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

Improving Intravenous and Subcutaneous Insulin Overlap During Treatment of Diabetic Ketoacidosis: A Quality Improvement Project

Objective

To reduce the frequency of insufficient overlap of intravenous (IV) and subcutaneous (SC) insulin during the treatment of diabetic ketoacidosis (DKA) as a quality improvement project.

Patients and Methods

Rates of insufficient IV and SC insulin overlap (< 2-hour overlap, SC insulin given after IV insulin discontinuation, or no SC insulin given after IV insulin discontinuation) were assessed in adults with DKA treated with IV insulin at a large tertiary care referral center in Rochester, Minnesota, from July 1, 2021, to March 15, 2023. After a preintervention analysis period, an electronic medical record-based best practice advisory was introduced to notify hospital providers discontinuing IV insulin if SC long-acting insulin had not been given in the previous 2-6 hours. Demographic characteristics and clinical outcomes before and after intervention were compared.

Results

A total of 352 patient encounters were included (251 in the preintervention phase and 101 in the postintervention phase). The rate of insufficient IV to SC insulin overlap decreased from (88 of 251) 35.1% before intervention to (20 of 101) 19.8% after intervention (P=.005). The rate of posttransition hypoglycemia (<70 mg/dL; to convert to mmol/L, multiply by 0.0259) decreased from (27 of 251) 10.7% to (4 of 101) 4% after intervention (P=.04). Rates of posttransition hyperglycemia (>250 mg/dL), rebound DKA, length of hospital stay, and duration of IV insulin therapy were similar before and after intervention.

Conclusion

Using quality improvement methodology, the rates of insufficient IV to SC insulin overlap during treatment of DKA in a large tertiary care referral center were measured and reduced through an electronic medical record-based best practice advisory targeting hospital providers.

Mechanisms and physiological relevance of acid-base exchange in functional units of the kidney

This review discusses the importance of homeostasis with a particular emphasis on the acid-base (AB) balance, a crucial aspect of pH regulation in living systems. Two primary organ systems correct deviations from the standard pH balance: the respiratory system via gas exchange and the kidneys via proton/bicarbonate secretion and reabsorption. Focusing on kidney functions, we describe the complexity of renal architecture and its challenges for experimental research. We address specific roles of different nephron segments (the proximal convoluted tubule, the loop of Henle and the distal convoluted tubule) in pH homeostasis, while explaining the physiological significance of ion exchange processes maintained by the kidneys, particularly the role of bicarbonate ions (HCO3-) as an essential buffer system of the body. The review will be of interest to researchers in the fields of physiology, biochemistry and molecular biology, which builds a strong foundation and critically evaluates existing studies. Our review helps identify the gaps of knowledge by thoroughly understanding the existing literature related to kidney acid-base homeostasis.

Does Treatment with Sodium-Glucose Cotransporter-2 Inhibitors Affect Adherence to International Society Criteria for Diabetic Ketoacidosis in Adult Patients with Type 2 Diabetes? A Retrospective Cohort Analysis

Design

Retrospective observational study. Setting. Inpatients at two teaching hospitals in Queensland, Australia. Primary Outcome Measure(s). The number of patients meeting the Joint British Diabetes Society (JBDS) and American Association of Clinical Endocrinology/American College of Endocrinology (AACE/ACE) diagnostic criteria for DKA. Patients were divided into two groups by treatment with SGLT2i at the time of diagnosis. Participants. Adult patients (>18 years old) with type 2 diabetes diagnosed with DKA from April 2015 to January 2022. Patients without type 2 diabetes were excluded.

Results

One hundred and sixty-five patients were included in this study-comprising 94 patients in the SGLT2i cohort and 70 in the non-SGLT2i cohort. A significantly smaller proportion of patients in the SGLT2i vs. non-SGLT2i cohorts met both JBDS (56% vs. 72%, p = 0.035) and AACE/ACE (63% vs. 82%, p = 0.009) criteria for diagnosis of DKA.

Conclusion

Patients with type 2 diabetes treated with SGLT2i may be more likely to be diagnosed with DKA despite not meeting the criteria. Despite recent adjustments to account the physiological effects of SGLT2i, significant variation in criteria between major society guidelines presents ongoing challenges to clinicians. The proportion of patients diagnosed using both JDBS and AACE/ACE were comparable, suggesting a reasonable degree of agreement.

Pathology of Ketoacidosis in Emergency of Diabetic Ketoacidosis and Alcoholic Ketoacidosis: A Retrospective Study

This study is aimed at examining which factors are useful for the diagnosis and distinction of ketoacidosis. We recruited 21 diabetic ketoacidosis (DKA) and alcoholic ketoacidosis (AKA) patients hospitalized in Kawasaki Medical School General Medical Center from April 2015 to March 2021. Almost all patients in this study were brought to the emergency room in a coma and hospitalized. All patients underwent blood gas aspiration and laboratory tests. We evaluated the difference in diagnosis markers in emergencies between DKA and alcoholic ketoacidosis AKA. Compared to AKA patients, DKA patients had statistically higher values of serum acetoacetic acid and lower values of serum lactate, arterial blood pH, and base excess. In contrast, total ketone bodies, β-hydroxybutyric acid, and β-hydroxybutyric acid/acetoacetic acid ratio in serum did not differ between the two patient groups. It was shown that evaluation of each pathology such as low body weight, diabetes, liver dysfunction, and dehydration was important. It is important to perform differential diagnosis for taking medical histories such as insulin deficiency, alcohol abuse, or starvation as the etiology in Japanese subjects with DKA or AKA. Moreover, it is important to precisely comprehend the pathology of dehydration and alcoholic metabolism which would lead to appropriate treatment for DKA and AKA.

A new turn-on fluorescent probe for fast detection of diabetic biomarker beta-hydroxybutyrate in vitro

Beta-hydroxybutyrate (β-HB) serve as a valuable diagnostic biomarker for Diabetic Ketoacidosis (DKA). Here, a new Schiff base fluorescent probe T was designed and synthesized to detect β-HB level in aqueous solution in vitro. The probe T can detect β-HB sensitively and selectively in DMF solution (5.0 × 10-5 M) among other interfering species (cations, anions, amino acids, biomarkers). The detection limit of probe T for β-HB was calculated to be 0.154 μM. These results demonstrate that the probe T may provide a convenient method for rapid detection of β-HB to diagnose diabetic ketoacidosis.

Ketone production and excretion even during mild hyperglycemia and the impact of sodium-glucose co-transporter inhibition in type 1 diabetes

AIMS

We aimed to determine if ketone production and excretion are increased even at mild fasting hyperglycemia in type 1 diabetes (T1D) and if these are modified by ketoacidosis risk factors, including sodium-glucose co-transporter inhibition (SGLTi) and female sex.

METHODS

In secondary analysis of an 8-week single-arm open-label trial of empagliflozin (NCT01392560) we evaluated ketone concentrations during extended fasting and clamped euglycemia (4-6 mmol/L) and mild hyperglycemia (9-11 mmol/L) prior to and after treatment. Plasma and urine beta-hydroxybutyrate (BHB) concentrations and fractional excretion were analyzed by metabolomic analysis.

RESULTS

Forty participants (50 % female), aged 24 ± 5 years, HbA1c 8.0 ± 0.9 % (64 ± 0.08 mmol/mol) with T1D duration of 17.5 ± 7 years, were studied. Increased BHB production even during mild hyperglycemia (median urine 6.3[3.5-13.6] vs. 3.5[2.2-7.0] µmol/mmol creatinine during euglycemia, p < 0.001) was compensated by increased fractional excretion (0.9 % [0.3-1.6] vs. 0.4 % [0.2-0.9], p < 0.001). SGLTi increased production and attenuated the increased BHB fractional excretion (decreased to 0.3 % during mild hyperglycemia, p < 0.001), resulting in higher plasma concentrations (increased to 0.21 [0.05-0.40] mmol/L, p < 0.001), particularly in females (interaction p < 0.001).

