Immunomodulatory effect of a very-low-calorie ketogenic diet compared with bariatric surgery and a low-calorie diet in patients with excessive body weight

Ketogenic diet improves disease activity and cardiovascular risk in psoriatic arthritis: A proof of concept study

OBJECTIVES

Very low-calorie ketogenic diet (VLCKD) is a low-carbohydrate, low-calorie regimen that leads to rapid weight loss and may reduce inflammation. This study assessed the impact of VLCKD on anthropometric measurements, inflammatory biomarkers, metabolic health, and cardiovascular risk in psoriatic arthritis (PsA) patients moderately overweight or in class I obesity.

METHODS

A proof-of-concept single-arm monocentric study involved PsA patients undergoing a 9-week VLCKD treatment. Patients with Body Mass Index (BMI) ≥27 and <35, in stable (≥6 months) remission or low disease activity, as defined by Disease Activity in PSoriatic Arthritis (DAPSA) score, were included and underwent nutritional evaluations every 3 weeks. The study analyzed changes after the VLCKD intervention and the association between changes of anthropometric parameters and clinical and laboratory variables.

RESULTS

Twenty patients were enrolled since April 2022 and completed the study in May 2023. Median baseline BMI was 30.9 (interquartile range 29.1-33) kg/m². All participants exhibited low baseline disease activity, which correlated with BMI (Spearman's correlation coefficient (rs)=0.59,p=0.007). Following VLCKD, significant improvements were observed in all anthropometric measures (BMI -3.5[-4;-2.6]), PsA activity (DAPSA -6.1[-16.8;3.7]), cardiovascular parameters (SCORE2 index -0.2[-0.7;0.1]), insulin resistance (Homeostatic Model Assessment-Insuline Resistance -2.1[-1.1;-3.0]), and lipid profile. Most inflammatory biomarkers remained within normal limits. BMI reduction correlated with changes in DAPSA scores (rs=0.52,p=0.020). Patients with higher baseline weight or clinical activity experienced more pronounced improvements.

CONCLUSIONS

VLCKD significantly improved PsA activity and metabolic health. Patients with a higher BMI and less controlled disease are particularly motivated and could benefit more from VLCKD compared to those with lower BMI or better disease control.

Obesity-related osteopontin protein and methylation blood levels are differentially modulated by a very low-calorie ketogenic diet or bariatric surgery

BACKGROUND & AIM

Osteopontin (OPN) was proposed to play a role in the pathophysiology of obesity and related disease, such as cancer. The aims were to evaluate the expression of OPN after caloric restriction-induced weight loss in adipose tissue (AT) from an animal model of diet-induced obesity (DIO) and to reflect these results on circulating OPN levels in patients with obesity (PWO); and to explore the effect of a very low-calorie ketogenic diet (VLCKD) on the circulating protein and DNA methylation levels of OPN, compared with a balanced hypocaloric diet (LCD) or bariatric surgery (BS) in PWO.

METHODS

OPN/SPP1 expression was evaluated in subcutaneous (SAT) and visceral (VAT) AT derived from diet-induced obesity (DIO) mice and after a 4-week weight-loss protocol of calorie restriction (CR). Plasmatic OPN was also evaluated in 32 normal-weight volunteers (20 women) and 79 PWO (59 women) and after a 4-6 months follow up of a VLCKD (n = 20), BS (n = 39) or LCD (n = 20). DNA methylation levels of OPN were extracted from our Infinium HumanMethylation450 BeadChips data sets.

RESULTS

OPN levels were higher in VAT of DIO mice and plasma of PWO than in normal-weight individuals and changed after weight loss. Particularly, circulating OPN increased 2 months after BS while it decreased at maximum ketosis-induced by VLCKD. A statistically significant decrease was also observed in methylation levels at cg11226901 after VLCKD.

CONCLUSIONS

OPN levels were reduced after VLCKD and severely increased after BS. Therefore, it could be a biomarker of the obesity-related metabolic stress and could be epigenetically regulated.

Effects of Dietary Habits on Markers of Oxidative Stress in Subjects with Hashimoto's Thyroiditis: Comparison Between the Mediterranean Diet and a Gluten-Free Diet

BACKGROUND

The Mediterranean diet (MedD) exerts anti-inflammatory and anti-oxidant effects that are beneficial in autoimmune thyroid diseases (ATD). Recently, a gluten-free diet (GFD) has been proposed for non-celiac patients with Hashimoto's thyroiditis (HT), but its usefulness is under debate. The present pilot study evaluates the effects of these two dietary regimes, with a focus on redox homeostasis, in HT.

PATIENTS AND METHODS

45 euthyroid HT patients (30 F; median age 42 years) were randomly assigned to different dietary regimes: MedD (n = 15), GFD (n = 15) and free diet (FD, n = 15). Thyroid function tests, autoantibodies, and oxidative stress markers (Advanced glycation end products, AGEs; glutathione peroxidase (GPx), thioredoxin reductase (TRxR), and total plasma antioxidant activity (TEAA) were measured at baseline and after 12 weeks.

RESULTS

In the MedD group, significantly lower values of AGEs and higher values of GPX, TRX and TEAA with anti-oxidant action were detected (p < 0.05) at 12 weeks compared to baseline, and compared to the GFD and FD groups, in which the oxidative stress parameters did not change significantly (p > 0.05). No significant differences in serum levels of TSH, FT4, Ab-Tg, Ab-TPO compared to baseline were found in any group.

