The relationship between dietary salt intake and ambulatory blood pressure variability in non-diabetic hypertensive patients

Association between short-term blood pressure variability and target organ damage in non-dialysis patients with chronic kidney disease

BACKGROUND

It is unclear whether short-term blood pressure variability (BPV) is associated with target organ damage in patients with non-dialysis chronic kidney disease (CKD).

METHODS

A cross-sectional, single-center study was conducted among 3442 non-dialysis CKD patients hospitalized in the department of Nephrology of the Fifth Affiliated Hospital of Sun Yat-sen University from November 2017 to July 2022 and collected the demographic, laboratory, clinic blood pressure, ambulatory blood pressure data, and short-term BPV assessed by the weighted standard deviation (wSD) derived from ambulatory blood pressure monitoring (ABPM). Multivariate logistic analyses were used to evaluate the independent effects between short-term BPV and subclinical target organ damage, including left ventricular hypertrophy (LVH), abnormal carotid intima-media thickness (CIMT), low estimated glomerular filtration rate (eGFR), and albuminuria.

RESULTS

The average age of the participants was 47.53 ± 14.06 years and 56% of participants were male. The baseline eGFR was 69 mL/min/1.73 m2. Based on the tertile distribution of wSD according to equal numbers, patients were divided into three categories with T1(< 9.66 mmHg), T2(9.66-12.23 mmHg), and T3(> 12.23 mmHg) of SBPV; T1(< 8.17 mmHg), T2(8.17-9.93 mmHg), and T3(> 9.93 mmHg) of DBPV. The participants with the higher wSD group had a higher prevalence of target organ damage than their counterparts (P-trend < 0.05). An increasing trend in short-term variability was present with advancing CKD stages (P-trend < 0.001). Multivariate logistic analyses results showed that the odds ratio (OR) of SBP wSD was (1.07 [1.03,1.11], P < 0.001) for LVH, (1.04 [1.01,1.07, P = 0.029) for abnormal CIMT, (1.05 [1.02,1.08], P = 0.002) for low eGFR, and (1.06 [1.02,1.09], P = 0.002) for albuminuria; The OR of DBP wSD was (1.07 [1.02,1.12], P = 0.005) for LVH, (1.05 [1.01,1.09], P = 0.028) for abnormal CIMT, (1.05 [1.01,1.09], P = 0.022) for low eGFR, and (1.05 [1.01,1.10], P = 0.025) for albuminuria when adjusted for confounding factors and mean BP.

CONCLUSIONS

In conclusion, short-term BPV is associated with target organ damage, and irresponsible of average blood pressure levels, in Chinese non-dialysis CKD participants.

Age differences in the impact of dietary salt on metabolism, blood pressure and cognitive function in male rats

The influence of salt consumption on physiological processes, especially blood pressure (BP), metabolism, and cognition, remains a topical concern. While guidelines endorse reduced salt diets, there are gaps in understanding the age-specific implications and challenges in adherence. The present study delved into the differential effects of salt intake on young adult and aged male rats over a 12-week period, using control, low-, and high-salt diets. Key metrics, such as BP, cognition, and general parameters, were monitored. Our findings revealed significant age-dependent effects of salt intake on survival rates, body weight, blood sodium, blood glucose, blood lipids, BP, heart rates, and cognition. Notably, young adult rats did not show significant sodium level changes on a high-salt diet, whereas aged rats experienced increased sodium levels even on a normal salt diet. Blood glucose levels decreased significantly in aged rats on a high-salt diet but remained stable in young adults. Aged rats had the highest survival rates on low-salt diets. Low-salt diets led to reduced BP in both age groups, more significantly in young adults. Young adult rats displayed increased BP variability on both high- and low-salt diets, while a decrease in BP variability was exclusive to aged rats on a low-salt diet. There were significant differences across age groups in short-term memory, but not in long-term memory. The study provides a nuanced understanding of the age-dependent physiological effects of salt intake, suggesting the necessity of age-specific guidelines for public health.

