Nighttime Decrease Research Articles

The clock-associated LUX ARRHYTHMO regulates high-affinity nitrate transport in Arabidopsis roots.

The circadian clock organizes physiological processes in plants to occur at specific times of the day, optimizing efficient use of resources. Nitrate is a crucial inorganic nitrogen source for agricultural systems to sustain crop productivity. However, because nitrate fertilization has a negative impact on the environment, it is important to carefully manage nitrate levels. Understanding crop biological rhythms can lead to more ecologically friendly agricultural practices. Gating responses through the circadian clock could be a strategy to enhance root nitrate uptake and to limit nitrate runoff. In Arabidopsis, the NITRATE TRANSPORTER 2.1 (NRT2.1) gene encodes a key component of the high-affinity nitrate transporter system. Our study reveals that NRT2.1 exhibits a rhythmic expression pattern, with daytime increases and nighttime decreases. The NRT2.1 promoter activity remains rhythmic under constant light, indicating a circadian regulation. The clock-associated transcription factor LUX ARRHYTHMO (LUX) binds to the NRT2.1 promoter in vivo. Loss-of-function of LUX leads to increased NRT2.1 transcript levels and root nitrate uptake at dusk. This supports LUX acting as a transcriptional repressor and modulating NRT2.1 expression in a time-dependent manner. Furthermore, applying nitrate at different times of the day results in varying magnitudes of the transcriptional response in nitrate-regulated genes. We also demonstrate that a defect in the high-affinity nitrate transport system feeds back to the central oscillator by modifying the LUX promoter activity. In conclusion, this study uncovers a molecular pathway connecting the root nitrate uptake and circadian clock, with potential agro-chronobiological applications.

Passive Design Strategy in Vernacular House of Samin, Indonesia

Vernacular architecture embodies passive design principles and strategies to create comfortable dwellings. This study investigates the impact of passive design strategies on temperature comfort in Samin vernacular houses. Visual observation is employed to assess the suitability of house elements based on passive design criteria. At the same time, field measurements are conducted to evaluate comfortable temperature conditions using data loggers over one month. The research focuses on the Original Samin house and the New Samin house situated in Klopoduwur Village, Blora Regency, Central Java, Indonesia. The visual observation reveals that the roof volume, slope, and thin walls with low conductivity in both Samin houses align with passive design principles. The New Samin house also incorporates other passive design strategies, including an east-west building orientation with the long side perpendicular to the wind direction, an open-plan room layout, and varying floor heights. The temperature comfort performance in both houses falls within the neutral temperature range during 16 hours. The New Samin house exhibits the largest daytime air temperature decrease at 5.5°C, while the Original Samin house experiences the largest nighttime decrease at 0.7°C. The evolution of passive designs in Samin vernacular houses encompasses considerations such as building proportion and width, terrace width, positioning and size of window openings, vegetation, and shading elements.

#2049 Prognosis of decreased renal function in patients with arterial hypertension

Abstract Background and Aims Chronic kidney disease and hypertension are closely related in cause and effect. As the glomerular filtration rate decreases, the frequency and severity of arterial hypertension increases. In addition, the risk of morbidity and mortality from cardiovascular diseases increases significantly with comorbidity of arterial hypertension and chronic kidney disease. The purpose of this study was to identify predictors of a decrease in GFR below 60 ml/min in patients with arterial hypertension. Method The cross-sectional study included 43 patients with arterial hypertension (average age 56.7 (10.6) years). Exclusion criteria were age over 80 years, primary kidney disease, diabetes mellitus, cancer, heart failure, stage III arterial hypertension. All patients underwent determination of cystatin C in the blood, the composition of the body was studied using the bioimpedance method and 24-hour blood pressure monitoring. To identify predictors of kidney damage, we used regression analysis with ROC curve estimation using MedCalc software. Results The optimal value (cut-off point) of the content of total adipose tissue, which allows the most accurate prediction of a decrease in GFR < 60 ml/min in patients with hypertension, was 26.1% (sensitivity −100%, specificity—77.8%), and the content of total muscle tissue—35.9% (sensitivity −100%, specificity—44.4%). The optimal value (cut-off point) of cystatin C was 1.13 (sensitivity −100%, specificity—53.9%), AUC—0.73 (0.46; 0.92). At the same time, when this predictor was included once in multiple logistic regression, the statistical significance decreased (p = 0.5). Among individual predictors of decreased renal function, indicators of 24-hour blood pressure monitoring were studied. The optimal value (cut-off point) of the ambulatory arterial stiffness index, which allows the most accurate prediction of a decrease in GFR < 60 ml/min in patients with arterial hypertension, was 0.36 (sensitivity −100%, specificity—71.4%), an indicator of an increase in the rate of increase in diastolic blood pressure. blood pressure—0.27%, AUC 0.74 (0.48; 0.91)) and the rate of increase in nighttime decrease in systolic blood pressure—8.1%, AUC 0.71 (0.47; 0.89). Conclusion Increase in total adipose tissue > 26.1%, decrease in total lean tissue <35.9%, increase in ambulatory arterial stiffness index >0.36, increase in rate of increase in diastolic blood pressure >0.27%, and increased nocturnal decrease in systolic blood pressure > 8.1% were identified as significant predictors of a decrease in GFR below 60 ml/min in hypertension.