CONCLUSIONS

This pilot study confirms the protective effect of the MedD against oxidative stress, while a GFD does not significantly influence markers of oxidative stress and/or thyroid autoimmunity/function parameters.

A very-low-calorie ketogenic diet normalises obesity-related enhanced levels of erythropoietin compared with a low-calorie diet or bariatric surgery

PURPOSE

Nutritional ketosis synergistically with body-weight loss induced by a very-low-calorie ketogenic diet (VLCKD) has proven to be effective in improving obesity-related pathophysiology. Recently, growing attention has been focused on the relation between erythropoietin (EPO) and obesity. Thus, this study aims to investigate whether nutritional ketosis and weight loss induced by a VLCKD modify the circulating levels of EPO in patients with obesity in comparison with the effect of low-calorie diet (LCD) or bariatric surgery (BS).

METHODS

EPO levels, iron status and body composition parameters were evaluated in 72 patients with overweight or obesity and 27 normal-weight subjects at baseline and after the three different weight-reduction therapies (VLCKD, LCD and BS) in 69 patients with excess body weight. β-hydroxybutyrate levels were also measured in the VLCKD group. The follow-up was established at 2-3 months and 4-6 months.

RESULTS

It was found that EPO levels were higher in morbid obesity and correlated with higher basal weight, fat mass (FM) and fat-free mass (FFM) in the overall sample. High baseline EPO levels were also correlated with higher impact on the course of weight loss and changes in FM and FFM induced by the three weight-loss interventions. Furthermore, the VLCKD induced a decrease in EPO levels coinciding with maximum ketosis, which was maintained over time, while statistically significant changes were not observed after LCD and BS.

CONCLUSION

The obesity-related increased EPO levels are restored after VLCKD intervention at the time of maximum ketosis, suggesting a potential role of the nutritional ketosis induced by the VLCKD. Baseline EPO levels could be a biomarker of response to a weight-loss therapy.

Efficacy, Safety, and Tolerability of a Very Low-Calorie Ketogenic Diet in Women with Obesity and Symptomatic Knee Osteoarthritis: A Pilot Interventional Study

BACKGROUND/OBJECTIVES

Obesity is a major risk factor for knee osteoarthritis (OA), and weight loss is crucial for its management. This pilot study explores the effects of a Very Low-Calorie Ketogenic Diet (VLCKD) in women with obesity and symptomatic knee OA.

METHODS

Women with symptomatic knee OA and obesity, defined as a body mass index (BMI) ≥ 30 kg/m2, were eligible for the VLCKD protocol. The intervention included a ketogenic phase from baseline (T0) to the 8th week (T8), followed by a progressive reintroduction of carbohydrates over the next 12 weeks, ending at the 20th week (T20). Body mass index (BMI), the Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index, the EuroQol 5D (EQ-5D), and the 36-item Short Form Health Survey (SF-36) were assessed at all time points. Generalized estimating equations were used to analyze the association between BMI and patient-reported outcomes across the study period.

RESULTS

Twenty participants started the study, but four discontinued the intervention, with two of these being due to adverse effects. The mean age of the 16 patients who completed the 20-week program was 57.3 ± 5.5 years, and their mean BMI was 40.0 ± 4.8 kg/m2. The mean BMI significantly decreased to 37.5 ± 4.5 at T4, 36.3 ± 4.6 at T8, and 34.8 ± 4.8 at T20 (all p < 0.001 compared to baseline). The total WOMAC score improved from a mean of 43.6 ± 16.9 at T0 to 30.2 ± 12.8 at T4 (p = 0.005) and further to 24.7 ± 10.6 at T8 (p = 0.001) and to 24.8 ± 15.9 at T20 (p = 0.005). The reduction in BMI was significantly correlated with the improvements in WOMAC, EQ-5D, and SF-36 over time. No major adverse effects were observed.

CONCLUSIONS

A 20-week VLCKD in women with obesity and knee OA significantly reduced their weight and improved their outcomes, warranting further research. This trial is registered with number NCT05848544 on ClinicalTrials.gov.

The Impact of Weight Loss on Inflammation, Oxidative Stress, and Mitochondrial Function in Subjects with Obesity

Inflammation, oxidative stress, and mitochondrial function are implicated in the development of obesity and its comorbidities. The purpose of this study was to assess the impact of weight loss through calorie restriction on the metabolic profile, inflammatory and oxidative stress parameters, and mitochondrial respiration in an obese population. A total of 109 subjects underwent two cycles of a very low-calorie diet alternated with a low-calorie diet (24 weeks). We analyzed biochemical and inflammatory parameters in serum, as well as oxidative stress markers, mRNA antioxidant gene expression, and mitochondrial respiration in peripheral blood mononuclear cells (PBMCs). After the intervention, there was an improvement in both insulin resistance and lipid profiles, including cholesterol subfractions. Weight loss produced a significant reduction in mitochondrial ROSs content and an increase in glutathione levels, coupled with an enhancement in the mRNA expression of antioxidant systems (SOD1, GSR, and CAT). In addition, a significant improvement in basal oxygen consumption, maximal respiration, and ATP production was observed. These findings demonstrate that moderate weight loss can improve insulin resistance, lipid profiles and subfractions, inflammatory and oxidative stress parameters, and mitochondrial respiration. Therefore, we can affirm that dietary intervention can simultaneously achieve significant weight loss and improve metabolic profile and mitochondrial function in obesity.

