Is capillary ketone determination useful in clinical practice? In which circumstances?

Risk for ketonaemia in type 1 diabetes pregnancies with sensor-augmented pump therapy with predictive low glucose suspend compared with low glucose suspend: a crossover RCT

AIMS

To determine the frequency of ketonaemia in pregnant women with type 1 diabetes treated with a sensor-augmented pump (SAP) in predictive low glucose suspend (PLGS) mode compared with low glucose suspend (LGS) mode.

METHODS

An open-label crossover pilot RCT in ten women with type 1 diabetes treated with a 640 Medtronic insulin pump, with inclusion between 12-30 weeks of pregnancy. Participants were 1/1 randomly assigned (allocation by statistician using a permuted block size of 2) to either 2 weeks with an SAP in PLGS mode or 2 weeks in LGS mode. After the first 2 weeks, participants were switched to the other mode. Ketones in the participants' serum were measured three times daily (fasting, midday and evening) during the 4 weeks. The primary endpoint was the frequency of blood ketones > 0.6 mmol/l. Participants and healthcare providers were not blinded to group assignment for assessment of outcomes.

RESULTS

The median gestational week at inclusion was 12.5 weeks (12.0-15.0), participants had a median age of 31.5 years (24.0-33.0), BMI of 26.6 kg/m² (24.5-31.8), baseline HbA_1c of 41 mmol/mol (40-43; 5.9% [5.8-6.1]) and baseline time in range (TIR, 3.5-7.8 mmol/l) of 64.6% (55.6-68.7). Comparing the LGS mode with the PLGS mode, insulin suspension time per day was 2.0 h (1.3-2.3) vs 3.5 h (3.3-5.0; p = 0.002), ketonaemia > 0.6 mmol/l was 0% vs 0.5% (p = 1.000) and no participants had ketonaemia > 1 mmol/l. TIR on LGS was 64.7% (58.0-68.7) vs 61.1% (56.5-67.5) on PLGS (p = 0.492), time < 3.5 mmol/l was higher on LGS at 7.5% (4.6-8.3) vs 4.2% (2.4-6.9) on PLGS (p = 0.014). Treatment satisfaction and fear for hypoglycaemia were similar whether using LGS or PLGS mode.

CONCLUSIONS/INTERPRETATION

Despite longer time periods with suspended insulin delivery, pregnant women using an SAP in PLGS mode were not at higher risk of developing ketonaemia compared with those in LGS mode. Women with an SAP in PLGS mode had similar TIR with less time in hypoglycaemia.

TRIAL REGISTRATION

Clinical Trials NCT04292509 FUNDING: This research received no specific grant from any funding agency in the public, commercial or not-for-profit sectors.

Measuring ketone bodies for the monitoring of pathologic and therapeutic ketosis

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Ketones in Pregnancy: Why Is It Considered Necessary to Avoid Them and What Is the Evidence Behind Their Perceived Risk?

Current dietary advice for women with gestational diabetes mellitus is to avoid diets that result in elevated ketone levels. This guidance stems from a concern that maternal ketones are associated with poor fetal and childhood outcomes, including reduced childhood intelligence quota. The evidence behind these guidelines is conflicting and inconsistent. Given that dietary counseling is the initial treatment strategy for women with diabetes in pregnancy, it is important that clinicians understand the concern regarding maternal ketones. This review examines the physiology of ketogenesis in pregnancy, the prevalence of elevated maternal ketone levels, and the relationship between maternal ketones and fetal and childhood outcomes.

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.

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.

Diabetic ketoacidosis and hyperglycemic hyperosmolar state

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

Blood β-hydroxybutyrate vs. urine acetoacetate testing for the prevention and management of ketoacidosis in Type 1 diabetes: a systematic review

AIM

Diabetic ketoacidosis is a life-threatening complication of Type 1 diabetes. Blood β-hydroxybutyrate testing is now widely available as an alternative to urine acetoacetate testing for detecting ketosis. The aim of this study was to review the effectiveness of capillary or serum β-hydroxybutyrate compared with urine acetoacetate testing in prevention and management of diabetic ketoacidosis.

