Circadian Blood Pressure Changes Research Articles

The relationship between the systemic immune-inflammation index and reverse-dipper circadian pattern in newly diagnosed hypertensive patients.

Although hypertension is considered high intravascular pressure, impairing circadian blood pressure (BP) has been shown to potentially contribute to poor clinical outcomes. Systemic immune-inflammation index (SII), based on platelet, neutrophil, and lymphocyte counts, has been established as a strong prognostic marker in cardiovascular disease. The role of inflammation in the pathogenesis of hypertension is a well-known issue and inflammatory markers are associated with BP variability. We aimed to investigate whether there is a relationship between circadian BP changes and SII in newly diagnosed hypertensive patients. The study population consisted of 196 newly diagnosed hypertensive patients without LVH. In total, 76 (38%) patients had a dipper BP pattern, 60 (31%) patients had a non-dipper BP pattern, and 60 (31%) patients had a reverse-dipper BP pattern. SII was calculated according to Multivariate logistic regression analysis revealed SII and HDL-C as an independent predictors of reverse-dipper circadian pattern in newly diagnosed hypertensive patients. The cut-off value of the SII for reverse-dipper hypertension in a ROC curve analysis was>639.73with 63.3% sensitivity and 84.2% specificity. Our study showed that the SII level was higher in the reverse-dipper hypertension patient group than in the dipper and non-dipper hypertension groups. Furthermore, SII was an independent predictor of newly diagnosed reverse-dipper hypertensive patients. The high SII value in newly diagnosed hypertensive patients can be used as an early warning parameter to identify reverse-dipper hypertension patients.

Changes in Circadian Variations in Blood Pressure, Pain Pressure Threshold and the Elasticity of Tissue after a Whole-Body Photobiomodulation Treatment in Patients with Fibromyalgia: A Tripled-Blinded Randomized Clinical Trial.

This study analysed circadian variation changes in blood pressure (BP), the pain pressure threshold (PPT) and the elasticity of tissue in patients with fibromyalgia (FM) after a whole-body photobiomodulation (PBM) treatment. This was a tripled-blinded randomized clinical trial including forty participants with FM. Participants using validated self-measurement BP devices attained readings that were used to calculate the circadian variation. Additionally, a standard pressure algometer of 1cm2 was used to assess 13 tender points by exerting a pressure of up to 4 kg, and strain elastography assessed the elasticity of tissue. Circadian variations in BP showed significant differences after the PBM intervention (p = 0.036). When comparing PPT between groups, statistically significant differences were found in the occiput (p = 0.039), low cervical (p = 0.035), trapezius (p = 0.037), second rib (p < 0.001) and medial epicondyle points (p = 0.006). Furthermore, there were statistically significant differences in both the trapezius and the forearm at the distal dorsal third SEL values (p ≤ 0.001) when comparing groups. Whole-body PBM produces changes in circadian blood pressure, the pain pressure threshold and the elasticity of tissue after a treatment program was carried out. However, more studies are needed to corroborate our findings as well as to better understand the underlying mechanisms.

Optimization of blood pressure measurement practices for pharmacodynamic analyses of tyrosine-kinase inhibitors.

Blood pressure measurements form a critical component of adverse event monitoring for tyrosine kinase inhibitors, but might also serve as a biomarker for dose titrations. This study explored the impact of various sources of within-individual variation on blood pressure readings to improve measurement practices and evaluated the utility for individual- and population-level dose selection. A pharmacokinetic-pharmacodynamic modeling framework was created to describe circadian blood pressure changes, inter- and intra-day variability, changes from dipper to non-dipper profiles, and the relationship between drug exposure and blood pressure changes over time. The framework was used to quantitatively evaluate the influence of physiological and pharmacological aspects on blood pressure measurements, as well as to compare measurement techniques, including office-based, home-based, and ambulatory 24-h blood pressure readings. Circadian changes, as well as random intra-day and inter-day variability, were found to be the largest sources of within-individual variation in blood pressure. Office-based and ambulatory 24-h measurements gave rise to potential bias (>5 mmHg), which was mitigated by model-based estimations. Our findings suggest that 5-8 consecutive, home-based, measurements taken at a consistent time around noon, or alternatively within a limited time frame (e.g., 8.00 a.m. to 12.00 p.m. or 12.00 p.m. to 5.00 p.m.), will give rise to the most consistent blood pressure estimates. Blood pressure measurements likely do not represent a sufficiently accurate method for individual-level dose selection, but may be valuable for population-level dose identification. A user-friendly tool has been made available to allow for interactive blood pressure simulations and estimations for the investigated scenarios.

