Glucose and ketone body kinetics in diabetic ketoacidosis

Distinct Roles for Brain and Pancreas in Basal and Postprandial Glucose Homeostasis

The glucose homeostasis system ensures that the circulating glucose level is maintained within narrow physiological limits both in the fasting (or basal) state and following a nutrient challenge. Although glucose homeostasis is traditionally conceptualized as a single overarching system, evidence reviewed here suggests that basal glycemia and glucose tolerance are governed by distinct control systems. Specifically, whereas glucose tolerance appears to be determined largely by interactions between insulin secretion and insulin sensitivity, basal-state glucose homeostasis is predominated by insulin-independent mechanisms governed largely by the brain. In addition to a new perspective on how glucose homeostasis is achieved, this "dual control system" hypothesis offers a feasible and testable explanation for observations that are otherwise difficult to reconcile and sheds new light on the integration of central and peripheral metabolic control mechanisms. The implications of this model for the pathogenesis and treatment of impaired fasting glucose, impaired glucose tolerance, and type 2 diabetes are also discussed.

Methamphetamine use and the risk of diabetic ketoacidosis

Diabetic ketoacidosis (DKA) is a life-threatening condition arising in individuals with insulin-dependent diabetes mellitus, associated with hyperglycaemia and hyperketonaemia. While drugs such as methadone, cocaine and certain prescription medications may precipitate DKA, the potential effect of methamphetamine is unclear. Analysis of autopsy and toxicology case files at Forensic Science SA, Adelaide, South Australia, was therefore undertaken from 1 January to 31 December 2019 of all cases where methamphetamine was detected in post-mortem blood samples. There were 94 cases with 11 diabetics (n = 6 type 1 and n = 5 type 2). Four of the six decedents with type 1 diabetes had lethal DKA (66.7%; age range 30-54 years; average age 44.6 ± 10.5 years; M:F ratio 1:1). This incidence of DKA was higher than that of the general insulin-dependent diabetic population (6%) and also significantly higher than in medico-legal cases (13%; p < 0.05). The clinical and autopsy assessment of insulin-dependent diabetics presenting with DKA should therefore include specific screening for methamphetamine. The increase in both insulin-dependent diabetes and methamphetamine abuse in the community may lead to increases in such cases in medico-legal and health contexts.

Differential Diagnosis of Ketoacidosis in Hyperglycemic Alcoholic Diabetic Patient: Role of Insulin

It is important to differentiate between diabetic ketoacidosis (DKA) and alcoholic ketoacidosis (AKA) in an alcoholic diabetic patient since it has significant management implications. Ketoacidosis in an alcoholic diabetic patient is a diagnostic challenge as both these clinical entities have metabolic acidosis with high anion gap. Most patients with DKA have hyperglycemia. The majority of AKA patients present with normal or low glucose levels; however, AKA may also present with high glucose levels, more so in diabetics. The situation becomes quite perplexing when an alcoholic diabetic patient presents with hyperglycemia since it can be attributed to DKA or AKA.

How to cite this article: Garg SK, Garg P. Differential Diagnosis of Ketoacidosis in Hyperglycemic Alcoholic Diabetic Patient: Role of Insulin. Indian J Crit Care Med 2021; 25(10):1203–1204.

Measuring ketone bodies for the monitoring of pathologic and therapeutic ketosis

BACKGROUND

The ketone bodies β-hydroxybutyrate (BOHB) and acetone are generated as a byproduct of the fat metabolism process. In healthy individuals, ketone body levels are ∼0.1 mM for BOHB and ∼1 part per million for breath acetone (BrAce). These levels can increase dramatically as a consequence of a disease process or when used therapeutically for disease treatment. For example, increased ketone body concentration during weight loss is an indication of elevated fat metabolism. Ketone body measurement is relatively inexpensive and can provide metabolic insights to help guide disease management and optimize weight loss.

METHODS

This review of the literature provides metabolic mechanisms and typical concentration ranges of ketone bodies, which can give new insights into these conditions and rationale for measuring ketone bodies.

