The hospital and home use of a 30-second hand-held blood ketone meter: guidelines for clinical practice

Clinical significance of an elevated on-admission beta-hydroxybutyrate in acutely ill adult patients without diabetes

OBJECTIVE

To determine the relationship between point-of-care β-hydroxybutyrate (BHB) concentration and outcomes in adult patients without diabetes admitted through ED.

METHODS

This was a prospective study from 10 March to 2 July 2021. Admitted patients without diabetes had capillary BHB sampled in ED. Outcomes of length-of-stay (LOS), composite mortality/ICU admission rates and clinical severity scores (Quick Sepsis Organ Failure Assessment score/National Early Warning Score [qSOFA/NEWS]) were measured. BHB was assessed as a continuous variable and between those with BHB above and equal to 1.0 mmol/L and those below 1.0 mmol/L.

RESULTS

A total of 311 patients were included from 2377 admissions. Median length-of-stay was 4.1 days (IQR 2.1-9.8), 18 (5.8%) died and 37 (11.8%) were admitted to ICU. Median BHB was 0.2 mmol/L (IQR 0.1-0.4). Twenty-five patients had BHB ≥1.0 mmol/L and five were >3.0 mmol/L. There was no significant difference in median LOS for patients with BHB ≥1.0 mmol/L compared to non-ketotic patients, 5.3 days (IQR 2.2-7.5) versus 4.1 days, respectively (IQR 2.0-9.8) (P = 0.69). BHB did not correlate with LOS (Spearman ρ = 0.116, 95% confidence interval: 0.006-0.223). qSOFA and NEWS also did not differ between these cohorts. For those 25 patients with BHB ≥1.0 mmol/L, an infective/inflammatory diagnosis was present in 11 (44%), at least 2 days of fasting in 10 (40%) and ethanol intake >40 g within 48 h in 4 (16%).

CONCLUSIONS

Routine BHB measurement in patients without diabetes does not add to clinical bedside assessment and use should be limited to when required to confirm a clinical impression.

The effectiveness of blood glucose and blood ketone measurement in identifying significant acidosis in diabetic ketoacidosis patients

BACKGROUND

Patients with diabetic ketoacidosis (DKA), a potentially fatal complication of type 1 diabetes, have hyperglycemia, ketonemia and metabolic acidosis. Blood glucose and blood ketone results are often used to triage patients with suspected DKA. This study aimed to establish how effective blood glucose and blood ketone (beta-hydroxybutyrate, BOHB) measurements are in identifying patients with significant acidosis and sought to validate existing diagnostic BOHB thresholds.

METHODS

Initial Emergency Department results on 161 presumptive DKA episodes in 95 patients (42 F, 53 M, age range 14-89 years) containing a complete dataset of D (glucose), K (BOHB) and A (Bicarbonate [HCO3] and pH) results.

RESULTS

Blood glucose correlated poorly with BOHB (r = 0.28 p = 0.0003), pH (r= -0.25, p = 0.002) and HCO3 (r= -0.17, p = 0.04). BOHB, though better, was still limited in predicting pH (r = -0.44, p < 0.0001) and HCO3 (r = -0.49, p < 0.0001). A HCO3 of 18mmol/L equated to a BOHB concentration of 4.3mmol/L, whilst a HCO3 of 15mmol/L equated to a BOHB of 4.7mmol/L. Of the 133 of 161 events with HCO3 < 18mmol/L, 22 were not hyperglycemic (> 13.9mmol/L, n = 8), ketonemic (≤ 3mmol/L, n = 9) or either (n = 5).

CONCLUSIONS

The commonly employed BOHB diagnostic cutoff of 3mmol/L could not be verified. Since acid-base status was poorly predicted by both glucose and BOHB, this highlights that, regardless of their results, pH and/or HCO3 should also be tested in any patient suspected of DKA.

Controversies Around the Measurement of Blood Ketones to Diagnose and Manage Diabetic Ketoacidosis

The measurement of blood ketones in preference to urine ketones has become a well-established tool in the diagnosis and management of diabetic ketoacidosis (DKA). However, there remains considerable disparity between diabetes guidelines regarding if, how, and when this test should be used. While recent guidelines now mainly emphasize blood measurement, several issues nonetheless remain. Many laboratories still measure blood ketones using a semiquantitative test that does not measure the predominant ketone, β-hydroxybutyrate (BOHB), which may hinder patient management. Even when BOHB is measured, the evidence for cutoffs used in DKA diagnosis or exclusion is limited, while its use in gauging severity, treatment progress, and resolution is not fully clear. Lastly, although employing point-of-care meters instead of a laboratory for BOHB measurement brings undoubted benefits, this approach has its own challenges. This article provides a perspective on these topics to complement current recommendations and to suggest how future research may improve its use in the DKA context.

The Eye in Forensic Medicine: A Narrative Review

ABSTRACT

The eye, with its distinctive anatomy, not only reflects a wide variety of diseases in life but also undergoes a myriad of post-mortem changes. Consequently, the eye has long been an area of interest in forensic science, primarily for the estimation of post-mortem interval and therefore the time of death and also for assistance in ascertaining the cause of death. There has been significant progress in the knowledge of ophthalmic forensic science using new technologies which have allowed further possibilities to arise where understanding of this field can assist the forensic pathologist. This review aims to highlight the current knowledge which exists in this field and also to identify important avenues for further investigation. Post-mortem changes of the eye along with its current applications and challenges will be discussed. These include the important areas of post-mortem iris biometrics, pupil size correlation with post-mortem interval, use of point-of-care technology on vitreous humor, and the use of ophthalmic imaging in pediatric abusive head trauma.

Feasibility of Continuous Ketone Monitoring in Subcutaneous Tissue Using a Ketone Sensor

BACKGROUND

The feasibility of measuring β-hydroxybutyrate in ISF using a continuous ketone monitoring (CKM) sensor using a single calibration without further adjustments over 14 days is described.

METHODS

A CKM sensor was developed using wired enzyme technology with β-hydroxybutyrate dehydrogenase chemistry. In vitro characterization of the sensor was performed in phosphate buffered saline at 37°C. In vivo performance was evaluated in 12 healthy participants on low carbohydrate diets, who wore 3 ketone sensors on the back of their upper arms to continuously measure ketone levels over 14 days. Reference capillary ketone measurements were performed using Precision Xtra® test strips at least 8 times a day.

RESULTS

The sensor is stable over 14 days and has a linear response over the 0-8 mM range. The operational stability of the sensor is very good with a 2.1% signal change over 14 days. The first human study of the CKM sensor demonstrated that the sensor can continuously track ketones well through the entire 14 days of wear. The performance with a single retrospective calibration of the sensor showed 82.4% of data pairs within 0.225 mM/20% and 91.4% within 0.3 mM/30% of the capillary ketone reference (presented as mM at <1.5 mM and as percentage at or above 1.5 mM). This suggests that the sensor can be used with a single calibration for the 14 days of use.

CONCLUSIONS

Measuring ketones in ISF using a continuous ketone sensor is feasible. Additional studies are required to evaluate the performance in intended patient populations, including conditions of ketosis and diabetic ketoacidosis.

Glargine versus regular insulin protocol in feline diabetic ketoacidosis

Objectives

To determine whether basal‐bolus administration of glargine insulin is a safe and effective alternative treatment compared to the standard continuous rate infusion (CRI) protocol.

Design

Prospective randomized clinical trial.

Setting

University teaching hospital.

Animals

Twenty cats diagnosed with diabetic ketoacidosis (DKA).

Interventions

The cats were block‐randomized to either a CRI protocol using regular insulin (CRI‐group; n = 10) or a basal‐bolus SC and IM glargine protocol (glargine‐group, n = 10). Baseline blood gases, electrolytes, glucose, and β‐hydroxybutyrate (β‐OHB) concentrations were measured at the time of admission and later at predefined intervals until reaching the primary endpoint of the study, defined as a β‐hydroxybutyrate concentration < 2.55 mmol/L.

