Intermittent fasting and 'metabolic switch': Effects on metabolic syndrome, prediabetes and type 2 diabetes

Energy metabolism in health and diseases

Energy metabolism is indispensable for sustaining physiological functions in living organisms and assumes a pivotal role across physiological and pathological conditions. This review provides an extensive overview of advancements in energy metabolism research, elucidating critical pathways such as glycolysis, oxidative phosphorylation, fatty acid metabolism, and amino acid metabolism, along with their intricate regulatory mechanisms. The homeostatic balance of these processes is crucial; however, in pathological states such as neurodegenerative diseases, autoimmune disorders, and cancer, extensive metabolic reprogramming occurs, resulting in impaired glucose metabolism and mitochondrial dysfunction, which accelerate disease progression. Recent investigations into key regulatory pathways, including mechanistic target of rapamycin, sirtuins, and adenosine monophosphate-activated protein kinase, have considerably deepened our understanding of metabolic dysregulation and opened new avenues for therapeutic innovation. Emerging technologies, such as fluorescent probes, nano-biomaterials, and metabolomic analyses, promise substantial improvements in diagnostic precision. This review critically examines recent advancements and ongoing challenges in metabolism research, emphasizing its potential for precision diagnostics and personalized therapeutic interventions. Future studies should prioritize unraveling the regulatory mechanisms of energy metabolism and the dynamics of intercellular energy interactions. Integrating cutting-edge gene-editing technologies and multi-omics approaches, the development of multi-target pharmaceuticals in synergy with existing therapies such as immunotherapy and dietary interventions could enhance therapeutic efficacy. Personalized metabolic analysis is indispensable for crafting tailored treatment protocols, ultimately providing more accurate medical solutions for patients. This review aims to deepen the understanding and improve the application of energy metabolism to drive innovative diagnostic and therapeutic strategies.

Inpatient Dietary Behaviour Score (IDBS) Predicts the Risk of Hypoglycemia in Type 2 Diabetes Mellitus (T2DM) Patients

AIMS

The aim of this study was to develop the inpatient dietary behaviour score (IDBS) and validate its predictive performance in assessing the risk of hypoglycemia in patients with type 2 diabetes mellitus (T2DM).

METHODS

The study included patients with T2DM admitted to the Endocrinology Department of the First Affiliated Hospital of Chongqing Medical University between 1 March 2021 and 1 March 2023. Patients were categorised into hypoglycemia and non-hypoglycemia groups using a paired approach, with hypoglycemia defined as any point-of-care glucose test results ≤ 3.9 mmol/L. Clinical data were collected, and the IDBS was calculated using a self-designed scale with 11 variables. Subsequently, measures for predicting hypoglycemia risk in hospitalised T2DM patients were formulated.

RESULTS

A total of 1478 patients were included in the survey, with 739 patients in each of the hypoglycemic and non-hypoglycemic groups after pairing. Baseline differences were observed in education, marital status, job status, DM duration, glycosylated haemoglobin A1c (HbA1c), body mass index (BMI), hypoglycemia history, diabetic peripheral artery disease (DM-PAD), diabetic foot (DF), diabetic kidney disease (DKD), and diabetic retinopathy (DR) between the hypoglycemic and non-hypoglycemic groups. Significant correlations were found between the updated and baseline changes in the IDBS. The predictive efficacy was highest in DKD patients (OR = 1.82, 95% CI: 1.69-1.97, P = 6.75E-53). In multivariate analyses, only BMI, DM duration, diabetic foot and marriage response were included in the regression model. The area under the curve (AUC) and mean squared error (MSE) of the IDBS were 0.77 and 0.00039, respectively. A linear relationship existed between the IDBS and OR values, indicating that the risk of hypoglycemia increased with higher scores.

CONCLUSIONS

IDBS demonstrated a robust predictive effect on hypoglycemia. The variable data were easily obtainable, and the evaluation and calculation methods were straightforward. This scoring system could serve as a valuable reference for hypoglycemia prevention and screening of hospitalised diabetic patients at high risk of hypoglycemia.

The Effect of the 14:10-Hour Time-Restricted Feeding (TRF) Regimen on Selected Markers of Glucose Homeostasis in Diet-Induced Prediabetic Male Sprague Dawley Rats

BACKGROUND

Prediabetes is a condition that often precedes the onset of type 2 diabetes mellitus (T2DM). Literature evidence indicates that prediabetes is reversible, making it an important therapeutic target for preventing the progression to T2DM. Several studies have investigated intermittent fasting as a possible method to manage or treat prediabetes.

OBJECTIVES

This study evaluated the impact of a 14:10-hour time-restricted feeding (TRF) regimen on leptin concentration, insulin sensitivity and selected markers associated with the insulin signalling pathway and glucose homeostasis in diet-induced prediabetic rats.

METHODS

Twenty-four male Sprague Dawley rats were obtained and randomly divided into two dietary groups: group 1 (n = 6) received a standard diet and water, while group 2 (n = 18) was provided a high-fat, high-carbohydrate (HFHC) diet supplemented with 15% fructose for a period of 20 weeks to induce prediabetes. After confirming prediabetes, an intermittent fasting (IF) regimen was assigned to the rats while also having untreated and metformin-treated prediabetic rats serving as controls.

RESULTS

Both IF and HFHC-Met groups yield significantly lower blood glucose, leptin and BMI results compared to the prediabetic group. The IF group yielded significantly lower insulin, HOMA-IR and HbA1C than both controls.

CONCLUSIONS

The study showed the potential of IF in alleviating prediabetes-induced dysregulation of glucose homeostasis and therefore warrants further investigations into its use in the management of prediabetes.

Association between prediabetes and the incidence of gastric cancer: A meta-analysis

BACKGROUND

Prediabetes has been found to be associated with an elevated overall risk of cancer, which may be site-specific. we performed a protocol for systematic review and meta-analysis to investigate the correlation between prediabetes and the incidence of gastric cancer (GC).

METHODS

A thorough review of the literature was conducted in the PubMed, Embase, and Web of Science databases to identify pertinent observational studies with longitudinal follow-up. The random-effects model was employed to consolidate the data, taking into account the potential impact of heterogeneity.

RESULTS

A total of 13 datasets from 8 prospective cohort studies were included. The prevalence of prediabetes was 9.6%. During the mean follow-up duration of 7.1 to 12.2 years, 33,135 patients were diagnosed with GC. According to the results of the pooled analysis, prediabetes was associated with a mildly higher incidence of GC over time (risk ratio: 1.07, 95% confidence interval: 1.01-1.13, P = .03; I2 = 44%). Subsequent subgroup analyses indicated that the relationship between prediabetes and the heightened risk of GC may not be substantially influenced by factors such as the country in which the study was conducted, the average age of participants, their gender, the definition of prediabetes used, the prevalence of prediabetes at the beginning of the study, the incidence of GC within the studied population, or the adjustment made for body mass index (P for subgroup difference all >.05).

CONCLUSION

The presence of prediabetes may increase the risk of GC by a mild amount when compared with people with normoglycemia in community-derived adult populations.