RESULTS

Diseases such as heart failure and ketoacidosis can affect caloric intake and macronutrient management, which can elevate BOHB 30-fold and BrAce 1000-fold. Other diseases associated with obesity, such as brain dysfunction, cancer, and diabetes, may cause dysfunction because of an inability to use glucose, excessive reliance on glucose, or poor insulin signaling. Elevating ketone body concentrations (e.g., nutritional ketosis) may improve these conditions by forcing utilization of ketone bodies, in place of glucose, for fuel. During weight loss, monitoring ketone body concentration can demonstrate program compliance and can be used to optimize the weight-loss plan.

CONCLUSIONS

The role of ketone bodies in states of pathologic and therapeutic ketosis indicates that accurate measurement and monitoring of BOHB or BrAce will likely improve disease management. Bariatric surgery is examined as a case study for monitoring both types of ketosis.

100th anniversary of the discovery of insulin perspective: insulin and adipose tissue fatty acid metabolism

Insulin inhibits systemic nonesterified fatty acid (NEFA) flux to a greater degree than glucose or any other metabolite. This remarkable effect is mainly due to insulin-mediated inhibition of intracellular triglyceride (TG) lipolysis in adipose tissues and is essential to prevent diabetic ketoacidosis, but also to limit the potential lipotoxic effects of NEFA in lean tissues that contribute to the development of diabetes complications. Insulin also regulates adipose tissue fatty acid esterification, glycerol and TG synthesis, lipogenesis, and possibly oxidation, contributing to the trapping of dietary fatty acids in the postprandial state. Excess NEFA flux at a given insulin level has been used to define in vivo adipose tissue insulin resistance. Adipose tissue insulin resistance defined in this fashion has been associated with several dysmetabolic features and complications of diabetes, but the mechanistic significance of this concept is not fully understood. This review focusses on the in vivo regulation of adipose tissue fatty acid metabolism by insulin and the mechanistic significance of the current definition of adipose tissue insulin resistance. One hundred years after the discovery of insulin and despite decades of investigations, much is still to be understood about the multifaceted in vivo actions of this hormone on adipose tissue fatty acid metabolism.

Diabetic ketoacidosis: A consensus statement of the Italian Association of Medical Diabetologists (AMD), Italian Society of Diabetology (SID), Italian Society of Endocrinology and Pediatric Diabetoloy (SIEDP)

BACKGROUND AND AIM

Diabetic ketoacidosis (DKA) is a serious medical emergency once considered typical of type 1 diabetes (T1DM), but now reported to occur in type 2 and GDM patients as well. DKA can cause severe complications and even prove fatal. The aim of our study was to review recent international and national guidelines on diagnosis, clinical presentation and treatment of diabetic ketoacidosis, to provide practical clinical recommendations.

METHODS AND RESULTS

Electronic databases (MEDLINE (via PUB Med), Scopus, Cochrane library were searched for relevant literature. Most international and national guidelines indicate the same accurate flow chart to diagnose, to evaluate from clinical and laboratory point of view, and treat diabetic ketoacidosis.

CONCLUSION

Prompt diagnosis, rapid execution of laboratory analysis and correct treatment are imperative to reduce the mortality related to diabetic ketoacidosis. These recommendations are designed to help healthcare professionals reduce the frequency and burden of DKA.

Defining and characterising diabetic ketoacidosis in adults

AIMS

Diabetic ketoacidosis (DKA) remains one of the most frequently encountered diabetes related emergencies, and despite updates in management and increasing standardisation of care, still has an appreciable morbidity and mortality. This review focusses on the pathophysiology and epidemiology of DKA, but also on the importance of having a standardised definition.

METHODS

Relevant data were reviewed where there was available basic science or clinical papers published in peer-reviewed international journals on DKA. These included consensus documents and national or international guidelines.

RESULTS

The prevalence of DKA varies around the world, but part of this could be down to the way the condition is defined. Examples of this difference include the recent studies on sodium glucose co-transporter inhibitors in people with type 1 and type 2 diabetes which have all been associated with increased rates of DKA, but have highlighted how differences in definitions can make comparisons between agents very difficult.

CONCLUSIONS

DKA should only be diagnosed when all three components are present - the 'D', the 'K' and the 'A'. In addition, the definitions used to diagnose DKA should be standardised - in particular for clinical trials.