Chronic Kidney Disease and Left Ventricular Hypertrophy. Potent Modifiers of the Prognostic Impact of Circadian Blood Pressure Changes.

It is unclear whether the prognostic value of blood pressure (BP) changes from day to night is modified by concomitant risk factors and organ damage. We studied 3247 clinically hypertensive patients who underwent off-therapy 24-hour ambulatory BP monitoring during their initial diagnostic work-up. Over a mean 9.9-year follow-up, 292 patients developed a first primary outcome event (composite of nonfatal myocardial infarction, nonfatal stroke, cardiovascular death, hospitalization for heart failure) and 281 died. The day-night BP changes were analyzed as night-to-day systolic BP ratio and included in semiparametric Cox models. After allowance for age, sex, diabetes, cigarette smoking, low-density lipoprotein cholesterol, serum uric acid and average 24-hour systolic BP, the night-to-day systolic BP ratio maintained an independent association with outcome (hazard ratio, 1.17 [1.01-1.35]; P=0.041). When 2 markers of organ damage, chronic kidney disease and left ventricular hypertrophy, were added to the model, the night-to-day systolic BP ratio failed to maintain an independent association with outcome (hazard ratio, 1.19 [0.97-1.31]). The Akaike Information Criterion and the Schwarz-Bayes Information Criterion showed that, after allowance for other covariables, the night-to-day systolic BP ratio: (1) provided less information when compared with chronic kidney disease and left ventricular hypertrophy and (2) did not improve information provided by chronic kidney disease and left ventricular hypertrophy. Results were comparable on all-cause death as well as using categories of the night-day systolic BP ratio (extreme dippers, dippers, nondippers, reverse dippers). Chronic kidney disease and left ventricular hypertrophy are potent modifiers of the prognostic value of the circadian BP changes.

Features of the daily blood pressure in children with diabetes depending on the duration of the disease

Background. The presence of hypertension, which in diabetic patients occurs 2 times more often than in the general population, increases the risk of cardiovascular complications. The main tool for the diagnosis of hypertension in children is ambulatory blood pressure monitoring (ABPM) due to the fact that a number of ABPM parameters may act as predictors of the deve­lopment of cardiovascular events. The purpose was to establish the features of the daily blood pressure in children with diabetes depending on the duration of the disease. Materials and methods. The paper investigated the features of the daily arterial pressure in 53 children (mean age 14.79 ± 0.25 years) with diabetes mellitus, according to the ABPM data. Depending on the duration of the disease, there were 3 groups: group 1 — 11 children with disease duration of up to 1 year, group 2 — 19 persons with disease duration of 1–5 years, and group 3 — 23 patients with disease duration of more than 5 years. The control group consisted of 20 children, representative by the age and sex, who had no disorders of carbohydrate metabolism and intercurrent diseases. Results. In children with diabetes, with an increase in the duration of the disease, there was an elevation in the blood pressure, its variability and the index of hypertension. Hypertension occurred in 21.0 % of patients with duration of diabetes from 1 to 5 years and in 43.5 % of persons with disease duration of more than 5 years. Identified changes occurred on the background of the circadian blood pressure changes, which took place during the first year of the disease and observed in 51.0–54.5 % of patients. Among the pathological profiles of nocturnal blood pressure reduction in patients with diabetes mellitus, the non-dipper type prevailed (43.5–47.4 %). Conclusions. The majority of patients with diabetes mellitus experienced changes in blood pressure, the first signs of which were registered in the first year of the disease and progressed with an increase of its the duration. The findings suggest that children with diabetes, regardless of the duration of the disease, should be classified as high risk for developing hypertension.

Circadian blood pressure profile and blood pressure changes following oral appliance therapy for obstructive sleep apnoea.

