A Mediterranean diet improves HbA1c but not fasting blood glucose compared to alternative dietary strategies: a network meta-analysis

Approach to the Treatment of Children and Adolescents with Obesity

Pediatric obesity continues to be an omnipresent disease; 1 in 5 children and adolescents have obesity in the United States. The comorbidities associated with youth-onset obesity tend to have a more severe disease progression in youth compared to their adult counterparts with the same obesity-related condition. A comorbidity of focus in this study is metabolism-associated steatotic liver disease (MASLD), which has rapidly evolved into the most common liver disease seen in the pediatric population. A direct association exists between the treatment of MASLD and the treatment of pediatric obesity. The current evidence supports that obesity treatment is safe and effective.

The effectiveness of the Mediterranean Diet for primary and secondary prevention of cardiovascular disease: An umbrella review

AIMS

This study aimed to review meta-analyses of randomised controlled trials that evaluated the effectiveness of the Mediterranean Diet for the primary and secondary prevention of cardiovascular disease.

METHODS

Five databases (Medline, Embase, Cochrane, CINAHL and ProQuest) were searched from inception to November 2022. Inclusion criteria were: (i) systematic review of randomised controlled studies with metanalysis; (ii) adults ≥18 years from the general population with (secondary prevention) and without (primary prevention) established cardiovascular disease; (iii) Mediterranean Diet compared with another dietary intervention or usual care. Review selection and quality assessment using AMSTAR-2 were completed in duplicate. GRADE was extracted from each review, and results were synthesised narratively.

RESULTS

Eighteen meta-analyses of 238 randomised controlled trials were included, with an 8% overlap of primary studies. Compared to usual care, the Mediterranean Diet was associated with reduced cardiovascular disease mortality (n = 4 reviews, GRADE low certainty; risk ratio range: 0.35 [95% confidence interval: 0.15-0.82] to 0.90 [95% confidence interval: 0.72-1.11]). Non-fatal myocardial infarctions were reduced (n = 4 reviews, risk ratio range: 0.47 [95% confidence interval: 0.28-0.79] to 0.60 [95% confidence interval: 0.44-0.82]) when compared with another active intervention. The methodological quality of most reviews (n = 16/18; 84%) was low or critically low and strength of evidence was generally weak.

CONCLUSIONS

This review showed that the Mediterranean Diet can reduce fatal cardiovascular disease outcome risk by 10%-67% and non-fatal cardiovascular disease outcome risk by 21%-70%. This preventive effect was more significant in studies that included populations with established cardiovascular disease. Better quality reviews are needed.

The effects of Mediterranean diet on cardiovascular risk factors, glycemic control and weight loss in patients with type 2 diabetes: a meta-analysis

To explore the impact of the Mediterranean diet on cardiovascular risk factors, glycemic control and weight loss in patients with type 2 diabetes(T2D) by a meta-analysis of randomized controlled trials (RCTs). We systematically searched PubMed, Cochrance Library, EMBASE and four Chinese databases to identify RCTs that compared the Mediterranean diet with control diets in patients with T2D up to December 2021. The Risk of Bias of the included studies was assessed using the version 2 of the Cochrane risk-of-bias tools for randomized trials (ROB 2). Seven RCTs with 1371 patients met the eligibility criteria and entered into the meta-analysis. Compared to control diets, the beneficial effects of Mediterranean diet were not statistically significant in high-density lipoprotein (MD = 2.33; 95% CI: -0.27 to 4.92), low-density lipoprotein (MD = -2.34; 95% CI -5.67 to 0.99) and total cholesterol (MD = 2.60; 95% CI: -0.95 to 6.15). But Mediterranean diet led to reduce the level of diastolic blood pressure (MD = -1.20; 95% CI: -2.21 to -0.19) and systolic blood pressure (MD = -4.17; 95% CI: -7.12 to -1.22). Meanwhile, Mediterranean diet showed beneficial effects in glycemic control (HbA1[%]: MD = -0.39, 95% CI: -0.58 to -0.20; fasting plasma glucose: MD = -15.12, 95% CI: -24.69 to -5.55) and weight loss (BMI: MD = -0.71, 95% CI: -1.30 to -0.78; WC: MD = -1.69; 95% CI: -3.35 to -0.02) compared to the control diets. The meta-analysis presented evidence supporting the beneficial effects of the Mediterranean diet on blood pressure, glycemic control, and weight loss. However, the impact of the Mediterranean diet on the lipid profile was not found to be significant, warranting further verification. This Meta-analysis was registered on the INPLASY website (Registration number: INPLASY 202160096).

A Mediterranean-Style Diet Improves the Parameters for the Management and Prevention of Type 2 Diabetes Mellitus