Diabetic ketoacidosis and hyperosmolar hyperglycemic syndrome: review of acute decompensated diabetes in adult patients

Diabetic ketoacidosis and hyperosmolar hyperglycemic syndrome (HHS) are life threatening complications that occur in patients with diabetes. In addition to timely identification of the precipitating cause, the first step in acute management of these disorders includes aggressive administration of intravenous fluids with appropriate replacement of electrolytes (primarily potassium). In patients with diabetic ketoacidosis, this is always followed by administration of insulin, usually via an intravenous insulin infusion that is continued until resolution of ketonemia, but potentially via the subcutaneous route in mild cases. Careful monitoring by experienced physicians is needed during treatment for diabetic ketoacidosis and HHS. Common pitfalls in management include premature termination of intravenous insulin therapy and insufficient timing or dosing of subcutaneous insulin before discontinuation of intravenous insulin. This review covers recommendations for acute management of diabetic ketoacidosis and HHS, the complications associated with these disorders, and methods for preventing recurrence. It also discusses why many patients who present with these disorders are at high risk for hospital readmissions, early morbidity, and mortality well beyond the acute presentation.

Newer Perspectives of Mechanisms for Euglycemic Diabetic Ketoacidosis

Euglycemic diabetic ketoacidosis (EDKA) was considered a rare condition with its specific definition and precipitating factors. However, with the wide use of sodium glucose cotransporter 2 (SGLT-2) inhibitors, the newest class of antidiabetic agents, EDKA has come back into the spotlight. Relevant cases are increasingly being reported along with insights into the mechanism of EDKA. It seems increasingly clear that EDKA is more common than we used to believe. The SGLT-2 inhibitor-associated EDKA also indicates a necessary review of our previous understanding of "diabetic" ketoacidosis, since the SGLT-2 inhibitor predisposes patients to DKA in a "starvation" way. Actually, there are growing reports about starvation-induced ketoacidosis as well. The previously "exclusive" nomenclature and cognition of these entities need to be reexamined. That the hormonal interactions in DKA may differ from the severity of insulin deficiency also may have served in the scenario of EDKA. The SGLT-2 inhibitors are newly approved in China. The main purpose of this work is to have a better understanding of the situation and update our knowledge with a focus on the pathogenesis of EDKA.

The International Society of Pediatric and Adolescent Diabetes guidelines for management of diabetic ketoacidosis: Do the guidelines need to be modified?

The current version of the International Society of Pediatric and Adolescent Diabetes (ISPAD) guidelines for management of diabetic ketoacidosis (DKA) is largely based on the Lawson Wilkins Pediatric Endocrine Society/European Society of Pediatric Endocrinology (LWPES/ESPE) consensus statement on DKA in children and adolescents published in 2004. This article critically reviews and presents the most pertinent new data published in the past decade, which have implications for diagnosis and management. Four elements of the guidelines warrant modification: (i) The definition of DKA; (ii) insulin therapy; (iii) water and salt replacement; and (iv) blood ß-hydroxybutyrate measurements for the management of DKA.

Diabetic ketoacidosis and hyperglycemic hyperosmolar state

Diabetic ketoacidosis (DKA) and the hyperglycemic hyperosmolar state (HHS) are potentially fatal hyperglycemic crises that occur as acute complications of uncontrolled diabetes mellitus. The authors provide a review of the current epidemiology, precipitating factors, pathogenesis, clinical presentation, evaluation, and treatment of DKA and HHS. The discovery of insulin in 1921 changed the life expectancy of patients with diabetes mellitus dramatically. Today, almost a century later, DKA and HHS remain significant causes of morbidity and mortality across different countries, ages, races, and socioeconomic groups and a significant economic burden for society.

Management of diabetic ketoacidosis

Diabetic ketoacidosis (DKA), a life-threatening complication of diabetes mellitus (DM), occurs more commonly in children with type 1 DM than type 2 DM. Hyperglycemia, metabolic acidosis, ketonemia, dehydration and various electrolyte abnormalities result from a relative or absolute deficiency of insulin with or without an excess of counter-regulatory hormones. Management requires careful replacement of fluid and electrolyte deficits, intravenous administration of insulin, and close monitoring of clinical and biochemical parameters directed towards timely detection of complications, including hypokalemia, hypoglycemia and cerebral edema. Cerebral edema may be life threatening and is managed with fluid restriction, administration of mannitol and ventilatory support as required. Factors precipitating the episode of DKA should be identified and rectified. Following resolution of ketoacidosis, intravenous insulin is transitioned to subcutaneous route, titrating dose to achieve normoglycemia.

