blood pressure (BP) variation in patients with hypertension.

Methods

A total of 358 consecutive patients who underwent both 24-hour ambulatory BP monitoring (ABPM) and a treadmill test were enrolled. Echocardiographic EFT and HRR, defined as peak heart rate minus heart rate after a 1-min recovery time, were measured. Patients were classified according to the ABPM; 147 patients with hypertension with a dipping pattern at night (dippers), 140 patients with hypertension with a non-dipping pattern at night (non-dippers) and 71 normotensive controls.

Results

EFT was significantly higher in hypertensive patients, especially in the non-dipper group, compared to the controls (non-dippers, 7.5 ± 2.9 mm; dippers, 6.6 ± 1.6 mm; controls, 5.5 ± 2.1 mm; p < 0.001). HRR was significantly lower in both hypertensive groups as compared to the control group and was the lowest in the non-dipper group (non-dipper, 26.6 ± 18.6; dipper, 29.5 ± 21.5; control, 71.4 ± 19.8; p < 0.001). EFT was significantly correlated with age, body mass index, 24-hour mean systolic BP and 24 h mean BP variability, whereas exercise duration, metabolic equivalents (METs) and HRR were inversely correlated with EFT. Furthermore, EFT > 6.7 mm was associated with a blunted HRR with 76 % sensitivity and 61 % specificity (ROC area under curve: 0.71, 95 % confidence interval, CI = 0.65–0.76, p < 0.001). In a multivariate analysis, EFT (odds ratio, OR = 3.53, 95 % CI = 1.20–10.37, p = 0.022) and 24-hour mean BP variability (OR = 1.09, 95 % CI = 1.03–1.16, p = 0.005) were independent predictors of a blunted HRR defined as HRR ≤ 12 beats (n = 63) in patients with hypertension.

Conclusion

EFT and HRR were significantly correlated with circadian BP variability in patients with hypertension. EFT and circadian BP variability were independent predictors of blunted HRR, which suggests a link between epicardial fat and autonomic dysregulation in hypertension.

Prognostic Significance of Neuroadrenergic Dysfunction for Cardiovascular Events in Patients With Acute Myocardial Infarction

BACKGROUND

The dysregulation of systemic blood pressure (BP) variation or cardiac neuroadrenergic dysfunction is associated with adverse cardiovascular events. We aimed to clarify the prognostic significance of neuroadrenergic dysfunction for cardiovascular events in patients with acute myocardial infarction (AMI).

METHODS AND RESULTS

We enrolled 63 AMI patients (mean age, 67±12 years) underwent ambulatory BP monitoring (ABPM) and cardiac iodine-(123)metaiodobenzylguanidine (MIBG) imaging within 4 weeks after AMI onset. We analyzed the circadian BP pattern and heart-to-mediastinum (H/M) MIBG uptake ratio. All the patients were followed for 2 years. The study endpoint was a composite of major adverse cardiovascular events, including all-cause death, MI, coronary revascularization except for the MI culprit lesion, and stroke. Patients with a non-dipper pattern (n=29) or an H/M ratio <1.96 (n=28) had a worse prognosis than those with either a dipper pattern (n=34) or an H/M ratio ≥1.96 (n=35; log-rank, P=0.013 and 0.010, respectively). Patients with both a non-dipper pattern and an H/M ratio <1.96 (n=12) had a significantly worse prognosis than did the other patients (P=0.0020).

CONCLUSIONS

Dysregulation of BP variation and cardiac MIBG uptake were associated with cardiovascular events following AMI. Examining ABPM with MIBG imaging may potentially improve risk stratification in these patients.

Effects of Carotid Stenting on Nocturnal Nondipping Phenomenon

BACKGROUND

It is well known that nondipper blood pressure (BP) pattern is associated with an increased cardiovascular risk in hypertensive patients. The aim of this study is to observe whether carotid artery stent (CAS) procedure returns nondipper BP pattern to dipper pattern in hypertensive patients.