Background and Objectives: Type 2 diabetes mellitus (T2DM) is a chronic condition recognized as the inability to maintain glucose homeostasis, typically presenting with insulin resistance and systemic inflammation. With the prevalence of T2DM and major risk factors, such as prediabetes and obesity, increasing each year, the need to address risk factor reduction strategies is crucial. Materials and Methods: Twenty-two men and women, overweight-to-obese adults (BMI mean: 26.1-31.6) (age range mean: 44.6-51.8) with T2DM, indicators of prediabetes, or who were metabolically healthy, participated in Cal Poly's Nutrition and Exercise in Type 2 Diabetes (CPNET) study. There were no significant differences in terms of age, BMI, or sex distribution among the groups at the baseline. This study's protocol included following a Mediterranean-style diet, the daily consumption of a high-quality whey protein supplement, and physical activity recommendations for 16 weeks. Body composition data, via dual-energy X-ray absorptiometry (DXA), and fasting blood samples were collected at the baseline and following the intervention. Due to restrictions associated with the outbreak of the COVID-19 pandemic, only 13 of the 22 participants who started this study were able to return for the second data collection to complete this study following the 16-week intervention. Results: The prediabetic and T2DM groups exhibited reductions in their fasting plasma glucose (12.0 mg/dL reduction in the prediabetic group; 19.6 mg/dL reduction in the T2DM group) to that of normal and prediabetic levels, respectively, while the T2DM group also demonstrated improvement in their hemoglobin A1c (reduced from 6.8% to 6.0%) to prediabetic levels. Additionally, the metabolically healthy, overweight group exhibited significant improvements in adiposity, while the obese prediabetic and T2DM groups showed non-significant improvements in all the measured metrics of body composition. No significant changes were observed in the inflammatory biomarkers (p-values ranged from 0.395 to 0.877). Conclusions: Collectively, our results suggest that adherence to a well-balanced, nutritious diet and activity may improve the parameters of glycemic control and provide benefits to body composition that help to manage and prevent the development of T2DM. Our study was able to yield significant findings signifying that the effects of a Mediterranean-style diet are observed even for a more conservative sample size.

Effect of Dietary Approaches on Glycemic Control in Patients with Type 2 Diabetes: A Systematic Review with Network Meta-Analysis of Randomized Trials

BACKGROUND

Dietary patterns play a critical role in diabetes management, while the best dietary pattern for Type 2 diabetes (T2DM) patients is still unclear. The aim of this network meta-analysis was to compare the impacts of various dietary approaches on the glycemic control of T2DM patients.

METHODS

Relevant studies were retrieved from PubMed, Embase, Web of Knowledge, Cochrane Central Register of Controlled Trials (CENTRAL), and other additional records (1949 to 31 July 2022). Eligible RCTs were those comparing different dietary approaches against each other or a control diet in individuals with T2DM for at least 6 months. We assessed the risk of bias of included studies with the Cochrane risk of bias tool and confidence of estimates with the Grading of Recommendations Assessment, Development, and Evaluation approach for network meta-analyses. In order to determine the pooled effect of each dietary approach relative to each other, we performed a network meta-analysis (NMA) for interventions for both HbA1c and fasting glucose, which enabled us to estimate the relative intervention effects by combing both direct and indirect trial evidence.

RESULTS

Forty-two RCTs comprising 4809 patients with T2DM were included in the NMA, comparing 10 dietary approaches (low-carbohydrate, moderate-carbohydrate, ketogenic, low-fat, high-protein, Mediterranean, Vegetarian/Vegan, low glycemic index, recommended, and control diets). In total, 83.3% of the studies were at a lower risk of bias or had some concerns. Findings of the NMA revealed that the ketogenic, low-carbohydrate, and low-fat diets were significantly effective in reducing HbA1c (viz., -0.73 (-1.19, -0.28), -0.69 (-1.32, -0.06), and -1.82 (-2.93, -0.71)), while moderate-carbohydrate, low glycemic index, Mediterranean, high-protein, and low-fat diets were significantly effective in reducing fasting glucose (viz., -1.30 (-1.92, -0.67), -1.26 (-2.26, -0.27), -0.95 (-1.51, -0.38), -0.89 (-1.60, -0.18) and -0.75 (-1.24, -0.27)) compared to a control diet. The clustered ranking plot for combined outcomes indicated the ketogenic, Mediterranean, moderate-carbohydrate, and low glycemic index diets had promising effects for controlling HbA1c and fasting glucose. The univariate meta-regressions showed that the mean reductions of HbA1c and fasting glucose were only significantly related to the mean weight change of the subjects.

CONCLUSIONS

For glycemic control in T2DM patients, the ketogenic diet, Mediterranean diet, moderate-carbohydrate diet, and low glycemic index diet were effective options. Although this study found the ketogenic diet superior, further high-quality and long-term studies are needed to strengthen its credibility.

Dietary Patterns and Non-Communicable Disease Biomarkers: A Network Meta-Analysis and Nutritional Geometry Approach

Quantitative rankings of multiple dietary patterns for their effects on non-communicable disease (NCD) biomarkers is lacking and would inform primary prevention strategies. Accordingly, a network meta-analysis (NMA) was conducted to compare and rank the effects of different dietary patterns on NCD biomarkers, and associations of dietary patterns’ underlying macronutrient composition with NCD biomarkers were determined by a nutritional geometry approach. Randomised controlled trials (RCTs) were eligible for inclusion if they enrolled healthy participants, employed food-based dietary pattern interventions without energy restriction, and reported NCD biomarker outcomes. NCD biomarkers were included as an outcome if ≥10 trials were available. A systematic search of five electronic databases identified 4008 records. Sixty-eight articles from 59 RCTs reporting lipids, glycemic, and inflammatory biomarkers were included for quantitative syntheses. Risk-of-bias was predominantly categorized as low or having some concerns, and confidence-of-evidence low. Relative to western habitual diet, the Mediterranean, Dietary Approaches to Stop Hypertension (DASH), dietary guidelines-based, plant-based, and low-fat diets reduced low-density lipoprotein cholesterol (mean difference range: −0.29 to −0.17 mmol/L), total cholesterol (−0.36 to −0.24 mmol/L), and apolipoprotein B (−0.11 to −0.07 g/L) (all p < 0.05); the Paleo, plant-based and dietary guidelines-based diets reduced homeostasis model assessment of insulin resistance (−0.95 to −0.35, all p < 0.05). No dietary pattern ranked consistently highest. The Paleo diet received the highest all-outcomes-combined average Surface Under the Cumulative Ranking Curve value (67%), followed by DASH (62%) and Mediterranean diets (57%), whereas western habitual diet was lowest (36%). Our findings were independent of macronutrient composition, highlighting the significance of dietary pattern-level analysis.

