Circadian Rhythm of Blood Pressure of Dipper and Non-dipper Patients With Essential Hypertension: A Mathematical Modeling Approach

Prediction of non-dipper blood pressure pattern in Chinese patients with hypertension using a nomogram model

Non-dipper blood pressure has been shown to affect cardiovascular outcomes and cognitive function in patients with hypertension. Although some studies have explored the influencing factors of non-dipper blood pressure, there is still relatively little research on constructing a prediction model. This study aimed to develop and validate a simple and practical nomogram prediction model and explore relevant elements that could affect the dipper blood pressure relationship in patients with hypertension. A convenient sampling method was used to select 356 inpatients with hypertension who visited the Affiliated Hospital of Jining Medical College from January 2022 to September 2022. All patients were randomly assigned to the training cohort (75%, n = 267) and the validation cohort (25%, n = 89). Univariate and multivariate logistic regression were utilized to identify influencing factors. The nomogram was developed and evaluated based on the receiver operating characteristic (ROC) curve, the area under the ROC curve (AUC), and decision curve analyses. The optimal cutoff values for the prevalence of dipper blood pressure were estimated. The nomogram was established using six variables, including age, sex, hemoglobin (Hb), estimated glomerular filtration rate (eGFR), ejection fraction (EF), and heart rate. The AUC was 0.860 in the training cohort. The cutoff values for optimally predicting the prevalence of dipper blood pressure were 41.50 years, 151.00 g/L, 117.53 mL/min/1.73 m2, 64.50%, and 75 beats per minute for age, Hb, eGFR, ejection fraction, and heart rate, respectively. In summary, our nomogram can be used as a simple, plausible, affordable, and widely implementable tool to predict the blood pressure pattern of Chinese patients with hypertension.

Effects of DASH diet with or without time-restricted eating in the management of stage 1 primary hypertension: a randomized controlled trial

BACKGROUND

Time-restricted eating (TRE), a popular form of intermittent fasting, has shown benefits for improving metabolic diseases and cardiometabolic health. However, the effect of TRE in the regulation of blood pressure in primary hypertension remains unclear.

METHODS

A 6-week randomized controlled trial was conducted, in which a total of 74 stage 1 primary hypertensive patients without high-risk were randomly assigned to Dietary Approaches to Stop Hypertension (DASH) group (n = 37) or DASH + TRE group (n = 37). Participants in the DASH + TRE group were instructed to consume their food within an 8-h window. Scientific research platform in We Chat application was used to track participants. The primary outcome was blood pressure. The secondary outcomes included body composition, cardiometabolic risk factors, inflammation-related parameters, urinary Na+ excretion, other clinical variables and safety outcomes.

RESULTS

The reduction of systolic blood pressure and diastolic blood pressure were 5.595 ± 4.072 and 5.351 ± 5.643 mm Hg in the DASH group and 8.459 ± 4.260 and 9.459 ± 4.375 mm Hg in the DASH + TRE group. DASH + TRE group improved blood pressure diurnal rhythm. Subjects in DASH + TRE group had decreased extracellular water and increased urinary Na+ excretion. Furthermore, the decrease in blood pressure was associated with a reduction of extracellular water or increase in urinary Na+ excretion. In addition, safety outcomes such as nighttime hunger were also reported.

CONCLUSION

Our study demonstrated that 8-h TRE + DASH diet caused a greater decrease in blood pressure in stage 1 primary hypertensive patients than DASH diet. This study may provide novel insights into the benefits of lifestyle modification in the treatment of primary hypertension.

TRIAL REGISTRATION

https://www.chictr.org.cn/ (ChiCTR2300069393, registered on March 15, 2023).

Study on blood pressure rhythm in hypertensive patients withdeficiency syndrome and a random forest model for predicting hypertension withdeficiency syndrome

OBJECTIVE

To investigate blood pressure rhythm (BPR) in Yin deficiency syndrome of hypertension (YDSH) patients and develop a random forest model for predicting YDSH.