Therapeutic Potential of Various Intermittent Fasting Regimens in Alleviating Type 2 Diabetes Mellitus and Prediabetes: A Narrative Review

Intermittent fasting has drawn significant interest in the clinical research community due to its potential to address metabolic complications such as obesity and type 2 diabetes mellitus. Various intermittent fasting regimens include alternate-day fasting (24 h of fasting followed by 24 h of eating), time-restricted fasting (fasting for 14 h and eating within a 10 h window), and the 5:2 diet (fasting for two days and eating normally for the other five days). Intermittent fasting is associated with a reduced risk of type 2 diabetes mellitus-related complications and can slow their progression. The increasing global prevalence of type 2 diabetes mellitus highlights the importance of early management. Since prediabetes is a precursor to type 2 diabetes mellitus, understanding its progression is essential. However, the long-term effects of intermittent fasting on prediabetes are not yet well understood. Therefore, this review aims to comprehensively compile existing knowledge on the therapeutic effects of intermittent fasting in managing type 2 diabetes mellitus and prediabetes.

Sex-specific effects of intermittent fasting on hippocampal neurogenesis via the gut-brain axis

Intermittent fasting (IF) is a widely used dietary strategy that has shown several advantageous impacts on general health and aging. IF has recently been linked to the control of neurogenesis, a crucial process for emotional control, memory, and learning, in the hippocampus. Nevertheless, there is little knowledge about the sex-specific impacts of IF on hippocampal neurogenesis and the related mechanisms, which were investigated in this study among both male and female rats, together with analyzing the involvement of the flora-gut-brain axis in facilitating these effects. Our findings show that IF favorably affects hippocampus neurogenesis in female mice relative to male mice, suggesting a sex-specific mechanism. In addition, IF influenced the diversity of the gut microbiota and decreased the synthesis of fructose-1-phosphate (F-1-P), which is believed together with fructose metabolism to be linked to neurological damage and cognitive decline. Collectively, these data indicate that the connection between the flora-gut-brain axis and hippocampus neurogenesis is significant.

Intermittent Fasting: Myths, Fakes and Truth on This Dietary Regimen Approach

Intermittent fasting (IF) has been indicated as a valuable alternative to the classical caloric restriction dietary regimen for lowering body weight and preventing obesity-related complications, such as metabolic syndrome and type II diabetes. However, is it effective? In this review article, we analyzed over 50 clinical studies in which IF, conducted by alternate day fasting (ADF) or time-restricted feeding (TRF), was compared with the caloric restriction approach. We evaluated the different roles of IF in treating and preventing human disorders such as metabolic syndrome, type II diabetes, and some types of cancer, as well as the usefulness of IF in reducing body weight and cardiovascular risk factors such as hypertension. Furthermore, we explored the cellular pathways targeted by IF to exert their beneficial effects by activating effector proteins that modulate cell functions and resistance to oxidative stress. In contrast, we investigated concerns regarding human health related to the adoption of IF dietary regimens, highlighting the profound debate surrounding weight loss regimens. We examined and compared several clinical trials to formulate an updated concept regarding IF and its therapeutic potential.

N-of-1 health optimization: Digital monitoring of biomarker dynamics to gamify adherence to metabolic switching

The digital health field is experiencing substantial growth due to its potential for sustained and longitudinal deployment. In turn, this may drive improved monitoring and intervention as catalysts for behavioral change compared to traditional point-of-care practices. In particular, the increase in incidence of population health challenges such as diabetes, heart disease, fatty liver disease, and other disorders coupled with rising healthcare costs have emphasized the importance of exploring technical, economics, and implementation considerations, among others in the decentralization of health and healthcare innovations. Both healthy individuals and patients stand to benefit from continued technical advances and studies in these domains. To address these points, this study reports a N-of-1 study comprised of sustained regimens of intermittent fasting, fitness (strength and cardiovascular training), and high protein, low carbohydrate diet and parallel monitoring. These regimens were paired with serial blood ketone, blood glucose (wearable and finger stick) and blood pressure readings, as well as body weight measurements using a collection of devices. Collectively this suite of platforms and approaches were used to monitor metabolic switching from glucose to ketones as energy sources-a process associated with potential cardio- and neuroprotective functions. In addition to longitudinal biomarker dynamics, this work discusses user perspectives on the potential role of harnessing digital devices to these dynamics as potential gamification factors, as well as considerations for the role of biomarker monitoring in health regimen development, user stratification, and potentially informing downstream population-scale studies to address metabolic disease, healthy aging and longevity, among other indications.

It's About Timing: Contrasting the Metabolic Effects of Early vs. Late Time-Restricted Eating in Humans

PURPOSE OF REVIEW

Time-restricted eating (TRE), a form of intermittent fasting, restricts feeding time across the day, imposing a daily 'eating window'. The time of day when the eating window occurs could result in differential metabolic effects. Here, we describe recent intervention studies in humans assessing the metabolic consequences of an early- (i.e., eating window starting in the early morning) vs. late (i.e., eating window starting after midday)-TRE protocol.

RECENT FINDINGS

Well-controlled studies indicate that both TRE protocols effectively reduce body weight and improve altered glucose metabolism, lipid profile, inflammation, or blood pressure levels. An early-TRE (e-TRE) might have a further positive impact on improving blood glucose, insulin levels, and insulin resistance. However, the studies directly assessing the metabolic consequences of an early- vs. late-TRE have shown dissimilar findings, and more well-controlled clinical trials are needed on the metabolic benefits of these two types of TRE. Evidence suggests that an e-TRE might have enhanced metabolic results, particularly regarding glucose homeostasis. More long-term studies, including larger sample sizes, are needed to assess the metabolic, circadian, and adherence benefits, together with socio-cultural acceptance of both TRE approaches.

Advances in Gut Microbiota-Targeted Therapeutics for Metabolic Syndrome

Previous investigations have illuminated the significant association between the gut microbiome and a broad spectrum of health conditions, including obesity, diabetes, cardiovascular diseases, and psychiatric disorders. Evidence from certain studies suggests that dysbiosis of the gut microbiota may play a role in the etiology of obesity and diabetes. Moreover, it is acknowledged that dietary habits, pharmacological interventions, psychological stress, and other exogenous factors can substantially influence the gut microbial composition. For instance, a diet rich in fiber has been demonstrated to increase the population of beneficial bacteria, whereas the consumption of antibiotics can reduce these advantageous microbial communities. In light of the established correlation between the gut microbiome and various pathologies, strategically altering the gut microbial profile represents an emerging therapeutic approach. This can be accomplished through the administration of probiotics or prebiotics, which aim to refine the gut microbiota and, consequently, mitigate the manifestations of associated diseases. The present manuscript evaluates the recent literature on the relationship between gut microbiota and metabolic syndrome published over the past three years and anticipates future directions in this evolving field.

