Dietary Strategies Implicated in the Prevention and Treatment of Metabolic Syndrome

Metabolic Flexibility as an Adaptation to Energy Resources and Requirements in Health and Disease

The ability to efficiently adapt metabolism by substrate sensing, trafficking, storage, and utilization, dependent on availability and requirement, is known as metabolic flexibility. In this review, we discuss the breadth and depth of metabolic flexibility and its impact on health and disease. Metabolic flexibility is essential to maintain energy homeostasis in times of either caloric excess or caloric restriction, and in times of either low or high energy demand, such as during exercise. The liver, adipose tissue, and muscle govern systemic metabolic flexibility and manage nutrient sensing, uptake, transport, storage, and expenditure by communication via endocrine cues. At a molecular level, metabolic flexibility relies on the configuration of metabolic pathways, which are regulated by key metabolic enzymes and transcription factors, many of which interact closely with the mitochondria. Disrupted metabolic flexibility, or metabolic inflexibility, however, is associated with many pathological conditions including metabolic syndrome, type 2 diabetes mellitus, and cancer. Multiple factors such as dietary composition and feeding frequency, exercise training, and use of pharmacological compounds, influence metabolic flexibility and will be discussed here. Last, we outline important advances in metabolic flexibility research and discuss medical horizons and translational aspects.

Dietary patterns and physical activity in the metabolically (un)healthy obese: the Dutch Lifelines cohort study

BACKGROUND

Diversity in the reported prevalence of metabolically healthy obesity (MHO), suggests that modifiable factors may be at play. We evaluated differences in dietary patterns and physical activity between MHO and metabolically unhealthy obesity (MUO).

METHODS

Cross-sectional data of 9270 obese individuals (30-69 years) of the Lifelines Cohort Study was used. MHO was defined as obesity and no metabolic syndrome risk factors and no cardiovascular disease history. MUO was defined as obesity and ≥2 metabolic syndrome risk factors. Sex-specific associations of dietary patterns (identified by principal component analysis) and physical activity with MHO were assessed by multivariable logistic regression (reference group: MUO). Analyses were adjusted for multiple covariates.

RESULTS

Among 3442 men and 5828 women, 10.2% and 24.4% had MHO and 56.9% and 35.3% MUO, respectively. We generated four obesity-specific dietary patterns. Two were related to MHO, and in women only. In the highest quartile (Q) of 'bread, potatoes and sweet snacks' pattern, odds ratio (OR) (95% CI) for MHO was 0.52 (0.39-0.70). For the healthier pattern 'fruit, vegetables and fish', an OR of 1.36 (1.09-1.71) in Q3 and 1.55 (1.21-1.97) in Q4 was found for MHO. For physical activity, there was a positive association between moderate physical activity and vigorous physical activity in the highest tertile and MHO in women and men, respectively (OR 1.19 (1.01-1.41) and OR 2.02 (1.50-2.71)).

CONCLUSION

The healthier diet -characterized by 'fruit, vegetables and fish'- and moderate physical activity in women, and vigorous physical activity in men may be related to MHO. The (refined) carbohydrate-rich 'bread, potatoes and sweet snacks' dietary pattern was found to counteract MHO in women.

New insights into ANGPLT3 in controlling lipoprotein metabolism and risk of cardiovascular diseases

Dyslipidemia, characterized by elevation of plasma low density lipoprotein cholesterol (LDL-C), triglyceride (TG) and reduction of plasma high density lipoprotein cholesterol (HDL-C), has been verified as a causal risk factor for cardiovascular diseases (CVD), leading to a high mortality rate in general population. It is important to understand the molecular metabolism underlying dyslipidemia in order to reduce the risk and to develop effective therapeutic approaches against CVD. ANGPTL3 (human) or Angptl3 (mouse), one member of the angiopoietin-like protein (ANGPTL) family, has been identified as an important regulator of lipid metabolism by inhibiting LPL and EL activity. Results have demonstrated that inactivation of Angptl3 in mice could obviously reduce the level of TG, LDL-C and the atherosclerotic lesion size, leading to a lower risk for dyslipidemia and CVD. Additionally, in humans, carriers with homozygous LOF mutations in ANGPTL3 have lower plasma LDL-C, TG levels and lower risk of atherosclerosis compared to the non-carriers. Here, we collect the latest data and results, giving a new insight into the important role of ANGPTL3 in controlling lipoprotein metabolism. Finally, we introduce two update reports on the antisense oligonucleotide and monoclonal antibody-based inactivation of ANGPTL3 in human clinical trials, to identify that ANGPTL3 could be a novel and effective target for the treatment of dyslipidemia and CVD.

