Kidney stones and the ketogenic diet: risk factors and prevention

The case for a ketogenic diet in the management of kidney disease

Ketogenic diets have been widely used for weight loss and are increasingly used in the management of type 2 diabetes. Despite evidence that ketones have multiple positive effects on kidney function, common misconceptions about ketogenic diets, such as high protein content and acid load, have prevented their widespread use in individuals with impaired kidney function. Clinical trial evidence focusing on major adverse kidney events is sparse. The aim of this review is to explore the effects of a ketogenic diet, with an emphasis on the pleiotropic actions of ketones, on kidney health. Given the minimal concerns in relation to the potential renoprotective effects of a ketogenic diet, future studies should evaluate the safety and efficacy of ketogenic interventions in kidney disease.

Drug resistant epilepsy and ketogenic diet: A narrative review of mechanisms of action

Drug-resistant epilepsy (DRE) poses a significant global challenge, impacting the well-being of patients. Anti-epileptic drugs often fail to effectively control seizures in individuals with DRE. This condition not only leads to persistent seizures but also induces neurochemical imbalances, elevating the risk of sudden unexpected death in epilepsy and comorbidities. Moreover, patients experience mood and personality alterations, educational and vocational setbacks, social isolation, and cognitive impairments. Ketogenic diet has emerged as a valuable therapeutic approach for DRE, having been utilized since 1920. Various types of ketogenic diets have demonstrated efficacy in controlling seizures. By having a multimodal mechanism of action, the ketogenic diet reduces neuronal excitability and the frequency of seizure episodes. In our narrative review, we have initially provided a concise overview of the factors contributing to drug resistance in epilepsy. Subsequently, we have discussed the different available ketogenic diets. We have reviewed the underlying mechanisms through which the ketogenic diet operates. These mechanisms encompass decreased neuronal excitability, enhanced mitochondrial function, alterations in sleep patterns, and modulation of the gut microbiome. Understanding the complex mechanisms by which this diet acts is essential as it is a rigorous diet and requires good compliance. Hence knowledge of the mechanisms may help to advance research on achieving similar therapeutic effects through other less stringent approaches.

Current Status and Prospects of Pediatric Stone Disease: A Bibliometric and Visualization Study

Pediatric stone disease, once considered rare, has emerged as a significant research area in the past two decades due to a sharp increase in its incidence. Understanding the evolving epidemiology and treatment strategies for pediatric stone disease is crucial for enhancing child health protection. This study aims to summarize the advancements in pediatric stone disease research over the last two decades through bibliometric analysis. We conducted a comprehensive search in the Web of Science Core Collection (WoSCC) for literature on pediatric stone disease from January 1, 2000 to February 20, 2024. Econometric analyses were performed using tools such as VOSviewer, CiteSpace, and the R package "bibliometrix." Our search yielded 1,208 publications, predominantly from the United States and Turkey, showing an annual increase in publications on pediatric stone disease. Leading research institutions include Dicle University, Children's Hospital of Philadelphia, and the University of Pennsylvania, with the Journal of Pediatric Urology publishing the highest number of articles. The most prolific authors were C.P. Nelson and B. Hoppe, with Caleb P. Nelson being the most co-cited author. Research themes primarily focused on risk factors and therapeutic approaches for pediatric stone disease. Emerging research hotspots are identified by keywords such as mechanism, mini-percutaneous nephrolithotomy, recurrence, and retrograde intrarenal surgery. The study forecasts a continued upward trend in global research on pediatric stone disease, with future studies likely to delve deeper into risk factors and novel therapeutic methods.

Ketogenic diet-produced β-hydroxybutyric acid accumulates brain GABA and increases GABA/glutamate ratio to inhibit epilepsy

Ketogenic diet (KD) alleviates refractory epilepsy and reduces seizures in children. However, the metabolic/cell biologic mechanisms by which the KD exerts its antiepileptic efficacy remain elusive. Herein, we report that KD-produced β-hydroxybutyric acid (BHB) augments brain gamma-aminobutyric acid (GABA) and the GABA/glutamate ratio to inhibit epilepsy. The KD ameliorated pentetrazol-induced epilepsy in mice. Mechanistically, KD-produced BHB, but not other ketone bodies, inhibited HDAC1/HDAC2, increased H3K27 acetylation, and transcriptionally upregulated SIRT4 and glutamate decarboxylase 1 (GAD1). BHB-induced SIRT4 de-carbamylated and inactivated glutamate dehydrogenase to preserve glutamate for GABA synthesis, and GAD1 upregulation increased mouse brain GABA/glutamate ratio to inhibit neuron excitation. BHB administration in mice inhibited epilepsy induced by pentetrazol. BHB-mediated relief of epilepsy required high GABA level and GABA/glutamate ratio. These results identified BHB as the major antiepileptic metabolite of the KD and suggested that BHB may serve as an alternative and less toxic antiepileptic agent than KD.

Risks of the ketogenic diet in CKD - the con part

The ketogenic diet is a very low carbohydrate diet that has received a lot of attention for its role in the treatment of type 2 diabetes and obesity. For patients with chronic kidney disease, there is limited evidence on the risks and/or benefits of this diet. However, from the limited evidence that does exist, there are several inferences that can be drawn regarding this diet for patients with kidney disease. The ketogenic diet may not be better than comparator higher carbohydrate diets over the long term. The diet also has low adherence levels in studies lasting ≥12 months. The diet's emphasis on fat, which often comes from animal fat, increases the consumption of saturated fat, which may increase the risk of heart disease. It has the potential to worsen metabolic acidosis by increasing dietary acid load and endogenous acid production through the oxidation of fatty acids. In addition, the diet has been associated with an increased risk of kidney stones in patients using it for the treatment of refractory epilepsy. For these reasons, and for the lack of safety data on it, it is reasonable for patients with kidney disease to avoid utilizing the ketogenic diet as a first-line option given alternative dietary patterns (like the plant-dominant diet) with less theoretical risk for harm. For those adopting the ketogenic diet in kidney disease, a plant-based version of the ketogenic diet may mitigate some of the concerns with animal-based versions of the ketogenic diet.

Management of Pediatric Urolithiasis in an Italian Tertiary Referral Center: A Retrospective Analysis

Background and Objectives: In recent years, the prevalence of pediatric urolithiasis has increased in North America and Western countries, though it is endemic in developing countries. The aim of this study is to describe the experience of a tertiary pediatric referral center in the surgical management of pediatric urolithiasis. Materials and Methods: We retrospectively reviewed the experience of patients ≤ 16 years old affected by urinary stones who underwent surgery. Results: From April 2021 to September 2023, 31 pediatric patients underwent surgical procedures for stone diseases at our department: 13 preschool-aged (1-5 years) and 18 school-aged (6-16 years) children. During this period, 12 URSs, 17 RIRSs, and 2 PCNLs were recorded. Five patients had residual fragments at first, so three of them underwent a second endourological lithotripsy (2 RIRSs and 1 URS). Complete clearance was finally achieved in 27 patients. The stone composition was evaluated in 25 cases. Conclusions: Numerous innovations in the surgical treatment of pediatric urolithiasis have resulted from the development of smaller devices and new technology. Our results show how, in experienced centers, retrograde and percutaneous lithotripsy are safe and effective procedures for use in pediatric populations.

