Long-term effects of a ketogenic diet on body composition and bone mineralization in GLUT-1 deficiency syndrome: a case series

Endocrine involvement in hepatic glycogen storage diseases: pathophysiology and implications for care

Hepatic glycogen storage diseases constitute a group of disorders due to defects in the enzymes and transporters involved in glycogen breakdown and synthesis in the liver. Although hypoglycemia and hepatomegaly are the primary manifestations of (most of) hepatic GSDs, involvement of the endocrine system has been reported at multiple levels in individuals with hepatic GSDs. While some endocrine abnormalities (e.g., hypothalamic‑pituitary axis dysfunction in GSD I) can be direct consequence of the genetic defect itself, others (e.g., osteopenia in GSD Ib, insulin-resistance in GSD I and GSD III) may be triggered by the (dietary/medical) treatment. Being aware of the endocrine abnormalities occurring in hepatic GSDs is essential (1) to provide optimized medical care to this group of individuals and (2) to drive research aiming at understanding the disease pathophysiology. In this review, a thorough description of the endocrine manifestations in individuals with hepatic GSDs is presented, including pathophysiological and clinical implications.

Neurodevelopment Is Dependent on Maternal Diet: Placenta and Brain Glucose Transporters GLUT1 and GLUT3

Glucose is the primary energy source for most mammalian cells and its transport is affected by a family of facilitative glucose transporters (GLUTs) encoded by the SLC2 gene. GLUT1 and GLUT3, highly expressed isoforms in the blood-brain barrier and neuronal membranes, respectively, are associated with multiple neurodevelopmental disorders including epilepsy, dyslexia, ADHD, and autism spectrum disorder (ASD). Dietary therapies, such as the ketogenic diet, are widely accepted treatments for patients with the GLUT1 deficiency syndrome, while ameliorating certain symptoms associated with GLUT3 deficiency in animal models. A ketogenic diet, high-fat diet, and calorie/energy restriction during prenatal and postnatal stages can also alter the placental and brain GLUTs expression with long-term consequences on neurobehavior. This review focuses primarily on the role of diet/energy perturbations upon GLUT isoform-mediated emergence of neurodevelopmental and neurodegenerative disorders.

Adherence to ketogenic dietary therapies in epilepsy: A systematic review of literature

Treatment adherence, defined as the degree to which the patient actively follows the plan of care, is very difficult for subjects undergoing ketogenic dietary therapies (KDTs). This is a relevant issue because adherence to dietary therapies is considered 1 of the primary determinants of the treatment's success. This paper aimed to review the literature evidence about KDT adherence according to age and diagnosis of patients. Performed based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses method, this systematic review included clinical trials and observational studies. The risk of bias was assessed by the RoB 2.0 Cochrane tool and the quality of evidence according to the Mixed Methods Appraisal Tool system. Twenty-two articles were included, with more than half (n = 12) having average quality (2-3 stars). The studies' heterogeneity in measuring adherence and diagnosis made it difficult to compare results. Mean adherence rates were 71.5%, 66%, and 63.9% for children, adolescents, and adults, respectively. Adherence and compliance rates varied according to the follow-up period (79.7%, 66.7%, and 37.7% at 6, 24, and 36 months, respectively). The most frequent reasons for low adherence were linked to inefficacy in seizure control, adverse effects, food refusal, difficulty in preparing KDT meals or diet restrictiveness, lack of motivation, poor parental compliance, or cost of the diet. To conclude, there is a lack of standardized tools to measure adherence. Several studies highlighted the families' challenges in adhering to KDTs. These factors should be considered when creating strategies and resources on family education.

Long-term personalized high-protein, high-fat diet in pediatric patients with glycogen storage disease type IIIa: Evaluation of myopathy, metabolic control, physical activity, growth, and dietary compliance

Dietary lipid manipulation has recently been proposed for managing glycogen storage disease (GSD) type IIIa. This study aimed to evaluate the myopathic, cardiac, and metabolic status, physical activity, growth, and dietary compliance of a personalized diet high in protein and fat for 24 months. Of 31 patients with type IIIa GSD, 12 met the inclusion criteria. Of these, 10 patients (mean age 11.2 ± 7.4 years) completed the study. Patients were prescribed a personalized high-protein, high-fat diet, comprising 3.0-3.5 g/kg/day of protein and 3.0-4.5 g/kg/day of fat, constituting 18.5%-28% and 70.5%-75.7% of daily energy, respectively. Dietary compliance was ensured and assessed via the regular administration of questionnaires. Our results revealed consistent and significant decreases of 22%, 54%, and 30% in the creatinine kinase, creatine kinase-myocardial band, and lactate dehydrogenase levels, respectively. Echocardiography revealed improvements in the Z-scores of the left ventricular mass and interventricular septum thickness. A significant increase in body muscle mass was observed, and a higher score was achieved using the Daily Activity Questionnaire. Growth monitoring revealed an arrest in the height-SDS at the 6th and 12th months, followed by subsequent improvement at the end of the second year. A gradual and persistent decline in the periods of hypo- and hyperglycemia has been reported. Biotinidase activity decreased, whereas hepatosteatosis increased and then decreased by the end of the study. Implementing a high-protein, high-fat diet and monitoring key parameters in patients with type IIIa GSD can lead to myopathic and cardiac improvements and increased physical activity.

The effects of popular diets on bone health in the past decade: a narrative review

Bone health encompasses not only bone mineral density but also bone architecture and mechanical properties that can impact bone strength. While specific dietary interventions have been proposed to treat various diseases such as obesity and diabetes, their effects on bone health remain unclear. The aim of this review is to examine literature published in the past decade, summarize the effects of currently popular diets on bone health, elucidate underlying mechanisms, and provide solutions to neutralize the side effects. The diets discussed in this review include a ketogenic diet (KD), a Mediterranean diet (MD), caloric restriction (CR), a high-protein diet (HP), and intermittent fasting (IF). Although detrimental effects on bone health have been noticed in the KD and CR diets, it is still controversial, while the MD and HP diets have shown protective effects, and the effects of IF diets are still uncertain. The mechanism of these effects and the attenuation methods have gained attention and have been discussed in recent years: the KD diet interrupts energy balance and calcium metabolism, which reduces bone quality. Ginsenoside-Rb2, metformin, and simvastatin have been shown to attenuate bone loss during KD. The CR diet influences energy imbalance, glucocorticoid levels, and adipose tissue, causing bone loss. Adequate vitamin D and calcium supplementation and exercise training can attenuate these effects. The olive oil in the MD may be an effective component that protects bone health. HP diets also have components that protect bone health, but their mechanism requires further investigation. In IF, animal studies have shown detrimental effects on bone health, while human studies have not. Therefore, the effects of diets on bone health vary accordingly.

