Impact of the metabolic syndrome on the evolution of neurodegenerative diseases

The Metabolic Syndrome, a Human Disease

This review focuses on the question of metabolic syndrome (MS) being a complex, but essentially monophyletic, galaxy of associated diseases/disorders, or just a syndrome of related but rather independent pathologies. The human nature of MS (its exceptionality in Nature and its close interdependence with human action and evolution) is presented and discussed. The text also describes the close interdependence of its components, with special emphasis on the description of their interrelations (including their syndromic development and recruitment), as well as their consequences upon energy handling and partition. The main theories on MS's origin and development are presented in relation to hepatic steatosis, type 2 diabetes, and obesity, but encompass most of the MS components described so far. The differential effects of sex and its biological consequences are considered under the light of human social needs and evolution, which are also directly related to MS epidemiology, severity, and relations with senescence. The triggering and maintenance factors of MS are discussed, with especial emphasis on inflammation, a complex process affecting different levels of organization and which is a critical element for MS development. Inflammation is also related to the operation of connective tissue (including the adipose organ) and the widely studied and acknowledged influence of diet. The role of diet composition, including the transcendence of the anaplerotic maintenance of the Krebs cycle from dietary amino acid supply (and its timing), is developed in the context of testosterone and β-estradiol control of the insulin-glycaemia hepatic core system of carbohydrate-triacylglycerol energy handling. The high probability of MS acting as a unique complex biological control system (essentially monophyletic) is presented, together with additional perspectives/considerations on the treatment of this 'very' human disease.

The Supplementation of Sechium edule var. nigrum spinosum (Chayote) Promotes Nrf2-Mediated Antioxidant Protection in Older Adults with Metabolic Syndrome

The aim was to determine the effect of Sechium edule var. nigrum spinosum (chayote) on gene expression related to antioxidant protection mechanisms and the inflammatory process in older adults with metabolic syndrome (MetS). A quasi-experimental study was carried out in a convenience sample of 46 older adults diagnosed with MetS: (i) placebo group (PG; n = 20); (ii) experimental group (EG; n = 26). The clinical, biochemical, anthropometric parameters and SOD, GPx, and CAT enzyme activity, alongside total oxidant status (TOS), total antioxidant status (TAS), oxidative stress index (OSI), cytokines (IL-6, IL-8 and TNF-α), and mRNA expression of SOD, GPx, CAT, IL-6, IL-8, TNF-α, Nrf2, NFkB p50, and NFkB p65, were measured at baseline and 6 months post-intervention. A statistically significant decrease was observed in TOS (baseline, 28.9 ± 3.6 vs. post, 23.7 ± 3.4, p < 0.01) and OSI (baseline, 24.1 ± 3.8 vs. post, 17.7 ± 4), as well as an increase in IL-6 (baseline, 10.7 ± 1.1 vs. post, 12.3 ± 2, p = 0.03), SOD activity (baseline, 167.1 ± 11.9 vs. post, 180.6 ± 7.6, p < 0.05), CAT activity (baseline, 1.0 ± 0.2 vs. post, 1.3 ± 0.2, p < 0.01), and TAS (baseline, 1.1 ± 0.1 vs. post, 1.4 ± 0.1, p < 0.01) in the EG compared to the PG. Regarding the expression of Nrf2, SOD, and IL-6, the EG showed a significant increase vs. basal levels (47%, 44%, and 43%, respectively). Our findings suggest that Sechium edule supplementation promotes the antioxidant response and decreases oxidative stress via Nrf2.

Retinal neurodegeneration in metabolic syndrome: a spectral optical coherence tomography study

AIM

To evaluate the effects of metabolic syndrome (MetS) on retinal neurodegeneration by optical coherence tomography (OCT).

METHODS

Patients diagnosed as MetS were compared with the age and sex-matched healthy control group (CG). Waist circumference measurements, fasting serological biochemical tests, and systemic blood pressures of all participants were evaluated. The MetS group was divided into 3 subgroups according to the number of MetS components: hypertension, diabetes mellitus, dyslipidemia (low-, high-density lipoprotein, hypertriglyceridemia), and visceral obesity findings; 3-component MetS3, 4-component MetS4, and all-component MetS5. All patients underwent complete eye examination and spectral OCT retinal imaging.