Effects of Weight Loss on Key Obesity-Related Biomarkers Linked to the Risk of Endometrial Cancer: A Systematic Review and Meta-Analysis

Endometrial cancer (EC) includes various histologic types, with estrogen-dependent endometrioid carcinoma being the most common. Obesity significantly increases the risk of developing this type, especially in postmenopausal women, due to elevated estrogen production by adipocytes. This review examines the impact of weight loss from different interventions on reducing obesity-related risk factors for endometrioid EC. A systematic review and meta-analysis were conducted on three weight loss interventions: bariatric surgery, pharmacotherapy, and lifestyle changes. The effects of these interventions on inflammatory biomarkers (CRP, TNF-α, IL-6) and hormones (leptin, estrogen) were analyzed. Data from controlled studies were pooled to assess the significance of weight loss in reducing these biomarkers. Despite heterogeneity, bariatric surgery resulted in an overall 25.8% weight reduction, outperforming lifestyle and pharmacotherapy interventions. Weight loss reduced CRP levels by 33.5% and IL-6 levels by 41.9%. TNF-α levels decreased by 13% with percent weight loss over 7%. Leptin levels also decreased significantly, although the exact weight loss percentage was not statistically significant. Weight loss effectively reduces proinflammatory markers and hormones associated with increased risk of endometrioid EC. The strengths of this review include a comprehensive examination of different weight-loss interventions and a large pool of participants. However, limitations include high heterogeneity among studies and only 43% of the participants being postmenopausal. Limited data on sex hormones and racial disparities underscore the need for further research.

Investigating the Effectiveness of a Carb-Free Oloproteic Diet in Fibromyalgia Treatment

Fibromyalgia (FM), a chronic disease with a high incidence in women, poses a significant challenge for diagnosis and treatment, especially due to the absence of specific biomarkers and the multifaceted nature of its symptoms, which range from neuromuscular pain to mood disorders and intestinal dysbiosis. While diagnosis currently relies on rheumatological clinical evaluations and treatment options mainly focus on symptom management, FM seems to have possible links with systemic metabolic dysfunctions with a common inflammatory root. In this context, a new therapeutic avenue emerges: could a therapeutic nutritional approach be the missing piece of the puzzle? Indeed, diet therapies employed particularly for metabolic syndromes proved recently to be efficacious for correcting systemic dysmetabolism and a high number of chronic inflammation conditions. In particular, the very-low-calorie ketogenic diet (VLCKD) demonstrated therapeutic benefits in many disorders. In the present study, we aimed to investigate the specific effects of two dietary interventions, namely the oloproteic VLCKD and the low-glycemic insulinemic (LOGI) diet, on two groups of female FM patients (FM1 and FM2) over a 45-day period. Utilizing clinical and laboratory tests, as well as non-invasive NMR metabolomic analysis of serum, urine, and saliva samples, we sought to uncover how these dietary regimens impact the metabolic dysfunctions associated with FM.

Weight loss treatment for COVID-19 in patients with NCDs: a pilot prospective clinical trial

COVID-19 comorbid with noncommunicable chronic diseases (NCDs) complicates the diagnosis, treatment, and prognosis, and increases the mortality rate. The aim is to evaluate the effects of a restricted diet on clinical/laboratory inflammation and metabolic profile, reactive oxygen species (ROS), and body composition in patients with COVID-19 comorbid with NCDs. We conducted a 6-week open, pilot prospective controlled clinical trial. The study included 70 adult patients with COVID-19 comorbid with type 2 diabetes (T2D), hypertension, or nonalcoholic steatohepatitis (NASH).

INTERVENTIONS

a restricted diet including calorie restriction, hot water drinking, walking, and sexual self-restraint.

PRIMARY ENDPOINTS

COVID-19 diagnosis by detecting SARS-CoV-2 genome by RT-PCR; weight loss in Main group; body temperature; C-reactive protein. Secondary endpoints: the number of white blood cells; erythrocyte sedimentation rate; adverse effects during treatment; fasting blood glucose, glycosylated hemoglobin A1c (HbA1c), systolic/diastolic blood pressure (BP); blood lipids; ALT/AST, chest CT-scan. In Main group, patients with overweight lost weight from baseline (- 12.4%; P < 0.0001); 2.9% in Main group and 7.2% in Controls were positive for COVID-19 (RR: 0.41, CI: 0.04-4.31; P = 0.22) on the 14th day of treatment. Body temperature and C-reactive protein decreased significantly in Main group compared to Controls on day 14th of treatment (P < 0.025). Systolic/diastolic BP normalized (P < 0.025), glucose/lipids metabolism (P < 0.025); ALT/AST normalized (P < 0.025), platelets increased from baseline (P < 0.025), chest CT (P < 0.025) in Main group at 14 day of treatment. The previous antidiabetic, antihypertensive, anti-inflammatory, hepatoprotective, and other symptomatic medications were adequately decreased to completely stop during the weight loss treatment. Thus, the fast weight loss treatment may be beneficial for the COVID-19 patients with comorbid T2D, hypertension, and NASH over traditional medical treatment because, it improved clinical and laboratory/instrumental data on inflammation; glucose/lipid metabolism, systolic/diastolic BPs, and NASH biochemical outcomes, reactive oxygen species; and allowed patients to stop taking medications.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05635539 (02/12/2022): https://clinicaltrials.gov/ct2/show/NCT05635539?term=NCT05635539&draw=2&rank=1 .

Fabry Disease: Cardiac Implications and Molecular Mechanisms

PURPOSE OF REVIEW

This review explores the interplay among metabolic dysfunction, oxidative stress, inflammation, and fibrosis in Fabry disease, focusing on their potential implications for cardiac involvement. We aim to discuss the biochemical processes that operate in parallel to sphingolipid accumulation and contribute to disease pathogenesis, emphasizing the importance of a comprehensive understanding of these processes.

