Pistachio nut consumption modifies systemic hemodynamics, increases heart rate variability, and reduces ambulatory blood pressure in well-controlled type 2 diabetes: a randomized trial

The Cardioprotective Properties of Selected Nuts: Their Functional Ingredients and Molecular Mechanisms

Nuts have been known as a nutritious food since ancient times and can be considered part of our original diet: they are one of the few foods that have been eaten in the same form for thousands of years. They consist of various dry fruits and seeds, with the most common species being almonds (Prunus dulcis), hazelnuts (Corylus avellana), cashews (cashew nuts, Anacardium occidentale), pistachios (Pistacia vera), walnuts (Italian nuts, Juglans regia), peanuts (Arachia hypogaca), Brazil nuts (Bartholletia excels), pecans (Corya illinoinensis), macadamia nuts (Macademia ternifolia) and pine nuts. Both in vitro and in vivo studies have found nuts to possess a range of bioactive compounds with cardioprotective properties, and hence, their consumption may play a role in preventing and treating cardiovascular diseases (CVDs). The present work reviews the current state of knowledge regarding the functional ingredients of various nuts (almonds, Brazil nuts, cashew nuts, hazelnuts, macadamia nuts, peanuts, pecan nuts, pine nuts, pistachios, and walnuts) and the molecular mechanisms of their cardioprotective action. The data indicate that almonds, walnuts and pistachios are the best nut sources of bioactive ingredients with cardioprotective properties.

Tree Nut and Peanut Consumption and Risk of Cardiovascular Disease: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Cardiovascular disease (CVD) is the leading cause of death globally. Habitual consumption of tree nuts and peanuts is associated with cardioprotective benefits. Food-based dietary guidelines globally recommend nuts as a key component of a healthy diet. This systematic review and meta-analysis were conducted to examine the relationship between tree nut and peanut consumption and risk factors for CVD in randomized controlled trials (RCTs) (PROSPERO: CRD42022309156). MEDLINE, PubMed, CINAHL, and Cochrane Central databases were searched up to 26 September, 2021. All RCT studies that assessed the effects of tree nut or peanut consumption of any dose on CVD risk factors were included. Review Manager software was used to conduct a random effect meta-analysis for CVD outcomes from RCTs. Forest plots were generated for each outcome, between-study heterogeneity was estimated using the I2 test statistic and funnel plots and Egger's test for outcomes with ≥10 strata. The quality assessment used the Health Canada Quality Appraisal Tool, and the certainty of the evidence was assessed using grading of recommendations assessment, development, and evaluation (GRADE). A total of 153 articles describing 139 studies (81 parallel design and 58 cross-over design) were included in the systematic review, with 129 studies in the meta-analysis. The meta-analysis showed a significant decrease for low-density lipoprotein (LDL) cholesterol, total cholesterol (TC), triglycerides (TG), TC:high-density lipoprotein (HDL) cholesterol, LDL cholesterol:HDL cholesterol, and apolipoprotein B (apoB) following nut consumption. However, the quality of evidence was "low" for only 18 intervention studies. The certainty of the body of evidence for TC:HDL cholesterol, LDL cholesterol:HDL cholesterol, and apoB were "moderate" because of inconsistency, for TG were "low," and for LDL cholesterol and TC were "very low" because of inconsistency and the likelihood of publication bias. The findings of this review provide evidence of a combined effect of tree nuts and peanuts on a range of biomarkers to create an overall CVD risk reduction.

Believe It or 'Nut': Why It Is Time to Set the Record Straight on Nut Protein Quality: Pistachio (Pistacia vera L.) Focus

There are growing public health movements to transition towards diets that are plant-based. However, confusion exists with concerns that plant-based proteins (including nuts) may be inferior with respect to protein quality. The present publication evaluates the evolution of protein quality concepts and explains the protein science related to pistachios. Pistachio nuts are a plant-based complete protein providing all nine EAAs in addition to an array of nutrients and phytochemicals. They have a PDCAAS of 73 and 81%, (raw and roasted pistachios, respectively), higher than that of many other tree nuts. From an environmental perspective transitioning towards plant-based diets (including nuts) could have potential to reduce total/green water footprints. Dietary guidelines are evolving yet nuts such as pistachios do not always have a clear place within these. Now appears to be a pertinent time to look at protein quality from the perspective of whole daily diets and dietary patterns, factoring in both health and environmental outcomes. Given updated modes of thinking, nuts such as pistachios have an important role to play in terms of providing ready-to-eat, good-quality, plant-based protein within daily diets.

Dietary Approaches to Stop Hypertension via Indo-Mediterranean Foods, May Be Superior to DASH Diet Intervention

Western-type diet with high salt and sugar, sedentary behavior, obesity, tobacco and alcoholism are important risk factors for hypertension. This review aims to highlight the role of western diet-induced oxidative stress and inflammation in the pathogenesis of hypertension and the role of various types of diets in its prevention with reference to dietary approaches to stop hypertension (DASH) diet. It seems that it is crucial to alter the western type of diet because such diets can also predispose all CVDs. Western diet-induced oxidative stress is characterized by excessive production of reactive oxygen species (ROS) with an altered oxidation-reduction (redox) state, leading to a marked increase in inflammation and vascular dysfunction. Apart from genetic and environmental factors, one important cause for differences in the prevalence of hypertension in various countries may be diet quality, deficiency in functional foods, and salt consumption. The role of the DASH diet has been established. However, there are gaps in knowledge about the role of some Indo-Mediterranean foods and Japanese foods, which have been found to decrease blood pressure (BP) by improving vascular function. The notable Indo-Mediterranean foods are pulses, porridge, spices, and millets; fruits such as guava and blackberry and vegetables, which may also decrease BPs. The Japanese diet consists of soya tofu, whole rice, in particular medical rice, vegetables and plenty of fish rich in fish oil, fish peptides and taurine that are known to decrease BPs. Epidemiological studies and randomized, controlled trials have demonstrated the role of these diets in the prevention of hypertension and metabolic diseases. Such evidence is still meager from Japan, although the prevalence of hypertension is lower (15-21%) compared to other developed countries, which may be due to the high quality of the Japanese diet. Interestingly, some foods, such as berries, guava, pumpkin seeds, carrots, soya beans, and spices, have been found to cause a decrease in BPs. Omega-3 fatty acids, fish peptide, taurine, dietary vitamin D, vitamin C, potassium, magnesium, flavonoids, nitrate and l-arginine are potential nutrients that can also decrease BPs. Larger cohort studies and controlled trials are necessary to confirm our views.

