Nutrition in Type 2 Diabetes and the Metabolic Syndrome

Neuropathy and the metabolic syndrome

Obesity and the metabolic syndrome (MetS) are major global health challenges that contribute significantly to the rising prevalence of type 2 diabetes (T2D) and neuropathy. Neuropathy, a common and disabling complication of T2D, is characterized by progressive distal-to-proximal axonal degeneration, driven in part by mitochondrial dysfunction in both neurons and axons. Recent evidence points to the toxic effects of saturated fatty acids on peripheral nerve health, with studies demonstrating that these fats impair mitochondrial function and bioenergetics, leading to distal axonal loss. Conversely, monounsaturated fatty acids are found to be neuroprotective, restoring mitochondrial function and preventing neuropathy. These findings suggest that dietary factors play a crucial role in the pathogenesis of neuropathy associated with metabolic dysregulation and emphasize the need for lifestyle interventions and therapies that target these newly identified mechanisms.

Determining classes of food items for health requirements and nutrition guidelines using Gaussian mixture models

Introduction

The identification of classes of nutritionally similar food items is important for creating food exchange lists to meet health requirements and for informing nutrition guidelines and campaigns. Cluster analysis methods can assign food items into classes based on the similarity in their nutrient contents. Finite mixture models use probabilistic classification with the advantage of taking into account the uncertainty of class thresholds.

Methods

This paper uses univariate Gaussian mixture models to determine the probabilistic classification of food items in the South African Food Composition Database (SAFCDB) based on nutrient content.

Results

Classifying food items by animal protein, fatty acid, available carbohydrate, total fibre, sodium, iron, vitamin A, thiamin and riboflavin contents produced data-driven classes with differing means and estimates of variability and could be clearly ranked on a low to high nutrient contents scale. Classifying food items by their sodium content resulted in five classes with the class means ranging from 1.57 to 706.27 mg per 100 g. Four classes were identified based on available carbohydrate content with the highest carbohydrate class having a mean content of 59.15 g per 100 g. Food items clustered into two classes when examining their fatty acid content. Foods with a high iron content had a mean of 1.46 mg per 100 g and was one of three classes identified for iron. Classes containing nutrient-rich food items that exhibited extreme nutrient values were also identified for several vitamins and minerals.

Discussion

The overlap between classes was evident and supports the use of probabilistic classification methods. Food items in each of the identified classes were comparable to allowed food lists developed for therapeutic diets. This data-driven ranking of nutritionally similar classes could be considered for diet planning for medical conditions and individuals with dietary restrictions.

Protective effect of manganese treatment on insulin resistance in HepG2 hepatocytes

Introduction

Objectives: manganese (Mn) is closely related to type 2 diabetes mellitus and insulin resistance (IR), but the exact mechanism is unclear. This study aimed to explore the regulatory effects and mechanism of Mn on IR using hepatocyte IR model induced by high palmitate (PA), high glucose (HG) or insulin. Methods: HepG2 cells were exposed to PA (200 μM), HG (25 mM) or insulin (100 nM) respectively, alone or with 5 μM Mn for 24 hours. The expression of key proteins in insulin signaling pathway, intracellular glycogen content and glucose accumulation, reactive oxygen species (ROS) level and Mn superoxide dismutase (MnSOD) activity were detected. Results: compared with control group, the expression of phosphorylated protein kinase B (Akt), glycogen synthase kinase-3β (GSK-3β) and forkhead box O1 (FOXO1) in the three IR groups was declined, and this decrease was reversed by Mn. The reduction of intracellular glycogen content and increase in glucose accumulation in IR groups were also inhibited by Mn. Additionally, the production of ROS was increased in IR models, compared with normal control group, while Mn reduced the excessive production of ROS induced by PA, HG or insulin. However, Mn did not alter the activity of MnSOD in the three IR models. Conclusion: this study demonstrated that Mn treatment can improve IR in hepatocytes. The mechanism is probably by reducing the level of intracellular oxidative stress, enhancing the activity of Akt/GSK-3β/FOXO1 signal pathway, promoting glycogen synthesis, and inhibiting gluconeogenesis.