Sex influences blood pressure but not blood pressure variability in response to dietary sodium and potassium in salt-resistant adults

Dietary sodium and potassium have been shown to affect blood pressure (BP) but their influence on BP variability (BPV) is less studied as is the influence of sex. The aim of this study was to compare 24 h BP and short-term BPV in response to varying dietary levels of sodium and potassium in healthy non-obese normotensive salt-resistant adults. We hypothesized that high sodium would increase short-term BP and BPV while the addition of high potassium would counteract this increase. Furthermore, we hypothesized that women would experience greater increases in BPV under high sodium conditions compared to men while potassium would attenuate this response. Thirty-seven participants (17 M/20 W; 27 ± 5 years old; BMI 24.3 ± 3 kg/m2) completed seven days each of the following randomized diets: moderate potassium/low sodium (MK/LS), moderate potassium/high sodium (MK/HS) and high potassium/high sodium (HK/HS). BP and short-term BPV were assessed using 24 h ambulatory BP monitoring starting on day 6. BPV was calculated using the average real variability (ARV) index. Twenty-four hour, daytime, and nighttime systolic BP (SBP) were lower in women compared to men regardless of diet. However, 24 h and daytime SBP were lowered in women on the HK/HS diet compared to the MK/HS diet. There were no significant effects of diet or sex for 24 h, daytime or nighttime SBP ARV. However, men exhibited a higher 24 hDBP ARV than women regardless of diet. In conclusion, a high potassium diet lowered BP under high sodium conditions in women alone while men exhibited higher short-term BPV that was not influenced by diet.

Urinary Sodium Excretion and Salt Intake Are Not Associated With Blood Pressure Variability in a White General Population

Background Salt restriction may lower blood pressure variability (BPV), but previous studies have shown inconsistent results. Therefore, we investigated in an observational study and intervention trial whether urinary sodium excretion and salt intake are associated with 24-hour BPV. Methods and Results We used data from the cross-sectional population-based Maastricht Study (n=2652; 60±8 years; 52% men) and from a randomized crossover trial (n=40; 49±11 years; 33% men). In the observational study, we measured 24-hour urinary sodium excretion and 24-hour BPV and performed linear regression adjusted for age, sex, mean blood pressure, lifestyle, and cardiovascular risk factors. In the intervention study, participants adhered to a 7-day low- and high-salt diet (50 and 250 mmol NaCl/24 h) with a washout period of 14 days, 24-hour BPV was measured during each diet. We used linear mixed models adjusted for order of diet, mean blood pressure, and body mass index. In the observational study, 24-hour urinary sodium excretion was not associated with 24-hour systolic or diastolic BPV (β, per 1 g/24 h urinary sodium excretion: 0.05 mm Hg [95% CI, -0.02 to 0.11] and 0.04 mm Hg [95% CI, -0.01 to 0.09], respectively). In the intervention trial, mean difference in 24-hour systolic and diastolic BPV between the low- and high-salt diet was not statistically significantly different (0.62 mm Hg [95% CI, -0.10 to 1.35] and 0.04 mm Hg [95% CI, -0.54 to 0.63], respectively). Conclusions Urinary sodium excretion and salt intake are not independently associated with 24-hour BPV. These findings suggest that salt restriction is not an effective strategy to lower BPV in the White general population. Registration URL: https://clinicaltrials.gov/ct2/show/NCT02068781.