METHODS

Ambulatory BP monitorization (ABPM) was performed in 152 hypertensive patients who underwent CAS procedure 1 day before, and 1 day and 1 year after the procedure. BP monitorization of patients was classified as dipper and nondipper. BP parameters 1 year after CAS procedure were compared with preprocedure parameters.

RESULTS

According to baseline ambulatory BP follow-ups, a total of 152 hypertensive patients with 122 (80%) nondippers and 30 (20%) dippers were enrolled in this study. According to ABPM results 1 year after CAS procedure, 78 patients (64%) who had nondipper pattern at first transformed into dipper pattern and 44 patients (36%) remained to be nondippers. Moreover, 1 year after CAS procedure, 18 patients (60%) who had dipper pattern at first transformed into nondipper pattern and 12 patients (40%) remained as dippers. When BP follow-up values at 1 year after CAS procedure were compared with BP readings before the procedure, 78 patients (51%) who were nondipper before the procedure transformed into dipper pattern (P ≤ .01), whereas 44 patients (29%) with nondipper pattern remained to be nondippers (P = .01). Twelve patients (7.9%) who had dipper pattern remained to have dipper pattern (P = .768). Eighteen patients who had dipper pattern (12%) transformed into nondipper pattern after the procedure (P < .01). The total number of nondipper pattern patients before CAS procedure was 80.3% (122 patients), whereas this percentage dropped to 40.8% (62 patients) after the CAS procedure (P < .01).

CONCLUSIONS

During 1-year follow-up after CAS procedure, nondipper BP pattern transforms into dipper pattern. This result might be attributed to the contributory effect of CAS procedure to long-term cardiovascular protection.

Circadian metabolism in the light of evolution

Circadian rhythm, or daily oscillation, of behaviors and biological processes is a fundamental feature of mammalian physiology that has developed over hundreds of thousands of years under the continuous evolutionary pressure of energy conservation and efficiency. Evolution has fine-tuned the body's clock to anticipate and respond to numerous environmental cues in order to maintain homeostatic balance and promote survival. However, we now live in a society in which these classic circadian entrainment stimuli have been dramatically altered from the conditions under which the clock machinery was originally set. A bombardment of artificial lighting, heating, and cooling systems that maintain constant ambient temperature; sedentary lifestyle; and the availability of inexpensive, high-calorie foods has threatened even the most powerful and ancient circadian programming mechanisms. Such environmental changes have contributed to the recent staggering elevation in lifestyle-influenced pathologies, including cancer, cardiovascular disease, depression, obesity, and diabetes. This review scrutinizes the role of the body's internal clocks in the hard-wiring of circadian networks that have evolved to achieve energetic balance and adaptability, and it discusses potential therapeutic strategies to reset clock metabolic control to modern time for the benefit of human health.

New inflammatory markers for prediction of non-dipper blood pressure pattern in patients with essential hypertension: Serum YKL-40/Chitinase 3-like protein 1 levels and echocardiographic epicardial adipose tissue thickness

The aim of the present study was to investigate whether YKL-40 levels and epicardial adipose tissue (EAT) thickness were associated with non-dipping pattern in essential hypertension (HT). Age- and sex-matched 40 dipper hypertensive patients and 40 non-dipper hypertensive patients were included in the study. Non-dippers had significantly increased EAT thickness and higher YKL-40 and high-sensitivity C-reactive protein levels than dippers. Multivariate logistic regression analysis showed that the EAT thickness and serum levels of YKL-40 and high-sensitivity C-reactive protein were independent predictors of non-dipping pattern in essential HT. In essential HT, presence of non-dipping pattern is associated with increased inflammatory response.