Measurements and main results

The main outcome measure was time (h) to resolution of ketonemia. Secondary outcome measures were time until first improvement of hyperglycemia and ketonemia, decrease of glucose to ≤13.9 mmol/L (250 mg/dL), resolution of acidosis, consumption of first meal, and discharge from hospital. Additionally, occurrence of treatment‐associated adverse events and death were compared. Seventeen cats (85%) survived to discharge, with no difference in survival between groups (P = 1.0). Median times to β‐OHB < 2.55 mmol/L were 42 (CRI‐group) and 30 (glargine‐group) hours, respectively (P = 0.114). Median times to first improvement of hyperglycemia (glargine‐group: 2 h; CRI‐group: 6 h; P = 0.018) and until discharge from hospital (glargine‐group: 140 h; CRI‐group: 174 h; P = 0.033) were significantly shorter in the glargine‐group. No significant differences were observed in any other parameter under investigation (P > 0.05).

Conclusions

Basal‐bolus administration of glargine insulin appears to be an effective and safe alternative to the current standard CRI‐protocol for the management of DKA in cats. The positive outcomes and simplicity make it a viable option for the treatment of feline DKA.

Selectivity and Sensitivity of Near-Infrared Spectroscopic Sensing of β-Hydroxybutyrate, Glucose, and Urea in Ternary Aqueous Solutions

The next-generation artificial pancreas is under development with the goal to enhance tight glycemic control for people with type 1 diabetes. Such technology requires the integration of a chemical sensing unit combined with an insulin infusion device controlled by an algorithm capable of autonomous operation. The potential of near-infrared spectroscopic sensing to serve as the chemical sensing unit is explored by demonstrating the ability to quantify multiple metabolic biomarkers from a single near-infrared spectrum. Independent measurements of β-hydroxy-butyrate, glucose, and urea are presented based on analysis of near-infrared spectra collected over the combination spectral range of 5000-4000 cm^-1 for a set of 50 ternary aqueous standard solutions. Spectra are characterized by a 1 μAU root-mean-square (RMS) noise for 100% lines with a resolution of 4 cm^-1 and an optical path length of 1 mm. Calibration models created by the net analyte signal (NAS) and the partial least squares (PLS) methods provide selective measurements for each analyte with standard errors of prediction in the upper micromolar concentration range. The NAS method is used to determine both the selectivity and sensitivity for each analyte and their values are consistent with these standard errors of prediction. The NAS method is also used to characterize the background spectral variance associated with instrumental and environmental variations associated with buffer spectra collected over a multiday period.

Test validation, method comparison and reference range for the measurement of β-hydroxybutyrate in peripheral blood samples

Introduction

The measurement of β-hydroxybutyrate (βOHB) concentrations is a corner stone of the diagnosis of diabetic ketoacidosis and other ketonic states. The aim of this study was to perform a validation of a peripheral blood βOHB assay (Randox) on a Roche cobas c502 analyser and to establish a βOHB reference range for the validated assay.

Materials and methods

Precision, linearity and limit of detection and blank (LoD, LoB) were determined according to Clinical and Laboratory Standards Institute (CLSI) EP05-A3, EP 06-A and EP17-A2 guidelines, using commercial control material and residual patient sample pools. As method comparison, for 190 semi-quantitative measurements of urine ketones we determined the corresponding βOHB blood concentration. The reference range was based on the CLSI C28-A3 guideline, using 304 randomly selected serum samples from population based German National Cohort (GNC) study.

Results

Coefficients of variation for the validated assay ranged from 1.5% for high concentrations (3.1 mmol/L) to 6.5% for low concentrations (0.1 mmol/L). Detection capacity was LoB = 0.011 mmol/L and LoD = 0.037 mmol/L. Linearity of the assay ranged from 0.10 to 3.95 mmol/L. The agreement between the semi-quantitative urine ketone test and the βOHB blood test was moderate (Kappa = 0.66). The obtained 95% serum reference range was estimated as 0.02 to 0.28 mmol/l βOHB.

Conclusions

The Ranbut βOHB assay showed good precision and analytical performance. Our results confirm that βOHB measurement in peripheral blood is indeed a preferable alternative to the semi-quantitative measurement of urine ketones.

β-hydroxybutyrate Impedes the Progression of Alzheimer's Disease and Atherosclerosis in ApoE-Deficient Mice

β-hydroxybutyrate (β-OHB) has been shown to exert an anti-inflammatory activity. Apolipoprotein-E (ApoE) is strongly associated with atherosclerosis and Alzheimer's disease (AD). This study aimed to explore the therapeutic effect of β-OHB in the brain and the aorta of high-fat diet (HFD)-fed ApoE-deficient mice. We found in Apo-E deficient mice that β-OHB attenuated lipid deposition in the choroid plexus (ChP) and decreased amyloid plaque in the substantia nigra pars compacta. We also found decreased CD68-positive macroglia infiltration of the ChP in β-OHB-treated ApoE-deficient mice. β-OHB treatment ameliorated IgG extravasation into the hippocampal region of the brain. In vitro study using ChP mice cell line revealed that β-OHB attenuated oxidized low-density lipoprotein-induced ApoE-specific differentially expressed inflammatory ChP genes. Treatment with β-OHB reduced aortic plaque formation without affecting blood lipid profiles and decreased serum production of resistin, a well-established risk factor for both AD and atherosclerosis. Thus, the current study suggests and describes the therapeutic potential of β-OHB for the treatment of AD and atherosclerosis.

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.

The Significance of an Increased Beta-Hydroxybutyrate at Presentation to the Emergency Department in Patients with Diabetes in the Absence of a Hyperglycemic Emergency

The significance of hyperketonemia in adults with diabetes presenting to the emergency department with acute illness, not due to a diabetic hyperglycemic emergency, has not been well characterized. Adult patients with diabetes presenting to the emergency department who had venous blood gas and beta-hydroxybutyrate levels measured whilst in the emergency department were retrospectively evaluated for the relationship between BHB and clinical outcomes. Over 6 months, 404 patients with diabetes had at least one beta-hydroxybutyrate level measured in the emergency department. There were 23 admissions for diabetic ketoacidosis (DKA) or hyperosmolar state. Of the remainder, 58 patients had a beta-hydroxybutyrate ≥ 1 mmol/L; this group had a higher glucose at presentation (19.0 (8.8) versus 10.4 (9.9) mmol/L), higher HbA1c (8.8 (5.4) versus 8.0 (3.3)%), lower bicarbonate (22.6 (6.2) versus 24.8 (4.7) mmol/L), and higher anion gap (14.8 (6.1) versus 12.6 (4.2)) than had those with BHB < 1 mmol/L. There was no association between the presence of ketosis and the length of stay (4.2 (7.3) versus (3.0) (7.2) days). Acute illness in those with diabetes associated with ketosis in the absence of DKA is associated with worse glycaemic control than in those without ketosis. Ketosis may represent an intermediate state of metabolic dysregulation rather than being associated with a more severe acute illness, as suggested by no relationship between BHB and length of stay.

Evolving Pharmacotherapeutic Strategies for Type 1 Diabetes Mellitus

Despite pharmacotherapeutic advancements in the management of type 1 diabetes mellitus during the past several decades, patients struggle to achieve glycemic goals. Additionally, hypoglycemia, especially in extremes of age, decreases quality of life. The lack of optimal glycemic control and risk for hypoglycemia are multifactorial. Nevertheless, endeavors aiming to develop pharmacotherapeutic options with enhanced pharmacokinetic, pharmacodynamic, and clinical profiles continue. This review article discusses recent ventures in 3 categories of insulin, non-insulin, and glucagon products.