Improvement of glucose and lipid metabolism via mung bean protein consumption: clinical trials of GLUCODIA™ isolated mung bean protein in the USA and Canada

The aim of the present study was to confirm the effects of a commercially available mung bean protein isolate (GLUCODIA™) on glucose and lipid metabolism. The main component of GLUCODIA™ is 8S globulin, which constitutes 80 % of the total protein. The overall structure of this protein closely resembles soyabean β-conglycinin, which accounts for 20 % of total soya protein (soya protein isolate; SPI). Many physiological beneficial effects of β-conglycinin have been reported. GLUCODIA™ is expected to produce beneficial effects with fewer intakes than SPI. We conducted two independent double-blind, placebo-controlled clinical studies. In the first (preliminary dose decision trial) study, mung bean protein was shown to exert physiological beneficial effects when 3·0 g were ingested per d. In the second (main clinical trial) study, mung bean protein isolate did not lower plasma glucose levels, although the mean insulin level decreased with consumption of mung bean protein. The homeostatic model assessment of insulin resistance (HOMA-IR) values significantly decreased with mung bean protein. The mean TAG level significantly decreased with consumption of mung bean protein isolate. A significant increase in serum adiponectin levels and improvement in liver function enzymes were observed. These findings suggest that GLUCODIA™ could be useful in the prevention of insulin resistance and visceral fat accumulation, which are known to trigger the metabolic syndrome, and in the prevention of liver function decline.

Expression enhancement in brown adipose tissue of genes related to thermogenesis and mitochondrial dynamics after administration of pepsin egg white hydrolysate

Pepsin egg white hydrolysate enhanced mitochondria proliferation on brown adipose tissue and thermogenesis. Reduced body weight and adiposity were observed.

The Efficacy of Acupuncture on Anthropometric Measures and the Biochemical Markers for Metabolic Syndrome: A Randomized Controlled Pilot Study

Background

Many previous studies have shown the potential therapeutic effect of acupuncture for metabolic syndrome (MetS). However, most of these studies were limited by short durations of observation and a lack of sham acupuncture as control. We designed a randomized controlled trial, used sham acupuncture as the control, and evaluated the efficacy over 12 weeks of treatment and 12 weeks of follow-up.

Methods/Design

The study was designed as a multicentre, parallel-group, randomized, double-blinded trial. 40 patients were randomly assigned to two groups: treatment group (treated with acupuncture) and control group (treated with sham acupuncture). Outcomes were measured at 4, 8, and 12 weeks and 3 months after treatment.

Results

33 participants (17 in acupuncture group and 16 in control group) completed the treatment and the follow-up. Decreases from baseline in mean waist circumference (WC) and weight at the end of treatment were 4.85 cm (95% CI [2.405,5.595]) and 4.00 kg (95% CI [1.6208,4.4498]) in acupuncture group and 1.62 cm and 1.64 kg in control group (P < 0.01). The changes in mean glycosylated haemoglobin (HbA1c), triglycerides (TG), total cholesterol (TC), and blood pressure in acupuncture group were greater than the changes in control group (P < 0.05, P < 0.01).

Conclusion

Acupuncture decreases WC, HC, HbA1c, TG, and TC values and blood pressure in MetS.