Oral appliance therapy for obstructive sleep apnoea (OSA) reduces blood pressure (BP) but there is little information on relationship to circadian BP pattern (nocturnal BP dipping or non-dipping). The aims of this study were to determine whether nocturnal dipping pattern influences BP changes following oral appliance therapy, and to determine the effect of oral appliance therapy on circadian BP pattern. Participants in two randomized trials of oral appliance therapy (1-2 months) with 24-h ambulatory BP monitoring (ABPM) data were included (N = 152). Nocturnal BP Dippers (nocturnal/diurnal SBP ratio <0.9) and non-dippers were compared for BP changes following oral appliance therapy and the effect of oral appliance therapy on nocturnal BP dipping was assessed. Of 152 participants, 64.5% were dippers. Dippers were on average younger and less likely to be hypertensive (42 vs. 82.7%, P < 0.001). Nondippers showed greater reduction in nocturnal BP measures, related to higher BP measures at baseline. There was no difference in the relationship between treatment effectiveness and BP changes between groups. Oral appliance therapy converted only 23% of baseline non-dippers to a nocturnal dipping profile. Baseline circadian BP profile influenced the BP response to oral appliance therapy, largely because of higher baseline BP in the non-dipper subgroup. Oral appliance therapy did not convert OSA patients to a more favourable circadian BP profile. Further work is required to understand the effect of oral appliance therapy on circadian BP profile and of the individuals who will receive cardiovascular benefit from oral appliance therapy.

Haemodynamic changes and peripheral vascular characteristics associated with pathophysiological alterations in Preeclampsia patients at the University Teaching Hospital, Lusaka, Zambia

Background: The circadian blood pressure changes in pregnancy are poorly documented though the severity of hypertensive disorders especially in pregnancy is said to be better detected by 24hour blood pressure monitoring. The contribution of peripheral vascular variations to these alterations is yet to be elicited. The association of these changes to the renal pathological dysfunction is also not fully understood.Materials and method: Ambulatory blood pressure measurements and kidney function tests (i.e. creatinine, protein, sodium and uric acid) were done in patients admitted to UTH for hypertension in second and third trimesters of pregnancy. The Complior was used to determine the pulse waveform, pulse wave velocity (PWV) and augmentation index (Aix) as surrogate parameters for peripheral vascular compliance.Results: Twenty-six (26) women, between 22-42 years old and 24-36 gestational weeks, participated in this study. The majority of our population were either non- or reverse dippers (91.6%). The type A pulse waveform was dominant in all three groups indicating endothelial dysfunction. Dippers had a higher creatinine concentration in both urine and serum and uric acid in serum than non-dippers (7.051mmol/24hrs; 108.703ìmol/L;0.507mmol/L; respectively p&lt;0.0001). The observed association of diurnal variations inhemodynamic parameters and dipping status indicates significant vascular pathology that may herald these individuals' increased risk of cardiovascular complications. The dominance of the type A pulse waveform in this population is indicative of significant endothelial dysfunction.Conclusion: The association seen between elevated blood pressure readings and proteinuria indicates a possible common pathophysiological process that leads to increased porosity at the glomeruli.

Prognostic value of average real variability of systolic blood pressure in elderly treated hypertensive patients.

The independent prognostic significance of ambulatory blood pressure variability in the elderly is incompletely clear. We investigated the prognostic value of average real variability of 24-hour blood pressure in elderly treated hypertensive patients. The occurrence of a combined end-point including stroke, coronary events, heart failure requiring hospitalization and peripheral revascularization was evaluated in 757 elderly treated hypertensive patients. According to tertiles of average real variability of 24-hour systolic blood pressure patients were classified as having low (≤8.66 mmHg; n = 252), medium (8.67-10.05 mmHg; n = 252) or high (>10.05 mmHg; n = 253) average real variability. During the follow-up (6.9 ± 3.4 years, range 0.4-12.9 years), 195 events occurred. The event rate of the population was 3.74 per 100 patient-years. After adjustment for age, sex, previous events, diabetes, estimated glomerular filtration rate, left ventricular hypertrophy, left atrial enlargement, asymptomatic left ventricular systolic dysfunction at baseline, 24-hour systolic blood pressure, non-dipping and dipping with high morning surge of blood pressure, patients with high average real variability were at higher cardiovascular risk than those with low average real variability (hazard ratio 1.64, 95% confidence interval 1.12-2.40). In elderly treated hypertensive patients, high average real variability of 24-hour systolic blood pressure is associated with higher cardiovascular risk independently of other risk markers, average 24-hour systolic blood pressure and circadian blood pressure changes.

