Explainable Machine Learning for Real-Time Hypoglycemia and Hyperglycemia Prediction and Personalized Control Recommendations

BACKGROUND

The occurrences of acute complications arising from hypoglycemia and hyperglycemia peak as young adults with type 1 diabetes (T1D) take control of their own care. Continuous glucose monitoring (CGM) devices provide real-time glucose readings enabling users to manage their control proactively. Machine learning algorithms can use CGM data to make ahead-of-time risk predictions and provide insight into an individual's longer term control.

METHODS

We introduce explainable machine learning to make predictions of hypoglycemia (<70 mg/dL) and hyperglycemia (>270 mg/dL) up to 60 minutes ahead of time. We train our models using CGM data from 153 people living with T1D in the CITY (CGM Intervention in Teens and Young Adults With Type 1 Diabetes)survey totaling more than 28 000 days of usage, which we summarize into (short-term, medium-term, and long-term) glucose control features along with demographic information. We use machine learning explanations (SHAP [SHapley Additive exPlanations]) to identify which features have been most important in predicting risk per user.

RESULTS

Machine learning models (XGBoost) show excellent performance at predicting hypoglycemia (area under the receiver operating curve [AUROC]: 0.998, average precision: 0.953) and hyperglycemia (AUROC: 0.989, average precision: 0.931) in comparison with a baseline heuristic and logistic regression model.

CONCLUSIONS

Maximizing model performance for glucose risk prediction and management is crucial to reduce the burden of alarm fatigue on CGM users. Machine learning enables more precise and timely predictions in comparison with baseline models. SHAP helps identify what about a CGM user's glucose control has led to predictions of risk which can be used to reduce their long-term risk of complications.

Syndrome of inappropriate secretion of anti-diuretic hormone due to hypothalamic hamartoma: use of tolvaptan

OBJECTIVES

Hypothalamic hamartoma (HH) typically presents with gonadotrophin-dependent precocious puberty and/or seizures. Other endocrine disturbances are rare. We describe an infant with syndrome of inappropriate secretion of anti-diuretic hormone (SIADH) and a HH.

CASE PRESENTATION

A 6-week-old infant presented with seizures and life-threatening hyponatremia. A HH was identified on magnetic resonance imaging. Clinical examination and biochemistry were consistent with SIADH, and serum copeptin was high during hyponatremia, further supporting this diagnosis. Tolvaptan was effective in normalizing plasma sodium and enabling liberalization of fluids to ensure sufficient nutritional intake and weight gain and manage hunger.

CONCLUSIONS

Hyponatremia due to SIADH is novel at presentation of a HH, and can be challenging to diagnose and manage. Successful management of hyponatremia in this case was achieved using tolvaptan.

Cambridge hybrid closed-loop algorithm in children and adolescents with type 1 diabetes: a multicentre 6-month randomised controlled trial

BACKGROUND

Closed-loop insulin delivery systems have the potential to address suboptimal glucose control in children and adolescents with type 1 diabetes. We compared safety and efficacy of the Cambridge hybrid closed-loop algorithm with usual care over 6 months in this population.

METHODS

In a multicentre, multinational, parallel randomised controlled trial, participants aged 6-18 years using insulin pump therapy were recruited at seven UK and five US paediatric diabetes centres. Key inclusion criteria were diagnosis of type 1 diabetes for at least 12 months, insulin pump therapy for at least 3 months, and screening HbA1c levels between 53 and 86 mmol/mol (7·0-10·0%). Using block randomisation and central randomisation software, we randomly assigned participants to either closed-loop insulin delivery (closed-loop group) or to usual care with insulin pump therapy (control group) for 6 months. Randomisation was stratified at each centre by local baseline HbA1c. The Cambridge closed-loop algorithm running on a smartphone was used with either (1) a modified Medtronic 640G pump, Medtronic Guardian 3 sensor, and Medtronic prototype phone enclosure (FlorenceM configuration), or (2) a Sooil Dana RS pump and Dexcom G6 sensor (CamAPS FX configuration). The primary endpoint was change in HbA1c at 6 months combining data from both configurations. The primary analysis was done in all randomised patients (intention to treat). Trial registration ClinicalTrials.gov, NCT02925299.

FINDINGS

Of 147 people initially screened, 133 participants (mean age 13·0 years [SD 2·8]; 57% female, 43% male) were randomly assigned to either the closed-loop group (n=65) or the control group (n=68). Mean baseline HbA1c was 8·2% (SD 0·7) in the closed-loop group and 8·3% (0·7) in the control group. At 6 months, HbA1c was lower in the closed-loop group than in the control group (between-group difference -3·5 mmol/mol (95% CI -6·5 to -0·5 [-0·32 percentage points, -0·59 to -0·04]; p=0·023). Closed-loop usage was low with FlorenceM due to failing phone enclosures (median 40% [IQR 26-53]), but consistently high with CamAPS FX (93% [88-96]), impacting efficacy. A total of 155 adverse events occurred after randomisation (67 in the closed-loop group, 88 in the control group), including seven severe hypoglycaemia events (four in the closed-loop group, three in the control group), two diabetic ketoacidosis events (both in the closed-loop group), and two non-treatment-related serious adverse events. There were 23 reportable hyperglycaemia events (11 in the closed-loop group, 12 in the control group), which did not meet criteria for diabetic ketoacidosis.