Nuts as a Dietary Enrichment with Selected Minerals-Content Assessment Supported by Chemometric Analysis

Nuts used as a snack and meal accompaniment supply plant protein and fatty acids that are beneficial for human health; however, they can also provide minerals. The aim of this study was to determine the content of selected elements that are often deficient in the diet (calcium, potassium, magnesium, selenium, and zinc) in nuts and determine whether they can be used to supplement deficiencies in the diet. In this study, we analyzed 10 types of nuts (n = 120 samples) that are consumed and available for sale in Poland. The content of calcium, magnesium, selenium, and zinc was determined by the atomic absorption spectrometry method, and flame atomic emission spectrometry was used for determination of potassium contents. The highest median calcium content was found in almonds (2825.8 mg/kg), the highest potassium content in pistachio nuts (15,730.5 mg/kg), the highest magnesium and selenium contents in Brazil nuts (10,509.2 mg/kg and 4348.7 μg/kg, respectively), and the highest zinc content in pine nuts (72.4 mg/kg). All the tested nuts are a source of magnesium, eight types of tested nuts are a source of potassium, six nut types are a source of zinc, and four nut types are a source of selenium; however, among the tested nuts, only almonds can be considered a source of calcium. Moreover, we found that selected chemometric methods can be useful in the classification of nuts. The studied nuts are valuable products that can be used to supplement the diet with selected minerals and can therefore be labelled as functional products crucial for disease prevention.

Why Should Pistachio Be a Regular Food in Our Diet?

The pistachio is regarded as a relevant source of biologically active components that, compared to other nuts, possess a healthier nutritional profile with low-fat content composed mainly of monounsaturated fatty acids, a high source of vegetable protein and dietary fibre, remarkable content of minerals, especially potassium, and an excellent source of vitamins, such as vitamins C and E. A rich composition in terms of phytochemicals, such as tocopherols, carotenoids, and, importantly, phenolic compounds, makes pistachio a powerful food to explore its involvement in the prevention of prevalent pathologies. Although pistachio has been less explored than other nuts (walnut, almonds, hazelnut, etc.), many studies provide evidence of its beneficial effects on CVD risk factors beyond the lipid-lowering effect. The present review gathers recent data regarding the most beneficial effects of pistachio on lipid and glucose homeostasis, endothelial function, oxidative stress, and inflammation that essentially convey a protective/preventive effect on the onset of pathological conditions, such as obesity, type 2 diabetes, CVD, and cancer. Likewise, the influence of pistachio consumption on gut microbiota is reviewed with promising results. However, population nut consumption does not meet current intake recommendations due to the extended belief that they are fattening products, their high cost, or teething problems, among the most critical barriers, which would be solved with more research and information.

The Effects of Peanuts and Tree Nuts on Lipid Profile in Type 2 Diabetic Patients: A Systematic Review and Meta-Analysis of Randomized, Controlled-Feeding Clinical Studies

Background: Type 2 diabetes mellitus was found to be associated with metabolic disorders, particularly abnormal glucose and lipid metabolism. Dietary food choices may have profound effects on blood lipids. The primary objective of this study was to examine the effects of peanuts and tree nuts intake on lipid profile in patients with type 2 diabetes.

Methods: According to preferred reporting items for systematic reviews and meta-analysis guidelines, we performed a systematic search of randomized controlled clinical trials and systematic reviews published in PubMed, Web of Science, Embase, Scopus, and Cochrane library, from inception through June 2021. Studies in populations with type 2 diabetes, which compare nuts or peanuts to a controlled-diet group were included. We used the mean difference with 95% CIs to present estimates for continuous outcomes from individual studies. In addition, we used the GRADEpro tool to evaluate the overall quality of evidence.

Results: Sixteen studies involving 1,041 participants were eligible for this review. The results showed that peanuts and tree nuts supplementation did not induce significant changes in low-density lipoprotein-cholesterol (LDL-C) (mean difference = −0.11; 95%CI: −0.25 – 0.03, p = 0.117) and high-density lipoprotein-cholesterol (HDL-C) (mean difference = 0.01; 95%CI: −0.01 – 0.04, p = 0.400) in patients with type 2 diabetics. In addition, we found that peanuts and tree nuts intake may cause a significantly reduction in total cholesterol (TC) (mean difference = −0.14; 95%CI: −0.26 – −0.02, p = 0.024) and triglyceride (TG) (mean difference = −0.10; 95%CI: −0.17 – −0.02, p = 0.010). In the subgroup analysis, a significantly greater reduction in TC was observed in studies which duration was <12 weeks (mean difference = −0.22; 95%CI: −0.37 – −0.08, p = 0.002). The quality of the body of evidence was “moderate” for TC and TG, the quality of evidence for LDL-C and HDL-C were “low.”

Conclusion: Our findings suggest that consuming peanuts and tree nuts might be beneficial to lower TC concentration and TG concentration in type 2 diabetics subjects. Furthermore, peanuts and tree nuts supplementation could be considered as a part of a healthy lifestyle in the management of blood lipids in patients with type 2 diabetes. Given some limits observed in the current studies, more well-designed trials are still needed.

Effects of pistachios on anthropometric indices, inflammatory markers, endothelial function and blood pressure in adults: a systematic review and meta-analysis of randomised controlled trials

Evidence suggests that eating nuts may reduce the risk of CVD. This study was intended to pool the data of all randomised controlled trials (RCT) available to determine if pistachios confer a beneficial effect on anthropometric indices, inflammatory markers, endothelial dysfunction and blood pressure. Without language restriction, PubMed, Scopus, Cochrane Library and Web of Science were searched for articles published from the earliest records to June 2019 investigating the effect of pistachio consumption on inflammation, endothelial dysfunction and hypertension. Mean difference (MD) was pooled using a random effects model. The Cochrane risk of bias tool was used to evaluate the quality of the studies. The meta-analysis of thirteen RCT with 563 participants indicated that pistachio consumption significantly decreased systolic blood pressure (SBP) (MD: -2·12 mmHg, 95 % CI -3·65, -0·59, P = 0·007), whereas changes in flow-mediated dilation (MD: 0·94 %, 95 % CI -0·99, 2·86, P = 0·813), diastolic blood pressure (MD: 0·32 mmHg, 95 % CI -1·37, 2·02, P = 0·707), C-reactive protein (MD: 0·00 mg/l, 95 % CI -0·21, 0·23, P = 0·942), TNF-α (MD: -0·09 pg/ml, 95 % CI -0·38, 0·20, P = 0·541), body weight (MD: 0·09 kg, 95 % CI -0·38, 0·69, P = 0·697), BMI (MD: 0·07 kg/m2, 95 % CI -0·16, 0·31, P = 0·553) and waist circumference (MD: 0·77 cm, 95 % CI -0·09, 1·64, P = 0·140) were not statistically significant. This systematic review and meta-analysis suggested the efficacy of pistachio consumption to reduce SBP levels. However, further large-scale studies are needed to confirm these results.