Upotreba tapping zadataka kao indikatora cirkadijurnih promjena stanja organizma

Seven trained subjects (20—23 years old) took part in an experiment on circadian changes in body temperature, heart ratte and blood pressure. The values of these variables were taken every hour during 24 hours. Immediately after that the subjects were asked to do a tapping task (regular tapping on a micro-switch) while resting and during the multiplication of 3-digital numbers with 2 and 3-digital numbers with 7. The time intervals between successive tappings were recorded in m/s via a computer on the disquettes. Various variability indeices of the tapping task intervals showed high correlations amongst themselves, while the correlations were generally lower amongst the parameters of the psychological variables, tapping parameters and mental arithmetics. Furthermore, the taping PML-index wasn’t found as a good indicator of a mental load under the conditions of the multiplication of the 3-digital numbers with 2 and 7, while at the same time significant correlations were obtained between some tapping task parameters and mental arithmetic. It seems however, that some kind of other analyses might be more promising.

Circadian blood pressure changes and cardiovascular risk in elderly-treated hypertensive patients.

The independent prognostic significance of circadian blood pressure (BP) changes is unclear. We investigated the association between circadian BP changes and cardiovascular risk among elderly-treated hypertensive patients. The occurrence of a composite end point (that is, stroke, coronary events, heart failure and peripheral revascularization) was evaluated among 1191 elderly-treated hypertensive patients (age range 60-90 years). According to the nighttime change and the morning surge (MS) of systolic BP, subjects were divided into groups of dippers with a normal or high MS (DNMS and DHMS, respectively), non-dippers (ND), reverse dippers (RD) and extreme dippers with a normal or high MS (EDNMS and EDHMS, respectively). During the follow-up (9.1±4.9 years, range 0.4-20 years), 392 events occurred. The event rate was 3.63 per 100 patient-years. After adjustment for various covariates, including 24-h BP, the DHMS (hazard ratio (HR) 1.49, 95% confidence interval (CI) 1.02-2.16, P=0.04), ND (HR 1.71, 95% CI 1.28-2.27, P=0.0001), RD (HR 2.05, 95% CI 1.44-2.93, P=0.0001) and EDHMS (HR 3.40, 95% CI 1.96-5.90, P=0.001) were at higher cardiovascular risk than the DNMS. The population attributable risk was 0.6, 7.1, 7.3 and 1.4% for the DHMS, ND, RD and EDHMS, respectively. In elderly-treated hypertensive patients, circadian BP changes were independently associated with increased cardiovascular risk. At the patient level, the highest risk was observed among the EDHMS, followed by the RD, ND and DHMS. At the population level, the highest risk was observed among the RD, followed by the ND, EDHMS and DHMS.

Circadian changes in blood pressure in the brachial artery and the aorta assessed by simultaneous monitoringin untreated hypertension

Objective . To study and compare the daily changes of parameters of central pulse wave (PW) with the traditional indicators of 24‑hour ambulatory blood pressure monitoring (ABPM) on the brachial artery (BA) depending on daily profile in different age groups. Design and methods . Successful ABPM of brachial and central BP (&gt; 85 % valid readings) was performed by oscillometric BPLab VASOTENS system (“Petr Telegin”, Nizhniy Novgorod, Russia) in 84 untreated hypertensive subjects (mean age 55,8 ± 9,6 years, male 36,9 %, clinical BP 152,6 ± 9,2 / 94,8 ± 8,2 mm Hg). The device allows to derive aortic BP and augmentation index (AIx) from brachial PW. Gender differences of central BP and AIx were evaluated in different age groups: &lt; 55 (14 men, 23 women), 55–60 (7 men, 16 women), 61–70 years (10 men, 14 women). Differences were considered significant at p &lt; 0,05. Results. Nighttime central BP was disproportionately higher than daytime values, proven by a smaller difference between BP in BA and the aorta at night compared to daytime parameters. AIx@75 was higher at night than during day. The differences between systolic BP (SBP) and BP in BA and the aorta was 10,4 ± 2,2 and 11,4 ± 1,0 mmHg in daytime and lower at night — 8,1 ± 2,0 and 9,0 ± 1,8 mmHg. The number of non-dippers and night-pickers according to aortic SBP values was greater than according to SBP assessed in BA. Men had slightly higher levels of brachial and aortic SBP than women. More profound nocturnal decline of brachial and aortic SBP was found in in women than in men. Despite comparable heart rate, AIx@75 was higher in women at all time periods, however, nocturnal increase in AIx@75 was significantly more evident in men. Conclusions. Central BP was disproportionately higher at nighttime than during the day, proven by a smaller difference between BP in BA and the aorta at night than during the day. AIx and its diurnal variation are characterized by gender-associated differences across all age group and are dependent on SBP daily profile. This finding should be considered when interpreting the results 24‑hour monitoring of central BP and requires further investigation of its prognostic value.