True euglycemic diabetic ketoacidosis in a person with type 2 diabetes and Duchenne muscular dystrophy

True euglycemic diabetic ketoacidosis is a rare complication of diabetes. We describe a case of diabetic ketoacidosis in a male with type 2 diabetes and Duchenne muscular dystrophy. He presented with normal plasma glucose as a consequence of starvation, reduced muscle mass and increased body fat.

Prevention of diabetic ketoacidosis and self-monitoring of ketone bodies: an overview

OBJECTIVE

Diabetic ketoacidosis (DKA) is associated with significant morbidity and mortality. Self-monitoring of ketone bodies by diabetes patients can be done using blood or urine. We compared the two self-monitoring methods and summarized recent developments in the epidemiology and management of DKA.

METHODS

MEDLINE and EMBASE were searched for relevant publications addressing the epidemiology, management and prevention of DKA up to 2009. The current, relevant publications, along with the authors' clinical and professional experience, were used to synthesize this narrative review.

FINDINGS

Despite considerable advances in diabetes therapy, key epidemiological figures related to DKA remained nearly unchanged during the last decades at a global level. Prevention of DKA - especially in sick day management - relies on intensive self-monitoring of blood glucose and subsequent, appropriate therapy adjustments. Self-monitoring of ketone bodies during hyperglycemia can provide important, complementary information on the metabolic state. Both methods for self-monitoring of ketone bodies at home are clinically reliable and there is no published evidence favoring one method with respect to DKA prevention.

CONCLUSIONS

DKA is still a severe complication potentially arising during prolonged hyperglycemic episodes with possibly fatal consequences. Education of patients and their social environment to promote frequent testing - especially during sick days - and to lower their glucose levels, as well as to recognize the early symptoms of hyperglycemia and DKA is of paramount importance in preventing the development of severe DKA. Both methods for self-monitoring of ketone bodies are safe and clinically reliable.

Diabetic ketoacidosis in the pediatric ICU

Diabetic ketoacidosis (DKA) is a common, life-threatening complication of diabetes mellitus in children. Central nervous system changes seen in DKA include the altered sensorium seen commonly in DKA and loosely characterized as diabetic coma and the uncommon but worrisome progressively deepening coma caused by cerebral edema, which has both a high morbidity and mortality. This article discusses the assessment and treatment of DKA in the setting of the pediatric ICU.

Can serum beta-hydroxybutyrate be used to diagnose diabetic ketoacidosis?

OBJECTIVE

Current criteria for the diagnosis of diabetic ketoacidosis (DKA) are limited by their nonspecificity (serum bicarbonate [HCO(3)] and pH) and qualitative nature (the presence of ketonemia/ketonuria). The present study was undertaken to determine whether quantitative measurement of a ketone body anion could be used to diagnose DKA.

RESEARCH DESIGN AND METHODS

A retrospective review of records from hospitalized diabetic patients was undertaken to determine the concentration of serum beta-hydroxybutyrate (betaOHB) that corresponds to a HCO(3) level of 18 mEq/l, the threshold value for diagnosis in recently published consensus criteria. Simultaneous admission betaOHB and HCO(3) values were recorded from 466 encounters, 129 in children and 337 in adults.

RESULTS

A HCO(3) level of 18 mEq/l corresponded with betaOHB levels of 3.0 and 3.8 mmol/l in children and adults, respectively. With the use of these threshold betaOHB values to define DKA, there was substantial discordance (approximately > or = 20%) between betaOHB and conventional diagnostic criteria using HCO(3), pH, and glucose. In patients with DKA, there was no correlation between HCO(3) and glucose levels on admission and a significant but weak correlation between betaOHB and glucose levels (P < 0.001).