Capillary Blood Ketone Levels as an Indicator of Inadequate Breast Milk Intake in the Early Neonatal Period

OBJECTIVE

To determine the utility of capillary blood ketone levels as an indicator of inadequate intake of breast milk in the early postnatal period.

STUDY DESIGN

Levels of capillary blood beta-hydroxybutyrate (βOHB), the main ketone body in the blood, were measured with a bedside ketone meter in 585 full-term neonates aged 48-95 hours who were breastfed exclusively. Relationships between weight-loss percentage, blood sodium, glucose, pH, partial pressure of carbon dioxide, base-deficit levels, and βOHB levels were investigated. The diagnostic accuracy of βOHB for predicting excessive weight loss (weight loss ≥10% of birth weight) and hypernatremic dehydration (blood sodium level ≥150 mEq/L) was determined.

RESULTS

βOHB levels were correlated positively with weight-loss percentage and blood sodium levels and were correlated negatively with blood glucose levels. The diagnostic accuracy of βOHB was 0.846 (optimal cut off, 1.55 mmol/L; sensitivity, 80.9%, specificity, 74.0%) for predicting excessive weight loss and 0.868 (optimal cut off, 1.85 mmol/L; sensitivity, 94.3%; specificity, 69.9%) for predicting hypernatremic dehydration according to the area under the receiver operating characteristic curve. Multiple logistic analysis revealed that βOHB and weight loss percentage were the only independent predictors of hypernatremic dehydration. Increases in βOHB levels also were associated with worsening metabolic acidosis and hypocapnia.

CONCLUSION

High βOHB levels were associated with inadequate intake of breast milk in the early postnatal period. The use of bedside capillary blood ketone levels may be clinically useful as an indicator of dehydration, energy depletion, and acid-base imbalance in breastfeeding infants in the early postnatal period.

Smartphone-Powered Electrochemical Dongle for Point-of-Care Monitoring of Blood β-Ketone

A smartphone-powered medical dongle as a miniaturized electrochemical analyzer associated with an enzymatic β-hydroxybutyrate test strip for accurate characterization of blood ketone in peripheral whole blood at the point-of-care, which is capable of providing critical guidance for the evaluation and treatment of diabetic ketoacidosis (DK) and diabetic ketosis acid (DKA), is reported. The measured results of blood ketone by the medical dongle were compared with the clinical results from a bulky biochemical analyzer, and the analysis showed good agreement. The proposed medical smartphone-powered dongle was demonstrated to be a very promising platform as a miniaturized electrochemical analyzer for point-of-care monitoring of the critical biochemical parameters such as blood ketone and a good solution for mobile health management.

SGLT2-I in the Hospital Setting: Diabetic Ketoacidosis and Other Benefits and Concerns

PURPOSE OF REVIEW

Sodium-glucose cotransporter 2 (SGLT2) inhibitors are the newest class of antihyperglycemic agents. They are increasingly being prescribed in the outpatient diabetic population. In this review, we examine the risks and benefits of continuation and initiation of SGLT2 inhibitors in the inpatient setting.

RECENT FINDINGS

There are currently no published data regarding safety and efficacy of SGLT2 inhibitor use in the hospital. Outpatient data suggests that SGLT2 inhibitors have low hypoglycemic risk. They also decrease systolic blood pressure and can prevent cardiovascular death. The EMPA-REG study also showed a decrease in admissions for acute decompensated heart failure. There have been increasing cases of diabetic ketoacidosis, and specifically the euglycemic manifestation, associated with SGLT2 inhibitors use. We present two cases of inpatient SGLT2 inhibitor use, one of continuation of outpatient therapy and one of new initiation of therapy. We then discuss potential risks and methods to mitigate these as well as benefits of these medications in the inpatient setting. We cautiously suggest the use of SGLT2 inhibitors in the hospital. However, these must be used judiciously and the practitioner must be aware of euglycemic diabetic ketoacidosis and its risk factors in this population.

Blood Ketones: Measurement, Interpretation, Limitations, and Utility in the Management of Diabetic Ketoacidosis

Diabetic ketoacidosis (DKA) remains a common medical emergency. Over the last few years, new national guidelines have changed the focus in managing the condition from being glucose-centered to ketone-centered. With the advent of advancing technology and the increasing use of hand-held, point-of-care ketone meters, greater emphasis is placed on making treatment decisions based on these readings. Furthermore, recent warnings about euglycemic DKA occurring in people with diabetes using sodium-glucose co-transporter 2 (SGLT-2) inhibitors urge clinicians to inform their patients of this condition and possible testing options. This review describes the reasons for a change in treating DKA, and outlines the benefits and limitations of using ketone readings, in particular highlighting the difference between urine and capillary readings.

Blood versus urine ketone monitoring in a pediatric cohort of patients with type 1 diabetes: a crossover study

BACKGROUND

The aim of our study was to determine the influence of routine ketone monitoring on hyperglycemic events (HE) and ketosis in youngsters with type 1 diabetes (T1D).

METHODS

Our single-site, controlled and randomized study was conducted on children and adolescents with T1D outside of remission phase. During two crossover periods of 6 months, patients (n = 22) experiencing HE tested ketones alternatively with a blood ketone meter or urine ketone test strips and gave their opinion on screening methods after completion of clinical trial. Moreover, we evaluated levels of awareness of ketone production in a series of 58 patients and sometimes parents via a multiple-choice questionnaire.

RESULTS

Based on self-monitoring data, patients experienced a mean of 4.8 HE/month (range 0-9.3). Patients performed accurate ketone tests more frequently during urine (46%) than during blood-testing (29%) periods (p < 0.05); while globally, 50% of ketone tests were inaccurate (i.e. without HE). Ketosis occurred significantly more often during urine (46.4%) than during blood (14.8%) monitoring (p = 0.01), although no episodes of diabetic ketoacidosis (DKA) were noticed. Duration of hyperglycemia was not different whether patients measured ketones or not, suggesting that ketone monitoring did not affect correction of glycemia. Patients evaluated blood monitoring more frequently as being practical, reliable, and useful compared with urine testing. Scores in the awareness questionnaire were globally low (36.8%) without difference between patients and their parents.

CONCLUSIONS

Although our study shows differences in outcomes (e.g. accurate use, detection of ketosis) of urine versus blood ketone monitoring, these did not affect the occurrence of HE. Whereas ketone monitoring is part of standardized diabetes education, its implementation in daily routine remains difficult, partly because patient awareness about mechanisms of ketosis is lacking.

The usefulness of point-of-care (POC) tests in screening elevated glucose and ketone body levels postmortem

The aim was to evaluate the performance of point-of-care (POC) tests in detecting glucose and ketone bodies in postmortem (PM) samples and to assess the usefulness of POC tests in sample screening for more precise analyses. Glucose and ketone body, β-hydroxybutyrate (BHB), were measured from vitreous humor (VH) in 52 autopsy cases with a POC blood glucose monitoring device (BGMD). In addition glucose and ketone bodies, acetone (Ac) and acetoacetate (AcAc), were measured from urine samples in another set of 59 cases with semi-quantitative stick tests. The results were compared to the concentration in VH measured with validated methods (values ≥ 7mmol/l indicate possible hyperglycemia and total ketone body levels ≥ 3mmol/l ketoacidosis). The sensitivity for glucose with the BGMD was 1.0 and specificity 0.94 when the threshold value for the meter to predict elevated glucose was set to ≥ 10mmol/l. The correlation between the BGMD and the validated method was strong (R(2)=0.89). For detecting ketoacidosis, the BGMD had a sensitivity of 1.0 and specificity of 0.73, when the threshold value was set to 2.5mmol/l. The urine stick test presented a sensitivity of 0.89 and specificity of 0.90 for detecting elevated VH glucose concentration. The sensitivity and specificity for the stick test to detect cases with possible ketoacidosis were 0.84 and 0.68, respectively. According to the results, BGMD can be reliably applied for sample screening, although more samples need to be analyzed for delineating the correct threshold values. In the case of glucose, the urine stick tests could be indicative in detecting cases with VH glucose ≥ 10mmol/l. For predicting possible ketoacidosis with elevated VH total ketone bodies, the stick test is not reliable as the test presented both false-positive and -negative results.