CONCLUSIONS

Even mild hyperglycemia is associated with greater ketone production, compensated by urinary excretion, in T1D. However, SGLTi exaggerates production and partially reduces compensatory excretion, particularly in women.

Point-of-Care Capillary Blood Ketone Measurements and the Prediction of Future Ketoacidosis Risk in Type 1 Diabetes

OBJECTIVE

Rather than during illness while diabetic ketoacidosis (DKA) is developing, we aimed to determine if levels of routine point-of-care capillary blood ketones could predict future DKA.

RESEARCH DESIGN AND METHODS

We examined previously collected data from placebo-assigned participants in an adjunct-to-insulin medication trial program that included measurement of fasted capillary blood ketone levels twice per week in a 2-month baseline period. The outcome was 6- to 12-month trial-adjudicated DKA.

RESULTS

DKA events occurred in 12 of 484 participants at a median of 105 (interquartile range 43, 199) days. Maximum ketone levels were higher in patient cases compared with in control patients (0.8 [0.6, 1.2] vs. 0.3 [0.2, 0.7] mmol/L; P = 0.002), with a nonparametric area under the receiver operating characteristic curve of 0.77 (95% CI 0.66-0.88). Ketone levels ≥0.8 mmol/L had a sensitivity of 64%, a specificity of 78%, and positive and negative likelihood ratios of 2.9 and 0.5, respectively.

CONCLUSIONS

This proof of concept that routine capillary ketone surveillance can identify individuals at high risk of future DKA implies a role for future technologies including continuous ketone monitoring.

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.

Ketone body 3-hydroxybutyrate elevates cardiac output through peripheral vasorelaxation and enhanced cardiac contractility

The ketone body 3-hydroxybutyrate (3-OHB) increases cardiac output and myocardial perfusion without affecting blood pressure in humans, but the cardiovascular sites of action remain obscure. Here, we test the hypothesis in rats that 3-OHB acts directly on the heart to increase cardiac contractility and directly on blood vessels to lower systemic vascular resistance. We investigate effects of 3-OHB on (a) in vivo hemodynamics using echocardiography and invasive blood pressure measurements, (b) isolated perfused hearts in Langendorff systems, and (c) isolated arteries and veins in isometric myographs. We compare Na-3-OHB to equimolar NaCl added to physiological buffers or injection solutions. At plasma concentrations of 2-4 mM in vivo, 3-OHB increases cardiac output (by 28.3±7.8%), stroke volume (by 22.4±6.0%), left ventricular ejection fraction (by 13.3±4.6%), and arterial dP/dtmax (by 31.9±11.2%) and lowers systemic vascular resistance (by 30.6±11.2%) without substantially affecting heart rate or blood pressure. Applied to isolated perfused hearts at 3-10 mM, 3-OHB increases left ventricular developed pressure by up to 26.3±7.4 mmHg and coronary perfusion by up to 20.2±9.5%. Beginning at 1-3 mM, 3-OHB relaxes isolated coronary (EC50=12.4 mM), cerebral, femoral, mesenteric, and renal arteries as well as brachial, femoral, and mesenteric veins by up to 60% of pre-contraction within the pathophysiological concentration range. Of the two enantiomers that constitute racemic 3-OHB, D-3-OHB dominates endogenously; but tested separately, the enantiomers induce similar vasorelaxation. We conclude that increased cardiac contractility and generalized systemic vasorelaxation can explain the elevated cardiac output during 3-OHB administration. These actions strengthen the therapeutic rationale for 3-OHB in heart failure management.

What is the utility of blood beta-hydroxybutyrate measurements in emergency department in patients without diabetes: a systematic review

BACKGROUND

Ketones are synthesised as an alternative fuel source during times of energy restriction. In the absence of a hyperglycemic emergency, ketosis in patients presenting to the emergency department (ED) may indicate reduced carbohydrate intake. In the perioperative setting, excess fasting with ketosis is associated with worse outcomes; however, whether ketosis in patients without diabetes presenting to ED is also associated with worse outcomes is unclear. This systematic review aims to examine the evidence for ketosis in predicting the need for hospital admission in patients without diabetes, presenting to the ED.

METHODS

A systematic review was performed using PRISMA guidelines. We searched electronic bases (OVID-Medline, OVID-EMBASE, Scopus and PubMed) up to December 2022. Eligible studies included children or adults without diabetes presenting to the ED where a point-of-care capillary beta-hydroxybutyrate (BHB) was measured and compared to outcomes including the need for admission. Outcome measures included need for admission and length of stay. Content analysis was performed systematically; bias and certainty assessed using standard tools.

RESULTS

The literature search found 17,133 citations, 14,965 papers were subjected to title and abstract screening. The full text of 62 eligible studies were reviewed. Seven articles met the inclusion criteria. Six studies were conducted solely in the paediatric population, and of these, four were limited to children presenting with gastroenteritis symptoms. Median BHB was higher in children requiring hospital admission with an AUC of 0.64-0.65 across two studies. There was a weak correlation between BHB and dehydration score or duration of symptoms. The single study in adults, limited to stroke presentations, observed no relationship between BHB and neurological deficit at presentation. All studies were at risk of bias using the Newcastle-Ottawa Scale and was assessed of "very low" to "low" quality due to their study design in the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach. Heterogeneity amongst selected studies precluded meta-analysis.

CONCLUSION

The evidence for any utility of BHB measurement in the ED in absence of diabetes is limited to the paediatric population, specifically children presenting with symptoms of gastroenteritis. Any role in adults remains unexplored.

Diabetic Ketoalkalosis: A Common Yet Easily Overlooked Alkalemic Variant of Diabetic Ketoacidosis Associated with Mixed Acid-Base Disorders

BACKGROUND

Diabetic ketoacidosis (DKA) is commonly complicated by mixed acid-base disorders. Therefore, patients with DKA can present with pH > 7.3 or bicarbonate > 18 mmol/L, which falls outside the values defined by the current traditional DKA criteria (pH ≤ 7.3 or bicarbonate ≤ 18 mmol/L).

OBJECTIVE

We aimed to study the spectrum of acid-base clinical presentations of DKA and the prevalence of diabetic ketoalkalosis.

METHODS

This study included all adult patients at a single institution admitted in 2018-2020 with diabetes, positive beta-hydroxybutyric acid, and increased anion gap ≥ 16 mmol/L. Mixed acid-base disorders were analyzed to determine the spectrum of presentation of DKA.

RESULTS

There were 259 encounters identified under the inclusion criteria. Acid-base analysis was available in 227 cases. Traditional acidemic DKA (pH ≤ 7.3), DKA with mild acidemia (7.3 < pH ≤ 7.4), and diabetic ketoalkalosis (pH > 7.4) account for 48.9% (111/227), 27.8% (63/227), and 23.3% (53/227) of cases, respectively. Of the 53 cases with diabetic ketoalkalosis, increased anion gap metabolic acidosis was present in all, and concurrent metabolic alkalosis, respiratory alkalosis, and respiratory acidosis were present in 47.2% (25/53), 81.1% (43/53), and 11.3% (6/53) encounters, respectively. In addition, 34.0% (18/53) of those with diabetic ketoalkalosis were found to have severe ketoacidosis, defined by beta-hydroxybutyric acid ≥ 3 mmol/L.