Feasibility and impact of ketogenic dietary interventions in polycystic kidney disease: KETO-ADPKD-a randomized controlled trial

Ketogenic dietary interventions (KDIs) are beneficial in animal models of autosomal-dominant polycystic kidney disease (ADPKD). KETO-ADPKD, an exploratory, randomized, controlled trial, is intended to provide clinical translation of these findings (NCT04680780). Sixty-six patients were randomized to a KDI arm (ketogenic diet [KD] or water fasting [WF]) or the control group. Both interventions induce significant ketogenesis on the basis of blood and breath acetone measurements. Ninety-five percent (KD) and 85% (WF) report the diet as feasible. KD leads to significant reductions in body fat and liver volume. Additionally, KD is associated with reduced kidney volume (not reaching statistical significance). Interestingly, the KD group exhibits improved kidney function at the end of treatment, while the control and WF groups show a progressive decline, as is typical in ADPKD. Safety-relevant events are largely mild, expected (initial flu-like symptoms associated with KD), and transient. Safety assessment is complemented by nuclear magnetic resonance (NMR) lipid profile analyses.

Popular Diets and Kidney Stones

Popular diets often influence dietary patterns, which have different implications for kidney stone risk. Despite the wide variety of popular diets, some general principles can be gleaned from investigating their potential impact on nephrolithiasis. Plant-based diets, including Dietary Approaches to Stop Hypertension, Mediterranean, flexitarian, and vegetarian diets, may protect against nephrolithiasis when they consist largely of unprocessed plant foods, while carbohydrate-restricted diets (including high-protein diets and the ketogenic diet) may raise kidney stone risk. Patients should be advised to consume a diet rich in whole plants, particularly fruits and vegetables, and minimize their consumption of animal proteins. Accompanying fruits and vegetables that are higher in oxalate content with more water and some dairy intake may also be useful. (We address the oxalate content of fruits and vegetables further below). Calcium consumption is an important component of decreasing the risk of kidney stones, as higher dietary calcium from dairy or nondairy sources is independently associated with lower kidney stone risk. Patients should also be advised to be conscious of fat intake, as fat in the intestinal lumen may complex with calcium and therefore increase urinary oxalate excretion. Finally, patients should avoid consumption of processed foods, which often contain added fructose and high sodium content, two factors that increase kidney stone risk.

Ketogenic diet influence on the elemental homeostasis of internal organs is gender dependent

The ketogenic diet (KD) is a low-carbohydrate and high-fat diet that gains increasing popularity in the treatment of numerous diseases, including epilepsy, brain cancers, type 2 diabetes and various metabolic syndromes. Although KD is effective in the treatment of mentioned medical conditions, it is unfortunately not without side effects. The most frequently occurring undesired outcomes of this diet are nutrient deficiencies, the formation of kidney stones, loss of bone mineral density, increased LDL (low-density lipoprotein) cholesterol levels and hormonal disturbances. Both the diet itself and the mentioned adverse effects can influence the elemental composition and homeostasis of internal organs. Therefore, the objective of this study was to determine the elemental abnormalities that appear in the liver, kidney, and spleen of rats subjected to long-term KD treatment. The investigation was conducted separately on males and females to determine if observed changes in the elemental composition of organs are gender-dependent. To measure the concentration of P, S, K, Ca, Fe, Cu, Zn and Se in the tissues the method of the total reflection X-ray fluorescence (TXRF) was utilized. The obtained results revealed numerous elemental abnormalities in the organs of animals fed a high-fat diet. Only some of them can be explained by the differences in the composition and intake of the ketogenic and standard diets. Furthermore, in many cases, the observed anomalies differed between male and female rats.

Kidney Stones in Epileptic Children Receiving Ketogenic Diet: Frequency and Risk Factors

BACKGROUND

Although it is a valuable option for children with drug-resistant epilepsy, ketogenic diet (KD) therapy is associated with several side effects. The frequency of kidney stones and risk factors for their development in epileptic children receiving KD is unclear. The aim of this study was to determine the frequency and risk factors for the development of renal stones in children receiving KD therapy.

METHODS

A total of 95 patients receiving KD were identified. Of these, seven patients were excluded from the study due to the duration of KD being less than 12 months. The remaining 88 children were enrolled in the study.

RESULTS

Renal stones were detected in 15 patients (17%), of which 12 (73.3%) received potassium citrate treatment. Two (13.3%) patients needed lithotripsy despite receiving potassium citrate treatment, and one of these, who received potassium citrate treatment for 5 months, developed acute vesicourethral reflux and underwent surgery. No patient discontinued KD due to renal stone development. The serum uric acid concentrations and urine calcium/creatinine ratio did not change significantly over the 24-month follow-up period. Age, gender, etiology, age at seizure onset, duration of KD, mobility status, use of topiramate or zonisamide, and the number of antiepileptic drugs used were not significantly different between patients with and without kidney stones.

CONCLUSION

Renal stone appears to be a common adverse effect of KD therapy. Although adequate hydration and potassium citrate treatment are effective in most patients, lithotripsy and surgery may be required in a minority of patients.

Ketogenic Diet in Neonates with Drug-Resistant Epilepsy: Efficacy and Side Effects-A Single Center's Initial Experience

BACKGROUND

For patients with pharmacoresistant epilepsy, a therapeutic option is ketogenic diet. Currently, data on young infants are scarce, particularly during hospitalization in the neonatal intensive care unit (NICU).

OBJECTIVE

The aim of the present study was to evaluate the short-term (3-month) efficacy and side effects of ketogenic diet in infants with "drugs-resistant" epilepsy treated during NICU stay.

METHODS

This retrospective study included infants aged under 2 months started on ketogenic diet during NICU hospitalization to treat drug-resistant epilepsy from April 2018 to November 2022.

RESULTS

Thirteen term-born infants were included, three (23.1%) of whom were excluded because they did not respond to the ketogenic diet. Finally, we included 10 infants. Six (60%) patients took three antiepileptics before starting the ketogenic diet, while four (40%) took more drugs. Diet had a good response in four (40%) patients. In four patients, the ketogenic diet was suspended because of the onset of serious side effects. The emetic levels of sodium, potassium, and chlorine, pH, and onset of diarrhea, constipation, and gastroesophageal reflux showed significant differences. Ketonuria was higher and blood pH lower in the group that took more than three drugs than in the group taking fewer than three drugs.

CONCLUSION

The ketogenic diet is efficacious and safe in infants, but the early and aggressive management of adverse reactions is important to improve the safety and effectiveness of the ketogenic treatment.

