Role of dietary therapies in the prevention and treatment of hypertension

Exploring the association of dietary patterns with the risk of hypertension using principal balances analysis and principal component analysis

OBJECTIVE

In the field of nutritional epidemiology, principal component analysis (PCA) has been used extensively in identifying dietary patterns. Recently, compositional data analysis (CoDA) has emerged as an alternative approach for obtaining dietary patterns. We aimed to directly compare and evaluate the ability of PCA and principal balances analysis (PBA), a data-driven method in CoDA, in identifying dietary patterns and their associations with the risk of hypertension.

DESIGN

Cohort study. A 24-h dietary recall questionnaire was used to collect dietary data. Multivariate logistic regression analysis was used to analyse the association between dietary patterns and hypertension.

SETTING

2004 and 2009 China Health and Nutrition Survey.

PARTICIPANTS

A total of 3892 study participants aged 18-60 years were included as the subjects.

RESULTS

PCA and PBA identified five patterns each. PCA patterns comprised a linear combination of all food groups, whereas PBA patterns included several food groups with zero loadings. The coarse cereals pattern identified by PBA was inversely associated with hypertension risk (highest quintile: OR = 0·74 (95 % CI 0·57, 0·95); Pfor trend = 0·037). None of the five PCA patterns was associated with hypertension. Compared with the PCA patterns, the PBA patterns were clearly interpretable and accounted for a higher percentage of variance in food intake.

CONCLUSIONS

Findings showed that PBA might be an appropriate and promising approach in dietary pattern analysis. Higher adherence to the coarse cereals dietary pattern was associated with a lower risk of hypertension. Nevertheless, the advantages of PBA over PCA should be confirmed in future studies.

Effects of diet on hypertensive disorders during pregnancy: A cross-sectional study from a teaching hospital

Background:

Pregnancy is a positive, fulfilling experience for many, but it can put the mother at the risk of suffering ill-health, disability, or even maternal death. The common causes of maternal death include pregnancy-induced hypertension (PIH) or gestational hypertension or hypertensive disorders in pregnancy (HDP), post-partum hemorrhage, and pulmonary embolism. Modifications in lifestyle and diet have been widely advocated as a cost-effective strategy to prevent PIH.

Objectives:

To assess the role of dietary factors in PIH attending antenatal care services at a teaching hospital.

Materials and Methods:

Pregnant women who were attending the antenatal clinic who were diagnosed with hypertension in pregnancy and normotensive before the pregnancy were included in the study. As per the protocol, informed written consent, demographic details with clinical data were obtained from the patients. A total of 225 antenatal cases having hypertension in pregnancy were included in our study.

Results:

Majority of the study subjects (81.8%) were taking mixed diets, 50.2% consumed additional salt in their diet, the intake history of visible fat was given by 25.3% and 96.4% consumed tea while 52.9% had a history of consuming junk food. Among the 41 vegetarian study subjects with hypertension in pregnancy, the maximum subjects (73.1%) had preeclampsia followed by gestational hypertension in 23.6% the subjects. The relation between the type of diet and hypertension in pregnancy was found to be statistically insignificant. The relation between visible fat consumption and hypertension in pregnancy was found to be statistically significant.

Discussion:

The association of dietary factors with HDP could be explained by several factors. One being the high-calorie intake by women with known HDP and those without HDP. The imbalance between the energy intake and expenditure is a potential risk factor and leads to overweight or obesity.

Conclusion:

The consumption of additional salt in the diet, visible fat, and obesity was found to be associated with HDP in our study.

Long-term oral resveratrol intake provides nutritional preconditioning against myocardial ischemia/reperfusion injury: involvement of VDAC1 downregulation

SCOPE

This study elucidates the effects of long-term nutritional preconditioning by resveratrol on ischemia/reperfusion (I/R) injury and its underlying mechanisms.

METHODS AND RESULTS

Mice were treated with resveratrol at 2.0 mg/kg/day by gastric gavages for 6 wk. Then hearts were isolated and subjected to I/R injury in a Langendorff apparatus. Resveratrol significantly improved left ventricular pressure, ±dp/dtmax, and coronary flow; decreased the lactate dehydrogenase and creatine phosphokinase activities; and reduced the infarction size. Additionally, long-term oral resveratrol intake prevented mitochondrial permeability transition pore opening and subsequently inhibited mitochondria-mediated apoptosis, as demonstrated by decrease of cytochrome c release, inactivation of caspase-3, and reduction of terminal deoxynucleotidyl transferase mediated nick end labeling positive cells. Furthermore, resveratrol inhibited the upregulation of voltage-dependent anion channel 1 (VDAC1) expression induced by I/R injury. Local left-ventricle overexpression of VDAC1 by adenovirus diminished the protective effect of resveratrol against I/R injury, indicating that VDAC1 plays an important role in resveratrol-mediated cardioprotection.

