Serum Levels Of Ketone Bodies Research Articles

A multicenter, open-label, single-arm trial of the long-term safety of empagliflozin treatment for refractory diabetes mellitus with insulin resistance (EMPIRE-02).

Insulin resistance syndrome and lipoatrophic diabetes are rare conditions characterized by the development of treatment-refractory diabetes with severe insulin resistance. We recently conducted a 24 week, multicenter, single-arm trial (EMPIRE-01) that demonstrated a certain level of effectiveness and safety of empagliflozin for these conditions. To evaluate treatment safety over a longer period, we have now performed an additional 28 week trial (EMPIRE-02) that followed on from EMPIRE-01. The primary and secondary outcomes were safety and efficacy evaluations, respectively. All eight subjects of the EMPIRE-01 trial participated in EMPIRE-02. Twenty adverse events (AEs) were recorded among five individuals during the combined 52 week treatment period of both trials. Whereas one case of chronic hepatitis B was moderate in severity, all other AEs were mild. There were thus no serious AEs or events necessitating discontinuation or suspension of treatment or a reduction in drug dose. Whereas ketoacidosis or marked increases in serum ketone body levels were not observed, the mean body mass of the subjects was decreased slightly after completion of EMPIRE-02. The improvement in mean values of glycemic parameters observed in EMPIRE-01 was not sustained in EMPIRE-02, mostly because of one individual whose parameters deteriorated markedly, likely as a result of nonadherence to diet therapy. The improvement in glycemic parameters was sustained during EMPIRE-02 after exclusion of this subject from analysis. Empagliflozin demonstrated a certain level of safety and efficacy for the treatment of insulin resistance syndrome and lipoatrophic diabetes over 52 weeks, confirming its potential as a therapeutic option.

Incidência de cetose subclínica em vacas leiteiras na região semiárida da Paraíba

Subclinical ketosis (SCK) is one of the main metabolic diseases to occur during the transition period in dairy herds. The aim of this study was to evaluate the localized incidence of SCK in dairy cows in the semi-arid region of the state of Paraíba, Brazil, and to correlate this data with the number of weeks of lactation and the body condition score (BCS). Samples were collected from the coccygeal vein of 257 lactating dairy cows, with a view to determining serum ketone and glucose body levels. Animals that presented serum ketone body levels equal to or greater than 1.2 mmol/dL were considered to have SCK. It was found that 5.45% of the dairy cows presented SCK. The weeks of lactation and the BCS had no influence (P > 0.05) on the levels of serum ketone bodies or glucose of the dairy cows. For serum ketone body levels, 94.55% (243) of the cows remained within the normal limits for metabolites. Most of the cows, 67.70% (174) were within normal serum glucose levels, while 23.35% (60) presented hypoglycaemia, and 8.95% (23) presented hyperglycaemia. The BCS and serum glucose levels are negatively correlated, with a coefficient of -0.1329 (P = 0.0335). No significance was found 0.087 (P = 0.1608) for the correlation between the BCS and serum ketone body levels. The localized incidence of SCK in this study was 5.45% of the total number of cows, with the BCS and number of weeks of lactation having no influence on incidence of the disorder.

Association between Edinburgh Postnatal Depression Scale and Serum Levels of Ketone Bodies and Vitamin D, Thyroid Function, and Iron Metabolism.

Suicide due to postpartum depression is the most common perinatal-related death and is a social concern in Japan. Nutritional deficiencies during pregnancy may contribute to postpartum depression; therefore, we investigated the relationship between postpartum depression and nutritional status during pregnancy and postpartum. We focused specifically on ketone bodies because they are known to protect brain cells. The relationship between the Edinburgh Postnatal Depression Scale (EPDS) scores and the serum levels of ketone bodies and vitamin D, thyroid function, and iron metabolism was examined. Overall, 126 pregnant women were identified for the study, and 99 were eventually included in the analysis. We defined an EPDS score of ≥9 as being positive for postpartum depression, and serum ketone levels were found to be higher in the group with an EPDS score of ≥9 during the second trimester; however, there were no other significant findings. We may be able to predict postpartum depression from a pregnant woman's serum ketone levels in the second trimester. There was a positive correlation between the EPDS scores at 3 days and 1 month postpartum (r = 0.534, p < 0.001). EPDS scores assessed in the early postpartum period may be useful for the timely detection of postpartum depression.

