The impact of angiotensin II receptor blockade and the DASH diet on markers of endogenous fibrinolysis

Effects of the DASH diet and losartan on serum urate among adults with hypertension: Results of a randomized trial

Serum urate is a risk factor for hypertension and gout. The DASH diet and losartan independently lower blood pressure (BP); however, their effects on serum urate are understudied. We performed a post-hoc analysis of the DASH-losartan trial, which randomized participants with hypertension in parallel fashion to the DASH diet or a standard American diet (control) and in crossover fashion to 4-week losartan or placebo. Serum urate was measured at baseline and after each 4-week period. Diets were designed to maintain weight constant. We examined the effects of DASH (vs control) and/or losartan (vs placebo) on serum urate, overall and among those with baseline serum urate ≥6 mg/dL, using generalized estimating equations. Of 55 participants (mean age 52 years, 58% women, 64% Black), mean (±SD) baseline ambulatory SBP/DBP was 146±12/91±9 and mean (±SD) serum urate was 5.2±1.2 mg/dL. The DASH diet did not significantly reduce urate levels overall (mean difference -0.05 mg/dL; 95%CI: -0.39, 0.28), but did decrease levels among participants with baseline hyperuricemia (-0.33 mg/dL; 95%CI: -0.87, 0.21; P-interaction=0.007 across hyperuricemia groups). Losartan significantly decreased serum urate (-0.23 mg/dL; 95%CI: -0.40, -0.05) with greater effects on serum urate among adults <60 years old versus adults ≥60 years old (-0.33 mg/dL vs 0.16 mg/dL, P interaction = 0.003). In summary, the DASH diet significantly decreased serum urate among participants with higher urate at baseline, while losartan significantly reduced serum urate, especially among younger adults. Future research should examine the effects of these interventions in patients with hyperuricemia or gout.

A Systematic Review of Literature on the Representation of Racial and Ethnic Minority Groups in Clinical Nutrition Interventions

The racial and ethnic disparities in diet-related chronic diseases are major concerns. This systematic review examines the extent to which diet-induced changes in health outcomes, such as cardiometabolic, inflammation, cancer, bone health, and kidney function outcomes, etc., have been reported and discussed by race or ethnicity in randomized trials with 2 or more diet arms that recruited both minority and non-Hispanic White groups. Databases (i.e., PubMed, Cochrane Library, and Web of Science) were searched up to August 2021. Thirty-four studies that discussed effects of defined dietary interventions on health outcomes by racial or ethnic minority group compared with non-Hispanic Whites were included in the systematic review (PROSPERO registration number: CRD42021229256). Acute trials and those with 1 diet arm that accounted for race or ethnicity in their analyses and studies that focused on a single racial or ethnic group were discussed separately. Most studies were conducted in Black compared with White adults testing effects of energy restriction, macronutrient modification, sodium reduction, or variations of the Dietary Approaches to Stop Hypertension (DASH) diet on cardiometabolic outcomes. There was limited focus on other minority groups. Evidence suggests greater blood pressure reduction for Black adults compared with Whites particularly with DASH (or similar) diets. Overall, there was limited consideration for group-specific eating patterns and diet acceptability. Overall risk of bias was low. With emerging precision nutrition initiatives that aim to optimize metabolic responses in population subgroups through tailored approaches, it is imperative to ensure adequate representation of racial and ethnic subgroups for addressing health disparities. Factors that help explain variability in responses such as socioecological context should be included and adequately powered. Given the racial and ethnic disparities in chronic diseases, studying the adoption, maintenance, and effectiveness of dietary interventions on health outcomes among different groups is critical for developing approaches that can mitigate diet-related health disparities.

The relationship between Dietary approaches to stop hypertension diet adherence and inflammatory factors and insulin resistance in overweight and obese women: A cross-sectional study

BACKGROUND

Although there is abundant evidence for an association between dietary pattern, weight, and other related factors, such as homeostatic model assessment for insulin resistance (HOMA-IR) and inflammatory markers; there is limited information pertaining to levels of plasminogen activator inhibitor-1 (PAI-1) and Monocyte Chemoattractant Protein -1 (MCP-1). Therefore, this study sought to examine the association between adherence to the dietary approaches to stop hypertension (DASH) diet and levels of inflammatory factors PAI-1, MCP-1, and HOMA-IR.

METHODS

This cross-sectional study was performed on 305 obese and overweight women. The typical food intake of individuals was assessed using the 147 items semi-quantitative food frequency questionnaire (FFQ). Body components were measured for all participants. Insulin resistance was estimated by homeostasis model assessment (HOMA), and biochemical parameters were examined.

RESULTS

No significant relationship was observed between the DASH diet and MCP-1 (P-trend = 0.70), PAI-1 (P-trend = 0.92), or HOMA-IR (P-trend = 0.08) in the crude model. However, there was a significant inverse relationship between the DASH diet and HOMA-IR (P-trend = 0.03) after adjusting for age, BMI, and physical activity.

CONCLUSION

This study showed that higher adherence to DASH pattern is inversely correlated with HOMA-IR in overweight and obese women.

Nonpharmacologic Interventions for Reducing Blood Pressure in Adults With Prehypertension to Established Hypertension

Background

Nonpharmacologic interventions that modify lifestyle can lower blood pressure (BP) and have been assessed in numerous randomized controlled trials and pairwise meta‐analyses. It is still unclear which intervention would be most efficacious.