Effects of Intermittent Energy Restriction Compared with Those of Continuous Energy Restriction on Body Composition and Cardiometabolic Risk Markers - A Systematic Review and Meta-Analysis of Randomized Controlled Trials in Adults

The interest in intermittent energy restriction (IER) diets as a weight-loss approach is increasing. Different IER protocols exist, including time-restricted eating (TRE), alternate-day fasting (ADF), and the 5:2 diet. This meta-analysis compared the effects of these IER diets with continuous energy restriction (CER) on anthropometrics and cardiometabolic risk markers in healthy adults. Twenty-eight trials were identified that studied TRE (k = 7), ADF (k = 10), or the 5:2 diet (k = 11) for 2-52 wk. Energy intakes between intervention groups within a study were comparable (17 trials), lower in IER (5 trials), or not reported (6 trials). Weighted mean differences (WMDs) were calculated using fixed- or random-effects models. Changes in body weight [WMD: -0.42 kg; 95% confidence interval (CI): -0.96 to 0.13; P = 0.132] and fat mass (FM) (WMD: -0.31 kg; 95% CI: -0.98 to 0.36; P = 0.362) were comparable when results of the 3 IER diets were combined and compared with those of CER. All IER diets combined reduced fat-free mass (WMD: -0.20 kg; 95% CI: -0.39 to -0.01; P = 0.044) and waist circumference (WMD: -0.91 cm; 95% CI: -1.76 to -0.06; P = 0.036) more than CER. Effects on body mass index [BMI (kg/m2)], glucose, insulin, homeostatic model assessment for insulin resistance (HOMA-IR), serum lipid and lipoprotein concentrations, and blood pressure did not differ. Further, TRE reduced body weight, FM, and fat-free mass more than CER, whereas ADF improved HOMA-IR more. BMI was reduced less in the 5:2 diet compared with CER. In conclusion, the 3 IER diets combined did not lead to superior improvements in anthropometrics and cardiometabolic risk markers compared with CER diets. Slightly greater reductions were, however, observed in fat-free mass and waist circumference. To what extent differences in energy intakes between groups within studies may have influenced these outcomes should be addressed in future studies.

Intermittent fasting favorably modulates adipokines and potentially attenuates atherosclerosis

Adipose tissue is now recognized as an endocrine organ that secretes bioactive molecules called adipokines. These biomolecules regulate key physiological functions, including insulin sensitivity, energy metabolism, appetite regulation, endothelial function and immunity. Dysregulated secretion of adipokines is intimately associated with obesity, and translates into increased risk of obesity-related cardiovasculo-metabolic diseases. In particular, emerging evidence suggests that adipokine imbalance contributes to the pathogenesis of atherosclerosis. One of the promising diet regimens that is beneficial in the fight against obesity and cardiometabolic disorders is intermittent fasting (IF). Indeed, IF robustly suppresses inflammation, meditates weight loss and mitigates many aspects of the cardiometabolic syndrome. In this paper, we review the main adipokines and their role in atherosclerosis, which remains a major contributor to cardiovascular-associated morbidity and mortality. We further discuss how IF can be employed as an effective management modality for obesity-associated atherosclerosis. By exploring a plethora of the beneficial effects of IF, particularly on inflammatory markers, we present IF as a possible intervention to help prevent atherosclerosis.

Beta-cell function in type 2 diabetes (T2DM): Can it be preserved or enhanced?

Type 2 diabetes (T2DM) is a complex metabolic disorder manifested by hyperglycemia, insulin resistance, and deteriorating beta-cell function. A way to prevent progression of the disease might be to enhance beta-cell function and insulin secretion. However, most previous studies examined beta-cell function while patients were using glycemia-lowering agents without an adequate period off medications (washout). In the present review we focus on studies with a washout period. We performed a literature search (2010 to June 2021) using beta-cell function and enhancement. The evidence shows that beta-cell function can be enhanced. Bariatric surgery and very low calorie diets show improvement in beta-cell function in many individuals. In addition, use of glucagon-like peptide-1 receptor agonists for prolonged periods (3 years or more) can also lead to improvement of beta-cell function. Further research is needed to understand the mechanisms leading to improved beta-cell function and identify agents that could enhance beta-cell function in patients with T2DM.

Efficacy of Fasting in Type 1 and Type 2 Diabetes Mellitus: A Narrative Review

Over the last decade, studies suggested that dietary behavior modification, including fasting, can improve metabolic and cardiovascular markers as well as body composition. Given the increasing prevalence of people with type 1 (T1DM) and type 2 diabetes mellitus (T2DM) and the increasing obesity (also in combination with diabetes), nutritional therapies are gaining importance, besides pharmaceutical interventions. Fasting has demonstrated beneficial effects for both healthy individuals and those with metabolic diseases, leading to increased research interest in its impact on glycemia and associated short- and long-term complications. Therefore, this review aimed to investigate whether fasting can be used safely and effectively in addition to medications to support the therapy in T1DM and T2DM. A literature search on fasting and its interaction with diabetes was conducted via PubMed in September 2022. Fasting has the potential to minimize the risk of hypoglycemia in T1DM, lower glycaemic variability, and improve fat metabolism in T1DM and T2DM. It also increases insulin sensitivity, reduces endogenous glucose production in diabetes, lowers body weight, and improves body composition. To conclude, fasting is efficient for therapy management for both people with T1DM and T2DM and can be safely performed, when necessary, with the support of health care professionals.

Time-restricted eating (16/8) and energy-restricted diet: effects on diet quality, body composition and biochemical parameters in healthy overweight females

BACKGROUND

Time-restricted eating (TRE) is a current popular dietary strategy for noncommunicable diseases. However, studies demonstrated contradictory results for it and in all dietary strategies, diet quality is an the important part of the well-being. Our study aimed to investigate the effect of TRE and energy-restricted diet (ERD) on the nutritional status and diet quality of individuals.

METHODS

This pilot study was completed 23 healthy overweight female. Anthropometric and body composition measurements of individuals were taken. The energy expenditure was measured using indirect calorimetry. Blood pressure and heart rate measurements were made. Biochemical parameters were evaluated and food consumption were taken. The quality of dietary intake was assessed using the Healthy Eating Index (HEI) -2015. The physical activity levels of the individuals were estimated using the physical activity record. The Statistical Package for the Social Sciences (version 22.0) software was used for all analyses. A p-value of less than 0.05 was considered to be statistically significant.

RESULTS

After 8 weeks of intervention, while no change was observed in the diet quality of the individuals in the TRE group (p > 0.05), a significant increase was found in the diet quality score of the individuals in the ERD group (p < 0.05). There was a 3.2% and 5.5% decrease in body weight of individuals in the TRE and ERD groups, respectively (p < 0.05). While no significant change was observed in the body fat percentage of individuals in the TRE group (p > 0.05), a 7.1% decrease was observed in the ERD group (p < 0.05). A statistically significant decrease was found in the total cholesterol (3.7%) in the ERD group, and in the total cholesterol (6.7%) and low density lipoprotein cholesterol (LDL-C) (6.5%) in the TRE group. In addition, a statistically significant increase was found in adiponectin (77.3%) and total antioxidant status (TAS) (13.2%) in the ERD group.

CONCLUSION

Energy-restricted diet yielded better results in weight loss and improvement of body composition and diet quality compared to TRE. Also, a decrease in total cholesterol level was found in the ERD group. However, more studies should be done with longer follow-ups and high sample sizes are very important in terms of creating public health-based recommendations.

Intermittent fasting alleviates type 1 diabetes-induced cognitive dysfunction by improving the frontal cortical metabolic disorder

Intermittent fasting (IF) is an ecological strategy to control various metabolic disorder symptoms, but its protective effect on type 1 diabetes (T1D)-induced cognitive dysfunction and the underlying mechanisms remain poorly defined. Herein, we examined the efficacy of IF in altering the behaviors and brain metabolome in T1D mice and investigated the potential molecular mechanisms. We demonstrated that IF remarkably improved frontal cortical-dependent memory in T1D mice and reduced the loss of neuronal cells. Metabolomics and targeted mass spectrometry assay showed that IF reprogrammed the frontal cortical metabolome composition, including activated the aspartate and glutamate pathway and reversed glycerophospholipid and sphingolipid depositions in T1D mice. Mechanistically, IF attenuated the levels of oxidative stress proteins, such as NOX2, NOX4, 8-OHdG, 4-HNE, and inhibited the levels of pro-apoptotic factors Bax and cleaved Caspase-3, finally improved the memory ability of T1D mice. In vitro studies confirmed the protective effect of the supplemented N-acetylaspartate, a pivotal metabolite involved in IF-regulated T1D-induced cognitive dysfunction, in high glucose-stimulated SH-SY5Y cells by eliminating toxic lipids accumulation, oxidative stress and apoptosis. To conclude, the frontal cortical metabolites mediated the protective effects of IF against T1D-induced cognitive dysfunction by attenuating oxidative stress and apoptotic signaling. Thus, IF can be a potential therapeutic strategy for T1D-induced cognitive dysfunction.

