Salt sensitivity of blood pressure in childhood and adolescence

Effect of population-based sodium reduction interventions on blood pressure: a systematic review and meta-analysis of randomized trials

This systematic review and meta-analysis included cluster randomized controlled trials that compared population-based sodium reduction interventions with usual care for blood pressure (BP) management. We searched PubMed, Cochrane Central Register of Controlled Trials, and IchuShi-Web and utilized a random-effects meta-analysis of the weighted mean difference (MD) in the comparison groups to collect data from the included trials. The primary outcome includes the pooled MD of office BP from baseline to each follow-up period. This meta-analysis considered 36 articles with 66,803 participants to be eligible. The population-based sodium reduction interventions decreased office systolic BP (SBP) compared with usual care in 36 studies (MD: -2.64 mmHg [95% confidence interval: -3.48- to 1.80]), with evidence of heterogeneity. Office SBP exhibited significant benefits among in adults (30 studies) and adults/children (1 study) but not in children (5 studies). Furthermore, office diastolic BP demonstrated comparable benefits with office SBP. Sensitivity analyses by cluster type in adults revealed that the workplace-based intervention exerted a greater SBP-lowering effect than the clinic/facility-based intervention. However, no significant difference was observed in the SBP-lowering effect by intervention type. The interventions were more effective in hypertensive cohorts compared with non-hypertensive cohorts and in Asian cohorts compared with non-Asian cohorts. Additionally, the benefits for secondary outcomes, including salt (sodium chloride) intake, were similar to those for office BP. In conclusion, population-based sodium reduction interventions improved BP management compared with usual care. The benefits along with the observed heterogeneity should be considered prudent for implementation in public health and clinical practices. This meta-analysis considered 36 studies with 66,803 participants to be eligible. The population-based sodium reduction interventions decreased office BP compared with usual care in 36 studies, with evidence of heterogeneity. Sensitivity analyses by cluster type in adults (30 studies) revealed that community-, family-, school-, and workplace-based interventions reduced office SBP. Concerning intervention type, sodium reduction counseling, salt substitution, and monitoring decreased office SBP. Interventions were more effective in hypertensive cohorts compared with non-hypertensive cohorts. The benefits for salt intake (22 studies) and urinary sodium excretion (17 studies) were comparable to those for office BP. BP: blood pressure; DBP: diastolic blood pressure; MD: mean difference; Na: sodium; RR: risk ratio; SBP: systolic blood pressure.

Dietary Approaches to Stop Hypertension (DASH) dietary pattern is not associated with blood pressure in a cross-sectional sample of Australian primary schoolchildren

PURPOSE

The beneficial effects of the Dietary Approaches to Stop Hypertension (DASH) to reduce blood pressure among adults are well established. However, whether this dietary pattern is also relevant for the control of blood pressure in children remains unknown. Therefore, this study aimed to evaluate adherence to the DASH dietary pattern and examine its association with blood pressure among Australian primary schoolchildren.

METHOD

Cross-sectional data from 658 Australian children aged 8-12 years participating in the Salt and Other Nutrients In Children (SONIC) study were analyzed. One 24-hour diet recall was used to assess dietary intake. Systolic and diastolic blood pressure were measured with a digital automatic blood pressure machine. To assess adherence to the DASH dietary pattern a total DASH score (0-90) was created based on nine nutrient targets (protein, saturated fat, total fat, cholesterol, total fiber, sodium, potassium, magnesium, calcium). Multiple linear regression models were used to examine the association between the DASH score and blood pressure.

RESULTS

The mean total DASH score was 53.1 (SD 10.4) and was significantly different between boys (52.3) and girls (54.0) (p = 0.013). After controlling for covariates, no association between total DASH score and systolic or diastolic blood pressure was found.

CONCLUSION

Adherence to the DASH dietary pattern was moderate and there was no association between the DASH dietary pattern and blood pressure among Australian children aged 8-12 years.