CONCLUSIONS

DKA can present as traditional acidemic DKA, DKA with mild acidemia, and diabetic ketoalkalosis. Diabetic ketoalkalosis is a common yet easily overlooked alkalemic variant of DKA associated with mixed acid-base disorders, and a high proportion of these presentations have severe ketoacidosis and thus, require the same treatment as traditional DKA.

A rare case report of combined metformin-associated lactic acidosis and diabetic ketoacidosis

Background

Triad of diabetic ketoacidosis (DKA) comprises of hyperglycemia with serum glucose > 11 mmol/L, high anion gap metabolic acidosis and ketonemia. Hyperlactemia is often noted in patients with DKA. Metformin use is one of the risk factors of hyperlactemia, resulting in high anion gap metabolic acidosis, known as metformin associated lactic acidosis (MALA). This report is of a 60-year-old woman with type 2 diabetes mellitus who presented with combined metformin-associated lactic acidosis MALA and DKA.

Case presentation

A 60-year-old diabetic female presented to the emergency department with complaints of abdominal pain, vomiting and diarrhea. She was on metformin for the last 10 years, but despite compliance to medications, her HbA1c was 14.1. With an aim to improve her glycemic control, linagliptin 5 mg once a day was added 1 month ago. Initial investigations in ED including arterial blood gas analysis revealed metabolic acidosis, ketosis, hyperlactemia, and acute kidney injury. In view of metabolic acidosis and ketosis with elevated blood glucose level, she was diagnosed to have DKA. Compared to isolated DKA, patients with combined MALA and DKA have severe metabolic acidosis, a greater degree of hyperlactatemia but less extensive ketoacidosis. Hence, she was diagnosed to have combined MALA and DKA. She was admitted to intensive care unit and treated with intravenous fluids, insulin infusion, and continuous renal replacement therapy. Her metabolic acidosis, hyperlactemia, and kidney injury resolved and she was discharged well.

Conclusion

This report has shown the importance of rapid diagnosis and management of the rare and challenging diagnosis of combined MALA and DKA. The main goal of therapy is preventing hyperglycemia and ketosis, resolution of metabolic acidosis, and removal of accumulated metformin using intensive therapies like aggressive fluid resuscitation and early initiation of renal replacement therapy. Adjustment of dose of medications is needed to avoid this complication.

Potential Clinical Applications for Continuous Ketone Monitoring in the Hospitalized Patient with Diabetes

PURPOSE OF REVIEW

In this review, the authors discuss potential clinical applications for continuous ketone monitoring (CKM) in a broad continuum of clinical settings from pre-hospital care and the emergency department to acute inpatient management and post-discharge follow-up.

RECENT FINDINGS

Though in its early stages, the concept of a novel continuous ketone sensing technology exerts great potential for use in the detection and hospital management of DKA, namely to overcome diagnostic barriers associated with ketoacidosis in patients with diabetes and obtain real-time BOHB levels, which may be useful in understanding both patients' response to treatment and DKA trajectory. Peri- and intra-operative use of CKM technology can potentially be applied in a number of urgent and elective surgical procedures frequently underwent by patients with diabetes and in the observation of patients during peri-operative fasting. In transitional care management, CKM technology could potentially facilitate patients' safe transition through levels of care, following hospital discharge from a DKA episode. This evaluation of the literature presents the potential advantages of adopting CKM and integrating this technology into the care algorithm of patients at risk for ketoacidosis.

Systemic Beta-Hydroxybutyrate Affects BDNF and Autophagy into the Retina of Diabetic Mice

Background: Diabetic retinopathy (DR) is a neurovascular disease, characterized by a deficiency of brain-derived neurotrophic factor (BDNF), a regulator of autophagy. Beta-hydroxybutyrate (BHB), previously reported as a protective agent in DR, has been associated with BDNF promotion. Here, we investigated whether systemic BHB affects the retinal levels of BDNF and local autophagy in diabetic mice with retinopathy; Methods: C57BL/6J mice were administered with intraperitoneal (i.p.) streptozotocin (STZ) (75 mg/kg) injection to develop diabetes. After 2 weeks, they received i.p. injections of BHB (25−50−100 mg/kg) twice a week for 10 weeks. Retinal samples were collected in order to perform immunofluorescence, Western blotting, and ELISA analysis; Results: BHB 50 mg/kg and 100 mg/kg significantly improved retinal BDNF levels (p < 0.01) in diabetic mice. This improvement was negatively associated with autophagosome−lysosome formations (marked by LC3B and ATG14) and to higher levels of connexin 43 (p < 0.01), a marker of cell integrity. Moreover, BHB administration significantly reduced M1 microglial activation and autophagy (p < 0.01); Conclusions: The systemic administration of BHB in mice with DR improves the retinal levels of BDNF, with the consequent reduction of the abnormal microglial autophagy. This leads to retinal cell safety through connexin 43 restoration.

Correlation between blood ketones and exhaled acetone measured with a semiconducting gas sensor

Breath acetone (BrAce) has been reported to be useful for monitoring the pathophysiology of patients with diabetes. However, devices that measure BrAce are expensive, complex and uncommon. The FM-001, originally designed to monitor a marker of weight loss in healthy people, is a device for measuring BrAce. The FM-001 is a loading semiconducting gas sensor that is a simple and reusable device. The aim of this study was to evaluate the correlation between blood total ketone bodies (TKB) and BrAce measured with the FM-001 in patients with diabetes. Furthermore, through evaluation of that correlation, we sought to detect patients at high risk of developing diabetic ketoacidosis (DKA). Thirty-five participants (Age 52 [40-57], T2DM 32, T1DM 3) were enrolled. Scatter plots and linear regression lines relating BrAce to TKB and the correlation coefficients were calculated. Receiver-operating characteristic (ROC) analysis was performed to determine the cut-off for predicting patients prone to DKA. The results showed that BrAce strongly correlates with TKB (R=0.828), and the correlation was stronger in patients whose serum C-peptide was not low. The optimal BrAce cut-off for predicting risk of developing DKA was 3,400 ppb (AUC 0.924, sensitivity 73.3%, specificity 100%), which corresponds to a TKB ≥ 1,000 µmol/L. BrAce also weakly correlated with free fatty acid. Thus, BrAce levels measured with the FM-001 strongly correlate with TKB, even in patients with diabetes. This suggests the FM-001 is a simple and potentially useful method for detecting diabetic ketosis. (UMIN-ID: UMIN000038086).

Serum ketone body measurement in patients with diabetic ketoacidosis

Background

Diabetic ketoacidosis (DKA) is a critical manifestation in patients with diabetes mellitus. DKA has been conventionally diagnosed by the presence of hyperglycemia (blood glucose levels > 250 mg/dl) and metabolic acidosis (blood gas bicarbonate [HCO₃ ^-] < 18 mmol/l and pH in blood gas < 7.30). However, quantitative evaluation of serum ketone bodies has not been established. The current study investigates serum ketone body levels in patients suspected for DKA.

Methods

We have retrospectively evaluated patients with hyperglycemia whose serum ketone body levels at the outpatient clinic and emergency department were measured simultaneously with blood gas analysis during 2011-2019. Clinical backgrounds, severity of diabetes, serum ketone bodies, and blood gas factors were analyzed.