Finding balance: understanding the energetics of time-restricted feeding in mice

Over the course of mammalian evolution, the ability to store energy likely conferred a survival advantage when food became scarce. A long-term increase in energy storage results from an imbalance between energy intake and energy expenditure, two tightly regulated parameters that generally balance out to maintain a fairly stable body weight. Understanding the molecular determinants of this feat likely holds the key to new therapeutic development to manage obesity and associated metabolic dysfunctions. Time-restricted feeding (TRF), a dietary intervention that limits feeding to the active phase, can prevent and treat obesity and metabolic dysfunction in rodents fed a high-fat diet, likely by exerting effects on energetic balance. Even when body weight is lower in mice on active-phase TRF, food intake is generally isocaloric as compared with ad libitum fed controls. This discrepancy between body weight and energy intake led to the hypothesis that energy expenditure is increased during TRF. However, at present, there is no consensus in the literature as to how TRF affects energy expenditure and energy balance as a whole, and the mechanisms behind metabolic adaptation under TRF are unknown. This review examines our current understanding of energy balance on TRF in rodents and provides a framework for future studies to evaluate the energetics of TRF and its molecular determinants.

Prognostic Value of Histological and Immunohistochemical Data in Diabetic Foot Ulcers

Diabetic foot ulcers are an extremely urgent medical and social problem throughout the world. The purpose of this study was to analyse the histological and immunohistochemical features of tissues and cells of different sections of wounds taken during the primary surgical treatment of chronic wounds in patients with diabetic foot syndrome with favourable and unfavourable outcomes.

MATERIAL AND METHODS

A clinical prospective observational study of the treatment outcomes of fifty-three patients with diabetic foot ulcers hospitalized twice in one specialized centre over the course of the year was conducted. The analysis of histological and immunohistochemical data of the tissues of the edges and the centre of the ulcer taken during the primary surgical treatment was performed. While performing histological analyses of wound tissues, special attention was given to the determination of cellular characteristics of leukocyte-necrotic masses, granulation tissue, and loose and dense connective tissue. Immunohistochemistry was performed using a set of monoclonal antibodies, allowing verification of neutrophilic leukocytes, fibroblasts, and endothelial cells.

RESULTS

Unfavourable outcomes (amputation, reamputation, death from cardiovascular diseases, nonhealing ulcer within a year) were registered in 52.8% of cases. Uniform distribution of neutrophils and endothelial cell fibroblasts in all parts of the wound was recorded in patients with a favourable outcome. An unfavourable outcome was predetermined by the uneven content of these cells with a significant increase in neutrophilic leukocytosis in the bottom of the wounds, as well as a significant decrease in the number of fibroblasts and endotheliocytes in the centre of the wounds.

CONCLUSIONS

The datasets obtained during primary surgical treatment are extremely informative to predict the outcome of the treatment of diabetic foot ulcers and indicate more active surgical strategies with the potential to reduce the treatment time, increase its effectiveness, and eventually make the treatment cost-effective.

Effects of an Intermittent Fasting 5:2 Plus Program on Body Weight in Chinese Adults with Overweight or Obesity: A Pilot Study

To retrospectively review the efficacy of intermittent fasting 5:2 plus program (30% of energy requirements on fast days and 70% of energy requirements on nonfasting days) in Chinese patients with overweight or obesity. This retrospective cohort study evaluated weight loss outcomes of patients treated with 12 weeks weight loss program in clinic. Adults with overweight or obesity participated in intermittent fasting 5:2 plus, daily calorie restriction (70% of energy requirements every day) or daily calorie restriction with meal replacement (70% of energy requirements every day, partly provided with high-protein meal replacement) programs for 12 weeks. The primary objective was to compare the weight loss of three groups. The primary outcome measure was the change in the % total weight loss. A total of 131 patients (35.3 ± 10.1 years; 81.7% female) were included, and the mean weight loss was 7.8 ± 4.4% after 12 weeks. The intermittent fasting 5:2 plus group (n = 42) achieved 9.0 ± 5.3% weight loss, compared with 5.7 ± 3.7% in the daily calorie restriction group (n = 41) (p < 0.001) and 8.6 ± 3.5% in the meal replacement group (n = 48) (p = 0.650). A total of 85.7% of patients in the intermittent fasting 5:2 plus group lost more than 5% body weight, vs. 58.5% in the daily calorie restriction group (p = 0.008), and 45.2% lost more than 10% body weight, vs. 14.6% in the daily calorie restriction group (p = 0.005). No serious adverse events were reported in the three groups. The intermittent fasting 5:2 plus program more effectively led to weight loss than daily calorie restriction in the short-term in Chinese patients with overweight or obesity. A longer-term prospective randomized controlled trial is needed.

Alternate day fasting on subjective feelings of appetite and body weight for adults with overweight or obesity: a systematic review

Alternate day fasting (ADF) with consumption of calories up to 25 % of the daily energy intake on fast days is one of the most used intermittent fasting regimens and promoted as a promising, alternative approach for treating obesity. Feelings of appetite are critical for adherence to dietary approaches, and therefore the success of dietary interventions. This systematic review aimed to assess the effects of a minimum of 8 weeks of ADF on subjective feelings of appetite and body weight for adults with overweight and obesity. We conducted the review in accordance with the Cochrane guidelines, including systematic searches in four databases. Because of the high level of clinical and methodological heterogeneity, a narrative approach was used to synthesise the results. Eight studies with a total of 456 participants met the eligibility criteria: three randomised controlled trials and five uncontrolled before-after studies. Seven of the studies had high risk of bias. Feelings of appetite were assessed by hunger in eight studies, fullness in seven studies, satisfaction in four studies and desire to eat in one study. All the studies assessed weight loss. The certainty of the evidence was rated low or very low for all outcomes, thus no firm conclusions can be drawn about the potential benefits of ADF on subjective feelings of appetite and body weight. Despite the high interest in ADF, good quality evidence is still needed to determine its effectiveness and if offered in clinical practice, ADF should be offered cautiously while concomitantly evaluated.

Prediabetes and osteoporotic fracture risk: A meta-analysis of prospective cohort studies

BACKGROUND

Diabetes confers an increased risk of fracture. However, whether prediabetes is also a risk factor of osteoporotic fracture has not been comprehensively examined. We performed a meta-analysis to evaluate the relationship between prediabetes and osteoporotic fracture risk.

METHODS

This meta-analysis included relevant prospective cohort studies from Medline, Embase, and Web of Science databases. A random-effect model after incorporation of the intra-study heterogeneity was selected to pool the results. Subgroup analyses were applied to evaluate the influences of study characteristics on relationship between prediabetes and osteoporotic fracture risk.