Advancing human disease research with fish evolutionary mutant models

Model organism research is essential to understand disease mechanisms. However, laboratory-induced genetic models can lack genetic variation and often fail to mimic the spectrum of disease severity. Evolutionary mutant models (EMMs) are species with evolved phenotypes that mimic human disease. EMMs complement traditional laboratory models by providing unique avenues to study gene-by-environment interactions, modular mutations in noncoding regions, and their evolved compensations. EMMs have improved our understanding of complex diseases, including cancer, diabetes, and aging, and illuminated mechanisms in many organs. Rapid advancements of sequencing and genome-editing technologies have catapulted the utility of EMMs, particularly in fish. Fish are the most diverse group of vertebrates, exhibiting a kaleidoscope of specialized phenotypes, many that would be pathogenic in humans but are adaptive in the species' specialized habitat. Importantly, evolved compensations can suggest avenues for novel disease therapies. This review summarizes current research using fish EMMs to advance our understanding of human disease.

Carotenoid status in type 2 diabetes patients with and without retinopathy

Diabetic retinopathy (DR) is one of the leading causes of blindness. Carotenoids are plant-derived pigments required for general health and particularly for vision. In this study, we evaluated the dietary intake and blood carotenoid levels of type 2 diabetes (T2D) patients with and without DR. A cross-sectional case-control study was conducted among 151 age-matched controls and 344 T2D patients, of which 194 had DR and 150 had no DR (NDR). After a complete ophthalmic examination, the demographic, anthropometric and clinical profiles were obtained. Carotenoids in the plasma were measured by HPLC and dietary intakes were obtained using a food frequency questionnaire. The mean plasma levels of carotenoids (except γ-carotene) were significantly lower in the DR group compared to the Control and NDR groups. The dietary intakes of zeaxanthin, lycopene, α-carotene and β-carotene were significantly lower in the NDR group compared to the Control group, and were further lower in the DR group compared to the NDR group. Plasma carotenoid levels were significantly inversely associated with the duration of diabetes, RBS and HbA1c but positively associated with HDL. This study demonstrated decreased plasma levels and lower dietary intakes of carotenoids in DR subjects.

Influence of IGF2BP2, HMG20A, and HNF1B genetic polymorphisms on the susceptibility to Type 2 diabetes mellitus in Chinese Han population

Background: The present study aimed to investigate the roles of insulin related gene IGF2BP2, HMG20A, and HNF1B variants in the susceptibility of Type 2 diabetes mellitus (T2DM), and to identify their association with age, gender, BMI, and smoking and alcohol drinking behavior among the Han Chinese population.

Methods: About 508 patients with T2DM and 503 healthy controls were enrolled. Rs11927381 and rs7640539 in IGF2BP2, rs7178572 in HMG20A, rs4430796, and rs11651052 in HNF1B were genotyped by using the Agena MassARRAY. Odds ratio (OR) and 95% confidence intervals (CI) were calculated by logistic regression.

Results: We found that HMG20A rs7178572 (OR = 1.25, P = 0.015) and HNF1B rs11651052 (OR = 1.26, P = 0.019) increased the risk of T2DM. Rs7178572, rs4430796, and rs11651052 might be related to the higher T2DM susceptibility not only by itself but also by interacting with age, gender smoking, and alcohol drinking. Rs11927381 also conferred the higher T2DM susceptibility at age ≤ 59 years. Besides, rs7178572-AA (P = 0.032) genotype and rs11651052 GG (P = 0.018) genotype were related to higher glycated hemoglobin and insulin level, respectively.