The short- and long-term effects of dietary patterns on cardiometabolic health in adults aged 65 years or older: a systematic review

CONTEXT

Cardiometabolic diseases are leading causes of death and morbidity. Aging increases the risk of disease development. Diet has protective and causal effects on cardiometabolic health.

OBJECTIVE

To consolidate the current evidence on the short- and long-term effects of dietary patterns on cardiometabolic health in adults aged ≥ 65 years.

DATA SOURCES

The Medline, Embase, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects, Cumulative Index to Nursing and Allied Health Literature, Web of Science, Scopus, Global Health, and Pre-Medline databases, along with ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform were searched.

DATA EXTRACTION

A total of 40 042 records were identified. Quality assessment involved using the revised Cochrane risk-of-bias tool for randomized trials and Joanna Briggs Institute checklists. The certainty of evidence was assessed using Grading of Recommendations, Assessment, Development, and Evaluation.

RESULTS

Thirteen articles were included (n = 5 cohort studies and n = 3 randomized controlled trials). The low-fat dietary pattern reduced adiposity; however, no effects were evident for hypertension incidence, composite coronary heart disease incidence (including myocardial infarction, coronary heart disease, and coronary revascularization), high-density lipoprotein cholesterol level, and increased blood pressure in the long term. The Mediterranean dietary pattern resulted in reduced triglyceride levels and systolic blood pressure, and had no effects on diastolic blood pressure and glucose in the short term. Other dietary patterns had inconclusive effects.

CONCLUSIONS

The Mediterranean dietary pattern showed the most benefits without harm on cardiometabolic health in older adults. The current body of evidence is small, indicating the need for more research to confirm these findings at a high certainty of evidence, and to include dietary patterns combined with other dietary components, subgroups with cardiometabolic disease or risk factors, longer follow-up, and outcomes that have not yet been investigated. Studies including these factors may help identify the most effective dietary pattern for cardiometabolic health benefits in older adults, to inform future guidelines.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42020141400.

An Artificial-Intelligence-Discovered Functional Ingredient, NRT_N0G5IJ, Derived from Pisum sativum, Decreases HbA1c in a Prediabetic Population

The prevalence of prediabetes is rapidly increasing, and this can lead to an increased risk for individuals to develop type 2 diabetes and associated diseases. Therefore, it is necessary to develop nutritional strategies to maintain healthy glucose levels and prevent glucose metabolism dysregulation in the general population. Functional ingredients offer great potential for the prevention of various health conditions, including blood glucose regulation, in a cost-effective manner. Using an artificial intelligence (AI) approach, a functional ingredient, NRT_N0G5IJ, was predicted and produced from Pisum sativum (pea) protein by hydrolysis and then validated. Treatment of human skeletal muscle cells with NRT_N0G5IJ significantly increased glucose uptake, indicating efficacy of this ingredient in vitro. When db/db diabetic mice were treated with NRT_N0G5IJ, we observed a significant reduction in glycated haemoglobin (HbA1c) levels and a concomitant benefit on fasting glucose. A pilot double-blinded, placebo controlled human trial in a population of healthy individuals with elevated HbA1c (5.6% to 6.4%) showed that HbA1c percentage was significantly reduced when NRT_N0G5IJ was supplemented in the diet over a 12-week period. Here, we provide evidence of an AI approach to discovery and demonstrate that a functional ingredient identified using this technology could be used as a supplement to maintain healthy glucose regulation.

Mediterranean Diet and Type 2 Diabetes Mellitus: A Perpetual Inspiration for the Scientific World. A Review

For the past 80 years, the effect of the Mediterranean diet on overall health has been a constant topic of interest among medical and scientific researchers. Parallel with the persistent global rise of cases of type 2 diabetes, many studies conducted in the past 20 years have shown the benefits of the Mediterranean lifestyle for people with, or at risk of developing, type 2 diabetes mellitus. However, despite the large body of evidence, concerns exist amongst scientists regarding the reliability of the data related to this topic. This review offers a glimpse of the onset of the Mediterranean diet and follows its significant impact on the prevention and treatment of type 2 diabetes. There is a constant rise in type 2 diabetes cases on the Balkan Peninsula and North Macedonia in particular. Having in mind that North Macedonia, as well as most of the countries on the Balkans have low to middle income, there is a need for a certain affordable dietary pattern to ameliorate the rise in diabetes incidence, as well as improve the glycemic control. We did a review based on the available literature regarding Mediterranean diet and people with or at risk of developing type 2 diabetes mellitus, its effects on glycemic control, lipid profile and metabolic outcome.

Mediterranean Diet Effects on Type 2 Diabetes Prevention, Disease Progression, and Related Mechanisms. A Review

The search for a quality diet has grown over the past decade. Diet is considered one of the pillars for the prevention and progression of several diseases, among them: diabetes. Type 2 diabetes (T2D) is an epidemic of western countries that increases the vulnerability of other diseases, such as cardiovascular and cancer. T2D is associated with lifestyle and diet. The traditional Mediterranean diet has proven its benefits over several cardiovascular risk factors, and specifically on diabetes. This review compiles recent published evidence on the effects of the Mediterranean diet on the incidence and progression of type 2 diabetes (T2D) and its relation with several other cardiovascular healthy diets. We will also focus on how the Mediterranean diet could play a role in T2D-related mechanisms, such as anti-inflammatory or antioxidant compounds, glucagon-like peptide agonist compounds, and changes in gut microbiota. Each component of the Mediterranean diet could be involved in processes related to diabetes homeostasis, many of them sharing common physio-pathological pathways. The importance of this diet within the set of habits of a healthy lifestyle must be emphasized.

