Impact of different dietary approaches on blood pressure in hypertensive and prehypertensive patients: protocol for a systematic review and network meta-analysis

Impact of Quantity and Type of Dietary Protein on Cardiovascular Disease Risk Factors Using Standard and Network Meta-analyses of Randomized Controlled Trials

CONTEXT

Higher protein diets (HPDs) have shown favorable outcomes on weight maintenance and body-composition management; however, their protective effects against cardiovascular diseases (CVDs) remain uncertain and contentious. Furthermore, it is important to consider the influence of other macronutrients in the diet and type of dietary protein when studying HPDs, because this aspect has been overlooked in previous studies.

OBJECTIVE

We assessed the impacts of quantity and type of dietary protein on CVD risk factors.

DATA SOURCES

A database search was conducted in PubMed, Embase, CINAHL, Web of Science, and Cochrane Library and a total of 100 articles met the eligibility criteria.

DATA EXTRACTION

Extracted data from 100 articles were analyzed using standard meta-analysis, and 41 articles were also analyzed using network meta-analysis.

DATA ANALYSIS

In the standard meta-analysis, an HPD had significant favorable effects on systolic blood pressure (SBP) (mean difference [MD] = -1.51 mmHg; 95% CI: -2.77, -0.25), diastolic blood pressure (DBP) (MD = -1.08 mmHg; 95% CI: -1.81, -0.35), and flow-mediated dilation (MD = 0.78%; 95% CI: 0.09, 1.47) compared with lower protein diets. The further network meta-analysis supported that the high-protein, high-carbohydrate, low-fat diet was the most recommended diet to ensure a maximum decrease in SBP, DBP, total cholesterol (TC), and low-density-lipoprotein cholesterol (LDL-C). In comparison to animal-protein-rich diets, plant-protein-rich diets (PPRs) exhibited a significant favorable effects on improving TC (MD = -0.12 mmol/L; 95% CI: -0.19, -0.05), triglyceride (MD = -0.05 mmol/L; 95% CI: -0.09, -0.01), LDL-C (MD = -0.11 mmol/L; 95% CI: -0.18, -0.04), and high-density-lipoprotein cholesterol (MD = 0.03 mmol/L; 95% CI: 0.02, 0.04) levels.

CONCLUSION

Consumption of HPDs and PPRs supports improvements in vascular health and lipid-lipoprotein profiles, respectively. Furthermore, macronutrient composition should be carefully designed in the dietary approach to maximize the effectiveness of HPDs in improving CVD risk factors.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42022369931.

Nutritional Interventions for the Prevention of Cognitive Decline in Patients With Mild Cognitive Impairment and Alzheimer Disease: Protocol for a Network Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Mild cognitive impairment (MCI) is the stage between cognitive decline due to physiological aging and the severity of decline seen in neurodegenerative disorders like Alzheimer disease (AD), which is among the most prevalent neurodegenerative disorders characterized by cognitive impairment. People with MCI are at increased risk of developing AD. Although MCI and AD are incurable, nutritional interventions can potentially delay or prevent their onset. Consequently, effective interventions used to decelerate or alleviate the progress of cognitive impairment in older people are a significant focus in geriatric care. Given the synergistic effects of nutrition on health, assessing the effectiveness of nutritional supplements or dietary composition in preventing MCI or AD is essential for developing interventional strategies.

OBJECTIVE

Our study aims to assess the effectiveness of various nutritional interventions, including special dietary types, dietary patterns, specific foods, nutritional intake, and nutritional supplements, in preventing cognitive decline among patients diagnosed with MCI or AD. To achieve this, we will use a comprehensive approach, including network meta-analysis, pairwise meta-analysis, and systematic review of randomized controlled trials (RCTs).

METHODS

The review will follow the Population, Intervention, Comparison, Outcome (PICO) model and the PRISMA-P (Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols) guidelines. Two investigators will independently search PubMed electronically. Data extraction will follow the inclusion criteria, and data will be assessed for risk of bias using a revised tool. Additionally, evidence quality will be evaluated using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) framework. The outcomes of interest are assessing the cognitive outcomes in patients with MCI or AD. A systematic literature search will be conducted, identifying randomized controlled trials that investigate the impact of these nutritional interventions on cognitive function decline in individuals with MCI and AD. Network meta-analyses (random-effects model) and pairwise meta-analyses will then estimate the relative effectiveness of different nutritional interventions.

RESULTS

We included 51 studies, published between 1999 and 2023 (27 studies for AD and 24 studies for MCI) and involving 8420 participants. We completed data extraction for all 51 studies by December 2023. Currently, we are actively engaged in data analysis and manuscript preparation. We plan to finalize the manuscript and publish the comprehensive results by the end of 2024.