RECENT FINDINGS

Beyond sphingolipid accumulation, emerging studies have revealed that mitochondrial dysfunction, oxidative stress, and chronic inflammation could be significant contributors to Fabry disease and cardiac involvement. These factors promote cardiac remodeling and fibrosis and may predispose Fabry patients to conduction disturbances, ventricular arrhythmias, and heart failure. While current treatments, such as enzyme replacement therapy and pharmacological chaperones, address disease progression and symptoms, their effectiveness is limited. Our review uncovers the potential relationships among metabolic disturbances, oxidative stress, inflammation, and fibrosis in Fabry disease-related cardiac complications. Current findings suggest that beyond sphingolipid accumulation, other mechanisms may significantly contribute to disease pathogenesis. This prompts the exploration of innovative therapeutic strategies and underscores the importance of a holistic approach to understanding and managing Fabry disease.

Immune-Modulating Effects of Low-Carbohydrate Ketogenic Foods in Healthy Canines

Background

Ketogenic foods limit digestible carbohydrates but contain high fat, and have antioxidant and anti-inflammatory effects as well as improving mitochondrial function. β-Hydroxybutyrate (BHB), 1 of the ketone bodies, reduces the proinflammatory NLR family pyrin domain containing 3 inflammasomes, as well as chemokines in cultures.

Objectives

We assessed the immune-modulating effects of 2 low-carbohydrate (LoCHO) foods varying in protein and fat and compared their effects with a food replete with high-carbohydrate (HiCHO) in healthy canines.

Methods

Dogs were fed control food [HiCHO; ketogenic ratio (KR: 0.46) followed by LoCHO_PROT (KR: 0.97), then LoCHO_FAT (KR: 1.63) or LoCHO_FAT followed by LoCHO_PROT. Each food was fed for 5 wk, with collections in the 5th wk; 15 wk feeding total. Gene expression for circulating inflammatory cytokines from 10 dogs was assessed using the Canine RT2 Profiler polymerase chain reaction array, and fold changes were calculated using the ΔΔCt method.

Results

LoCHO_FAT significantly increased circulating β-hydroxybutyrate compared with both HiCHO and LoCHO_PROT. When compared with HiCHO, there was a significant decrease in several proinflammatory cytokines/chemokines in LoCHO_PROT and LoCHO_FAT groups, including chemokine (C-C motif) ligand (CCL)1, CCL8, CCL13, CCL17, CCL24, chemokine (C-X3-C motif) ligand 1, chemokine (C-X-C motif) receptor 1, Interleukin-10 receptor alpha ((IL)-10RA), IL-1 receptor antagonist, IL-5, and secreted phosphoprotein 1 (all P < 0.05). Interestingly, a subset of inflammatory proteins that decreased in LoCHO_PROT but not in LoCHO_FAT included IL-33, IL-6 receptor, IL-7, IL-8, Nicotinamide phosphoribosyltransferase, and tumor necrosis factor (TNF) receptor superfamily member 11B. In contrast, the decrease in inflammatory markers in LoCHO_FAT, but not in LoCHO_PROT, included complement component 5, granulocyte colony-stimulating factor or G-CSF, interferon-γ, IL-3, IL-10RB, IL-17C, Tumor necrosis factor superfamily (TNFSF)13, TNFSF13B, and TNFSF14. Decreased concentrations of selected cytokines indicate that both low-carbohydrate foods exert an anti-inflammatory effect and provide a strong rationale for testing their efficacy in dogs with inflammatory conditions.

Conclusions

Both LoCHO_PROT and LoCHO_FAT foods might be important as part of immune-modulating therapeutic nutritional strategies to reduce inflammation to maintain health in canines. Our study identifies several inflammatory genes that are reduced when fed ketogenic food that were not previously reported.

Ketogenic nutritional therapy (KeNuT)-a multi-step dietary model with meal replacements for the management of obesity and its related metabolic disorders: a consensus statement from the working group of the Club of the Italian Society of Endocrinology (SIE)-diet therapies in endocrinology and metabolism

PURPOSE

The ketogenic nutritional therapy (KeNuT) is an effective dietary treatment for patients with obesity and obesity-related comorbidities, including type 2 diabetes, dyslipidaemia, hypertension, coronary artery disease, and some type of cancers. However, to date an official document on the correct prescription of the ketogenic diet, validated by authoritative societies in nutrition or endocrine sciences, is missing. It is important to emphasize that the ketogenic nutritional therapy requires proper medical supervision for patient selection, due to the complex biochemical implications of ketosis and the need for a strict therapeutic compliance, and an experienced nutritionist for proper personalization of the whole nutritional protocol.

METHODS

This practical guide provides an update of main clinical indications and contraindications of ketogenic nutritional therapy with meal replacements and its mechanisms of action. In addition, the various phases of the protocol involving meal replacements, its monitoring, clinical management and potential side effects, are also discussed.

CONCLUSION

This practical guide will help the healthcare provider to acquire the necessary skills to provide a comprehensive care of patients with overweight, obesity and obesity-related diseases, using a multistep ketogenic dietary treatment, recognized by the Club of the Italian Society of Endocrinology (SIE)-Diet Therapies in Endocrinology and Metabolism.