Exploring the Diets of Adults with Obesity and Type II Diabetes from Nine Diverse Countries: Dietary Intakes, Patterns, and Quality

Background: Calorie-dense diet is a main driver of the global epidemics of obesity and type 2 diabetes (T2DM). While various dietary strategies and patterns are efficacious in reducing risk and improving glycemic control, dietary intake and diet quality have been inadequately studied among individuals who remain living in their native environments. There is also little published on dietary patterns of diverse ethnic, cultural, or regional populations. Objective: To explore dietary intakes, patterns and overall diet quality in adults with obesity and T2DM from diverse countries. We hypothesized that individuals sharing a common clinical phenotype (age, BMI, years since T2DM diagnosis and inadequate glycemic control) would demonstrate comparable high calorie “western” dietary patterns and low diet quality despite differences in geographic regions and cultures. Design: Diet data were acquired from 611 adults in Argentina, Germany, Poland, Serbia, Slovakia, Slovenia, Spain, Turkey and the USA via three 24-h diet recalls. Contribution of 168 foods to 14 primary food groups was confirmed by Spearman’s rank-order correlations and Principle Component Factor Analysis identified dietary patterns. Diet quality was assessed using the Healthy Eating Index 2015. Results: Eleven dietary patterns were extracted; the most common were a “Mediterranean-like” pattern shared by six countries and a “Calorie Dense” pattern shared by five countries. Also common were “Lacto-Vegetarian, “Pesco-Vegetarian,” and “Vegan” patterns. Only 2.1% of subjects had good diet quality (HEI-2015 score >80). Conclusions: The diet pattern data suggest that influences of more traditional region-specific diets remain. However, overall diet quality was poor and may contribute to inadequate glycemic control, possibly due to excess intake of high calorie/nutrient poor foods, which may be associated with global transitions occurring in the available food supply.

Scoping review of Paleolithic dietary patterns: a definition proposal

The Paleolithic diet (PaleoDiet) is an allegedly healthy dietary pattern inspired by the consumption of wild foods and animals assumed to be consumed in the Paleolithic era. Despite gaining popularity in the media, different operational definitions of this Paleolithic nutritional intake have been used in research. Our hypothesis is that specific components used to define the PaleoDiet may modulate the association of this diet with several health outcomes. We comprehensively reviewed currently applied PaleoDiet scores and suggested a new score based on the food composition of current PaleoDiet definitions and the theoretical food content of a staple dietary pattern in the Paleolithic age. In a PubMed search up to December 2019, fourteen different PaleoDiet definitions were found. We observed some common components of the PaleoDiet among these definitions although we also found high heterogeneity in the list of specific foods that should be encouraged or banned within the PaleoDiet. Most studies suggest that the PaleoDiet may have beneficial effects in the prevention of cardiometabolic diseases (type 2 diabetes, overweight/obesity, CVD and hyperlipidaemias) but the level of evidence is still weak because of the limited number of studies with a large sample size, hard outcomes instead of surrogate outcomes and long-term follow-up. Finally, we propose a new PaleoDiet score composed of eleven food items, based on a high consumption of fruits, nuts, vegetables, fish, eggs and unprocessed meats (lean meats); and a minimum content of dairy products, grains and cereals, and legumes and practical absence of processed (or ultra-processed) foods or culinary ingredients.

An Update on the Mediterranean, Vegetarian, and DASH Eating Patterns in People With Type 2 Diabetes

When it comes to eating, there is no "one-size-fits-all" solution. This article provides an overview of recommendations and research for three evidence-based eating patterns-Mediterranean, DASH (Dietary Approaches to Stop Hypertension), and vegetarian/vegan-that can be individualized for people with type 2 diabetes. In an effort to improve adherence and health outcomes, practical considerations for improving nutrition are highlighted with the aim of helping patients successfully adopt an eating pattern that meets their individual needs and sociocultural and personal preferences.

Dietary Patterns Emphasizing the Consumption of Plant Foods in the Management of Type 2 Diabetes: A Narrative Review

The prevalence of type 2 diabetes (T2D) is increasing worldwide. This complex and multifactorial metabolic condition affects both the quality and expectancy of life in adults. Therefore, appropriate lifestyle strategies are needed in order to reduce the burden of T2D. Dietary patterns characterized by a high consumption of fruits, vegetables, whole grains, legumes, nuts, and seeds, and a minimal consumption of animal products, have been suggested as a dietary approach to prevent and control T2D and related micro- and macrovascular complications. This narrative review summarizes epidemiologic and clinical trial evidence on the role of the most widely studied dietary patterns that emphasize the consumption of plant foods [vegetarian, vegan, Mediterranean, and DASH (Dietary Approaches to Stop Hypertension) diets] in the management of T2D and its complications. Furthermore, their potential underlying mechanisms are discussed. Dietary patterns emphasizing the consumption of plant foods appear to confer beneficial effects on glycemic control in different diabetic populations. Several components of these dietary patterns might confer benefits on glycemia and counterbalance the detrimental effects of animal-based foods. The limited evidence on T2D-related complications makes it difficult to draw solid conclusions.