RESULTS

Eight studies including 33,136 community dwelling adult patients were included, and 7429 (22.4%) patients were prediabetic. Prediabetes was not independently associated with a higher risk of osteoporotic fracture compared with normoglycemia (adjusted risk ratio: 1.03, 95% confidence interval: 0.88-1.21, P = 0.69, I²  = 42%). Sensitivity limited to the elderly population showed consistent results (RR: 1.10, 95% CI: 0.91-1.24, P = 0.15, I²  = 0%). Subgroup analysis suggested that prediabetes defined by HbA1c (approximately 5.7%-6.4%) was associated with a higher risk of osteoporotic fracture (RR: 1.24, 95% CI: 1.01-1.53, P = 0.04), but not that defined by impaired fasting glucose or impaired glucose tolerance (P = 0.60). Sex, follow-up duration, and adjustment of bone mineral density did not significantly affect the outcome.

CONCLUSIONS

Current evidence does not support that prediabetes is independently associated with osteoporotic fracture risk. Different definitions of prediabetes may affect the association between prediabetes and osteoporotic fracture risk.

Prediabetes and the incidence of dementia in general population: a systematic review and meta-analysis of prospective studies

BACKGROUND

Continuous hyperglycaemia has been related with dementia. However, it remains unclear whether prediabetes poses a higher risk of dementia. A meta-analysis was therefore conducted to comprehensively investigate the possible role of prediabetes as a risk factor of dementia.

METHODS

Prospective cohort studies reporting the association of prediabetes and dementia were identified from PubMed, Web of Science, and Embase databases. A random-effects model was applied to combine the results by incorporating the influence of heterogeneity. Subgroup analyses were also conducted to explore the influences of study features on the relationship. Sensitivity analysis re-estimated the combined effect size after excluding single studies separately to explore the robustness of the results.

RESULTS

Nine studies involving 29 986 adults from the general population, 6265 (20.9%) of whom had prediabetes, were included. It was shown that prediabetes was not independently associated with a higher incidence of dementia compared with normoglycaemia (adjusted risk ratio (RR): 1.01, 95% confidence interval (CI): 0.85-1.21, P = 0.89, I²  = 39%). Subgroup analyses according to the definitions of prediabetes, follow-up duration, method for diagnosis of dementia, and quality score produced similar findings (P for all subgroup differences >0.05). In addition, prediabetes was not independently associated with the incidence of Alzheimer's disease (RR: 1.24, 95% CI: 0.98-1.56, P = 0.07, I²  = 0%) or vascular dementia (RR: 1.16, 95% CI: 0.70-1.92, P = 0.56, I²  = 0%). Different definitions of prediabetes have the potential to influence the results, as reflected in the subgroup analysis for Alzheimer's disease (RR: 1.30, 95% CI: 1.06-1.60, P = 0.01, I²  = 0%).

CONCLUSIONS

Prediabetes may not be an independent risk factor of all-cause dementia or vascular dementia in the general adult population. However, changing the definition of prediabetes may have an impact on the outcome for Alzheimer's disease.

Effect of 5:2 Fasting Diet on Liver Fat Content in Patients with Type 2 Diabetic with Nonalcoholic Fatty Liver Disease

Background: The prevalence of nonalcoholic fatty liver disease (NAFLD) is rapidly growing in China, especially in patients with type 2 diabetes mellitus (T2DM). Weight loss strategies have been shown to treat NAFLD effectively. We conducted a 24-week, prospective, randomized study in T2DM patients with NAFLD to evaluate the effects of a 5:2 fasting diet on liver fat content. Methods: Sixty-one T2DM patients with NAFLD were enrolled and randomly divided into a 5:2 fasting diet intervention group (5:2 diet group, n = 31) and 1.8 mg/day liraglutide intervention group (Lira group, n = 30). The study was performed for 24 weeks. Data of the body weight, waist circumference, plasma lipids and glucose profile, fasting plasma insulin, and liver function parameters were collected. Controlled attenuation parameter (CAP) was measured to assess the liver fat content. Superoxide dismutase (SOD) and malondialdehyde (MDA) were measured to evaluate oxidative stress status. Results: At 24 weeks after intervention, compared with those at baseline, CAP was significantly decreased in both the 5:2 diet group and Lira group, which was 7.4% and 5.5%, respectively. Body weight, plasma lipids and glucose profile, and liver function parameters improved significantly, while homeostasis model assessment-β (HOMA-β) was significantly increased in both groups (all P < 0.05). Stepwise linear regression showed that increased HOMA-β and SOD, as well as reduced body mass index (BMI), were the independent predictors of CAP decrease in the Lira group (P = 0.000, 0.000, 0.015). In contrast, reduced BMI and MDA were the independent influencing factors of CAP decrease in the 5:2 diet group (P = 0.011, 0.043). The common side effects in the 5:2 diet group were hunger (60%), weakness (10%), and constipation (0.3%). Conclusions: A 5:2 fasting diet achieved comparable effects with liraglutide on liver fat content in patients with T2DM with NAFLD by reducing BMI and oxidative stress. Both treatment strategies were safe and effective for glucose control.

The importance of AMPK in obesity and chronic diseases and the relationship of AMPK with nutrition: a literature review

This review will examine the role of 5'-adenosine monophosphate-activated protein kinase (AMPK) in the treatment of obesity, medical nutrition and chronic diseases, and its relationship with nutrition. In the literature, the number of studies examining the direct relationship of AMPK with nutrition is negligible. For this reason, information on the subject has been compiled from all the studies that can be accessed by searching the terms AMPK and disease, AMPK and health, AMPK and exercise, AMPK and nutrition. It can be stated that AMPK is inhibited in many pathological conditions such as inflammation, diabetes, aging and cancer, and AMPK activation has positive effects in many diseases such as insulin resistance, diabetes, obesity, cancer and Alzheimer's. When the relationship between nutrition and AMPK is examined, it is seen that food intake inhibits AMPK, but especially high-carbohydrate and fatty diets are more effective at this point. In addition, high fructose corn sirup and long chain saturated fatty acids increased by consumption of industrial foods and frequent meals appear to be an inactivator for AMPK. For AMPK activation in medical nutrition therapy, it is recommended to use methods such as evening fasting and intermittent fasting, taking into account the human circadian rhythm.

Is Time-Restricted Eating Safe in the Treatment of Type 2 Diabetes?-A Review of Intervention Studies

Time-restricted eating (TRE) has been shown to improve body weight and glucose metabolism in people at high risk of type 2 diabetes. However, the safety of TRE in the treatment of type 2 diabetes is unclear. We investigated the safety of TRE interventions in people with type 2 diabetes by identifying published and ongoing studies. Moreover, we identified the commonly used antidiabetic drugs and discussed the safety of TRE in people with type 2 diabetes considering the use of these drugs. In addition, we addressed the research needed before TRE can be recommended in the treatment of type 2 diabetes. A literature search was conducted to identify published (MEDLINE PubMed) and ongoing studies (ClinicalTrials.gov) on TRE in people with type 2 diabetes. To assess the usage of antidiabetic drugs and to discuss pharmacodynamics and pharmacokinetics in a TRE context, the most used antidiabetic drugs were identified and analysed. Statistics regarding sale of pharmaceuticals were obtained from MEDSTAT.DK which are based on data from the national Register of Medicinal Product Statistics, and from published studies on medication use in different countries. Four published studies investigating TRE in people with type 2 diabetes were identified as well as 14 ongoing studies. The completed studies suggested that TRE is safe among people with type 2 diabetes. Common antidiabetic drugs between 2010 and 2019 were metformin, insulin, dipeptidyl peptidase-4 inhibitors, glucagon-like peptide-1 receptor agonists, sulfonylureas, and sodium-glucose cotransporter-2 inhibitors. Existing studies suggest that TRE is not associated with major safety issues in people with type 2 diabetes as long as medication is monitored and adjusted. However, because of low generalisability of the few studies available, more studies are needed to make concrete recommendations regarding efficacy and safety of TRE in people with type 2 diabetes.