High dietary salt intake increases urinary NGAL excretion and creatinine clearance in healthy young adults

In rodents and older patients with elevated blood pressure (BP), high dietary sodium increases excretion of biomarkers of kidney injury, but it is unclear whether this effect occurs in healthy young adults. The purpose of this study was to determine whether short-term high dietary salt increases urinary excretion of the kidney injury biomarkers neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule-1 (KIM-1) in healthy young adults. Twenty participants participated in a double-blind, placebo-controlled, randomized crossover study. For 10 days each, participants were asked to consume salt (3,900 mg sodium) or placebo capsules. We measured BP during each visit, obtained 24-h urine samples for measurements of electrolytes, NGAL, and KIM-1, and assessed creatinine clearance. Compared with placebo, salt loading increased daily urinary sodium excretion (placebo: 130.3 ± 62.4 mmol/24 h vs. salt: 287.2 ± 72.0 mmol/24 h, P < 0.01). There was no difference in mean arterial BP (placebo: 77 ± 7 mmHg vs. salt: 77 ± 6 mmHg, P = 0.83) between conditions. However, salt loading increased the urinary NGAL excretion rate (placebo: 59.8 ± 44.4 ng/min vs. salt: 80.8 ± 49.5 ng/min, P < 0.01) and increased creatinine clearance (placebo: 110.5 ± 32.9 mL/min vs. salt: 145.0 ± 24.9 mL/min, P < 0.01). Urinary KIM-1 excretion was not different between conditions. In conclusion, in healthy young adults 10 days of dietary salt loading increased creatinine clearance and increased urinary excretion of the kidney injury biomarker marker NGAL but not KIM-1.NEW & NOTEWORTHY In healthy young adults, 10 days of dietary salt loading increased creatinine clearance and increased urinary excretion of the kidney injury biomarker marker neutrophil gelatinase-associated lipocalin despite no change in resting blood pressure.

Salt Consumption and Blood Pressure in Rural Hypertensive Participants: A Community Filed Trial

Purpose. Hypertension is a major cause of morbidity and mortality in the world. This study aimed to evaluate an intervention based on the Health Belief Model regarding the whole family’s salt consumption and blood pressure among hypertensive patients in rural areas in Iran. Methods. This clinical multicenter trial (clinical and community) with a control and an intervention group was conducted on the residents of 14 villages covered by 14 health houses. Totally, 200 hypertensive patients (n = 100 in each group) were selected via multistage random sampling. The intervention included a two-day workshop on blood pressure and reducing salt consumption based on HBM structures for health personnel and an eight-session workshop on how to reduce salt intake and blood pressure for mothers who were responsible for the families’ diets. Participants completed the questionnaires before and immediately after the intervention. Results. Compared to the control group, in the intervention group, a significant reduction was observed in salt consumption by the families (urine sodium and creatinine reduced by 35 mEq/l and 7.5 mg/dL, respectively). The results also revealed a significant decrease in blood pressure in the intervention group. Conclusion. The results showed that the mothers’ model-based education could effectively improve the diet of the whole family members and, as a result, reduce the associated diseases. The main advantage of this study was the involvement of the rural health personnel, which helped run longer and larger-scale health-promotion programs in the communities.

Dietary sodium and health: How much is too much for those with orthostatic disorders?

High dietary salt (NaCl) increases blood pressure (BP) and can adversely impact multiple target organs including the vasculature, heart, kidneys, brain, autonomic nervous system, skin, eyes, and bone. However, patients with orthostatic disorders are told to increase their NaCl intake to help alleviate symptoms. While there is evidence to support the short-term benefits of increasing NaCl intake in these patients, there are few studies assessing the benefits and side effects of long-term high dietary NaCl. The evidence reviewed suggests that high NaCl can adversely impact multiple target organs, often independent of BP. However, few of these studies have been performed in patients with orthostatic disorders. We conclude that the recommendation to increase dietary NaCl in patients with orthostatic disorders should be done with care, keeping in mind the adverse impact on dietary NaCl in people without orthostatic disorders. Modest, rather than robust, increases in NaCl intake may be sufficient to alleviate symptoms but also minimize any long-term negative effects.