The Influence of Ketogenic Diet on Gut Microbiota: Potential Benefits, Risks and Indications

The ketogenic diet (KD) restricts carbohydrate consumption, leading to an increase in ketone bodies, such as acetoacetate, β-hydroxybutyrate, and acetone, which are utilized as energy substrates. This dietary approach impacts several biochemical processes, resulting in improved clinical management of various disorders, particularly in childhood. However, the exact mechanisms underlying the efficacy of KD remain unclear. Interestingly, KD may also impact the gut microbiota, which plays a pivotal role in metabolism, nutrition, and the development of the immune and nervous systems. KD has gained popularity for its potential benefits in weight loss, blood sugar control, and certain neurological conditions. This narrative review sums up KD-related studies published over 30 years. While short-term studies have provided valuable insights into the effects of KD on the gut microbiota, persistent uncertainties surround its long-term efficacy and potential for inducing dysbiosis. The significant influence of KD on epigenetic mechanisms, intracellular pathways, and gut microbial composition underscores its potential as a therapeutic choice. However, a judicious consideration of the potential risks associated with the strict adherence to a low-carbohydrate, high-fat, and high-protein regimen over prolonged periods is imperative. As KDs gain popularity among the adolescent and young adult demographic for weight management, it becomes imperative to undertake additional research to comprehensively assess their impact on nutritional status and gut microbiota, ensuring a holistic and sustainable approach to medical nutrition.

Ketogenic dietary therapies in epilepsy: recommendations of the Italian League against Epilepsy Dietary Therapy Study Group

A stepwise increase in the utilization of ketogenic dietary therapies for drug-resistant epilepsy has been observed in Italy in the last decade, although it is still considered often underused in many centers when compared to other countries. The Dietary Therapy Study Group of the Italian League against Epilepsy proposes practical recommendations to improve shared knowledge and facilitate the application of ketogenic dietary therapies, optimizing its efficacy and tolerability. The experts involved (11 child neuropsychiatrists, two adult neurologists, one psychologist, one pharmacologist, one pediatric endocrinologist, one representative of patients' associations, and three dietitians and clinical nutritionists) responded to a survey on current clinical practice issues and were asked to discuss controversial topics related to supplementation, long-term maintenance, transition, and a multidisciplinary approach to ketogenic dietary therapies. Practical indications for patient selection, diet initiation, management, side effects prevention, and follow-up are provided.

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.

Why is childhood urolithiasis increasing? Etiology, diagnosis and management: a single-center experience

BACKGROUND

Globally, urolithiasis is becoming more and more common among children. We aimed to determine the etiology, and the diagnostic and therapeutic approaches in patients with urolithiasis.

METHODS

This was a retrospective study which included all patients (aged 1 month-18 years) admitted to the pediatric nephrology clinic in Elazığ Fethi Sekin City Hospital with urolithiasis between November 2019 and 2021. Only patients whose diagnosis of urolithiasis was confirmed by urinary ultrasonography were included in the study, while patients with chronic diseases (neurological diseases such as epilepsy, cerebral palsy, chronic bowel diseases, etc.) predisposing to kidney stone formation were not. Demographic characteristics, serum and urine biochemical parameters, urine metabolic and kidney stone metabolic and chemical analyses, urinary tract ultrasonography findings and treatment modalities were collected.

RESULTS

One hundred ninety-seven patients (91 female and 106 male) were included in the study. Hypervitaminosis D was detected in 4 (2%) patients, suppressed parathyroid hormone in 12 (6%) and hypercalcemia in 27 (14%) patients. Metabolic screening showed hypercalciuria in 69 (35%) patients, hypocitraturia in 39 (20%), hyperoxaluria in 15 (8%) and cystinuria in 6 (3%) patients. Eighty three (42%) patients had a positive family history for kidney stones. One hundred eighteen (60%) patients received potassium citrate treatment, 71 (36%) were given hydration and diet recommendations without medical treatment, 6 (3%) received tiopronin treatment, and 2 (1%) patients were treated surgically.

CONCLUSIONS

Our study suggests that Vitamin D supplementation at doses higher than 400 IU/day may be a risk factor for kidney stones in children. We observed that mothers tend not to give water to infants who are breastfed or formula-fed in the first year of life. K-citrate treatment can be a good option for prevention and dissolution of stones by alkalinization.

Ketogenic Diet in Children and Adolescents: the Effects on Growth and Nutritional Status

The ketogenic diet is known to be a possible adjuvant treatment in several medical conditions, such as in patients with severe or drug-resistant forms of epilepsy. Its use has recently been increasing among adolescents and young adults due to its supposed weight-loss effect, mediated by lipolysis and lowered insulin levels. However, there are still no precise indications on the possible use of ketogenic diets in pediatric age for weight loss. This approach has also recently been proposed for other types of disorder such as inherited metabolic disorders, Prader-Willi syndrome, and some specific types of cancers. Due to its unbalanced ratio of lipids, carbohydrates and proteins, a clinical evaluation of possible side effects with a strict evaluation of growth and nutritional status is essential in all patients following a long-term restrictive diet such as the ketogenic one. The prophylactic use of micronutrients supplementation should be considered before starting any ketogenic diet. Lastly, while there is sufficient literature on possible short-term side effects of ketogenic diets, their possible long-term impact on growth and nutritional status is not yet fully understood, especially when started in pediatric age.

The Role of Ketone Bodies in Various Animal Models of Kidney Disease

The kidney is a vital organ that carries out significant metabolic functions in our body. Due to the complexity of its role, the kidney is also susceptible to many disease conditions, such as acute kidney injury (AKI) and chronic kidney disease (CKD). Despite the prevalence and our increased understanding of the pathophysiology of both AKI and CKD as well as the transition of AKI to CKD, no well-established therapeutics have been applied clinically to these conditions, rendering an urgent need for a novel potential therapeutic target to be developed. In this article, we reviewed the function of ketone bodies in some common kidney conditions, such as drug-induced nephrotoxicity, ischemia and reperfusion injury, fibrosis development, diabetic kidney disease, kidney aging, hypertension, and CKD progression. All the selected studies reviewed were performed in animal models by primarily utilizing rodents, which also provide invaluable sources for future clinical applications. Ketone bodies have shown significant renal protective properties via attenuation of oxidative stress, increased expression of anti-inflammatory proteins, gene regulation, and a reduction of apoptosis of renal cells. A physiological level of ketone bodies could be achieved by fasting, a ketogenic diet, and an exogenous ketone supplement. Finally, the limitations of the long-term ketogenic diet were also discussed.

Insights into the Cellular Interactions and Molecular Mechanisms of Ketogenic Diet for Comprehensive Management of Epilepsy

A high-fat diet with appropriate protein and low carbohydrate content, widely known as the ketogenic diet (KD), is considered as an effective non-pharmacotherapeutic treatment option for certain types of epilepsies. Several preclinical and clinical studies have been carried out to elucidate its mechanism of antiepileptic action. Ketone bodies produced after KD's breakdown interact with cellular excito-inhibitory processes and inhibit abnormal neuronal firing. The generated ketone bodies decrease glutamate release by inhibiting the vesicular glutamate transporter 1 and alter the transmembrane potential by hyperpolarization. Apart from their effect on the well-known pathogenic mechanisms of epilepsy, some recent studies have shown the interaction of KD metabolites with novel neuronal targets, particularly adenosine receptors, adenosine triphosphate-sensitive potassium channel, mammalian target of rapamycin, histone deacetylase, hydroxycarboxylic acid receptors, and the NLR family pyrin domain containing 3 inflammasomes to suppress seizures. The role of KD in augmenting gut microbiota as a potential mechanism for epileptic seizure suppression has been established. Furthermore, some recent findings also support the beneficial effect of KD against epilepsy- associated comorbidities. Despite several advantages of the KD in epilepsy management, its use is also associated with a wide range of side effects. Hypoglycemia, excessive ketosis, acidosis, renal stones, cardiomyopathies, and other metabolic disturbances are the primary adverse effects observed with the use of KD. However, in some recent studies, modified KD has been tested with lesser side effects and better tolerability. The present review discusses the molecular mechanism of KD and its role in managing epilepsy and its associated comorbidities.