Hyperketonemia and ketosis increase the risk of complications in type 1 diabetes

Diets that boost ketone production are increasingly used for treating several neurological disorders. Elevation in ketones in most cases is considered favorable, as they provide energy and are efficient in fueling the body's energy needs. Despite all the benefits from ketones, the above normal elevation in the concentration of ketones in the circulation tend to illicit various pathological complications by activating injurious pathways leading to cellular damage. Recent literature demonstrates a plausible link between elevated levels of circulating ketones and oxidative stress, linking hyperketonemia to innumerable morbid conditions. Ketone bodies are produced by the oxidation of fatty acids in the liver as a source of alternative energy that generally occurs in glucose limiting conditions. Regulation of ketogenesis and ketolysis plays an important role in dictating ketone concentrations in the blood. Hyperketonemia is a condition with elevated blood levels of acetoacetate, 3-β-hydroxybutyrate, and acetone. Several physiological and pathological triggers, such as fasting, ketogenic diet, and diabetes cause an accumulation and elevation of circulating ketones. Complications of the brain, kidney, liver, and microvasculature were found to be elevated in diabetic patients who had elevated ketones compared to those diabetics with normal ketone levels. This review summarizes the mechanisms by which hyperketonemia and ketoacidosis cause an increase in redox imbalance and thereby increase the risk of morbidity and mortality in patients.

Comparing Finger-stick β-Hydroxybutyrate with Dipstick Urine Tests in the Detection of Ketone Bodies

OBJECTIVES

Blood ketone (beta-hydroxybutyrate) measurements are suggested instead of urine ketone (acetoacetate) measurements in the diagnosis of diabetic ketoacidosis. Urine ketone examination is difficult and time consuming, and may result in an incorrect interpretation. Studies performed in emergency departments on blood ketones are limited. Our objective is to compare urine ketones and capillary blood ketones in patients whose serum glucose levels were ≥150 mg/dl.

METHODS

In our cross-sectional prospective study, finger-stick blood beta-hydroxybutyrate, arterial blood gas and urine ketone measurements of patients whose serum glucose levels were 150 mg/dL and higher were performed in the emergency department.

RESULTS

A total of 265 patients were included in the study. The mean age of the patients was 62.4±14.9 years, and 65.7% of them were female. The mean of the capillary blood ketone levels of the patients was determined to be 0.524±0.9 mmol/L (min: 0 mmol/L, max: 6.7 mmol/L). In 29 (13.1%) of the 221 patients whose urine ketone levels were negative, the finger-stick blood ketone levels were positive. Three of these patients were severely ketonemic, six were moderately ketonemic, and 20 were mildly ketonemic.

CONCLUSIONS

In patients admitted to the emergency department with a blood glucose level of 150 mg/dL or higher, performing a capillary blood ketone measurement instead of a urine ketone measurement was a better predictor of ketonemia.

Acetone as biomarker for ketosis buildup capability--a study in healthy individuals under combined high fat and starvation diets

Background

Ketogenic diets are high fat and low carbohydrate or very low carbohydrate diets, which render high production of ketones upon consumption known as nutritional ketosis (NK). Ketosis is also produced during fasting periods, which is known as fasting ketosis (FK). Recently, the combinations of NK and FK, as well as NK alone, have been used as resources for weight loss management and treatment of epilepsy.

Methods

A crossover study design was applied to 11 healthy individuals, who maintained moderately sedentary lifestyle, and consumed three types of diet randomly assigned over a three-week period. All participants completed the diets in a randomized and counterbalanced fashion. Each weekly diet protocol included three phases: Phase 1 - A mixed diet with ratio of fat: (carbohydrate + protein) by mass of 0.18 or the equivalence of 29% energy from fat from Day 1 to Day 5. Phase 2- A mixed or a high-fat diet with ratio of fat: (carbohydrate + protein) by mass of approximately 0.18, 1.63, or 3.80 on Day 6 or the equivalence of 29%, 79%, or 90% energy from fat, respectively. Phase 3 - A fasting diet with no calorie intake on Day 7. Caloric intake from diets on Day 1 to Day 6 was equal to each individual’s energy expenditure. On Day 7, ketone buildup from FK was measured.

Results

A statistically significant effect of Phase 2 (Day 6) diet was found on FK of Day 7, as indicated by repeated analysis of variance (ANOVA), F(2,20) = 6.73, p < 0.0058. Using a Fisher LDS pair-wise comparison, higher significant levels of acetone buildup were found for diets with 79% fat content and 90% fat content vs. 29% fat content (with p = 0.00159**, and 0.04435**, respectively), with no significant difference between diets with 79% fat content and 90% fat content. In addition, independent of the diet, a significantly higher ketone buildup capability of subjects with higher resting energy expenditure (R² = 0.92), and lower body mass index (R² = 0.71) was observed during FK.

Electronic supplementary material

The online version of this article (doi:10.1186/s12937-015-0028-x) contains supplementary material, which is available to authorized users.

Hyperketonemia (acetoacetate) upregulates NADPH oxidase 4 and elevates oxidative stress, ICAM-1, and monocyte adhesivity in endothelial cells

BACKGROUND/AIMS

The incidence of developing microvascular dysfunction is significantly higher in type 1 diabetic (T1D) patients. Hyperketonemia (acetoacetate, β-hydroxybutyrate) is frequently found along with hyperglycemia in T1D. Whether hyperketonemia per se contributes to the excess oxidative stress and cellular injury observed in T1D is not known.

METHODS

HUVEC were treated with ketones in the presence or absence of high glucose for 24 h. NOX4 siRNA was used to specifically knockdown NOX4 expression in HUVEC.

RESULTS

Ketones alone or in combination with high glucose treatment cause a significant increase in oxidative stress, ICAM-1, and monocyte adhesivity to HUVEC. Using an antisense approach, we show that ketone induced increases in ROS, ICAM-1 expression, and monocyte adhesion in endothelial cells were prevented in NOX4 knockdown cells.

CONCLUSION

This study reports that elevated levels of ketones upregulate NOX, contributing to increased oxidative stress, ICAM-1 levels, and cellular dysfunction. This provides a novel biochemical mechanism that elucidates the role of hyperketonemia in the excess cellular injury in T1D. New drugs targeting inhibition of NOX seems promising in preventing higher risk of complications associated with T1D.

Utility of ketone measurement in the prevention, diagnosis and management of diabetic ketoacidosis

Ketone measurement is advocated for the diagnosis of diabetic ketoacidosis and assessment of its severity. Assessing the evidence base for ketone measurement in clinical practice is challenging because multiple methods are available but there is a lack of consensus about which is preferable. Evaluating the utility of ketone measurement is additionally problematic because of variability in the biochemical definition of ketoacidosis internationally and in the proposed thresholds for ketone measures. This has led to conflicting guidance from expert bodies on how ketone measurement should be used in the management of ketoacidosis. The development of point-of-care devices that can reliably measure the capillary blood ketone β-hydroxybutyrate (BOHB) has widened the spectrum of applications of ketone measurement, but whether the evidence base supporting these applications is robust enough to warrant their incorporation into routine clinical practice remains unclear. The imprecision of capillary blood ketone measures at higher values, the lack of availability of routine laboratory-based assays for BOHB and the continued cost-effectiveness of urine ketone assessment prompt further discussion on the role of capillary blood ketone assessment in ketoacidosis. In the present article, we review the various existing methods of ketone measurement, the precision of capillary blood ketone as compared with other measures, its diagnostic accuracy in predicting ketoacidosis and other clinical applications including prevention, assessment of severity and resolution of ketoacidosis.