THE INFLUENCE OF EXTREME DIPPING PRESSURE ON LEFT VENTRICULAR HYPERTROPHY IN GENERAL POPULATION

Objective: Extreme dipping pressure, characterized by a nighttime decrease of over 20% compared to daytime levels, lacks consensus regarding its influence on cardiac structure and function. Particularly in the general population, there's limited research on this common blood pressure pattern. This study aims to investigate the relationship between extreme dipping pressure and cardiac structure and function in a general population. Design and method: We conducted 24-hour ambulatory blood pressure monitoring in 673 individuals without hypertension to assess blood pressure patterns. We analyzed the association between extreme dipping pressure and left cardiac structure, left ventricular hypertrophy (LVH), and left ventricular diastolic function. Results: Using a criterion of a nighttime decrease of over 20% in systolic and/or diastolic blood pressure, extreme dipping pressure was observed in 15.8% (107/673) of the general population. LVH prevalence in this study was 18.9% (127/673), with extreme dipping, non-dipping, and dipping patterns observed in 12.6%, 39.4%, and 48.0%, respectively, in the LVH group. In the non-LVH group, these patterns were observed in 16.5%, 47.8%, and 35.7%, respectively. A significant difference in distribution between different blood pressure patterns existed between the LVH and non-LVH groups (p=0.19). Univariate analysis indicated that, compared to the non-dipping pattern, extreme dipping was a protective factor for LVH occurrence (p=0.045, OR 0.173, 95%CI 0.031-0.959). Even after adjusting for factors such as gender, age, BMI, left ventricular size, interventricular septum thickness, left ventricular posterior wall thickness, and overall blood pressure, extreme dipping remained a protective factor for LVH occurrence (p=0.019, OR 0.187, 95%CI 0.046-0.756). Conclusions: Our study indicates that extreme dipping pressure is relatively common in the general population and is closely associated with LVH occurrence. In the general population, extreme dipping independently reduces the occurrence of LVH.

Diel variation of seawater volatile organic compounds, DMSP-related compounds, and microbial plankton inside and outside a tropical coral reef ecosystem

Biogenic volatile organic compounds (VOCs) play key roles in coral reef ecosystems, where, together with dimethylated sulfur compounds, they are indicators of ecosystem health and are used as defense strategies and infochemicals. Assessment and prediction of the exchange rates of VOCs between the oceans and atmosphere, with implications for atmospheric reactivity and climate, are hampered by poor knowledge of the regulating processes and their temporal variability, including diel cycles. Here, we measured the variation over 36h of the concentrations of DMSPCs (dimethylsulfoniopropionate (DMSP)-related compounds, namely DMSP, dimethylsulfoxide, acrylate, dimethylsulfide, and methanethiol as dimethyl disulfide) and VOCs (COS, CS2, isoprene, the iodomethanes CH3I and CH2ClI, and the bromomethanes CHBr3 and CH2Br2), in surface waters inside the shallow, northern coral-reef lagoon of Mo’orea (French Polynesia) and 4 km offshore, in the tropical open ocean. Comparisons with concurrent measurements of sea surface temperature, solar radiation, biogeochemical variables (nutrients, organic matter), and the abundances and taxonomic affiliations of microbial plankton were conducted with the aim to explain interconnections between DMSPCs, VOCs, and their environment across diel cycles. In open ocean waters, deeper surface mixing and low nutrient levels resulted in low phytoplankton biomass and bacterial activity. Consequently, the diel patterns of VOCs were more dependent on photochemical reactions, with daytime increases for several compounds including dissolved dimethylsulfoxide, COS, CS2, CH3I, and CH2ClI. A eukaryotic phytoplankton assemblage dominated by dinoflagellates and haptophytes provided higher cell-associated DMSP concentrations, yet the occurrence of DMSP degradation products (dimethylsulfide, dimethyl disulfide) was limited by photochemical loss. Conversely, in the shallow back reef lagoon the proximity of seafloor sediments, corals and abundant seaweeds resulted in higher nutrient levels, more freshly-produced organic matter, higher bacterial activity, and larger algal populations of Mamiellales, diatoms and Cryptomonadales. Consequently, DMSP and dimethylsulfoxide concentrations were lower but those of most VOCs were higher. A combination of photobiological and photochemical processes yielded sunny-daytime increases and nighttime decreases of dimethylsulfide, dimethyl disulfide, COS, isoprene, iodomethanes and bromomethanes. Our results illustrate the important role of solar radiation in DMSPC and VOC cycling, and are relevant for the design of sampling strategies that seek representative and comparable measurements of these compounds.