The impact of ketogenic diet on some metabolic and non-metabolic diseases: Evidence from human and animal model experiments

The ketogenic diet (KD) is recognized as minimum carbohydrate and maximum fat intakes, which leads to ketosis stimulation, a state that is thought to metabolize fat more than carbohydrates for energy supply. KD has gained more interest in recent years and is for many purposes, including weight loss and managing serious diseases like type 2 diabetes. On the other hand, many believe that KD has safety issues and are uncertain about the health drawbacks. Thus, the outcomes of the effect of KD on metabolic and non-metabolic disease remain disputable. The current narrative review aims to evaluate the effect of KD on several diseases concerning the human health. To our best knowledge, the first report aims to investigate the efficacy of KD on multiple human health issues including type 2 diabetes and weight loss, cardiovascular disease, kidney failure and hypertension, non-alcoholic fatty liver, mental problem, oral health, libido, and osteoporosis. The literature searches were performed in Databases, PubMed, Scopus, and web of Science looking for both animal and human model designs. The results heterogeneity seems to be explained by differences in diet composition and duration. Also, the available findings may show that proper control of carbohydrates, a significant reduction in glycemic control and glycated hemoglobin, and weight loss by KD can be an approach to improve diabetes and obesity, hypertension, non-alcoholic fatty liver, PCOS, libido, oral health, and mental problem if isocaloric is considered. However, for some other diseases like cardiovascular disease and osteoporosis, more robust data are needed. Therefore, there is robust data to support the notion that KD can be effective for some metabolic and non-metabolic diseases but not for all of them. So they have to be followed cautiously and under the supervision of health professionals.

Long-term follow-up of nutritional status in children with GLUT1 Deficiency Syndrome treated with classic ketogenic diet: a 5-year prospective study

Introduction

The classic ketogenic diet (cKD) is an isocaloric, high fat, low-carbohydrate diet that induces the production of ketone bodies. High consumption of dietary fatty acids, particularly long-chain saturated fatty acids, could impair nutritional status and increase cardiovascular risk. The purpose of this study was to evaluate the long-term effects of a 5-year cKD on body composition, resting energy expenditure, and biochemical parameters in children affected by Glucose Transporter 1 Deficiency Syndrome (GLUT1DS).

Methods

This was a prospective, multicenter, 5-year longitudinal study of children with GLUT1DS treated with a cKD. The primary outcome was to assess the change in nutritional status compared with pre-intervention, considering anthropometric measurements, body composition, resting energy expenditure, and biochemical parameters such as glucose and lipid profiles, liver enzymes, uric acid, creatinine, and ketonemia. Assessments were conducted at pre-intervention and every 12 months of cKD interventions.

Results

Ketone bodies increased significantly in children and adolescents, and remained stable at 5 years, depending on the diet. No significant differences were reported in anthropometric and body composition standards, as well as in resting energy expenditure and biochemical parameters. Bone mineral density increased significantly over time according to increasing age. Body fat percentage significantly and gradually decreased in line with the increase in body weight and the consequent growth in lean mass. As expected, we observed a negative trend in respiratory quotient, while fasting insulin and insulin resistance were found to decrease significantly after cKD initiation.

Conclusion

Long-term adherence to cKD showed a good safety profile on anthropometric measurements, body composition, resting energy expenditure, and biochemical parameters, and we found no evidence of potential adverse effects on the nutritional status of children and adolescents.

The Effect of the Ketogenic Diet on the Therapy of Neurodegenerative Diseases and Its Impact on Improving Cognitive Functions

The ketogenic diet (KD) is a high-fat and low-carbohydrate diet with controlled amounts of protein. The use of drastic caloric restriction or ultralow-carbohydrate diets increases the production of ketone bodies, which are an alternative energy substrate in situations of insufficient glucose supply. Alzheimer's disease (AD) and Parkinson's disease are the most common neurodegenerative diseases in the world. It is believed that carbohydrate metabolism disorders may affect the progression of these diseases, as confirmed by both animal and human studies. Among patients with AD, the presence of ketone bodies in the body can improve cerebral circulation. Among Parkinson's patients, the presence of ketone bodies can reduce muscle tremor and stiffness, as well as improve cognitive function. The results of the research indicate that using a low-carbohydrate diet, including a KD, may have a beneficial effect on brain function in diseases that cause neuronal damage.

Research Involvement in a Group of Registered Dietitian Nutritionists Specializing in Ketogenic Diet Therapies for Epilepsy

BACKGROUND

There is a growing need for studies on ketogenic diet (KD) therapies. Registered dietitian nutritionists (RDNs) should lead efforts to better understand nutritional risks and benefits of the KD to inform evidence-based practices.

OBJECTIVE

The purpose of this study was to explore participation in research amongst RDNs practicing in KD therapies for epilepsy and identify barriers to participation.

DESIGN

This cross-sectional study collected professional experience, research involvement and output, and perceived barriers to conducting research.

PARTICIPANTS/SETTING

This study surveyed 66 RDNs practicing in KD therapies for epilepsy.

MAIN OUTCOME MEASURE

Research involvement was assessed using the Dietitian Research Involvement Survey (DRIS) score. Research output was reported as type and number of publications. Barriers to research included lack of time, resources, administrative support, training, and/or skill.

STATISTICAL ANALYSES

Data were summarized using descriptive statistics such as means and standard deviations, medians and interquartile ranges, counts and percentages, as appropriate.

RESULTS

The median DRIS score was 31 out of 60 (range: 16-60). Thirty-two participants (48.5%) reported publishing or presenting data, and only 13.6% published a manuscript on ketogenic diet therapies as a leading author. The main barriers to participating in research were insufficient time (83.3%), insufficient funding (81.8%), and priority of work (70.8%). Research involvement scores were not affected by lack of time and resources, however scores were lower in RDNs reporting lack of interest, training, and skill in research.