Effects of Intermittent Fasting in Human Compared to a Non-intervention Diet and Caloric Restriction: A Meta-Analysis of Randomized Controlled Trials

Background

The popularity of applying intermittent fasting (IF) has increased as more and more people are trying to avoid or alleviate obesity and metabolic disease. This study aimed to systematically explore the effects of various IF in humans.

Methods

The randomized controlled trials (RCTs) related to IF vs. non-intervention diet or caloric restriction (CR) were retrieved in PubMed, Web of Science, Cochrane Library database, and Embase. Extraction outcomes included, but were not limited to, weight, body mass index (BMI), waist circumference (WC), fasting glucose, and triglyceride (TG).

Results

This study includes 43 RCTs with 2,483 participants. The intervention time was at least 1 month, and the median intervention time was 3 months. Contrasting results between IF and non-intervention diet showed that participants had lower weight (weighted mean difference (WMD) = 1.10, 95% CI: 0.09–2.12, p = 0.03) and BMI after IF (WMD = 0.38, 95% CI: 0.08–0.68, p = 0.01). The WC of participants after IF decreased significantly compared with the non-intervention diet (WMD = 1.02, 95% CI: 0.06–1.99, p = 0.04). IF regulated fat mass (FM) more effectively than non-intervention diet (WMD = 0.74, 95% CI: 0.17–1.31, p = 0.01). The fat-free mass of people after IF was higher (WMD = −0.73, 95% CI: (−1.45)–(−0.02), p = 0.05). There was no difference in fasting blood glucose concentrations between participants in the after IF and non-intervention diet groups. The results of insulin concentrations and HOMA-IR, though, indicated that IF was significantly more beneficial than non-intervention diet (standard mean difference (SMD) = −0.21, 95% CI: 0.02–0.40, p = 0.03, and WMD = 0.35, 95% CI: 0.04–0.65, p = 0.03, respectively). Cholesterol and TG concentrations in participants after IF were also lower than that after a nonintervention diet (SMD = 0.22, 95% CI: 0.09–0.35, p = 0.001 and SMD = 0.13, 95% CI: 0.00–0.26, p = 0.05, respectively). IF outcomes did not differ from CR except for reduced WC.

Conclusion

Intermittent fasting was more beneficial in reducing body weight, WC, and FM without affecting lean mass compared to the non-intervention diet. IF also effectively improved insulin resistance and blood lipid conditions compared with non-intervention diets. However, IF showed less benefit over CR.

Meal Timing, Meal Frequency and Metabolic Syndrome

Individuals with metabolic syndrome have increased risk for developing health conditions, including cardiovascular diseases and stroke. Modifiable risk factors, such as exercise and diet, are key components in the prevention and control of metabolic syndrome. Specifically, dietary patterns and habits are extremely successful in controlling more than one of the metabolic syndrome risk factors. Meal timing and frequency have been associated with type 2 diabetes, cardiovascular diseases, and other chronic conditions. However, there is limited evidence linking metabolic syndrome to meal timing and meal frequency. This review summarizes and discusses how meal timing and frequency impact metabolic outcomes in adults.

Scientific Evidences of Calorie Restriction and Intermittent Fasting for Neuroprotection in Traumatic Brain Injury Animal Models: A Review of the Literature

It has widely been accepted that food restriction (FR) without malnutrition has multiple health benefits. Various calorie restriction (CR) and intermittent fasting (IF) regimens have recently been reported to exert neuroprotective effects in traumatic brain injury (TBI) through variable mechanisms. However, the evidence connecting CR or IF to neuroprotection in TBI as well as current issues remaining in this research field have yet to be reviewed in literature. The objective of our review was therefore to weigh the evidence that suggests the connection between CR/IF with recovery promotion following TBI. Medline, Google Scholar and Web of Science were searched from inception to 25 February 2022. An overwhelming number of results generated suggest that several types of CR/IF play a promising role in promoting post-TBI recovery. This recovery is believed to be achieved by alleviating mitochondrial dysfunction, promoting hippocampal neurogenesis, inhibiting glial cell responses, shaping neural cell plasticity, as well as targeting apoptosis and autophagy. Further, we represent our views on the current issues and provide thoughts on the future direction of this research field.

Hepatic Suppression of Mitochondrial Complex II Assembly Drives Systemic Metabolic Benefits

Alternate day fasting (ADF), the most popular form of caloric restriction, has shown to improve metabolic health in preclinical subjects, while intrinsic network underpinning the process remains unclear. Here, it is found that liver undergoes dramatic metabolic reprogramming during ADF, accompanied surprisingly with unique complex II dysfunction attributing to suspended complex II assembly via suppressing SDHAF4, a recently identified assembly factor. Despite moderate mitochondrial complex II dysfunction, hepatic Sdhaf4 knockout mice present intriguingly improved glucose tolerance and systemic insulin sensitivity, consistent with mice after ADF intervention. Mechanistically, it is found that hepatocytes activate arginine-nitric oxide (NO) biosynthesis axle in response to complex II and citric acid cycle dysfunction, the release of NO from liver can target muscle and adipocytes in addition to its autocrine action for enhanced insulin sensitivity. These results highlight the pivotal role of liver in ADF-associated systemic benefits, and suggest that targeting hepatic complex II assembly can be an intriguing strategy against metabolic disorders.

Association Between Prediabetes and Osteoarthritis: A Meta-Analysis

Some studies have suggested that diabetes may be a risk factor for osteoarthritis. However, whether prediabetes is also associated with osteoarthritis has not been comprehensively examined. We performed a meta-analysis to evaluate the relationship between prediabetes and osteoarthritis. This meta-analysis included relevant observational studies from Medline, Embase, and Web of Science databases. A random-effect model after incorporation of the intra-study heterogeneity was selected to pool the results. Ten datasets from six observational studies were included, which involved 41 226 general adults and 10 785 (26.2%) of them were prediabetic. Pooled results showed that prediabetes was not independently associated with osteoarthritis [risk ratio (RR): 1.07, 95% confidence interval (CI): 1.00 to 1.14, p=0.06, I²=0%]. Sensitivity limited to studies with adjustment of age and body mass index showed consistent result (RR: 1.06, 95% CI: 0.99 to 1.14, p=0.09, I²=0%). Results of subgroup analyses showed that prediabetes was not associated with osteoarthritis in cross-sectional or cohort studies, in studies including Asian or non-Asian population, or in studies with different quality scores (p for subgroup difference>0.10). Besides, prediabetes was not associated with osteoarthritis in men or in women, in studies with prediabetes defined as impaired fasting glucose, impaired glucose tolerance, or HbA1c (approximately 39-46 mmol/mol). Moreover, prediabetes was not associated with overall osteoarthritis, and knee or hip osteoarthritis. Current evidence does not support that prediabetes is independently associated with osteoarthritis in adult population.