Features of arterial pressure dynamics according to results of blood pressure monitoring in elderly patients

All over the world, special attention is paid to cardiovascular diseases in patients. According to epidemiological studies, a large contribution to mortality from them is high blood pressure, effective normalization of blood pressure will lead to an increase in life expectancy. The purpose of the study: to study the features of the daily blood pressure profile in elderly patients with hypertension. It was revealed that hypertension in elderly patients is more severe and has significantly higher rates of rise in systolic and diastolic pressure during the day and night hours, high variability, and insufficient (non-dipper) night-time decrease in blood pressure.Therefore, sick groups have a high risk of developing target organ damage, which is a predictor of the development of cardiovascular complications.

Показатели суточного мониторинга артериального давления у лиц старческого возраста c хронической сердечной недостаточностью в зависимости от жесткости сосудов

INTRODUCTION: Measurement of arterial pressure (AP) is a standard method for assessing the risk of developing cardiovascular diseases. Analysis of systolic and diastolic pressure, as well as their ratio, can help determine the risk of developing cardiovascular diseases. One of the ways to diagnose elevatedarterial pressure is daily monitoring of arterial pressure (DMAP). An increase in AP in the elderly is usually associated with an increase in the stiffness of the vascular walls. This leads to an increase in systolic arterial pressure (SAP) and pulse pressure (PP), as well as a decrease in diastolic arterial pressure (DAP). Elevated arterial pressure enhances the load on the heart and can lead to its pathological alterations. A decrease in DAP impairs the blood supply to the heart, which can cause ischemia and fibrosis; the result isdevelopment of diastolic dysfunction, which is the main cause of chronic heart failure (CHF). Currently, a promising way to determine the arterial stiffness is measurement of a cardio-ankle vascular index.The prognostic and diagnostic value of this parameter has been confirmed by numerous studies. It is important to study the parameters of the daily AP profile and arterial stiffness in older patients with CHF. This permits to identify malignant forms of elevated blood pressure, which can lead to cardiovascular complications. AIM: To study the characteristics of the parameters of the daily arterial pressure profile in elderly patients with CHF, depending on the vascular stiffness determined by volume sphygmography. MATERIALS AND METHODS: One hundred and twenty elderly patients with CHF undergoing treatment in a cardiology hospital were examined. By the method of volume sphygmography, the patients were divided into groups with ‘vessels of normal stiffness’ (group 1) and ‘stiff vessels’ (group 2), with subsequentDMAP. A statistical analysis of the parameters of the daily AP profile in the groups was performed. RESULTS: In patients of group 1, both daytime and nighttime SAP, DAP and PP, were significantly higher than in patients of group 2. Besides, in group 1, there was a nighttime decrease in SAP and DAP, while the morning rise of SAP was statistically higher in group 2, and no differences were recorded between the groups in the morning rise of DAP. When assessing the ankle-brachial index in patients of group 2, daytime and nighttime SAP and DAP were statistically higher. In group 1 (with probable peripheral atherosclerosis), PP was higher both during the day and at night. The nocturnal decrease in SAP was statistically higher in group 2, while the nocturnal decrease in DAP prevailed in group 1. The morning rise of SAP and DAP was higher in group 1. CONCLUSION: The DMAP data may indicate to some extent the severity of hypertension in patients with CHF, and this probably depends on the ‘stiffness of the vessels’. In elderly patients with CHF with ‘normal stiffness’ of vessels, the parameters of the daily arterial pressure profile were higher than in patients with ‘stiff vessels’. However, the daily range of parameters of the daily arterial pressure profile was greater in the group of patients with ‘stiff vessels’ (group 2).

Features of Allostatic Load in Patients with Essential Hypertension without Metabolic Syndrome Depending on the Nature of Nighttime Decreases in Blood Pressure

Changes in the activity of the renin–angiotensin–aldosterone system are responsible for a stable shift in the regulation of the cardiovascular system in essential hypertension (EH). They can be characterized as hemodynamic allostasis. The purpose of our study was to determine the role of hemodynamic parameters in allostatic load in patients with EH without metabolic syndrome. Twenty-four hours of ambulatory blood pressure monitoring was performed, followed by linear and non-linear rhythm analysis. Based on the daily index, patients with EH were divided into two groups: group 1—patients with no significant nighttime decrease in blood pressure (BP); group 2—patients who had a nocturnal decrease in BP. The control group included healthy persons aged 25 to 69 years. A linear analysis was used to determine the mean values of systolic and diastolic BP, heart rate (HR), time load of BP, circadian index, and structural point of BP. Non-linear analysis was applied to determine the mesor, amplitude, range of oscillations and % rhythm of BP and HR. The allostatic load index (ALI) was also calculated on the basis of the corresponding biomarkers. It was found that ALI was significantly higher in groups 1 and 2 in comparison with the control group. The hemodynamic mechanisms of this increase were different.