CONCLUSIONS

While ketogenic RDNs participated in research, most were not leading projects or publications. To increase research involvement amongst RDNs, focus should include overcoming structural barriers while facilitating knowledge acquisition for those lower on the research continuum.

Substantial early changes in bone and calcium metabolism among adult pharmacoresistant epilepsy patients on a modified Atkins diet

Objective

The aim of this study was to investigate whether the modified Atkins diet (MAD), a variant of the ketogenic diet, has an impact on bone‐ and calcium (Ca) metabolism.

Methods

Two groups of adult patients with pharmacoresistant epilepsy were investigated. One, the diet group (n = 53), was treated with MAD for 12 weeks, whereas the other, the reference group (n = 28), stayed on their habitual diet in the same period. All measurements were performed before and after the 12 weeks in both groups. We assessed bone health by measuring parathyroid hormone (PTH), Ca, 25‐OH vitamin D (25‐OH vit D), 1,25‐OH vitamin D (1,25‐OH vit D), phosphate, alkaline phosphatase (ALP), and the bone turnover markers procollagen type 1 N‐terminal propeptide (P1NP) and C‐terminal telopeptide collagen type 1 (CTX‐1). In addition, we examined the changes of sex hormones (estradiol, testosterone, luteinizing hormone, follicle‐stimulating hormone), sex hormone‐binding globulin, and leptin.

Results

After 12 weeks of MAD, we found a significant reduction in PTH, Ca, CTX‐1, P1NP, 1,25‐OH vit D, and leptin. There was a significant increase in 25‐OH vit D. These changes were most pronounced among patients <37 years old, and in those patients with the highest body mass index (≥25.8 kg/m²), whereas sex and type of antiseizure medication had no impact on the results. For the reference group, the changes were nonsignificant for all the analyses. In addition, the changes in sex hormones were nonsignificant.

Significance

Twelve weeks of MAD treatment leads to significant changes in bone and Ca metabolism, with a possible negative effect on bone health as a result. A reduced level of leptin may be a triggering mechanism. The changes could be important for patients on MAD, and especially relevant for those patients who receive treatment with MAD at an early age before peak bone mass is reached.

International Recommendations for the Management of Adults Treated With Ketogenic Diet Therapies

OBJECTIVE

To evaluate current clinical practices and evidence-based literature to establish preliminary recommendations for the management of adults using ketogenic diet therapies (KDTs).

METHODS

A 12-topic survey was distributed to international experts on KDTs in adults consisting of neurologists and dietitians at medical institutions providing KDTs to adults with epilepsy and other neurologic disorders. Panel survey responses were tabulated by the authors to determine the common and disparate practices between institutions and to compare these practices in adults with KDT recommendations in children and the medical literature. Recommendations are based on a combination of clinical evidence and expert opinion regarding management of KDTs.

RESULTS

Surveys were obtained from 20 medical institutions with >2,000 adult patients treated with KDTs for epilepsy or other neurologic disorders. Common side effects reported are similar to those observed in children, and recommendations for management are comparable with important distinctions, which are emphasized. Institutions differ with regard to recommended biochemical assessment, screening, monitoring, and concern for long-term side effects, and further investigation is warranted to determine the optimal clinical management. Differences also exist between screening and monitoring practices among adult and pediatric providers.

CONCLUSIONS

KDTs may be safe and effective in treating adults with drug-resistant epilepsy, and there is emerging evidence supporting the use in other adult neurologic disorders and general medical conditions as well. Therefore, expert recommendations to guide optimal care are critical as well as further evidence-based investigation.

Incidence and Characteristics of Kidney Stones in Patients on Ketogenic Diet: A Systematic Review and Meta-Analysis

Very-low-carbohydrate diets or ketogenic diets are frequently used for weight loss in adults and as a therapy for epilepsy in children. The incidence and characteristics of kidney stones in patients on ketogenic diets are not well studied. Methods: A systematic literature search was performed, using MEDLINE, EMBASE, and Cochrane Database of Systematic Reviews from the databases’ inception through April 2020. Observational studies or clinical trials that provide data on the incidence and/or types of kidney stones in patients on ketogenic diets were included. We applied a random-effects model to estimate the incidence of kidney stones. Results: A total of 36 studies with 2795 patients on ketogenic diets were enrolled. The estimated pooled incidence of kidney stones was 5.9% (95% CI, 4.6–7.6%, I2 = 47%) in patients on ketogenic diets at a mean follow-up time of 3.7 +/− 2.9 years. Subgroup analyses demonstrated the estimated pooled incidence of kidney stones of 5.8% (95% CI, 4.4–7.5%, I2 = 49%) in children and 7.9% (95% CI, 2.8–20.1%, I2 = 29%) in adults, respectively. Within reported studies, 48.7% (95% CI, 33.2–64.6%) of kidney stones were uric stones, 36.5% (95% CI, 10.6–73.6%) were calcium-based (CaOx/CaP) stones, and 27.8% (95% CI, 12.1–51.9%) were mixed uric acid and calcium-based stones, respectively. Conclusions: The estimated incidence of kidney stones in patients on ketogenic diets is 5.9%. Its incidence is approximately 5.8% in children and 7.9% in adults. Uric acid stones are the most prevalent kidney stones in patients on ketogenic diets followed by calcium-based stones. These findings may impact the prevention and clinical management of kidney stones in patients on ketogenic diets.

Effects of a low-carbohydrate ketogenic diet on health parameters in resistance-trained women

PURPOSE

The aim of this study was to evaluate the effect of a ketogenic diet on blood pressure, visceral adipose tissue (VAT), bone mineral content (BMC), and bone mineral density (BMD) in trained women.

METHODS

Twenty-one resistance-trained women performed an 8-week resistance training program after a 3-week familiarization phase. Participants were randomly assigned to a non-ketogenic diet (n = 11, NKD) or ketogenic diet (n = 10, KD) group. Health parameters were measured before and after the nutritional intervention. Blood pressure was measured using a digital automatic monitor, while VAT, BMC, and BMD changes were measured by dual-energy X-ray absorptiometry.