Association of Urinary Potassium Excretion with Blood Pressure Variability and Cardiovascular Outcomes in Patients with Pre-Dialysis Chronic Kidney Disease

Dietary potassium intake is a dilemma in patients with chronic kidney disease (CKD). We investigated the association of urine potassium excretion, a surrogate for dietary potassium intake, with blood pressure variability (BPV) and cardiovascular (CV) outcomes in patients with pre-dialysis CKD. A total of 1860 participants from a cohort of pre-dialysis CKD (KNOW-CKD) patients were divided into the quartiles by spot urine potassium-to-creatinine ratio. The first quartile (26.423 ± 5.731 mmol/gCr) was defined as low urine potassium excretion. Multivariate linear regression analyses revealed an independent association of low urine potassium excretion with high BPV (adjusted β coefficient 1.163, 95% confidence interval 0.424 to 1.901). Cox regression analyses demonstrated that, compared to high urine potassium excretion, low urine potassium excretion is associated with increased risk of CV events (adjusted hazard ratio 2.502, 95% confidence interval 1.162 to 5.387) but not with all-cause mortality. In conclusion, low urine potassium excretion is associated with high BPV and increased risk of CV events in patients with pre-dialysis CKD. The restriction of dietary potassium intake should be individualized in patients with pre-dialysis CKD.

Nutritional and Chemical-Physical Characterization of Fresh Pasta Gnocchi Prepared with Sea Water as New Active Ingredient

This study shows the chemical-physical and nutritional results obtained using food-grade sea water for the preparation of fresh pasta Gnocchi with respect to those prepared with tap water. Gnocchi obtained by mixing the flour with seawater (GSW) were compared with traditional Gnocchi made with tap water (GTW). The contents of sodium chloride, macro and micro elements, volatile molecules profile, thermal properties, and morphological analysis were investigated in both Gnocchi types. The analysis of chlorides showed that the samples prepared with sea water had a significantly lower NaCl content after cooking in comparison with those prepared with tap water. These results were also confirmed by the inductively coupled plasma (ICP) analysis for sodium content. The profiles of the volatile molecules acquired by gas chromatography-mass spectrometry (GC-MS) evidenced significant differences between the groups of aromatic molecules of the two typologies of samples. Morphological analysis evidenced that both raw and cooked GSW Gnocchi were structurally tightened whereas GTW Gnocchi showed a labile and weak macromolecular network. In addition, GSW Gnocchi was more thermally stable than GTW Gnocchi, as evidenced by thermogravimetric analysis (TGA).

Preliminary Experiment on the Effect of 18% Substitute Salt on Home Blood Pressure Variability in Hypertensives

At present, the effect of substitute salt in reducing sodium intake and blood pressure is relatively clear. The present study is a phase I clinical trial involving 43 hypertensives in which the effect of 18% sodium substitute salt on the home blood pressure variability (BPV) was observed for 8 weeks with weekly follow-up. Finally, 4 patients were lost, and 39 patients completed the intervention and were included in the analysis. Daily home blood pressure and weekly adverse events were collected. The systolic blood pressure (SBP) in the morning (-10.0 mmHg, 95% CI: -16.5 to -3.5, P = 0.003), SBP at night (-10.2 mmHg, 95% CI: -16.1 to -4.3, P = 0.001), and diastolic blood pressure (DBP) at night (-4.0 mmHg, 95% CI: -7.1 to -0.8, P = 0.014) decreased significantly. Also, there was no statistically significant change in morning (F = 1.137, P = 0.352) and night diastolic (F = 0.344, P = 0.481) BPV and morning systolic BPV (F = 0.663, P = 0.930) over time during the intervention period, except for that night systolic BPV had a downward trend (F = 2.778, P = 0.016) and had decreased 2.04 mmHg (95% CI: 0.84 to 3.23, P = 0.001) after intervention. The use of 18% of the substitute salt did not increase BPV during the intervention and even may decrease it, which indicates its control effects on blood pressure. This study is the first one to observe the effect of 18% sodium substitute salt on the home blood pressure variability, providing a basis for further experiments.

Do children with solitary or hypofunctioning kidney have the same prevalence for masked hypertension?