Results

Seventy-two patients were enrolled in the study, after the exclusion of patients who had ketosis due to factors other than diabetes. Serum ketone body levels were negatively correlated with the levels of blood HCO₃ ^- and pH. By receiver-operating-characteristic curve analyses, optimal cut-off values for diagnosis of DKA were determined at 6.3 mmol/l of beta-hydroxybutyrate, 1.4 mmol/l of acetoacetate, and 8.0 mmol/l of total ketone body, respectively. Moreover, serum ketone bodies appeared to effectively differentiate between type 1 and type 2 diabetes mellitus. The cut-off values were higher than those in previous reports.

Conclusions

Serum ketone body levels were thought to be useful in the diagnosis of DKA. Further investigations with increased numbers of patients are required to establish the appropriate application of serum ketone bodies in patients with DKA.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13340-022-00581-2.

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.

Heterologous expression, characterization and evolution prediction of a diaphorase from Geobacillus sp. Y4.1MC1

β-hydroxybutyric acid is the most sensitive indicator in ketoacidosis detection, and accounts for nearly 78% of the ketone bodies. Diaphorase is commonly used to detect the β-hydroxybutyric acid in clinical diagnosis. However, the extraction of diaphorase from animal myocardium is complex and low-yield, which is not convenient for large-scale production. In this study, a diaphorase from Geobacillus sp. Y4.1MC1 was efficiently heterologous expressed and purified in E. coli with a yield of 110 mg/L culture. The optimal temperature and pH of this recombinant diaphorase (rDIA) were 55 °C and 6.5, respectively. It was proved that rDIA was a dual acid- and thermo-stable enzyme, and which showed much more accurate detection of β-hydroxybutyric acid than the commercial enzyme. Additionally, we also investigated the molecular interaction of rDIA with the substrate, and the conformation transition in different pH values by using homology modeling and molecular dynamics simulation. The results showed that 141-161 domain of rDIA played important role in the structure changes and conformations transmission at different pH values. Moreover, it was predicted that F105W, F105R, and M186R mutants were able to improve the binding affinity of rDIA, and A2Y, P35F, Q36D, N210L, F211Y mutants were benefit for the stability of rDIA.

Comparisons of biochemical parameters and diabetic ketoacidosis severity in adult patients with type 1 and type 2 diabetes

OBJECTIVE

The aim of this study was to determine the differences in biochemical parameters and diabetic ketoacidosis (DKA) severity in adult patients with type 1 and type 2 diabetes and utilization of serum BHB as a biomarker for DKA resolution was also evaluated.

MATERIALS AND METHODS

This prospective observational study of type 1 or type 2 diabetes mellitus who were diagnosed with DKA between 01 October 2018 and 30 September 2020. The correlations between serum BHB, measured by the Ranbut assay, and pH, bicarbonate, and anion gap were examined.

RESULTS

A total of 99 diabetes patients were diagnosed with DKA (mean age 39.4 years, 63.4% female, 53.6% T2DM). while infection was the most common precipitating factor in T2DM (43.4%), non-compliance with treatment was the most common precipitating factor in T1DM (43.5%). T1DM patients had more severe DKA more hypokalemia during treatment. However, there was no significant difference in mortality between type1 and type2 diabetes. The initial laboratories evaluation of patients did not significant differ between type1 and type2 diabetes. Serum BHB during treatment of DKA was significantly correlated with changes in serum bicarbonate (r = - 0.64), serum anion gap (r = 0.84), and venous pH (r = - 0.6). The serum BHB levels corresponding to HCO₃ levels for DKA severity were 4.5, 5.7, and 5.9 mmol/L in mild, moderate, and severe DKA, respectively. The serum BHB level of < 1 mmol/L had 73.7% sensitivity and 100% specificity to predict DKA resolution. Median time to resolution of DKA was 12 h with an optimized BHB cut-off value of < 1 mmol/L. There were no significant difference in time to resolution of DKA in the patients with type 1 and type 2 diabetes.

CONCLUSIONS

There are no differences in DKA-related biochemical parameters between type 1 and type 2 diabetes patients. The present findings suggest that DKA should be assessed and treated similarly, regardless of its occurrence in type 1 or type 2 diabetes patients.

Activation of G protein-coupled receptors by ketone bodies: Clinical implication of the ketogenic diet in metabolic disorders

Ketogenesis takes place in hepatocyte mitochondria where acetyl-CoA derived from fatty acid catabolism is converted to ketone bodies (KB), namely β-hydroxybutyrate (β-OHB), acetoacetate and acetone. KB represent important alternative energy sources under metabolic stress conditions. Ketogenic diets (KDs) are low-carbohydrate, fat-rich eating strategies which have been widely proposed as valid nutritional interventions in several metabolic disorders due to its substantial efficacy in weight loss achievement. Carbohydrate restriction during KD forces the use of FFA, which are subsequently transformed into KB in hepatocytes to provide energy, leading to a significant increase in ketone levels known as "nutritional ketosis". The recent discovery of KB as ligands of G protein-coupled receptors (GPCR) - cellular transducers implicated in a wide range of body functions - has aroused a great interest in understanding whether some of the clinical effects associated to KD consumption might be mediated by the ketone/GPCR axis. Specifically, anti-inflammatory effects associated to KD regimen are presumably due to GPR109A-mediated inhibition of NLRP3 inflammasome by β-OHB, whilst lipid profile amelioration by KDs could be ascribed to the actions of acetoacetate via GPR43 and of β-OHB via GPR109A on lipolysis. Thus, this review will focus on the effects of KD-induced nutritional ketosis potentially mediated by specific GPCRs in metabolic and endocrinological disorders. To discriminate the effects of ketone bodies per se, independently of weight loss, only studies comparing ketogenic vs isocaloric non-ketogenic diets will be considered as well as short-term tolerability and safety of KDs.

Plasma β-Hydroxybutyrate for the Diagnosis of Diabetic Ketoacidosis in the Emergency Department

OBJECTIVE

Diabetic ketoacidosis (DKA) is a common emergency department presentation of both new-onset and established diabetes mellitus (DM). β-Hydroxybutyrate (BOHB) provides a direct measure of the pathophysiologic derangement in DKA as compared with the nonspecific measurements of blood pH and bicarbonate. Our objective was to characterize the relationship between BOHB and DKA.

METHODS

This is a cross-sectional retrospective study of pediatric patients with DM presenting to an urban pediatric emergency department between January 1, 2016, and September 30, 2018. Analyses were performed on each patient's initial, simultaneous BOHB and pH. Diagnostic test characteristics of BOHB were calculated, and logistic regression was performed to investigate the effects of age and other key clinical factors.

RESULTS

Among 594 patients with DM, with median age of 12.3 years (interquartile range, 8.7-15.9 years), 176 (29.6%) presented with DKA. The inclusion of age, transfer status, and new-onset in the statistical model did not improve the prediction of DKA beyond BOHB alone. β-Hydroxybutyrate demonstrated strong discrimination for DKA, with an area under the curve of 0.95 (95% confidence interval, 0.93-0.97). A BOHB value of 5.3 mmol/L predicted DKA with optimal accuracy (90.6% of patients were correctly classified). The sensitivity, specificity, and positive and negative predictive values of this cut point were 76.7% (95% confidence interval, 69.8%-82.7%), 96.4% (94.2%-98.0%), 90.0% (84.0%-94.3%), and 90.8% (87.7%-93.3%), respectively.

CONCLUSIONS

β-Hydroxybutyrate accurately predicts DKA in children and adolescents. More importantly, because plasma BOHB is the ideal biochemical marker of DKA, BOHB may provide a more optimal definition of DKA for management decisions and treatment targets.

Metabolites involved in purine degradation, insulin resistance, and fatty acid oxidation are associated with prediction of Gestational diabetes in plasma

INTRODUCTION

Gestational diabetes mellitus (GDM) significantly increases maternal and fetal health risks, but factors predictive of GDM are poorly understood.