Specific suppression of insulin sensitivity in growth hormone receptor gene-disrupted (GHR-KO) mice attenuates phenotypic features of slow aging

In addition to their extended lifespans, slow-aging growth hormone receptor/binding protein gene-disrupted (knockout) (GHR-KO) mice are hypoinsulinemic and highly sensitive to the action of insulin. It has been proposed that this insulin sensitivity is important for their longevity and increased healthspan. We tested whether this insulin sensitivity of the GHR-KO mouse is necessary for its retarded aging by abrogating that sensitivity with a transgenic alteration that improves development and secretory function of pancreatic β-cells by expressing Igf-1 under the rat insulin promoter 1 (RIP::IGF-1). The RIP::IGF-1 transgene increased circulating insulin content in GHR-KO mice, and thusly fully normalized their insulin sensitivity, without affecting the proliferation of any non-β-cell cell types. Multiple (nonsurvivorship) longevity-associated physiological and endocrinological characteristics of these mice (namely beneficial blood glucose regulatory control, altered metabolism, and preservation of memory capabilities) were partially or completely normalized, thus supporting the causal role of insulin sensitivity for the decelerated senescence of GHR-KO mice. We conclude that a delayed onset and/or decreased pace of aging can be hormonally regulated.

Accuracy of capillary blood 3-β-hydroxybutyrate determination for the detection and treatment of canine diabetic ketoacidosis

In human medicine, diagnosis of diabetic ketoacidosis (DKA) is usually based on measurement of capillary 3-β-hydroxybutyrate (3-HB) with a hand held ketone sensor. This study was conducted to determine if measurement of capillary 3-HB could be useful for the diagnosis and monitoring of canine DKA. Fifteen dogs with diabetic ketosis and 10 with DKA were evaluated. Paired measurements of 3-HB of capillary and venous blood samples were analysed by the electrochemical sensor and reference method. Use of capillary 3-HB measurement during DKA management was then evaluated through simultaneous measurements of capillary 3-HB, urinary AcAc and venous blood gas analysis. Good agreement between capillary and venous 3-HB measurement was detected by the electrochemical sensor and reference method. Monitoring treatment of DKA revealed a significant correlation between capillary 3-HB and acidosis markers, while no significant correlation was observed between AcAc and acidosis markers. A cut-off value of capillary blood 3-HB >3.8 mmol/L for diagnosis of DKA resulted in 70% and 92% sensitivity and specificity. The electrochemical sensor accurately measures 3-HB concentration in both capillary and venous blood samples, is accurate in diagnosing canine DKA, and appears to reflect the patient's metabolic status during DKA treatment.

Effect of Low Calorie Diet and Controlled Fasting on Insulin Sensitivity and Glucose Metabolism in Obese Patients With Type 1 Diabetes Mellitus

Obesity in T1DM patients is associated with the components of metabolic syndrome. The influence of controlled fasting and low calorie diet (LCD) on insulin sensitivity and glucose metabolism was studied in 14 obese patients with type 1 diabetes mellitus (T1DM) (42.6±9.4 years, BMI 32.4±2.1 kg m−2). Insulin sensitivity in obese T1DM patients was measured using a hyperinsulinemic-euglycemic clamp before fasting, immediately after 7 days of fasting, and after 21 days of LCD. Glucose oxidation and non-oxidative glucose disposal were measured before and during the clamp by indirect calorimetry. In the control group of 13 of non-obese T1DM patients (36.9±13.9 years, BMI 22.6±2.1 kg m−2), only one hyperinsulinemic-euglycemic clamp was performed. Obese T1DM patients lost 6.1±1.1 kg after fasting and maintained reduction in body weight after 21 days of LCD. Fasting transiently reduced insulin-mediated glucose disposal in the clamp (from 9.69±1.48 to 6.78±1.21 mg min−1 kg−1, P<0.001). This was caused by reduced glucose oxidation after the fasting period (from 2.81±0.52 to 0.88±0.98 mg min−1 kg−1, P<0.001). We conclude that one week of fasting transiently decreased insulin-mediated glucose disposal in T1DM patients. This was caused by reduced glucose oxidation.

Type 1 diabetes: current concepts in epidemiology, pathophysiology, clinical care, and research

Type 1 diabetes (T1D) is an autoimmune disease mediated by a combination of genetic and environmental triggers resulting in lymphocytic infiltration of pancreatic islets, destruction of beta cells, and lifelong dependency on exogenous insulin. Although T1D is prevalent (1 in 300) and its incidence is steadily increasing worldwide (3% per year), the exact gene-environment interactions precipitating the disease remain unknown. Living with T1D is challenging for patients, families, and caregivers. Because of the relative paucity of pediatric endocrinologists, general pediatricians and other subspecialists may occasionally be faced with the task of managing diabetes-related complaints. Herein, we provide a comprehensive review of the natural history, pathophysiology, and contemporary management of T1D. In addition, recent advances in T1D research are discussed.

Current concepts and controversies in prevention and treatment of diabetic ketoacidosis in children

Diabetic ketoacidosis (DKA) is caused by absolute or relative lack of insulin. Lack of insulin leads to hyperglycemia, ketonemia, and acidosis. Prevalence of DKA at diagnosis of type 1 diabetes (T1D) varies around the world from 18 % to 84 %. Incidence of recurrent DKA is higher among females, insulin pump users, those with a history of psychiatric or eating disorder, and suboptimal socioeconomic circumstances. DKA is the most common cause of death in children with T1D. Children with DKA should be treated in experienced centers. Initial bolus of 10-20 mL/kg 0.9 % saline is followed by 0.45 %-0.9 % saline infusion. Fluid infusion should precede insulin administration (0.1 U/kg/h) by 1-2 hours. The prevention of DKA at diagnosis of diabetes can be achieved by an intensive community intervention and education of health care providers to raise awareness. Prevention of recurrent DKA requires continuous patient education and access to diabetes programs and telephone services.

Point-of-care β-hydroxybutyrate measurement for the diagnosis of feline diabetic ketoacidaemia

OBJECTIVES

To evaluate accuracy and precision of a hand-held ketone meter measuring β-hydroxybutyrate and to determine its diagnostic performance to rule out ketoacidaemia in diabetic cats.

METHODS

The ketone meter was validated by calculating within-day precision at different β-hydroxybutyrate concentrations and by comparison with a laboratory method. To determine its diagnostic performance to diagnose ketoacidaemia, 217 sets of data (venous blood gas analysis and β-hydroxybutyrate measurements) were retrospectively analysed. Sensitivities and specificities were calculated with the help of receiver-operating characteristic curves.

RESULTS

The ketone meter reliably detected β-hydroxybutyrate at concentrations >0·1 mmol/L and reproducibility was acceptable. Measurements highly correlated with laboratory results (r=0·97; P<0·001), but a significant negative bias was found at high concentrations. A β-hydroxybutyrate concentration of >2·55 mmol/L had a sensitivity of 94% and a specificity of 68% for diagnosing ketoacidaemia. Many cats with high β-hydroxybutyrate concentrations and normal blood pH had an elevated chloride gap suggestive of superimposed hypochloraemic metabolic alkalosis.

CLINICAL SIGNIFICANCE

The commercially available point-of-care ketone meter Precision Xtra is a valid tool to measure β-hydroxybutyrate in diabetic cats. Concentration <2·55 mmol/L enable ketoacidaemia to be excluded and should lead to redirection of differential diagnoses.