BACKGROUND

Having a low nephron number is a well-known risk factor for hypertension. There is an inverse relationship between the filtration surface area and systemic hypertension. A significant percentage of masked hypertension can be detected in children with nephron loss by ambulatory blood pressure monitoring (ABPM).

METHODS

We prospectively investigated ABPM results of children having reduced kidney mass with normal office blood pressures (BPs) and kidney function. Forty-three children with congenital solitary kidney (group 1), 11 children with acquired solitary kidney (group 2), and 76 children with hypofunctioning kidney (group 3) were compared with age, gender, and BMI-matched healthy control group (group 4). The dietary salt intake of 76 patients was evaluated as salt equivalent (g/day). The primary endpoint was change from baseline in mean 24-h ABPM variables and the proportion of patients with masked hypertension when assessed by ABPM.

RESULTS

The masked hypertension ratio of all patients was 12.3% when assessed with ABPM. Night hypertension was significantly higher in all patient groups than in the control group (p = 0.01). Diastolic BP loads of groups 1 and 3 were higher than in controls (p = 0.024). Systolic BP loads were higher only in group 1 than in the control group (p = 0.003). The dietary salt equivalent of patients in group 1 correlated positively with 24-h SBP and mean arterial pressure (MAP) values. Patients with excessive dietary salt intake in group 1 had a significantly higher diastolic BP load than those without excessive salt intake in group 1 (p = 0.002).

CONCLUSIONS

Masked hypertension can be seen in children with a solitary kidney or when one of the kidneys is hypofunctioning. Systolic BP loads are higher in children with congenital solitary kidney, and salt intake correlates with systolic BP profiles especially in those. Our results suggest that being born with a congenital solitary kidney increases predisposition to hypertension and salt sensitivity.

Impact of dietary intake of sodium and potassium on short-term blood pressure variability

BACKGROUND

Dietary Approaches to Stop Hypertension (DASH)-Sodium trial showed that dietary sodium and potassium affect blood pressure (BP). We aimed to investigate whether dietary sodium and potassium affect short-term BP variability (BPV) in addition to BP.

METHODS

A total of 343 participants from the DASH-Sodium trial (age 48.4 ± 9.7, 42.5% men) and 323 individuals from the Jackson Heart Study (JHS) (age 56.7 ± 11.2, 30.7% men) with satisfactory ambulatory BP monitoring records and 24-h urine collection were included. Average real variability (ARV) was calculated as a measure of short-term BPV.

RESULTS

By estimating dietary intake from urinary excretion, we observed that higher urinary sodium-to-potassium ratio was significantly associated with higher diastolic ARV in both studies. Among the DASH-Sodium trial, potassium-rich DASH diet alone had insignificant effect on both systolic (-0.1 ± 1.7 mmHg, P = 0.343) or diastolic ARV (-0.2 ± 1.5 mmHg, P = 0.164), whereas combined DASH diet and low sodium intake significantly reduced both systolic (8.5 ± 1.6 vs. 8.9 ± 1.7 mmHg, P = 0.032) and diastolic ARV (7.5 ± 1.5 vs. 7.8 ± 1.6 mmHg, P = 0.025) as compared with control diet and high sodium intake. As the reduction of systolic ARV was majorly derived from the change of mean SBP, diastolic ARV was significantly determined by urinary sodium-to-potassium ratio (β coefficient ± standard error: 0.012 ± 0.004; P = 0.006) after adjusting for age, sex, smoking, mean DBP, BMI, and race.

CONCLUSION

Dietary sodium and potassium can jointly modulate short-term BPV in addition to BP. Combined DASH diet and low sodium intake may reduce systolic and diastolic ARV via different mechanisms.