OBJECTIVES

Plasma metabolomics analyses were conducted in early pregnancy to identify potential metabolites associated with prediction of GDM.

METHODS

Sixty-eight pregnant women with overweight/obesity from a clinical trial of a lifestyle intervention were included. Participants who developed GDM (n = 34; GDM group) were matched on treatment group, age, body mass index, and ethnicity with those who did not develop GDM (n = 34; Non-GDM group). Blood draws were completed early in pregnancy (10-16 weeks). Plasma samples were analyzed by UPLC-MS using three metabolomics assays.

RESULTS

One hundred thirty moieties were identified. Thirteen metabolites including pyrimidine/purine derivatives involved in uric acid metabolism, carboxylic acids, fatty acylcarnitines, and sphingomyelins (SM) were different when comparing the GDM vs. the Non-GDM groups (p < 0.05). The most significant differences were elevations in the metabolites' hypoxanthine, xanthine and alpha-hydroxybutyrate (p < 0.002, adjusted p < 0.02) in GDM patients. A panel consisting of four metabolites: SM 14:0, hypoxanthine, alpha-hydroxybutyrate, and xanthine presented the highest diagnostic accuracy with an AUC = 0.833 (95% CI: 0.572686-0.893946), classifying as a "very good panel".

CONCLUSION

Plasma metabolites mainly involved in purine degradation, insulin resistance, and fatty acid oxidation, were altered in early pregnancy in connection with subsequent GDM development.

Salivary Metabolites are Promising Non-Invasive Biomarkers of Hepatocellular Carcinoma and Chronic Liver Disease

Background

Hepatocellular carcinoma (HCC) is a leading causes of cancer mortality worldwide. Improved tools are needed for detecting HCC so that treatment can begin as early as possible. Current diagnostic approaches and existing biomarkers, such as alpha-fetoprotein (AFP) lack sensitivity, resulting in too many false negative diagnoses. Machine-learning may be able to identify combinations of biomarkers that provide more robust predictions and improve sensitivity for detecting HCC. We sought to evaluate whether metabolites in patient saliva could distinguish those with HCC, cirrhosis, and those with no documented liver disease.

Methods and Results

We tested 125 salivary metabolites from 110 individuals (43 healthy, 37 HCC, 30 cirrhosis) and identified 4 metabolites that displayed significantly different abundance between groups (FDR P <.2). We also developed four tree-based, machine-learning models, optimized to include different numbers of metabolites, that were trained using cross-validation on 99 patients and validated on a withheld test set of 11 patients. A model using 12 metabolites -octadecanol, acetophenone, lauric acid, 1-monopalmitin, dodecanol, salicylaldehyde, glycyl-proline, 1-monostearin, creatinine, glutamine, serine and 4-hydroxybutyric acid- had a cross-validated sensitivity of 84.8%, specificity of 92.4% and correctly classified 90% of the HCC patients in the test cohort. This model outperformed previously reported sensitivities and specificities for AFP (20-100ng/ml) (61%, 86%) and AFP plus ultrasound (62%, 88%).

Conclusions and Impact

Metabolites detectable in saliva may represent products of disease pathology or a breakdown in liver function. Notably, combinations of salivary metabolites derived from machine-learning may serve as promising non-invasive biomarkers for the detection of HCC.

Features and long-term outcomes of patients hospitalized for diabetic ketoacidosis

BACKGROUND

Diabetic ketoacidosis (DKA) is an acute metabolic complication characterized by hyperglycaemia, ketones in blood or urine, and acidosis.

OBJECTIVE

The aim of this study was to characterize features of patients hospitalized for DKA, to identify triggers for DKA and to evaluate the long-term effects of DKA on glycaemic control, complications of diabetes, re-hospitalizations, and mortality.

METHODS

Historical prospectively collected data of patients hospitalized to medical wards for DKA between 2011 and 2017. Data regarding comorbidities, mortality, triggers, and re-hospitalizations for DKA were also collected.

RESULTS

The cohort consisted of 160 patients (mean age 38 ± 18 years, 43% male). One fifth of the patients (34 patients, 21%) were newly diagnosed with diabetes, and DKA was their first presentation of the disease. Among the 126 patients with pre-existing diabetes, the common identified triggers for DKA were poor compliance to treatment (22%) and infectious diseases (18%). During over 7 years of follow-up, mortality rate was 9% (15 patients), and re-hospitalization for DKA rate was 31% (50 patients). Risk factors for re-hospitalization for DKA included young age (OR = 1.02, 95% CI, 1.00-1.04), pre-existing diabetes compared to DKA as the first presentation (OR = 5.4, 95% CI, 1.7-18), and poorer glycaemic control before initial hospitalization (10.5 ± 2.5% vs. 9.4 ± 2.2%; OR = 0.8, 95% CI [0.68-0.96]) and after discharge (10.3 ± 2.4% vs. 9.0 ± 1.9%; OR = 0.73, 95% CI [0.61-0.87]). Laboratory tests during the initial hospitalization, smoking, alcohol, or comorbidities did not increase the risk for re-hospitalization for DKA.

CONCLUSIONS

The risk for readmission for DKA is higher for young patients with long duration of diabetes, poor compliance of insulin treatment and poorly controlled diabetes.

Biochemical Parameters of Diabetes Ketoacidosis in Patients with End-stage Kidney Disease and Preserved Renal Function

INTRODUCTION

Differences in biochemical parameters of diabetic ketoacidosis in patients with end-stage kidney disease (ESKD) has not been established. Accordingly, we assessed the relationship between degree of metabolic acidosis and ß-hydroxybutyrate in patients with ESKD (eGFR < 15 mL/min/1.73 m2), moderate renal failure (eGFR 15-60), or preserved renal function (eGFR > 60).

METHODS

This observational study included adults (18-80 years) with diabetes ketoacidosis (DKA), admitted to Emory University Hospitals between January 1, 2006 to December 31, 2016. DKA and renal stages were confirmed on admission laboratory values.

RESULTS

Admission bicarbonate levels (13.9 ± 5 vs 13.4 ± 5.3 vs 13.8 ± 4.2 mmol/L, P = 0.7), and pH levels (7.2 ± 0.3 vs 7.2 ± 0.2 vs 7.2 ± 0.2, P = 0.8) were similar among groups. Patients with ESKD had lower mean ß-hydroxybutyrate level (4.3 ± 3.3 vs 5.6 ± 2.9 vs 5.9 ± 2.5 mmol/L, P = 0.01), but higher admission glucose (852 ± 340.4 vs 714.6 ± 253.3 mg/dL vs 518 ± 185.7 mg/dL, P < 0.01), anion gap (23.4 ± 7.6 vs 23 ± 6.9 vs 19.5 ± 4.7 mmol/L, P < 0.01), and osmolality (306 ± 20.6 vs 303.5 ± vs 293.1 ± 3.1mOsm/kg, P < 0.01) compared with patients with moderate renal failure and preserved renal function, respectively. The sensitivity of ß-hydroxybutyrate > 3 mmol/L for diagnosing DKA by bicarbonate level < 15 and <18 mmol/L was 86.9% and 72% in ESKD, 89.3% and 83.7% in moderate renal failure, and 96.2% and 88.3% in preserved renal function. In patients with ESKD, the corresponding ß-hydroxybutyrate with bicarbonate levels < 10, 10-15, <18 mmol/L were 5.5, 3.9, 3.0 mmol/L, respectively.

CONCLUSIONS

Significant metabolic differences were found among DKA patients with different levels of renal function. In patients with ESKD, a ß-hydroxybutyrate level > 3 mmol/L may assist with confirmation of DKA diagnosis.