A Review of the Multi-Systemic Complications of a Ketogenic Diet in Children and Infants with Epilepsy

Ketogenic diets (KDs) are highly effective in the treatment of epilepsy. However, numerous complications have been reported. During the initiation phase of the diet, common side effects include vomiting, hypoglycemia, metabolic acidosis and refusal of the diet. While on the diet, the side effects involve the following systems: gastrointestinal, hepatic, cardiovascular, renal, dermatological, hematologic and bone. Many of the common side effects can be tackled easily with careful monitoring including blood counts, liver enzymes, renal function tests, urinalysis, vitamin levels, mineral levels, lipid profiles, and serum carnitine levels. Some rare and serious side effects reported in the literature include pancreatitis, protein-losing enteropathy, prolonged QT interval, cardiomyopathy and changes in the basal ganglia. These serious complications may need more advanced work-up and immediate cessation of the diet. With appropriate monitoring and close follow-up to minimize adverse effects, KDs can be effective for patients with intractable epilepsy.

The place of a ketogenic diet in the treatment of resistant epilepsy: a comprehensive review

Objective: The ketogenic diet (KD) is a high-fat, adequate-protein, and low-carb diet. Ketone bodies increase in the blood due to low carbohydrate content and high-fat content in the diet. The most important feature of the ketogenic diet is that it causes the production of ketone bodies in the liver. Ketone bodies are an alternative fuel to glucose for the brain and form the structure necessary for the cell membrane and biosynthesis of triglycerides. The ketogenic diet provides evidence on seizure control with anticonvulsant effects. In this review, the positive/negative effects of KD on seizure control, place, importance, quality of life, cognition, and behavior in the treatment of resistant epilepsy were examined.Methods: Scientific information on the subject was obtained from the literature accessed through databases such as MEDLINE, Embase, Web of Science, Cochrane Central, www.ClinicalTrials.gov, PubMed, Science Direct, and Google Scholar.Results: Although it has started to be used as a treatment method in many diseases today, the main area of effect of KD is drug-resistant epilepsy. In order for the ketogenic diet to be successful in these patients, it is necessary to choose the appropriate patient, medical treatment and diet plan, inform the patient sufficiently, and perform frequent monitoring in accordance with the follow-up criteria. It is argued that KD is one of the most effective treatments for epilepsy.Conclusion: The fact that KDs generally have a restricted diet pattern, the need for supplementation, biochemical findings and possible side effects raise the issue of diet sustainability. More clinical studies are needed to generalize.

Nutritional Deficiencies in Vegetarian, Gluten-Free, and Ketogenic Diets

Previously, medical diets, including the ketogenic and gluten-free diets, were rare outside of their target population. Subspecialists more familiar with risks and benefits often managed nutrition and any associated shortcomings. With more patients electively following a gluten-free or ketogenic diet for nonmedical needs, as well as the increasing prevalence of vegetarian diets, general pediatricians are seeing more followers of restrictive diets with general well-child care. Increasingly, general pediatricians can be the first provider to witness presenting signs or symptoms of associated nutritional deficiencies. This article reviews signs and symptoms of possible nutrient deficiencies seen with the vegetarian, ketogenic, and gluten-free diets.

Modified Atkins diet for drug-resistant epilepsy and the risk of urolithiasis

BACKGROUND

Ketogenic diet (KD) is widely used for drug-resistant epilepsy (DRE). The study was designed to evaluate one of the risk factors for development of renal calculi with KD.

METHODS

Twenty patients with DRE on Modified Atkins diet (MAD) were subjected to full history and laboratory investigations, including microscopic urine analysis, urinary calcium after overnight fasting, and calcium/creatinine ratio, as well as pelviabdominal ultrasound. Frequency and severity of seizures assessed by Chalfont severity score were recorded. All assessment measures were repeated after 3 and 6 months of KD therapy.

RESULTS

There were significant reductions in both frequency and severity of seizures, yet 2 patients (10%) developed renal stones after 6 months on KD. Gross hematuria was reported in 1 of those 2 patients (50%), but microscopic hematuria was detected in both patients. The urine calcium and the urine calcium/creatinine ratio were elevated in both patients having renal calculi after 6 months.

CONCLUSIONS

KD increases the risk of renal stones with hypercalciuria among the causes. We recommend initiation of prophylactic measures once KD is commenced by maximizing fluid intake and urine alkalinization with regular urinary studies including calcium/creatinine ratio and renal ultrasound for patients with symptoms.

IMPACT

KD has been increasingly used in epilepsy management and beyond. The potential side effects of such diet should be highlighted while valuing the merits. KD increases the risk of renal stones because of hypercalciuria among other causes. We recommend initiation of prophylactic measures once KD is commenced by maximizing fluid intake and urine alkalinization with estimation of urinary calcium/creatinine ratio and renal ultrasound in patients with relevant symptoms.

The Relationship between Modern Fad Diets and Kidney Stone Disease: A Systematic Review of Literature

Objectives: Kidney stone disease (KSD) has a strong association with diet metabolic syndrome. This review aims at exploring the lithogenic risk posed by the current most popular diets. Our approach was to search for the effect of each diet type on the major urinary risk factors, to try to draw conclusions regarding the association of a specific diet type and KSD. Methods: This systematic review searched for the available literature exploring the association between the existing popular fad diets and KSD. Articles in English, French and Spanish were included, without restriction of the search period with the final search done in August 2021. Results: Total number of studies and studies for each diet type was as follows: 22 articles for the low carbohydrate diet, 20 articles for high protein diets, 26 articles for vegetarian and vegan diets. There exists a substantial variability in different low carbohydrate and high protein diets, and considerable overlap between modern popular fad diets. High carbohydrate intake might increase urine uric acid, calcium and oxalate levels. High protein diets increase urine calcium and uric acid and lower urine pH and citrate. Consumption of fruits and vegetables increases the urinary volume and urinary citrate. In vegan diets, sufficient daily calcium intake is important to avoid possible secondary hyperoxaluria. Conclusions: Few studies evaluated the direct relationship between modern fad diets and KSD. In general, the reduction of carbohydrate in the diet, and counterbalancing protein rich diets with sufficient intake of fruits and vegetables, seem to play a protective role against KSD formation. Maintaining sufficient calcium intake in vegan and vegetarian diets is important. Additional research is needed to directly evaluate the link between KSD and each diet type.

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.

Ketogenic dietary interventions in autosomal dominant polycystic kidney disease-a retrospective case series study: first insights into feasibility, safety and effects

Background

Our laboratory published the first evidence that nutritional ketosis, induced by a ketogenic diet (KD) or time-restricted diet (TRD), ameliorates disease progression in polycystic kidney disease (PKD) animal models. We reasoned that, due to their frequent use for numerous health benefits, some autosomal dominant PKD (ADPKD) patients may already have had experience with ketogenic dietary interventions (KDIs). This retrospective case series study is designed to collect the first real-life observations of ADPKD patients about safety, feasibility and possible benefits of KDIs in ADPKD as part of a translational project pipeline.