METHODS

Our study was consistent with technical processes and specification for developing guidelines of Evidence-based Chinese medicine clinical practice (T/CACM 1032-2017). We enrolled 234 patients who had been diagnosed with primary hypertension without antihypertensive medications prior to the enrollment. All participants were divided into Yin deficiency group (YX, n = 74) and non-Yin deficiency group (NYX, n = 160). Participants were professionally grouped by three experienced chief Traditional Chinese Medicine (TCM) physicians according to four examinations (i.e., inspection, listening and smelling, inquiry and palpation). We collected data on 24 h ambulatory blood pressure monitoring (ABPM) and YDSH rating scale. We divided 24 h of a day into 12 two-hour periods [Chen-Shi (7:00-9:00), Si-Shi (9:00-11:00), Wu-Shi (11:00-13:00), Wei-Shi (13:00-15:00), Shen-Shi (15:00-17:00), You-Shi (17:00-19:00), Xu-Shi (19:00-21:00), Hai-Shi (21:00-23:00), Zi-Shi (23:00-1:00), Chou-Shi (1:00-3:00), Yin-Shi (3:00-5:00), Mao-Shi (5:00-7:00)] according to the theory of "midnight-midday ebb flow". We used random forest to build the diagnostic model of YDSH, with whether it was Yin deficiency syndrome as the outcome.

RESULTS

Compared with NYX group, YX group had more female participants with older age, lower waist circumference, body mass index (BMI), diastolic blood pressure (DBP), and smoking and drinking rate (all P ＜ 0.05). The YDSH rating scores of YX group [28.5 (21.0-36.0)] were significantly higher than NYX group [13.0 (8.0-22.0)] (P < 0.001), and the typical symptoms of YX group included vexing heat in the chest, palms and soles, dizziness, dry eyes, string-like and fine pulse, soreness and weakness of lumbus and knees, palpitations, reddened cheeks, and tinnitus (all P < 0.05). The ratio of non-dipper hypertension in YX group was higher than in NYX group (56.9% vs 44.4%, P = 0.004). Compared with NYX group, 24 h DBP standard deviation (SD), nighttime DBP SD, Si-Shi DBP, Si-Shi mean arterial pressure (MAP), Hi-Shi systolic blood pressure (SBP), Hi-Shi DBP, Hi-Shi MAP, Zi-Shi SBP, Zi-Shi DBP, Zi-Shi MAP, Chou-Shi SBP SD, Chou-Shi DBP SD, Chou-Shi SBP coefficient of variation (CV) were lower in YX group (all P ＜ 0.05). Binary Logistic Regression analysis showed that the diagnosis of YDSH was positively correlated with age, heart rate, YDSH rating scores, and four TCM symptoms including vexing heat in the chest, palms and soles, string-like and fine pulse, soreness and weakness of lumbus and knees, and reddened cheeks (all P ＜ 0.05), but was negatively correlated with smoking (P﹥0.05). In addition, the diagnosis of YDSH was positively correlated with daytime SBP SD, nighttime SBP SD, nighttime SBP CV, and Hi-Shi SBP CV, but was negatively correlated with 24 h SBP CV, daytime DBP SD, nighttime DBP SD, and Hi-Shi DBP (all P ＜ 0.05). Hi-Shi SBP CV had independent and positive correlation with the diagnosis of YDSH after adjusting the variables of age, gender, course of hypertension, BMI, waist circumference, SBP, DBP, heart rate, smoking and drinking (P = 0.029). Diagnostic model of YDSH was established and verified based on the random forest. The results showed that the calculation accuracy, specificity and sensitivity were 77.3%, 77.8% and 76.9%, respectively.

CONCLUSION

The BPR was significantly attenuated in YDSH patients, including lower 24 h DBP SD and nighttime DBP SD, and Hi-Shi SBP CV is independently correlated with the diagnosis of YDSH. The prediction accuracy of diagnosis model of YDSH based on the random forest was good, which could be valuable for clinicians to differentiate YDSH and non-Yin deficiency patients for more effective hypertensive treatment of TCM.

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.

The effect of bedtime versus morning dosing of antihypertensive drugs on the cardiovascular outcomes: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND AND OBJECTIVE

Antihypertensive drugs are one of the most effective strategies to prevent disability and mortality; however, there have been contradictory findings about the best dosing time for antihypertensive drugs. Therefore, we aim to evaluate the effect of bedtime versus morning dosing of antihypertensive drugs on cardiovascular outcomes.