Perspective: Network Meta-analysis Reaches Nutrition Research: Current Status, Scientific Concepts, and Future Directions

Traditional pairwise meta-analysis (PMA) is a very useful method that pools evidence from one study design type if appropriate; its widespread use in nutrition research is an important phenomenon. Recently, a promising method for more advanced evidence-synthesis, called network meta-analysis (NMA), was introduced. NMA is an extension of PMA that enables simultaneous comparison of multiple interventions. NMA combines direct evidence (i.e., trials comparing 2 interventions directly) and indirect evidence (i.e., from a connected route via ≥1 comparators, e.g. placebo) in a network of studies. NMAs have the potential to advance knowledge in the field of nutrition as they provide insights that cannot be obtained by individual 2-arm randomized controlled trials or PMA. Thus, in this perspective paper, we aim to summarize the current (methodologic) status of published NMAs in nutrition research and emphasize advances and strengths in comparison with traditional PMA through specific examples, and highlight potential pitfalls and limitations. NMA is an emerging methodology in the field of nutrition research. A PubMed search identified only 23 nutrition research-related NMAs published since the inception of journals up to January 8, 2019 (61% of them published since 2017), compared with >5000 published PMAs. Moreover, we aim to highlight the scientific concepts and standards through the use of the following NMA example: "Which type of oils/solid fats offers the greatest impact on blood lipids?" In this regard, we discuss intervention definitions, transitivity/similarity, statistical methods, description and visualization of results, inconsistency, ranking, dissemination bias, assessing the certainty of evidence by Grading of Recommendations Assessment, Development and Evaluation, and reporting guidelines. We expect that rigorously conducted NMAs based on high-quality systematic reviews will become the new evidence synthesis benchmark in nutrition research. However, caution is warranted because abuse and misinterpretations of PMA and NMA findings could hamper the scientific field and possibly decision-making regarding public policy.

The Mediterranean Diet: From an Environment-Driven Food Culture to an Emerging Medical Prescription

The Mediterranean diet originates in the food cultures of ancient civilizations which developed around the Mediterranean Basin and is based on the regular consumption of olive oil (as the main source of added fat), plant foods (cereals, fruits, vegetables, legumes, tree nuts, and seeds), the moderate consumption of fish, seafood, and dairy, and low-to-moderate alcohol (mostly red wine) intake, balanced by a comparatively limited use of red meat and other meat products. A few decades ago, the Mediterranean diet drew the attention of medical professionals by proving extended health benefits. The first reports ascertained cardiovascular protection, as multiple large-scale clinical studies, starting with Ancel Keys' Seven Countries Study, showed a marked reduction of atherosclerotic clinical events in populations with a Mediterranean dietary pattern. Ensuing trials confirmed favorable influences on the risk for metabolic syndrome, obesity, type 2 diabetes mellitus, cancer, and neurodegenerative diseases. While its health benefits are universally recognized today by medical professionals, the present state of the Mediterranean diet is challenged by major difficulties in implementing this protective dietary pattern in other geographical and cultural areas and keeping it alive in traditional Mediterranean territories, also tainted by the unhealthy eating habits brought by worldwide acculturation.

The impact of major dietary patterns on glycemic control, cardiovascular risk factors, and weight loss in patients with type 2 diabetes: A network meta-analysis

OBJECTIVE

To comprehensively compare the differences between major dietary patterns in improving glycemic control, cardiovascular risk, and weight loss for patients with type 2 diabetes.

METHOD

We systematically searched PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials (CENTRAL) to identify randomized controlled trials (RCTs) that compared the efficacy of Mediterranean, low-carbohydrate, and/or low-fat dietary patterns for patients with type 2 diabetes. Studies that compared any one of those diets with regular diet were also included. The risk of bias in eligible RCTs was evaluated according to the Cochrane Handbook. The primary outcome was glycemic control. Secondary outcomes included weight loss and cardiovascular risk factors. A network meta-analysis was performed using R-3.3.2.

RESULTS

Ten RCTs involving five dietary patterns met the eligibility criteria. The findings revealed that compared to low-fat diet, Mediterranean diet showed beneficial effects in glycemic control (HbA1c [%]: MD = -0.45, 95% CI = -0.55 to -0.34; fasting plasma glucose [mmol/L]: MD = -1.24 95% CI = -1.57 to -0.91, respectively; weight loss [kg]: MD =-1.18, 95% CI = -1.99 to -0.37; waist circumference [cm]: MD = -0.73, 95% CI = -1.26 to -0.19), and cardiovascular risk factors (HDL-cholesterol [mmol/L]: MD = 0.07, 95% CI = 0.04 to 0.11; total cholesterol [mmol/L]: MD = -0.17, 95% CI = -0.26 to -0.08; triglycerides [mmol/L]: MD = -0.21, 95% CI = -0.27 to -0.16). Network meta-analysis showed that high-carbohydrate diet improved HDL-cholesterol (mmol/l) (MD = 1.04, 95% CI = 0.39 to 1.68) when compared with regular diet. The differences were not statistically significant in other indirect comparison groups for other outcomes.

CONCLUSIONS

A mediterranean diet showed beneficial improvements in glycemic control, weight loss, and cardiovascular risk factors in people with type 2 diabetes.

Sleep duration, obesity and insulin resistance in a multi-ethnic UK population at high risk of diabetes

AIMS

Investigating the association between sleep duration, obesity, adipokines and insulin resistance (via Leptin:Adiponectin ratio (LAR)), in those at high risk of type 2 diabetes mellitus (T2DM).

METHODS

Adults with impaired glucose regulation (IGR) were included. Fasting bloods for inflammatory biomarkers and glycaemic status, 2-h glucose, anthropometrics, objective physical activity, and self-reported sleep were collected. The average number of hours slept in a 24 h period was categorised as ≤5.5, 6-6.5, 7-7.5, 8-8.5, and ≥9 h. Regression models were fitted with sleep (linear and quadratic) and logistic regression used for IGR and adjusted for age, sex, ethnicity, body mass index, waist circumference and objective physical activity.

RESULTS

2848 participants included (593 with inflammatory marker data). Short sleep and long sleep duration were significantly independently associated with higher body mass index (P < 0.001), body weight (P < 0.01), and waist circumference (P < 0.001). 6-7 h of sleep/24 h is associated with the lowest obesity measures. Fasting insulin and LAR were positively associated with sleep duration. Adiponectin levels were negatively associated with sleep duration.