Conclusion: Specifically, we first found that rs11927381, rs7640539, and rs11651052 were associated with risk of T2DM among the Han Chinese population. We also provide evidence that age, gender, BMI, smoking, and drinking status have an interactive effect with these variants on T2DM susceptibility.

Personal values in adolescence and their associations with metabolic biomarkers in adulthood: a Japanese population-based study

Background

Personal values, which are formed in early life, can have an impact on health outcome later in life.

Objective

The aim of this study is to investigate the relation between personal values in adolescence and bio-indicators related to metabolic syndrome (MetS) in adulthood.

Participants and Methods

The longitudinal data used was from the Japanese Study on Stratification, Health, Income, and Neighborhood (J-SHINE). Personal values in adolescence were retrospectively obtained in 2017 from a self-reporting questionnaire, composed of value priorities and commitment to the values. Venous samples were collected in 2012 for low and high-density lipoprotein (LDL, HDL) cholesterol and hemoglobin A1c (HbA1c). Body mass index (BMI), waist circumference and systolic and diastolic blood pressure (SBP, DBP) were also measured. The associations of each variable were examined by partial correlation analysis. In addition, multiple linear regression analysis was conducted to examine overall associations between personal values and the sum of standardized scores (Z-score) of the biomarkers as a proxy of MetS.

Results

The total population (n = 668) included 261 men and 407 women. For men, the personal value priority of “Having influence on society” was associated with high HDL cholesterol (0.133, p = 0.032) and “Cherishing familiar people” with low waist circumference (r = -0.129, p = 0.049), low SBP, and high DBP (r = -0.135, p = 0.039; r = 0.134, p = 0.041). For women, “Not bothering others” was associated with high SBP and low DBP (r = 0.125, p = 0.015; r = -0.123, p = 0.017). "Economically succeeding" was associated with a worse outcome (β = 0.162, p = 0.042) in men.

Conclusions

Although some significant associations were found between personal values in adolescence and MetS-related markers in adulthood, the overall associations were not strong. Culturally prevailing values were likely to be associated with a good outcome of metabolic health.

Dietary Fat and Risk for Type 2 Diabetes: a Review of Recent Research

Purpose of Review

It is estimated that over 400 million people worldwide are living with diabetes. Excess adiposity is the strongest risk factor for non-insulin-dependent diabetes, type 2. Lifestyle interventions have demonstrated that diet plays a critical role in preventing the onset of type 2 diabetes. Dietary fat is not only a source of energy and nutrients, but also bioactive fatty acids.

The purpose of this review was to examine data from recent prospective cohort studies and dietary interventions to determine if there are benefits to fat consumption on diabetes risk.

Recent Findings

The consumption of fish and marine n-3 fatty acids among Asian populations and regular-fat dairy foods and trans-palmitoleic acid (trans-16, n-7) among Western populations may be associated with reduced risk for type 2 diabetes.

Summary

Whereas some dietary fat may contribute to reduced diabetes risk, lifestyle recommendations to balance calories with physical activity are prudent at this time.

Total and Subtypes of Dietary Fat Intake and Its Association with Components of the Metabolic Syndrome in a Mediterranean Population at High Cardiovascular Risk

Background: The effect of dietary fat intake on the metabolic syndrome (MetS) and in turn on cardiovascular disease (CVD) remains unclear in individuals at high CVD risk. Objective: To assess the association between fat intake and MetS components in an adult Mediterranean population at high CVD risk. Design: Baseline assessment of nutritional adequacy in participants (n = 6560, men and women, 55-75 years old, with overweight/obesity and MetS) in the PREvención con DIeta MEDiterránea (PREDIMED)-Plus randomized trial. Methods: Assessment of fat intake (total fat, monounsatured fatty acids: MUFA, polyunsaturated fatty acids: PUFA, saturated fatty acids: SFA, trans-fatty acids: trans-FA, linoleic acid, α-linolenic acid, and ω-3 FA) using a validated food frequency questionnaire, and diet quality using 17-item Mediterranean dietary questionnaire and fat quality index (FQI). Results: Participants in the highest quintile of total dietary fat intake showed lower intake of energy, carbohydrates, protein and fiber, but higher intake of PUFA, MUFA, SFA, TFA, LA, ALA and ω-3 FA. Differences in MetS components were found according to fat intake. Odds (5th vs. 1st quintile): hyperglycemia: 1.3-1.6 times higher for total fat, MUFA, SFA and ω-3 FA intake; low high-density lipoprotein cholesterol (HDL-c): 1.2 higher for LA; hypertriglyceridemia: 0.7 lower for SFA and ω-3 FA intake. Conclusions: Dietary fats played different role on MetS components of high CVD risk patients. Dietary fat intake was associated with higher risk of hyperglycemia.