Association Between Prediabetes and Retinopathy: A Meta-Analysis

Diabetes confers an increased risk of microvascular complications, including retinopathy. However, whether prediabetes is also related to retinopathy has not been comprehensively examined. We performed a meta-analysis to evaluate the relationship between prediabetes and retinopathy. This meta-analysis included relevant observational studies from Medline, Embase, and Web of Science databases. A random-effect model after incorporation of the intra-study heterogeneity was selected to pool the results. Subgroup analyses were applied to evaluate the influences of study characteristics on relationship. Nine cross-sectional studies including 14 751 community dwelling adult participants were included; 3847 (26.1%) of them were prediabetic. Results showed that prediabetes was associated with a higher prevalence of retinopathy compared to normoglycemia [odds ratio (OR): 1.55, 95% confidence interval (CI): 1.10-2.20, p=0.01, I²=34%]. Sensitivity analysis by excluding one study at a time showed consistent result (OR: 1.35 to 1.73, p all<0.05). Subgroup analysis showed study characteristics such as definition of prediabetes, country of study, sample size, mean age of participants, or univariate or multivariate analyses may not significantly affect the association (p for subgroup difference all>0.05). Current evidence suggests that patients with prediabetes may be associated with higher prevalence of retinopathy as compared to those with normoglycemia. Although prospective cohort studies are needed to validate these findings, results of our meta-analysis highlighted the importance of early prevention of retinopathy in patients with prediabetes.

Loss of Sirt6 in adipocytes impairs the ability of adipose tissue to adapt to intermittent fasting

Intermittent fasting (IF) is gaining popularity for its effectiveness in improving overall health, including its effectiveness in achieving weight loss and euglycemia. The molecular mechanisms of IF, however, are not well understood. This study investigated the relationship between adipocyte sirtuin 6 (Sirt6) and the metabolic benefits of IF. Adipocyte-specific Sirt6-knockout (aS6KO) mice and wild-type littermates were fed a high-fat diet (HFD) ad libitum for four weeks and then subjected to 12 weeks on a 2:1 IF regimen consisting of two days of feeding followed by one day of fasting. Compared with wild-type mice, aS6KO mice subjected to HFD + IF exhibited a diminished response, as reflected by their glucose and insulin intolerance, reduced energy expenditure and adipose tissue browning, and increased inflammation of white adipose tissue. Sirt6 deficiency in hepatocytes or in myeloid cells did not impair adaptation to IF. Finally, the results indicated that the impaired adipose tissue browning and reduced expression of UCP1 in aS6KO mice were accompanied by downregulation of p38 MAPK/ATF2 signaling. Our findings indicate that Sirt6 in adipocytes is critical to obtaining the improved glucose metabolism and metabolic profiles conferred by IF and that maintaining high levels of Sirt6 in adipocytes may mimic the health benefits of IF.

Association between ambient particulate matter exposure and metabolic syndrome risk: A systematic review and meta-analysis

Although the association between ambient particulate matter and metabolic syndrome (MetS) has been investigated, the effect of particulate matter (PM) on MetS is inconclusive. We conducted a systematic review and meta-analysis to study the association between long-term ambient PM exposure and MetS risk. The data from five databases were extracted to analyze the association between ambient PM exposure and MetS risk. A random-effects model was performed to estimate the overall risk effect. The present systematic review and meta-analysis illustrated that an increase of 5 μg/m³ in annual PM_2.5 or PM₁₀ concentration was associated with 14% or 9% increases of MetS risk, respectively (PM_2.5, RR = 1.14, 95%CI [1.03, 1.25]; PM₁₀, RR = 1.09, 95%CI [1.00, 1.19]). The population-attributable risk (PAR) was 12.28% for PM_2.5 exposure or 8.26% for PM₁₀ exposure, respectively. There was statistical association between PM_2.5 exposure and risk of MetS in male proportion ≥50%, Asia, related disease or medication non-adjustment subgroup as well as cohort study subgroups, respectively. The significant association between PM₁₀ exposure and risk of MetS was observed in male proportion ≥50% and calories intake adjustment subgroups, respectively. Sensitivity analyses showed the robustness of our results. No publication bias was detected. In conclusion, there was positive association between long-term PM exposure and MetS risk. 12.28% of MetS risk could be attributable to PM_2.5 exposure.

Nutrition in Patients with Type 2 Diabetes: Present Knowledge and Remaining Challenges

Unhealthy behaviours, including diet and physical activity, coupled with genetic predisposition, drive type 2 diabetes (T2D) occurrence and severity; the present review aims to summarise the most recent nutritional approaches in T2D, outlining unmet needs. Guidelines consistently suggest reducing energy intake to counteract the obesity epidemic, frequently resulting in sarcopenic obesity, a condition associated with poorer metabolic control and cardiovascular disease. Various dietary approaches have been proposed with largely similar results, with a preference for the Mediterranean diet and the best practice being the diet that patients feel confident of maintaining in the long term based on individual preferences. Patient adherence is indeed the pivotal factor for weight loss and long-term maintenance, requiring intensive lifestyle intervention. The consumption of nutritional supplements continues to increase even if international societies do not support their systematic use. Inositols and vitamin D supplementation, as well as micronutrients (zinc, chromium, magnesium) and pre/probiotics, result in modest improvement in insulin sensitivity, but their use is not systematically suggested. To reach the desired goals, patients should be actively involved in the collaborative development of a personalised meal plan associated with habitual physical activity, aiming at normal body weight and metabolic control.

Efficacy of Dietary and Supplementation Interventions for Individuals with Type 2 Diabetes

The prevalence of Type 2 diabetes (T2D) is increasing, which creates a large economic burden. Diet is a critical factor in the treatment and management of T2D; however, there are a large number of dietary approaches and a general lack of consensus regarding the efficacy of each. Therefore, the purpose of this narrative review is twofold: (1) to critically evaluate the effects of various dietary strategies on diabetes management and treatment, such as Mediterranean diet, plant-based diet, low-calorie and very low-calorie diets, intermittent fasting, low-carbohydrate and very low-carbohydrate diets, and low glycemic diets and (2) to examine several purported supplements, such as protein, branched-chain amino acids, creatine, and vitamin D to improve glucose control and body composition. This review can serve as a resource for those wanting to evaluate the evidence supporting the various dietary strategies and supplements that may help manage T2D.

Metabolic syndrome and the aging retina

PURPOSE OF REVIEW

This review explores metabolic syndrome (MetS) as a risk factor that accelerates aging in retinal neurons and may contribute to the neurodegeneration seen in glaucomatous optic neuropathy (GON) and age-related macular degeneration (AMD).

RECENT FINDINGS

Both animal model experiments and epidemiologic studies suggest that metabolic stress may lead to aberrant regulation of a number of cellular pathways that ultimately lead to premature aging of the cell, including those of a neuronal lineage.

SUMMARY

GON and AMD are each leading causes of irreversible blindness worldwide. Aging is a significant risk factor in the specific retinal neuron loss that is seen with each condition. Though aging at a cellular level is difficult to define, there are many mechanistic modifiers of aging. Metabolic-related stresses induce inflammation, oxidative stress, mitochondrial dysfunction, endoplasmic reticulum stress, alterations to the unfolded protein response, defects in autophagy, alterations to the microbiome, and deposition of advanced glycation end products that can all hasten the aging process. Due to the number of variables related to metabolic health, defining criteria to enable the study of risk factors at a population level is challenging. MetS is a definable constellation of related metabolic risk factors that includes enlarged waist circumference, dyslipidemia, systemic hypertension, and hyperglycemia. MetS has been associated with both GON and AMD and may contribute to disease onset and/or progression in each disease.