Blood pressure reverse-dipping is associated with early formation of carotid plaque in senior hypertensive patients

Nocturnal variations in blood pressure (BP) were associated with carotid intima-media thickness. However, the precise relationship between circadian variations of BP and carotid plaques remains unknown. Therefore, the prognostic value of reverse-dipper pattern of BP for carotid plaque was investigated. In this cross-sectional study, a total of 524 hypertensive patients were recruited and evaluated with ambulatory BP monitoring between April 2012 and June 2013. Carotid plaque was classified into Grade 0 (normal or no observable plaque), Grade 1 (mild stenosis, 1%-24% narrowing), and Grade 2 (moderate stenosis, ≥25% narrowing). Multinomial logistic regression was applied to analyze the relationship between different degrees of carotid plaque and ambulatory BP monitoring results. Reverse-dipper pattern of BP was more common in older patients, smokers, and those with elevated fasting glucose. The incidences of coronary artery disease, lacunar infarction, and diabetes were also higher among hypertensive with reverse-dipper pattern. Multinomial logistic regression analysis showed that reverse dipper (odds ratio [OR] 2.500; 95% confidence interval [CI] 1.320-4.736; P = 0.005), age (OR 1.089; 95% CI 1.067-1.111; P < 0.001), smoke (OR 1.625; 95% CI 1.009-2.617; P = 0.046), and diabetes (OR 1.759; 95% CI 1.093-2.830; P = 0.020) were significantly different between mild carotid plaque and normal. Our results also suggested that mild carotid plaque was closely related to reverse-dipper pattern of BP (2.308; 95% CI 1.223-4.355; P = 0.010). Reverse-dipper pattern of BP may be a risk factor for carotid atherosclerosis and play a crucial role in the early formation of carotid plaque.

Chronically implanted pressure sensors: challenges and state of the field

Several conditions and diseases are linked to the elevation or depression of internal pressures from a healthy, normal range, motivating the need for chronic implantable pressure sensors. A simple implantable pressure transduction system consists of a pressure-sensing element with a method to transmit the data to an external unit. The biological environment presents a host of engineering issues that must be considered for long term monitoring. Therefore, the design of such systems must carefully consider interactions between the implanted system and the body, including biocompatibility, surgical placement, and patient comfort. Here we review research developments on implantable sensors for chronic pressure monitoring within the body, focusing on general design requirements for implantable pressure sensors as well as specifications for different medical applications. We also discuss recent efforts to address biocompatibility, efficient telemetry, and drift management, and explore emerging trends.

Circadian influences on myocardial infarction

Components of circadian rhythm maintenance, or "clock genes," are endogenous entrainable oscillations of about 24 h that regulate biological processes and are found in the suprachaismatic nucleus (SCN) and many peripheral tissues, including the heart. They are influenced by external cues, or Zeitgebers, such as light and heat, and can influence such diverse phenomena as cytokine expression immune cells, metabolic activity of cardiac myocytes, and vasodilator regulation by vascular endothelial cells. While it is known that the central master clock in the SCN synchronizes peripheral physiologic rhythms, the mechanisms by which the information is transmitted are complex and may include hormonal, metabolic, and neuronal inputs. Whether circadian patterns are causally related to the observed periodicity of events, or whether they are simply epi-phenomena is not well established, but a few studies suggest that the circadian effects likely are real in their impact on myocardial infarct incidence. Cycle disturbances may be harbingers of predisposition and subsequent response to acute and chronic cardiac injury, and identifying the complex interactions of circadian rhythms and myocardial infarction may provide insights into possible preventative and therapeutic strategies for susceptible populations.

Management of sleep apnea in the neurology patient: Five new things

Recognizing and treating sleep-disordered breathing (SDB) is essential in delivering neurologic care due to its association with a growing list of neurologic conditions (e.g., stroke, neurodegenerative disorders). Thus, increased proficiency in the recognition and management of SDB is likely to result in better outcomes, care, and utilization of health care resources. To date, continuous positive airway pressure remains the gold standard for patients with moderate to severe obstructive sleep apnea and has been shown to be effective in treating variations of SDB. Appropriate application of new methods and technology such as home sleep testing can help bridge the gap between the need and supply for sleep health care and delivery. Increased focus on efficacious strategies to further awareness and education for patients, caretakers, and providers is paramount to long-term adherence to treatment.