Effect of tree nuts on glycemic outcomes in adults with type 2 diabetes mellitus: a systematic review

OBJECTIVE

The objective of this review was to synthesize the best available research evidence regarding the effectiveness of tree nuts on glycemic outcomes in adults with type 2 diabetes mellitus.

INTRODUCTION

There has been an increase in the use of complementary therapy, particularly botanical products, for management of type 2 diabetes mellitus. It has been reported that increasing mono- and polyunsaturated fatty acids in diet effectively lowers the risk of development of type 2 diabetes mellitus. Hence, it was hypothesized that consumption of nuts, which are high in polyunsaturated fatty acids and mono-unsaturated fatty acids, may aid in preventing diabetes and reducing levels of blood glucose by reducing glycemic load by displacing dietary carbohydrates present in diet.

INCLUSION CRITERIA

This systematic review included randomized controlled trials that compared the consumption of any type and form of tree nut with a placebo or any other intervention in adults with type 2 diabetes mellitus. Trials were included if they measured fasting blood glucose, postprandial blood glucose, and/or glycated hemoglobin. Trials that assessed triglyceride levels and weight postintervention were also considered for inclusion. Trials were restricted to the English language.

METHODS

A three step search of PubMed, CINAHL, Embase, Trip database, and Cochrane Central Register of Controlled Trials (CENTRAL) was done in July 2019. To find unpublished studies, ClinicalTrials.gov and Google Scholar were searched. Studies from the search were reviewed against the inclusion criteria by two reviewers. The JBI critical appraisal checklist for randomized controlled trials was used to assess the potential studies for methodological quality. A meta-analysis and subgroup analysis was conducted among trials with the same type of intervention and outcome measures. Results are presented in a narrative format where statistical pooling was not possible.

RESULTS

Fifteen trials were included with a total sample size of 667. Consumption of pistachios demonstrated a significant reduction in triglyceride levels (mmol/L) at three month or earlier follow-up (mean difference [MD] -0.28; confidence interval -0.33, -0.23; P <0.00001). The meta-analysis including all tree nuts combined showed reduction in both fasting blood glucose and glycated hemoglobin (MD -0.26 mmol/L and -0.11% respectively) at three month or earlier follow-up. The subgroup analysis demonstrated MD of -0.45, -0.16, and -0.90 mmol/L in fasting blood glucose following ingestion of walnuts, almonds, and hazelnuts, respectively, and -0.17% in glycated hemoglobin following ingestion of walnuts at three month or earlier follow-up. Although not clinically significant, these figures give an indication that further research with larger sample sizes and longer follow-up may show encouraging results.

CONCLUSIONS

The authors found that pistachio consumption for three months or less significantly reduced triglyceride levels. Other tree nuts (walnuts, almonds, and hazelnuts) reduced fasting blood glucose and glycated hemoglobin levels by varying degrees. Further robust randomized controlled trials with power calculation-based sample size, comparing same type, dose, and method of nut intervention, will provide more evidence. For now, clinical decisions should be based on standard practice local guidelines.

SYSTEMATIC REVIEW REGISTRATION NUMBER

PROSPERO CRD42019133558.

The association between left ventricular hypertrophy and consumption of nuts, including peanuts, pine nuts, and almonds

BACKGROUND AND AIMS

Studies have reported that nut consumption is potentially beneficial in preventing cardiovascular disease. However, data are insufficient regarding the association between nut consumption and left ventricular hypertrophy (LVH).

METHODS AND RESULTS

In the Kangbuk Samsung Health Study, the participants were 34,617 men and 12,257 women who completed a food-frequency questionnaire for nut consumption and received echocardiography. Nut consumption was evaluated only for peanuts, pine nuts, and almonds defining 15 g as one serving/servings dose. Multivariable adjusted odds ratio (OR) and 95% confidence interval (CI) for LVH were evaluated according to the consumption frequency of one serving dose of nut. The frequency of nut consumption was categorized into five groups (<1/month, 1/month-1/week, 1-2/week, 2-4/week, and ≥4/week). The subgroup analysis was conducted by dividing the participants into the following two groups: the nonhypertensive/nondiabetic group and hypertensive or diabetic group. In women, nut consumption ≥2/week had the lower multivariable adjusted OR and 95% CI for LVH (2-4/week: 0.46 [0.26-0.81] and ≥4/week: 0.48 [0.25-0.92]) when compared with nut consumption <1/month. This association was identically observed in the subgroup analysis for women without hypertension and diabetes mellitus (DM) and women with hypertension or DM. However, men did not show the significant association.

CONCLUSION

In women, nut consumption ≥2/week was associated with the decreased probability of LVH. Further research studies should investigate whether the beneficial effect of nut consumption on LV structure results in better cardiovascular prognosis.

Pistachios and cardiometabolic risk factors: A systematic review and meta-analysis of randomized controlled clinical trials

BACKGROUND

Previous experimental studies have reported that pistachios can elicit positive effects on lipid profile, blood pressure, and inflammation; however, a meta-analysis of the available evidence has yet to be performed.

OBJECTIVE

the aim of this study was to conduct systematic review and meta-analysis of the effect of pistachio enriched diets on cardiometabolic risk factors, such as weight, BMI, blood pressure, serum lipids, blood glucose, and inflammatory biomarkers.

DESIGN

A literature search was carried out for RCTs in medical databases, including PubMed/MEDLINE, Scopus, and Cochrane databases, with no time limitation up to August 2019, and conducted in accordance with the Preferred Reporting Items of Systematic Reviews and Meta-Analysis guidelines.

RESULTS

11 RCTs, with 506 participants, that reported the effect of pistachios consumption on cardiometabolic risk factors were included in this systematic review and meta-analysis. Our findings indicated that pistachios consumption significantly reduced FBS (WMD: -3.73, 95 % CI: -6.99, -0.46, I² = 99 %), TC/HDL (WMD: -0.46, 95 % CI: -0.76, -0.15, I² = 95 %), LDL/HDL (WMD: -0.24, 95 % CI: -0.38, -0.11, I² = 96 %), HbA1C (WMD: -0.14, 95 % CI: -0.26, -0.02, I² = 60 %), Insulin (WMD: -2.43, 95 % CI: -4.85, -0.001, I² = 58 %), SBP (WMD: -3.10, 95 % CI: -5.35, -0.85, I² = 63 %), and MDA (WMD: -0.36, 95 % CI: -0.49, -0.23, I² = 0%). Importantly, we did not observe adverse effects of pistachios consumption on BMI or blood pressure.