Circadian Blood Pressure Rhythm Is Changed by Improvement in Hypoalbuminemia and Massive Proteinuria in Patients with Minimal Change Nephrotic Syndrome

Background: Proteinuria and nighttime blood pressure (BP) elevation are notable risk markers of chronic kidney disease and correlate closely with each other. However, daily urinary protein excretion (UPE) always fluctuates. In patients with minimal change nephrotic syndrome (MCNS), serum albumin concentrations (SAC) decrease but fluctuate less than UPE. We evaluated whether SAC is a reliable marker for proteinuria, and compared the relations among circadian BP changes, SAC, and UPE. Methods: In patients with MCNS (12 men and 11 women, 43 ± 18 years), blood and spot urine samples were collected on three consecutive days before treatment, and 24-hour BP was also measured on the three days. Then, an intervention study was conducted in the patients to examine circadian BP changes induced by treatment. Sleeping/waking BP ratio was analyzed as an indicator of circadian BP rhythm. Results: In the three-day measurements before treatment, mean coefficient of variation, an index of dispersion of data, for SAC was 7.4 ± 7.4%, which was markedly lower (p < 0.01) than 35.7 ± 15.4% for UPE. SAC correlated inversely with sleeping/waking systolic and diastolic BP ratios on all three days, whereas UPE did not correlate significantly with sleeping/waking diastolic BP ratio on day 3. Sleeping/waking systolic and diastolic BP ratios were 96 ± 5 and 95 ± 6%, and were higher (p < 0.05) than in healthy subjects (89 ± 8 and 88 ± 10%). Treatment improved hyperproteinuria and hypoalbuminemia, and was accompanied by decreases (p < 0.05) in sleeping and waking systolic/diastolic BP ratio to 91 ± 8 and 89 ± 9%. Conclusion: These findings suggest that reduced SAC in patients with proteinuria is associated with disrupted circadian BP rhythm.

Impact of Gender on the Association of Epicardial Fat Thickness, Obesity, and Circadian Blood Pressure Pattern in Hypertensive Patients.

This study aimed to investigate the effects of gender on the association between epicardial fat thickness (EFT) and circadian blood pressure (BP) changes in patients with recently diagnosed essential hypertension (EH). A total of 441 patients with EH (male/female: 236/205, mean age: 50.7 ± 13.8) and 83 control patients underwent 24-hour ambulatory BP monitoring and echocardiography. Obese EH patients had higher circadian BP profile with BP variability, wall thickness, and left ventricular mass than nonobese EH patients and controls (all p's <0.05) without gender differences. EFT was higher in female than in male patients (7.0 ± 2.5 versus 5.9 ± 2.2 mm, p < 0.001) and higher in the obese female EH group (7.5 ± 2.6 mm) than in the control (6.4 ± 2.8 mm) or nonobese EH group (6.7 ± 2.8 mm) among women, whereas EFT did not vary among males (5.9 ± 1.9 versus 6.0 ± 2.7 versus 5.9 ± 2.4 mm, p = 0.937). Multivariate logistic regression analysis demonstrated that the 24-hour mean BP variability was associated with SBP (p = 0.018) and EFT (p = 0.016) in female patients, but not in male patients. The relationships among circadian BP variability, obesity, and EFT were affected by gender in different manners. EFT may be a more valuable parameter in the evaluation of BP severity and obesity in women than in men.

Effects of exercise timing on sleep architecture and nocturnal blood pressure in prehypertensives.

BackgroundDuring nocturnal sleep, blood pressure (BP) “dips” compared to diurnal BP, reducing stress on the cardiovascular system. Both the hypotensive response elicited by acute aerobic exercise and sleep quality can impact this dipping response.PurposeThe purpose of this study was to investigate the effects of aerobic exercise timing on circadian BP changes and sleep architecture.Materials and methodsTwenty prehypertensive subjects completed the study. During four test sessions, participants first completed a graded exercise test to exhaustion and then performed 30 minutes of treadmill exercise at 7 am (7A), 1 pm (1P), and 7 pm (7P) in a random, counterbalanced order at 65% of the heart rate obtained at peak oxygen uptake. An ambulatory cuff was used to monitor BP responses during 24 hours following exercise, and an ambulatory sleep-monitoring headband was worn during sleep following each session.ResultsAerobic exercise at 7A invoked a greater dip in nocturnal systolic BP than exercise at 1P or 7P, although the greatest dip in nocturnal diastolic BP occurred following 7P. Compared to 1P, 7A also invoked greater time spent in deep sleep.ConclusionThese data indicate that early morning may be the most beneficial time to engage in aerobic exercise to enhance nocturnal BP changes and quality of sleep.