RESULTS

Totally 58 eyes of 58 patients were included in the MetS group and 63 eyes of 63 age and sex-matched healthy subjects were included in CG. MetS group was composed of 22 subjects in MetS3, 21 subjects in MetS4, and 15 subjects in the MetS5 subgroup. Mean foveal thickness (MetS, 218.7±23.1 µm vs CG, 228.8±21.9 µm, P=0.015), mean inferior (MetS, 283.4±17.0 µm vs CG, 288.7±38.4 µm, P=0.002), superior (MetS, 287.0±18.5 µm vs CG 297.3±17.1 µm, P=0.001), nasal (MetS 287.3±16.7 µm vs CG 297.9±13.9 µm, P=0.000) and temporal (274.5±17.6 µm vs CG 285.6±13.6 µm, P=0.000) thickness in the 3 mm Early Treatment of Diabetic Retinopathy Study (ETDRS) circle was significantly lower in the MetS group. There was no statistically significant difference in the mean inferior, superior, nasal, and temporal thickness of 6 mm ETDRS circle, total macular volume, peripapillary and macular retinal nerve fiber layer, macular ganglion cell layer with inner plexiform layer, and ganglion cell complex. No statistically significant difference was found in these values ​​between the MetS3, MetS4, and the MetS5 groups.

CONCLUSION

A significant reduction in central macular region thickness in MetS is detected and macular thickness is more susceptible to MetS induced neurodegeneration than peripapillary retinal nerve fiber layer.

The joint association of physical activity and sedentary behavior with metabolic syndrome among urban men aged 60+ years in regional China

Objectives

Metabolic syndrome (MetS) is a major public health issue worldwide, which is preventable through physical activity (PA) promotion and sedentary behavior (SB) reduction. However, the joint association of PA and SB with MetS was not well-investigated, particularly in elderly people. This study aimed to examine separate and joint associations of PA and SB with MetS among elderly urban men in China.

Methods

In this cross-sectional study conducted in mid-2018, participants were urban men aged 60+ years randomly selected from in Nanjing of China. Exposure variables were PA and SB. The outcome variable was MetS. A participant was categorized as "having MetS" or "not having MetS" in the analysis. Independent variables were PA and SB, which were categorized as "sufficient PA or insufficient PA" and "shortened SB or prolonged SB", respectively. Mixed-effects logistics regression models were applied to calculate odds ratios (ORs) and 95% confidence intervals (CIs) to assess the association of PA and SB with MetS.

Results

Totally, 5,520 from 5,792 eligible participants were randomly recruited and their mean age was 68.9 (standard deviation: 16.9) years. The prevalence of MetS was 30.8% (95%CI = 29.6%, 32.0%) among urban men aged 60+ years in the study. After adjustment for potential confounders, subjects with sufficient PA were less likely (OR = 0.77, 95%CI = 0.67, 0.88) to experience MetS, independently of SB, relative to their counterparts with insufficient PA, while a lower odds (OR = 0.74; 95%CI = 0.61, 0.89) of experiencing MetS was examined for participants with shortened SB, also independently of PA, compared to those with prolonged SB in the study. Furthermore, compared to participants with insufficient PA and prolonged SB, those either within categories of insufficient PA and shortened SB (OR = 0.81; 95%CI = 0.65, 0.99), sufficient PA and prolonged SB (OR = 0.80; 95%CI = 0.70, 0.92), or sufficient PA and shortened SB (OR = 0.41; 95%CI = 0.26, 0.63) were at significantly lower risk to experience MetS, respectively.

Conclusions

PA was negatively associated with MetS, and SB was positively linked to MetS, which were independent of each other. Moreover, sufficient PA and shortened SB might exert additively joint influence on MetS. This study has important implications that concurrent PA promotion and SB reduction shall be encouraged for people to optimize the effectiveness of MetS prevention.