Kv12-encoded K+ channels drive the day-night switch in the repetitive firing rates of SCN neurons.

Considerable evidence suggests that day-night rhythms in the functional expression of subthreshold potassium (K+) channels regulate daily oscillations in the spontaneous firing rates of neurons in the suprachiasmatic nucleus (SCN), the master circadian pacemaker in mammals. The K+ conductance(s) driving these daily rhythms in the repetitive firing rates of SCN neurons, however, have not been identified. To test the hypothesis that subthreshold Kv12.1/Kv12.2-encoded K+ channels play a role, we obtained current-clamp recordings from SCN neurons in slices prepared from adult mice harboring targeted disruptions in the Kcnh8 (Kv12.1-/-) or Kcnh3 (Kv12.2-/-) locus. We found that mean nighttime repetitive firing rates were higher in Kv12.1-/- and Kv12.2-/- than in wild type (WT), SCN neurons. In marked contrast, mean daytime repetitive firing rates were similar in Kv12.1-/-, Kv12.2-/-, and WT SCN neurons, and the day-night difference in mean repetitive firing rates, a hallmark feature of WT SCN neurons, was eliminated in Kv12.1-/- and Kv12.2-/- SCN neurons. Similar results were obtained with in vivo shRNA-mediated acute knockdown of Kv12.1 or Kv12.2 in adult SCN neurons. Voltage-clamp experiments revealed that Kv12-encoded current densities in WT SCN neurons are higher at night than during the day. In addition, the pharmacological block of Kv12-encoded currents increased the mean repetitive firing rate of nighttime, but not daytime, in WT SCN neurons. Dynamic clamp-mediated subtraction of modeled Kv12-encoded currents also selectively increased the mean repetitive firing rates of nighttime WT SCN neurons. Despite the elimination of the nighttime decrease in the mean repetitive firing rates of SCN neurons, however, locomotor (wheel-running) activity remained rhythmic in Kv12.1-/-, Kv12.2-/-, and Kv12.1-targeted shRNA-expressing, and Kv12.2-targeted shRNA-expressing animals.

"Arterial stiffness is not associated with changes in the circadian pattern of blood pressure in patients with type 1 diabetes mellitus and cardiovascular autonomic dysfunction".

Cardiovascular autonomic neuropathy (CAN) associates an abnormal circadian pattern in blood pressure (BP) regulation that might be aggravated by the coexistence of arterial stiffness. We aimed to evaluate the effect of arterial stiffness in the circadian rhythm of BP in patients with type 1 diabetes and CAN. Cross-sectional study including 56 consecutive patients with type 1 diabetes and CAN, with (n = 28) or without (n = 24) arterial stiffness as defined by an ankle-brachial index above 1.2. CAN was diagnosed by BP and heart rate responses to active standing and cardiovascular autonomic reflex tests. Absence of nocturnal decrease in BP-"non-dipping" pattern- was defined by a daytime to nighttime decrease in mean BP smaller than 10%. The study's subjects mean age was 40 ± 11 years-old, their mean duration of diabetes was 22 ± 10 years, and their mean A1c was 7.9 ± 1.5%. A "non-dipping" pattern was observed in 28 patients (54%) regardless of the presence or absence of arterial stiffness. Age, waist circumference, body mass index, and A1c, were introduced as independent variables into a multiple regression analysis. The stepwise model (R2: 0.113, p = 0.016) retained only A1c levels (β: ‒ 0.333, 95% confidence interval [CI]: -3.10 to -0.33) as significant predictor of the percentage of nighttime decrease in mean BP. A non-dipping pattern in BP is very common in patients with type 1 diabetes presenting with subclinical CAN and is associated with a poorer metabolic control. On the contrary, coexistence of arterial stiffness is not associated with abnormalities in circadian BP regulation.