Circadian Blood Pressure (CBP) Alterations and Other Etiological Risk Factors in Patients with Lacunar Infarction

PP-034 Although the occurrence of lacunar infarction is closely related to arterial hypertension. The possible pathogenetic role of circadian blood pressure changes is controversial. This study was designed to evaluate the relationship between circadian blood pressure changes and occurrence of

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. (Author correspondence: neuronet@catholic.ac.kr)

Hypoalbuminemia and Hyperalbuminuria as Major Factors Regulating Circadian Blood Pressure Rhythm in Normal Subjects and Non-diabetic Patients with Early Stages of Chronic Kidney Disease

Study background: Albuminuria and nighttime blood pressure (BP) elevation are notable risk markers of chronic kidney disease (CKD). In non-diabetic patients with albuminuria, the effect of albuminuria on nocturnal BP and other risk factors that may disrupt circadian BP rhythm remain unclear. The aim of this study was to evaluate the relationship among albuminuria, serum albumin level and 24-hour BP rhythm in non-diabetic subjects. Methods: This prospective study enrolled 778 subjects (aged 20-80 years, estimated glomerular filtration rate ≥ 60 mL/min/1.73 m2). Main outcome measure was sleeping/waking mean BP (MBP) ratio as an indicator of circadian BP rhythm. First, a cross-sectional study was performed in all individuals showing no proteinuria. Second, a study was done in subjects never treated for hypertension (hypertensive-naive) stratified by urinary albumin excretion. Third, an intervention study was conducted in patients with massive albuminuria and hypoalbuminemia to examine circadian BP changes induced by treatment. Results: In 441 subjects without proteinuria, multivariate regression analyses identified serum albumin, cholesterol level and circadian sympathovagal rhythm as independent predictors of sleeping/waking MBP ratio. Among hypertensivenaive non-diabetic subjects (n=231), sleeping/waking MBP ratio increased with increasing albuminuria and decreasing serum albumin. Of 37 non-diabetic nephrotic patients who underwent treatment, 25 with serum albumin level increased to >3 g/dL showed a significant decrease (P=0.026) in sleeping/waking MBP ratio after treatment, whereas 13 with urinary albumin/creatinine lowered to <300 mg/g showed no significant difference (P=0.191). Conclusions: This study identified low serum albumin as an independent predictor of loss of nocturnal BP decline, which was also associated with massive albuminuria. Furthermore, sleeping/waking MBP ratio was improved after hyperalbuminuria and hypoalbuminemia were reversed by treatment. These findings suggest that low serum albumin level and massive albuminuria are risk markers of disrupted circadian BP rhythm in non-diabetic early stage CKD.

Coronary Risk Factors and Ambulatory Blood Pressure and Heart Rate in Asian Indians

Wang and co-workers reported on ethnic differences in ambulatory blood pressure (ABP) in African Americans compared to people of European origin (1). Data on ABP and heart rate (HR) on American Indians and Asian Indians could have made this study even more interesting (2). Details on diet and lifestyle factors also appear to be important for mapping circadian changes in blood pressure (BP) in populations studied by the BIOCOS group (3). Circadian changes in BP are synchronized by the daily routine via plasma concentrations of neurotransmitters, released by the pineal, pituitary and adrenal cortices, coordinated by clock genes situated in the brain's suprachiasmatic nucleus (2), and at the cellular level (4, 5). Many studies focusing on this issue have relied mostly on single measurements of BP and HR rather than on week-long profiles obtained with an ABPM, interpreted with a view of their time structures (chronomes) (3). It is now accepted that ABPM is superior to clinical spotchecks in terms of diagnosis and prognosis (6). Our study involved 209 subjects (142 men and 67 women) 42.4 ± 18.0 years of age living in Moradabad, India. Anticipated relationships were found. Namely, the MESOR of SBP, DBP and HR increased with age (SBP: r= 0.260, P<0.001; DBP: r=0.269, P<0.001; HR: r=0.242; P<0.005), as well as with BMI (SBP: r=0.232, P<0.005; DBP: r=0.257, P<0.001). The MESOR of HR also decreased with increased activity (F=5.558, P=0.001). The MESOR of SBP also decreased slightly with increased activity, yet the relationship is not statistically significant. Additional relations were uncovered. The SD of DBP increased as a function of BMI (r=0.248, P=0.002), whereas