Immunometabolic Reprogramming in Response to HIV Infection Is Not Fully Normalized by Suppressive Antiretroviral Therapy.

Background: HIV infection results in immunometabolic reprogramming. While we are beginning to understand how this metabolic reprogramming regulates the immune response to HIV infection, we do not currently understand the impact of ART on immunometabolism in people with HIV (PWH). Methods: Serum obtained from HIV-infected (n = 278) and geographically matched HIV seronegative control subjects (n = 300) from Rakai Uganda were used in this study. Serum was obtained before and ~2 years following the initiation of ART from HIV-infected individuals. We conducted metabolomics profiling of the serum and focused our analysis on metabolic substrates and pathways assocaited with immunometabolism. Results: HIV infection was associated with metabolic adaptations that implicated hyperactive glycolysis, enhanced formation of lactate, increased activity of the pentose phosphate pathway (PPP), decreased β-oxidation of long-chain fatty acids, increased utilization of medium-chain fatty acids, and enhanced amino acid catabolism. Following ART, serum levels of ketone bodies, carnitine, and amino acid metabolism were normalized, however glycolysis, PPP, lactate production, and β-oxidation of long-chain fatty acids remained abnormal. Conclusion: Our findings suggest that HIV infection is associated with an increased immunometabolic demand that is satisfied through the utilization of alternative energetic substrates, including fatty acids and amino acids. ART alone was insufficient to completely restore this metabolic reprogramming to HIV infection, suggesting that a sustained impairment of immunometabolism may contribute to chronic immune activation and comorbid conditions in virally suppressed PWH.

Systemic Ketone Replacement Does Not Improve Survival or Cancer Cachexia in Mice With Lung Cancer.

Cachexia is a debilitating comorbidity affecting many lung cancer patients. We have previously found that cachectic mice with lung cancer have reduced serum ketone body levels due to low PPARα activity in the liver. Restoring hepatic PPARα activity with fenofibrate increased circulating ketones and delayed muscle and white adipose tissue wasting. We hypothesized that the loss of circulating ketones plays a pathophysiologic role in cachexia and performed two dietary intervention studies to test this hypothesis. In the first study, male and female mice were randomized to consume either a very low carbohydrate, ketogenic diet (KD) or normal chow (NC) after undergoing tumor induction. The KD successfully restored serum ketone levels and decreased blood glucose in cachectic mice but did not improve body weight maintenance or survival. In fact, there was a trend for the KD to worsen survival in male but not in female mice. In the second study, we compounded a ketone ester supplement into the NC diet (KE) and randomized tumor-bearing mice to KE or NC after tumor induction. We confirmed that KE was able to acutely and chronically increase ketone body abundance in the serum compared to NC. However, the restoration of ketones in the circulation was not able to improve body weight maintenance or survival in male or female mice with lung cancer. Finally, we investigated PPARα activity in the liver of mice fed KE and NC and found that animals fed a ketone ester supplement showed a significant increase in mRNA expression of several PPARα targets. These data negate our initial hypothesis and suggest that restoring ketone body availability in the circulation of mice with lung cancer does not alter cachexia development or improve survival, despite increasing hepatic PPARα activity.

Changes in Serum Levels of Ketone Bodies and Human Chorionic Gonadotropin during Pregnancy in Relation to the Neonatal Body Shape: A Retrospective Analysis.