Association of low dietary folate intake with lower CAMKK2 gene methylation, adiposity, and insulin resistance in obese subjects

Folate deficiency has been putatively implicated in the onset of diverse metabolic abnormalities, including insulin resistance, by altering epigenetic processes on key regulatory genes. The calcium/calmodulin-dependent protein kinase kinase 2 (CAMKK2) is involved in the regulation of critical metabolic processes such as adiposity and glucose homeostasis. This study hypothesized associations between low folate intakes and lower methylation levels of the CAMKK2 gene, with the presence of metabolic alterations in subjects with obesity. A cross-sectional ancillary study was conducted in obese subjects (n=47) from the RESMENA study (Spain). Fat mass was measured by dual-energy x-ray absorptiometry. Dietary intake and metabolic profile were assessed by validated methods. DNA methylation and gene expression in peripheral white blood cells were analyzed by microarray approaches. A total of 51 cytosine-phosphate-guanine sites were associated with folate intake (false discovery rate values < 0.0001), including one located in the 5' untranslated region of the CAMKK2 gene (Illumina ID, cg16942632), which was selected and separately analyzed. Subjects with total folate intake lower than 300μg/d showed more fat mass (especially trunk fat), as well as statistically higher levels of glucose, insulin, homeostatic model assessment-insulin resistance (HOMA-IR) index, cortisol, and plasminogen activator inhibitor-1 than those consuming at least or more than 300μg/d. Of note, folate deficiency was related to lower CAMKK2 methylation. Interestingly, CAMKK2 methylation negatively correlated with the HOMA-IR index. Furthermore, CAMKK2 expression directly correlated with HOMA-IR values. In summary, this study suggests associations between low folate intakes, lower CAMKK2 gene methylation, and insulin resistance in obese individuals.

Melatonin, mitochondria, and the metabolic syndrome

A number of risk factors for cardiovascular disease including hyperinsulinemia, glucose intolerance, dyslipidemia, obesity, and elevated blood pressure are collectively known as metabolic syndrome (MS). Since mitochondrial activity is modulated by the availability of energy in cells, the disruption of key regulators of metabolism in MS not only affects the activity of mitochondria but also their dynamics and turnover. Therefore, a link of MS with mitochondrial dysfunction has been suspected since long. As a chronobiotic/cytoprotective agent, melatonin has a special place in prevention and treatment of MS. Melatonin levels are reduced in diseases associated with insulin resistance like MS. Melatonin improves sleep efficiency and has antioxidant and anti-inflammatory properties, partly for its role as a metabolic regulator and mitochondrial protector. We discuss in the present review the several cytoprotective melatonin actions that attenuate inflammatory responses in MS. The clinical data that support the potential therapeutical value of melatonin in human MS are reviewed.

Psoriasis and Cardiovascular Comorbidities: Focusing on Severe Vascular Events, Cardiovascular Risk Factors and Implications for Treatment

Psoriasis is a common and chronic inflammatory disease of the skin. It may impair the physical and psychosocial function of patients and lead to decreased quality of life. Traditionally, psoriasis has been regarded as a disease affecting only the skin and joints. More recently, studies have shown that psoriasis is a systemic inflammatory disorder which can be associated with various comorbidities. In particular, psoriasis is associated with an increased risk of developing severe vascular events such as myocardial infarction and stroke. In addition, the prevalence rates of cardiovascular risk factors are increased, including hypertension, diabetes mellitus, dyslipidemia, obesity, and metabolic syndrome. Consequently, mortality rates have been found to be increased and life expectancy decreased in patients with psoriasis, as compared to the general population. Various studies have also shown that systemic treatments for psoriasis, including methotrexate and tumor necrosis factor-α inhibitors, may significantly decrease cardiovascular risk. Mechanistically, the presence of common inflammatory pathways, secretion of adipokines, insulin resistance, angiogenesis, oxidative stress, microparticles, and hypercoagulability may explain the association between psoriasis and cardiometabolic disorders. In this article, we review the evidence regarding the association between psoriasis and cardiovascular comorbidities, focusing on severe vascular events, cardiovascular risk factors and implications for treatment.