Sphingomyelin levels in nondipper and dipper hypertensive patients

A number of studies have focused on the association between sphingomyelin (SM) levels and atherosclerosis, however, there are few data concerning the correlation of SM with nondipper hypertension. The present study aimed to investigate the correlation between plasma SM levels and nondipper status in patients with hypertension. A total of 200 hypertensive patients were enrolled and divided into two groups according to their ambulatory blood pressure monitoring (AMBP) results: Dipper group (84 patients) and nondipper group (116 patients). All patients were subjected to transthoracic echocardiography examination and laboratory tests. No statistically significant difference was observed between the two groups in terms of basic clinical characteristics. However, the plasma SM levels in the dipper group were significantly lower than those of the nondipper group (41.9±17.5 vs. 96.4±14.3 mg/dl, P=0.003). The left ventricular mass index (LVMI) was higher in the nondipper patients than in the dipper patients and the diastolic function parameters in the nondipper patients were less favorable. Correlation analysis showed that the SM level was negatively correlated with the magnitude of systolic blood pressure (SBP) fall at night (r=−0.42, P<0.01) and diastolic blood pressure (DBP) fall at night (r=−0.31, P<0.01). The nondipper status had contributory effects on hypertensive concentric hypertrophy and diastolic function impairment. In addition, the plasma SM level was associated with a nondipper pattern of hypertension.

Aortic stiffness and hypotension episodes are associated with impaired cognitive function in older subjects with subjective complaints of memory loss

OBJECTIVE

Though CV risk factors and markers of arterial aging are recognized risky for cognition, no study has simultaneously investigated the impact of multiple cardiac, arterial (large and small vessels), and hemodynamic parameters on cognitive function in older subjects.

METHODS

Two hundred eighty older subjects with subjective complaints of memory loss and no previous stroke (mean age 78.3 ± 6.3 years) were studied. Global cognitive function was evaluated with the Mini-Mental State Examination (MMSE). Cognitive impairment was defined as a MMSE < 21. We measured: traditional CV risk factors; aorta stiffness (Pulse Wave Velocity, PWV); LV mass; presence of WML at neuroimaging; episodes of hypotension (SBP <100 mmHg during 24 h Ambulatory Blood Pressure Monitoring).

RESULTS

In both cross-sectional and longitudinal analyses PWV, WML, and episodes of hypotension were significantly associated with poorer cognitive function-controlling for age, sex, education, depression, traditional CV risk factors, and medications. LV mass was no longer associated with cognition in multiple regression. Older subjects with stiffer arteries or episodes of hypotension presented a 4-fold and an 11-fold, respectively, greater odds for progression from normal cognitive function to cognitive impairment. A synergistic effect between PWV, WML, and hypotension was observed: the occurrence of any two of PWV, WML, or hypotension was accompanied by lower MMSE; in the presence of all three factors, a further significant decline in cognitive function was observed.

INTERPRETATION

Systemic hemodynamic parameters (higher PWV and hypotension) together with cerebral microvascular damage (WML) are significantly associated with poorer cognitive function and may identify older subjects with subjective complaints of memory loss at higher risk of cognitive decline.

Night/day ratios of ambulatory blood pressure among healthy adolescents: roles of race, socioeconomic status, and psychosocial factors

BACKGROUND

Elevated nighttime blood pressure (BP) predicts hypertension and its complications in adulthood.

PURPOSE

This study aimed to assess the independent effects of race and family income on night/day BP among adolescents and to examine whether negative emotions, low positive resources, and unpleasant interactions during the day are also related.

METHODS

Healthy African American and Caucasian high school students (N = 239) wore an ambulatory BP monitor for 48 h, recorded quality of ongoing interpersonal interactions, and completed questionnaires.

RESULTS

African Americans and those with lower family income had higher night/day BP ratios. African Americans reporting greater negative emotions, lower positive resources, and more unpleasant interactions had higher night/day BP ratios.

CONCLUSIONS

Racial differences in night BP emerge by adolescence, independent of family income. African Americans, especially those high in negative emotions and low in positive resources, may be at higher relative risk for hypertension later in life in part due to elevated night BP.