Among the physiological changes occurring during pregnancy, the benefits of morning sickness, which is likely mediated by human chorionic gonadotropin (HCG) and induces serum ketone production, are unclear. We investigated the relationship between serum levels of ketone bodies and HCG in the first, second, and third trimesters and neonatal body shape (i.e., birth weight, length, head circumference, and chest circumference) in 245 pregnant women. Serum levels of 3-hydroxybutyric acid peaked in late-stage compared with early stage pregnancy (27.8 [5.0–821] vs. 42.2 [5.0–1420] μmol/L, median [range], p < 0.001). However, serum levels of ketone bodies and HCG did not correlate with neonatal body shape. When weight loss during pregnancy was used as an index of morning sickness, a higher pre-pregnancy body mass index was associated with greater weight loss. This study is the first to show that serum ketone body levels are maximal in the third trimester of pregnancy. As the elevation of serum ketone bodies in the third trimester is a physiological change, high serum levels of ketone bodies may be beneficial for mothers and children. One of the possible biological benefits of morning sickness is the prevention of diseases that have an increased incidence due to weight gain during pregnancy.

Mouse Strain Differences in Female Mice Fed a Short‐Term Western Diet

Mouse models of diet‐induced obesity are commonly used for studies of metabolic disease. Since sex and strain differences are suggested to influence the results, studies have been generally limited to males of one mouse strain. This limited study population may impact the understanding of the effect of sex and genetic background on metabolic parameters. Therefore, the purpose of this study was to examine potential differences in short‐term feeding of a high fat diet in two popular strains of female mice. Ten‐week‐old, female FVB/N (FVB, n=20) and C57BL/6‐Ncrl (C57, n=20) mice were fed a Western Diet (WD; 40% calories from fat) or standard chow diet (13% calories from fat) for 6 weeks. Body weight was measured at weekly intervals and the Open Field Test (OFT) was administered to assess changes in activity and behavior at baseline and 6 weeks. The OFT consists of a circular arena, where mice were observed for 10 minutes using a video tracking software system to determine distance, speed, and motion. Tissues and blood were harvested after the 6‐week feeding period. Body weights and organ masses (i.e., heart, liver, adipose, and spleen) were significantly greater in FVB‐chow compared to C57‐chow mice. After 6‐weeks of feeding, body weights, adipose mass, and liver mass were significantly higher in FVB‐WD but not in C57‐WD compared to respective chow groups. FVB‐WD had reduced heart weight to tibial length ratios (FVB‐WD: 6.05±0.14 vs. FVB‐chow: 5.41±0.14, P&lt;0.05) and higher serum ketone body levels compared to FVB‐chow (FVB‐WD: 0.42±0.03 vs. FVB‐chow: 0.76±0.15 mM, P&lt;0.05), changes that were not observed in C57‐WD. OFT results revealed significant effects of diet and mouse strain. At baseline, FVB mice spent greater time moving (422± vs. 379±11 sec, P&lt;0.05) and greater time in the border zone (515±9 vs. 452±11 sec, P&lt;0.05) compared to C57 mice. After 6 weeks, time spent moving tended to decrease in C57‐WD compared to C57‐Chow (42% vs. 30%, P&lt;0.10) while FVB‐WD and FVB‐chow had similar decreases (15% vs. 13% in FVB‐chow). Time in the border zone significantly increased by 8% in C57‐WD compared to a 20% decrease in C57‐chow. In contrast, border zone time decreased by 9% and 10% in FVB‐chow and FVB‐WD, respectively. In summary, in response to 6 weeks of WD, female FVB mice exhibit a more pronounced physical phenotype whereas female C57 mice are more prone to changes in activity and behavior. Overall, these results highlight important strain differences in response to a short‐term high fat diet in female mice

Serum ketone body measurement in patients with diabetic ketoacidosis.