Comparison of the Effects of Goat Dairy and Cow Dairy Based Breakfasts on Satiety, Appetite Hormones, and Metabolic Profile

The satiating effects of cow dairy have been thoroughly investigated; however, the effects of goat dairy on appetite have not been reported so far. Our study investigates the satiating effect of two breakfasts based on goat or cow dairy and their association with appetite related hormones and metabolic profile. Healthy adults consumed two breakfasts based on goat (G-Breakfast) or cow (C-Breakfast) dairy products. Blood samples were taken and VAS tests were performed at different time points. Blood metabolites were measured and Combined Satiety Index (CSI) and areas under the curves (AUC) were calculated. Desire to eat rating was significantly lower (breakfast &amp; time interaction p < 0.01) and hunger rating tended to be lower (breakfast &amp; time interaction p = 0.06) after the G-breakfast. None of the blood parameters studied were different between breakfasts; however, AUC_GLP-1 was inversely associated with the AUC_hunger and AUC_{desire-to-eat} after the G-Breakfast, whereas triglyceride levels were directly associated with AUC_CSI after the C-Breakfast. Our results suggest a slightly higher satiating effect of goat dairy when compared to cow dairy products, and pointed to a potential association of GLP-1 and triglyceride levels with the mechanisms by which dairy products might affect satiety after the G-Breakfast and C-Breakfast, respectively.

Obesity

Excessive fat deposition in obesity has a multifactorial aetiology, but is widely considered the result of disequilibrium between energy intake and expenditure. Despite specific public health policies and individual treatment efforts to combat the obesity epidemic, >2 billion people worldwide are overweight or obese. The central nervous system circuitry, fuel turnover and metabolism as well as adipose tissue homeostasis are important to comprehend excessive weight gain and associated comorbidities. Obesity has a profound impact on quality of life, even in seemingly healthy individuals. Diet, physical activity or exercise and lifestyle changes are the cornerstones of obesity treatment, but medical treatment and bariatric surgery are becoming important. Family history, food environment, cultural preferences, adverse reactions to food, perinatal nutrition, previous or current diseases and physical activity patterns are relevant aspects for the health care professional to consider when treating the individual with obesity. Clinicians and other health care professionals are often ill-equipped to address the important environmental and socioeconomic drivers of the current obesity epidemic. Finally, understanding the epigenetic and genetic factors as well as metabolic pathways that take advantage of 'omics' technologies could play a very relevant part in combating obesity within a precision approach.

Effects of Natural Products on Fructose-Induced Nonalcoholic Fatty Liver Disease (NAFLD)

As a sugar additive, fructose is widely used in processed foods and beverages. Excessive fructose consumption can cause hepatic steatosis and dyslipidemia, leading to the development of metabolic syndrome. Recent research revealed that fructose-induced nonalcoholic fatty liver disease (NAFLD) is related to several pathological processes, including: (1) augmenting lipogenesis; (2) leading to mitochondrial dysfunction; (3) stimulating the activation of inflammatory pathways; and (4) causing insulin resistance. Cellular signaling research indicated that partial factors play significant roles in fructose-induced NAFLD, involving liver X receptor (LXR)α, sterol regulatory element binding protein (SREBP)-1/1c, acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS), stearoyl-CoA desaturase (SCD), peroxisome proliferator–activated receptor α (PPARα), leptin nuclear factor-erythroid 2-related factor 2 (Nrf2), nuclear factor kappa B (NF-κB), tumor necrosis factor α (TNF-α), c-Jun amino terminal kinase (JNK), phosphatidylinositol 3-kinase (PI3K) and adenosine 5′-monophosphate (AMP)-activated protein kinase (AMPK). Until now, a series of natural products have been reported as regulators of NAFLD in vivo and in vitro. This paper reviews the natural products (e.g., curcumin, resveratrol, and (−)-epicatechin) and their mechanisms of ameliorating fructose-induced NAFLD over the past years. Although, as lead compounds, natural products usually have fewer activities compared with synthesized compounds, it will shed light on studies aiming to discover new drugs for NAFLD.