Stress, cortisol, and nighttime blood pressure dipping in nonhypertensive Black American women

Black American women have among the highest hypertension (HTN) rates in the world. Research suggests that nighttime might be a critical period of vulnerability for the development of HTN in Blacks. In the present study, personal factors (age, body fat, income, family history), psychological factors (stress, emotions, and John Henryism), and physiological factors (salivary cortisol and blood pressure [BP]) were explored in 30 Black women, ages 26-51 years. Data were collected in participants' homes. BP was monitored while participants were awake and asleep. Cortisol samples were obtained within the first hour after awakening. The usual pattern for BP is a drop or dipping of 10-20% during sleep; however, the BP for about a third of the subjects did not dip adequately during sleep. Though not statistically significant, this nondipping was clinically relevant and was associated with positive family history of HTN, more stress, lower positive and higher negative affect scores, and higher early morning cortisol levels. These findings add to the HTN risk profile and support the need to further explore the relationship between nondipping nighttime BP and cardiovascular disease in Black women.

Ambulatory arterial stiffness index and nocturnal blood pressure dipping in pregnancies complicated by hypertension

BACKGROUND

The study sets out to examine differences in arterial stiffness and nocturnal blood pressure dipping as outcomes in women with gestational hypertension compared with healthy pregnant women during pregnancy and 3 months after delivery.

METHODS AND RESULTS

We prospectively studied a cohort of 60 women during the third trimester of pregnancy; of them, 28 suffered pregnancy-induced hypertension or pre-eclampsia and 32 had uncomplicated singleton pregnancies. Subsequently, 42 of these were re-examined 3 months after delivery. In women with a hypertensive disorder, the nocturnal fall in blood pressure (dipping) was significantly smaller than in the normotensive group (systolic, P = 0·031; diastolic, P<0·001), but after pregnancy, this difference disappeared (systolic, P = 0·941; diastolic, P = 0·907). Ambulatory arterial stiffness index (AASI) assessed after pregnancy correlated inversely with fasting glucose level during pregnancy (r = -0·580, P = 0·018), both systolic (r = -0·651, P = 0·012) and diastolic (r = -0·687, P = 0·007) nocturnal dipping and total cholesterol concentration after pregnancy (r = -0·526, P = 0·036).

CONCLUSIONS

A hypertensive disorder during pregnancy was associated with a flattened circadian blood pressure response, which was restored after delivery. Higher arterial stiffness predicted the signs of postpartum metabolic syndrome and correlated also with non-dipping, especially postpartum.

Nighttime blood pressure and white matter hyperintensities in patients with Parkinson disease

Increasing evidence indicates that nocturnal blood pressure level and/or loss of nocturnal blood pressure dips are sensitive markers of cardiovascular morbidity and mortality. Several studies have suggested that blunted heart rate variability and nocturnal decline in heart rate are also associated with target organ damage. These phenomena occur relatively commonly in patients with Parkinson disease (PD); however, few studies have assessed the consequences of these abnormalities in patients with PD. We investigated the influence of circadian changes in blood pressure and heart rate on white matter hyperintensities (WMHs) in patients with PD. The presence of nocturnal hypertension was associated with increased WMH score, and nighttime systolic pressure was closely related with white matter changes. Blunted heart rate variability and nocturnal decline in heart rate were also related to increasing WMH scores. The non-dipping phenomenon did not influence WMHs. These findings suggest that white matter changes are related to circadian autonomic dysfunction, particularly nocturnal hypertension in patients with PD. Therefore, it is important to monitor nocturnal blood pressure status, because modifying these circadian regulatory disturbances can be beneficial to protect against vascular brain damage in patients with PD.

Design and In Vitro Evaluation of Compression-coated Pulsatile Release Tablets of Losartan Potassium

In majority of individuals blood pressure rises in the early morning hours, which lead to serious cardiovascular complications. Formulation of pulsatile system makes it possible to deliver drug at definite period of time when symptoms of the disease condition are most critical. The purpose of the present work was to develop pulsatile release tablet of losartan potassium for chronotherapy in hypertension. The prepared system consisted of a core tablet coated with versatile and safe hydrophilic cellulosic ethers such as, hydroxypropyl methylcellulose, hydroxypropyl cellulose and sodium carboxy methylcellulose to produce burst release after predetermined lag time. Various formulation factors were studied through series of test and in vitro dissolution study. It was found that core tablets containing superdisintegrant failed to produce burst drug release pattern while effervescent agent was able to do so. Results also reveal that coating composition and coating level affects lag time. Formulation containing effervescent agent in core and coated with 200 mg hydroxypropyl cellulose provide lag time of 4.5 h with 73% drug release in 6 h that followed a sigmoidal release pattern. These values were close to the desired objective of producing lag time of 5-6 h followed by fast drug release. This approach can thus provide a useful means for timed release of losartan and is helpful for patients with morning surge.