CONCLUSION

This systematic review and meta-analysis demonstrates that pistachios consumption can elicit a beneficial effect on some cardiometabolic risk factors. All previous clinical studies are well designed but some points have still remained unclear including the effects of different pistachios dosages on cardio metabolic risk factors and efficacy of pistachios consumption in preventing endothelial dysfunction. Further examination is required to determine the effect of pistachios consumption on further endothelial function risk factors.

Effects of Pistachio Consumption in a Behavioral Weight Loss Intervention on Weight Change, Cardiometabolic Factors, and Dietary Intake

Epidemiological studies have linked regular nut consumption with lower body mass index and reduced likelihood of weight gain in adulthood. Nuts can displace other foods in the diet, and thus, promote a healthier dietary pattern. The purpose of this study was to examine the effect of pistachio nut consumption in overweight/obese adults. This randomized controlled study enrolled non-diabetic overweight/obese adults (n = 100) assigned to a 4-month behavioral weight loss intervention only group (controls) or also prescribed 1.5 oz/day (42 g/day) of pistachios (pistachio group). Outcomes were change in body weight, cardiometabolic factors, and dietary intake. Percent weight change was similar in the two groups (−5.1 [0.5] (mean [SE])% in the control group and −4.9 [0.6]% in the pistachio group, and body mass index (BMI) and waist circumference were reduced in both groups (time effect p ≤ 0.05). The pistachio group (but not the control group) exhibited a significant reduction in both systolic and diastolic blood pressure (time effect p = 0.01). Plasma alpha-carotene, beta-carotene, and lutein concentrations increased significantly in the pistachio group (time effect p < 0.05). Pistachio consumption was associated with increased dietary fiber intake and decreased consumption of sweets. Regular consumption of pistachios was associated with a comparable degree of weight loss, and similar reductions in BMI and waist circumference, in overweight/obese men and women compared to controls, and favorable changes in the diet, in the context of a behavioral weight loss intervention.

Snacking on Whole Almonds for Six Weeks Increases Heart Rate Variability during Mental Stress in Healthy Adults: A Randomized Controlled Trial

Cardiac autonomic regulation can be indirectly measured by heart rate variability (HRV). Low HRV, which can be induced by mental stress, is a predictor of risk of sudden cardiac death. Few studies have investigated cause-and-effect relationships between diet and HRV. Nut consumption is associated with CVD risk reduction, but the impact on HRV, particularly in response to stress, is unclear. Men and women (30–70 y) with above average risk of developing CVD were randomly assigned in a 6-week randomized, controlled, parallel arm trial to consume either whole almond or isocaloric control snacks (20% of daily estimated energy requirement). Control snacks contained the average nutrient profile of UK snacks. Five-minute periods of supine heart rate (HR) and HRV were measured at resting and during mental stress (Stroop color-word test) at baseline and six weeks. High frequency (HF) power, which reflects parasympathetic regulation of HR, was increased following almonds during the mental stress task relative to control (mean difference between groups 124 ms2; 95% CI 11, 237; p = 0.031, n = 105), but other indices were unaffected. Snacking on whole almonds instead of typical snacks may reduce risk of CVD partly by ameliorating the suppression of HRV during periods of mental stress.

Snacking on whole almonds for 6 weeks improves endothelial function and lowers LDL cholesterol but does not affect liver fat and other cardiometabolic risk factors in healthy adults: the ATTIS study, a randomized controlled trial

BACKGROUND

There is convincing evidence that daily whole almond consumption lowers blood LDL cholesterol concentrations, but effects on other cardiometabolic risk factors such as endothelial function and liver fat are still to be determined.

OBJECTIVES

We aimed to investigate whether isoenergetic substitution of whole almonds for control snacks with the macronutrient profile of average snack intakes, had any impact on markers of cardiometabolic health in adults aged 30-70 y at above-average risk of cardiovascular disease (CVD).

METHODS

The study was a 6-wk randomized controlled, parallel-arm trial. Following a 2-wk run-in period consuming control snacks (mini-muffins), participants consumed either whole roasted almonds (n = 51) or control snacks (n = 56), providing 20% of daily estimated energy requirements. Endothelial function (flow-mediated dilation), liver fat (MRI/magnetic resonance spectroscopy), and secondary outcomes as markers of cardiometabolic disease risk were assessed at baseline and end point.

RESULTS

Almonds, compared with control, increased endothelium-dependent vasodilation (mean difference 4.1%-units of measurement; 95% CI: 2.2, 5.9), but there were no differences in liver fat between groups. Plasma LDL cholesterol concentrations decreased in the almond group relative to control (mean difference -0.25 mmol/L; 95% CI: -0.45, -0.04), but there were no group differences in triglycerides, HDL cholesterol, glucose, insulin, insulin resistance, leptin, adiponectin, resistin, liver function enzymes, fetuin-A, body composition, pancreatic fat, intramyocellular lipids, fecal SCFAs, blood pressure, or 24-h heart rate variability. However, the long-phase heart rate variability parameter, very-low-frequency power, was increased during nighttime following the almond treatment compared with control (mean difference 337 ms2; 95% CI: 12, 661), indicating greater parasympathetic regulation.

CONCLUSIONS

Whole almonds consumed as snacks markedly improve endothelial function, in addition to lowering LDL cholesterol, in adults with above-average risk of CVD.This trial was registered at clinicaltrials.gov as NCT02907684.

Effects of nut and seed consumption on markers of glucose metabolism in adults with prediabetes: a systematic review of randomised controlled trials

The primary aim was to investigate the effects of nut and seed consumption on markers of glucose metabolism in adults with prediabetes. Studies with a randomised controlled trial (RCT) design, comparing the effects of a diet containing nuts or seeds against a diet without nuts or seeds in adults with prediabetes, were considered eligible. Primary outcome measures included fasting plasma glucose (FPG), 2-h plasma glucose during oral glucose tolerance test and glycated Hb (HbA1c) concentrations. Studies were identified by searching PubMed and Scopus electronic databases and by checking full texts and reference lists of relevant records. Risk of bias was assessed using the Cochrane Collaboration's tool. We included five RCT involving 371 adults with prediabetes or at risk of diabetes; three RCT investigated the effects of whole nut consumption and two the effects of ground flaxseed consumption. Consumption of 57 g/d pistachios or mean intake of 60 g/d almonds for 4 months improved FPG and fasting plasma insulin (FPI) concentrations, insulin resistance, cellular glucose uptake in lymphocytes and β-cell function. Consumption of 56 g/d walnuts for 6 months was not found to affect FPG or HbA1c concentrations. Consumption of 13 g/d flaxseed for 3 months improved FPG and FPI concentrations and insulin resistance. In a second study, however, flaxseed consumption was not found to affect markers of glucose metabolism. The risk of bias was generally low, thus the reported results could be reliable. Further investigation of nut and seed consumption effects in the field of prediabetes is warranted.