Unraveling the gut microbiota's role in salt-sensitive hypertension: current evidences and future directions

The gut microbiota plays a pivotal role in both maintaining human health and in the pathogenesis of diseases. Recent studies have brought to light the significant correlation between gut microbiota and hypertension, particularly focusing on its role in the development and advancement of SSH, a subtype characterized by elevated blood pressure in response to high salt consumption. The complexity of SSH's etiology is notable, with dysbiosis of the gut microbiome identified as a crucial contributing factor. The gut microbiota participates in the occurrence and development of SSH by affecting the host's immune system, metabolic function, and neuromodulation. Investigations have demonstrated that the gut microbes regulate the development of SSH by regulating the TH17 axis and the activity of immune cells. Moreover, microbial metabolites, such as short-chain fatty acids, are implicated in blood pressure regulation and affect the development of SSH. There is evidence to show that the composition of the gut microbiome can be altered through prebiotic interventions so as to prevent and treat SSH. This review aims to concisely sum up the role of gut microbiota in SSH and to discuss pertinent therapeutic strategies and clinical implications, thereby providing a valuable reference for further research and clinical practice in this area.

Pathophysiology of primary hypertension in children and adolescents

The progress in research on the physiology of the cardiovascular system made in the last 100 years allowed for the development of the pathogenesis not only of secondary forms of hypertension but also of primary hypertension. The main determinants of blood pressure are described by the relationship between stroke volume, heart rate, peripheral resistance, and arterial stiffness. The theories developed by Guyton and Folkow describe the importance of the volume factor and total peripheral resistance. However, none of them fully presents the pathogenesis of essential hypertension. The multifactorial model of primary hypertension pathogenesis developed by Irving Page in the 1940s, called Page's mosaic, covers most of the pathophysiological phenomena observed in essential hypertension. The most important pathophysiological phenomena included in Page's mosaic form a network of interconnected "nodes". New discoveries both from experimental and clinical studies made in recent decades have allowed the original Page mosaic to be modified and the addition of new pathophysiological nodes. Most of the clinical studies confirming the validity of the multifactorial pathogenesis of primary hypertension concern adults. However, hypertension develops in childhood and is even perinatally programmed. Therefore, the next nodes in Page's mosaic should be age and perinatal factors. This article presents data from pediatric clinical trials describing the most important pathophysiological processes associated with the development of essential hypertension in children and adolescents.

Association between salt sensitivity of blood pressure and the risk of hypertension in a Chinese Tibetan population

Epidemiological studies have confirmed salt sensitivity as a crucial risk factor for the development of hypertension. However, few studies have investigated the association between salt sensitivity of blood pressure (SSBP) and hypertension in Chinese Tibetan population. Therefore, we conducted a cross-sectional study based on a Tibetan population to evaluate the association between SSBP and the risk of hypertension. Seven hundred and eighty-four participants with hypertension and 645 participants without hypertension were included from five villages in Tibetan Autonomous Region of Gannan during 2013-2014. The assessment of salt sensitivity (SS) and non-salt sensitivity (NSS) was performed according to mean arterial pressure (MAP) changes by the modified Sullivan's acute oral saline load and diuresis shrinkage test (MSAOSL-DST). Logistic regression models and restricted cubic models were used to examine the association between SSBP and hypertension. There were 554 (70.5%) salt-sensitive participants with hypertension and 412 (63.9%) salt-sensitive participants without hypertension in this study. Compared with individuals with NSS, individuals with SS had a significantly increased risk of hypertension, and the multiple-adjusted odds ratios were 2.582 with 95% confidence interval of 1.357-4.912. Furthermore, a significant linear trend was found between MAP changes and hypertension. Subgroup analyses showed significant and stronger associations between SSBP and the risk of hypertension in the older (age ≥ 55 years old), males and participants who took exercise less than 1 time per week. Our results suggest that SS is associated with an increased risk of hypertension in Tibetan population, indicating a need for clinicians dealing with SSBP to decrease the risk of hypertension.