Effect of a Very Low-Calorie Diet on Oxidative Stress, Inflammatory and Metabolomic Profile in Metabolically Healthy and Unhealthy Obese Subjects

The purpose of the study was to determine the impact of weight loss through calorie restriction on metabolic profile, and inflammatory and oxidative stress parameters in metabolically healthy (MHO) and unhealthy (MUHO) obese individuals. A total of 74 subjects (34 MHO and 40 MUHO) received two cycles of a very low-calorie diet, alternating with a hypocaloric diet for 24 weeks. Biochemical, oxidative stress, and inflammatory markers, as well as serum metabolomic analysis by nuclear magnetic resonance, were performed at baseline and at the end of the intervention. After the diet, there was an improvement in insulin resistance, as well as a significant decrease in inflammatory parameters, enhancing oxidative damage, mitochondrial membrane potential, glutathione, and antioxidant capacity. This improvement was more significant in the MUHO group. The metabolomic analysis showed a healthier profile in lipoprotein profile. Lipid carbonyls also decrease at the same time as unsaturated fatty acids increase. We also display a small decrease in succinate, glycA, alanine, and BCAAs (valine and isoleucine), and a slight increase in taurine. These findings show that moderate weight reduction leads to an improvement in lipid profile and subfractions and a reduction in oxidative stress and inflammatory markers; these changes are more pronounced in the MUHO population.

Lifestyle and host determinants of antitumor immunity and cancer health disparities

Lifestyle factors exert profound effects on host physiology and immunology. Disparities in cancer outcomes persist as a complex and multifaceted challenge, necessitating a comprehensive understanding of the interplay between host environment and antitumor immune responses. Determinants of health - such as obesity, diet, exercise, stress, or sleep disruption - have the potential for modification, yet some exert long-lasting effects and may challenge the notion of complete reversibility. Herein we review intersectional considerations of lifestyle immunity and the impact on tumor immunology and disparities in cancer outcomes, with a focus on obesity.

Association of adiposity and its changes over time with COVID-19 risk in older adults with overweight/obesity and metabolic syndrome: a longitudinal evaluation in the PREDIMED-Plus cohort

BACKGROUND

Cross-sectionally, older age and obesity are associated with increased coronavirus disease-2019 (COVID-19) risk. We assessed the longitudinal associations of baseline and changes in adiposity parameters with COVID-19 incidence in older adults at high cardiovascular risk.

METHODS

This analysis included 6874 men and women (aged 55-75 years) with overweight/obesity and metabolic syndrome in the PREDIMED-Plus lifestyle intervention trial for cardiovascular risk reduction. Body weight, body-mass-index (BMI), waist circumference, waist-to-height ratio (WHtR), and a body shape index (ABSI) were measured at baseline and annual follow-up visits. COVID-19 was ascertained by an independent Event Committee until 31 December 2021. Cox regression models were fitted to evaluate the risk of COVID-19 incidence based on baseline adiposity parameters measured 5-6 years before the pandemic and their changes at the visit prior to censoring.

RESULTS

At the time of censoring, 653 incident COVID-19 cases occurred. Higher baseline body weight, BMI, waist circumference, and WHtR were associated with increased COVID-19 risk. During the follow-up, every unit increase in body weight (HRadj (95%CI): 1.01 (1.00, 1.03)) and BMI (HRadj: 1.04 (1.003, 1.08)) was associated with increased COVID-19 risk.

CONCLUSIONS

In older adults with overweight/obesity, clinically significant weight loss may protect against COVID-19.

TRIAL REGISTRATION

This study is registered at the International Standard Randomized Controlled Trial (ISRCT; http://www.isrctn.com/ISRCTN89898870 ).

Interventions to Address Cardiovascular Risk in Obese Patients: Many Hands Make Light Work

Obesity is a growing public health epidemic worldwide and is implicated in slowing improved life expectancy and increasing cardiovascular (CV) risk; indeed, several obesity-related mechanisms drive structural, functional, humoral, and hemodynamic heart alterations. On the other hand, obesity may indirectly cause CV disease, mediated through different obesity-associated comorbidities. Diet and physical activity are key points in preventing CV disease and reducing CV risk; however, these strategies alone are not always sufficient, so other approaches, such as pharmacological treatments and bariatric surgery, must support them. Moreover, these strategies are associated with improved CV risk factors and effectively reduce the incidence of death and CV events such as myocardial infarction and stroke; consequently, an individualized care plan with a multidisciplinary approach is recommended. More precisely, this review explores several interventions (diet, physical activity, pharmacological and surgical treatments) to address CV risk in obese patients and emphasizes the importance of adherence to treatments.

Chronotype as a predictor of weight loss and body composition improvements in women with overweight or obesity undergoing a very low-calorie ketogenic diet (VLCKD)

BACKGROUND & AIM

Recent studies reported that chronotype play a role in the development of metabolic comorbidities and in determining dietary habits in obesity. However, little is known if chronotype could predict the efficacy of nutritional approaches for obesity. The aim of this study was to investigate whether chronotype categories can have a role in determining the efficacy of very low-calorie ketogenic diet (VLCKD) in terms of weight loss and changes of body composition in women with overweight or obesity.

METHODS

In this retrospective study we analyzed data from 248 women (BMI 36.03 ± 5.20 kg/m2, aged 38.76 ± 14.05 years) clinically referred for weight loss and who completed a VLCKD program. In all women, we assessed anthropometric parameters (weight, height, and waist circumference), body composition and phase angle (through bioimpedance analysis, Akern BIA 101) at the baseline and after 31 days of active phase of VLCKD. Chronotype score was assessed using Morningness-Eveningness questionnaire (MEQ) at baseline.