Epicardial Fat Thickness Is Associated with Non-Dipper Blood Pressure Pattern in Patients with Essential Hypertension

Objective. Epicardial fat tissue reflects visceral adiposity and is a suggested cardiometabolic risk factor. Patients with abdominal obesity have an increased prevalence of the non-dipper blood pressure (BP) pattern, but it is unclear whether the same is true of patients with increased epicardial fat thickness (EFT). The association between EFT and circadian BP changes in patients with recently diagnosed essential hypertension was examined. Methods. Sixty hypertensive patients underwent echocardiography, treadmill stress testing, and 24 hours of ambulatory BP monitoring. Epicardial fat thickness and left ventricular mass (LVM) index were measured by using transthoracic echocardiography. The patients were categorized into two groups according to their BP pattern (group 1, non-dippers; group 2, dippers). Results. The mean EFT and LVM of patients in group 1 (n = 24) (EFT, 7.6 ± 2.1 mm; LVM, 130 ± 31.2 g/m2) were significantly greater than those of group 2 (n = 36) (EFT, 5.5 ± 1.2 mm, P = .0001; LVM, 107 ± 23.7 g/m2, P = .002). The average systolic BP over 24 hours (BPs 24) and average diastolic BP over 24 hours (BPd 24) of group 1 (BPs 24, 151.1 ± 17.6 mm Hg; BPd 24, 94.1 ± 16.5 mm Hg) were significantly higher than those of group 2 (BPs 24, 136.7 ± 11.9 mm Hg, P = .0001; BPd 24, 84.6 ± 10.6 mm Hg; P = .008). Multivariate backward logistic regression analysis demonstrated that the non-dipper BP pattern was associated with EFT (standardized β coefficient = 0.87, P = .005) and LVM (standardized β coefficient = 0.43, P = .016). An EFT ≥ 7 mm was associated with the non-dipper BP pattern with 44% sensitivity and 94% specificity (receiver operating characteristic area under curve of 0.72, 95% CI [0.59–0.83], P = .0007). Conclusions. Epicardial fat thickness was above average in newly diagnosed, untreated hypertensive patients with non-dipper BP pattern. The echocardiographic measurement of EFT may be used to indicate increased risk of hypertension-related adverse cardiovascular events.

Circadian changes in autonomic function in conscious rats with heart failure: Effects of amiodarone on sympathetic surge

Cardiovascular events are characterized by circadian periodicity with a peak prevalence during the awakening period, which suggests a morning surge in sympathetic activity. We developed an experimental system to determine circadian changes in heart rate (HR), blood pressure (BP), locomotor activity (Loc), respiratory rate and autonomic function in conscious, unrestrained rats. The effects of amiodarone on circadian variation of these variables were determined in rats with myocardial infarction and subsequent congestive heart failure (CHF). We continuously recorded BP, HR and Loc for 24 h in rats with CHF ( n = 16) or after a sham operation (Sham; n = 7). To determine circadian changes in sympathovagal balance, digitized BP and HR data throughout 24 h were analyzed based on maximum entropy. The study was repeated after 3 weeks of oral amiodarone (50 mg/kg/day) or saline administration. Baseline HR, mean BP, and Loc were higher in the dark period than in the light period (all p < 0.05) in both CHF and Sham rats, which is consistent with the circadian periodicity of nocturnal animals. Low-frequency components of diastolic BP variability (LFdp), an index of sympathetic tone, were significantly higher during the awakening period (16:00–20:00) than during the sleeping period (08:00–14:00), a finding analogous to the sympathetic morning surge in men. Amiodarone suppressed this transient increase in LFdp power during the awakening period. Our experimental system could detect sympathetic surge in conscious rats. Amiodarone suppressed the sympathetic surge, which could explain, at least in part, beneficial effects of amiodarone in patients with CHF.