Need for insulin to control gestational diabetes is reflected in the ambulatory arterial stiffness index

BACKGROUND

The aim was to evaluate the metabolic profile in conjunction with vascular function using the ambulatory arterial stiffness index (AASI) in women with uncomplicated pregnancies and in women with gestational diabetes mellitus (GDM).

METHODS

Plasma glucose, lipids, HOMA -IR (homeostasis model assessment of insulin resistance) and AASI, as obtained from 24-hour ambulatory blood pressure monitoring in third trimester pregnancy and at three months postpartum, were measured in three groups of women: controls (N=32), women with GDM on diet (N=42) and women with GDM requiring insulin treatment (N=10).

RESULTS

Women with GDM had poorer glycemic control and higher HOMA-IR during and after pregnancy and their total and LDL (low density lipoprotein) cholesterol levels were significantly higher after pregnancy than in the controls. After delivery, there was an improvement in AASI from 0.26±0.10 to 0.17±0.09 (P=0.002) in women with GDM on diet, but not in women with GDM receiving insulin whose AASI tended to worsen after delivery from 0.30±0.23 to 0.33±0.09 (NS), then being significantly higher than in the other groups (P=0.001-0.047).

CONCLUSIONS

Women with GDM had more unfavorable lipid profile and higher blood glucose values at three months after delivery, the metabolic profile being worst in women requiring insulin. Interestingly, the metabolic disturbances at three months postpartum were accompanied by a tendency towards arterial stiffness to increase in women requiring insulin.

Can acupuncture affect the circadian rhythm of blood pressure? A randomized, double-blind, controlled trial

OBJECTIVES

The objective of the study was to investigate the effect of acupuncture on the circadian rhythm of blood pressure (BP) in patients with hypertension.

DESIGN

The study was designed as a randomized, double-blind, controlled trial. Subjects were randomly divided into an active acupuncture group and a sham acupuncture group. Each patient received real or sham acupuncture treatment twice a week for 8 weeks. Acupuncture needles were inserted at bilateral ST 36 plus PC 6; placebo points.

SUBJECTS

Thirty-three (33) patients with essential hypertension were the subjects.

OUTCOME MEASURES

Twenty-four (24)-hour ambulatory BP was assessed before and after treatment.

RESULTS

After the treatment period, there was a significant increase in nocturnal diastolic BP dipping compared to that at baseline (10.20±7.56 mm Hg versus 5.21±10.19 mm Hg, p=0.038) in the active acupuncture group but not in the sham acupuncture group. The nocturnal diastolic BP dipping response to active acupuncture treatment was significantly different from the response seen with the sham acupuncture treatment (p=0.041). The number of dippers also increased from 4 to 8 in the active acupuncture group. Average systolic and diastolic BP was not changed significantly except for nighttime diastolic BP (90.32±11.47 mm Hg to 87.83±9.16 mm Hg, p=0.041).

CONCLUSIONS

It is suggested that acupuncture treatment could be useful for improving the circadian rhythm of BP in patients with hypertension.

Heart rate recovery: a practical clinical indicator of abnormal cardiac autonomic function

The autonomic nervous system (ANS) and cardiovascular function are intricately and closely related. One of the most frequently used diagnostic and prognostic tools for evaluating cardiovascular function is the exercise stress test. Exercise is associated with increased sympathetic and decreased parasympathetic activity and the period of recovery after maximum exercise is characterized by a combination of sympathetic withdrawal and parasympathetic reactivation, which are the two main arms of the ANS. Heart rate recovery after graded exercise is one of the commonly used techniques that reflects autonomic activity and predicts cardiovascular events and mortality, not only in cardiovascular system disorders, but also in various systemic disorders. In this article, the definition, applications and protocols of heart rate recovery and its value in various diseases, in addition to exercise physiology, the ANS and their relationship, will be discussed.