RESULTS

There was a significant reduction in systolic blood pressure in KD (mean ± SD [IC 95%], P value, Hedges' g; - 6.3 ± 6.0 [- 10.5, - 2.0] mmHg, P = 0.009, g = - 0.81) but not in NKD (- 0.4 ± 8.9 [- 6.8, 6.0] mmHg, P = 0.890, g = - 0.04). The results on VAT showed no changes in both groups. The KD showed a small favorable effect on BMD (0.02 ± 0.02 [0.01, 0.03] g·cm^-2, P = 0.014, g = 0.19) while NKD did not show significant changes (0.00 ± 0.02 [- 0.02, 0.02] g·cm^-2, P = 0.886, g = 0.01). No differences in group or in the time × group interaction were found in any of the variables.

CONCLUSIONS

Consuming a low-carbohydrate high-fat KD in conjunction with a resistance training program might help to promote the improvement of health-related markers in resistance-trained women. Long-term studies are required to evaluate the superiority of a KD in comparison to a traditional diet.

Energy Metabolism and Ketogenic Diets: What about the Skeletal Health? A Narrative Review and a Prospective Vision for Planning Clinical Trials on this Issue

The existence of a common mesenchymal cell progenitor shared by bone, skeletal muscle, and adipocytes cell progenitors, makes the role of the skeleton in energy metabolism no longer surprising. Thus, bone fragility could also be seen as a consequence of a “poor” quality in nutrition. Ketogenic diet was originally proven to be effective in epilepsy, and long-term follow-up studies on epileptic children undergoing a ketogenic diet reported an increased incidence of bone fractures and decreased bone mineral density. However, the causes of such negative impacts on bone health have to be better defined. In these subjects, the concomitant use of antiepileptic drugs and the reduced mobilization may partly explain the negative effects on bone health, but little is known about the effects of diet itself, and/or generic alterations in vitamin D and/or impaired growth factor production. Despite these remarks, clinical studies were adequately designed to investigate bone health are scarce and bone health related aspects are not included among the various metabolic pathologies positively influenced by ketogenic diets. Here, we provide not only a narrative review on this issue, but also practical advice to design and implement clinical studies on ketogenic nutritional regimens and bone health outcomes. Perspectives on ketogenic regimens, microbiota, microRNAs, and bone health are also included.

A unifying mechanism of ketogenic diet action: The multiple roles of nicotinamide adenine dinucleotide

The ability of a ketogenic diet to treat seizures and render a neuronal network more resistant to strong electrical activity has been observed for a century in clinics and for decades in research laboratories. Alongside ongoing efforts to understand how this therapy works to stop seizures, metabolic health is increasingly appreciated as critical buffer to resisting and recovering from acute and chronic disease. Accordingly, links between metabolism and health, and the broader emerging impact of the ketogenic diet in improving diverse metabolic, immunological and neurological conditions, have served to intensify the search for its key and/or common mechanisms. Here we review diverse evidence for increased levels of NAD⁺, and thus an altered ratio of NAD⁺/NADH, during metabolic therapy with a ketogenic diet. We propose this as a potential unifying mechanism, and highlight some of the evidence linking altered NAD⁺/NADH with reduced seizures and with a range of short and long-term changes associated with the beneficial effects of a ketogenic diet. An increase in NAD⁺/NADH is consistent with multiple lines of evidence and hypotheses, and therefore we suggest that increased NAD⁺ may be a common mechanism underlying beneficial effects of ketogenic diet therapy.

The ketogenic diet all grown up-Ketogenic diet therapies for adults

The use of ketogenic diet therapies (KDT) in adults has expanded in the last two decades and has been accompanied by a surge of new retrospective as well as prospective studies evaluating its efficacy in adults with epilepsy. In this review article, we will highlight the recent clinical trials and advances in the use of the ketogenic diet therapy (KDT) in adult patients with epilepsy. We will analyze the responder rate in regard to the epilepsy syndrome (focal vs generalized) to identify adults who are optimal to consider for KDT. In addition to its role in treating patients with chronic epilepsy, we will explore the emerging use of the KDT in the critical care setting in adults with refractory and super-refractory status epilepticus as well as other neurologic disorders. Finally, we will discuss special considerations for the use of KDT in adults with epilepsy including its potential long-term effects on bone and cardiovascular health, and its use in pregnancy.

Confusion in the nomenclature of ketogenic diets blurs evidence

Ketogenic diets have been proposed as a non-pharmacological strategy for the management of several chronic conditions. Their efficacy and safety have been evaluated in the field of neurology, oncology and endocrinology for disorders including cancer, dementia, drug-resistant epilepsy, migraines, obesity, polycystic ovary syndrome and type 2 diabetes mellitus. The nutritional requirements of these subjects are expected to differ significantly. Indeed, although all ketogenic diets restrict carbohydrates, each intervention is characterized by a specific daily calorie intake, macronutrient composition and duration. However, the adopted nomenclature was often unclear to the general reader; also, the same abbreviations for different protocols were used. This possibly resulted in mistakes in the interpretation of the available evidence and limited the impact of studies on the topic in the clinical practice. Adopting a clear and consistent vocabulary is key in any context. Here, we present a practical and clinically-based proposal for the classification and abbreviation of ketogenic diets.

Effects of a ketogenic diet in overweight women with polycystic ovary syndrome

Background

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in women during reproductive age. It is characterised clinically by oligo-ovulation or anovulation, hyper-androgenism, and the presence of polycystic ovaries. It is associated with an increased prevalence of metabolic syndrome, cardiovascular disease and type 2 diabetes. The onset of PCOS has been associated to several hereditary and environmental factors, but insulin resistance plays a key pathogenetic role. We sought to investigate the effects of a ketogenic diet (KD) on women of childbearing age with a diagnosis of PCOS.

Methods

Fourteen overweight women with diagnosis of PCOS underwent to a ketogenic Mediterranean diet with phyoextracts (KEMEPHY) for 12 week. Changes in body weight, body mass index (BMI), fat body mass (FBM), lean body mass (LBM), visceral adipose tissue (VAT), insulin, glucose, HOMA-IR, total cholesterol, low density lipoprotein (LDL), high density lipoprotein (HDL), triglycerides (TGs), total and free testosterone, luteinizing hormone (LH), follicle stimulating hormone (FSH); dehydroepiandrosterone sulfate (DHEAs), estradiol, progesterone, sex hormone binding globulin (SHBG) and Ferriman Gallwey score were evaluated.