Daily profile of arterial and central aortic pressure in patients with arterial hypertension and non-alcoholic fatty liver disease

Оbjective : to evaluate the features of daily monitoring of arterial and central aortic pressure in patients with arterial hypertension and non-alcoholic fatty liver disease. Materials and methods: a comparative cross-sectional study was conducted, which involved 120 patients (continuous sample, unorganized population), aged 45 to 65 years (mean age 56.2±8.8 years), including men (34 (28.3%) with AH stage I–II, 1–2 degree. The main group included 60 patients with hypertension and NAFLD, the control group included 60 patients with isolated hypertension. When examining patients, a clinical examination was carried out: taking an anamnesis, measuring "office" blood pressure, anthropometric parameters, calculating body mass index (BMI), WC. 24-hour monitoring of arterial (ABPM) and central aortic pressure (CAP) was assessed using the BPLab complex and Vasotens 24 software (LLC Petr Telegin, Russia). The SCORE scale was used to calculate total cardiovascular risk and 10-year fatal risk. Results : all patients of the study groups underwent ABPM. It was proved that in the patients of the main group, the IV SBP and IV DBP during the day and night significantly exceeded the similar parameters of patients in the comparison group (IV SBP: p=0.0019, p=0.007; IV DBP: p=0.009, p=0.009, respectively). One of the important criteria for assessing blood pressure was the determination of the degree of nighttime decrease in SBP and DBP — the daily index (SI), characterizing the balance in the work of the sympathetic and parasympathetic parts of the autonomic nervous system. In the main group, compared with the control group, there were more patients with SI DBP in the range from 0.0% to 10.0% (non-dipper) (p=0.034), with an increase in SBP at night (night-picker) (p=0.031). When assessing the parameters of CAP, in patients with AH and NAFLD, statistically significantly higher values of mean daily systolic (SADAo) and diastolic (DADo) aortic pressure were observed (p=0.016, p=0.039, respectively), SBP in the daytime (p=0.027), SADao and DADAO at night (p=0.002, p=0.003, respectively), compared with patients with isolated hypertension. Calculation of the risk of cardiovascular complications, in patients with hypertension and NAFLD, a significant increase in the 10-year risk of cardiovascular events was determined, compared with patients with isolated hypertension (3.7 (1.6; 6.0) vs 2.0 (0.6 ;4.3) %, p=0.013). Conclusion : according to the results of 24-hour BP monitoring, in patients with AH and NAFLD, compared with patients with isolated AH, a more significant increase in mean SBP and DBP, an increase in the rate of morning rise and BP variability, and the hypertension time index were revealed. In the main group, patients with a nocturnal increase in SBP were detected significantly more often, which indicates a greater risk of cardiovascular complications in patients with hypertension and NAFLD. In addition, compared with patients with isolated AH, patients with AH and NAFLD showed more significant increases in average daily and nighttime SBPao and DADAO.

Daily profiles of blood pressure in patients with arterial hypertension of various psychotypes

Аim: to assess the influence of the patient's psychotype on the degree of nighttime reduction in blood pressure (BP) to determine predictors of an unfavorable daily BP profile.Materials and methods. The study involved 80 patients with newly diagnosed or untreated arterial hypertension (AH), with various stages, severity, risk of developing cardiovascular complications, in the absence of concomitant severe somatic pathology, who independently consulted a local therapist. All patients underwent 24-hour blood pressure monitoring in the absence of antihypertensive therapy and the psychological profile was assessed using the SMOL questionnaire.Results. The psychopathological profile of the examined AH patients corresponded to the social and psychological adaptation. Our analysis of the indices of the averaged profile of the SMOL test, depending on the degree of reduction in nocturnal systolic blood pressure (between dipper and non-dipper profiles) and diastolic blood pressure (between dipper, non-dipper and extreme dipper patterns profiles) did not reveal statistically significant differences (p > 0,05). Patients with a riser daily blood pressure profile, due to the small size of the group, were not included in the comparative analysis. The average profile of SMOL of the examined patients was noted by an increase in indicators on the scales 1 – hypochondria and 3 – emotional lability.Conclusion. The variant of the daily blood pressure profile does not depend on the psychotype of the patient; it is likely that functional and structural changes that occur during the formation of hypertension affect the type of the degree of nighttime decrease in blood pressure.

Prognostic value of 24-hour ambulatory blood pressure patterns in diabetes: A 21-year longitudinal study.

To establish the long-term prognostic value of abnormal circadian blood pressure (BP) patterns in diabetes. We retrospectively examined a cohort of 349 outpatients with diabetes who were screened for microvascular complications and followed up for 21 years. Dipping, nondipping and reverse-dipping status were defined based on 24-hour ambulatory BP monitoring (ABPM) as ≥10% reduction, <10% reduction, and any increase in average nighttime versus daytime systolic BP (SBP), respectively. After 6251 person-years of follow-up (median [range] follow-up 21.0[1.1-22.0]years, 52% women, age 57.1 ± 11.9 years, 81.4% type 2 diabetes and 18.6% type 1 diabetes), a total of 136 deaths (39%) occurred. Compared with dippers, the nondippers and reverse dippers showed progressively higher prevalence of chronic kidney disease (CKD), cardiac autonomic neuropathy (CAN) and postural hypotension. Reverse dippers showed a 13.4% (2.5-year) reduction in mean overall survival and a twofold increased risk of all-cause mortality after adjustment for traditional risk factors (hazard ratio 2.2 [95% confidence interval 1.3-3.8]). Each 1% decrease in nighttime versus daytime SBP ratio was independently associated with a 4% reduction in 20-year mortality risk. In patients with diabetes, reverse dipping is associated with a higher prevalence of CKD and CAN and more than doubled the adjusted risk of all-cause mortality over a 21-year observation.