Effects of nutrition motivational intervention in patients affected by type 2 diabetes mellitus: a longitudinal study in Naples, South Italy

Background

Type 2 diabetes (T2D) is associated with a prion diminished quality of life, especially due to the severe complications that it implicates. Changing dietary habits is an absolute priority, as well as implementing nutritional motivational programs. The aim of this study was to verify the effectiveness of a nutritional intervention in improving the health of patients affected by T2D.

Methods

A total of 69 patients participated in a nine-months motivational program focused on the principles of the Mediterranean diet, the classes of nutrients, the distribution of the meals during the day and the dietary choices. During regular meetings, the patients were requested to fill out a questionnaire about their dietary habits and behaviours. Clinical and metabolic parameters were also analysed.

Results

At the end of the intervention the number of people who declared that they ate five meals a day (p = 0.006) and preferred to have fruit for snack (p = 0.004) increased, while there was a reduction in the use of sweeteners and an elimination of the use of fructose (p = 0.05). The total daily consumption of kilocalories (kcal) had been reduced and the percentages of carbohydrates, proteins and lipids, after the intervention, follow the guidelines. In relation to this, a significant improvement (p < 0.05) was registered in systolic and diastolic pressure, BMI and waist circumference, as well as in glycaemic values (p = 0.018).

Conclusions

A nutritional motivational intervention may be useful in improving dietary habits and health status of patients with T2D. We hope that a similar intervention will be applied in Campania and in other Italian regions.

Trial registration

Registration number is ISRCTN11067689; date of registration: 10/09/2018. Retrospectively registered.

Electronic supplementary material

The online version of this article (10.1186/s12889-018-6101-6) contains supplementary material, which is available to authorized users.

Food Preferences and Coping Strategies among Diabetic and Nondiabetic Households Served by US Food Pantries

Limited access to healthy food caused by food insecurity makes diabetes mellitus (DM) self-management more challenging. Using data from Hunger in America 2014 (n = 60,122 US food pantry users), we sought to understand food preferences and coping strategy utilization (e.g. choosing between paying for food and medical care) among households seeking assistance from US food pantries with and without DM members. The prevalence of wanting and not obtaining fruits, vegetables, dairy, and protein was high among all households. After adjusting for sociodemographic characteristics, households with DM members were more likely to want and not obtain fruits, vegetables, and dairy, and were also more likely to use several coping strategies to increase food access, compared to households without DM members. These results highlight the high demand for healthy food items among clients from US food pantries, particularly among households with DM, as well as the extra burden DM may place on food insecure households.

Effect of dark sweet cherry powder consumption on the gut microbiota, short-chain fatty acids, and biomarkers of gut health in obese db/db mice

