Post-exercise ketosis and the glycogen content of liver and muscle in rats on a high carbohydrate diet

Summary Post-exercise ketosis is known to be suppressed by physical training and by a high carbohydrate diet. As a result it has often been presumed, but not proven, that the development of post-exercise ketosis is closely related to the glycogen content of the liver. We therefore studied the effect of 1 h of treadmill running on the blood 3-hydroxybutyrate and liver and muscle glycogen concentrations of carbohydrate-loaded trained (n=72) and untrained rats (n=72). Resting liver and muscle glycogen levels were 25%–30% higher in the trained than in the untrained animals. The resting 3-hydroxybutyrate concentrations of both groups of rats were very low: <0.08 mmol·1⁻¹. Exercise did not significantly influence the blood 3-hydroxybutyrate concentrations of trained rats, but caused a marked post-exercise ketosis (1.40±0.40 mmol·1⁻¹ 1 h after exercise) in the untrained animals, the time-course of which was the approximate inverse of the changes in liver glycogen concentration. Interpreting the results in the light of similar data obtained after a normal and low carbohydrate diet it has been concluded that trained animals probably owe their relative resistance to post-exercise ketosis to their higher liver glycogen concentrations as well as to greater peripheral stores of mobilizable carbohydrate.     

自发酮症起病的糖尿病87例临床特征及分型探讨

目的探讨自发酮症起病的糖尿病的临床特征及分型。方法将2003-01～2004-05南京鼓楼医院收治的自发酮症起病的糖尿病患者(87例)根据自身抗体阳性与否,分为抗体阴性组(67例)及抗体阳性组(1A型糖尿病组)(20例)。抗体阴性的患者依据是否依赖胰岛素治疗,进一步分为胰岛素依赖组(27例)及非胰岛素依赖组(40例)。不同组别的临床特征、生化指标之间进行比较。结果抗体阴性组男性发生率显著高于女性;具明显的家族遗传倾向;起病时体重指数显著高于1型糖尿病组,甘油三酯水平高于其他两组;空腹及餐后2hC肽水平介于2型及1型糖尿病组之间。胰岛素依赖组较胰岛素非依赖组具更强的男性易患性;超重和肥胖患者所占比例较低;酮症程度较重;血糖及空腹C肽水平两组之间差异无显著性;3个月后空腹C肽水平,非胰岛素依赖组显著高于胰岛素依赖组。结论酮症起病的糖尿病依据抗体阳性与否,分为抗体阴性和抗体阳性酮症起病的糖尿病,后者即为1A型糖尿病。抗体阴性酮症起病的糖尿病可依据是否依赖胰岛素治疗,分为酮症起病的2型糖尿病和特发性1型糖尿病(1B型糖尿病)。     

1例2型糖尿病酮症患者合并胰岛素过敏的护理

报告1例2型糖尿病酮症患者合并胰岛素过敏的护理经验。护理要点包括：积极与患者家属沟通,采用综合措施补液和降低血糖,监测血糖、血酮变化;准确实施过敏试验及脱敏治疗,密切观察过敏反应,做好应急准备;做好心理护理、出院指导。补液治疗4 h后,患者血酮下降至0.1 mmol/L,采用胰岛素泵持续皮下输注进行脱敏治疗,入院第4天成功实现赖脯胰岛素脱敏,血糖控制平稳出院。随访3~6个月,未再出现过敏反应,血糖控制良好。     

Dietary fat, ketosis, and seizure resistance in rats on the ketogenic diet

PURPOSE: Fat is the major component of the ketogenic diet (KD), yet no studies have examined whether the type of fat used in the diet can be optimized to provide additional benefits. The purpose of the present experiments was to compare the efficiency of different fats in inducing ketosis and affording seizure resistance. METHODS: The effects of KDs that incorporate lard, butter, medium-chain triglycerides (MCT), or flaxseed oil or a mixture of the latter three fats were examined in rats fed KD for up to 98 days. The maximal electroshock (MES) or pentylenetetrazole (PTZ) threshold tests were used to assess seizure susceptibility in two separate experiments. RESULTS: The rank order of induced ketosis was MCT > mixture > or = flaxseed oil > or = lard = butter > or = control. MES failed to reveal anticonvulsant effects, but the PTZ test indicated that up to 50% of rats fed the KD were seizure protected (p < 0.05). The measures of seizure protection, seizure incidence and score, did not correlate, however, with the level of ketosis in the range of 0. 7-5.2 mmol/L for beta-hydroxybutyrate. In the long-term study, flaxseed oil KD maintained stable ketosis throughout 98 days, whereas ketones declined with lard and butter KD to the control level. CONCLUSIONS: Seizure protection with the versions of the KD did not improve with the higher level of ketosis. The focus of the KD improvement, therefore, is not the achievement of higher ketosis per se but rather designing a diet that provides steady ketosis, exploits advantages of certain fats for neurological development or seizure protection via a nonketogenic mechanism, and is nutritionally balanced.     