Differences of sodium consumption pattern hypertension sufferer in coastal and highland communities in Wakatobi islands

Available data indicate that food sodium (such as salt) is directly related to blood pressure (BP). The research aims to look at the different sodium consumption patterns of hypertension sufferers in two different coastal areas and highland areas in the Wakatobi Islands. The type of research is observational analytic research using a cross-sectional design. This study has been carried out in the District of Wangi-Wangi, especially in the MolaSamaturu villages and Waginopo Village in October 2019. The number of research samples is 100 people (50 respondents in Mola Samaturu Village and 50 people in Waginopo Village). The results showed the differences between sodium consumption patterns in hypertensive sufferers in Mola Samaturu Village and Waginopo Village with a p-value = 0,000 <α 0.05. Sodium consumption patterns in coastal communities are higher than in highlands community.

Association between dietary sodium intake and blood pressure variability in Chinese patients with hypertension

Background

The association between dietary sodium intake and blood pressure variability (BPV) in hypertensive patients remains unclear. The objective of this study was to demonstrate whether dietary sodium intake is a predictor of elevated BPV in Chinese patients with hypertension.

Methods

A total of 235 patients with essential hypertension were enrolled in the Department of Cardiology, Chinese People's Liberation Army (PLA) General Hospital in 2018 to 2019, all of whom underwent 24-h ambulatory blood pressure monitoring. BPV was calculated as the standard deviation (SD), coefficient of variation (CV), variation independent of mean (VIM) of blood pressure measurements, respectively, and divided into diurnal systolic BPV (SBPV), diurnal diastolic BPV (DBPV), nocturnal SBPV, and nocturnal DBPV. 24-h urine samples were collected to measure 24-h urine sodium excretion, which represents dietary sodium intake. The relationship between dietary sodium intake and BPV was analyzed by using Spearman correlations and multiple linear regression analysis.

Results

Nocturnal SBPV-SD, CV, VIM, and nocturnal DBPV-SD in the high urine sodium excretion group were significantly higher than those in the medium and low urine sodium excretion groups, whereas diurnal SBPV-SD, CV, VIM, diurnal DBPV-SD, CV, VIM, and nocturnal DBPV-CV, VIM were not. Using the Spearman correlation analysis, we found a linear correlation between 24-h urine sodium excretion and nocturnal SBPV-SD, CV, VIM (SD, r = 0.22, P = 0.001; CV, r = 0.17, P = 0.009; VIM, r = 0.16, P = 0.020), nocturnal DBPV-SD (r = 0.21, P = 0.001), respectively. After further adjusting for confounding factors by multiple linear regression, the positive correlations remained between 24-h urine sodium excretion and nocturnal SBPV-SD, CV, VIM (SD, β = 0.224, P < 0.001; CV, β = 0.211, P = 0.001; VIM, β = 0.213, P = 0.001), nocturnal DBPV (SD, β = 0.215, P = 0.001), respectively.

Conclusions

Dietary sodium intake is associated with nocturnal SBPV in Chinese patients with hypertension.

Dietary Sodium Intake and Health Indicators: A Systematic Review of Published Literature between January 2015 and December 2019

As the science surrounding population sodium reduction evolves, monitoring and evaluating new studies on intake and health can help increase our understanding of the associated benefits and risks. Here we describe a systematic review of recent studies on sodium intake and health, examine the risk of bias (ROB) of selected studies, and provide direction for future research. Seven online databases were searched monthly from January 2015 to December 2019. We selected human studies that met specified population, intervention, comparison, outcome, time, setting/study design (PICOTS) criteria and abstracted attributes related to the study population, design, intervention, exposure, and outcomes, and evaluated ROB for the subset of studies on sodium intake and cardiovascular disease risks or indicators. Of 41,601 abstracts reviewed, 231 studies were identified that met the PICOTS criteria and ROB was assessed for 54 studies. One hundred and fifty-seven (68%) studies were observational and 161 (70%) focused on the general population. Five types of sodium interventions and a variety of urinary and dietary measurement methods were used to establish and quantify sodium intake. Five observational studies used multiple 24-h urine collections to assess sodium intake. Evidence mainly focused on cardiovascular-related indicators (48%) but encompassed an assortment of outcomes. Studies varied in ROB domains and 87% of studies evaluated were missing information on ≥1 domains. Two or more studies on each of 12 outcomes (e.g., cognition) not previously included in systematic reviews and 9 new studies at low ROB suggest the need for ongoing or updated systematic reviews of evidence on sodium intake and health. Summarizing evidence from assessments on sodium and health outcomes was limited by the various methods used to measure sodium intake and outcomes, as well as lack of details related to study design and conduct. In line with research recommendations identified by the National Academies of Science, future research is needed to identify and standardize methods for measuring sodium intake.