Sleep disorders and stroke

The purpose of this review is to highlight existing literature on the epidemiology, pathophysiology, and treatments of stroke sleep disorders. Stroke sleep disorders are associated with many intermediary vascular risk factors leading to stroke, but they may also influence these risk factors through direct or indirect mechanisms. Sleep disturbances may be further exacerbated by stroke or caused by stroke. Unrecognized and untreated sleep disorders may influence rehabilitation efforts and poor functional outcomes following stroke and increase risk for stroke recurrence. Increasing awareness and improving screening for sleep disorders is paramount in the primary and secondary prevention of stroke and in improving stroke outcomes. Many vital questions about the relationship of sleep disorders and stroke are still unanswered and await future well-designed studies.

Afternoon blood pressure increase: a blood pressure pattern associated with microvascular complications in type 2 diabetes mellitus

BACKGROUND

Minor blood pressure (BP) alterations detected by ambulatory BP monitoring (ABPM) was associated with microvascular disease in type 2 diabetes mellitus (DM). We examined whether a previously described afternoon BP peak is linked to hypertension status and associated with microvascular complications.

METHODS

A cross-sectional study was conducted with 207 type 2 DM patients (56 years, 52.7% men). ABPM was determined by oscillometry.

RESULTS

An increase in both systolic and diastolic BP occurred in the afternoon; the same pattern was observed across hypertension categories (normotensive, prehypertensive, or hypertensive). We calculated BP increase for the period between 2 and 8 PM as the difference between mean BP at 8 PM and mean BP at 2 PM (calculated by the average of four measurements in each hour). The cohort was then divided into two groups (afternoon BP increase below or above the group's median). The prevalence of diabetic retinopathy (DR) was higher in those with afternoon increment above the group median for both systolic (50 vs. 30%, P = 0.004) and diastolic (47 vs. 33%, P = 0.04) BP. For systolic BP, this result was maintained after adjustments for age, gender, A1c test, DM duration, total cholesterol, and 24-h systolic BP. Afternoon BP increments for both systolic and diastolic BP correlated significantly with urinary albumin excretion rate (UAER) after adjusting for 24-h BP (systolic: r = 0.17, P = 0.01; diastolic: r = 0.16, P = 0.02). However, when adjusted for all covariates, these correlations were no longer significant.

CONCLUSIONS

An increment in afternoon BP was observed in type 2 diabetic patients regardless of hypertension status; that increment was associated with higher prevalence of DR but not diabetic nephropathy independently of measured confounders.

Efficacy of an olmesartan medoxomil-based treatment algorithm in patients with hypertension and type 2 diabetes: analysis of diurnal blood pressure control as assessed by 24-hour ambulatory blood pressure monitoring

Objective: Secondary, prespecified analysis of a single-arm, open-label study evaluating the efficacy of olmesartan medoxomil (OM) plus hydrochlorothiazide (HCTZ) in patients with hypertension and type 2 diabetes.

Methods: After placebo run-in, 192 patients received OM 20 mg/day for 3 weeks. If blood pressure (BP) remained ≥120/70 mmHg, patients were uptitrated every 3 weeks to OM 40 mg/day, OM/HCTZ 40/12.5 mg/day, and OM/HCTZ 40/25 mg/day. Efficacy was evaluated by 24-hour ambulatory BP monitoring. Secondary endpoints included changes in ambulatory systolic BP (SBP) and diastolic BP (DBP) during daytime (08:00 to 16:00) and nighttime (22:00 to 06:00), as well as achievement of prespecified ambulatory BP targets in the total cohort and subgroups based on gender, race, hypertension severity, and age (≥65 or <65 years). Dipper status (nocturnal decrease in BP ≥10% of mean daytime BP) was assessed.