Chemerin causes lipid metabolic imbalance and induces passive lipid accumulation in human hepatoma cell line via the receptor GPR1

AIMS

Chemerin is abundant in patients with high body mass index and metabolic syndrome possibly due to its activation in adipogenesis and glucose intolerance. It has reported that sera chemerin is positively associated with fatty liver with little known underlying mechanisms. Our aim is to study the role of chemerin in hepatic lipid metabolism.

MAIN METHODS

Oil Red O staining and TG quantitative assay were used to detect intracellular lipid accumulation. PCR, QPCR and western blot were applied to measure lipid metabolism-related genes, CMKLR1, GPR1 and inflammation marker genes. Luciferase reporter assay was employed to uncover the down-regulation of proximate promoter activities of CMKLR1 and GPR1 by SREBP1c. Antibody neutralization assay was used to address the effects of chemerin on hepatic lipid synthesis.

KEY FINDINGS

Over-expression of chemerin led to passive lipid accumulation, in human hepatoma cell line HepG2. The disable form of chemerin (chemerin 21-158) and active chemerin (chemerin 21-157) performed strongly effects on lipid metabolism in HepG2 cells. Heterologous expression of CMKLR1 or G-protein coupled receptor1 (GPR1) played similar roles in hepatocyte lipid metabolism as chemerin. Chemerin exerted its effects on lipid metabolism via GPR1 in HepG2 cells. Furthermore, free fatty acids and high concentration insulin inhibited chemerin expression. Consistently, the key lipogenic transcription factor Sterol regulatory element binding protein 1c suppressed chemerin mRNA expression and proximate promoter activities of CMKLR1 and GPR1.

SIGNIFICANCE

It implied the existence of negative feed-back regulation and further confirmed the involvement of chemerin in hepatic lipid metabolism.

Brain-Gut-Microbiome Interactions and Intermittent Fasting in Obesity

The obesity epidemic and its metabolic consequences are a major public health problem both in the USA and globally. While the underlying causes are multifactorial, dysregulations within the brain–gut–microbiome (BGM) system play a central role. Normal eating behavior is coordinated by the tightly regulated balance between intestinal, extraintestinal and central homeostatic and hedonic mechanisms, resulting in stable body weight. The ubiquitous availability and marketing of inexpensive, highly palatable and calorie-dense food has played a crucial role in shifting this balance towards hedonic eating through both central (disruptions in dopaminergic signaling) and intestinal (vagal afferent function, metabolic toxemia, systemic immune activation, changes to gut microbiome and metabolome) mechanisms. The balance between homeostatic and hedonic eating behaviors is not only influenced by the amount and composition of the diet, but also by the timing and rhythmicity of food ingestion. Circadian rhythmicity affects both eating behavior and multiple gut functions, as well as the composition and interactions of the microbiome with the gut. Profound preclinical effects of intermittent fasting and time restricted eating on the gut microbiome and on host metabolism, mostly demonstrated in animal models and in a limited number of controlled human trials, have been reported. In this Review, we will discuss the effects of time-restricted eating on the BGM and review the promising effects of this eating pattern in obesity treatment.

Association Between Prediabetes and Erectile Dysfunction: A Meta-Analysis

BACKGROUND

Diabetes has been associated with the increased risk of erectile dysfunction (ED). However, previous studies evaluating the association between prediabetes and ED showed inconsistent results. We performed a meta-analysis of observational studies to systematically evaluate the above association.

METHODS

Relevant observational studies were retrieved by search of PubMed, Embase, and Web of Science databases. A random-effect model which incorporated the potential intra-study heterogeneity was used for the meta-analysis. Subgroup analyses were performed to evaluate the influences of study characteristics on the outcome.

RESULTS

Nine studies (five matched case-control studies and four cross-sectional studies) were included. Age were adjusted or matched in all of the studies. Pooled results showed that compared to men with normoglycemia, men with prediabetes were associated with higher prevalence of ED (odds ratio = 1.62, 95% confidence interval: 1.28 to 2.07, P < 0.001; I² = 78%). Subgroup analyses showed that the association was not significantly affected by definition of prediabetes, diagnostic tool for ED, or controlling of additional variables besides age (both P for subgroup difference > 0.05). However, the association between prediabetes and ED seemed to be stronger in case-control studies than that in cross-sectional studies, and in studies with younger men (mean age < 50 years) than in those with older men (mean age ≥ 50 years; both P for subgroup difference < 0.05).

CONCLUSIONS

Prediabetes is associated with higher prevalence of ED, which may be independent of age of the males and may be stronger in young men.

Modulation of neural fMRI responses to visual food cues by overeating and fasting interventions: A preliminary study

Neural processing of visual food stimuli is perturbated at extremes of weight. Human fMRI studies investigating diet effects on neural processing of food cues could aid in understanding altered brain activation in conditions of under- and overnutrition. In this preliminary study, we examined brain activity changes in response to 10 days of high-calorie-diet (HCD), followed by 10 days of fasting, hypothesizing that HCD would decrease activation in homeostatic and reward regions, while fasting would increase activation in homeostatic/reward regions and decrease activation of self-control regions. Seven adults completed fMRI scanning during a food-cue paradigm (high- and low-calorie food images and nonfood objects), pre- and post-10-day HCD. Six adults completed fMRI scanning pre- and post-10-day fasting. BOLD response changes for contrasts of interest pre- versus post-intervention in regions of interest were examined (peak-level significance set at p(FWE)<0.05). BMI increased by 6.8% and decreased by 8.1% following HCD and fasting, respectively. Following HCD, BOLD response in the hypothalamus (homeostatic control), was attenuated at trend level in response to high- versus low-calorie foods. Following fasting, BOLD response to food versus objects in inhibitory-control areas (dorsolateral prefrontal cortex) was reduced, whereas the activation of homeostatic (hypothalamus), gustatory, and reward brain areas (anterior insula and orbitofrontal cortex) increased. Overfeeding and fasting for 10 days modulate brain activity in response to food stimuli, suggesting that in healthy adults, changes in energy balance affect saliency and reward value of food cues. Future studies are required to understand this interaction in states of unhealthy weight.

Type 2 Diabetes Mellitus Associated with Obesity (Diabesity). The Central Role of Gut Microbiota and Its Translational Applications

Obesity is a condition of rising prevalence worldwide, with important socioeconomic implications, being considered as a growing public health concern. Frequently, obesity brings other complications in addition to itself—like Type 2 Diabetes Mellitus (T2DM)—sharing origin, risk factors and pathophysiological mechanisms. In this context, some authors have decided to include both conditions as a unique entity known as “diabesity”. In fact, understanding diabesity as a single disease is possible to maximise the benefits from therapies received in these patients. Gut microbiota plays a key role in individual’s health, and their alterations, either in its composition or derived products are related to a wide range of metabolic disorders like T2DM and obesity. The present work aims to collect the different changes reported in gut microbiota in patients with T2DM associated with obesity and their possible role in the onset, development, and establishment of the disease. Moreover, current research lines to modulate gut microbiota and the potential clinical translation derived from the knowledge of this system will also be reviewed, which may provide support for a better clinical management of such a complex condition.