CONCLUSIONS

These results support the evidence of an association between short and long sleep duration and indices of obesity. We demonstrate an independent relationship between long sleep duration and insulin resistance.

A network meta-analysis on the comparative efficacy of different dietary approaches on glycaemic control in patients with type 2 diabetes mellitus

The aim of the present study is to assess the comparative efficacy of different dietary approaches on glycaemic control in patients with type 2 diabetes mellitus using a systematic review of the literature. Electronic and hand searches were performed until July 2017. The inclusion criteria were defined as follows: (1) randomized trial with a dietary approach; (2) adults with type 2 diabetes mellitus; (3) outcome either HbA1c (%) and/or fasting glucose (mmol/l); (4) minimum intervention period of 12 weeks. For each outcome measure, random effects network meta-analysis was performed in order to determine the pooled effect of each intervention relative to each of the other interventions. A total of 56 trials comparing nine dietary approaches (low-fat, Vegetarian, Mediterranean, high-protein, moderate-carbohydrate, low-carbohydrate, control, low GI/GL, Palaeolithic) enrolling 4937 participants were included. For reducing HbA1c, the low-carbohydrate diet was ranked as the best dietary approach (SUCRA: 84%), followed by the Mediterranean diet (80%) and Palaeolithic diet (76%) compared to a control diet. For reducing fasting glucose, the Mediterranean diet (88%) was ranked as the best approach, followed by Palaeolithic diet (71%) and Vegetarian diet (63%). The network analysis also revealed that all dietary approaches significantly reduce HbA1c (− 0.82 to − 0.47% reduction) and fasting glucose (− 1.61 to − 1.00 mmol/l reduction) compared to a control diet. According to the network meta-analysis the Mediterranean diet is the most effective and efficacious dietary approach to improve glycaemic control in type 2 diabetes patients.

Mediterranean diet for type 2 diabetes: cardiometabolic benefits

Dietary patterns influence various cardiometabolic risk factors, including body weight, lipoprotein concentrations, and function, blood pressure, glucose-insulin homeostasis, oxidative stress, inflammation, and endothelial health. The Mediterranean diet can be described as a dietary pattern characterized by the high consumption of plant-based foods, olive oil as the main source of fat, low-to-moderate consumption of fish, dairy products and poultry, low consumption of red and processed meat, and low-to-moderate consumption of wine with meals. The American Diabetes Association and the American Heart Association recommend Mediterranean diet for improving glycemic control and cardiovascular risk factors in type 2 diabetes. Prospective studies show that higher adherence to the Mediterranean diet is associated with a 20-23 % reduced risk of developing type 2 diabetes, while the results of randomized controlled trials show that Mediterranean diet reduces glycosylated hemoglobin levels by 0.30-0.47 %, and is also associated with a 28-30 % reduced risk for cardiovascular events. The mechanisms by which Mediterranean diet produces its cardiometabolic benefits in type 2 diabetes are, for the most, anti-inflammatory and antioxidative: increased consumption of high-quality foods may cool down the activation of the innate immune system, by reducing the production of proinflammatory cytokines while increasing that of anti-inflammatory cytokines. This may favor the generation of an anti-inflammatory milieu, which in turn may improve insulin sensitivity in the peripheral tissues and endothelial function at the vascular level and ultimately act as a barrier to the metabolic syndrome, type 2 diabetes and development of atherosclerosis.

Diet and Diabetic Kidney Disease: Plant Versus Animal Protein

PURPOSE OF REVIEW

The goal of this review is to present an overview of the evidence on the effectiveness of plant-based diets in delaying progression of diabetic kidney disease (DKD).

RECENT FINDINGS

The ideal quantity of dietary protein has been a controversial topic for patients with DKD. Smaller studies have focused on protein source, plant versus animal, for preventing progression. Limited evidence suggests that dietary patterns that focus on plant-based foods, those that are lower in processed foods, or those that are lower in advanced glycation end products (AGE) may be useful in prevention of DKD progression. Increasing plant-based foods, incorporating diet patterns that limit processed foods, or potentially lowering AGE contents in diets may be beneficial for dietary management of DKD. However, dietary studies specifically targeted at DKD treatment are sparse. Further, large trials powered to assess outcomes including changes in kidney function, end-stage kidney disease, and mortality are needed to provide more substantial evidence for these diets.

Maladaptive Eating Behaviors and Metabolic Profile in Patients Submitted to Bariatric Surgery: a Longitudinal Study

PURPOSE

This study aims to investigate relations between maladaptive eating behaviors (MEB) and metabolic profile in patients submitted to bariatric surgery.

METHODS

Longitudinal study including 70 patients before (T0), in the first year after surgery assessment (T1), and the second year after surgery assessment (T2). A face-to-face clinical interview assessed MEB at T0 and T2. Blood samples were collected at T0, T1, and T2 to assess fasting plasma glucose (FPG), glycated hemoglobin (HbA1c), insulin, insulin resistance (IR), and triglycerides (TG). Mixed model analyses with growth curves tested the differences between patients with MEB (M group) and non-MEB patients (NM group) on the course of metabolic parameters, while controlling for total weight loss and type of surgery.

RESULTS

No differences between both groups were reached for levels of FPG (F(1, 140) = 2.936, p = 0.089), HbA1c (F(1, 96) = 0.099, p = 0.754), insulin (F(1, 121) = 0.146, p = 0.703), IR (F(1, 60) = 0.976, p = 0.327), and TG (F(1, 128) = 0.725, p = 0.396). All parameters improved from T0 to T1 for both groups. A distinct trend on the course of metabolic markers in the M group but not the NM group is observed, presenting an increase in HbA1c levels, insulin, and TG levels.