CONCLUSIONS

Where available, serum betaOHB levels > or = 3.0 and > or = 3.8 mmol/l in children and adults, respectively, in the presence of uncontrolled diabetes can be used to diagnose DKA and may be superior to the serum HCO(3) level for that purpose. The marked variability in the relationship between betaOHB and HCO(3) is probably due to the presence of other acid-base disturbances, especially hyperchloremic, nonanion gap acidosis.

The gastroduodenal branch of the common hepatic vagus regulates voluntary lard intake, fat deposition, and plasma metabolites in streptozotocin-diabetic rats

The common hepatic branch of the vagus nerve negatively regulates lard intake in rats with streptozotocin (STZ)-induced, insulin-dependent diabetes. However, this branch consists of two subbranches: the hepatic branch proper, which serves the liver, and the gastroduodenal branch, which serves the distal stomach, pancreas, and duodenum. The aim of this study was to determine whether the gastroduodenal branch specifically regulates voluntary lard intake. We performed a gastroduodenal branch vagotomy (GV) on nondiabetic, STZ-diabetic, and STZ-diabetic insulin-treated groups of rats and compared them with sham-operated counterparts. All rats had high steady-state corticosterone levels to maximize lard intake. Five days after surgery, all rats were provided with the choice of chow or lard to eat for another 5 days. STZ-diabetes resulted in a reduction in lard intake that was partially rescued by either GV or insulin treatment. Patterns of white adipose tissue (WAT) deposition differed after GV- and insulin-induced lard intake, with subcutaneous WAT increasing exclusively after the former and mesenteric WAT increasing exclusively in the latter. GV also prevented the insulin-induced reduction in the STZ-elevated plasma glucagon, triglycerides, free fatty acids, and total ketone bodies but did not alter the effect of insulin-induced reduction of plasma glucose levels. These data suggest that the gastroduodenal branch of the vagus inhibits lard intake and regulates WAT deposition and plasma metabolite levels in STZ-diabetic rats.

Pediatric diabetic ketoacidosis and hyperglycemic hyperosmolar state

Diabetic ketoacidosis is an important complication of diabetes in children and is the most frequent diabetes-related cause of death in childhood. The pathophysiology of this condition can be viewed as an exaggeration of the normal physiologic mechanisms responsible for maintaining an adequate fuel supply to the brain and other tissues during periods of fasting and physiologic stress. The optimal therapy has been a subject of controversy, particularly because the most frequent serious complication of diabetic ketoacidosis-cerebral edema-and the relationship of this complication to treatment are incompletely understood. In this article, the author reviews the pathophysiology of diabetic ketoacidosis and its complications and presents an evidence-based approach to the management of this condition.

Diabetic ketosis activates lymphomonocyte-inducible nitric oxide synthase

AIMS

Inappropriate production of nitric oxide (NO) may be responsible for the haemodynamic disturbances of diabetic ketoacidosis. We investigated whether this metabolic condition is associated with increased plasma nitrate (the stable oxidation product of NO) levels and NO synthase gene expression in lymphomonocytes.

RESEARCH DESIGN AND METHODS

Plasma nitrate concentrations, lymphomonocyte-inducible nitric oxide synthase (iNOS) gene expression, tumour necrosis factor-alpha (TNF-alpha) and soluble thrombomodulin were measured in 11 Type 1 diabetic patients at baseline, during mild ketosis and after euglycaemia was re-established.

RESULTS

During diabetic ketosis plasma nitrate concentrations were higher (18 (16-21) vs. 9 (7-11) micro mol/l; (95% lower-upper confidence interval) P < 0.05) than at baseline. At baseline lymphomonocyte iNOS mRNA expression and iNOS protein levels were undetectable, but in ketosis both were increased (both at P < 0.0001). After recovery from ketosis, NO3 concentration, iNOS mRNA, and iNOS expression (270 +/- 36%, mean +/- sd) decreased but not significantly. No significant changes were observed in either TNF-alpha or soluble thrombomodulin levels between the three conditions.

CONCLUSIONS

Diabetic ketosis is associated with increased nitrate levels and the activation of iNOS expression in circulating lymphomonocytes, but it does not affect either the proinflammatory cytokine TNF-alpha or a marker of endothelial dysfunction such as thrombomodulin. Our data support the hypothesis that, during diabetic ketosis, alterations in NO homeostasis are present in circulating lymphomonocytes.