CONCLUSIONS

Our study holds significant clinical relevance given the rising prevalence of AD and the potential influence of nutritional interventions on cognitive function in individuals with MCI and AD. By investigating this relationship, our research aims to inform evidence-based decision-making in the development of prevention strategies for MCI and AD. The outcomes are expected to contribute to the establishment of reliable recommendations for MCI or AD management, providing substantial support in the field.

TRIAL REGISTRATION

PROSPERO CRD42022331173; http://tinyurl.com/3snjp7a4.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/47196.

Diet Quality, Sedentary Time, and Blood Pressure in the POUCHmoms Study

BACKGROUND

Elevated blood pressure (BP) is a major contributor to cardiovascular disease in womens; diet and sedentary time (ST) are modifiable lifestyle factors thought to influence BP.

OBJECTIVES

The aim of this study was to examine 2 diet-quality measures and ST in relation to BP among parous womens.

METHODS

This cross-sectional analysis uses data from 677 womens (age 25-55 y) enrolled in the Pregnancy Outcomes and Community Health (POUCH) Study and followed up in the POUCHmoms study 7-15 y after delivery (2011 and 2014). Follow-up measures included a food-frequency questionnaire (FFQ), self-report of ST (occupational and leisure), and systolic and diastolic blood pressure (SBP and DBP, respectively). The FFQ was used to calculate 2 diet-quality measures, Alternative Healthy Eating Index-2010 (AHEI) and Dietary Approaches to Stop Hypertension (DASH). Total ST h/wk was dichotomized at the median and labeled "low" or "high." In weighted unadjusted and adjusted regression models, BP was assessed in relation to diet scores (linear and threshold associations) and combinations of dichotomized diet-quality scores ("poor" = lowest quartile compared with "not poor" = upper 3 quartiles) and ST.

RESULTS

Higher mean SBP and DBP occurred mainly in women with a '"poor" diet-quality score (AHEI and DASH). Among womens with a "poor"-quality diet (on the basis of the AHEI score) and "high" ST, (N = 93) adjusted mean SBP and DBP were 4.5 mmHg and 4.4 mmHg higher, respectively, than that of the counterparts who did not have a poor-quality diet and had "low" ST (N = 275). Results were similar in analyses using the DASH diet score.

CONCLUSIONS

Women with poor-quality diets and more ST may need closer BP monitoring. Even modest improvements in womens' diet quality and reductions in ST might help lower their BP, but this observation needs testing in prospective studies..

Interventions for reducing blood pressure in prehypertension: A meta-analysis

Background

We aimed to address which interventions best control blood pressure (BP) and delay disease progression in prehypertension and to give recommendations for the best option following a quality rating.

Methods

A Bayesian network meta-analysis was used to assess the effect of the intervention on BP reduction, delaying hypertension progression and final outcome, with subgroup analyses for time and ethnicity. Recommendations for interventions were finally based on cumulative ranking probabilities and CINeMA.

Results

From 22,559 relevant articles, 101 eligible randomized controlled trial articles (20,176 prehypertensive subjects) were included and 30 pharmacological and non-pharmacological interventions were evaluated. Moderate-quality evidence demonstrated that angiotensin II receptor blockers, aerobic exercise (AE), and dietary approaches to stop hypertension (DASH) lowered systolic blood pressure (SBP). For lowering diastolic blood pressure (DBP), AE combined with resistance exercise (RE) or AE alone provided high quality evidence, with calcium channel blockers, lifestyle modification (LSM) combined with drug providing moderate quality evidence. LSM produced the best BP lowering effect at 12 months and beyond of intervention. In Asians, TCD bubble was moderate quality evidence for lowering SBP and RE may have had a BP lowering effect in Caucasians. No recommendation can be given for delaying the progression of hypertension and reducing mortality outcomes because of low to very low quality of evidence.

Conclusion

AE combined RE are preferentially recommended for BP control in prehypertension, followed by DASH. Long-term BP control is preferred to LSM. Asians and Caucasians add TCD bubble and RE to this list as potentially effective interventions.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022356302, identifier: CRD42022356302.

Soy intake is associated with lowering blood pressure in adults: A systematic review and meta-analysis of randomized double-blind placebo-controlled trials

BACKGROUND

Soy has several beneficial effects on cardiovascular disease (CVD); however, results of clinical trial studies are equivocal. Thus, the present study sought to discern the efficacy of soy intake on blood pressure.