14 THE THERAPEUTIC VALUES OF CATHETER-BASED RENAL DENERVATION PROCEDURE AGAINST RESISTANT HYPERTENSION IN PATIENTS WITH OR WITHOUT CHRONIC KIDNEY DISEASE: REVISITING THE PROMISING PROSPECT - A SYSTEMATIC REVIEW AND META-ANALYSIS

Background: The increasing incidence of uncontrolled hypertension despite a greater number of therapies has been described as the “hypertension paradox”. CKD often complicates antihypertensive treatment by rendering the disease resistant to treatment. Recently, catheter-based renal denervation has reemerged as potential treatment for resistant hypertension. Several trials reported significant SBP-lowering effects in patients treated with catheter-based renal denervation. Objective: This meta-analysis aims to summarize the antihypertensive properties of renal denervation to control SBP in patients with resistant hypertension with CKD. Methods: Systematic review and meta-analysis were conducted with literatures from ProQuest, Elsevier, SpringerLink, and Oxford Academic to PRISMA Guidelines for RCTs regarding SBP management with renal denervation for resistant hypertension patients with or without CKD using Renal Denervation, Resistant Hypertension, Systolic Blood Pressure and Chronic Kidney Disease as keywords. Results: Six literatures were analyzed, consisting of 730 patients with resistant hypertension with or without CKD. The subjects underwent catheter-based renal denervation in comparison to sham procedures, in RCTs for 2-12 months. These trials exhibit beneficial antihypertensive effects of renal denervation, reducing the ambulatory 24-hour SBP (MD -8.5[-15.1 to 0.0] vs. MD -2.9[-12.6 to 2.5]; p=0.016) 2-months post-procedure. Other literatures also reported major office SBP decrease (180 mmHg ±12 to 149.0 mmHg ±11 vs. 181.0 mmHg ±19 to 179.0 mmHg ±5; p=0.007) 12-months post-procedure. Another shows significant decrease in daytime (MD -12mmHg ±18; p&lt;0.001) and nighttime (MD -8mmHg ±19; p&lt;0.013) SBP. Conclusion: Renal denervation showed significant SBP lowering effects in patients with resistant hypertension based on evidences exhibited. Further research is necessary to provide more evidence to support this outcome.

Active Nitrogen Cycle Driven by Solar Radiation in Clean Desert Air

AbstractDeserts have been recognized as constantly releasing reactive nitrogen compounds to the atmosphere due to the subsoil‐storage leaching and surface‐deposit evaporation induced by solar radiative heating. However, this release and the consequent response of the nitrogen cycles in desert air have not been evaluated and are overlooked in most regional and global models. In our nitrate measurements, including nitric acid and particulate nitrate, in clean air, that is, in the absence of or with minor anthropogenic influences, in a Chinese desert, diurnal nitrate variations consisting of daytime increases and nighttime decreases were observed in the range of 1.3–3.7 μgm−3 in summer, 0.1–2.6 μgm−3 in spring, and 0.2–1.3 μgm−3 in autumn. These values are considerably higher than those observed in remote marine and forest areas. Simulations with a regional transport model demonstrate that the variation could be largely accounted for by the oxidation of soil‐emitted reactive nitrogen compounds by photochemical‐reactions products. These results indicate an active nitrogen cycle in clean desert air, which is the consequence of the coordination of solar radiation‐induced surface soil emission and subsequent photochemical reactions. Satellite data of NO2 further indicate possible similar cycles in most major desert areas worldwide. By including this nitrogen cycle in the vast desert areas and its subsequent effects, such as those on ozone chemistry, climate models may thus provide a better understanding of the global nitrogen budget in the historical and developing Earth ecosystems.

Daytime Exposure to Blue Light Alters Cardiovascular Circadian Rhythms, Electrolyte Excretion and Melatonin Production.