Daily consumption of pistachios over 12 weeks improves dietary profile without increasing body weight in healthy women: A randomized controlled intervention

Dietary guidelines around the world recommend the regular intake of nuts because of their nutrient contribution to the diet and reported health benefits. However, consumers are often reluctant to include nuts in their diet due to the high caloric density of nuts. In a 12-week randomized, controlled intervention, we investigated how adding a pistachio portion to the daily diet affects body weight and composition, satiety, energy and nutrient intake. Sixty healthy pre-menopausal women who did not typically consume nuts were randomly assigned to a control or an experimental groups. Experimental participants (n = 30) consumed 44 g (250 kcal) pistachios mid-morning while controls (n = 30) maintained their current eating habits for 12 weeks. Ad libitum food intake and appetite sensations following the pistachio portion were assessed in all participants before and after the intervention in four 2-consecutive-day test sessions (under laboratory and then free-living conditions). Body weight and composition (DXA) were unchanged in both groups after 12 weeks. Pre- and post-intervention tests showed that ad libitum intake adjusted to the pistachio portion, mostly via reduced intakes of carbohydrates and starch, in parallel with decreased hunger and increased satiety following the morning snack. Intakes of MUFA, PUFA, linoleic acid, thiamin, pyridoxine, copper, manganese, and zinc were significantly higher among women consuming the pistachio snack, in spite of compensatory adjustments in intake. In conclusion, daily intake of 44 g pistachios improved nutrient intake without affecting body weight or composition in healthy women. The additional calories provided by the pistachios induced satiety and sufficient adjustment of intake to prevent body weight changes. CLINICAL TRIAL REGISTRY NUMBER: NCT03526120https://clinicaltrials.gov/ct2/show/NCT03526120.

Long-term association of nut consumption and cardiometabolic risk factors

BACKGROUND AND AIMS

Long-term associations between nut consumption and cardiometabolic risk factors are not well known. We investigated the relationship between nut consumption and cardiometabolic risk factors including dyslipidemia, hypertension, diabetes mellitus (DM), and obesity in a cohort of Iranian adults.

METHODS AND RESULTS

The study was conducted within the framework of the Isfahan Cohort Study on 1387 healthy participants. The participants were followed up for 12 years. A validated food frequency questionnaire was completed, and anthropometric measurements, blood pressure, and fasting serum lipids and blood sugar were evaluated in three phases. Mixed-effects binary logistic regression was applied to examine the associations between nut consumption and cardiometabolic risk factors. The participants were classified according to the tertiles of nut consumption as cut-points, and associations were evaluated between the thirds of nut intake. Subjects in the last third were less likely to have hypercholesterolemia [OR (95% CI): 0.76 (0.60-0.97)], hypertriglyceridemia [OR (95% CI): 0.74 (0.58-0.93)], and obesity [OR (95% CI): 0.79 (0.50-0.98)] but more likely to have DM [OR (95% CI): 1.85 (1.27-2.68)] than those in the first third. However, after adjustment for various potential confounders, the associations remained significant only for obesity [OR (95% CI): 0.67 (0.48-0.94)] and DM [OR (95% CI): 2.23 (1.37-3.64)].

CONCLUSION

After adjustment for potential confounders, we observed an inverse association for nut consumption and obesity but positive association for DM and nut intake. On the basis of our findings, it is suggested that incorporation of nuts into people's usual diet may have beneficial effects for individuals with lower risk such as subjects without DM.

Heart-rate variability: a biomarker to study the influence of nutrition on physiological and psychological health?

As the influence of diet on health may take place over a period of decades, there is a need for biomarkers that help to identify those aspects of nutrition that have either a positive or a negative influence. The evidence is considered that heart-rate variability (HRV) (the time differences between one beat and the next) can be used to indicate the potential health benefits of food items. Reduced HRV is associated with the development of numerous conditions for example, diabetes, cardiovascular disease, inflammation, obesity and psychiatric disorders. Although more systematic research is required, various aspects of diet have been shown to benefit HRV acutely and in the longer term. Examples include a Mediterranean diet, omega-3 fatty acids, B-vitamins, probiotics, polyphenols and weight loss. Aspects of diet that are viewed as undesirable, for example high intakes of saturated or trans-fat and high glycaemic carbohydrates, have been found to reduce HRV. It is argued that the consistent relationship between HRV, health and morbidity supports the view that HRV has the potential to become a widely used biomarker when considering the influence of diet on mental and physical health.

A Randomized Controlled Pilot Study to Assess Effects of a Daily Pistachio (Pistacia Vera) Afternoon Snack on Next-Meal Energy Intake, Satiety, and Anthropometry in French Women

Including nuts in the diet improves appetite control and does not lead to weight gain. However, for pistachios, evidence from randomized intervention studies is limited and there are no data on the effect of pistachios on satiety. The objective of this study was to assess the effect of daily consumption of pistachios as an afternoon snack on satiety, self-reported energy, self-reported nutrient intake, body weight, and body composition. This randomized controlled pilot study included two parallel groups of 30 healthy French women, in a free-living setting. For four weeks, groups were instructed to consume either 56 g (1318 kJ) of pistachios or 56 g of isoenergetic/equiprotein savory biscuits as an afternoon snack. Evening energy intake, changes in anthropometric measures, and daily intake of energy and selected nutrients were assessed. Visual analogue scales (VAS) were used to rate hunger, fullness, desire to eat, and prospective consumption. Satiety effects were not different between groups, as assessed by evening energy intake or VAS scores. Consuming pistachios or biscuits had no impact on body weight. Thiamin, vitamin B6, copper, and potassium intakes were significantly higher in the pistachio group. Consuming pistachios or biscuits as an afternoon snack resulted in similar post-snack food intake and subjective feelings of satiety. A daily pistachio snack for a month did not affect body weight or composition but it did improve micronutrient intake.