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.

Euglycemic diabetic ketoacidosis: Etiologies, evaluation, and management

INTRODUCTION

Diabetic ketoacidosis is an endocrine emergency. A subset of diabetic patients may present with relative euglycemia with acidosis, known as euglycemic diabetic ketoacidosis (EDKA), which is often misdiagnosed due to a serum glucose <250 mg/dL.

OBJECTIVE

This narrative review evaluates the pathogenesis, diagnosis, and management of EDKA for emergency clinicians.

DISCUSSION

EDKA is comprised of serum glucose <250 mg/dL with an anion gap metabolic acidosis and ketosis. It most commonly occurs in patients with a history of low glucose states such as starvation, chronic liver disease, pregnancy, infection, and alcohol use. Sodium-glucose cotransporter-2 (SGLT2) inhibitors, which result in increased urinary glucose excretion, are also associated with EDKA. The underlying pathophysiology involves insulin deficiency or resistance with glucagon release, poor glucose availability, ketone body production, and urinary glucose excretion. Patients typically present with nausea, vomiting, malaise, or fatigue. The physician must determine and treat the underlying etiology of EDKA. Laboratory assessment includes venous blood gas for serum pH, bicarbonate, and ketones. Management includes resuscitation with intravenous fluids, insulin, and glucose, with treatment of the underlying etiology.

CONCLUSIONS

Clinician knowledge of this condition can improve the evaluation and management of patients with EDKA.

Metabolomic Biomarkers for the Detection of Obesity-Driven Endometrial Cancer

Simple Summary

Endometrial cancer is the commonest cancer of the female genital tract and obesity is its main modifiable risk factor. Over 80% of endometrial cancers develop in the context of obesity-induced metabolic changes. This study focuses on the potential of plasma-based metabolites to enable the early detection of endometrial cancer in a cohort of women with body mass index (BMI) ≥ 30 kg/m². Specific lipid metabolites including phospholipids and sphingolipids (sphingomyelins) demonstrated good accuracy for the detection of endometrial cancer, especially when combined in a diagnostic model. This study advances our knowledge of the role of metabolomics in endometrial cancer and provides a basis for the minimally invasive screening of women with elevated BMI.

Abstract

Endometrial cancer is the most common malignancy of the female genital tract and a major cause of morbidity and mortality in women. Early detection is key to ensuring good outcomes but a lack of minimally invasive screening tools is a significant barrier. Most endometrial cancers are obesity-driven and develop in the context of severe metabolomic dysfunction. Blood-derived metabolites may therefore provide clinically relevant biomarkers for endometrial cancer detection. In this study, we analysed plasma samples of women with body mass index (BMI) ≥ 30 kg/m² and endometrioid endometrial cancer (cases, n = 67) or histologically normal endometrium (controls, n = 69), using a mass spectrometry-based metabolomics approach. Eighty percent of the samples were randomly selected to serve as a training set and the remaining 20% were used to qualify test performance. Robust predictive models (AUC > 0.9) for endometrial cancer detection based on artificial intelligence algorithms were developed and validated. Phospholipids were of significance as biomarkers of endometrial cancer, with sphingolipids (sphingomyelins) discriminatory in post-menopausal women. An algorithm combining the top ten performing metabolites showed 92.6% prediction accuracy (AUC of 0.95) for endometrial cancer detection. These results suggest that a simple blood test could enable the early detection of endometrial cancer and provide the basis for a minimally invasive screening tool for women with a BMI ≥ 30 kg/m².

The regulatory enzymes and protein substrates for the lysine β-hydroxybutyrylation pathway

Metabolism-mediated epigenetic changes represent an adapted mechanism for cellular signaling, in which lysine acetylation and methylation have been the historical focus of interest. We recently discovered a β-hydroxybutyrate-mediated epigenetic pathway that couples metabolism to gene expression. However, its regulatory enzymes and substrate proteins remain unknown, hindering its functional study. Here, we report that the acyltransferase p300 can catalyze the enzymatic addition of β-hydroxybutyrate to lysine (Kbhb), while histone deacetylase 1 (HDAC1) and HDAC2 enzymatically remove Kbhb. We demonstrate that p300-dependent histone Kbhb can directly mediate in vitro transcription. Moreover, a comprehensive analysis of Kbhb substrates in mammalian cells has identified 3248 Kbhb sites on 1397 substrate proteins. The dependence of histone Kbhb on p300 argues that enzyme-catalyzed acylation is the major mechanism for nuclear Kbhb. Our study thus reveals key regulatory elements for the Kbhb pathway, laying a foundation for studying its roles in diverse cellular processes.

Acute Metabolic Emergencies in Diabetes: DKA, HHS and EDKA

Emergency admissions due to acute metabolic crisis in patients with diabetes remain some of the most common and challenging conditions. DKA (Diabetic Ketoacidosis), HHS (Hyperglycaemic Hyperosmolar State) and recently focused EDKA (Euglycaemic Diabetic Ketoacidosis) are life-threatening different entities. DKA and HHS have distinctly different pathophysiology but basic management protocols are the same. EDKA is just like DKA but without hyperglycaemia. T1D, particularly children are vulnerable to DKA and T2D, particularly elderly with comorbidities are vulnerable to HHS. But these are not always the rule, these acute conditions are often occur in different age groups with diabetes. It is essential to have a coordinated care from the multidisciplinary team to ensure the timely delivery of right treatment. DKA and HHS, in many instances can present as a mixed entity as well. Mortality rate is higher for HHS than DKA but incidences of DKA are much higher than HHS. The prevalence of HHS in children and young adults are increasing due to exponential growth of obesity and increasing T2D cases in this age group. Following introduction of SGLT2i (Sodium-GLucose co-Transporter-2 inhibitor) for T2D and off-label use in T1D, some incidences of EDKA has been reported. Healthcare professionals should be more vigilant during acute illness in diabetes patients on SGLT2i without hyperglycaemia to rule out EDKA. Middle aged, mildly obese and antibody negative patients who apparently resemble as T2D without any precipitating causes sometime end up with DKA which is classified as KPD (Ketosis-prone diabetes). Many cases can be prevented by following 'Sick day rules'. Better access to medical care, structured diabetes education to patients and caregivers are key measures to prevent acute metabolic crisis.

Use of capillary ketones monitoring in treatment of mild ketotic crisis in people with ketosis-prone atypical diabetes

This study was carried out to assess the potential reduction in duration of intensive diabetic ketoacidosis treatment in adults with ketosis-prone atypical diabetes (KPD) when using capillary versus urinary ketones. In this cross-sectional study, we included 20 people with KPD presented at the National Obesity Center of the Yaoundé Central Hospital with hyperglycemic decompensation (random capillary glucose ≥13 mmol/L) and significant ketosis (ketonuria≥++) requiring intensive insulin treatment. In all subjects, intensive insulin treatment was initiated at 10 UI per hour with simultaneous measurement of capillary beta-hydroxybutyrate and ketonuria every 2 hours until disappearance of ketonuria. Time-to-disappearance of urine ketones was compared with the time-to-normalization of capillary β-hydroxybutyrate concentrations. Subjects were aged 46±13 years with a median duration of diabetes of 1.5 (IQR: 0-2.5) years. On admission, the mean blood glucose was 22.8±5 mmol/L and capillary ketones level was 2.9±2.7 mmol/L. The median time-to-disappearance of ketonuria was 5 (IQR: 3-8) hours compared with the time-to-normalization of capillary β-hydroxybutyrate of 4 (IQR: 2-6) hours, p=0.0002. The absolute difference in time-to-normalization of ketonuria versus ketonemia was 2 (IQR: 1-3) hours and the relative time reduction of treatment was 32.5%±18.0%. Our results suggested that the use of capillary ketones versus ketonuria would allow a significant reduction in duration of intensive insulin treatment by one third in people with KPD.