Effect of Walking Steps Measured by a Wearable Activity Tracker on Improving Components of Metabolic Syndrome: A Prospective Study

We compared the improvement in components of metabolic syndrome (MS) before and after lifestyle modification, as determined by daily step counts (on a wrist-worn Fitbit®) in participants with and without MS recruited from volunteers attending medical health checkup programs. A linear mixed model was used to analyze the change in MS components between participants with and without MS by group × time interaction. Multiple logistic regression analysis after adjustment for confounders was used to obtain odds ratios (ORs) and 95% confidence intervals (CIs) for improvements in MS components per 1000-steps/day increments. Waist circumference, triglycerides, fasting plasma glucose, and diastolic blood pressure were significantly different between participants with and without MS (group × time: p = 0.010, p < 0.001, p = 0.025, and p = 0.010, respectively). Multivariable-adjusted ORs (95% CI) of improvement in MS components per 1000-steps/day increments were 1.24 (1.01−1.53) in participants with and 1.14 (0.93−1.40) in participants without MS. Walking improved MS components more in individuals with than without MS. From a public health perspective, walking should be encouraged for high-risk MS individuals.

“Big Data” Approaches for Prevention of the Metabolic Syndrome

Metabolic syndrome (MetS) is characterized by the concurrence of multiple metabolic disorders resulting in the increased risk of a variety of diseases related to disrupted metabolism homeostasis. The prevalence of MetS has reached a pandemic level worldwide. In recent years, extensive amount of data have been generated throughout the research targeted or related to the condition with techniques including high-throughput screening and artificial intelligence, and with these “big data”, the prevention of MetS could be pushed to an earlier stage with different data source, data mining tools and analytic tools at different levels. In this review we briefly summarize the recent advances in the study of “big data” applications in the three-level disease prevention for MetS, and illustrate how these technologies could contribute tobetter preventive strategies.

Physical activity and/or sedentary behaviour and the development of functional disability in community-dwelling older adults in Tsuru, Japan: a prospective cohort study (the Tsuru Longitudinal Study)

OBJECTIVES

To clarify the association between moderate-to-vigorous physical activity (MVPA) and/or sedentary behaviour (SB) and the incidence of functional disability (FD) in older adults.

DESIGN

Prospective cohort study.

SETTING

Local municipality of Tsuru, Yamanashi, Japan. We conducted a baseline survey in January 2016. Follow-up was commenced on 1 February 2016 and completed on 31 October 2018.

PARTICIPANTS

All individuals (6661 people) aged >65 years who were independently living in the community were eligible.

METHODS AND OUTCOME MEASURES

MVPA (min/week) and SB (min/day) were measured using self-administered questionnaires in 5311 independently living older adults who participated in this study. The follow-up period was 33 months, and the incidence of FD was objectively determined by experts. The participants were divided into three groups based on MVPA distribution (non-MVPA, 0 min; short-MVPA, 1-299 min and long-MVPA, ≥300 min/week) and into two groups based on the median value of SB (short-SB,<190 min; and long-SB, ≥190 min/day). The participants were also classified into six categories based on different combinations of MVPA and SB. Cox proportional hazards model was used to calculate the HR and 95% CI for FD development with MVPA, SB and a combination of these behaviours.

RESULTS

Among the included participants, 2415 were male and 2896 were female. The mean ages (SD) of the male and female participants were 74.5 (6.8) and 74.9 (6.9) years, respectively. The total number of participants with chronic conditions was 3489 (65.7%). Using the non-MVPA group as the reference, the multivariable-adjusted HR (95% CI) was 0.68 (0.54 to 0.84) in the short-MVPA group and 0.53 (0.41 to 0.69) in the long-MVPA group. Regarding SB, the short-SB group had an HR of 0.86 (0.71 to 1.03) compared with the long-SB group. The combined behaviour showed the lowest HR in the long-MVPA and short-SB group 0.49 (0.34 to 0.72) and the long-MVPA and long-SB group 0.49 (0.34 to 0.68), respectively.

CONCLUSIONS

Long-MVPA had a robust association with FD development, whereas short-SB had a modest association. Moreover, a combination of these behaviours had a stronger association than individual behaviours. If the identified associations are assumed to be causal in nature, these findings suggest that encouraging older adults to engage in MVPA and reduce SB in their daily lives could be effective to prevent or delay FD development.