Physicochemical properties and health benefits of pistachio nuts

The genus of Pistacia plant systematically fits into the family of Anacardiaceae. Pistachios contain protein, carbohydrate, dietary fibers, fat, folic acid, vitamin K, magnesium and potassium, gama-tocopherols, phytochemicals, and polyphenols. Collectively, these constituents have been shown to possess antioxidant and anti-inflammatory functions to improve overall health when consumed as a healthy diet. We searched the following keywords within the literature databases: pistachio, heart disorders, lipids, weight, antioxidants, and allergy. Further searching theses keywords, we have found 50 articles in PubMed, 40 articles in ISI web of knowledge and 30 articles in Google Scholar. We have selected 100 articles, among them 80 articles were used as the references of this review. In the current article, we have discussed the most recent data published regarding the regulatory effects of pistachios on several clinical states such as heart related disorders, hyperlipidemia, hypertension, vascular stiffness and endothelial and gut functions, weight management, glucose metabolism, kidney function and finally allergies.

Update on the Impact, Diagnosis and Management of Cardiovascular Autonomic Neuropathy in Diabetes: What Is Defined, What Is New, and What Is Unmet

The burden of diabetic cardiovascular autonomic neuropathy (CAN) is expected to increase due to the diabetes epidemic and its early and widespread appearance. CAN has a definite prognostic role for mortality and cardiovascular morbidity. Putative mechanisms for this are tachycardia, QT interval prolongation, orthostatic hypotension, reverse dipping, and impaired heart rate variability, while emerging mechanisms like inflammation support the pervasiveness of autonomic dysfunction. Efforts to overcome CAN under-diagnosis are on the table: by promoting screening for symptoms and signs; by simplifying cardiovascular reflex tests; and by selecting the candidates for screening. CAN assessment allows for treatment of its manifestations, cardiovascular risk stratification, and tailoring therapeutic targets. Risk factors for CAN are mainly glycaemic control in type 1 diabetes mellitus (T1DM) and, in addition, hypertension, dyslipidaemia, and obesity in type 2 diabetes mellitus (T2DM), while preliminary data regard glycaemic variability, vitamin B12 and D changes, oxidative stress, inflammation, and genetic biomarkers. Glycaemic control prevents CAN in T1DM, whereas multifactorial intervention might be effective in T2DM. Lifestyle intervention improves autonomic function mostly in pre-diabetes. While there is no conclusive evidence for a disease-modifying therapy, treatment of CAN manifestations is available. The modulation of autonomic function by SGLT2i represents a promising research field with possible clinical relevance.

A unifying conceptual framework of factors associated to cardiac vagal control

Cardiac vagal control (CVC) reflects the activity of the vagus nerve regulating cardiac functioning. CVC can be inferred via heart rate variability measurement, and it has been positively associated to a broad range of cognitive, emotional, social, and health outcomes. It could then be considered as an indicator for effective self-regulation, and given this role, one should understand the factors increasing and decreasing CVC. The aim of this paper is to review the broad range of factors influencing CVC, and to provide a unifying conceptual framework to integrate comprehensively those factors. The structure of the unifying conceptual framework is based on the theory of ecological rationality, while its functional aspects are based on the neurovisceral integration model. The structure of this framework distinguishes two broad areas of associations: person and environment, as this reflects adequately the role played by CVC regarding adaptation. The added value of this framework lies at different levels: theoretically, it allows integrating findings from a variety of scientific disciplines and refining the predictions of the neurovisceral integration model; methodologically, it helps identifying factors that increase and decrease CVC; and lastly at the applied level, it can play an important role for society regarding health policies and for the individual to empower one's flourishing.

Enhancing cardiac vagal activity: Factors of interest for sport psychology

Self-regulation plays a critical role in sport performance. An objective, psychophysiological marker of self-regulation is cardiac vagal activity, the activity of the vagus nerve regulating cardiac functioning. The aim of this paper is to provide an overview of factors influencing cardiac vagal activity, which can be useful for athletes. Specifically, we organize this overview in two main domains: personal factors and environmental factors. Among the personal factors, we discuss the behavioral strategies that can be used by athletes: nutrition, non-ingestive oral habits, water immersion, body temperature reduction, sleeping habits, relaxation methods, cognitive techniques, praying, music, and exercise. Among environmental factors, we discuss those linked to the social (i.e., contact with humans and animals) and physical (i.e., aromas, lights, sounds, temperature, outdoor, altitude) environment. Future research directions are given, as well as practical implications for athletes and coaches.

Nut consumption and metabolic syndrome in US adolescents

OBJECTIVE

To determine whether nut intake is associated with the prevalence of metabolic syndrome in US adolescents.

DESIGN

A cross-sectional analysis of data from the National Health and Nutrition Examination Survey (NHANES) years 2003-2012. Anthropometric measurements, blood tests, 24 h diet recalls and demographic data were retrieved for participating adolescents. Metabolic syndrome was defined according to paediatric-modified Adult Treatment Panel III criteria. The exposure was defined as a nut intake ≥5 g/d.

SETTING

USA.

SUBJECTS

Individuals aged 12-19 years (n 2805).

RESULTS

Nut consumption was associated with lower odds for metabolic syndrome (crude OR=0·25; 95 % CI 0·11, 0·55; P≤0·001). This effect was independent of age, sex, race/ethnicity and family income:poverty ratio (adjusted OR=0·27; 95 % CI 0·12, 0·61; P=0·002), and was stable after controlling for nutritional covariates including intake of sugar and total energy consumption (OR=0·36; 95 % CI 0·16, 0·81; P=0·014).

CONCLUSION

Nut consumption of ≥5 g/d is independently associated with lower odds for metabolic syndrome in US adolescents.

Food groups and intermediate disease markers: a systematic review and network meta-analysis of randomized trials

Background

In previous meta-analyses of prospective observational studies, we investigated the association between food groups and risk of chronic disease.

Objective

The aim of the present network meta-analysis (NMA) was to assess the effects of these food groups on intermediate-disease markers across randomized intervention trials.

Design

Literature searches were performed until January 2018. The following inclusion criteria were defined a priori: 1) randomized trial (≥4 wk duration) comparing ≥2 of the following food groups: refined grains, whole grains, nuts, legumes, fruits and vegetables, eggs, dairy, fish, red meat, and sugar-sweetened beverages (SSBs); 2) LDL cholesterol and triacylglycerol (TG) were defined as primary outcomes; total cholesterol, HDL cholesterol, fasting glucose, glycated hemoglobin, homeostasis model assessment insulin resistance, systolic and diastolic blood pressure, and C-reactive protein were defined as secondary outcomes. For each outcome, a random NMA was performed, and for the ranking, the surface under the cumulative ranking curves (SUCRA) was determined.

Results

A total of 66 randomized trials (86 reports) comparing 10 food groups and enrolling 3595 participants was identified. Nuts were ranked as the best food group at reducing LDL cholesterol (SUCRA: 93%), followed by legumes (85%) and whole grains (70%). For reducing TG, fish (97%) was ranked best, followed by nuts (78%) and red meat (72%). However, these findings are limited by the low quality of the evidence. When combining all 10 outcomes, the highest SUCRA values were found for nuts (66%), legumes (62%), and whole grains (62%), whereas SSBs performed worst (29%).