METHODS

MEDLINE, EMBASE, EBM Reviews, The Cochrane Library and CINAHL (until April 2012, no language restrictions, studies in humans) were searched for experimental and observational studies comparing the effectiveness of blood β-hydroxybutyrate and urine acetoacetate testing. Outcomes examined were prevention of diabetic ketoacidosis, time to recovery from diabetic ketoacidosis, healthcare costs and patient or caregiver satisfaction. Additional sources included reference lists, conference proceedings and contact with experts in the field.

RESULTS

Four studies (two randomized controlled trials and two cohort studies) met eligibility criteria, including 299 participants across 11 centres. Risk of bias was low to moderate. Blood ketone testing compared with urine testing was associated with reduced frequency of hospitalization (one study), reduced time to recovery from diabetic ketoacidosis (three studies), cost benefits (one study) and greater satisfaction (one study, intervention group only). No study assessed prevention of diabetic ketoacidosis. Meta-analysis could not be performed because of heterogeneity in study design and published data.

CONCLUSIONS

There is evidence suggesting that blood β-hydroxybutyrate testing is more effective than urine acetoacetate testing in reducing emergency department assessment, hospitalization and time to recovery from diabetic ketoacidosis, as well as potentially lowering healthcare expenditure. Further research in both young people and adults is needed.

Pediatric diabetic ketoacidosis management in the era of standardization

Up to 70% of children with new-onset Type 1 diabetes mellitus (T1DM) present with diabetic ketoacidosis (DKA), with most cases initially assessed by their primary care provider. DKA is the most common cause of death in children with T1DM, mainly related to cerebral edema that occurs at a frequency of 0.15-4.6%. Early recognition of DKA can be improved by increasing the awareness of early clinical symptoms such as enuresis, polyuria and polydipsia. Clinical acumen paired with early assessment of patients with suspected T1DM and known T1DM, particularly if risk factors for DKA are present, can prevent serious complications and fatal outcomes. Urgent referral to specialist centers for suspected new-onset T1DM/DKA is required. A standardized approach is recommended to be followed to ensure successful initial management of DKA, both in the nonspecialist setting before transfer and in the more specialized hospital setting. This article outlines such a management approach.

Measurement of fasting ketonuria and capillary blood glucose after main meals in women with gestational diabetes mellitus: How well is the metabolic picture captured?

AIM

Metabolic monitoring of women with gestational diabetes mellitus (GDM) usually consists of measuring fasting ketonuria and postprandial capillary blood glucose (CBG) after main meals. We aimed to evaluate how this monitoring system captures the metabolic picture as compared to a scheme with a greater number of time points.

METHODS

Thirty-five women with GDM were recommended to follow a fractionated diet and trained in CBG and ketonuria monitoring. They were asked to monitor ketonuria before a main meal, and to monitor CBG at fasting and 1 h postprandial after any two of the six daily meals. Participants were requested to monitor different meals each day. The goal for 1 h postprandial CBG was <135 mg/dL (7.5 mmol/L). Ketonuria was defined as significant before a certain meal when ≥30% of measurements at that point were positive. Similarly, postprandial CBG was defined as abnormal after a meal when ≥30% measurements exceeded the goal.

RESULTS

Ketonuria was significant in 22.5% of the time points and 41.2% of women had significant ketonuria at one or more time points; 61% of the time points and 35.7% of the women with significant ketonuria would have been undetected with monitoring restricted to breakfast. Postprandial CBG was abnormal in 17.6% of meals and 57% of women had abnormal postprandial CBG at one or more meals; 37.8% of points and 15% of women with abnormal postprandial CBG would have been undetected with monitoring restricted to main meals.

CONCLUSION

A substantial proportion of metabolic abnormalities in GDM women are not detected with a monitoring program that measures only fasting ketonuria and postprandial CBG after main meals.

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.

[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.

Chemo/bio-sensor networks

The concept of wireless sensor networks conjures up images of a world of ubiquitous sensing, but it requires a massive increase in the number of sensors available. Although there has been considerable activity in transducer-based 'sensor nets', there have been virtually no corresponding deployments of chemical- or biological-sensing networks - considerable advances in materials science are needed before these can be used on a large scale.