Methods

Patients with ADPKD who had already used KDIs were recruited to retrospectively collect observational and medical data about beneficial or adverse effects and the feasibility and safety of KDIs in questionnaire-based interviews.

Results

A total of 131 ADPKD patients took part in this study. About 74 executed a KD and 52 a TRD for 6 months on average. A total of 86% of participants reported that KDIs had improved their overall health, 67% described improvements in ADPKD-associated health issues, 90% observed significant weight loss, 64% of participants with hypertension reported improvements in blood pressure, 66% noticed adverse effects that are frequently observed with KDIs, 22 participants reported safety concerns like hyperlipidemia, 45 participants reported slight improvements in estimated glomerular filtration rate and 92% experienced KDIs as feasible while 53% reported breaks during their diet.

Conclusions

Our preliminary data indicate that KDIs may be safe, feasible and potentially beneficial for ADPKD patients, highlighting that prospective clinical trials are warranted to confirm these results in a controlled setting and elucidate the impact of KDIs specifically on kidney function and cyst progression.

Metabolic Derangement in Pediatric Patient with Obesity: The Role of Ketogenic Diet as Therapeutic Tool

Obesity is defined as a condition characterized by an excessive fat accumulation that has negative health consequences. Pediatric obesity is associated with an increased risk for many diseases, including impaired glycemic and lipidic control that may lead to the development of chronic, and potentially disabling, pathologies, such as type 2 diabetes mellitus (T2DM) and cardiovascular events, in adult life. The therapeutic strategy initially starts with interventions that are aimed at changing lifestyle and eating behavior, to prevent, manage, and potentially reverse metabolic disorders. Recently, the ketogenic diet (KD) has been proposed as a promising dietary intervention for the treatment of metabolic and cardiovascular risk factors related to obesity in adults, and a possible beneficial role has also been proposed in children. KD is very low in carbohydrate, high in fat, and moderate to high in protein that may have the potential to promote weight loss and improve lipidic derangement, glycemic control, and insulin sensitivity. In this review, we present metabolic disorders on glycemic and lipidic control in children and adolescents with obesity and indication of KD in pediatrics, discussing the role of KD as a therapeutic tool for metabolic derangement. The results of this review may suggest the validity of KD and the need to further research its potential to address metabolic risk factors in pediatric obesity.

The Efficacy of Ketogenic Therapies in the Clinical Management of People with Neurodegenerative Disease: A Systematic Review

Ketone bodies have potential disease-modifying activity that represent a novel therapeutic approach for neurodegenerative diseases (NDD). The aim of this systematic review was to summarize and evaluate the evidence for the application of ketogenic therapies (dietary or exogenous ketogenic agents) for NDD and provide recommendations for future research. Eight databases were electronically searched for articles reporting on controlled trials (≥4 wk duration) that induced ketosis or elevated serum ketone concentrations in people with NDD. Of 4498 records identified, 17 articles met the inclusion criteria with a total of 979 participants including studies on mild cognitive impairment (MCI; n = 6), multiple sclerosis (n = 4), Alzheimer's disease (n = 5), Parkinson's disease (n = 1), and MCI secondary to Parkinson's disease (n = 1). Of 17 studies, 7 were randomized double-blind placebo-controlled trials. Most studies used dietary interventions (n = 9), followed by medium-chain triglycerides (n = 7) and a fasting protocol (n = 1). Generally, trials were 6 wk in duration and assessed cognition as the primary outcome. Studies were heterogeneous in type and severity of NDD, interventions used, and outcomes assessed. Overall, 3/17 studies carried a low risk of bias. Based on available evidence, exogenous ketogenic agents may be more feasible than dietary interventions in NDD from a compliance and adherence perspective; more research is required to confirm this. Recommendations for future research include improving exogenous formulations to reduce adverse effects, exploring interindividual factors affecting response-to-treatment, and establishing a "minimum required dose" for clinically meaningful improvements in disease-specific symptoms, such as cognition or motor function.

[Ketogenic dietary therapies for epilepsy: Experience in 160 patients over 18 years]

AIM

Ketogenic dietary therapies (KDT) produce anticonvulsant and neuroprotective effects, reduce seizures and improve the cognitive state in patients with epilepsy. Our purpose was to evaluate the effects of KDT in children with refractory epilepsy (effectiveness, side effects, impact on nutritional status and growth).

METHODS

A retrospective and prospective observational descriptive study was conducted in a Spanish tertiary hospital (January 2000 to December 2018). One hundred sixty pediatric patients with epilepsy were treated with KDT (82 males; mean age 5 years 9 months). Seizures, anti-epileptic drugs, anthropometric measures, side effects, and laboratory assessment were monitored baseline and at 3, 6, 12 and 24 months after the onset of KDT.

RESULTS

In these time intervals, the seizure-free patients were: 13.7, 12.5, 14.4 and 10.6%, respectively, and a reduction of seizures≥50% was achieved in 41.9, 37.5, 28.7 and 16.2%. Side effects were frequent, especially digestive disorders, hypercalciuria, hypoglycemia, hepatic dysfunction and dyslipidemia. Prealbumin, retinol binding protein, vitamin A and magnesium decreased significantly. Height was affected, especially in children below 2 years.

CONCLUSIONS

KDT are effective for refractory epilepsy in children. However, adverse effects are frequent, and it may affect nutritional status and growth.

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.

The Chemistry of the Ketogenic Diet: Updates and Opportunities in Organic Synthesis

The high-fat, low-carbohydrate (ketogenic) diet has grown in popularity in the last decade as a weight loss tool. Research into the diet’s effects on the body have revealed a variety of other health benefits. The use of exogenous ketone supplements to confer the benefits of the diet without strict adherence to it represents an exciting new area of focus. Synthetic ketogenic compounds are of particular interest that has received very little emphasis and is an untapped area of focus for chemical synthesis. In this review, we summarize the chemical basis for ketogenicity and opportunities for further advancement of the field.

3-Hydroxybutyrate as a Metabolite and a Signal Molecule Regulating Processes of Living Organisms

3-hydroxybutyrate (3-HB) as a very important metabolite occurs in animals, bacteria and plants. It is well known that in animals, 3-HB is formed as a product of the normal metabolism of fatty acid oxidation and can therefore be used as an energy source in the absence of sufficient blood glucose. In microorganisms, 3-HB mainly serves as a substrate for the synthesis of polyhydroxybutyrate, which is a reserve material. Recent studies show that in plants, 3-HB acts as a regulatory molecule that most likely influences the expression of genes involved in DNA methylation, thereby altering DNA methylation levels. Additionally, in animals, 3-HB is not only an intermediate metabolite, but also an important regulatory molecule that can influence gene expression, lipid metabolism, neuronal function, and overall metabolic rate. Some of these effects are the direct effects of 3-HB itself, while others are indirect effects, regulated by the metabolites into which 3-HB is converted. One of the most important regulatory functions of 3-HB is the inhibition of the activity of histone deacetylases and thus the epigenetic regulation of many genes. Due to the number of functions of this compound, it also shows promising therapeutic properties.