Measurement of β-hydroxybutyrate in cats with nonketotic diabetes mellitus, diabetic ketosis, and diabetic ketoacidosis

Diabetic ketoacidosis (DKA) is a life-threatening complication of diabetes mellitus (DM). The standard method of detection of ketone bodies is the dipstick method, which detects semiquantitatively acetoacetate, but not β-hydroxybutyrate (β-HB). The objectives of the current study were to assess the diagnostic utility of β-HB to diagnose diabetic ketosis (DK) and DKA in cats and to establish a cut-off value for the diagnosis of DKA. Sixty-two cats were included in the study. Eleven cats were healthy (group 1); in the remainder of cats (51), a diagnosis of DM was based on hyperglycemia, glucosuria, and increased fructosamine concentrations. Nineteen of 51 cats suffered from nonketotic diabetes mellitus (group 2). In 11 cats, plasma ketone bodies were detected with the dipstick method (diabetic ketosis, group 3). In 21 cats, plasma ketone bodies and metabolic acidosis were present (DKA, group 4). Plasma β-HB was measured in all cats by an enzymatic method (spectrophotometry). A cut-off value for the diagnosis of DKA was calculated based on the receiver operating characteristic curve. In healthy cats, the β-HB concentration ranged from 0 to 0.1 mmol/l; in cats of group 2, from 0 to 0.9 mmol/l (median: 0.1 mmol/l); in cats of group 3, from 0.6 to 6.8 mmol/l (median: 1.7 mmol/l); and in cats of group 4, from 3.8 to 12.2 mmol/l (median: 7.9 mmol/l). A cut-off value of 2.4 mmol/l revealed 100% sensitivity and 87% specificity to diagnose DKA. Beta-hydroxybutyrate is a useful parameter for the diagnosis of diabetic ketosis and DKA in cats.

D-β-hydroxybutyrate is protective in mouse models of Huntington's disease

Abnormalities in mitochondrial function and epigenetic regulation are thought to be instrumental in Huntington's disease (HD), a fatal genetic disorder caused by an expanded polyglutamine track in the protein huntingtin. Given the lack of effective therapies for HD, we sought to assess the neuroprotective properties of the mitochondrial energizing ketone body, D-β-hydroxybutyrate (DβHB), in the 3-nitropropionic acid (3-NP) toxic and the R6/2 genetic model of HD. In mice treated with 3-NP, a complex II inhibitor, infusion of DβHB attenuates motor deficits, striatal lesions, and microgliosis in this model of toxin induced-striatal neurodegeneration. In transgenic R6/2 mice, infusion of DβHB extends life span, attenuates motor deficits, and prevents striatal histone deacetylation. In PC12 cells with inducible expression of mutant huntingtin protein, we further demonstrate that DβHB prevents histone deacetylation via a mechanism independent of its mitochondrial effects and independent of histone deacetylase inhibition. These pre-clinical findings suggest that by simultaneously targeting the mitochondrial and the epigenetic abnormalities associated with mutant huntingtin, DβHB may be a valuable therapeutic agent for HD.

[Capillary beta-hydroxybutyrate determination for monitoring diabetic ketoacidosis]

BACKGROUND AND OBJECTIVE

Diabetic ketoacidosis (DKA) is the most severe acute metabolic complication of type 1 diabetes mellitus. Insulin treatment is commonly guided by plasma glucose levels and changes in venous blood gases, while β-hydroxibutyrate (BHB) levels are rarely measured. The study objective was to evaluate the value of capillary BHB monitoring in the course and resolution of DKA.

PATIENTS AND METHODS

Thirty patients with type 1 diabetes admitted for DKA were enrolled. A standard protocol including monitoring of blood glucose, venous blood gases, semiquantitative ketonuria, and capillary BHB was used. Patients were divided into three groups by time to DKA resolution (group 1:<24 h, group 2: 24-48 h, group 3: >48 h), and BHB results were compared to all other biochemical measurements.

RESULTS

Mean laboratory results upon admission were: blood glucose 415 (standard deviation [SD] 106) mg/dL; bicarbonate 9.6 (SD 1.5) mmol/L; pH 7.13 (SD 0.04); BHB 4.33 (SD 0.48) mmol/L, and ketonuria 3+ in 22 patients and 4+ in 6. BHB correlated well with bicarbonate (r=-0.24139; P=0.0161) and pH (r=-0.56419; P<0.0001). BHB normalized earlier than ketonuria in all cases (group 1: 15.5 vs 18.8 hours P<0.05; group 2: 18.2 vs 23.5 hours P<0.01; group 3: 37.3 vs 41.7 hours P<0.01). Ten percent of patients still had ketonuria when blood ketone levels were already normal (<0.5 mmol/L).

CONCLUSION

BHB measurement is an easy, practical, and reliable monitoring method in DKA and may be used as a parameter to adjust insulin treatment.

Diagnostic accuracy of point-of-care testing for diabetic ketoacidosis at emergency-department triage: {beta}-hydroxybutyrate versus the urine dipstick

OBJECTIVE

In the emergency department, hyperglycemic patients are screened for diabetic ketoacidosis (DKA) via a urine dipstick. In this prospective study, we compared the test characteristics of point-of-care β-hydroxybutyrate (β-OHB) analysis with the urine dipstick.

RESEARCH DESIGN AND METHODS

Emergency-department patients with blood glucose ≥250 mg/dL had urine dipstick, chemistry panel, venous blood gas, and capillary β-OHB measurements. DKA was diagnosed according to American Diabetes Association criteria.

RESULTS

Of 516 hyperglycemic subjects, 54 had DKA. The urine dipstick had a sensitivity of 98.1% (95% CI 90.1-100), a specificity of 35.1% (30.7-39.6), a positive predictive value of 15% (11.5-19.2), and a negative predictive value of 99.4% (96.6-100) for DKA. Using the manufacturer-suggested cutoff of >1.5 mmol/L, β-OHB had a sensitivity of 98.1% (90.1-100), a specificity of 78.6% (74.5-82.2), a positive predictive value of 34.9% (27.3-43), and a negative predictive value of 99.7% (98.5-100) for DKA.

CONCLUSIONS

Point-of-care β-OHB and the urine dipstick are equally sensitive for detecting DKA (98.1%). However, β-OHB is more specific (78.6 vs. 35.1%), offering the potential to significantly reduce unnecessary DKA work-ups among hyperglycemic patients in the emergency department.

The performance of a glucose-ketone meter in the diagnosis of diabetic ketoacidosis in patients with type 2 diabetes in the emergency room

BACKGROUND

Diabetic ketoacidosis (DKA) is a serious metabolic complication. One of its precipitating causes is insulin omission. DKA requires early diagnosis and strict glucose control, which increases the use of glucose meters in the Emergency Room (ER). We aimed to determine the performance of a glucose-ketone meter in the diagnosis of DKA.

METHODS

From 450 type 2 diabetes mellitus insulin-treated patients attending the ER with a capillary glucose level >13.9 mmol/L, 50 patients (26 men and 24 women, mean age 60.2 +/- 8.2 years) had DKA. Capillary glucose and beta-hydroxybutyrate (beta-OHB) were measured with the Precision-Xtra device (Abbott Laboratories, Abingdon, UK). Serum glucose and biochemical parameters were measured on an automatic analyzer; serum beta-OHB was determined using an enzymatic end-point spectrophotometric method. Urine ketones were determined using a semiquantitative assay (Ketodiastix, Bayer Diagnostics, Stoke Poges, Slough, UK).