Artificial light is characterized by certain features of its impact on the body in terms of its spectral distribution of power, duration of exposure and intensity. Short waves, perceived as blue light, are the strongest synchronizing agent for the circadian system. In the present work, we investigated the features of the circadian rhythms of blood pressure (BP), heart rate (HR), the excretion of electrolytes and the secretion of melatonin in normotensive (Wistar–Kyoto) and hypertensive (SHR) rats under the action of monochromatic blue light in the daytime period. It was found that the exposure of Wistar–Kyoto rats to monochromatic blue light was accompanied by a significant decrease in nighttime and 24 h systolic BP. The most remarkable changes are characteristic of the HR in SHR rats under monochromatic light. A significant decrease in HR in each time period was found, but the predominance of nighttime over daytime values remained in SHR animals. There was also a significant increase in the mesor of the HR in SHR rats. Additionally, the amplitude of diastolic BP and HR, as well as the range of oscillations in HR, were significantly increased compared with the standard light pattern. In contrast to SHR rats, the regulation of the circadian rhythms in Wistar–Kyoto rats was more flexible and presented more changes, which may be aimed at the adaptation of the body to environmental conditions. For Wistar–Kyoto rats, an increase in the level of excreted electrolytes was observed under the action of monochromatic light, but no similar changes were found in SHR rats. For Wistar–Kyoto rats, a significant decrease in the urine concentration of aMT6s in the daytime and nighttime periods is characteristic, which results in the loss of the circadian rhythm. In SHR rats, there was a significant decrease in the nighttime content of aMT6s in the urine, while the daytime concentration, on the contrary, increased. The obtained data demonstrate that prolonged exposure to monochromatic blue light in the daytime period affects the circadian structure of the rhythms of the cardiovascular system, the rhythm of electrolyte excretion and the production of epiphyseal melatonin in wild-type and hypertensive animals. In SHR rats, the rhythms of BP and HR exhibit a more rigid pattern.

Diurnal blood pressure variation in adults after abdominal surgery–An observational cohort study

ObjectiveTo describe the prevalence of various circadian blood pressure patterns in adults recovering from abdominal surgery, and to evaluate the association between loss of normal circadian variation in blood pressure and hypotension during the initial 2 postoperative days. DesignA post-hoc analysis of data obtained from two randomized trials. SettingOperating rooms of the Cleveland Clinic. PatientsAdults having abdominal surgery from 2015 to 2019 with at least one overnight stay. Participants were continuously monitored by wearable vital signs monitors starting in the post-anesthesia care unit and for the first 48 postoperative hours. InterventionsNone. The exposure of interest was the degree of nocturnal decrease in blood pressure - normal nocturnal decrease in blood pressure (“normal dipping”, more than 10% decrease compared to day-time), no nocturnal decrease (“non-dipping”, less than 10% nocturnal decrease), or nocturnal increase in blood pressure (“rising”). MeasurementsPostoperative hypotension, defined by the time weighted average (TWA) area under a mean arterial pressure (MAP) threshold of 70 mmHg. ResultsIn total, 590 patients were eligible for analysis (mean(SD) age 50(15) years, 56% females, median [IQR] surgery duration 4.0 [2.7, 5.8] hours). Median TWA area under a MAP threshold of 70 mmHg was 0.96 (95%CI 0.59, 1.33) mmHg*minute per monitoring hour lower in patients with either no nocturnal blood pressure decrease (N = 317, 54%), or an increase in nocturnal blood pressure (N = 211, 36%), than in the reference group of patients with normal nocturnal decrease (N = 62, 11%), P < 0.001 for both. ConclusionsAbnormal diurnal blood pressure patterns are common in adults during the initial 2 days after abdominal surgery. Lack of normal night-time decrease in blood pressure is associated with less postoperative hypotension. Future studies should evaluate whether abnormal postoperative diurnal blood pressure patterns are associated with worse outcomes.

Relationship between renal function and blood pressure dipping status in renal transplant recipients: a longitudinal study

BackgroundHypertension (HT) is associated with adverse outcomes in kidney transplant (KTX) recipients. Blunting of physiological decrease in nighttime compared to daytime blood pressure (non-dipping status) is frequent in this setting. However, weather non-dipping is independently associated with renal function decline in KTX patients is unknown.MethodsWe retrospectively screened KTX outpatients attending for a routine ambulatory blood pressure monitoring (ABPM) (T1) at a single tertiary hospital. Patients had two successive follow-up visits, 1 (T2) and 2 (T3) years later respectively. Routine clinical and laboratory data were collected at each visit. Mixed linear regression models were used with estimated glomerular filtration rate (eGFR) as the dependent variable.ResultsA total of 123 patients were included with a mean follow-up of 2.12 ± 0.45 years after ABPM. Mean age and eGFR at T1 were 56.0 ± 15.1 and 54.9 ± 20.0 mL/min/1.73m2 respectively. 61 patients (50.4%) had sustained HT and 81 (65.8%) were non-dippers. In multivariate analysis, systolic dipping status was positively associated with eGFR (p = 0.009) and compared to non-dippers, dippers had a 10.4 mL/min/1.73m2 higher eGFR. HT was negatively associated with eGFR (p = 0.003).ConclusionsWe confirm a high prevalence of non-dippers in KTX recipients. We suggest that preserved systolic dipping is associated with improved renal function in this setting independently of potential confounders, including HT and proteinuria. Whether modification of dipping status by chronotherapy would preserve renal function remains to be tested in clinical trials.