Diabetic ketoacidosis

Diabetic ketoacidosis (DKA) is the most common acute hyperglycaemic emergency in people with diabetes mellitus. A diagnosis of DKA is confirmed when all of the three criteria are present - 'D', either elevated blood glucose levels or a family history of diabetes mellitus; 'K', the presence of high urinary or blood ketoacids; and 'A', a high anion gap metabolic acidosis. Early diagnosis and management are paramount to improve patient outcomes. The mainstays of treatment include restoration of circulating volume, insulin therapy, electrolyte replacement and treatment of any underlying precipitating event. Without optimal treatment, DKA remains a condition with appreciable, although largely preventable, morbidity and mortality. In this Primer, we discuss the epidemiology, pathogenesis, risk factors and diagnosis of DKA and provide practical recommendations for the management of DKA in adults and children.

Review article: Ketoacidosis in the emergency department

Diabetic ketoacidosis, a life-threatening complication of type 1 diabetes mellitus, is a common cause of presentation to EDs. Two new drug classes have been found to cause ketoacidosis with distinctive presentations. The sodium-glucose transport protein 2 inhibitors used in the management of type 2 diabetes mellitus may present with ketoacidosis with normal glucose levels. Ketoacidosis with these medications may be prolonged and recur after initial resolution. Checkpoint inhibitors may present with fulminant diabetic ketoacidosis in individuals with previously normal glucose tolerance. Ketoacidosis may also occur as a result of starvation and alcohol excess, as well as a number of rare causes. Other causes of metabolic acidosis with both high and normal anion gap need to be considered in the differential diagnosis of ketoacidosis. Diabetic ketoacidosis may also present with biochemical changes suggestive of myocardial ischaemia and pancreatitis in the absence of these pathologies. The present paper reviews ketone body metabolism, ketone testing and the causes and differential diagnosis of ketoacidosis with particular relevance to emergency medicine.

n-3 Fatty Acid and Its Metabolite 18-HEPE Ameliorate Retinal Neuronal Cell Dysfunction by Enhancing Müller BDNF in Diabetic Retinopathy

Diabetic retinopathy (DR) is a widespread vision-threatening disease, and neuroretinal abnormality should be considered as an important problem. Brain-derived neurotrophic factor (BDNF) has recently been considered as a possible treatment to prevent DR-induced neuroretinal damage, but how BDNF is upregulated in DR remains unclear. We found an increase in hydrogen peroxide (H₂O₂) in the vitreous of patients with DR. We confirmed that human retinal endothelial cells secreted H₂O₂ by high glucose, and H₂O₂ reduced cell viability of MIO-M1, Müller glia cell line, PC12D, and the neuronal cell line and lowered BDNF expression in MIO-M1, whereas BDNF administration recovered PC12D cell viability. Streptozocin-induced diabetic rats showed reduced BDNF, which is mainly expressed in the Müller glia cell. Oral intake of eicosapentaenoic acid ethyl ester (EPA-E) ameliorated BDNF reduction and oscillatory potentials (OPs) in electroretinography (ERG) in DR. Mass spectrometry revealed an increase in several EPA metabolites in the eyes of EPA-E-fed rats. In particular, an EPA metabolite, 18-hydroxyeicosapentaenoic acid (18-HEPE), induced BDNF upregulation in Müller glia cells and recovery of OPs in ERG. Our results indicated diabetes-induced oxidative stress attenuates neuroretinal function, but oral EPA-E intake prevents retinal neurodegeneration via BDNF in Müller glia cells by increasing 18-HEPE in the early stages of DR.

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.

New Test, Old Disease: A Case Series of Diabetic Ketoalkalosis

BACKGROUND

Diabetic ketoalkalosis (DKAlk) was first described in 1967 as a rare complication of diabetic ketoacidosis with normal or elevated pH/bicarbonate and elevated anion gap (AG) from high β-hydroxybutyrate (BHB).

OBJECTIVE

We report a case series of patients with DKAlk to show how venous blood gas (VBG) electrolytes alone may misdiagnose these patients.

METHODS

This was a case series of DKAlk patients with concomitant VBG and basic metabolic panel (BMP) electrolytes who met the following criteria for DKAlk: BMP hyperglycemia (glucose >250 mg/dL), elevated AG (>15 mEq/L), elevated BHB (>1.2 mmol/L), and high Delta (Δ) gap (>6 mEq/L [bicarbonate gap (BG): measured bicarbonate - 24] - [AG - 12]). Data are reported as median with interquartile range (IQR) (25%, 75%) and group comparisons utilized Mann-Whitney U test (two-tailed, α = 0.05).

RESULTS

We found 10 patients with DKAlk in 2 months. Patients ranged in age from 13 to 77 years, 50% were male, and all were African American. Most patients (8 of 10) were vomiting with hyperglycemia (350 to >600 mg/dL). DKAlk BMP AG ranged from 18 to 34 mmol/L and BHB from 1.74 to 9.09 mmol/L. For bicarbonate, we found no significant difference between VBG (24 mmol/L) and BMP (22 mmol/L) (p = 0.796). VBG chloride (98 mmol/L) was significantly higher than BMP chloride (88 mmol/L) (p < 0.005). This falsely elevated VBG chloride resulted in undervaluing of all VBG AGs, missing almost all of the patients with DKAlk.

CONCLUSIONS

We found that DKAlk is more common than previously reported. We recommend screening with BMP electrolytes and BHB levels for hyperglycemic ED patients who are vomiting or suspected of hypovolemia.

The Clinical Case for the Integration of a Ketone Sensor as Part of a Closed Loop Insulin Pump System

Closed loop (CL) systems deliver insulin with a rapid onset and offset in action. Although favorable overall, the absence of a long-acting insulin increases the risk of diabetic ketoacidosis (DKA) which can occur with insulin delivery failure, acute illness, low carbohydrate diets, sodium glucose-linked transporter inhibitors, and high intensity exercise. A CL system relying entirely on interstitial glucose measurements may not provide an alert for DKA and many people with type 1 diabetes (T1D) do not carry a blood ketone meter and test-strips. Ketone sensing is theoretically feasible. A multianalyte platform incorporating a ketone sensor could provide an additional CL input without an increase in burden for the person with T1D, warning of impending DKA to allow remedial action to be taken. We outline the clinical case for inclusion of continuous ketone sensing as part of future CL systems.

Challenges in management of diabetic ketoacidosis in hemodialysis patients, case presentation and review of literature

Chronic kidney disease is associated with accumulation of uremic toxins that increases insulin resistance which will lead to blunted ability to suppress hepatic gluconeogenesis and reduce peripheral utilization of insulin. CKD patients fail to increase insulin secretion in response to insulin resistance because of acidosis, 1,25 vitamin D deficiency, and secondary hyperparathyroidism. Hemodialysis causes further fluctuations in glycemic control due to alterations in insulin secretion, clearance and resistance. DKA is uncommon in hemodialysis patients because of the absence of glycosuria and osmotic diuresis which accounts for most of the fluid and electrolyte losses seen in DKA, anuric patients may be somewhat protected from dehydration and shock, although still subject to hyperkalemia and metabolic acidosis. However, substantial volume loss can still occur due to a prolonged decrease in oral intake or increased insensible water losses related to tachypnoea and fever. There is no current guidelines for the management of diabetic ketoacidosis in anuric hemodialysis patients considering their differences than general population. In this review article we reviewed the literature and came with specific recommendations for management of Ketoacidosis in patients with CKD treated by hemodialysis.