RESULTS

After 31 days of active phase of VLCKD all enrolled women experienced significant weight loss (p < 0.001) and reduction of BMI (p < 0.001), waist circumference (p < 0.001), fat mass (kg and %) (p < 0.001), and free fat mass (kg) (p < 0.001). Women with evening chronotype experienced significantly less weight loss (p < 0.001) and reduced fat mass (kg and %) (p < 0.001), increased fat free mass (kg and %) (p < 0.001) and phase angle (p < 0.001) than women with morning chronotype. In addition, chronotype score correlated negatively with percentage changes in weight (p < 0.001), BMI (p < 0.001), waist circumference (p < 0.001) and fat mass (p < 0.001) and positively with fat free mass (p < 0.001) and phase angle (p < 0.001) from baseline to the 31st day of active phase of VLCKD. Using a linear regression model, chronotype score (p < 0.001) was the main predictors of weight loss achieved with VLCKD.

CONCLUSION

Evening chronotype is associated with a lower efficacy in terms of weight loss and improvements of body composition after VLCKD in obesity.

Very low energy diets prior to bariatric surgery may reduce postoperative morbidity: a systematic review and meta-analysis of randomized controlled trials

Purpose

To optimize patients prior to bariatric surgery, very low energy diets (VLEDs) are often employed for 2-4 weeks preoperatively. They are known to result in preoperative weight loss, decrease liver volume, and decrease surgeon-perceived operative difficulty. Their impact on postoperative morbidity has been less extensively studied. We performed a focused systematic review and meta-analysis with the aim of comparing preoperative VLEDs prior to bariatric surgery with controls in terms of overall postoperative morbidity.

Methods

MEDLINE, Embase, and CENTRAL were searched from database inception to February 2023. Articles were eligible for inclusion if they were randomized controlled trials (RCTs) comparing postoperative morbidity in adult patients (i.e., over the age of 18) receiving a VLED with liquid formulation to those receiving a non-VLED control prior to elective bariatric surgery. Outcomes included overall 30-day postoperative morbidity and preoperative weight loss. An inverse variance meta-analysis was performed with GRADE assessment of the quality of evidence.

Results

After reviewing 2,525 citations, four RCTs with 294 patients receiving preoperative VLEDs with liquid formulation and 294 patients receiving a non-VLED control met inclusion. Patients receiving VLED experienced significantly more preoperative weight loss than patients receiving control (mean difference (MD) 3.38 kg, 95% confidence interval (CI) 1.06-5.70, p = 0.004, I² = 95%). According to low certainty evidence, there was a non-significant reduction in 30-day postoperative morbidity in patients receiving VLED prior to bariatric surgery (risk ratio (RR) 0.67, 95%CI 0.39-1.17, p = 0.16, I² = 0%).

Conclusion

The impact of preoperative VLEDs on postoperative outcomes following bariatric surgery remains unclear. It is possible that VLEDs may contribute to decreased postoperative morbidity, but further larger prospective trials are required to investigate the signal identified in this study.

Clinical Impact of Enteral Protein Nutritional Therapy on Patients with Obesity Scheduled for Bariatric Surgery: A Focus on Safety, Efficacy, and Pathophysiological Changes

BACKGROUND

Ketogenic diet-induced weight loss before bariatric surgery (BS) has beneficial effects on the reduction in the liver volume, metabolic profile, and intra- and post-operative complications. However, these beneficial effects can be limited by poor dietary adherence. A potential solution in patients showing a poor adherence in following the prescribed diet could be represented by enteral nutrition strategies. To date, no studies describe the protocol to use for the efficacy and the safety of pre-operative enteral ketogenic nutrition-based dietary protocols in terms of weight reduction, metabolic efficacy, and safety in patients with obesity scheduled for BS.

AIMS AND SCOPE

To assess the clinical impact, efficacy, and safety of ketogenic nutrition enteral protein (NEP) vs. nutritional enteral hypocaloric (NEI) protocols on patients with obesity candidate to BS.

PATIENTS AND METHODS

31 NEP were compared to 29 NEI patients through a 1:1 randomization. The body weight (BW), body mass index (BMI), waist circumference (WC), hip circumference (HC), and neck circumference (NC) were assessed at the baseline and at the 4-week follow-up. Furthermore, clinical parameters were assessed by blood tests, and patients were asked daily to report any side effects, using a self-administered questionnaire.

RESULTS

Compared to the baseline, the BW, BMI, WC, HC, and NC were significantly reduced in both groups studied (p < 0.001). However, we did not find any significative difference between the NEP and NEI groups in terms of weight loss (p = 0.559), BMI (p= 0.383), WC (p = 0.779), and HC (p = 0.559), while a statistically significant difference was found in terms of the NC (NEP, -7.1% vs. NEI, -4%, p = 0.011). Furthermore, we found a significant amelioration of the general clinical status in both groups. However, a statistically significant difference was found in terms of glycemia (NEP, -16% vs. NEI, -8.5%, p < 0.001), insulin (NEP, -49.6% vs. NEI, -17.8%, p < 0.0028), HOMA index (NEP, -57.7% vs. NEI, -24.9%, p < 0.001), total cholesterol (NEP, -24.3% vs. NEI, -2.8%, p < 0.001), low-density lipoprotein (NEP, -30.9% vs. NEI, 1.96%, p < 0.001), apolipoprotein A1 (NEP, -24.2% vs. NEI, -7%, p < 0.001), and apolipoprotein B (NEP, -23.1% vs. NEI, -2.3%, p < 0.001), whereas we did not find any significative difference between the NEP and NEI groups in terms of aortomesenteric fat thickness (p = 0.332), triglyceride levels (p = 0.534), degree of steatosis (p = 0.616), and left hepatic lobe volume (p = 0.264). Furthermore, the NEP and NEI treatments were well tolerated, and no major side effects were registered.