Diabetic ketoacidosis (DKA) is a critical manifestation in patients with diabetes mellitus. DKA has been conventionally diagnosed by the presence of hyperglycemia (blood glucose levels > 250mg/dl) and metabolic acidosis (blood gas bicarbonate [HCO3 -] < 18mmol/l and pH in blood gas < 7.30). However, quantitative evaluation of serum ketone bodies has not been established. The current study investigates serum ketone body levels in patients suspected for DKA. We have retrospectively evaluated patients with hyperglycemia whose serum ketone body levels at the outpatient clinic and emergency department were measured simultaneously with blood gas analysis during 2011-2019. Clinical backgrounds, severity of diabetes, serum ketone bodies, and blood gas factors were analyzed. Seventy-two patients were enrolled in the study, after the exclusion of patients who had ketosis due to factors other than diabetes. Serum ketone body levels were negatively correlated with the levels of blood HCO3 - and pH. By receiver-operating-characteristic curve analyses, optimal cut-off values for diagnosis of DKA were determined at 6.3mmol/l of beta-hydroxybutyrate, 1.4mmol/l of acetoacetate, and 8.0mmol/l of total ketone body, respectively. Moreover, serum ketone bodies appeared to effectively differentiate between type 1 and type 2 diabetes mellitus. The cut-off values were higher than those in previous reports. Serum ketone body levels were thought to be useful in the diagnosis of DKA. Further investigations with increased numbers of patients are required to establish the appropriate application of serum ketone bodies in patients with DKA. The online version contains supplementary material available at 10.1007/s13340-022-00581-2.

Murine remote ischemic preconditioning suppresses diabetic ketoacidosis by enhancing glycolysis and entry into tricarboxylic acid cycle in the liver

AimsHindlimb ischemia-reperfusion (IR) was previously demonstrated by our group to decrease blood sugar levels by suppressing hepatic gluconeogenesis and enhancing glucose uptake using activation of the parasympathetic nervous system. While IR attenuated hyperglycemia in diabetic mice, it was unclear whether IR regulated energy metabolism in the liver. We investigated the mechanisms by which IR regulates energy metabolism in the liver from type1 diabetic mice. Main methodsStreptozotocin-induced diabetic male C57BL/6J mice were used to determine the effect of IR on the factors involved in energy metabolism in the liver (i.e., activation levels of AMP-activated protein kinase, aconitase and pyruvate dehydrogenase; adenosine triphosphate and fumarate concentrations; sirtuin (Sirt) 1 expression). These various signaling pathways and key enzyme activities were examined using western blot analysis and a biochemical technique including a colorimetric assay. Key findingsUnder feeding conditions (free access to normal murine chow and water), blood glucose levels and serum ketone body levels were significantly suppressed by IR, whereas phospho-AMP-activated protein kinase and its activity, pyruvate dehydrogenase, aconitase activity, and Sirt 1expression were upregulated. In contrast, peroxisome proliferator-activated receptor γ coactivator-1, which accelerated fatty acid use, was suppressed by IR. SignificanceThese results indicated that in the IR-treated diabetic liver, energy production was promoted through acceleration of the tricarboxylic acid cycle linked with increased glucose preference rather than fatty acid under feeding conditions. Therefore, IR may be beneficial against diabetic hyperglycemia, but also ketoacidosis.

Feasibility, Safety, and Beneficial Effects of MCT-Based Ketogenic Diet for Breast Cancer Treatment: A Randomized Controlled Trial Study

The present study was aimed to evaluate the safety, tolerability, and beneficial effects of a ketogenic diet (KD) on body composition and blood parameters and survival in patients with breast cancer. In this randomized, controlled trial, 60 patients with locally advanced or metastatic breast cancer and planned chemotherapy, were randomly assigned to a group receiving KDs (n = 30) or to a control group with standard diet (n = 30) for 3 months. Serum biochemical parameters and body composition were analyzed at baseline, every 3 weeks and end of each arm. Compliance and safety of KD were also checked weekly. Fasting blood sugar (FBS) was significantly decreased in intervention group compared to the baseline (84.5 ± 11.3 vs. 100.4 ± 11.8, P = 0.001). A significant inter-group difference was also observed for FBS level at end of intervention. There was an increasing trend in serum levels of ketone bodies in intervention group (0.007–0.92, P < 0.001). Compared to the control group, BMI, body weight, and fat% were significantly decreased in intervention group in last visit (P < 0.001). No severe adverse side effect was found regarding lipid profile and kidney or liver marker. Overall survival was higher in KD group compared to the control group in neoadjuvant patients (P = 0.04). Our results suggested that chemotherapy combined with KDs can improve the biochemical parameters, body composition, and overall survival with no substantial side effects in patients with breast cancer.