METHODS

The search process was conducted in PubMed, Scopus, Web of Science, and Cochrane Library, to ascertain studies investigating the efficacy of soy intake on blood pressure in adults, published up to June 2020. A random-effects model was applied to pool mean difference and 95 % confidence interval (CI). Begg's and Egger's methods were conducted to assess publication bias.

RESULTS

Pooled effects from 17 effect sizes revealed a significant improvement in systolic blood pressure (SBP) (-1.70; -3.34 to -0.06 mmHg; I² = 45.4 %) and diastolic blood pressure (DBP) (-1.27; -2.36 to -0.19 mmHg, I² = 43.9 %) following soy consumption, in comparison with controls. Subgroup analysis demonstrated a reduction in both SBP and DBP in younger participants with lower baseline DBP and intervention durations of <16 weeks.

CONCLUSION

Our results suggest that soy intake is associated with an ameliorating effect on blood pressure in adults.

Comparison of effects of different dietary interventions on cognitive function in Alzheimer's disease: protocol for systematic review and network meta-analysis

INTRODUCTION

Alzheimer's disease (AD) is the most common neurodegenerative disease and is characterised by cognitive impairment. Non-pharmacological treatments such as diet therapy have been widely investigated in studies on AD. Given the synergistic effects of nutrients present in foods, considering overall dietary composition rather than focusing on a single nutrient may be more useful for evaluating the relationship between diet and AD cognition. The present study aimed to assess the efficacy of different dietary interventions (eg, ketogenic and Mediterranean diets) on cognitive function in patients with AD in a systematic review and pairwise and network meta-analyses of randomised controlled trials or clinical trials.

METHODS AND ANALYSIS

Two reviewers will independently conduct searches of PubMed, Cochrane Central Register of Controlled Trials, Embase, CINAHL, PsycINFO and China National Knowledge Infrastructure databases. Data will be extracted from selected studies and risk of bias will be assessed using the revised Cochrane risk-of-bias tool, and evidence quality will be assessed according to the Grading of Recommendations, Assessment, Development and Evaluation framework. The primary outcome of interest is cognitive function in patients with AD; secondary outcomes include biochemical biomarkers of AD and oxidative stress and/or inflammatory biomarkers in cerebrospinal fluid or plasma. For each outcome, random-effects pairwise and network meta-analyses will be carried out to determine the pooled relative effect of each intervention relative to every other intervention.

ETHICS AND DISSEMINATION

As this study is based solely on published literature, no ethics approval is required. The research will be published in a peer-reviewed journal.

Investigating the prevalence of hypertension and its associated risk factors in a population-based study: Fasa PERSIAN COHORT data

BACKGROUND

A high prevalence rate of hypertension (HTN) and its subsequent serious complications made this disease a major health-treatment concern in many societies. The current study aimed to investigate the prevalence of hypertension and its associated risk factors in Fasa PERSIAN COHORT in south of Iran in 2019.

METHODS

This was an analytical-cross sectional study. The study population were the individuals covered by Fasa cohort. Information of the first phase of Fasa Persian cohort in south of Iran was used in this study. Independent t test, chi-square test, analysis of variances, Pearson correlation coefficient, and multiple stepwise regression were used to analyze the obtained data. Thereafter, the data was analyzed using SPSS software version 22, and P value < 0.05 was considered as statistically significant.

RESULTS

Out of 10,111 individuals included in the study, 5546 (54.86%) subjects were women and 4565 (45.16%) other were men. The overall prevalence rate of hypertension was estimated as 46.6%. In the present study, (16/1%) of the participants were with HTN stage 1, and (17/9%) of them were with HTN stage 2. The results show that there were significant positive correlations among HTN and age, BMI, HDL, TG, BUN, ALP, smoking, physical activity, cardiovascular diseases, diabetes, and renal failure (P < 0.5).

CONCLUSIONS

Prevalence of HTN in this study population is considerable. Therefore, it is suggested that health system should program some plans to prevent hypertension's prevalence and eliminate its risk factors.

Effects of the Dietary Approaches to Stop Hypertension (DASH) on Pregnancy/Neonatal Outcomes and Maternal Glycemic Control: A Systematic Review and Meta-analysis of Randomized Clinical Trials

BACKGROUND & OBJECTIVE

No systematic review to date has appraised the impact of the Dietary Approaches to Stop Hypertension (DASH) eating plan on maternal glycemic control and pregnancy outcomes. Thus, we conducted a systematic review and meta-analysis of randomized clinical trials (RCTs) to ascertain whether the DASH diet in pregnant women ameliorates their glycemic control and neonatal outcomes when compared to standard diets.