Relationship between saline infusion and blood pressure variability in non-critically patients with hypertension: A retrospective study

Saline is a commonly used intravenous solvent, however, its excessive infusion may increase drug-induced sodium intake. To investigate the effects of saline infusion on blood pressure variability (BPV) in patients with hypertension, a retrospective study was performed in 1010 patients with hypertension. The patients who received saline infusion before surgery for continuous 3 to 5 days were divided into 2 groups according to the saline infusion volume during the hospitalization, which are >500 mL per day group and <500 mL per day group. The overall incidence of abnormal BPV was 11.58%. As for the incidence of abnormal BPV in the <500 mL per day group with 698 patients was 9.17%, while that in the >500 mL per day group with 312 patients was as high as 16.99%. Additionally, >500 mL of daily saline infusion for continuous 3 to 5 days (P for trend = .004, odds ratio [OR] = 1.911, 95% confidence interval [CI] for OR 1.226-2.977), medical history of diabetes mellitus (P < .001, OR = 4.856, 95% CI for OR 3.118-7.563) and cardiovascular diseases (P < .001, OR = 2.498, 95% CI for OR 1.549-4.029) may be risk factors of abnormal BPV; while anti-hypertensive therapy with diuretics (P < .001, OR = 0.055, 95% CI for OR 0.024-0.125) may be the protective factor. Our study suggests that >500 mL of daily saline infusion for continuous 3 to 5 days may have disadvantages in the blood pressure control for hypertensive patients, especially for the patients with diabetes mellitus and cardiovascular diseases.

Hydration status and blood pressure variability in primary hypertensive patients

BACKGROUND

Increased blood pressure variability (BPV) is associated with higher cardiovascular risk. The association between BPV and fluid status in hypertensive patients has not been investigated so far. The aim of the present study was to determine the contribution of fluid balance to BPV and impact on endothelial and cardiac functions among primary hypertensive patients.

METHODS

This is a prospective interventional study conducted in primary hypertensive patients with one-year follow-up. Volume status measurements by a body composition monitor, ambulatory blood pressure (BP) monitoring, echocardiographic and carotid intima-media thickness (CIMT) measurements were performed at enrollment and at twelfth. Patients in one of the two groups were kept negative hydrated during trial with diuretic treatment. Patients in other group were positively hydrated (hypervolemic) at enrollment, antihypertensive drugs other than diuretics (vasodilator agents) were added or intensified according to the BP monitoring. Average real variability (ARV) index was used for establishing the prognostic significance of BPV.

RESULTS

The study population consisted of 50 patients with a mean age of 54.5±8.8 years. At the end of one-year follow-up, patients in negative hydrated group were found to have significantly lower BP, CIMT, left ventricle mass index (LVMI) and systolic and diastolic ARV. More weight gain and higher systolic BP were major risk factors of high systolic ARV. Patients who have improvement in CIMT and LVMI were considered as target organ damage (TOD) recovery present. In negatively hydrated group, TOD significantly reduced during trial. In patients who have TOD recovery, BPV significantly more reduced like systolic and diastolic BP. Significant risk factors associated with the presence of TOD were 24h systolic BP and daytime and night time diastolic ARV and night time diastolic BP.