Conclusion

The present NMA provides evidence that increased intake of nuts, legumes, and whole grains is more effective at improving metabolic health than other food groups. For the credibility of diet-disease relations, high-quality randomized trials focusing on well-established intermediate-disease markers could play an important role. This systematic review was registered at PROSPERO (www.crd.york.ac.uk/PROSPERO) as CRD42018086753.

Nuts and Cardiovascular Disease Prevention

PURPOSE OF REVIEW

We review recent epidemiological and clinical studies investigating the consumption of tree nuts and peanuts and cardiovascular disease (CVD) mortality as well as CVD risk factors.

RECENT FINDINGS

A greater consumption of tree nuts and peanuts is associated with a reduced risk of CVD mortality, as well as lower CVD events. Furthermore, risk factors associated with the development of CVD such as dyslipidemia, impaired vascular function, and hypertension are improved with regular tree nut and peanut consumption through a range of mechanism associated with their nutrient-rich profiles. There is weak inconsistent evidence for an effect of nut consumption on inflammation. There is emerging evidence that consuming tree nuts reduces the incidence of non-alcoholic fatty liver disease (NAFLD) and promotes diversity of gut microbiota, which in turn may improve CVD outcomes. Evidence for CVD prevention is strong for some varieties of tree nuts, particularly walnuts, and length of supplementation and dose are important factors for consideration with recommendations.

Nuts and Human Health Outcomes: A Systematic Review

There has been increasing interest in nuts and their outcome regarding human health. The consumption of nuts is frequently associated with reduction in risk factors for chronic diseases. Although nuts are high calorie foods, several studies have reported beneficial effects after nut consumption, due to fatty acid profiles, vegetable proteins, fibers, vitamins, minerals, carotenoids, and phytosterols with potential antioxidant action. However, the current findings about the benefits of nut consumption on human health have not yet been clearly discussed. This review highlights the effects of nut consumption on the context of human health.

Effect of pistachio on brachial artery diameter and flow-mediated dilatation: A systematic review and meta-analysis of randomized, controlled-feeding clinical studies

BACKGROUND

Results of previous clinical trials evaluating the effect of pistachio supplementation on endothelial reactivity (ER) are controversial.

AIMS

We aimed to assess the impact of pistachio on ER through systematic review of literature and meta-analysis of available randomized, controlled-feeding clinical studies (RCTs).

METHODS

The literature search included SCOPUS, PubMed-Medline, ISI Web of Science and Google Scholar databases up to 1st August 2017 to identify RCTs investigating the impact of pistachio on ER. Two independent reviewers extracted data on study characteristics, methods and outcomes. Overall, the impact of pistachio on ER was reported in 4 trials.

RESULTS

The meta-analysis did not suggest a significant change in brachial artery flow-mediated dilatation (FMD) (WMD: +0.28%; 95%CI: -0.58, 1.13; p = 0.525) while brachial artery diameter (BAD) improved (WMD: +0.04%; 95%CI: 0.03, 0.06; p<0.001) following pistachios consumption.

CONCLUSION

The present meta-analysis suggests a significant effect of pistachios on ER, affecting BAD but not FMD.

Phytochemical, ethnomedicinal uses and pharmacological profile of genus Pistacia

Pistacia genus belong to family Anacardiaceae and it is versatile in that its member species have food (P. vera), medicinal (P. lentiscus) and ornamental (P. chinensis) values. Various species of this genus have folkloric uses with credible mention in diverse pharmacopeia. As a trove of phenolic compounds, terpenoids, monoterpenes, flavonoids, alkaloids, saponins, fatty acids, and sterols, this genus has garnered pharmaceutical attention in recent times. With adequate clinical studies, this genus might be exploited for therapy of a multitude of inflammatory diseases, as promised by preliminary studies. In this regard, the ethnomedicinal, phytochemistry, biological potencies, risks, and scopes of Pistacia genus have been reviewed here.

Nut consumption and risk of cardiovascular disease, total cancer, all-cause and cause-specific mortality: a systematic review and dose-response meta-analysis of prospective studies

BACKGROUND

Although nut consumption has been associated with a reduced risk of cardiovascular disease and all-cause mortality, data on less common causes of death has not been systematically assessed. Previous reviews missed several studies and additional studies have since been published. We therefore conducted a systematic review and meta-analysis of nut consumption and risk of cardiovascular disease, total cancer, and all-cause and cause-specific mortality.

METHODS

PubMed and Embase were searched for prospective studies of nut consumption and risk of cardiovascular disease, total cancer, and all-cause and cause-specific mortality in adult populations published up to July 19, 2016. Summary relative risks (RRs) and 95% confidence intervals (CIs) were calculated using random-effects models. The burden of mortality attributable to low nut consumption was calculated for selected regions.

RESULTS

Twenty studies (29 publications) were included in the meta-analysis. The summary RRs per 28 grams/day increase in nut intake was for coronary heart disease, 0.71 (95% CI: 0.63-0.80, I2 = 47%, n = 11), stroke, 0.93 (95% CI: 0.83-1.05, I2 = 14%, n = 11), cardiovascular disease, 0.79 (95% CI: 0.70-0.88, I2 = 60%, n = 12), total cancer, 0.85 (95% CI: 0.76-0.94, I2 = 42%, n = 8), all-cause mortality, 0.78 (95% CI: 0.72-0.84, I2 = 66%, n = 15), and for mortality from respiratory disease, 0.48 (95% CI: 0.26-0.89, I2 = 61%, n = 3), diabetes, 0.61 (95% CI: 0.43-0.88, I2 = 0%, n = 4), neurodegenerative disease, 0.65 (95% CI: 0.40-1.08, I2 = 5.9%, n = 3), infectious disease, 0.25 (95% CI: 0.07-0.85, I2 = 54%, n = 2), and kidney disease, 0.27 (95% CI: 0.04-1.91, I2 = 61%, n = 2). The results were similar for tree nuts and peanuts. If the associations are causal, an estimated 4.4 million premature deaths in the America, Europe, Southeast Asia, and Western Pacific would be attributable to a nut intake below 20 grams per day in 2013.

CONCLUSIONS

Higher nut intake is associated with reduced risk of cardiovascular disease, total cancer and all-cause mortality, and mortality from respiratory disease, diabetes, and infections.