Cherries are fruits containing fiber and bioactive compounds (e.g., polyphenolics) with the potential of helping patients with diabetes and weight disorders, a phenomenon likely related to changes in the complex host-microbiota milieu. The objective of this study was to investigate the effect of cherry supplementation on the gut bacterial composition, concentrations of caecal short-chain fatty acids (SCFAs) and biomarkers of gut health using an in vivo model of obesity. Obese diabetic (db/db) mice received a supplemented diet with 10% cherry powder (supplemented mice, n = 12) for 12 weeks; obese (n = 10) and lean (n = 10) mice served as controls and received a standard diet without cherry. High-throughput sequencing of the 16S rRNA gene and quantitative real-time PCR (qPCR) were used to analyze the gut microbiota; SCFAs and biomarkers of gut health were also measured using standard techniques. According to 16S sequencing, supplemented mice harbored a distinct colonic microbiota characterized by a higher abundance of mucin-degraders (i.e., Akkermansia) and fiber-degraders (the S24-7 family) as well as lower abundances of Lactobacillus and Enterobacteriaceae. Overall this particular cherry-associated colonic microbiota did not resemble the microbiota in obese or lean controls based on the analysis of weighted and unweighted UniFrac distance metrics. qPCR confirmed some of the results observed in sequencing, thus supporting the notion that cherry supplementation can change the colonic microbiota. Moreover, the SCFAs detected in supplemented mice (caproate, methyl butyrate, propionate, acetate and valerate) exceeded those concentrations detected in obese and lean controls except for butyrate. Despite the changes in microbial composition and SCFAs, most of the assessed biomarkers of inflammation, oxidative stress, and intestinal health in colon tissues and mucosal cells were similar in all obese mice with and without supplementation. This paper shows that dietary supplementation with cherry powder for 12 weeks affects the microbiota and the concentrations of SCFAs in the lower intestinal tract of obese db/db diabetic mice. These effects occurred in absence of differences in most biomarkers of inflammation and other parameters of gut health. Our study prompts more research into the potential clinical implications of cherry consumption as a dietary supplement in diabetic and obese human patients.

Nutraceutical approaches to metabolic syndrome

Metabolic Syndrome (MetS), affecting at least 30% of adults in the Western World, is characterized by three out of five variables, from high triglycerides, to elevated waist circumference and blood pressure. MetS is not characterized by elevated cholesterolemia, but is rather the consequence of a complex interaction of factors generally leading to increased insulin resistance. Drug treatments are of difficult handling, whereas well-characterized nutraceuticals may offer an effective alternative. Among these, functional foods, e.g. plant proteins, have been shown to improve insulin resistance and reduce triglyceride secretion. Pro- and pre-biotics, that are able to modify intestinal microbiome, reduce absorption of specific nutrients and improve the metabolic handling of energy-rich foods. Finally, specific nutraceuticals have proven to be of benefit, in particular, red-yeast rice, berberine, curcumin as well as vitamin D. All these can improve lipid handling by the liver as well as ameliorate insulin resistance. While lifestyle approaches, such as with the Mediterranean diet, may prove to be too complex for the single patient, better knowledge of selected nutraceuticals and more appropriate formulations leading to improved bioavailability will certainly widen the use of these agents, already in large use for the management of these very frequent patient groups. Key messages Functional foods, e.g. plant proteins, improve insulin resistance. Pro- and pre-biotics improve the metabolic handling of energy-rich foods. Nutraceutical can offer a significant help in handling MetS patients being part of lifestyle recommendations.

Effect of n-3 Polyunsaturated Fatty Acid Supplementation on Metabolic and Inflammatory Biomarkers in Type 2 Diabetes Mellitus Patients

BACKGROUND

Type 2 diabetes mellitus (T2DM) is accompanied by chronic low-grade inflammation, with an imbalance in the secretion of adipokines and, worsening insulin resistance. Supplementation with n-3 PUFA in T2DM decreases inflammatory markers, the purpose of the study was to investigate the effect of n-3 PUFA supplementation on adipokines, metabolic control, and lipid profile in T2DM Mexican adults.

METHODS

In a randomized, single-blind, placebo-controlled pilot study, 54 patients with T2DM received 520 mg of DHA + EPA-enriched fish-oil (FOG) or a placebo (PG) daily. Baseline and 24-week anthropometric and biochemical measurements included glucose, insulin, glycosylated hemoglobin (Hb1Ac), leptin, adiponectin, resistin, and lipid profile; n-3 PUFA intake was calculated in g/day.