CONCLUSIONS

Both groups progressed favorably in the first 12 months of surgery. MEB may be associated with a trend for deterioration of metabolic profile after 12 months of surgery. The study should be replicated with longer-term assessments and a larger sample size.

Palaeolithic diet decreases fasting plasma leptin concentrations more than a diabetes diet in patients with type 2 diabetes: a randomised cross-over trial

Background

We have previously shown that a Palaeolithic diet consisting of the typical food groups that our ancestors ate during the Palaeolithic era, improves cardiovascular disease risk factors and glucose control compared to the currently recommended diabetes diet in patients with type 2 diabetes. To elucidate the mechanisms behind these effects, we evaluated fasting plasma concentrations of glucagon, insulin, incretins, ghrelin, C-peptide and adipokines from the same study.

Methods

In a randomised, open-label, cross-over study, 13 patients with type 2 diabetes were randomly assigned to eat a Palaeolithic diet based on lean meat, fish, fruits, vegetables, root vegetables, eggs and nuts, or a diabetes diet designed in accordance with current diabetes dietary guidelines during two consecutive 3-month periods. The patients were recruited from primary health-care units and included three women and 10 men [age (mean ± SD) 64 ± 6 years; BMI 30 ± 7 kg/m²; diabetes duration 8 ± 5 years; glycated haemoglobin 6.6 ± 0.6 % (57.3 ± 6 mmol/mol)] with unaltered diabetes treatment and stable body weight for 3 months prior to the start of the study. Outcome variables included fasting plasma concentrations of leptin, adiponectin, adipsin, visfatin, resistin, glucagon, insulin, C-peptide, glucose-dependent insulinotropic polypeptide, glucagon-like peptide-1 and ghrelin. Dietary intake was evaluated by use of 4-day weighed food records.

Results

Seven participants started with the Palaeolithic diet and six with the diabetes diet. The Palaeolithic diet resulted in a large effect size (Cohen’s d = −1.26) at lowering fasting plasma leptin levels compared to the diabetes diet [mean difference (95 % CI), −2.3 (−5.1 to 0.4) ng/ml, p = 0.023]. No statistically significant differences between the diets for the other variables, analysed in this study, were observed.

Conclusions

Over a 3-month study period, a Palaeolithic diet resulted in reduced fasting plasma leptin levels, but did not change fasting levels of insulin, C-peptide, glucagon, incretins, ghrelin and adipokines compared to the currently recommended diabetes diet.

Trial registration: ClinicalTrials.gov NCT00435240

Electronic supplementary material

The online version of this article (doi:10.1186/s12933-016-0398-1) contains supplementary material, which is available to authorized users.

On-chip, aptamer-based sandwich assay for detection of glycated hemoglobins via magnetic beads

Diabetes can be diagnosed and monitored by measurement of the cutoff ratio between glycated hemoglobins (HbA1c) and total hemoglobin (Hb), which does not require a fasting blood sample and is less influenced by biological variations. In this study, we combined the advantages of the microfluidic system and the selected low-cost, stable and specific aptamers and developed an integrated, aptamer-based microfluidic system for automatic glycated hemoglobin measurements. The detection process of human whole blood can be totally automated in this integrated microfluidic system. According to the experimental results, when compared to conventional bench-top manual assays, reagent consumption was significantly reduced by 75%, and the analysis time was reduced from 3.5h to 30 min. Besides, the novelty in this research also lies in the simultaneously performed two parallel assays for detection of Hb and HbA1c in a single chip. Therefore, this sensitive and low-cost aptamer-based microfluidic system may become a promising tool for point-of -care diagnosis of diabetes.

Type 2 diabetes: cost-effectiveness of medication adherence and lifestyle interventions

INTRODUCTION

Type 2 diabetes is a major burden for the payer, however, with proper medication adherence, diet and exercise regime, complication occurrence rates, and consequently costs can be altered.

AIMS

The aim of this study was to conduct a cost-effectiveness analysis on real patient data and evaluate which medication adherence or lifestyle intervention is less cost demanding for the payer.

METHODS

Medline was searched systematically for published type 2 diabetes interventions regarding medication adherence and lifestyle in order to determine their efficacies, that were then used in the cost-effectiveness analysis. For cost-effectiveness analysis-required disease progression simulation, United Kingdom Prospective Diabetes Study Outcomes model 2.0 and Slovenian type 2 diabetes patient cohort were used. The intervention duration was set to 1, 2, 5, and 10 years. Complications and drug costs in euro (EUR) were based on previously published type 2 diabetes costs from the Health Care payer perspective in Slovenia.

RESULTS

Literature search proved the following interventions to be effective in type 2 diabetes patients: medication adherence, the Mediterranean diet, aerobic, resistance, and combined exercise. The long-term simulation resulted in no payer net savings. The model predicted following quality-adjusted life-years (QALY) gained and incremental costs for QALY gained (EUR/QALYg) after 10 years of intervention: high-efficacy medication adherence (0.245 QALY; 9,984 EUR/QALYg), combined exercise (0.119 QALY; 46,411 EUR/QALYg), low-efficacy medication adherence (0.075 QALY; 30,967 EUR/QALYg), aerobic exercise (0.069 QALY; 80,798 EUR/QALYg), the Mediterranean diet (0.057 QALY; 27,246 EUR/QALYg), and resistance exercise (0.050 QALY; 111,847 EUR/QALYg).

CONCLUSION

The results suggest that medication adherence intervention is, regarding cost-effectiveness, superior to diet and exercise interventions from the payer perspective. However, the latter could also be utilized by patients without additional costs, but medication adherence intervention requires trained personnel because of its complex structure. Interventions should be performed for >2 years to produce noticeable health/cost results.