Investigating the effect of chemotherapy combined with ketogenic diet on stage IV colon cancer.

e15182 Background: The effectiveness of carbohydrate restriction to limiting cancer growth has often been observed in in vitro and in vivo experiments; however, few cases of clinical efficacy have been reported. We examined the clinical effectiveness of chemotherapy with ketogenic diet for advanced cancer treatment. Methods: We administered chemotherapy with a modified medium-chain triglyceride (MCT) ketogenic diet at a ratio of 1.4:1 in 10 patients with stage IV recurrent colon cancer for one year and performed a conversion surgery in five of the cases. We followed-up for the next 3 years, compared the overall survival (OS) of the chemotherapy-only group of the stage IV colon cancer patients, and investigated the factors contributing to an improved OS. Results: Evaluations in the first year revealed a response rate of 21% and disease control rate of 64% for patients in the chemotherapy-only group. Patients in the ketogenic diet-chemotherapy combination group exhibited a response rate of 60%, disease control rate of 70%, and complete response rate of 50% for the five conversion surgeries. The time to conversion surgery was 4.0±0.9 months and the time to postoperative recurrence was 6.2±2.6 months. Regarding the duration of overall survival, there was no significant difference ( p value = 0.98) upon comparing the ketogenic diet group with the chemotherapy-only group (32.5 months and 37.9 months, respectively). However, overall survivals were 50 months, 23.0 months, and 32.5 months for the ketogenic diet-chemotherapy combination response group, ketogenic diet-chemotherapy combination non-response group, and chemotherapy-only group, respectively ( p value = 0.07). The ketogenic diet-chemotherapy combination response group tended to have a longer OS than the chemotherapy-only group. In addition, in the ketogenic diet-chemotherapy combination response group, introduction time was earlier than the ketogenic diet-chemotherapy combination non-response group for 5.7 months, with high serum ketone body levels and low blood sugar levels. Conclusions: Chemotherapy with ketogenic diet resulted in higher response and disease control rates than chemotherapy alone. Additionally, the conversion surgery rate was high and an improved OS could be expected. Therefore, ketogenic diet may be a supportive therapy to chemotherapy. Clinical trial information: 000029527.

Clinical characteristics of anti-glutamic acid decarboxylase antibody-positive fulminant type 1 diabetes.

This research aimed to examine the relationship between anti-glutamic acid decarboxylase antibody (GADA) titers and clinical parameters at onset and to clarify the association between clinical severity and GADA titers in GADA-positive fulminant type 1 diabetes. This cross-sectional observational study included 20 cases with GADA-positive fulminant type 1 diabetes (4 cases from our hospital and 16 from cases reported in the literature). The association between GADA titers and clinical parameters [age, sex, body weight, body mass index, period from appearance of any prodromal symptoms to diagnosis, period from development of hyperglycemic symptoms to diagnosis, GADA titer, HbA1c level, blood pH and HCO3- level, serum levels of ketone bodies and pancreatic exocrine enzymes] were analyzed. Spearman's rank correlation coefficient (rs) was used for the correlation analysis. The results showed that there was a significant inverse correlation between GADA titers and the "period from appearance of any prodromal symptoms to diagnosis" (rs = -0.559, p < 0.05). Moreover, GADA titers were inversely correlated with blood pH and HCO3- level (rs = -0.576, p < 0.05, rs = -0.578, p < 0.05, respectively), and positively correlated with serum levels of total ketone bodies, acetoacetate, and 3-hydroxybutyrate (rs = 0.661, p < 0.05; rs = 0.700, p < 0.05; and rs = 0.782, p < 0.01, respectively). These findings suggest that higher GADA titers may be linked to more severe clinical severity of GADA-positive fulminant type 1 diabetes at onset. This association may be attributed to possible pre-existence of autoimmunity-related β-cell damage before the onset of fulminant type 1 diabetes.

Intra- and inter-subject variability for increases in serum ketone bodies in patients with type 2 diabetes treated with the sodium glucose co-transporter 2 inhibitor canagliflozin.