METHODS

We synthesized randomized controlled studies (RCTs) from the Web of Science, SCOPUS, EMBASE, PubMed, and CENTRAL until 13 October 2022. The risk ratio (RR) for dichotomous outcomes with the corresponding 95% confidence interval (CI) was used. The study protocol was registered in PROSPERO with ID: CRD42022368612.

RESULTS

Five RCTs with 59 200 participants were included. Bedtime dosing was significantly associated with less incidence of myocardial infarction (MI) [RR: 0.80 with 95% CI (0.70-0.91), P = 0.0007] compared with morning dosing; however, there was no statistically significant difference between bedtime and morning dosing, regarding all-cause mortality [RR: 0.77 with 95% CI (0.51-1.16), P = 0.21], cardiovascular mortality [RR: 0.65 with 95% CI (0.35-1.21), P = 0.17], major adverse cardiac events (MACE) [RR: 0.79 with 95% CI (0.56-1.10), P = 0.16], heart failure [RR: 0.68 with 95% CI (0.42-1.09), P = 0.11], cerebrovascular accidents [RR: 0.80 with 95% CI (0.53-1.22), P = 0.30], coronary revascularization [RR: 0.79 with 95% CI (0.50-1.24), P = 0.30}, and angina [RR: 0.91 with 95% CI (0.55-1.50), P = 0.70].

CONCLUSION

Evidence about the comparative efficacy of bedtime versus morning dosing of antihypertensives is still uncertain. However, bedtime dosing significantly reduced MI, which warrants more robust RCTs to validate.

Effect of administration of low-dose irbesartan and hydrochlorothiazide combined with levamlodipine at different times on the circadian rhythm of blood pressure and the levels of MMPs and TIMPs in non-dipper patients with grade 1 and 2 hypertension

This study aimed to probe the effects of low-dose irbesartan and hydrochlorothiazide in combination with levamlodipine at different times on the circadian rhythm of blood pressure, matrix metalloproteinases (MMPs), and tissue inhibitors of metalloproteinases (TIMPs) levels in patients with non-dipper hypertension (NDH). In this prospective randomized controlled trial, 124 patients with NDH who visited our hospital between August 2018 and July 2021 were enrolled and divided into morning (62 patients) and night (62 patients) medication groups according to the random number table method. All patients received low-dose irbesartan and hydrochlorothiazide combined with levamlodipine, with the morning medication group taking the medication between 7:00 and 10:00 and the night medication group taking the medication between 19:00 and 22:00 for 24 weeks. The effect of antihypertensive medication in both groups was measured, and changes in ambulatory blood pressure, blood pressure circadian rhythm, left ventricular structure, vascular endothelial function, MMPs, and TIMPs levels were observed before treatment initiation and after 24 weeks of treatment in both groups. The percentage of the dipper type was higher in the night medication group than in the morning medication group, while the percentage of the non-dipper type was lower in the morning medication group (p < .05). Low-dose irbesartan and hydrochlorothiazide combined with levamlodipine at different times can effectively treat NDH, but bedtime dosing is more beneficial in reducing nocturnal blood pressure, reversing NDH, improving the circadian rhythm of blood pressure, left ventricular structure, regulating vascular endothelial function, increasing MMPs levels, and reducing TIMP levels.

Understanding the dosing-time-dependent antihypertensive effect of valsartan and aspirin through mathematical modeling

Chronopharmacology of arterial hypertension impacts the long-term cardiovascular risk of hypertensive subjects. Therefore, clinical and computational studies have proposed optimizing antihypertensive medications' dosing time (Ta). However, the causes and mechanisms underlying the Ta-dependency antihypertensive effect have not been elucidated. Here we propose using a Ta- dependent effect model to understand and predict the antihypertensive effect of valsartan and aspirin throughout the day in subjects with grade I or II essential hypertension. The model based on physiological regulation mechanisms includes a periodic function for each parameter that changes significantly after treatment. Circadian variations of parameters depending on the dosing time allowed the determination of regulation mechanisms dependent on the circadian rhythm that were most relevant for the action of each drug. In the case of valsartan, it is the regulation of vasodilation and systemic vascular resistance. In the case of aspirin, the antithrombotic effect generates changes in the sensitivity of systemic vascular resistance and heart rate to changes in physical activity. Dosing time-dependent models predict a more significant effect on systemic vascular resistance and blood pressure when administering valsartan or aspirin at bedtime. However, circadian dependence on the regulation mechanisms showed different sensitivity of their circadian parameters and shapes of functions, presenting different phase shifts and amplitude. Therefore, different mechanisms of action and pharmacokinetic properties of each drug can generate different profiles of Ta-dependence of antihypertensive effect and optimal dosing times.

