Isolated nocturnal hypertension in pediatric kidney transplant recipients

Ambulatory blood pressure profiles of children with asthma compared to healthy controls

BACKGROUND

Studies suggest that asthma and hypertension may be comorbid conditions. Most of these studies are epidemiological research. However, data on the relationship between asthma and hypertension in childhood are limited. We aimed to evaluate ambulatory blood pressure profiles of children with asthma.

METHODS

Children aged 5-18 with asthma were evaluated using ABPM. The control group included healthy age- and sex-matched volunteers. A total of 26 patients with asthma and 20 controls were enrolled.

RESULTS

Children with asthma had higher mean 24-h systolic blood pressure (SBP) SDS (standard deviation score) compared to controls (mean difference: 0.84, 0.19 ± 1.14 vs. - 0.65 ± 1.09, p = 0.015). Daytime SBP SDS was higher in those with asthma (mean difference: 0.83, 0.009 ± 1.22 vs. - 0.82 ± 1.09, p = 0.021), as was nighttime SBP SDS (mean difference: 0.74, 0.64 ± 1.09 vs. - 0.10 ± 0.79, p = 0.013). Median nighttime SBP load was higher in those with asthma (p = 0.006). Nondipping status was found in 23.1% of patients with asthma (none in controls, p = 0.021). One patient (3.8%) had ambulatory hypertension and six (23.1%) had masked hypertension (none in controls, p = 0.042). Extended use of inhaled corticosteroids was associated with a 2% increase in the odds of developing hypertension (OR 1.02, p = 0.025).

CONCLUSIONS

Children with asthma may be at greater risk for developing hypertension compared to healthy counterparts. Ambulatory blood pressure tends to be higher in children with asthma than healthy peers. Inhaled steroids potentially contribute to elevated BP levels in children with asthma.

Blood Pressure Estimation Based on PPG and ECG Signals Using Knowledge Distillation

OBJECTIVE

Easy access bio-signals are useful for alleviating the shortcomings and difficulties associated with cuff-based and invasive blood pressure (BP) measurement techniques. This study proposes a deep learning model, trained using knowledge distillation, based on photoplethysmographic (PPG) and electrocardiogram (ECG) signals to estimate systolic and diastolic blood pressures.

METHODS

The estimation model comprises convolutional layers followed by one bidirectional recurrent layer and attention layers. The training approach involves knowledge distillation, where a smaller model (student model) is trained by leveraging information from a larger model (teacher model).

RESULTS

The proposed multistage model was evaluated on 1205 subjects from Medical Information Mart for Intensive Care (MIMIC) III database using the Association for the Advancement of Medical Instrumentation (AAMI) and the standards of the British Hypertension Society (BHS). The results revealed that our model performance achieved grade A in estimating both systolic blood pressure (SBP) and diastolic blood pressure (DBP) and met the requirements of the AAMI standard. After training with knowledge distillation (KD), the model achieved a mean absolute error and standard deviation of 2.94 ± 5.61 mmHg for SBP and 2.02 ± 3.60 mmHg for DBP.

CONCLUSION

Our results demonstrate the benefits of the knowledge distillation training method in reducing the number of parameters and improving the predictive accuracy of the blood pressure regression model.

Treatment of Hypertension in Children

Hypertension is a real problem in children. It shows a tracking behaviour, representing a key risk factor for hypertension, cardiovascular disease, and end-organ failure in adulthood. However, the importance of addressing arterial hypertension in children is not limited to its risk of tracking into adulthood. Thus, early detection and management are crucial. Hypertension may be primary or due to secondary causes, and identification of this distinction is very important for the treatment setting. Importantly, the management of hypertension in children is crucial to prevent the well-known cardiovascular effects in adulthood. As demonstrated in the literature, healthy eating habits, together with regular physical activity, can have a major impact on reducing high blood pressure and preventing organ damage in children and adolescents. However, suppose these are not sufficient to treat hypertension. In that case, if patients are symptomatic and/or have additional metabolic conditions such as obesity, type diabetes mellitus, or chronic kidney disease, anti-hypertensive medication must be started. Recent guidelines have provided clear guidance on the treatment of hypertension and hypertensive crisis in pediatric age. On the other hand, there are currently few specific recommendations on the treatment of isolated nocturnal hypertension and treatment- resistant hypertension. This review aims to summarize the most recent recommendations for the treatment of hypertension and hypertensive crisis in children and the last years' knowledge and experience in treating childhood isolated nocturnal hypertension and resistant hypertension of childhood.

Denervation aggravates renal ischemia reperfusion injury via BMAL1-mediated Nrf2/ARE pathway

AIM

To explore the change of clock gene rhythm under renal denervation (RDN) and its effect on renal function and oxidative stress during renal ischemia-reperfusion (IR) injury.