Diabetic ketoacidosis and hyperglycemic hyperosmolar nonketotic syndrome

Diabetic ketoacidosis (DKA) and hyperglycemic hyperosmolar nonketotic syndrome (HHNS) are life-threatening acute metabolic complications of diabetes mellitus. Although there are some important differences, the pathophysiology, the presenting clinical challenge, and the treatment of these metabolic derangements are similar. Each of these complications can be seen in type 1 or type 2 diabetes, although DKA is usually seen in patients with type 1 diabetes and HHNS in patients with type 2 disease. The clinical management of these syndromes involves careful evaluation and correction of the metabolic and volume status of the patient, identification and treatment of precipitating and comorbid conditions, a smooth transition to a long-term treatment regimen, and a plan to prevent recurrence.

Effects of long-acting somatostatin analogue (Sandostatin) on manifest diabetic ketoacidosis

Insulin deficiency and counterregulatory hormone excess are the basic process in the development of diabetic ketoacidosis (DKA). Somatostatin, which suppresses the secretion of glucagon and growth hormone, has been known to attenuate the rate of gluconeogesis and ketogenesis in insulin-dependent diabetes mellitus patients. However, the therapeutic efficacy of somatostatin has not been approved to be practical in the treatment of manifest DKA. To examine the additive effect of octreotide, the synthetic long-acting somatostatin analogue SMS 201-995, to conventional treatment of manifest DKA, we compared the correction time of acidosis, ketonuria, and hyperglycemia of patients treated with an intravenous infusion of low-dose insulin (4 units per hour) plus subcutaneous injection of octreotide (50 microg every 6 hours) by low-dose insulin alone. The correction time for hyperglycemia and acidosis did not show any difference between groups (p = 0.089, p = 0.82). However, the time for disappearance of ketonuria of the octreotide-treated group (38.0 +/- 32.0 h) was reduced significantly compared to other group (68.3 +/- 26.0 h) (p = 0.048). These results indicated that the addition of octreotide to conventional treatment of DKA might improve the correction of ketosis, but would not allow more rapid control of acidosis and hyperglycemia in manifest DKA.

Effect of various glucagon/insulin molar ratios on blood ketone body levels in rats by use of osmotic minipumps

The bihormonal control by insulin and glucagon of blood ketone body level was studied. Mixed solutions with various molar ratios of glucagon and insulin (G/I) were subcutaneously infused continuously for five days by use of the osmotic minipump in the normal rats. The concentrations of insulin and glucagon solution were set at the high G/I molar ratio, the moderate G/I molar ratio and the low G/I molar ratio. In addition, the moderate G/I molar ratio group was divided into three sub-groups: low glucagon and low insulin, moderate glucagon and moderate insulin, and high glucagon and high insulin. After five days, the rats were decapitated to measure plasma ketone body, free fatty acid (FFA), glucose, insulin and glucagon. The FFA level was not significantly different among three groups. The glucose level was not different between the high and moderate G/I molar ratio groups, and decreased in the low G/I molar ratio group. 3-beta-hydroxybutyrate (3-OHBA) and acetoacetate (AcAc) levels in the high G/I molar ratio group were elevated, and 3-OHBA level in the low G/I molar ratio group was lowered compared to those in the moderate G/I molar ratio group. Among three moderate G/I molar ratio sub-groups, there was no difference in 3-OHBA and AcAc levels. These results demonstrate that plasma ketone body levels are controlled by the plasma G/I molar ratio.

The changes in arterial keton bodies during upper abdominal surgery

The relationship between the arterial keton body ratio (AKBR: acetoacetate/Beta-hydroxybutyrate) and the plasma hormone activities were studied under a general anesthesia using enflurane group (group G) and a GO + Epidural group (group E) with continuous glucose loading (10 g.hr(-1)) during partial gastrectomy. In both groups, the AKBR increased significantly during the operation. The plasma insulin activity was significantly positively correlated with the AKBR and it was negatively correlated with log (Beta-hydroxybutyrate) in both groups. We could not find any significant difference of the AKBR between group G and group E. Our results indicate that the plasma insulin activity affects the arterial keton body ratio and that the AKBR must be evaluated considering the plasma hormone activity, especially insulin activity during the operation.