CONCLUSION

Our data revealed that long-term oral intake of resveratrol sets nutritional preconditioning to cope with myocardial I/R injury. Strikingly, we found that resveratrol downregulates VDAC1, leading to prevention of mitochondrial permeability transition pore opening and cardiomyocyte apoptosis.

Chia flour supplementation reduces blood pressure in hypertensive subjects

The aim of this study was to investigate the effect of chia supplementation (Salvia hispanica L.) on blood pressure (BP) and its associated cardiometabolic factors in treated and untreated hypertensive individuals. The subjects were randomly assigned to one of the following groups: the hypertensive-drug treated (CHIA-MD, n = 10), hypertensive untreated (CHIA-NM, n = 9) and placebo (PLA-MD, n = 7) groups. The subjects consumed 35 g/day of either chia flour or a placebo for 12 weeks. The clinical and ambulatory BP, inflammation, oxidative stress and markers for nitric oxide were measured. While the PLA-MD group showed no changes in BP, there was a reduction in the mean clinical blood pressure (MBP) in the CHIA (111.5 ± 1.9 to 102.7 ± 1.5 mmHg, p < 0.001) and CHIA-MD (111.3 ± 2.2 to 100.1 ± 1.8 mmHg, p < 0.001) groups. The CHIA-NM group showed no reduction in the MBP but did show a decreased systolic BP (146.8 ± 3.8 to 137.3 ± 3.1 mmHg, p < 0.05). The clinical BP reduction was demonstrated by a 24 h ambulatory systolic reduction in all of the supplemented groups. However, the mean ambulatory BP was reduced only in the CHIA (98.1 ± 2.4 to 92.8 ± 2.2 mmHg, p < 0.05) group, and there was no change in the diastolic component in either of the CHIA groups. The lipid peroxidation was reduced in the CHIA (p = 0.04) and CHIA-NM (p = 0.02) groups compared with the PLA-MD group. A reduction in the plasma nitrite levels was observed only in the CHIA group (p = 0.02). Chia flour has the ability to reduce ambulatory and clinical BP in both treated and untreated hypertensive individuals.

Dietary approaches to prevent hypertension

Elevated blood pressure arises from a combination of environmental and genetic factors and the interactions of these factors. A substantial body of evidence from animal studies, epidemiologic studies, meta-analyses, and randomized controlled trials has demonstrated that certain dietary patterns and individual dietary elements play a prominent role in the development of hypertension. Changes in diet can lower blood pressure, prevent the development of hypertension, and reduce the risk of hypertension-related complications. Dietary strategies for the prevention of hypertension include reducing sodium intake, limiting alcohol consumption, increasing potassium intake, and adopting an overall dietary pattern such as the DASH (Dietary Approaches to Stop Hypertension) diet or a Mediterranean diet. In order to reduce the burden of blood pressure-related complications, efforts that focus on environmental and individual behavioral changes that encourage and promote healthier food choices are warranted.

[Non-pharmacological and pharmacological treatment of arterial hypertension: current situation]

A permanent and successful treatment of high blood pressure is based on a combination of non-pharmacological treatment measures and pharmacological therapy. The most proven non-pharmacological measures are physical and sports activities, weight reduction, dietary adaption and reduction of salt intake as well as nicotine abstinence and moderate alcohol consumption. A blood pressure reducing effect of evidence grade A was demonstrated for these 4 pillars of non-pharmacological therapy in studies. For pharmacological treatment five main substance groups are available: thiazide diuretics, ACE inhibitors, AT1 blockers, calcium channel blockers and beta blockers. A very good blood pressure reducing effect with an advantageous side effect profile has been proven for all substances. The initial high blood pressure therapy can be carried out with monotherapy but therapy with several antihypertensives is often necessary for the very varied combination of compounds which are available in a meaningful combination and dosage of effective ingredients. For the treatment of comorbid hypertensive patients recommendations are available for an individualized pharmacological treatment corresponding to the specific cardiovascular risk and comorbidity. High blood pressure therapy must be continuously carried out over many years. For permanent success of the therapy good compliance is indispensible which can be encouraged by integration in the therapy and should be regularly controlled.