Retinal arterial macroaneurysm rupture by Valsalva maneuver: a case report and literature review

BACKGROUND

Retinal artery macroaneurysms (RAMs) are focal dilations of the large retinal arteries. Most RAMs are asymptomatic, however, when hemorrhage or exudation caused by a RAM involves the macula, patients can experience marked vision loss. This article reported a rare case of a ruptured RAM due to the Valsalva maneuver in an elderly female with constipation and offered a review of the relevant literature.

CASE PRESENTATION

A 78-year-old woman with several risk factors presented with multi-level retinal hemorrhages following a Valsalva maneuver during constipation. Due to the poor coagulation and heavy bleeding in this case, the blood broke through the internal limiting membrane and drained "on its own" into the vitreous cavity. First, we observed the patient and controlled for her risk factors. After the blood was completely drained into the vitreous cavity, the root cause of the bleeding was found to be a RAM rupture. After laser photocoagulation, the patient's vision recovered significantly and remained stable for a long time despite the presence of an epiretinal membrane and a lamellar macular hole.

CONCLUSIONS

This is the first reported case of a RAM rupture by Valsalva maneuver during constipation. For multi-level hemorrhages caused by RAM, measures should be taken to drain out the sub-internal limiting membrane hemorrhage and simultaneously control for risk factors. After the RAM is exposed, laser photocoagulation can be performed.

Dosing time optimization of antihypertensive medications by including the circadian rhythm in pharmacokinetic-pharmacodynamic models

Blood pressure (BP) follows a circadian variation, increasing during active hours, showing a small postprandial valley and a deeper decrease during sleep. Nighttime reduction of 10–20% relative to daytime BP is defined as a dipper pattern, and a reduction of less than 10%, as a non-dipper pattern. Despite this BP variability, hypertension’s diagnostic criteria and therapeutic objectives are usually based on BP average values. Indeed, studies have shown that chrono-pharmacological optimization significantly reduces long-term cardiovascular risk if a BP dipper pattern is maintained. Changes in the effect of antihypertensive medications can be explained by circadian variations in their pharmacokinetics (PK) and pharmacodynamics (PD). Nevertheless, BP circadian variation has been scarcely included in PK-PD models of antihypertensive medications to date. In this work, we developed PK-PD models that include circadian rhythm to find the optimal dosing time (Ta) of first-line antihypertensive medications for dipper and non-dipper patterns. The parameters of the PK-PD models were estimated using global optimization, and models were selected according to the lowest corrected Akaike information criterion value. Simultaneously, sensitivity and identifiability analysis were performed to determine the relevance of the parameters and establish those that can be estimated. Subsequently, Ta parameters were optimized to maximize the effect on BP average, BP peaks, and sleep-time dip. As a result, all selected models included at least one circadian PK component, and circadian parameters had the highest sensitivity. Furthermore, Ta with which BP>130/80 mmHg and a dip of 10–20% are achieved were proposed when possible. We show that the optimal Ta depends on the therapeutic objective, the medication, and the BP profile. Therefore, our results suggest making chrono-pharmacological recommendations in a personalized way.

Neurodegenerative diseases and blood pressure variability: A comprehensive review from HOPE Asia

Asia has an enormous number of older people and is the primary contributor to the rise in neurodegenerative diseases such as Alzheimer's and Parkinson's disease. The therapy of many neurodegenerative diseases has not yet progressed to the point where it is possible to alter the course of the disease. Mid-life hypertension is an important predictor of later-life cognitive impairment and brain neurodegenerative conditions. These findings highlight the pivotal role of preventing and managing hypertension as a risk factor for neurodegenerative disease. Autonomic dysfunction, neuropsychiatric and sleep disturbances can arise in neurodegenerative diseases, resulting in blood pressure variability (BPV). The BPV itself can worsen the progression of the disease. In older people with neurodegenerative disease and hypertension, it is critical to consider 24-h blood pressure monitoring and personalized blood pressure therapy.