Results

After 12 weeks, anthropometric and body composition measurements revealed a significant reduction of body weight (− 9.43 kg), BMI (− 3.35), FBM (8.29 kg) and VAT. There was a significant, slightly decrease of LBM. A significant decrease in glucose and insulin blood levels were observed, together with a significant improvement of HOMA-IR. A significant decrease of triglycerides, total cholesterol and LDL were observed along with a rise in HDL levels. The LH/FSH ratio, LH total and free testosterone, and DHEAS blood levels were also significantly reduced. Estradiol, progesterone and SHBG increased. The Ferriman Gallwey Score was slightly, although not significantly, reduced.

Conclusions

Our results suggest that a KD may be considered as a valuable non pharmacological treatment for PCOS. Longer treatment periods should be tested to verify the effect of a KD on the dermatological aspects of PCOS.

Trial registration Clinicaltrial.gov, NCT04163120, registrered 10 November 2019, retrospectively registered, https://clinicaltrials.gov.

The effect of chronic neuroglycopenia on resting state networks in GLUT1 syndrome across the lifespan

Glucose transporter type I deficiency syndrome (GLUT1DS) is an encephalopathic disorder due to a chronic insufficient transport of glucose into the brain. PET studies in GLUT1DS documented a widespread cortico‐thalamic hypometabolism and a signal increase in the basal ganglia, regardless of age and clinical phenotype. Herein, we captured the pattern of functional connectivity of distinct striatal, cortical, and cerebellar regions in GLUT1DS (10 children, eight adults) and in healthy controls (HC, 19 children, 17 adults) during rest. Additionally, we explored for regional connectivity differences in GLUT1 children versus adults and according to the clinical presentation. Compared to HC, GLUT1DS exhibited increase connectivity within the basal ganglia circuitries and between the striatal regions with the frontal cortex and cerebellum. The excessive connectivity was predominant in patients with movement disorders and in children compared to adults, suggesting a correlation with the clinical phenotype and age at fMRI study. Our findings highlight the primary role of the striatum in the GLUT1DS pathophysiology and confirm the dependency of symptoms to the patients' chronological age. Despite the reduced chronic glucose uptake, GLUT1DS exhibit increased connectivity changes in regions highly sensible to glycopenia. Our results may portrait the effect of neuroprotective brain strategy to overcome the chronic poor energy supply during vulnerable ages.

Very-low-calorie ketogenic diet (VLCKD) in the management of metabolic diseases: systematic review and consensus statement from the Italian Society of Endocrinology (SIE)

BACKGROUND

Weight loss is a milestone in the prevention of chronic diseases associated with high morbility and mortality in industrialized countries. Very-low calorie ketogenic diets (VLCKDs) are increasingly used in clinical practice for weight loss and management of obesity-related comorbidities. Despite evidence on the clinical benefits of VLCKDs is rapidly emerging, some concern still exists about their potential risks and their use in the long-term, due to paucity of clinical studies. Notably, there is an important lack of guidelines on this topic, and the use and implementation of VLCKDs occurs vastly in the absence of clear evidence-based indications.

PURPOSE

We describe here the biochemistry, benefits and risks of VLCKDs, and provide recommendations on the correct use of this therapeutic approach for weight loss and management of metabolic diseases at different stages of life.

Quality of Life in Chronic Ketogenic Diet Treatment: The GLUT1DS Population Perspective

BACKGROUND

Glucose transporter type 1 deficiency syndrome (GLUT1DS) is a rare, genetically determined neurological disorder, for which Ketogenic Diet (KD) represents the gold standard life-long treatment. The aim of this study is to investigate health related quality of life in a well characterized cohort of patients affected by GLUT1DS treated with KD, evaluating factors that can influence patients' and parents' quality of life perception.

METHODS

This is a double center exploratory research study. A postal survey with auto-administrable questionnaires was conducted among 17 subjects (aged 3-22 years) with diagnosis of GLUT1DS, receiving a stable KD treatment for more than 1 year. The Pediatric Quality of Life Inventory (PedsQL) 4.0 Generic Core Scales was adopted. Clinical variables analyzed in relation to quality of life were frequency of epileptic seizures and movement disorder since KD introduction, presence of intellectual disability (ID), and KD ratio.

RESULTS

Quality of life global scores were impaired both in parents' and children's perspectives, with a significant concordance. Taking into consideration subscales, the average was 64.17 (range 10-100) for physical functioning, 74.23 (range 30-100) for emotional functioning, 62.64 (range 10-100) for social functioning, and 56 (range 15-92) for school functioning.

CONCLUSIONS

In patients with GLUT1DS the quality of life perception is comparable to that of other patients with chronic disease. In our sample, the presence of movement disorder seems to be a crucial element in quality of life perception.

Long-Term Effects of a Novel Continuous Remote Care Intervention Including Nutritional Ketosis for the Management of Type 2 Diabetes: A 2-Year Non-randomized Clinical Trial

Purpose: Studies on long-term sustainability of low-carbohydrate approaches to treat diabetes are limited. We previously reported the effectiveness of a novel digitally-monitored continuous care intervention (CCI) including nutritional ketosis in improving weight, glycemic outcomes, lipid, and liver marker changes at 1 year. Here, we assess the effects of the CCI at 2 years. Materials and methods: An open label, non-randomized, controlled study with 262 and 87 participants with T2D were enrolled in the CCI and usual care (UC) groups, respectively. Primary outcomes were retention, glycemic control, and weight changes at 2 years. Secondary outcomes included changes in body composition, liver, cardiovascular, kidney, thyroid and inflammatory markers, diabetes medication use and disease status. Results: Reductions from baseline to 2 years in the CCI group resulting from intent-to-treat analyses included: HbA1c, fasting glucose, fasting insulin, weight, systolic blood pressure, diastolic blood pressure, triglycerides, and liver alanine transaminase, and HDL-C increased. Spine bone mineral density in the CCI group was unchanged. Use of any glycemic control medication (excluding metformin) among CCI participants declined (from 55.7 to 26.8%) including insulin (-62%) and sulfonylureas (-100%). The UC group had no changes in these parameters (except uric acid and anion gap) or diabetes medication use. There was also resolution of diabetes (reversal, 53.5%; remission, 17.6%) in the CCI group but not in UC. All the reported improvements had p < 0.00012. Conclusion: The CCI group sustained long-term beneficial effects on multiple clinical markers of diabetes and cardiometabolic health at 2 years while utilizing less medication. The intervention was also effective in the resolution of diabetes and visceral obesity with no adverse effect on bone health. Clinical Trial Registration: Clinicaltrials.gov NCT02519309.