Classic Ketogenic Diet and Modified Atkins Diet in SLC2A1 Positive and Negative Patients with Suspected GLUT1 Deficiency Syndrome: A Single Center Analysis of 18 Cases

Background: Glucose transporter type 1 deficiency syndrome (GLUT1DS) is caused by mutations in the SLC2A1 gene and produces seizures, neurodevelopmental impairment, and movement disorders. Ketogenic dietary therapies (KDT) are the gold standard treatment. Similar symptoms may appear in SLC2A1 negative patients. The purpose is to evaluate the effectiveness of KDT in children with GLUT1DS suspected SLC2A1 (+) and (-), side effects (SE), and the impact on patients nutritional status. Methods: An observational descriptive study was conducted to describe 18 children (January 2009–August 2020). SLC2A1 analysis, seizures, movement disorder, anti-epileptic drugs (AEDS), anthropometry, SE, and laboratory assessment were monitored baseline and at 3, 6, 12, and 24 months after the onset of KDT. Results: 6/18 were SLC2A1(+) and 13/18 had seizures. In these groups, the age for debut of symptoms was higher. The mean time from debut to KDT onset was higher in SLC2A1(+). The modified Atkins diet (MAD) was used in 12 (5 SLC2A1(+)). Movement disorder improved (4/5), and a reduction in seizures >50% compared to baseline was achieved in more than half of the epileptic children throughout the follow-up. No differences in effectiveness were found according to the type of KDT. Early SE occurred in 33%. Long-term SE occurred in 10, 5, 7, and 5 children throughout the follow-up. The most frequent SE were constipation, hypercalciuria, and hyperlipidaemia. No differences in growth were found according to the SLC2A1 mutation or type of KDT. Conclusions: CKD and MAD were effective for SLC2A1 positive and negative patients in our cohort. SE were frequent, but mild. Permanent monitoring should be made to identify SE and nutritional deficits.

Hypercalcemia in Children Using the Ketogenic Diet: A Multicenter Study

CONTEXT

The ketogenic diet is associated with progressive skeletal demineralization, hypercalciuria, and nephrolithiasis. Acute hypercalcemia has been described as a newly recognized complication of this treatment.

OBJECTIVE

To describe the clinical characteristics of acute hypercalcemia in children on the ketogenic diet through analysis of the presentation, response to treatment, and natural history in a large cohort of patients.

DESIGN

A multicenter case series was performed including children who developed acute hypercalcemia while treated with the ketogenic diet. Information on clinical presentation, treatment, and course of this complication was collated centrally.

RESULTS

There were 14 patients (median (range) age 6.3 (0.9 to 18) years) who developed hypercalcemia 2.1 (range, 0.2-12) years after starting the ketogenic diet. All had low levels of parathyroid hormone and levels of 1,25-dihydroxyvitamin D were low in all except one. Seven (50%) had impaired renal function at presentation. All except the 2 oldest had low alkaline phosphatase levels for age. Once normocalcemia was achieved, hypercalcemia recurred in only 2 of these patients over observation of up to 9.8 years. One patient discontinued the ketogenic diet prior to achieving normocalcemia while 4 more stopped the diet during follow-up after resolution of hypercalcemia.

CONCLUSIONS

Ketotic hypercalcemia can occur years after starting the ketogenic diet, especially in the setting of renal impairment. The mechanism is unknown but appears to be due to reduced osteoblast activity and impaired bone formation. We recommend close attention to optimizing bone health in these children, and screening for the development of ketotic hypercalcemia.

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.

Possible interplay between the theories of pharmacoresistant epilepsy

Epilepsy is one of the oldest known neurological disorders and is characterized by recurrent seizure activity. It has a high incidence rate, affecting a broad demographic in both developed and developing countries. Comorbid conditions are frequent in patients with epilepsy and have detrimental effects on their quality of life. Current management options for epilepsy include the use of anti-epileptic drugs, surgery, or a ketogenic diet. However, more than 30% of patients diagnosed with epilepsy exhibit drug resistance to anti-epileptic drugs. Further, surgery and ketogenic diets do little to alleviate the symptoms of patients with pharmacoresistant epilepsy. Thus, there is an urgent need to understand the underlying mechanisms of pharmacoresistant epilepsy to design newer and more effective anti-epileptic drugs. Several theories of pharmacoresistant epilepsy have been suggested over the years, the most common being the gene variant hypothesis, network hypothesis, multidrug transporter hypothesis, and target hypothesis. In our review, we discuss the main theories of pharmacoresistant epilepsy and highlight a possible interconnection between their mechanisms that could lead to the development of novel therapies for pharmacoresistant epilepsy.

Effectiveness of Ketogenic Diets on the Survival of Adult Oncological Patients

Cancer is the second most prevalent disease worldwide and it presents characteristic hallmarks common to all its types. Within these, it has been described a reprogramming of its energy metabolism, characterized by the preferential use of glucose as energy source in an aerobic glycolysis process. Although this feature may provide adaptive advantages to tumoral cells, it has been described as a weakness that could make them more vulnerable. The ketogenic diet, characterized by high fat and very low carbohydrate intake, aims to eliminate glucose, the main fuel used by cancer cells. Animal studies have described promising results in terms of survival and regression of tumor size; nonetheless, these have failed to replicate in human studies. Furthermore, the ketogenic diet presents possible adverse effects when used in the long term, which should be considered in a vulnerable population such as cancer patients. To date, there is no solid evidence to demonstrate the effectiveness of the ketogenic diet in tumor progression or in overall survival of cancer patients, since most of the studies are observational, uncontrolled, and of short duration. At the moment, we only have limited data to guide us, and at the same time, to promote further study of this approach as a therapeutic opportunity.

Nephrolithiasis: Approach to Diagnosis and Management

Although kidney stones are less common in children than in adults, incidence in children is rising. Kidney stones may lead to significant morbidity in addition to escalating medical costs. Clinical presentation is variable. Bilateral kidney stones in a younger child should prompt work-up for primary hyperoxaluria. Metabolic abnormalities are more frequent in children and can result in frequent stone recurrence. Whole exome sequencing data shows genetic defects in about 30% of stone formers. 24 h urine collection should be conducted when patient receives his usual diet and fluid intake with normal activity. Infrared spectroscopy and X-ray diffraction are used for stone analysis. Urine studies should be delayed by 4-6 wk after stone fragmentation or treatment of any stone related complications. The goal of evaluation is to identify modifiable risk factors for which targeted therapy may be instituted. Primary indications for surgical intervention include pain, infection and obstruction. Extracorporeal shockwave lithotripsy (ESWL), ureteroscopy, and percutaneous nephrolithotomy (PCNL) are most commonly used, and selection is based on stone size, anatomy, composition and anatomy. Advances in technology have allowed a shift to minimally invasive surgeries. Comprehensive management requires multidisciplinary team. Children with kidney stones require long term follow-up with periodic assessment of stone forming activity and ascertaining stone burden. High index of suspicion should be there to diagnose diseases like primary hyperoxaluria, Dent's disease, renal tubular acidosis (RTA) etc. as these diseases have ramifications on kidney function and growth.