CONCLUSIONS

Enteral feeding is an effective and safe treatment before BS, with NEP leading to better clinical results than NEI on the glycemic and lipid profiles. Further and larger randomized clinical trials are needed to confirm these preliminary data.

The effect of the ketogenic diet on Acne: Could it be a therapeutic tool?

Acne is a chronic inflammatory disease of the pilosebaceous unit resulting from androgen-induced increased sebum production, altered keratinization, inflammation, and bacterial colonization of the hair follicles of the face, neck, chest and back by Propionibacterium acnes. Overall, inflammation and immune responses are strongly implicated in the pathogenesis of acne. Although early colonization with Propionibacterium acnes and family history may play an important role in the disease, it remains unclear exactly what triggers acne and how treatment affects disease progression. The influence of diet on acne disease is a growing research topic, yet few studies have examined the effects of diet on the development and clinical severity of acne disease, and the results have often been contradictory. Interestingly, very low-calorie ketogenic diet (VLCKD) has been associated with both significant reductions in body weight and inflammatory status through the production of ketone bodies and thus it has been expected to reduce the exacerbation of clinical manifestations or even block the trigger of acne disease. Given the paucity of studies regarding the implementation of VLCKD in the management of acne, this review aims to provide evidence from the available scientific literature to support the speculative use of VLCKD in the treatment of acne.

Intensive Weight-Loss Lifestyle Intervention Using Mediterranean Diet and COVID-19 Risk in Older Adults: Secondary Analysis of PREDIMED-Plus Trial

OBJECTIVES

We tested the effects of a weight-loss intervention encouraging energy-reduced MedDiet and physical activity (PA) in comparison to ad libitum MedDiet on COVID-19 incidence in older adults.

DESIGN

Secondary analysis of PREDIMED-Plus, a prospective, ongoing, multicentre randomized controlled trial.

SETTING

Community-dwelling, free-living participants in PREDIMED-Plus trial.

PARTICIPANTS

6,874 Spanish older adults (55-75 years, 49% women) with overweight/obesity and metabolic syndrome.

INTERVENTION

Participants were randomised to Intervention (IG) or Control (CG) Group. IG received intensive behavioural intervention for weight loss with an energy-reduced MedDiet intervention and PA promotion. CG was encouraged to consume ad libitum MedDiet without PA recommendations.

MEASUREMENTS

COVID-19 was ascertained by an independent Event Committee until December 31, 2021. COX regression models compared the effect of PREDIMED-Plus interventions on COVID-19 risk.

RESULTS

Overall, 653 COVID-19 incident cases were documented (IG:317; CG:336) over a median (IQR) follow-up of 5.8 (1.3) years (inclusive of 4.0 (1.2) years before community transmission of COVID-19) in both groups. A significantly lowered risk of COVID-19 incidence was not evident in IG, compared to CG (fully-adjusted HR (95% CI): 0.96 (0.81,1.12)).

CONCLUSIONS

There was no evidence to show that an intensive weight-loss intervention encouraging energy-reduced MedDiet and PA significantly lowered COVID-19 risk in older adults with overweight/obesity and metabolic syndrome in comparison to ad libitum MedDiet. Recommendations to improve adherence to MedDiet provided with or without lifestyle modification suggestions for weight loss may have similar effects in protecting against COVID-19 risk in older adults with high cardiovascular risks.

Immune Modulatory Effects of Ketogenic Diet in Different Disease Conditions

Interceding nutrients have been acquiring increased attention and prominence in the field of healing and deterrence of various disorders. In this light, the present article encompasses several facets of ketogenic diet as an immunomodulator with respect to its expansive clinical applications. Accordingly, several scientific records, models, and case histories, including viral infections, cancer, chronic diseases, e.g., cardiovascular diseases, epilepsy, as well as numerous other neuro-disorders, are assembled, revealing a profound influence of KD in favor of improvement in the patient’s condition. We accentuate possible manifold mechanisms of KD that require further exploration.

Immunmodulatorische Eigenschaften gewichtsreduzierender Maßnahmen evaluiert

Nach dem Rauchen gilt Adipositas mittlerweile als wichtigster beeinflussbarer Risikofaktor für Krebs. Hieran beteiligt sind Entzündungsprozesse sowie oxidativer Stress. P. M. Lorenzo et al. haben nun am Beispiel von adipösen Personen untersucht, inwieweit unterschiedliche Maßnahmen zur Erreichung einer Ernährungsketose bzw. eines Gewichtsverlustes das inflammatorische und oxidative Stressprofil beeinflussen.