Bone loss and biomechanical reduction of appendicular and axial bones under ketogenic diet in rats

A ketogenic diet (KD) is composed of low-carbohydrate, high-fat and adequate levels of protein. It has been used for decades as a method to treat pediatric refractory epilepsy. However, recently, its side effects on the bones have received increasing attention. In order to comprehensively evaluate the effect of KD on the microstructures and mechanical properties of the skeleton, 14 male Sprague-Dawley rats were equally divided into two groups and fed with a KD (ratio of fat to carbohydrate and protein, 3:1) or a standard diet for 12 weeks. Body weight, as well as blood ketone and glucose levels, were monitored during the experiment. Bone morphometric analyses via micro-computerized tomography were performed on cortical and trabecular bone at the middle L4 vertebral body, the proximal humerus and tibia. The compressive stiffness and strength of scanned skeletal areas were calculated using micro-finite element analysis. The KD led to higher ketone levels and lower glucose levels, with reduced body weight and total bone mineral density (TBMD). After 12 weeks, the diet reduced the bone volume fraction, the trabecular number of cancellous bone, cortical thickness, total cross-sectional area inside the periosteal envelope and the bone area of cortical bone in the tibia and humerus, while increasing trabecular separation. However, KD may not affect the L4 vertebral body. The serum calcium or phosphate concentrations in the blood remained unchanged. In addition, bone stiffness and strength were clearly decreased by the KD, and significantly correlated with the BMD and bone area at all scanned sites. In conclusion, KD led to significant bone loss and reduced biomechanical function in appendicular bones, with a lesser impact on axial bones.

Ketogenic diet effects on 52 children with pharmacoresistant epileptic encephalopathy: A clinical prospective study

OBJECTIVE

To evaluate the clinical impact of ketogenic diet (KD) on children with pharmacoresistant epileptic encephalopathy.

METHODS

In all, 52 children with pharmacoresistant epileptic encephalopathy that diagnosed in our hospital from July 2012 to June 2015 were selected, including West syndrome 38 cases, Lennox-Gastaut Syndrome 7 cases, Doose Syndrome 1 case, and Dravet syndrome 6 cases, and the effect, compliance, adverse reactions, electroencephalogram (EEG), and cognitive function were analyzed. Modified Johns Hopkins protocol was used to initiate KD, and Engel scale was used to evaluate the effect, and evaluated the effect of KD on the cognition, language, and motor function.

RESULTS

At 12 weeks of KD treatment, the patients achieved I, II, III, and IV grade effect were accounted for 26.9% (14/52 cases), 17.3% (9/52 cases), 11.5% (6/52 cases), and 44.2% (23/52 cases), respectively, according to Engel scale. KD has different effect on different epileptic syndromes, best effect on Doose syndromes of 100%, and better effect on West syndrome with the effect rate of 57.9%, and the total effect number was 22 cases. The reduction of epileptiform discharges in the awake state before KD treatment was correlated with the seizure time after 3 months of KD treatment (r = .330, p = .017). The cognitive function of 23 patients was improved, 12 patients had language improvement, and the motor function was improved in 10 patients. In all, 23 patients had adverse reactions, and all patients were tolerated and improved.

CONCLUSION

KD has certain effect on children with pharmacoresistant epileptic encephalopathy, and it can reduce interictal epileptic discharge frequency, and improve the background rhythm of EEG. The reduction of epileptiform discharges in awake state is in favor of the reduction of seizures frequency, thus increasing the efficacy, and improve the cognitive function, language, and motor function to varying degrees, combined with less adverse reaction, which is worthy of clinical application.

The effect of the ketogenic diet on the developing skeleton

The ketogenic diet (KD) is a medically supervised, high fat, low carbohydrate and restricted protein diet which has been used successfully in patients with refractory epilepsy. Only one published report has explored its effect on the skeleton. We postulated that the KD impairs skeletal health parameters in patients on the KD. Patients commenced on the KD were enrolled in a prospective, longitudinal study, with monitoring of Dual-energy X-ray absorptiometry (DXA) derived bone parameters including bone mineral content and density (BMD). Areal BMD was converted to bone mineral apparent density (BMAD) where possible. Biochemical parameters, including Vitamin D, and bone turnover markers, including osteocalcin, were assessed. Patients were stratified for level of mobility using the gross motor functional classification system (GMFCS). 29 patients were on the KD for a minimum of 6 months (range 0.5-6.5 years, mean 2.1 years). There was a trend towards a reduction in lumbar spine (LS) BMD Z score of 0.1562 (p=0.071) per year and 20 patients (68%) had a lower BMD Z score at the end of treatment. While less mobile patients had lower baseline Z scores, the rate of bone loss on the diet was greater in the more mobile patients (0.28 SD loss per year, p=0.026). Height adjustment of DXA data was possible for 13 patients, with a mean reduction in BMAD Z score of 0.19 SD. Only two patients sustained fractures. Mean urinary calcium-creatinine ratios were elevated (0.77), but only 1 patient developed renal calculi. Children on the KD exhibited differences in skeletal development that may be related to the diet. The changes were independent of height but appear to be exaggerated in patients who are ambulant. Clinicians should be aware of potential skeletal side effects and monitor bone health during KD treatment. Longer term follow up is required to determine adult/peak bone mass and fracture risk throughout life.