The effect of glucose and insulin infusion on the fall of ketone bodies during treatment of diabetic ketoacidosis

During the treatment of diabetic ketoacidosis intravenous glucose is infused when blood glucose has fallen to around 14 mmol l-1. The use of hypertonic (10%) glucose has been recommended in order to hasten the clearance of blood ketone bodies. In a randomized controlled study 17 patients presenting with severe diabetic ketoacidosis were allocated to one of two regimens of intravenous glucose and insulin when blood glucose had fallen to less than 14 mmol l-1. Nine patients were given 5% glucose containing 10 U l-1 insulin and 8 patients received 10% glucose with 40 U l-1 insulin. Fluid was infused at a rate of 250 ml h-1 for 6 h. At the start of the infusions blood glucose had fallen from levels at presentation to 12.8 +/- 1.1 mmol l-1 (mean +/- SE) in the group which subsequently received the low infusion rate and to 13.7 +/- 0.9 mmol l-1 in the subsequent high infusion rate group. With glucose/insulin infusion blood glucose after 6 h was 11.5 +/- 0.9 mmol l-1 (low infusion rate group) and 15.7 +/- 1.3 mmol l-1 (high infusion rate group). This difference between groups at 6 h was significant (p less than 0.05). Over the 6 h of infusion the fall in blood total ketone bodies was significantly greater in the group receiving the higher rate of glucose/insulin infusion (7.34 +/- 0.57 vs 5.18 +/- 0.57 mmol l-1; p less than 0.05). Despite the greater fall in total ketone bodies in this group there was no difference in the improvement in capillary blood pH or bicarbonate.(ABSTRACT TRUNCATED AT 250 WORDS)

Relationship between severity of hyperglycemia and metabolic acidosis in diabetic ketoacidosis

We evaluated 114 hospital admissions for diabetic ketoacidosis (occurring in 78 patients) retrospectively by using the Mayo Clinic medical records system. Initial plasma glucose and serum bicarbonate values were examined by using regression analysis. No correlation was found between these two measurements (r = -0.03). The reason for this dissociation between hyperglycemia and hyperketonemia needs further elucidation, but it may be related to impaired hepatic glucose production in some patients.

Fatty acid induced changes in circulating total and free thyroid hormones: in vivo effects and methodological artefacts

Elevated levels of nonesterified fatty acids (NEFA) are frequently found in acute illnesses, and they may contribute to changes in serum thyroid hormone concentrations in nonthyroidal illnesses (NTI) by displacing protein bound hormones. We therefore examined the effects of low and raised plasma NEFA levels on circulating total and free thyroxine (TT4 and FT4) and triiodothyronine (TT3 and FT3) concentrations, the Free T4 Index (FT4I) and TSH, in a randomized crossover study in 10 normal subjects. Subjects ate either a high carbohydrate breakfast (low NEFA protocol) or a high fat breakfast followed by an iv injection of 1000 u heparin (high NEFA protocol). Possible biological effects of changes in FT4 and FT3 were evaluated by a 200 micrograms iv TRH test. Free T4 and T3 were measured by a direct analogue method (AFT4 and AFT3). In a similar high NEFA study, but without TRH, FT4 was also measured by equilibrium dialysis (DFT4) and a 2-step RIA method (2-step FT4). Acute elevations of plasma NEFA from 0.67 +/- 0.08 mmol/L to a peak of 2.6 +/- 0.54 mmol/L resulted in a prompt reciprocal fall of mean TT4 (-8.7%, p less than 0.01), AFT4 (-30%, p less than 0.005) and TT3 (-11.5%, p less than 0.01) and AFT3 (-16%, p less than 0.005); DFT4 rose significantly from 23.7 +/- 1.9 pmol/L to 33.0 +/- 3.7 pmol/L (+39%, p less than 0.025) and 2-step FT4 rose by 16% (p less than 0.05). TSH levels declined consistently from 3.3 +/- 0.5 mIU/L to 2.6 +/- 0.4 mIU/L (p less than 0.025).(ABSTRACT TRUNCATED AT 250 WORDS)