Sodium glucose co‐transporter 2 (SGLT2) inhibitors have been associated with increased serum ketone body levels in patients with type 2 diabetes mellitus (T2DM). In the present analysis we evaluated serum ketone body levels and variability in 1278 Japanese patients with T2DM treated with canagliflozin 100 or 200 mg. Similar mean increases in ketone body concentrations of ~2‐fold were seen with both canagliflozin doses. The median (interquartile range) percent change from baseline was 62% (0;180) for acetoacetate and 78% (2;236) for β‐hydroxybutyrate. Approximately two‐thirds of the variability in each ketone measure was attributed to intra‐subject variability. Intra‐subject variability was higher for serum ketones than other metabolites. Patients in the lowest response tertile exhibited no increase in ketones. Those in the highest response tertile tended to be male and have higher fasting plasma glucose levels, lower insulin levels, and longer T2DM duration at baseline. Moreover, changes in serum ketones were not fully explained by changes in plasma fatty acids, suggesting downstream effects of SGLT2 inhibition on hepatic metabolism that favour ketogenesis. In summary, increases in serum ketone bodies with canagliflozin were greater and more variable than changes in other metabolic measures in Japanese patients with T2DM.

L-Carnitine enhances exercise endurance capacity by promoting muscle oxidative metabolism in mice

l-Carnitine (LC), the bioactive form of carnitine, has been shown to play a key role in muscle fuel metabolism during exercise, resulting in increased fatty acid oxidation and energy expenditure. However, whether LC contributes to improved endurance exercise performance remains controversial. This study was designed to investigate the effects of LC administration on endurance capacity and energy metabolism in mice during treadmill exercise. Male C57BL/6 mice were divided into two groups (sedentary and exercise) and received daily oral administration of LC (150 mg/kg) or vehicle with a high-fat diet for 3 weeks. During the experimental period, all animals were trained three times a week on a motorized treadmill, and the total running time until exhaustion was used as the index of endurance capacity. LC administration induced a significant increase in maximum running time with a reduction of body fat compared with the control group when mice were subjected to programmed exercise. The serum levels of triglyceride, non-esterified fatty acid, and urea nitrogen were significantly lower in the LC group than the corresponding levels in the control group, while serum ketone body levels were higher in the LC group. Muscle glycogen content of LC administered-mice was higher than that of control mice, concomitant with reduced triglyceride content. Importantly, muscle mRNA and protein expressions revealed enhanced fatty acid uptake and oxidative metabolism and increased mitochondrial biogenesis by LC administration. These results suggest that LC administration promotes fat oxidation and mitochondrial biogenesis while sparing stored glycogen in skeletal muscle during prolonged exercise, resulting in enhanced endurance capacity.

Aging impairs the hepatic subcellular distribution of ChREBP in response to fasting/feeding in rats: Implications on hepatic steatosis

Aging is associated with alterations of lipid metabolism and increased prevalence of non alcoholic hepatic steatosis. Nevertheless, the mechanisms by which fat is accumulated in the liver during aging remain incompletely understood. In the present study, we investigated potential alterations that might contribute to the development of hepatic steatosis with aging. To this end, we analyzed the expression and the subcellular localization of key transcriptional factors involved in lipid metabolism such as ChREBP, Foxo1, Foxa2 and SREBP-1c in the liver of 3- and 24-month old Wistar rats. In addition, we studied the intracellular redistribution of ChREBP in response to fasting/refeeding transition. Old rats were characterized by hepatic steatosis, low serum ketone body levels and postprandial hyperinsulinemia. These observations were paralleled by the cytoplasmic localization and decreased expression of Foxa2, while ChREBP expression was markedly up-regulated and mainly localized in the nucleus. Consequently, the expression of lipogenic and β-oxidation genes was up-regulated or down-regulated, respectively. Besides, the intracellular redistribution of ChREBP in response to fasting/refeeding transition was also impaired in old animals. Additionally, a negative correlation between serum ketone body levels and the nuclear localization of ChREBP was observed only in adult but not in old rats. Taken together, these data suggest that an age-related dysfunctional adaptation of ChREBP, in response to changes in the nutritional state, might contribute to the development of liver steatosis with aging.