Novel Approaches to Investigate One-Carbon Metabolism and Related B-Vitamins in Blood Pressure

Hypertension, a major risk factor for heart disease and stroke, is the world's leading cause of preventable, premature death. A common polymorphism (677C→T) in the gene encoding the folate metabolizing enzyme methylenetetrahydrofolate reductase (MTHFR) is associated with increased blood pressure, and there is accumulating evidence demonstrating that this phenotype can be modulated, specifically in individuals with the MTHFR 677TT genotype, by the B-vitamin riboflavin, an essential co-factor for MTHFR. The underlying mechanism that links this polymorphism, and the related gene-nutrient interaction, with hypertension is currently unknown. Previous research has shown that 5-methyltetrahydrofolate, the product of the reaction catalysed by MTHFR, appears to be a positive allosteric modulator of endothelial nitric oxide synthase (eNOS) and may thus increase the production of nitric oxide, a potent vasodilator. Blood pressure follows a circadian pattern, peaking shortly after wakening and falling during the night, a phenomenon known as 'dipping'. Any deviation from this pattern, which can only be identified using ambulatory blood pressure monitoring (ABPM), has been associated with increased cardiovascular disease (CVD) risk. This review will consider the evidence linking this polymorphism and novel gene-nutrient interaction with hypertension and the potential mechanisms that might be involved. The role of ABPM in B-vitamin research and in nutrition research generally will also be reviewed.

Pistachios for Health: What Do We Know About This Multifaceted Nut?

Human beings have known about pistachio nuts since 6000 bc. Since then, pistachios have been systematically incorporated into the diet of various cultures. They are nutrient-dense nuts with a healthy nutritional profile that contains fiber, unsaturated fatty acids and antioxidant compounds.

Effects of pistachios on the lipid/lipoprotein profile, glycemic control, inflammation, and endothelial function in type 2 diabetes: A randomized trial

OBJECTIVE

The health benefits of regular nut consumption have been well-documented; however, effects on cardiovascular risk in diabetes are emerging. This study examined the effects of daily pistachio consumption on the lipid/lipoprotein profile, glycemic control, markers of inflammation, and endothelial function in adults with type 2 diabetes.

MATERIALS/METHODS

We enrolled 30 adults (40-74 years) with well-controlled type 2 diabetes (mean glycated hemoglobin 6.2%) in a randomized, crossover, controlled feeding study. After a 2-week run-in period, participants consumed nutritionally-adequate diets with pistachios (contributing 20% of total energy) or without pistachios for 4 weeks each, separated by a 2-week washout. We assessed fasting lipids/lipoproteins, glycemic measures (while fasted and during a 75 g oral glucose tolerance test), inflammatory markers, and endothelial function after each diet period.

RESULTS

Total cholesterol and the ratio of total to HDL cholesterol were significantly lower (p<0.05) following the pistachio diet (4.00 mmol/L and 4.06 mmol/L, respectively) compared to the control diet (4.15 mmol/L and 4.37 mmol/L, respectively). Triglycerides were significantly lower (p=0.003) following the pistachio diet (1.56 mmol/L) compared to the control diet (1.84 mmol/L). There were no treatment differences in fasting glucose and insulin, but fructosamine was significantly lower (p=0.03) following the pistachio diet (228.5 μmol/l) compared to the control diet (233.5 μmol/l). Inflammatory markers and endothelial function were unchanged.

CONCLUSION

Daily pistachio consumption can improve some cardiometabolic risk factors in adults with well-controlled type 2 diabetes. Our findings support recommendations that individuals with diabetes follow healthy dietary patterns that include nuts.

Effect of Low-Energy Diets Differing in Fiber, Red Meat, and Coffee Intake on Cardiac Autonomic Function in Obese Individuals With Type 2 Diabetes

OBJECTIVE

The autonomic nervous system (ANS) regulates both the cardiovascular system and energy balance and is disturbed in diabetes and obesity. The effect of different approaches of caloric restriction on ANS function has not been assessed in individuals with diabetes. Thus, we sought to determine whether low-energy diets differing in fiber, red meat, and coffee intake exert differential effects on cardiac autonomic function.

RESEARCH DESIGN AND METHODS

In this randomized parallel-group pilot trial, obese patients with type 2 diabetes were randomly allocated to consume either a diet high in cereal fiber, free of red meat, and high in coffee (n = 13) or a diet low in fiber, high in red meat, and coffee free (n = 15) over 8 weeks. Eight measures of heart rate variability (HRV) indicating vagal and/or sympathetic modulation over 3 h and inflammatory markers were determined during a hyperinsulinemic-euglycemic clamp.

RESULTS

After 8 weeks, both dietary interventions resulted in a mean weight loss of 5-6 kg, a mean decline in heart rate of 4-6 bpm, and improvement in vagally mediated HRV. However, the changes in HRV parameters from baseline to 8 weeks did not differ between the groups. In the entire study cohort, incremental HRV from baseline to 8 weeks was associated with enhanced oxidative glucose utilization (P < 0.05), but not with insulin sensitivity and inflammatory markers.

CONCLUSIONS

In obese patients with type 2 diabetes, energy restriction per se over 8 weeks contributed to improved cardiac vagal function in relation to improved oxidative glucose utilization. This preliminary finding should be verified in a confirmatory trial.

Noninvasive assessment of hemodynamics: a comparative analysis of fingertip pulse contour analysis and impedance cardiography

OBJECTIVE

Systemic hemodynamic assessment is useful for characterizing the underlying physiology of hypertension, selecting individualized treatment approaches, and understanding the underlying mechanisms of action of interventions. Invasive methods are not suitable for routine clinic or research use, and noninvasive methods such as impedance cardiography have technical and practical limitations. Fingertip pulse contour analysis using the Nexfin device is a novel alternative to noninvasive assessment of blood pressure and hemodynamics. Although both impedance cardiography and the Nexfin have been validated against invasive methods, the extent to which they are correlated with each other is unknown. This study is a comparative analysis of data simultaneously obtained by impedance cardiography and using the Nexfin device.

METHODS

As part of a larger clinical trial, 13 adults with type 2 diabetes completed cardiovascular reactivity testing on three occasions: at study baseline and after two 4-week dietary treatment periods. Blood pressure, hemodynamics, and heart rate variability were assessed at rest and during acute mental stress.

RESULTS

Blood pressure, heart rate, and heart rate variability data were significantly correlated between the two devices, but hemodynamic data (stroke volume, cardiac output, total peripheral resistance) were not significantly correlated. Both techniques detected treatment-related changes in blood pressure and total peripheral resistance, but significantly differed in the magnitude and/or direction of treatment effects.

CONCLUSION

We conclude that Nexfin is not an appropriate alternative to impedance cardiography for measurement of underlying hemodynamics in psychophysiological research, but may be useful for beat-to-beat monitoring of blood pressure and heart rate variability.