A journey into a Mediterranean diet and type 2 diabetes: a systematic review with meta-analyses

OBJECTIVES

To summarise the evidence about the efficacy of a Mediterranean diet on the management of type 2 diabetes and prediabetic states.

DESIGN

A systematic review of all meta-analyses and randomised controlled trials (RCTs) that compared the Mediterranean diet with a control diet on the treatment of type 2 diabetes and prediabetic states was conducted. Electronic searches were carried out up to January 2015. Trials were included for meta-analyses if they had a control group treated with another diet, if they were of sufficient duration (at least 6 months), and if they had at least 30 participants in each arm. A random-effect model was used to pool data.

PARTICIPANTS

Adults with or at risk for type 2 diabetes.

INTERVENTIONS

Dietary patterns that described themselves as using a 'Mediterranean' dietary pattern.

OUTCOME MEASURES

The outcomes were glycaemic control, cardiovascular risk factors and remission from the metabolic syndrome.

RESULTS

From 2824 studies, 8 meta-analyses and 5 RCTs were eligible. A 'de novo' meta-analysis of 3 long-term (>6 months) RCTs of the Mediterranean diet and glycaemic control of diabetes favoured the Mediterranean diet as compared with lower fat diets. Another 'de novo' meta-analysis of two long-term RCTs showed a 49% increased probability of remission from the metabolic syndrome. 5 meta-analyses showed a favourable effect of the Mediterranean diet, as compared with other diets, on body weight, total cholesterol and high-density lipoprotein cholesterol. 2 meta-analyses demonstrated that higher adherence to the Mediterranean diet reduced the risk of future diabetes by 19-23%.

CONCLUSIONS

The Mediterranean diet was associated with better glycaemic control and cardiovascular risk factors than control diets, including a lower fat diet, suggesting that it is suitable for the overall management of type 2 diabetes.

Network meta-analysis of multiple outcome measures accounting for borrowing of information across outcomes

Background

Network meta-analysis (NMA) enables simultaneous comparison of multiple treatments while preserving randomisation. When summarising evidence to inform an economic evaluation, it is important that the analysis accurately reflects the dependency structure within the data, as correlations between outcomes may have implication for estimating the net benefit associated with treatment. A multivariate NMA offers a framework for evaluating multiple treatments across multiple outcome measures while accounting for the correlation structure between outcomes.

Methods

The standard NMA model is extended to multiple outcome settings in two stages. In the first stage, information is borrowed across outcomes as well across studies through modelling the within-study and between-study correlation structure. In the second stage, we make use of the additional assumption that intervention effects are exchangeable between outcomes to predict effect estimates for all outcomes, including effect estimates on outcomes where evidence is either sparse or the treatment had not been considered by any one of the studies included in the analysis. We apply the methods to binary outcome data from a systematic review evaluating the effectiveness of nine home safety interventions on uptake of three poisoning prevention practices (safe storage of medicines, safe storage of other household products, and possession of poison centre control telephone number) in households with children. Analyses are conducted in WinBUGS using Markov Chain Monte Carlo (MCMC) simulations.

Results

Univariate and the first stage multivariate models produced broadly similar point estimates of intervention effects but the uncertainty around the multivariate estimates varied depending on the prior distribution specified for the between-study covariance structure. The second stage multivariate analyses produced more precise effect estimates while enabling intervention effects to be predicted for all outcomes, including intervention effects on outcomes not directly considered by the studies included in the analysis.

Conclusions

Accounting for the dependency between outcomes in a multivariate meta-analysis may or may not improve the precision of effect estimates from a network meta-analysis compared to analysing each outcome separately.

A healthy diet with and without cereal grains and dairy products in patients with type 2 diabetes: study protocol for a random-order cross-over pilot study--Alimentation and Diabetes in Lanzarote--ADILAN

Background

Research on the role of nutrition in type 2 diabetes has largely focused on macro/micronutrient composition and dietary fiber intake, while fewer studies have tested the effects of differing food choice. Some observational studies and short-term intervention studies suggest that a food pattern mimicking the diet with which humans evolved positively influences glucose control and associated endocrine systems. Such a food pattern mainly differs from other common healthy food patterns in its absence of cereal grains and dairy products. The primary aim of this pilot study is to determine the effect of two healthy diets with or without cereal grains and dairy products on glucose control, while keeping participants’ weight stable and other food parameters, such as macro/micronutrient composition, dietary fiber and glycemic load, the same in both diets.

Methods/Design

We intend to include 15 adult patients with a medical diagnosis of type 2 diabetes mellitus with or without medication and with an increased waist circumference (≥ 80 cm for women and ≥ 94 cm for men) in a random-order cross-over diet intervention study during two periods of four-weeks separated by a six-week washout period. Patients will be instructed to eat two healthy diets according to official dietary guidelines with respect to macro/micronutrient composition and fiber content, but differing in the type of food included, with one diet being without cereal grains and dairy products. Lunch will be served in a hospital kitchen for control of nutrient intake, while the rest of the meals will be eaten at home according to specific directions. The energy content of the diets will be individually adjusted to maintain a stable body weight during the two four-week intervention periods. Primary outcomes will be change in fasting plasma glucagon and fructosamine, while secondary outcomes include change in fasting glucose and glycated hemoglobin, glucose and glucagon response during oral glucose tolerance test, blood lipids, blood pressure, C-reactive protein, body composition, quality of life, subjective experience with the two diets, satiety scores and changes in medication.

Discussion

Using these results, we will assess the need to conduct larger and longer studies with similar design.

Trial registration

This trial was registered at clinicaltrials.gov as NCT01891955 and Spanish Agency of Medication and Sanitary Products (AEMPS) registration code: MFV-ADI-2013-01.