CONCLUSION

Addition of diuretic to established treatment or intensified diuretic treatment and keeping patients in negative hydration status resulted in reduction in BPV at twelfth month of follow-up. More weight gain and higher systolic BP are major risk factors of high systolic ARV, but not hypervolemia. BPV, especially diastolic ARV, was significantly associated with TOD.

The Impact of High Dietary Sodium Consumption on Blood Pressure Variability in Healthy, Young Adults

BACKGROUND

High sodium (Na+) intake augments blood pressure variability (BPV) in normotensive rodents, without changes in resting blood pressure (BP). Augmented BPV is associated with end-organ damage and cardiovascular morbidity. It is unknown if changes in dietary Na+ influence BPV in humans. We tested the hypothesis that high Na+ feeding would augment BPV in healthy adults.

METHODS

Twenty-one participants (10 F/11 M; 26 ± 5 years; BP: 113 ± 11/62 ± 7 mm Hg) underwent a randomized, controlled feeding study that consisted of 10 days of low (2.6 g/day), medium (6.0 g/day), and high (18.0 g/day) salt diets. On the ninth day of each diet, 24-h urine samples were collected and BPV was calculated from 24-h ambulatory BP monitoring. On the tenth day, in-laboratory beat-to-beat BPV was calculated during 10 min of rest. Serum electrolytes were assessed. We calculated average real variability (ARV) and standard deviation (SD) as metrics of BPV. As a secondary analysis, we calculated central BPV from the 24-h ambulatory BP monitoring.

RESULTS

24-h urinary Na+ excretion (low = 41 ± 24, medium = 97 ± 43, high = 265 ± 92 mmol/24 h, P < 0.01) and serum Na+ (low = 140.0 ± 2.1, medium = 140.7 ± 2.7, high = 141.7 ± 2.5 mmol/l, P = 0.009) increased with greater salt intake. 24-h ambulatory ARV (systolic BP ARV: low = 9.5 ± 1.7, medium = 9.5 ± 1.2, high = 10.0 ± 1.9 mm Hg, P = 0.37) and beat-to-beat ARV (systolic BP ARV: low = 2.1 ± 0.6, medium = 2.0 ± 0.4, high = 2.2 ± 0.8 mm Hg, P = 0.46) were not different. 24-h ambulatory SD (systolic BP: P = 0.29) and beat-to-beat SD (systolic BP: P = 0.47) were not different. There was a trend for a main effect of the diet (P = 0.08) for 24-h ambulatory central systolic BPV.

CONCLUSIONS

Ten days of high sodium feeding does not augment peripheral BPV in healthy, adults.

CLINICAL TRIALS REGISTRATION

NCT02881515.

The effect of intermittent fasting on blood pressure variability in patients with newly diagnosed hypertension or prehypertension

Intermittent fasting is a phenomenon which can be observed in most humans. The effect of intermittent fasting on blood pressure variability (BPV) has not previously been investigated. The purpose of this study was to assess the effect of fasting on blood pressure (BP) (with office, home, central, and ambulatory blood pressure monitoring [ABPM]) and on BPV. Sixty individuals were included in the study. Office, home, ABPM, and central BP measurements were performed before and during intermittent fasting. Standard deviation and coefficient variation were used for office and home BPV measurement, while the smoothness index was used to calculate ABPM variability. Patients' BP and BPV values before and during intermittent fasting were then compared. Intermittent fasting resulted in a significant decrease in office BP values and ABPM measurements but caused no significant change in home and central BP measurements. Twenty-four hour urinary sodium excretion decreased. Smoothness values obtained from ABPM measurements were low; in other words, BPV was greater. BPV was higher in patients who woke up to eat before sunrise, but BPV was low in patients with high body mass index. Intermittent fasting produced a significant decrease in BP values in terms of office and ABPM measurements in this study but caused no significant change in central BP and home measurements. We also identified an increase in BPV during intermittent fasting, particularly in patients who rose before sunrise.