Results: At baseline, mean ambulatory BP was 151.2 ± 12.7/87.6 ± 9.0 mmHg during the daytime and 140.3 ± 13.1/78.1 ± 8.6 mmHg during the nighttime. Mean daytime and nighttime ambulatory BP was reduced from baseline by 22.3 ± 13.7/12.0 ± 8.9 mmHg and 18.8 ± 12.4/ 10.2 ± 7.2 mmHg, respectively. The reduction in daytime ambulatory SBP was 24.4 ± 11.8 mmHg in Blacks, 21.7 ± 14.2 mmHg in non-Blacks, 23.6 ± 12.3 mmHg in females, 21.2 ± 14.8 mmHg in males, 23.4 ± 11.6 mmHg in patients aged ≥65 years, and 21.9 ± 14.4 mmHg in those aged <65 years. Ambulatory BP targets of <130/80, <125/75, and <120/80 mmHg were reached by 51.7%, 36.0%, and 32.6% of patients during the daytime and 69.8%, 60.5%, and 50.6% of patients during the nighttime. After 12 weeks of treatment, 36.4% of baseline nondippers converted to dippers.

Conclusions: OM ± HCTZ effectively lowered ambulatory BP in patients with type 2 diabetes and hypertension, enabling them to achieve ambulatory BP targets during both the daytime and nighttime.

Valsartan: more than a decade of experience

Valsartan is a nonpeptide angiotensin receptor antagonist that selectively blocks the binding of angiotensin II to the angiotensin II type 1 receptor. The efficacy, tolerability and safety of valsartan have been demonstrated in large-scale studies in hypertension, heart failure (HF) and post-myocardial infarction (MI). This review focuses on what was learned from the valsartan clinical research programme and other comparative trials published from 1997 to the present. Many studies have demonstrated the efficacy of valsartan in lowering blood pressure (BP) in a variety of patient populations (including elderly, women, children, obese patients, patients with diabetes mellitus, patients with chronic kidney disease [CKD], patients at high risk of cardiovascular [CV] disease, African Americans, Hispanic Americans and Asians) and in improving outcomes in CV disease and CKD. In hypertension, valsartan exhibits dose-dependent efficacy in reducing both systolic and diastolic BP over the once-daily dose range of 80-320 mg; doses as high as 640 mg/day have been studied and found to be efficacious and safe. BP control can be enhanced with a more consistent 24-hour BP-lowering profile by using single-pill, fixed-dose combination therapy with valsartan plus hydrochlorothiazide (HCTZ). The cardioprotective benefits of valsartan have been demonstrated in large-scale outcome trials and include significant reductions in CV morbidity and mortality in HF, following MI, and in patients with co-morbid hypertension and coronary artery disease and/or HF; reductions in HF hospitalizations; and reductions in the incidence of stroke. The magnitude of these effects is comparable with that demonstrated with angiotensin-converting enzyme (ACE) inhibitors; however, valsartan has a more favourable tolerability profile, with a significantly lower incidence of cough and only rare reports of angio-oedema, both class effects of ACE inhibitor use. Consistent with its angiotensin receptor-blocking effects, valsartan also reduces circulating levels of biochemical markers that are associated with angiotensin II-mediated endothelial dysfunction and CV risk (e.g. high-sensitivity C-reactive protein or oxidized low-density lipoprotein). Improvements in CKD with valsartan include statistically and clinically meaningful reductions in urinary albumin and protein excretion in patients with type 2 diabetes and in nondiabetic patients with CKD. In short-term studies, valsartan has improved or stabilized various indices of metabolic function in at-risk patients, including those with co-morbid hypertension, obesity and/or metabolic syndrome. Because of this, valsartan is being prospectively investigated for its ability to reduce the incidence of new-onset diabetes and provide cardioprotection in patients with impaired glucose tolerance. Valsartan and valsartan/HCTZ are well tolerated. In clinical trials, adverse events during valsartan treatment were similar to those occurring with placebo. The combination of valsartan/HCTZ was better tolerated than HCTZ alone. Valsartan is administered once daily for hypertension; doses are usually taken upon awakening. In patients with HF or MI, valsartan is administered twice daily.