Ketogenic diet treatment of children in the intensive care unit: Safety, tolerability, and effectiveness

PURPOSE

The ketogenic diet (KD) is initiated emergently in the intensive care unit (ICU) for patients with super refractory status epilepticus (SRSE) and epileptic encephalopathies (EE). However, few data are available regarding safety, effectiveness, and long-term outcomes.

METHODS

We performed a retrospective cohort study of consecutive patients with KD initiated in the ICU from 2010 to 2018 for SRSE and EE. We characterized time to ketosis, adverse effects, and seizure outcomes. Responders were defined as having ≥50 % reduction in seizure frequency compared to prior to KD initiation.

RESULTS

We identified 29 patients. KD was initiated for SRSE in 12 patients, EE in 8 patients, and EE with SRSE in 9 patients. KD was initiated after a median of 9 days. Ketosis was achieved 2 days faster in fasted patients (p < 0.0001). All patients had at least 1 KD-related adverse effect, most often hypoglycemia, constipation, or acidosis. There was ≥50 % reduction in seizure frequency compared to prior to KD initiation by 1 week in 17/28 patients, seizure-freedom by 2 weeks in 7/28 patients, and weaned off anesthetics in 11/17 patients. All KD-responders at 1 month had continued response at 6 months. Mortality at 1 year was 24 %. There was no difference in KD response or mortality between KD indication groups.

CONCLUSION

Emergent KD initiation in the ICU is feasible, safe, and often effective for SRSE and EE. Expected adverse effects were common but treatable. Morbidity and mortality in this group was high. A ≥ 50 % reduction in seizure is achieved in most responders by 1-2 weeks.

Efficacy and Safety of a Ketogenic Diet in Children and Adolescents with Refractory Epilepsy-A Review

Epilepsy in the pediatric and adolescent populations is a devastating condition where individuals are prone to recurrent epileptic seizures or changes in behavior or movement that is the direct result of a primary change in the electrical activity in the brain. Although many children with epilepsy will have seizures controlled with antiseizure medications (ASMs), a large percentage of patients are refractory to drug therapy and may consider initiating a ketogenic diet. The term Ketogenic Diet or Ketogenic Diet Therapy (KDT) refers to any diet therapy in which dietary composition results in a ketogenic state of human metabolism. Currently, there are 4 major Ketogenic diet therapies—the classic ketogenic diet (cKD), the modified Atkins diet (MAD), the medium chain triglyceride ketogenic diet (MCTKD) and the low glycemic index treatment (LGIT). The compositions of the 4 main KDTs differ and limited evidence to distinguish the efficacy among different diets currently exists. Although it is apparent that more randomized controlled trials (RCTs) and long-term studies are needed to evaluate efficacy, side effects and individual response to the diet, it is imperative to study and understand the metabolic profiles of patients with epilepsy in order to isolate which dietary restrictions are necessary to maximize clinical benefit.

Effects of an Omega-3 and Vitamin D Supplement on Fatty Acids and Vitamin D Serum Levels in Double-Blinded, Randomized, Controlled Trials in Healthy and Crohn's Disease Populations

Two trials separately measured the bioavailability and impact on inflammation of a supplement taken daily containing 510 mg Docosahexaenoic acid (DHA), 344 mg Eicosapentaenoic acid (EPA), and 1000 IU of vitamin D (25-hydroxyvitamin D; 25(OH)D), for healthy and Crohn’s disease (CD) populations. Both trials were double blinded, randomized, placebo-controlled with cross-over. Participants were randomly allocated to groups A (placebo then supplement) or B (supplement then placebo). Both included a washout. Fatty acid (N-3 PUFAs) and vitamin D serum levels, plasma C-reactive protein (CRP), and stool calprotectin were measured before and after each treatment period. Outcome measures were analyzed using generalized linear mixed models, including terms for treatment, period, and a treatment-by-period interaction. The supplement significantly increased serum levels in healthy and CD groups for EPA (p < 0.001 and p < 0.001, respectively), Docosapentaenoic acid (p < 0.001 and 0.005), DHA (p < 0.001 and 0.006), the omega-3 index (p < 0.001 and 0.001), and (vitamin D (p < 0.001 and 0.027). CRP and calprotectin measures showed no evidence of a treatment effect on inflammation; however, model estimation was imprecise for both outcomes, hence further research is required to elucidate potential inflammation effects. The nutrient supplement increased serum levels of key N-3 PUFAs and vitamin D in both populations, showing the preparation was readily bioavailable.

Safety and Effectiveness of the Prolonged Treatment of Children with a Ketogenic Diet

Background: The ketogenic diet (KD) is an effective treatment against drug-resistant epilepsy in children. The KD is a diet rich in fats that produces anticonvulsant and neuroprotective effects that reduces seizures and improves the cognitive state. Nevertheless, it can produce side effects that sometimes can be serious. Further, the effect on growth is quite controversial when used for an extended period of time. The aim of this paper was to assess the effectiveness, side effects, and repercussions in the development of children who have been treated with a KD for more than 2 years. Methods: Observational descriptive study of 26 pediatric patients on a KD, with data collection at baseline, at 3, 6, and 12 months, and then once a year. Number of seizures, type of seizures, anti-seizure drugs, anthropometry, side effects, and alterations in laboratory assessment were monitored. Results: In every assessment, about 60%–75% of the patients experienced a reduction in number of seizures of over 90%, and at least 50% experienced side effects, of which digestive issues, alteration in the lipid metabolism, and hypercalciuria were the most common. The KD significantly affected height after 2 years of treatment. Conclusions: The KD is an effective treatment for drug-resistant epilepsy. Its side effects, although common, are very mild; therefore, this constitutes a very safe treatment for children of all ages. More studies are needed to identify and prevent potential causes of growth retardation in children on the KD.

Potassium citrate and metabolic acidosis in children with epilepsy on the ketogenic diet: a prospective controlled study

AIM

To investigate if potassium citrate, a mild alkaline compound, can prevent metabolic acidosis in children with epilepsy treated with the ketogenic diet without reducing antiepileptic efficacy.

METHOD

In this prospective controlled study, we investigated the frequency of initial uncompensated metabolic acidosis in 51 participants. There were 22 participants with and 29 without potassium citrate supplementation. The ketogenic diet was used as add-on treatment to children with drug resistant epilepsy. We also estimated the proportion of participants with a greater than 50% seizure reduction after 7 months.

RESULTS

None of the 22 participants (15 males, seven females; median age 1y 7mo, interquartile range [IQR] 3y 3mo) with, and 10 of 29 (12 males, 17 females; median age 6y 1mo, IQR 4y 8mo) without potassium citrate developed metabolic acidosis (odds ratio=0.04, 95% CI 0.00-0.75 [p<0.01]); median pH 7.32 vs 7.24; [p<0.001]), and median bicarbonate 19.7mmol/L vs 14.0mmol/L (p<0.001). The number of seizures was reduced by more than 50% in 9 of 22 with potassium citrate and 8 of 29 participants without potassium citrate, 7 months after introducing a ketogenic diet (p=0.4).