International Consensus on Risk Management of Diabetic Ketoacidosis in Patients With Type 1 Diabetes Treated With Sodium-Glucose Cotransporter (SGLT) Inhibitors

Sodium-glucose cotransporter (SGLT) inhibitors are new oral antidiabetes medications shown to effectively reduce glycated hemoglobin (A1C) and glycemic variability, blood pressure, and body weight without intrinsic properties to cause hypoglycemia in people with type 1 diabetes. However, recent studies, particularly in individuals with type 1 diabetes, have demonstrated increases in the absolute risk of diabetic ketoacidosis (DKA). Some cases presented with near-normal blood glucose levels or mild hyperglycemia, complicating the recognition/diagnosis of DKA and potentially delaying treatment. Several SGLT inhibitors are currently under review by the U.S. Food and Drug Administration and European regulatory agencies as adjuncts to insulin therapy in people with type 1 diabetes. Strategies must be developed and disseminated to the medical community to mitigate the associated DKA risk. This Consensus Report reviews current data regarding SGLT inhibitor use and provides recommendations to enhance the safety of SGLT inhibitors in people with type 1 diabetes.

Raman spectral signatures of urinary extracellular vesicles from diabetic patients and hyperglycemic endothelial cells as potential biomarkers in diabetes

Raman spectroscopy was applied to the measurement of urinary and in vitro endothelium-derived extracellular vesicles (EVs) isolated by hydrostatic filtration dialysis (HFD) method. Raman spectra obtained for urinary EVs (UEVs) showed distinct differences in the fingerprint region. In contrast, average Raman spectra of endothelium-derived EVs samples were almost identical. Cluster Analysis of UEVs significantly discriminated diabetic samples from control, moreover endothelium-derived EVs revealed stronger similarity between long hyperglycemia and normoglycemia samples compared to short hyperglycemia. Results obtained from Partial Least Squares analysis corresponded well with integral intensities of selected bands. Our proof-of-concept approach demonstrates the potential for Raman spectroscopy to be used both for identification of EVs molecular signatures in urine samples from patients with type 2 diabetes mellitus and good glycemic control and unsatisfactory glycemic control as well as for in vitro hyperglycemic model. This noninvasive technique may be useful in identifying new biomarkers of diabetes and renal complications.

Utilizing serum bicarbonate instead of venous pH to transition from intravenous to subcutaneous insulin shortens the duration of insulin infusion in pediatric diabetic ketoacidosis

Background Standard therapy of diabetic ketoacidosis (DKA) in pediatrics involves intravenous (IV) infusion of regular insulin until correction of acidosis, followed by transition to subcutaneous (SC) insulin. It is unclear what laboratory marker best indicates correction of acidosis. We hypothesized that an institutional protocol change to determine correction of acidosis based on serum bicarbonate level instead of venous pH would shorten the duration of insulin infusion and decrease the number of pediatric intensive care unit (PICU) therapies without an increase in adverse events. Methods We conducted a retrospective (pre/post) analysis of records for patients admitted with DKA to the PICU of a large tertiary care children's hospital before and after a transition-criteria protocol change. Outcomes were compared between patients in the pH transition group (transition when venous pH≥7.3) and the bicarbonate transition group (transition when serum bicarbonate ≥15 mmol/L). Results We evaluated 274 patient records (n=142 pH transition group, n=132 bicarbonate transition group). Duration of insulin infusion was shorter in the bicarbonate transition group (18.5 vs. 15.4 h, p=0.008). PICU length of stay was 3.2 h shorter in the bicarbonate transition group (26.0 vs. 22.8 h, p=0.04). There was no difference in the number of adverse events between the groups. Conclusions Transitioning patients from IV to SC insulin based on serum bicarbonate instead of venous pH led to a shorter duration of insulin infusion with a reduction in the number of PICU therapies without an increase in the number of adverse events.

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.

Characterization of variable presentations of diabetic ketoacidosis based on blood ketone levels and major society diagnostic criteria: a new view point on the assessment of diabetic ketoacidosis

AIM

We aimed to evaluate the clinical utility of blood ketone measurement and to test the performance of the diagnostic criteria for diabetic ketoacidosis (DKA) issued by the American Diabetes Association, the Joint British Diabetes Societies, and the American Association of Clinical Endocrinologists and the American College of Endocrinology.

METHODS

This retrospective analysis included 278 patients with suspected DKA who were hospitalized at 4 university hospitals and aged ≥16 years with a blood glucose level of >200 mg/dL and a blood ketone level of ≥1.0 mmol/L as well as other biochemical data. The patients were categorized into four subgroups (ketosis, typical DKA, atypical DKA, and DKA + lactic acidosis). Atypical DKA in each analysis was defined by our supplementary criteria if the biochemical data did not meet each set of diagnostic criteria from the aforementioned societies.

RESULTS

Blood ketone levels in patients with diabetic ketosis and those with DKA varied widely, 1.05-5.13 mmol/L and 1.02-15.9 mmol/L, respectively. Additionally, there were significant discrepancies between the guidelines in the diagnosis of DKA. Thus, the proportion of patients with atypical DKA ranged from 16.5% to 42.4%. Notably, the in-hospital mortality was comparable between patients with typical and atypical DKA, with a very high mortality in patients with DKA + lactic acidosis (blood lactate >5 mmol/L).

CONCLUSIONS

Our results showed that considering variable presentations of DKA, blood ketone data need to be interpreted cautiously along with other biochemical data and suggested that a new system is required to better characterize DKA.

Hormonal, Metabolic and Hemodynamic Adaptations to Glycosuria in Type 2 Diabetes Patients Treated with Sodium-Glucose Co-Transporter Inhibitors

BACKGROUND & INTRODUCTION

The advent of the sodium-glucose cotransporter-2 inhibitors [SGLT-2i] provides an additional tool to combat diabetes and complications. The use of SGLT-2i leads to effective and durable glycemic control with important reductions in body weight/fat and blood pressure. These agents may delay beta-cell deterioration and improve tissue insulin sensitivity, which might slow the progression of the disease.

METHODS & RESULTS

In response to glycosuria, a compensatory rise in endogenous glucose production, sustained by a decrease in plasma insulin with an increase in glucagon has been described. Other possible mediators have been implicated and preliminary findings suggest that a sympathoadrenal discharge and/or rapid elevation in circulating substrates (i.e., fatty acids) or some yet unidentified humoral factors may have a role in a renal-hepatic inter-organ relationship. A possible contribution of enhanced renal gluconeogenesis to glucose entry into the systemic circulation has not yet been ruled out. Additionally, tissue glucose utilization decreases, whereas adipose tissue lipolysis is stimulated and, there is a switch to lipid oxidation with the formation of ketone bodies; the risk for keto-acidosis may limit the use of SGLT-2i. These metabolic adaptations are part of a counter-regulatory response to avoid hypoglycemia and, as a result, limit the SGLT-2i therapeutic efficacy. Recent trials revealed important cardiovascular [CV] beneficial effects of SGLT-2i drugs when used in T2DM patients with CV disease. Although the underlying mechanisms are not fully understood, there appears to be "class effect". Changes in hemodynamics and electrolyte/body fluid distribution are likely involved, but there is no evidence for anti-atherosclerotic effects.

CONCLUSION

It is anticipated that, by providing durable diabetes control and reducing CV morbidity and mortality, the SGLT-2i class of drugs is destined to become a priority choice in diabetes management.