Treatment issues for children with epilepsy transitioning to adult care

This is the third of three papers that summarize the second symposium on Transition in Epilepsies held in Paris in June 2016. This paper focuses on treatment issues that arise during the course of childhood epilepsy and make the process of transition to adult care more complicated. Some AEDs used during childhood, such as stiripentol, vigabatrin, and cannabidiol, are unfamiliar to adult epilepsy specialists. In addition, new drugs are being developed for treatment of specific childhood onset epilepsy syndromes and have no indication yet for adults. The ketogenic diet may be effective during childhood but is difficult to continue in adult care. Regional adult epilepsy diet clinics could be helpful. Polytherapy is common for patients transitioning to adult care. Although these complex AED regimes are difficult, they are often possible to simplify. AEDs used in childhood may need to be reconsidered in adulthood. Rescue medications to stop prolonged seizures and clusters of seizures are in wide home use in children and can be continued in adulthood. Adherence/compliance is notoriously difficult for adolescents, but there are simple clinical approaches that should be helpful. Mental health issues including depression and anxiety are not always diagnosed and treated in children and young adults even though effective treatments are available. Attention deficit hyperactivity disorder and aggressive behavior disorders may interfere with transition and successful adulthood but these can be treated. For the majority, the adult social outcome of children with epilepsy is unsatisfactory with few proven interventions. The interface between pediatric and adult care for children with epilepsy is becoming increasingly complicated with a need for more comprehensive transition programs and adult epileptologists who are knowledgeable about special treatments that benefit this group of patients.

The changing face of dietary therapy for epilepsy

Ketogenic diet is an established and effective non-pharmacologic treatment for drug-resistant epilepsy. Ketogenic diet represents the treatment of choice for GLUT-1 deficiency syndrome and pyruvate dehydrogenase complex deficiency. Infantile spasms, Dravet syndrome and myoclonic-astatic epilepsy are epilepsy syndromes for which ketogenic diet should be considered early in the therapeutic pathway. Recently, clinical indications for ketogenic diet have been increasing, as there is emerging evidence regarding safety and effectiveness. Specifically, ketogenic diet response has been investigated in refractory status epilepticus and encephalopathy with status epilepticus during sleep. New targets in neuropharmacology, such as mitochondrial permeability transition, are being studied and might lead to using it effectively in other neurological diseases. But, inefficient connectivity and impaired ketogenic diet proposal limit ideal availability of this therapeutic option. Ketogenic diet in Italy is not yet considered as standard of care, not even as a therapeutic option for many child neurologists and epileptologists.

CONCLUSIONS

The aim of this review is to revisit ketogenic diet effectiveness and safety in order to highlight its importance in drug-resistant epilepsy and other neurological disorders.

WHAT IS KNOWN

• Ketogenic diet efficacy is now described in large case series, with adequate diet compliance and side effects control. • Ketogenic diet is far from being attempted as a first line therapy. Its availability varies worldwide. What is New: • New pharmacological targets such as mitochondrial permeability transition and new epileptic syndromes and etiologies responding to the diet such as refractory status epilepticus are being pointed out. • Ketogenic diet can function at its best when used as a tailor-made therapy. Fine tuning is crucial.

Reduced bone mineral density in glycogen storage disease type III: evidence for a possible connection between metabolic imbalance and bone homeostasis

INTRODUCTION

Glycogen storage disease type III (GSDIII) is an inborn error of carbohydrate metabolism caused by deficient activity of glycogen debranching enzyme (GDE). It is characterized by liver, cardiac muscle and skeletal muscle involvement. The presence of systemic complications such as growth retardation, ovarian polycystosis, diabetes mellitus and osteopenia/osteoporosis has been reported. The pathogenesis of osteopenia/osteoporosis is still unclear.

OBJECTIVES

The aim of the current study was to evaluate the bone mineral density (BMD) in GSDIII patients and the role of metabolic and endocrine factors and physical activity on bone status.

METHODS

Nine GSDIII patients were enrolled (age 2-20years) and compared to eighteen age and sex matched controls. BMD was evaluated by Dual-emission-X-ray absorptiometry (DXA) and Quantitative ultrasound (QUS). Clinical and biochemical parameters of endocrine system function and bone metabolism were analyzed. Serum levels of the metabolic control markers were evaluated. Physical activity was evaluated by administering the International Physical Activity Questionnaire (IPAQ).

RESULTS

GSDIII patients showed reduced BMD detected at both DXA and QUS, decreased serum levels of IGF-1, free IGF-1, insulin, calcitonin, osteocalcin (OC) and increased serum levels of C-terminal cross-linking telopeptide of type I collagen (CTX). IGF-1 serum levels inversely correlated with AST and ALT serum levels. DXA Z-score inversely correlated with cholesterol and triglycerides serum levels and directly correlated with IGF-1/IGFBP3 molar ratio. No difference in physical activity was observed between GSDIII patients and controls.

DISCUSSION

Our data confirm the presence of reduced BMD in GSDIII. On the basis of the results, we hypothesized that metabolic imbalance could be the key factor leading to osteopenia, acting through different mechanisms: chronic hyperlipidemia, reduced IGF-1, Insulin and OC serum levels. Thus, the mechanism of osteopenia/osteoporosis in GSDIII is probably multifactorial and we speculate on the factors involved in its pathogenesis.

Glucose Transporters at the Blood-Brain Barrier: Function, Regulation and Gateways for Drug Delivery

Glucose transporters (GLUTs) at the blood-brain barrier maintain the continuous high glucose and energy demands of the brain. They also act as therapeutic targets and provide routes of entry for drug delivery to the brain and central nervous system for treatment of neurological and neurovascular conditions and brain tumours. This article first describes the distribution, function and regulation of glucose transporters at the blood-brain barrier, the major ones being the sodium-independent facilitative transporters GLUT1 and GLUT3. Other GLUTs and sodium-dependent transporters (SGLTs) have also been identified at lower levels and under various physiological conditions. It then considers the effects on glucose transporter expression and distribution of hypoglycemia and hyperglycemia associated with diabetes and oxygen/glucose deprivation associated with cerebral ischemia. A reduction in glucose transporters at the blood-brain barrier that occurs before the onset of the main pathophysiological changes and symptoms of Alzheimer's disease is a potential causative effect in the vascular hypothesis of the disease. Mutations in glucose transporters, notably those identified in GLUT1 deficiency syndrome, and some recreational drug compounds also alter the expression and/or activity of glucose transporters at the blood-brain barrier. Approaches for drug delivery across the blood-brain barrier include the pro-drug strategy whereby drug molecules are conjugated to glucose transporter substrates or encapsulated in nano-enabled delivery systems (e.g. liposomes, micelles, nanoparticles) that are functionalised to target glucose transporters. Finally, the continuous development of blood-brain barrier in vitro models is important for studying glucose transporter function, effects of disease conditions and interactions with drugs and xenobiotics.