INTERPRETATION

In the ketogenic diet, potassium citrate supplementation can prevent metabolic acidosis, without reducing antiepileptic efficacy.

WHAT THIS PAPER ADDS

Citrate supplementation prevents metabolic acidosis in children treated with a ketogenic diet. Efficacy of the ketogenic diet is not affected by supplementation with citrate. Citrate supplementation does not affect beta-hydroxybuturate concentration. Potassium citrate reduces the time needed to reach an optimal ketogenic ratio. This article is commented on by Schoeler on page 8 of this issue.

Drug-Induced Urolithiasis in Pediatric Patients

Drug-induced nephrolithiasis is a rare condition in children. The involved drugs may be divided into two different categories according to the mechanism involved in calculi formation. The first one includes poorly soluble drugs that favor the crystallization and calculi formation. The second category includes drugs that enhance calculi formation through their metabolic effects. The diagnosis of these specific calculi depends on a detailed medical history, associated comorbidities and the patient's history of drug consumption. There are several risk factors associated with drug-induced stones, such as high dose of consumed drugs and long duration of treatment. Moreover, there are some specific risk factors, including urinary pH and the amount of fluid consumed by children. There are limited data regarding pediatric lithogenic drugs, and hence, our aim was to perform a comprehensive review of the literature to summarize these drugs and identify the possible mechanisms involved in calculi formation and discuss the management and preventive measures for these calculi.

Ketogenic Diets and Exercise Performance

The ketogenic diet (KD) has gained a resurgence in popularity due to its purported reputation for fighting obesity. The KD has also acquired attention as an alternative and/or supplemental method for producing energy in the form of ketone bodies. Recent scientific evidence highlights the KD as a promising strategy to treat obesity, diabetes, and cardiac dysfunction. In addition, studies support ketone body supplements as a potential method to induce ketosis and supply sustainable fuel sources to promote exercise performance. Despite the acceptance in the mainstream media, the KD remains controversial in the medical and scientific communities. Research suggests that the KD or ketone body supplementation may result in unexpected side effects, including altered blood lipid profiles, abnormal glucose homeostasis, increased adiposity, fatigue, and gastrointestinal distress. The purpose of this review article is to provide an overview of ketone body metabolism and a background on the KD and ketone body supplements in the context of obesity and exercise performance. The effectiveness of these dietary or supplementation strategies as a therapy for weight loss or as an ergogenic aid will be discussed. In addition, the recent evidence that indicates ketone body metabolism is a potential target for cardiac dysfunction will be reviewed.

Food and Food Products on the Italian Market for Ketogenic Dietary Treatment of Neurological Diseases

The ketogenic diet (KD) is the first line intervention for glucose transporter 1 deficiency syndrome and pyruvate dehydrogenase deficiency, and is recommended for refractory epilepsy. It is a normo-caloric, high-fat, adequate-protein, and low-carbohydrate diet aimed at switching the brain metabolism from glucose dependence to the utilization of ketone bodies. Several variants of KD are currently available. Depending on the variant, KDs require the almost total exclusion, or a limited consumption of carbohydrates. Thus, there is total avoidance, or a limited consumption of cereal-based foods, and a reduction in fruit and vegetable intake. KDs, especially the more restrictive variants, are characterized by low variability, palatability, and tolerability, as well as by side-effects, like gastrointestinal disorders, nephrolithiasis, growth retardation, hyperlipidemia, and mineral and vitamin deficiency. In recent years, in an effort to improve the quality of life of patients on KDs, food companies have started to develop, and commercialize, several food products specific for such patients. This review summarizes the foods themselves, including sweeteners, and food products currently available for the ketogenic dietary treatment of neurological diseases. It describes the nutritional characteristics and gives indications for the use of the different products, taking into account their metabolic and health effects.

Antiobesity and Uric Acid-Lowering Effect of Lactobacillus plantarum GKM3 in High-Fat-Diet-Induced Obese Rats

Objective: Obesity has become one of the world's biggest issues. This condition has a great impact on several metabolic and chronic diseases. For example, obesity is often accompanied by hyperuricemia or gout. However, few drugs are available for the treatment of obesity. The present study is to evaluate the antiobesity effect of Lactobacillus plantarum GKM3 in high-fat-diet-induced obese rats and whether taking L plantarum GKM3 can effectively reduce uric acid accumulation caused by obesity and ameliorate other harmful factors. Method: Sixty male Wistar rats were divided into five groups as follows: ( 1 ) ND group, fed normal diet; ( 2 ) HFC group, fed AIN93G-based high-fat diet containing 65% solids, 7% soybean oil, and 25% lard; ( 3 ) HFL group, fed AIN93G-based high-fat diet supplemented with 102.7 mg/kg/d L plantarum GKM3; ( 4 ) HFM group, fed AIN93G-based high-fat diet supplemented with 205.4 mg/kg/d L plantarum GKM3; and ( 5 ) HFH group, fed AIN93G-based high-fat diet supplemented with 513.5 mg/kg/d L plantarum GKM3. After 6 weeks, the body, organ, and fat weights; food intake; blood serum levels; and adipocyte size were measured. Results: Results showed that rats fed on the high-fat diet showed more body weight, increased feed efficiency, higher fat deposition, higher total liver weight, elevated serum lipid levels, and increased adipocyte size compared with those on the normal diet. All these effects were reversed by supplementation of L plantarum GKM3. Conclusions: In conclusion, we suggest that the L plantarum GKM3 supplement may have beneficial antiobesity and uric acid-lowering effects.

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.

Current Perspectives On The Role Of The Ketogenic Diet In Epilepsy Management

Drug-refractory epilepsy is a commonly prevalent pediatric neurological illness of global significance. Ketogenic diet (KD) is a time-tested therapeutic modality for refractory epilepsy, which has reemerged as a robust alternative to anti-epileptic pharmacotherapy. There is a growing body of evidence which supports the anti-seizure efficacy, safety profile and feasibility of KD use in childhood epilepsy. In addition, this modality has been recognized to reduce anti-epileptic exposure, improve cognition and behavioral profile of patients as well as improve the quality-of-life of care-givers. Current indications of KD include refractory epilepsy syndromes, selected metabolic disorders (such as pyruvate dehydrogenase deficiency) and a host of varied neurological entities. KD research has broadened the knowledge-base about its mechanisms of action. Four types of KD are in vogue currently with varying nutritional constitution, palatability, administration protocols and comparable efficacy. KD initiation and maintenance are the result of concerted effort of a team of pediatric neurologist/epileptologist, nutritionist and patient's primary care-giver. Consensus is being formulated about various practical aspects of KD such as patient-selection, parental counseling, baseline work-up, dietary prescription, nutritional supplementation, concurrent anti-epileptic drug administration, follow-up and treatment-duration. Novel applications of KD include its use in neonatal epilepsy and super-refractory status epilepticus and tailor-made formulations such as cooking oil-based KD in predominantly rice-fed populations. Increasing body of clinical experience, improved nutritional designs and translational research are promoting KD as a major therapeutic modality. Currently, KD forms a core essence in the armamentarium against refractory epilepsy. In this review, we summarize the recent advances and current perspectives in the use of KD in refractory epilepsy.