Methods and Results

Bayesian network meta‐analyses were performed to estimate the comparative effectiveness of different interventions for lowering BP. From 60 166 potentially relevant articles, 120 eligible articles (14 923 participants) with a median follow‐up of 12 weeks, assessing 22 nonpharmacologic interventions, were included. According to the surface under the cumulative ranking probabilities and Grading of Recommendations Assessment, Development and Evaluation (GRADE) quality of evidence, for adults with prehypertension to established hypertension, high‐quality evidence indicated that the Dietary Approach to Stop Hypertension (DASH) was superior to usual care and all other nonpharmacologic interventions in lowering systolic BP (weighted mean difference, 6.97 mm Hg; 95% credible interval, 4.50–9.47) and diastolic BP (weighted mean difference, 3.54 mm Hg; 95% credible interval, 1.80–5.28). Compared with usual care, moderate‐ to high‐quality evidence indicated that aerobic exercise, isometric training, low‐sodium and high‐potassium salt, comprehensive lifestyle modification, breathing‐control, and meditation could lower systolic BP and diastolic BP. For patients with hypertension, moderate‐ to high‐quality evidence suggested that the interventions listed (except comprehensive lifestyle modification) were associated with greater systolic BP and diastolic BP reduction than usual care; salt restriction was also effective in lowering both systolic BP and diastolic BP. Among overweight and obese participants, low‐calorie diet and low‐calorie diet plus exercise could lower more BP than exercise.

Conclusions

DASH might be the most effective intervention in lowering BP for adults with prehypertension to established hypertension. Aerobic exercise, isometric training, low‐sodium and high‐potassium salt, comprehensive lifestyle modification, salt restriction, breathing‐control, meditation and low‐calorie diet also have obvious effects on BP reduction.

Influence of Dietary Approaches to Stop Hypertension (DASH) diet on blood pressure: a systematic review and meta-analysis on randomized controlled trials

BACKGROUND AND AIMS

Findings were not consistent on the therapeutic effect of Dietary Approaches to Stop Hypertension (DASH) diet on blood pressure. We aimed to review systematically and perform a meta-analysis to assess the magnitude of the effect of the DASH diet on blood pressure in randomized controlled trials (RCTs) among adults.

METHODS AND RESULTS

We conducted a systematic review and random effects meta-analysis of all RCTs which evaluated the effect of the DASH diet on blood pressure including published papers until June 2013, using PubMed, ISI Web of Science, Scopus and Google scholar database. Subgroup analysis and meta-regression were used to find out possible sources of between-study heterogeneity. Seventeen RCTs contributing 20 comparisons with 2561 participants were included. Meta-analysis showed that the DASH diet significantly reduced systolic blood pressure by 6.74 mmHg (95%CI: -8.25, -5.23, I(2) = 78.1%) and diastolic blood pressure by 3.54 mmHg (95%CI: -4.29, -2.79, I(2) = 56.7%). RCTs with the energy restriction and those with hypertensive subjects showed a significantly greater decrease in blood pressure. Meta-regression showed that mean baseline of SBP and DBP was explained 24% and 49% of the variance between studies for SBP and DBP, respectively.

CONCLUSION

The results revealed the profitable reducing effect of the DASH-like diet on both systolic and diastolic blood pressure in adults; although there was a variation in the extent of the fall in blood pressure in different subgroups.

Obesity and the renin- angiotensin-aldosterone system

The renin-angiotensin-aldosterone system (RAAS) is a key regulator of cardiovascular function. RAAS activity is upregulated in obesity despite concurrent renal sodium retention, which is a hallmark and principle determinant of obesity-associated hypertension. The contribution of adipose tissue to increased angiotensinogen and aldosterone plasma levels in obesity is probably due to the secretion of angiotensinogen and, as yet, unidentified aldosterone secretagogues by adipocytes. Increased circulating renin activity, on the other hand, is probably due to increased sympathetic activity in the obese. Modest weight reduction significantly reduces RAAS activity by uncertain mechanisms. Pharmacological blockade of the RAAS yielded promising results, both with regard to cardiovascular function and metabolic complications of obesity. These studies suggest that the activated RAAS is a prime pharmacological target for reducing the cardiometabolic risk in obese patients.

Fiber and Cardiovascular Disease Risk

Dietary fiber consists of edible parts of plants or analogous carbohydrates that are resistant to digestion and absorption in the human small intestine. Fiber can be classified as a dietary source (eg, cereal, fruit, vegetable, or legume) or as a supplement. Based on chemical properties, fiber can be divided to water-soluble (eg, beta-glucans, pectin, and guar) and insoluble (eg, cellulose and lignin) forms. An increasing number of observational findings have reported a lower incidence of coronary heart disease in subjects who report consuming diets high in fiber. Dietary fiber is thought to affect several cardiovascular disease (CVD) risk factors. Soluble fiber decreases serum total and low-density lipoprotein cholesterol concentrations and improves insulin resistance. The effect of fiber on inflammatory markers and coagulation is not yet well established. While soluble, gel-forming fiber has beneficially affected CVD risk factors, food sources of mainly insoluble fibers, primarily contributed by cereal products, have been the most consistently associated with lower incidence rates of CVD. Despite this contradiction, the evidence promotes a food-based approach favoring increased intake of whole-grain cereals, fruit, and vegetables providing a mixture of different types of fibers for CVD prevention.