METHOD

C57/BL6 mice were randomly divided into 4 groups at daytime 7 A M (zeitgeber time [ZT] 0) or at nighttime 7 P M (ZT12) in respectively: Sham (S) group, RDN group, IR group and RDN + IR (DIR) group. Renal pathological and functional changes were assessed by H&E staining, and serum creatinine, urea nitrogen and neutrophil gelatinase-associated lipocalin levels. Renal oxidative stress was detected by SOD and MDA levels, and renal inflammation was measured by IL-6, IL-17 A F and TNF-ɑ levels. BMAL1, CLOCK, Nrf2 and HO-1 mRNA and protein expressions were tested by qPCR and Western Blot.

RESULT

Compared with S groups, the rhythm of BMAL1, CLOCK and Nrf2 genes in the kidney were disordered in RDN groups, while renal pathological and functional indexes did not change significantly. Compared with IR groups, renal pathological and functional indexes were significantly higher in the DIR groups, as well as oxidative stress and inflammation in renal tissues. The nocturnal IR injury in the RDN kidney was the worst while the BMAL1, Nrf2 and HO-1 expressions were the highest. In DIR groups, renal injury was aggravated after the Brusatol treatment, but there was no significant improvement after the t-BHQ treatment at night, which might be consistent with the changes of Nrf2 and HO-1 protein expressions.

CONCLUSION

RDN lead to the disruption of BMAL1-mediated Nrf2 rhythm accumulation in the kidney, which reduced the renal ability to resist oxidative stress and inflammation, due to the impaired effect of activating Nrf2/ARE pathway in renal IR injury at nighttime.

Masked Hypertension in Healthy Children and Adolescents: Who Should Be Screened?

PURPOSE OF REVIEW

The goal is to review masked hypertension (MH) as a relatively new phenomenon when patients have normal office BP but elevated out-of-office BP. Firstly, it was described in children in 2004. It has received increased attention in the past decade.

RECENT FINDINGS

The prevalence of MH in different pediatric populations differs widely between 0 and 60% based on the population studied, definition of MH, or method of out-of-office BP measurement. The highest prevalence of MH has been demonstrated in children with chronic kidney disease (CKD), obesity, diabetes, and after heart transplantation. In healthy children but with risk factors for hypertension such as prematurity, overweight/obesity, diabetes, chronic kidney disease, or positive family history of hypertension, the prevalence of MH is 9%. In healthy children without risk factors for hypertension, the prevalence of MH is very low ranging 0-3%. In healthy children, only patients with the following clinical conditions should be screened for MH: high-normal/elevated office BP, positive family history of hypertension, and those referred for suspected hypertension who have normal office BP in the secondary/tertiary center.

Masked Hypertension in Pediatric Heart Transplant Recipients

BACKGROUND

Masked hypertension (HTN), especially, isolated nocturnal HTN (INH) has been shown to be a risk factor for cardiovascular disease (CVD) but is not studied well in pediatric heart transplant (PHT) patients. Ambulatory blood pressure monitoring (ABPM) is known to identify patients with HTN but is not used routinely in PHT.

METHODS

A single-center, prospective, cross-sectional study of PHT recipients was performed to observe the incidence of masked HTN using 24-h ABPM. The relationship between ABPM parameters and clinical variables was assessed using Spearman correlation coefficient. p value < 0.05 was considered significant.

RESULTS

ABPM was performed in 34 patients, mean age 14 ± 5 years, median 5.5 years post-PHT. All patients had normal cardiac function, left ventricular mass index and blood pressure measurements in the clinic. Four patients had known prior HTN and on medications, one of them was uncontrolled. Of the remaining 30 patients, 18 new patients were diagnosed with masked HTN, of which 14 had INH. Diurnal variation was abnormal in 82% (28/34) patients. 24-h diastolic blood pressure (DBP) index correlated with glomerular filtration rate (GFR) (r = - 0.44, p = 0.01). There was no correlation between other ABPM parameters with tacrolimus trough levels.

CONCLUSIONS

ABPM identified masked HTN in 60% of patients, with majority being INH. Abnormal circadian BP patterns were present in 82% and an association was found between GFR and DBP parameters. HTN, especially INH, is under-recognized in PHT recipients and ABPM has a role in their long-term care.

Isolated Nocturnal Hypertension in Children

Isolated nocturnal hypertension (INH) is attracting attention because it has been shown to correlate with target organ damage as well as cardiovascular events in adults. INH has also been reported in children especially in those with underlying diseases including chronic kidney disease and some studies reported association with markers of early target organ damage. INH occupies the majority of nocturnal hypertension. On the other hand, masked hypertension is largely attributed to INH. INH is usually diagnosed by ambulatory blood pressure monitoring. Recently, it became possible to monitor sleep blood pressure by an automated home blood pressure device feasible also in children. The epidemiology, methodology and reproducibility, pathophysiology, relation to target organ damage, and treatment of INH in children will be reviewed here along with adult data.