Low-carbohydrate, high-fat diets have sex-specific effects on bone health in rats

PURPOSE

Studies in humans suggest that consumption of low-carbohydrate, high-fat diets (LC-HF) could be detrimental for growth and bone health. In young male rats, LC-HF diets negatively affect bone health by impairing the growth hormone/insulin-like growth factor axis (GH/IGF axis), while the effects in female rats remain unknown. Therefore, we investigated whether sex-specific effects of LC-HF diets on bone health exist.

METHODS

Twelve-week-old male and female Wistar rats were isoenergetically pair-fed either a control diet (CD), "Atkins-style" protein-matched diet (LC-HF-1), or ketogenic low-protein diet (LC-HF-2) for 4 weeks. In females, microcomputed tomography and histomorphometry analyses were performed on the distal femur. Sex hormones were analysed with liquid chromatography-tandem mass spectrometry, and endocrine parameters including GH and IGF-I were measured by immunoassay.

RESULTS

Trabecular bone volume, serum IGF-I and the bone formation marker P1NP were lower in male rats fed both LC-HF diets versus CD. LC-HF diets did not impair bone health in female rats, with no change in trabecular or cortical bone volume nor in serum markers of bone turnover between CD versus both LC-HF diet groups. Pituitary GH secretion was lower in female rats fed LC-HF diet, with no difference in circulating IGF-I. Circulating sex hormone concentrations remained unchanged in male and female rats fed LC-HF diets.

CONCLUSION

A 4-week consumption of LC-HF diets has sex-specific effects on bone health-with no effects in adult female rats yet negative effects in adult male rats. This response seems to be driven by a sex-specific effect of LC-HF diets on the GH/IGF system.

Effects of antiepileptic drugs on bone health and growth potential in children with epilepsy

BACKGROUND

Bone health may be impaired in children with epilepsy.

OBJECTIVES

Our objective was to characterize bone mineral density (BMD) and bone growth in children receiving antiepileptic drugs (AEDs) and to assess the effects of co-morbidity, vitamin D deficiency, and type of drugs used.

DATA SOURCES

Data were sourced from PubMed, Embase, and Web of Science.

ELIGIBILITY CRITERIA

Cross-sectional, cohort, case-control, or randomized controlled trials reporting BMD or parameters of bone growth.

PARTICIPANTS

Children with epilepsy compared with controls.

INTERVENTIONS

AEDS or ketogenic diet.

STUDY APPRAISAL

The studies were evaluated by one author.

SYNTHESIS METHODS

Studies were categorized as reporting reduced BMD or not at any skeletal site as outcome. A logistic regression was performed for age, percent boys, study design, type of AED, co-morbidity or not, and signs of vitamin D deficiency/osteomalacia or not.

RESULTS

Carbamazepine and valproate were analyzed as monotherapy in 11 studies, and for both drugs a limited decrease in BMD seemed present. For oxcarbazepine, levetiracetam, phenytoin, phenobarbital, and topiramate, only one study with monotherapy was found for each drug, none of which reported decreased bone density. Polytherapy with AEDs seemed to be associated with a larger decrease in bone density than was monotherapy. Although few studies were available on bone growth, these did indicate that bone growth may be impaired among users of AEDs. Ketogenic diet may be associated with decreased bone density. The main determinant of normal BMD was absence of vitamin D deficiency/osteomalacia.

LIMITATIONS

The studies differed in skeletal sites studied and most were cross-sectional. No head-to-head comparisons of AEDs were performed. Children treated with polytherapy or ketogenic diet may have more complicated and severe disease than those treated with monotherapy. The underlying cause of epilepsy and vitamin D deficiency may contribute to impaired bone growth and density.

CONCLUSIONS

Reduced bone density, impaired bone growth, and vitamin D deficiency may be seen in children treated with drugs against epilepsy.

IMPLICATIONS

Measures to correct vitamin D deficiency, calcium intake should be taken.

Short-term effects of ketogenic diet on anthropometric parameters, body fat distribution, and inflammatory cytokine production in GLUT1 deficiency syndrome

OBJECTIVE

The aim of this study was to evaluate the effects of a 12-wk ketogenic diet (KD) on inflammatory status, adipose tissue activity biomarkers, and abdominal visceral (VAT) and subcutaneous fat (SAT) in children affected by glucose transporter 1 deficiency syndrome GLUT1 DS.

METHODS

We carried out a short-term longitudinal study on 10 children (mean age: 8.4 y, range 3.3-12 y, 5 girls, 5 boys) to determine fasting serum proinflammatory cytokines (high sensitivity C-reactive protein, tumor necrosis factor-α interleukin-6), adipocyte-derived chemokines (leptin and adiponectin), lipid profile, homeostatic model assessment-insulin resistance (HOMA-IR), quantitative insulin sensitivity index (QUICKI), anthropometric measurements, and VAT and SAT (by ultrasonography).

RESULTS

Children showed no significant changes in inflammatory and adipose tissue activity biomarkers, blood glucose, lipid profile, anthropometric measurements, VAT, and SAT. Fasting insulin decreased (6 ± 3.2 μU/mL versus 3 ± 2 μU/mL; P = 0.001), and both HOMA-IR and QUICKI indexes were significantly modified (1.2 ± 0.6 versus 0.6 ± 0.4; P = 0.002; 0.38 ± 0.03 versus 0.44 ± 0.05; P = 0.002, respectively).

CONCLUSIONS

Only HOMA-IR and QUICKI indexes changed after 12 wk on a KD, suggesting that over a short period of time KD does not affect inflammatory cytokines production and abdominal fat distribution despite being a high-fat diet. Long-term studies are needed to provide answers concerning adaptive metabolic changes during KD.