A comparison of the ability of a 4:1 ketogenic diet and a 6.3:1 ketogenic diet to elevate seizure thresholds in adult and young rats

PURPOSE: The pentylenetetrazol (PTZ) infusion test was used to compare seizure thresholds in adult and young rats fed either a 4:1 ketogenic diet (KD) or a 6.3:1 KD. We hypothesized that both KDs would significantly elevate seizure thresholds and that the 4:1 KD would serve as a better model of the KD used clinically. METHODS: Ninety adult rats and 75 young rats were placed on one of five experimental diets: (a) a 4:1 KD, (b) a control diet balanced to the 4:1 KD, (c) a 6.3:1 KD, (d) a standard control diet, or (e) an ad libitum standard control diet. All subjects were seizure tested by using the PTZ infusion test. Blood glucose and beta-hydroxybutyrate (beta-OHB) levels were measured. RESULTS: Neither KD elevated absolute "latencies to seizure" in young or adult rats. Similarly, neither KD elevated "threshold doses" in adult rats. In young rats, the 6.3:1 KD, but not the 4:1 KD, significantly elevated threshold doses. The 6.3:1 KD group showed poorer weight gain than the 4:1 KD group when compared with respective controls. The most dramatic discrepancies were seen in young rats. CONCLUSIONS: "Threshold doses" and "latency to seizure" data provided conflicting measures of seizure threshold. This was likely due to the inflation of threshold doses calculated by using the much smaller body weights found in the 6.3:1 KD group. Ultimately, the PTZ infusion test in rats may not be a good preparation to model the anticonvulsant effects of the KD seen clinically, especially when dietary treatments lead to significantly mismatched body weights between the groups.     

Ketosis-prone diabetes mellitus: A phenotype that hospitalists need to understand

Diabetes has been classified mainly into types 1 and 2. Some type 2 diabetes patients, when developing ketosis, have been labeled as having atypical diabetes. Lately, syndromes of ketosis-prone diabetes, primarily in patients who we previously classified as type 2 diabetics, have emerged, and calls are being made to even reclassify diabetes. This mini-review will extensively deal with the historical, molecular, phenotypical, and clinical basis of why ketosis-prone diabetes is different than the traditional principles of type 1 and 2 diabetes and should be classified as such. Clinicians, especially those who are not diabetologists or endocrinologists, as well as hospitalists, intensivists, and primary care providers, will greatly benefit from this review.     

聚乙二醇干扰素治疗慢性丙型肝炎诱发糖尿病酮症1例及文献回顾

目前,聚乙二醇干扰素联合利巴韦林已成为治疗慢性丙型肝炎的标准方案。本文报道1例男性慢性丙型肝炎患者,在使用标准治疗24周时,出现了1型糖尿病及酮症。     

Medium Chain Triglycerides induce mild ketosis and may improve cognition in Alzheimer’s disease. A systematic review and meta-analysis of human studies

Introduction/aimThe brain in Alzheimer’s disease shows glucose hypometabolism but may utilize ketones for energy production. Ketone levels can potentially be boosted through oral intake of Medium Chain Triglycerides (MCTs). The aim of this meta-analysis is to investigate the effect of MCTs on peripheral ketone levels and cognitive performance in patients with mild cognitive impairment and Alzheimer’s disease.MethodsMedline, Scopus and Web of Science were searched for literature up to March 1, 2019. Meta-analyses were performed by implementing continuous random-effects models and outcomes were reported as weighted Mean Differences (MDs) or Standardized Mean Differences (SMDs).ResultsTwelve records (422 participants) were included. Meta-analysis of RCTs showed that, compared with placebo, MCTs elevated beta-hydroxybutyrate [MD = 0.355; 95 % CI (0.286, 0.424), I² = 0 %], showed a trend towards cognitive improvement on ADAS-Cog [MD = −0.539; 95% CI (−1.239, −0.161), I² = 0 %], and significantly improved cognition on a combined measure (ADAS-Cog with MMSE) [SMD = −0.289; 95 % CI (−0.551, −0.027), I² = 0 %].ConclusionsIn this meta-analysis, we demonstrated that MCTs can induce mild ketosis and may improve cognition in patients with mild cognitive impairment and Alzheimer’s disease. However, risk of bias of existing studies necessitates future trials.     

Dietary therapies for epilepsy: future research

Since 1921, dietary therapies have remained valuable options in the treatment of intractable childhood epilepsy. The traditional ketogenic diet has been well demonstrated, including in a recent randomized, controlled trial, as being highly effective. More recent alternative diets such as the medium-chain triglyceride diet, modified Atkins diet, and low-glycemic-index treatment have expanded the use of this modality to more children as well as adults. In this review, we discuss our top 10 most pressing research topics related to the ketogenic diet that warrant future study. As well, two promising ketogenic diet clinical researchers discuss their past and current research to help answer some of these questions.