BAD-Dependent Regulation of Fuel Metabolism and KATP Channel Activity Confers Resistance to Epileptic Seizures

Neuronal excitation can be substantially modulated by alterations in metabolism, as evident from the anticonvulsant effect of diets that reduce glucose utilization and promote ketone body metabolism. We provide genetic evidence that BAD, a protein with dual functions in apoptosis and glucose metabolism, imparts reciprocal effects on metabolism of glucose and ketone bodies in brain cells. These effects involve phosphoregulation of BAD and are independent of its apoptotic function. BAD modifications that reduce glucose metabolism produce a marked increase in the activity of metabolically sensitive K(ATP) channels in neurons, as well as resistance to behavioral and electrographic seizures in vivo. Seizure resistance is reversed by genetic ablation of the K(ATP) channel, implicating the BAD-K(ATP) axis in metabolic control of neuronal excitation and seizure responses.

Metabonomic Studies of Biochemical Changes in the Serum of Rats by Intratracheally Instilled TiO&lt;SUB&gt;2&lt;/SUB&gt; Nanoparticles

In vivo behavior of nanoparticles and interactions between nanoparticles and organisms are key components of nanotoxicology. In this study, the biochemical compositions of rat serum exposed to TiO2 nanoparticles (nano-TiO2) by intratracheal instillation at low (0.8 mg/kg), medium (4 mg/kg) and high doses (20 mg/kg) were investigated using 1H-NMR techniques with pattern recognition methods. Serum biochemical assays, as well as histopathological and transmission electron microscopy (TEM) examinations of tissues were performed. 1H-NMR spectra and pattern recognition analyses of nano-TiO2 treated animals showed increased serum levels of ketone bodies, choline, low density lipoprotein (LDL), alanine and GLU, and decreased levels of lactate, creatine and pyruvate. Clinical chemistry analyses of serum showed increased levels of lactate dehydrogenase, aspartate aminotransferase, and alkaline phosphatase, as well as increased levels of blood urea nitrogen and creatinine, indicating slight liver and kidney injury. Furthermore, TEM provided an analysis of particle-related structural changes of the lungs, liver and kidneys, and revealed that the localization of nanoparticles within cells induced apoptosis. The damage to the target organs was associated with the perturbation of energy metabolism. Serum 1H-NMR spectra, in combination with pattern recognition techniques, proved to be an efficient and simple metabonomic method to depict the metabolic changes produced by intratracheally-instilled nano-TiO2.

Acid-base analysis of individuals following two weight loss diets

To examine the effects of low-carbohydrate, ketogenic (LCKD) and low-fat (LFD) diets on acid-base status. Prospective analysis of volunteers from two clinical trials. Subset of 39 volunteers from a randomized trial comparing the effects of an LCKD with an LFD, and a single-arm trial of an LCKD. Outpatient research clinic. LCKD (initially <20 g of carbohydrate daily) or LFD (<30% of energy from fat, 500-1000 kcal energy reduction) instruction. Arterial blood gas analysis, serum chemistries (electrolytes, urea nitrogen/creatinine, glucose, ketone bodies, lactate), anion gap, and urine ketone bodies measured at weeks 0, 2, 8, and 24. Participants had a mean (+/-standard deviation) age of 43.5+/-9.3 years; 28 (72%) were female, 29 (74%) were Caucasian. Using linear mixed-model analysis to examine blood test changes from baseline to 24 weeks, the LFD group experienced a decrease in arterial blood pH from a mean of 7.43 at week 0 to 7.40 at week 24 (P=0.03), and the LCKD group experienced a decrease from 7.42 at week 0 to 7.40 at week 24 (P=0.01). The lowest pH measurements observed were 7.34 in the LFD group and 7.37 in the LCKD group. Although serum bicarbonate appeared to decrease from baseline at weeks 2 and 8 in the LCKD group, the change at 24 weeks was not statistically significant in either diet group, and only four of 131 (two of 92 from the LCKD group) measurements were less than 22 mmol/l. The proportion of participants with elevated urine and serum ketone body levels rose in the LCKD group only, was highest at week 2, and decreased over the subsequent time points. In individuals following an LCKD or an LFD, blood pH decreased mildly and the LCKD group experienced a small, transient decrease in serum bicarbonate in conjunction with mild ketosis. This suggests that an LCKD induced a mild compensated metabolic acidosis, but no individual showed evidence of significant metabolic derangement.