Трехкомпонентная комбинированная антигипертензивная терапия у больных артериальной гипертензией с абдоминальным ожирением. Данные 9-месячного наблюдения

Актуальность. Сочетанное течение первичной артериальной гипертензии (АГ) и абдоминального ожирения (АО) характеризуется рефрактерностью к антигипертензивной терапии и значительным повышением сердечно-сосудистого риска. Перспективным подходом к терапии данных больных является раннее применение фиксированных комбинаций антигипертензивных препаратов первой линии. Цель работы состояла в исследовании эффективности фиксированной комбинации периндоприла, индапамида и амлодипина в сравнении с нефиксированной комбинацией указанных препаратов у больных с АГ в сочетании с АО. Материалы и методы. Обследованы 75 больных с АГ II–III степени в сочетании с АО І–ІІ степени (45 мужчин и 30 женщин) в возрасте от 48 до 66 лет. Все больные были разделены на две подгруппы в зависимости от вида антигипертензивной терапии. Первая подгруппа больных (26 пациентов) получала нефиксированную комбинацию периндоприла, индапамида и амлодипина. Вторая подгруппа (29 больных) получала фиксированную комбинацию указанных препаратов. Обследование проводили до начала лечения и через 3, 6 и 9 месяцев. В качестве гиполипидемического препарата все больные получали аторвастатин в суточной дозе 20 мг. Указанная терапия проводилась на фоне рекомендаций по коррекции образа жизни. Результаты. Установлено, что частота достижения целевых уровней артериального давления (АД) у больных, которые получали фиксированную комбинацию препаратов, через 9 месяцев лечения была достоверно выше, чем у больных, которые получали нефиксированную комбинацию. По данным суточного мониторирования АД, фиксированная комбинация назначенных препаратов значительно лучше нормализовала такие параметры, как среднесуточное и среднедневное диастолическое АД (ДАД), средненочное систолическое АД (САД) и ДАД, а также степень ночного снижения и среднесуточную вариабельность САД и ДАД. Апробированная трехкомпонентная фиксированная комбинация давала возможность достичь целевых уровней АД на более низких дозах примененных компонентов, чем нефиксированная комбинация. Выводы. Фиксированная комбинация периндоприла, индапамида и амлодипина в сравнении с нефиксированной у больных АГ в сочетании с АО проявляет достоверно большую антигипертензивную эффективность по данным как офисного измерения АД, так и суточного мониторирования АД на фоне большей приверженности больных к лечению. Для достижения целевых уровней АД у больных АГ в сочетании с АО требуются более низкие дозы компонентов фиксированной комбинации, чем нефиксированной.

Abstract P199: Circadian Contributions To Blood Pressure Variation Under Constant Conditions

The circadian clock is an endogenous biological timekeeper that responds to environmental changes and governs various physiological processes over a 24-hour cycle. Blood pressure (BP) variation is thought to be controlled by the circadian clock, but few studies have examined circadian control of BP in humans. Moreover, it is unknown whether nighttime BP dipping is driven by the circadian system or by external factors. We investigated whether the circadian system drives 24-hour rhythms in BP, including nighttime BP dipping, using a 30-hour constant routine (CR) protocol. The CR protocol controls for external factors, allowing circadian rhythms to be isolated and measured, by having participants lie in a semi-recumbent posture in dim light (&lt;10 lux) at a constant temperature, consume isocaloric snacks every 2 hours, and maintain wakefulness. To measure the BP rhythm, ambulatory BP was measured every 30 minutes (SpaceLabs 90227), and to measure the central circadian rhythm, core body temperature was measured every 10 seconds using an ingestible, wireless sensor (HQInc Core Body Temperature Wireless Data Record and Sensor). To date, 17 normotensive African American participants (13 females and 4 males), with a mean age of 37 (± 11.3) years and body mass index (BMI) of 32.5 kg/m 2 , have completed the study. Approximately 59% of participants (10 of 17) had non-dipping systolic BP at screening, defined as a &lt;10% decrease in mean systolic BP from daytime to nighttime. Under constant conditions, 94% of participants (16 of 17) had a non-dipping BP phenotype. Median systolic BP dipping was 0.8% for females and 2.2% for males. There was a robust rhythm in participants’ core body temperature but not BP, suggesting that the circadian clock may not contribute substantially to a nighttime decrease in BP in normotensive African Americans. Instead, the non-dipping BP phenotype is likely more so a result of behavioral and/or physiological sleep-related processes. Future research and interventions for non-dipping BP may need to target these underlying behavioral and physiological processes.