Effects of an exogenous ketone ester using multi-omics in skeletal muscle of aging C57BL/6J male mice

Exogenous ketone ester supplementation provides a means to increase circulating ketone concentrations without the dietary challenges imposed by ketogenic diets. Our group has shown that oral R,S-1,3, butanediol diacetoacetate (BD-AcAc2) consumption results in body weight loss or maintenance with moderate increases in circulating ketones. We have previously shown a diet consisting of 25% BD-AcAc2 can maintain lean body mass (LBM) and induce fat mass (FM) loss in young, healthy male mice, but the underlying mechanisms are still unknown. Therefore, the purpose of this study was to determine if a diet consisting of 25% BD-AcAc2 (ketone ester, KE) would alter body composition, transcriptional regulation, the proteome, and the lipidome of skeletal muscle in aged mice. We hypothesized that the KE group would remain weight stable with improvements in body composition compared to controls, resulting in a healthy aging phenotype. Male C57BL/6J mice (n = 16) were purchased from Jackson Laboratories at 72 weeks of age. After 1 week of acclimation, mice were weighed and randomly assigned to one of two groups (n = 8 per group): control (CON) or KE. A significant group by time interaction was observed for body weight (P &lt; 0.001), with KE fed mice weighing significantly less than CON. FM increased over time in the control group but was unchanged in the KE group. Furthermore, LBM was not different between CON and KE mice despite KE mice weighing less than CON mice. Transcriptional analysis of skeletal muscle identified 6 genes that were significantly higher and 21 genes that were significantly lower in the KE group compared to CON. Lipidomic analysis of skeletal muscle identified no differences between groups for any lipid species, except for fatty acyl chains in triacylglycerol which was 46% lower in the KE group. Proteomics analysis identified 44 proteins that were different between groups, of which 11 were lower and 33 were higher in the KE group compared to CON. In conclusion, 72-week-old male mice consuming the exogenous KE, BD-AcAc2, had lower age-related gains in body weight and FM compared to CON mice. Furthermore, transcriptional and proteomics data suggest a signature in skeletal muscle of KE-treated mice consistent with markers of improved skeletal muscle regeneration, improved electron transport chain utilization, and increased insulin sensitivity.

Bibliometric and visual analysis in the field of ketogenic diet on cancer from 2012 to 2021

Increasing evidence demonstrated that the ketogenic diet (KD) played a positive effect on cancer treatment. However, no systematic review and bibliometric analysis were conducted in this field. This study aimed to explore the current status, and reveal the potential trends and hotspots to provide a reference for future research. Publications were extracted from the Web of Science Core Collection. CiteSpace (5.6.R3) software and the website of bibliometrics were used for visual analysis. A total of 500 publications with 334 articles and 166 reviews were included, with the timespan of 2012 to 2021. The United States was the most productive country. Majority of the top 10 institutions were from the United States, and Harvard University was the top-contributing institution. The most prolific author and the co-cited author was Thomas N Seyfried from Boston College. The highest cited reference was published in PLoS ONE, authored by Abdelwahab Mohammed G, with 161 citations. Glioma and breast cancer were the most common types of cancer in this field, while hepatocellular carcinoma and pancreatic cancer were the new hotspots. The anti-tumor mechanism of KD mainly focused on regulating metabolism, decanoic acid, oxidative stress, fatty acid oxidation, and cell apoptosis. Additionally, the presence of "chemotherapy" and "radiotherapy" in the keywords indicated that KD combined with anti-tumor research was a topic, while "immunotherapy" has became a recent frontiers. Notably, as a metabolic therapy, KD was deserved more attention in the treatment of hepatocellular carcinoma and pancreatic cancer, and KD combined with immunotherapy was the new hotspot and frontier. Additionally, more molecular studies and high-quality uniformly, randomized, controlled clinical trials are urgently warranted to evaluate the effect of KD in multiple cancers.

Ketogenic diet administration to mice after a high-fat-diet regimen promotes weight loss, glycemic normalization and induces adaptations of ketogenic pathways in liver and kidney

Objective

The ketogenic diet (KD), characterized by very limited dietary carbohydrate intake and used as nutritional treatment for GLUT1-deficiency syndromes and pharmacologically refractory epilepsy, may promote weight loss and improve metabolic fitness, potentially alleviating the symptoms of osteoarthritis. Here, we have studied the effects of administration of a ketogenic diet in mice previously rendered obese by feeding a high fat diet (HFD) and submitted to surgical destabilization of the medial meniscus to mimic osteoarthritis.

Methods

6-weeks old mice were fed an HFD for 10 weeks and then switched to a chow diet (CD), KD or maintained on a HFD for 8 weeks. Glycemia, β-hydroxybutyrate (BHB), body weight and fat mass were compared among groups. In liver and kidney, protein expression and histone post-translational modifications were assessed by Western blot, and gene expression by quantitative Real-Time PCR.

Results

After a 10 weeks HDF feeding, administration for 8 weeks of a KD or CD induced a comparable weight loss and decrease in fat mass, with better glycemic normalization in the KD group. Histone β-hydroxybutyrylation, but not histone acetylation, was increased in the liver and kidney of mice fed the KD and the rate-limiting ketogenic enzyme HMGCS2 was upregulated – at the gene and protein level – in liver and, to an even greater extent, in kidney. KD-induced HMGCS2 overexpression may be dependent on FGF21, whose gene expression was increased by KD in liver.

Conclusions

Over a period of 8 weeks, KD is more effective than a chow diet to induce metabolic normalization. Besides acting as a fuel molecule, BHB may exert its metabolic effects through modulation of the epigenome - via histone β-hydroxybutyrylation - and extensive transcriptional modulation in liver and kidney.

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In mice fed a high fat diet, the dietary switch to a ketogenic diet causes weight loss and loss of fat mass.

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Glycemic normalization is superior than observed in mice fed a chow diet.

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Ketogenic diet induces mild ketosis, and β-hydroxybutyrylation on histone H3 lysines.

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Upregulation of rate limiting ketogenic protein HMGCS2 is observed in kidney.

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Ketogenic diet may be a transitory nutritional intervention to favor weight loss.