RESULTS

Serum and capillary beta-OHB values were highly correlated (r = 0.99, P < 0.001), and the mean difference between them was 0.49 mmol/L (95% confidence interval [CI], 0.35-0.95 mmol/L; P = 0.81). Similarly, serum and capillary glucose values were significantly correlated (r = 0.86, P < 0.001), and the mean difference between them was 0.43 mmol/L (95% CI, 0.82-0.93 mmol/L; P = 0.71). Patients with DKA were inadequately treated with insulin and missed clinic appointments: 80% of patients with DKA compared to 20% of patients without DKA. In all cases, DKA was attributed to insulin omission. Capillary ketonemia (beta-OHB >3.0 mmol/L) had the highest performance (sensitivity 99.87%, specificity 92.89%, positive predictive value 92.89%) for the diagnosis of DKA compared with serum ketonemia (sensitivity 90.45%, specificity 88.65%, positive predictive value 87.76%) or ketonuria (sensitivity 89.89%, specificity 52.73%, positive predictive value 41.87%).

CONCLUSIONS

Implementation of measures such as home glucose and ketone monitoring can possibly decrease the number of hospital admissions due to DKA.

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.

Ketone measurements using dipstick methodology in cats with diabetes mellitus

OBJECTIVES

To compare the results of urine and plasma ketone dip test in a group of diabetic cats with possible ketosis or ketoacidosis, using laboratory plasma beta-hydroxybutyrate measurements as the gold standard.

METHODS

According to clinical examinations, plasma beta-hydroxybutyrate measurements and venous blood gas analysis, 54 cats with diabetes mellitus were classified as non-ketotic (n=3), ketotic (n=40) or ketoacidotic (n=11). Plasma and urine acetoacetate concentrations were determined using urine reagent strips.

RESULTS

Although there was a significant positive correlation between blood and urine ketone measurements (r=0.695, P<0.001), the results differed significantly (Z=-3.494, P<0.001). Using the differential positive rates, the best cut-off value to detect cats with ketoacidosis was 1.5 mmol/l for urine and 4 mmol/l for plasma. The sensitivity/specificity was 82/95 per cent for urine and 100/88 per cent for plasma, respectively.

CLINICAL SIGNIFICANCE

The urine and plasma ketone dip tests have a different diagnostic accuracy, and results have to be interpreted differently. Because of its high sensitivity, the plasma ketone dip test performs better than the urine ketone dip test to identify cats with impending or established ketoacidosis.

Bedside detection of urine beta-hydroxybutyrate in diagnosing metabolic acidosis

OBJECTIVES

While critically important, the rapid identification of the etiology of metabolic acidosis (MA) may be labor-intensive and time-consuming. Alcoholic, starvation, and severe diabetic ketoacidosis (AKA, SKA, and DKA, respectively) may produce beta-hydroxybutyrate (BOHB) in marked excess of acetone (ACET) and acetoacetate (AcAc). Unfortunately, current urine dipstick technology poorly detects ACET and cannot measure BOHB. The inability to detect BOHB might delay therapy for ketoacidoses or provoke unnecessary evaluation or empiric treatment of other causes of MA, such as toxic alcohol poisoning. The authors tested the previous assertion that commonly available hydrogen peroxide (H(2)O(2)) would improve BOHB detection. The effectiveness of alkalinization and use of a silver nitrate (AgNO(3)) catalyst was also assessed.

METHODS

Control and urine test specimens containing from 0.5 to 800 mmol/L ACET, AcAc, and BOHB were prepared. Urine specimens were oxidized with H(2)O(2) (3%) 1:9 (H(2)O(2):urine), alkalinized with potassium hydroxide (KOH; 10%), exposed to AgNO(3) sticks, or altered with a combination of these methods in a random fashion. Three emergency physicians (EPs) blinded to the preparation technique evaluated urine dipsticks (Multistix, Bayer Corp.) placed in the specimens for "ketones."

RESULTS

Multistix detected AcAc appropriately; ACET was detected only at high concentrations of >or=600 mmol/L. Multistix failed to measure BOHB at all concentrations tested. H(2)O(2) improved urinary BOHB detection, although not to clinically relevant levels (40 mmol/L). Alkalinization and AgNO(3) sticks did not improve BOHB detection beyond this threshold.

CONCLUSIONS

Addition of H(2)O(2) (3%), alkalinization, or AgNO(3) sticks did not improve clinically meaningful urine BOHB detection. Clinicians should use direct methods to detect BOHB when suspected.

Comparison of capillary blood ketone measurement by electrochemical method and urinary ketone in treatment of diabetic ketosis and ketoacidosis in children

We aimed to compare the recent practical method of capillary beta-hydroxy butyrate (betaOHB) measurement with the widely used urinary ketone measurement in monitoring metabolic status of the patient during treatment of diabetic ketoacidosis (DKA) and diabetic ketosis (DK). Patients with DKA and DK admitted to the hospital were followed with simultaneous measurements of capillary betaOHB by electrochemical method (Medisense Optium, Abbott), and urinary ketone by semi-quantitative method. Blood gases were measured in 2-4 h intervals. Fourteen patients with DKA/DK (7 males and 7 females, age: 9.2 +/- 4.2 years) were included with 50 simultaneous measurements of capillary and urinary ketone. No correlation was detected between urinary ketone and blood pH (P = 0.06) and HCO3 (P = 0.79), whereas a significant negative correlation was found between capillary betaOHB and blood pH (r = -0.41, P < 0.05) and HCO3 (r = -0.35, P < 0.05). Capillary betaOHB and urinary ketone levels did not correlate at the beginning and 3.3 +/- 1.4 h after treatment, but did correlate in the third samples taken 7.8 +/- 2.0 h after treatment (r = 0.8, P < 0.05). Capillary betaOHB levels show good correlation with the degree of acidosis (pH and HCO3). Capillary betaOHB measurement is more sensitive than urinary ketone measurement in reflecting the patient's metabolic status and improvement during treatment.

Hydroxybutyrate near-patient testing to evaluate a new end-point for intravenous insulin therapy in the treatment of diabetic ketoacidosis in children

BACKGROUND

The aim of this study was to assess the clinical application of a near-patient testing (NPT) device for capillary blood hydroxybutyrate (HOB) measurement in evaluating a new end-point for intravenous insulin therapy in the treatment of diabetic ketoacidosis (DKA) in children.

METHODS

Children fulfilling the criteria for DKA were treated according to an integrated care pathway (ICP) with fluid replacement and insulin infusion. We measured capillary HOB hourly by NPT (Abbott Optium meter, analytical range 0-6.0 mmol/L), venous blood gases 4 hourly, and venous HOB 4 hourly by laboratory enzymatic method and tested all urine passed for ketones. Two possible ICP end-points were compared: A, pH > 7.3 followed by two successive NPT HOB measurements <1 mmol/L, and B, pH > 7.3 and urine ketone free (our current end-point).

RESULTS

In 35 patient episodes, the ICP was completed (28 to negative ketonuria) without significant variation. Before treatment, median (range) laboratory HOB was 9.5 mmol/L (4.6-15.70 mmol/L), pH 7.18 (6.98-7.38), and standard bicarbonate 11.5 mmol/L (4.3-18.6 mmol/L). ICP end-point A was reached after 17 h (4-39 h), whereas end-point B was not reached until 28 h (14-64 h) after starting treatment. The median lag was 11 h (1-36 h). For 59 paired venous samples (excluding samples with laboratory HOB >6 mmol/L), the relation between NPT (y) and laboratory (x) HOB was y = 0.92x - 0.05, r(2)= 0.94, mean bias -0.25 mmol/L.

CONCLUSIONS

(i) Serial measurement of NPT HOB allows evaluation of a new, simple, earlier end-point for intravenous insulin therapy. (ii) Agreement between NPT and laboratory HOB was clinically acceptable for HOB levels within the meter's analytical range.

[Blood glucose and ketone monitoring in type 1 diabetic patients in the controlled environment of a summer camp]

INTRODUCTION

Control of blood ketone levels and glycemia is advisable in certain situations in type 1 diabetic children and adolescents. The aims of this study were to assess the relationship between glycemia, ketonemia and ketonuria in children and adolescents in a summer camp under different conditions (fasting, casual hyperglycemia, moderate physical exercise) and to assess the utility of ketonemia determinations in diabetes control during this time.