RESULTS

Waist circumference and blood glucose showed significant reductions in the FOG group (p = 0.001 and p = 0.011, respectively). Hb1Ac (p = 0.009 and p = 0.004), leptin (p < 0.000 and p < 0.000), and leptin/adiponectin ratio (p < 0.000 and p < 0.000) decreased significantly in both groups after 24 weeks (FOG and PG respectively). Serum resistin (FOG p < 0.000 and PG p = 0.001), insulin (FOG p < 0.000 and PG p < 0.000), and HOMA-IR (FOG p = 0.000 and PG p < 0.000) increased significantly in both groups. FOG had an overall improvement in the lipid profile with a significant decrease in triacylgycerols (p = 0.002) and atherogenic index (p = 0.031); in contrast, the PG group had increased total cholesterol (p < 0.000), non-HDL cholesterol (p < 0.000), and atherogenic index (p = 0.017).

CONCLUSIONS

We found a beneficial effect of n-3 PUFA supplementation on waist circumference, glucose, Hb1Ac, leptin, leptin/adiponectin ratio, and lipid profile, without significant changes in adiponectin, and increases in resistin, insulin, and HOMA-IR in both groups.

Nutritional approaches for managing obesity-associated metabolic diseases

Obesity is an ongoing pandemic and serves as a causal factor of a wide spectrum of metabolic diseases including diabetes, fatty liver disease, and cardiovascular disease. Much evidence has demonstrated that nutrient overload/overnutrition initiates or exacerbates inflammatory responses in tissues/organs involved in the regulation of systemic metabolic homeostasis. This obesity-associated inflammation is usually at a low-grade and viewed as metabolic inflammation. When it exists continuously, inflammation inappropriately alters metabolic pathways and impairs insulin signaling cascades in peripheral tissues/organs such as adipose tissue, the liver and skeletal muscles, resulting in local fat deposition and insulin resistance and systemic metabolic dysregulation. In addition, inflammatory mediators, e.g., proinflammatory cytokines, and excessive nutrients, e.g., glucose and fatty acids, act together to aggravate local insulin resistance and form a vicious cycle to further disturb the local metabolic pathways and exacerbate systemic metabolic dysregulation. Owing to the critical role of nutrient metabolism in controlling the initiation and progression of inflammation and insulin resistance, nutritional approaches have been implicated as effective tools for managing obesity and obesity-associated metabolic diseases. Based on the mounting evidence generated from both basic and clinical research, nutritional approaches are commonly used for suppressing inflammation, improving insulin sensitivity, and/or decreasing fat deposition. Consequently, the combined effects are responsible for improvement of systemic insulin sensitivity and metabolic homeostasis.

Adipokines: Potential Therapeutic Targets for Vascular Dysfunction in Type II Diabetes Mellitus and Obesity

Adipokines are bioactive molecules that regulate several physiological functions such as energy balance, insulin sensitization, appetite regulation, inflammatory response, and vascular homeostasis. They include proinflammatory cytokines such as adipocyte fatty acid binding protein (A-FABP) and anti-inflammatory cytokines such as adiponectin, as well as vasodilator and vasoconstrictor molecules. In obesity and type II diabetes mellitus (DM), insulin resistance causes impairment of the endocrine function of the perivascular adipose tissue, an imbalance in the secretion of vasoconstrictor and vasodilator molecules, and an increased production of reactive oxygen species. Recent studies have shown that targeting plasma levels of adipokines or the expression of their receptors can increase insulin sensitivity, improve vascular function, and reduce the risk of cardiovascular morbidity and mortality. Several reviews have discussed the potential of adipokines as therapeutic targets for type II DM and obesity; however, this review is the first to focus on their therapeutic potential for vascular dysfunction in type II DM and obesity.