A ketogenic diet reduces amyloid beta 40 and 42 in a mouse model of Alzheimer's disease

BackgroundAlzheimer's disease (AD) is a progressive neurodegenerative disorder that primarily strikes the elderly. Studies in both humans and animal models have linked the consumption of cholesterol and saturated fats with amyloid-β (Aβ) deposition and development of AD. Yet, these studies did not examine high fat diets in combination with reduced carbohydrate intake. Here we tested the effect of a high saturated fat/low carbohydrate diet on a transgenic mouse model of AD.ResultsStarting at three months of age, two groups of female transgenic mice carrying the "London" APP mutation (APP/V717I) were fed either, a standard diet (SD) composed of high carbohydrate/low fat chow, or a ketogenic diet (KD) composed of very low carbohydrate/high saturated fat chow for 43 days. Animals fed the KD exhibited greatly elevated serum ketone body levels, as measured by β-hydroxybutyrate (3.85 ± 2.6 mM), compared to SD fed animals (0.29 ± 0.06 mM). In addition, animals fed the KD lost body weight (SD 22.2 ± 0.6 g vs. KD 17.5 ± 1.4 g, p = 0.0067). In contrast to earlier studies, the brief KD feeding regime significantly reduced total brain Aβ levels by approximately 25%. Despite changes in ketone levels, body weight, and Aβ levels, the KD diet did not alter behavioral measures.ConclusionPrevious studies have suggested that diets rich in cholesterol and saturated fats increased the deposition of Aβ and the risk of developing AD. Here we demonstrate that a diet rich in saturated fats and low in carbohydrates can actually reduce levels of Aβ. Therefore, dietary strategies aimed at reducing Aβ levels should take into account interactions of dietary components and the metabolic outcomes, in particular, levels of carbohydrates, total calories, and presence of ketone bodies should be considered.

Elevated hepatocyte levels of the Forkhead box A2 (HNF-3β) transcription factor cause postnatal steatosis and mitochondrial damage

The Forkhead box (Fox) transcription factor Foxa2 (HNF-3β) and related family members Foxa1 (HNF-3α) and Foxa3 (HNF-3γ) act in concert with other hepatocyte nuclear factors (HNF) to coordinately regulate liver-specific gene expression. To circumvent the hepatic functional redundancy of the Foxa proteins, we used the T-77 transgenic (TG) mouse line in which the −3-kb transthyretin (TTR) promoter functioned to increase hepatocyte expression of the Foxa2 cDNA. Adult TG mice exhibited reduced hepatic glycogen and progressive liver injury, but maintained normal serum levels of glucose, insulin, and glucagon. In this study, we further characterized the postnatal liver defect in TTR-FoxA2 TG mice. The postnatal TG mice displayed significant reduction in serum glucose levels and in hepatocyte glycogen storage without increased serum levels of ketone bodies and free fatty acid suggesting that they are not undergoing a starvation response. We show that TG liver developed a substantial transient steatosis, which reached a maximum at postnatal day 5 and is associated with increased expression of hepatic genes involved in fatty acid and triglyceride synthesis, lipid β-oxidation, and amino acid biosynthesis. Furthermore, transmission electron microscopy analysis of postnatal TG liver revealed extensive mitochondrial membrane damage, which is likely due to reactive oxygen species generated from lipid β-oxidation. In conclusion, our model proposes that in response to reduction in hepatocyte glycogen storage, the TTR-Foxa2 TG mice survive by maintaining sufficient serum levels of glucose through gluconeogenesis using deaminated amino acids with dicarboxylate products of peroxisomal lipid β-oxidation shuttled through the tricarboxylic acid cycle. (H epatology 2003;37:1414-1424.)