METHODS

We performed a comprehensive systematic review and meta-analysis of RCTs on PubMed/MEDLINE, Web of Science, SCOPUS, and Embase from the inception until October 2019.

RESULTS

Six studies met the eligibility criteria and were included in the quantitative meta-analysis. The pregnant women had cardiometabolic disorders such as gestational diabetes, obesity, and hypertension. The meta-analysis suggested a significant effect of DASH diet on fasting plasma levels of glucose (WMD = -6.239 mg/dl; 95% CI: -11.915, -0.563, p = 0.031), but not for the homeostasis model assessment of insulin resistance (WMD = -1.038; 95% CI: -2.704, 0.627, p = 0.22). Following the DASH diet during pregnancy decreased the risk of gestational preeclampsia (RR = 0.667; 95% CI: 0.451, 0.987, p = 0.043), macrosomia (birth weight >4000 g) (RR = 0.294; 95% CI: 0.120, 0.721, p = 0.043), and large for gestational age (RR = 0.452; 95% CI: 0.211, 0.969, p = 0.041). Consuming DASH diet during pregnancy neither increased nor decreased the risk of cesarean section, polyhydramnios, preterm birth (<37 weeks), and small for gestational age. The mean newborn head circumference (cm) (WMD = -0.807; 95% CI: -1.283, -0.331, p = 0.001) and ponderal index (kg/m³) (RR = -0.396; 95% CI: -0.441, -0.350, p = 0.000) in the group receiving the DASH diet were lower than in the control group.

CONCLUSION

The adherence of pregnant women with cardiometabolic disorders to DASH eating pattern has a significant effect on decreasing fasting plasma glucose levels, ponderal index, incidence of preeclampsia, fetal macrosomia, large for gestational age, and newborn head circumference.

Predictive Performance of Pender's Health Promotion Model for Hypertension Control in Iranian Patients

Objective

The main aim of this study was to investigate predictive factors of adherence to the hypertension control therapeutic and lifestyle recommendations in a sample of Iranian patients based on the constructs of Pender’s health promotion model.

Patients and Methods

The cross-sectional study was performed on the 380 hypertensive patients who were referred to the health centers, the emergency and internal diseases departments of the Bagheralolom Hospital, and the cardiologists’ offices in the city of Ahar, North West of Iran. Data were collected using a researcher designed questionnaire based on the Pender’s health promotion model. The Pearson correlation test, multivariate linear regression, and independent t-test were used for data analysis.

Results

Mean age of the recruited patients was 52.94 (SD=12.8). Perceived benefits, perceived barriers, situational influences, and interpersonal influences (adjusted R²= 0.525) explained 52.5% of the observed variation in adherence to hypertension control recommendations.

Conclusion

Successful hypertension control in patients with chronic morbidity need to be based on sound data about major determinants of the relevant health/illness behaviors. The study findings revealed that the Pender’s health promotion model could be applicable as a theoretical framework to identify major determinants of adherence to hypertension control recommendations. Future cross-cultural validation of the study findings in more representative and larger sample sizes could add to the legitimacy of the evidence surrounding self-care practices in hypertensive patients.

The efficacy of the Dietary Approaches to Stop Hypertension diet with respect to improving pregnancy outcomes in women with hypertensive disorders

BACKGROUND

The DASH (Dietary Approaches to Stop Hypertension) diet serves as a dietary pattern for the prevention and control of hypertension. The present study aimed to investigate whether the DASH diet can improve the outcomes of pregnancy with gestational hypertension (GH) and chronic hypertension.

METHODS

The current randomised controlled clinical trial was performed in 85 pregnant women diagnosed with GH and chronic hypertension between July 2015 and December 2017. The women were categorised into a control group (41 cases) and a DASH group (44 cases). Participants were followed until delivery. The clinical outcomes of mothers included gestational weeks of birth, delivery mode, postpartum haemorrhage and GH, as well as the incidence of pre-eclampsia during the second and third trimesters. Newborn measurements were collected by evaluating prematurity, birth weight, body length and neonatal Apgar score.

RESULTS

The incidence of pre-eclampsia, prematurity and low birth weight in the DASH group was lower than that in the control group (P < 0.05). Significant differences were also observed in gestational age at delivery and the newborn body length between the two groups (P < 0.05). We failed to find a significant difference in changes of delivery mode, postpartum haemorrhage, postpartum GH, mean birth weight and Apgar score (P > 0.05) between the two diets.

CONCLUSIONS

A DASH diet might comprise a potential strategy for improving the clinical outcomes in pregnant women with GH and chronic hypertension. Future robust clinical trials are warranted to corroborate these findings.