PATIENTS AND METHODS

There were 47 participants (25 boys and 22 girls), with a mean HbA1c determination prior to enrollment of 7.7 +/- 1.5 %. The mean age was 11.7 +/- 1.8 years and the mean time from onset of diabetes was 3.0 +/- 2.7 years. The mean body mass index was 18.3 +/- 3.9 kg/m2 (SDS -0.16 +/- 0.44), the mean insulin dose was 0.8 +/- 0.4 U/kg/ day, and the number of doses per day was between 2 and 4 (median = 3). Blood glucose and ketones (both measured with the Optium system, Abbott Diabetes Care) and urine ketones (Ketodiastix, Bayer) were determined in different situations. Statistical analysis was performed with the SPSS 11.5 program.

RESULTS

Ketonemia results 45 minutes before and after moderate physical activity showed no significant increase in ketones (0.1 +/- 0.03 vs 0.23 +/- 0.07 mmol/l, ns). Preprandial blood ketone levels of > or = 0.5 mmol/l were found in 17.02 % of participants. Ketonemia was resolved during the first hour in all participants except one, in whom ketonemia resolved in 3 hours. Blood ketones were higher before breakfast than during the rest of the day (0.12 +/- 0.17 vs 0.02 +/- 0.05, p < 0.001). The mean glycemia level with ketosis (beta -HB > or = 0.5 mmol/l) was 174.5 +/- 64.7 mg/dl, a value slightly higher than the overall mean glycemia value (156.87 +/- 87.8 mg/dl). Ketonuria could not be measured in a high percentage of participants due to the difficulty of obtaining samples (between 24.5 % and 58.6 % in the different study groups).

CONCLUSIONS

Measurement of glycemia together with ketonemia in a summer camp allows reliable follow-up of glycemic control to be performed. Ketonemia usually occurred before breakfast in parallel with slightly elevated glycemia, but resolved quickly. Moderate physical activity for 45 minutes does not seem to significantly increase blood ketones if metabolic control is normal. beta -HB is a useful parameter to determine whether moderate physical exercise is advisable or not. The lack of urinary ketone tests due to the difficulties of obtaining a sample can currently be solved by blood ketone measurement.

Correlation between urine ketones (acetoacetate) and capillary blood ketones (3-beta-hydroxybutyrate) in hyperglycaemic patients

AIMS

To facilitate the transition from urine ketones (acetoacetate) to capillary blood ketones (3-beta-hydroxybutyrate), we studied the correlation between these two tests.

METHODS

Retrospective study of all patients with blood glucose greater than or equal to 2.5 g/l on arrival in the Emergency Department. We studied the correlation between urine ketones (Clinitek 50, Bayer) and capillary blood ketones (Optium, Abbott). We then compared the relative risks (RR) of ketoacidosis and hospitalization associated with each of these tests.

RESULTS

In 33 months, 529 adult patients with both urine and blood testing for ketones were enrolled (ketoacidosis 8%, admission rate 49%). Urine ketones scored as +, ++ and +++ corresponded to median capillary blood ketone levels of 0.5 mmol/l (IQR: 0.1-0.9), 0.7 mmol/l (IQR: 0.2-1.8) and 3 mmol/l (IQR: 1.4-5.2), respectively. RRs of ketoacidosis or hospitalization associated with blood ketones greater than or equal to 3 mmol/l were higher than those associated with +++ urine ketones: 74 (95% confidence interval [CI]: 48-88) and 2.9 (95% CI: 2.5-3) versus 31 (95% CI: 18-45) and 2 (95% CI: 1.7-2.1), respectively.

CONCLUSIONS

In hyperglycaemic patients in the Emergency Department, a good correlation was observed between urine ketones and capillary blood ketones for low values, but a poor correlation was observed for high values. Either test can therefore be used to exclude ketosis, but the capillary blood ketones test is more accurate to confirm ketoacidosis.

Exploring the clinical utility of blood ketone levels in the emergency department assessment of paediatric patients

BACKGROUND

Ketonuria (on standard urine testing) is a frequent finding in children presenting to emergency departments. With the advent of hand-held ketone meters, blood ketone levels can now be rapidly quantified.

HYPOTHESIS

Point of care testing (POCT) of blood ketone levels could provide clinically useful information on severity of illness in children and risk of hospital admission.

METHODS

A prospective study using POCT of blood ketone levels in a convenience sample of children <13 years old, with a typical case mix of medical problems.

FINDINGS

186 children were studied. The range of ketone levels varied widely among this study population depending on the presenting complaint. Higher levels were noted in those presenting with anorexia or vomiting and fever. The median ketone level of the total study population was 0.2 (range 0-6.0, interquartile range 0.1-0.9) mmol/l. Ketone levels correlated poorly with discharge destination and duration of admission. However, receiver-operator characteristics for ketones as a predictor of admission were comparable to Pediatric Risk of Admission scores (area under the curve 0.64 and 0.72, respectively) and may represent an independent risk factor for admission. A ketone level >1.2 mmol/l has a positive predictive value of 66.7% for admission. Ketone levels correlated well with decreased oral intake (R2 = 0.25; p<0.001).

CONCLUSIONS

A strong association was found between ketone levels, decreased oral intake and fever. Although ketone levels do not correlate well with more traditional markers of illness severity, they can help to predict the requirement for admission to hospital when interpreted in the context of the presenting illness. They may have applications in both the emergency department and primary care settings. Further prospective testing is required to validate these findings.

Bedside monitoring of blood beta-hydroxybutyrate levels in the management of diabetic ketoacidosis in children

INTRODUCTION

Diabetic ketoacidosis (DKA) affects many children with type 1 diabetes. Insulin treatment of DKA is traditionally guided by changes in the blood glucose levels and blood gases, whereas beta-hydroxybutyrate (beta-OHB)--the main ketoacid causing acidosis--is rarely measured. The purpose of this study was to evaluate if bedside monitoring of blood beta-OHB levels can simplify management of DKA through elimination of superfluous laboratory monitoring.

METHODS

Our emergency department treated 68 children with DKA using a standard protocol with monitoring of venous pH, partial pressure of CO(2) (pCO(2)), bicarbonate, glucose, blood urea nitrogen, and electrolytes (two to 10 time points per patient). Venous beta-OHB levels were measured using the Precision Xtra meter (MediSense/Abbott Diabetes Care, Abbott Park, IL) and, on duplicate batched serum samples, using a reference laboratory method (Cobas Mira Plus; Roche Diagnostics, Indianapolis, IN). Correlations between bedside meter beta-OHB and other parameters were evaluated in a series of general linear models with a time series covariance structure fit using spatial power law.

RESULTS

The bedside meter beta-OHB levels were significantly correlated with pH (r = -0.63; P <0.0001), bicarbonate (r = -0.74; P <0.0001), and pCO(2) (r = -0.55; P <0.0001) at all points of measurement during the treatment (unadjusted Pearson correlations). The pH, bicarbonate, and pCO(2) were entered into separate time series analysis models with treatment duration as a measure of time. The results confirmed that bedside levels of beta-OHB correlated very closely with time-dependent levels of venous pH, bicarbonate, and pCO(2). Good agreement between the two methods of beta-OHB measurement (r = 0.92; P <0.0001) was confirmed using the Bland-Altman plot analysis.

CONCLUSIONS

The Precision Xtra accurately measures blood beta-OHB levels, particularly at lower levels. While the initial measurement of pH and/or bicarbonates is warranted, real-time beta-OHB levels may replace repeat laboratory measurement of these parameters in the management of DKA. Future studies should evaluate safety and cost-effectiveness of such simplified DKA treatment protocol.