Delving into the Nutraceutical Benefits of Purple Carrot against Metabolic Syndrome and Cancer: A Review

Metabolic syndrome (MetS) constitutes a group of risk factors that may increase the risk of cancer and other health problems. Nowadays, researchers are focusing on food compounds that could prevent many chronic diseases. Thus, people are shifting from dietary supplements towards healthy nutritional approaches. As a nutritious and natural food source, purple carrot (Daucus carota spp. Sativus var. atrorubens Alef.) roots could have an important role in the prevention of MetS as well as cancer. This review provides deep insight into the role of purple carrot’s main bioactive compounds and their effectiveness against MetS and cancer. Phenolic compounds, such as anthocyanin, present in purple carrot roots may be especially productive in avoiding or delaying the onset of cardiovascular disease (CVDs), obesity, diabetes, and cancer. Anthocyanins and other phenolics are successful in reducing metabolic changes and inflammation by inhibiting inflammatory effects. Many researchers have made efforts to employ this vegetable in the prevention and treatment of MetS and cancer. However, more advanced studies are required for the identification of its detailed role, effectiveness, suitable intake, and the effect of its bioactive compounds against these diseases.

Targeting hypercoagulation to alleviate Alzheimer's disease progression in metabolic syndrome

INTRODUCTION

Metabolic Syndrome (MetS) constitutes an important risk factor for Alzheimer's disease (AD); however, the mechanism linking these two disorders has not been completely elucidated. Hence, hypercoagulation may account for the missing hallmark connecting MetS and AD. The present review proposes how hemostatic imbalance triggered in MetS advances in the context of AD. MetS causes interruption of insulin signaling and inflammation, inciting insulin resistance in the brain. Subsequently, neuroinflammation and brain endothelial dysfunction are prompted that further intensify the exorbitant infiltration of circulating lipids and platelet aggregation, thereby causing hypercoagulable state, impairing fibrinolysis and eventually inducing prothrombic state in the brain leading to neurodegeneration.

OBJECTIVE

This study aims to understand the role of hypercoagulation in triggering the progression of neurodegeneration in MetS. It also offers a few interventions to prevent the progression of AD in MetS targeting hypercoagulation.

METHODS

Literature studies based on MetS related neurodegeneration, the impact of coagulation on aggravating obesity and AD via the mechanisms of BBB disruption, neuroinflammation, and hypofibrinolysis.

CONCLUSION

The present paper proposes the hypothesis that hypercoagulation might amplify MetS associated insulin resistance, neuroinflammation, BBB disruption, and amyloid beta accumulation which eventually leads to AD.

Resveratrol Supplementation Attenuates Cognitive and Molecular Alterations under Maternal High-Fat Diet Intake: Epigenetic Inheritance over Generations

Environmental factors such as maternal high-fat diet (HFD) intake can increase the risk of age-related cognitive decline in adult offspring. Epigenetic mechanisms are a possible link between diet effect and neurodegeneration across generations. Here, we found a significant decrease in triglyceride levels in a high-fat diet with resveratrol (RSV) HFD + RSV group and the offspring. Firstly, we obtained better cognitive performance in HFD+RSV groups and their offspring. Molecularly, a significant increase in DNA methylation (5-mC) levels, as well as increased gene expression of DNA methyltransferase 1 (Dnmt1) and Dnmt3a in HFD + RSV F1 group, were found. Furthermore, a significant increase of N6-Methyladenosine methylation (m6A) levels in HFD+RSV F1, as well as changes in gene expression of its enzymes Methyltransferase like 3 (Mettl3) and FTO alpha-ketoglutarate dependent dioxygenase (Fto) were found. Moreover, we found a decrease in gene expression levels of pro-inflammatory markers such as Interleukin 1β (Il1-β), Interleukin 6 (Il-6), Tumor necrosis factor-α (Tnf-α), C-X-C motif chemokine ligand 10 (Cxcl-10), the pro-inflammatory factors monocyte chemoattractant protein 1 (Mcp-1) and Tumor growth factor-β1 (Tgf-β1) in HFD+RSV and HFD+RSV F1 groups. Moreover, there was increased gene expression of neurotrophins such as Neural growth factor (Ngf), Neurotrophin-3 (Nt3), and its receptors Tropomyosin receptor kinase TrkA and TrkB. Likewise, an increase in protein levels of brain-derived neurotrophic factor (BDNF) and phospho-protein kinase B (p-Akt) in HFD+RSV F1 was found. These results suggest that maternal RSV supplementation under HFD intake prevents cognitive decline in senescence-accelerated mice prone 8 (SAMP8) adult offspring, promoting a reduction in triglycerides and leptin plasma levels, changes in the pro-inflammatory profile, and restoring the epigenetic landscape as well as synaptic plasticity.