INTERPRETATION

The Cambridge hybrid closed-loop algorithm had an acceptable safety profile, and improved glycaemic control in children and adolescents with type 1 diabetes. To ensure optimal efficacy of the closed-loop system, usage needs to be consistently high, as demonstrated with CamAPS FX.

FUNDING

National Institute of Diabetes and Digestive and Kidney Diseases.

Ethnic variation in deep lateral orbital anatomy and its implications on decompression surgery

AIM

To describe differences in the deep lateral orbital wall (specifically, trigone) between Chinese, Malay, Indian and Caucasian subjects Methods: Single-centre retrospective Computed Tomogram (CT)-based study; 20 subjects of each ethnicity were used from existing databases, matched for gender, average age and laterality. Subjects below 16 years of age were excluded. DICOM image viewing software CARESTREAM Vue PACS (Carestream Health Inc., USA) and OsiriX version 7.5 (Pixmeo., Switzerland) were used to measure deep lateral wall length, thickness and volume, as well as orbital depth and statistical analyses performed using Statistical Package for Social Sciences version 21 (IBM, USA).

RESULTS

In each group, there were 12 males (60%) and average age was not significantly different (p = 0.682-0.987). Using Chinese subjects as a reference, in Chinese, Malay, Indian and Caucasian subjects, mean trigone thickness was 13.68, 14.02, 11.60 (p < 0.001) and 13.80 mm, curved total wall length 45.23, 42.29 (p = 0.048), 41.91 (p = 0.020) and 45.00 mm, curved trigone length 23.03, 22.61, 17.19 (p = 0.011) and 18.76 mm (p = 0.030) and trigone volume 3120.97, 3221.01, 1613.66 (p < 0.001), 2498.46 mm³ (p = 0.059) respectively. Similarly, perpendicular orbital depth was 27.54, 24.97, 22.12 (p = 0.001) and 25.93 mm and diagonal orbital depth was 34.19, 33.27, 29.48 (p = 0.01) and 34.63 mm respectively.

CONCLUSIONS

Indian and, to a lesser extent, Caucasian subjects have smaller trigones compared to their Chinese and Malay counterparts. Indian subjects also have shallower orbits and due care should be taken during decompression surgery.

Case Histories

Conditions related to abnormalities of calcium and bone metabolism are large in number and are characterised by hypocalcaemia, hypercalcaemia, primary and secondary osteoporosis, rickets resulting from both vitamin D and phosphate metabolism disorders, and a series of miscellaneous conditions. Included in this chapter is a series of cases drawn from our clinics and from colleagues who have presented these clinical problems at the recent Advanced Courses in Paediatric Bone and Calcium Metabolism run by the British Paediatric and Adolescent Bone group. This series of cases is not fully comprehensive but is designed to cover the major aspects of bone- and calcium-related disorders.

Clinical and molecular characterisation of hyperinsulinaemic hypoglycaemia in infants born small-for-gestational age

OBJECTIVE

To characterise the phenotype and genotype of neonates born small-for-gestational age (SGA; birth weight <10th centile) who developed hyperinsulinaemic hypoglycaemia (HH).

METHODS

Clinical information was prospectively collected on 27 SGA neonates with HH, followed by sequencing of KCNJ11 and ABCC8.

RESULTS

There was no correlation between the maximum glucose requirement and serum insulin levels. Serum insulin level was undetectable in five infants (19%) during hypoglycaemia. Six infants (22%) required diazoxide treatment >6 months. Normoglycaemia on diazoxide <5 mg/kg/day was a safe predictor of resolved HH. Sequencing of KCNJ11/ABCC8 did not identify any mutations.

CONCLUSIONS

Serum insulin levels during hypoglycaemia taken in isolation can miss the diagnosis of HH. SGA infants may continue to have hypofattyacidaemic hypoketotic HH beyond the first few weeks of life. Recognition and treatment of this group of patients are important and may have important implications for neurodevelopmental outcome of these patients.

Mutational analysis of the GYS2 gene in patients diagnosed with ketotic hypoglycaemia

BACKGROUND

Ketotic hypoglycaemia is a common form of hypoglycaemia in childhood. Biochemically, patients present with fasting hypoglycaemia but with normal hormonal and metabolite profiles (low serum alanine levels in some patients). Glycogen Storage Disease Type 0 (GSD0) is an autosomal recessive disease due to mutations in the GYS2 gene. Patients with GSD0 also present with fasting ketotic hypoglycaemia. The frequency of GSD0 in patients presenting with ketotic hypoglycaemia is not known.

OBJECTIVE

To understand the frequency of GSD0 in patients presenting with ketotic hypoglycaemia and to report a novel mutation in the GYS2 gene.

SUBJECTS

The GYS2 gene was sequenced in 50 patients diagnosed with ketotic hypoglycaemia.

METHODS

All exons (including exon and intron boundaries) of the GYS2 gene were sequenced following amplification of the coding region by polymerase chain reaction (PCR).

RESULTS

No mutations in GYS2 were found in 49 patients. One patient had a novel homozygous mutation (c.1802T>G; p. Leu601X) in exon 14 of the GYS2 gene. We believe this is the 18th mutation reported so far. This mutation is predicted to lead to premature truncation of the glycogen synthase protein with no function. This patient presented with fasting ketotic hypoglycaemia associated with postprandial hyperglycaemia and elevated lactate level.

CONCLUSIONS

GSD0 is relatively rare in patients presenting with ketotic hypoglycaemia and a normal biochemical profile. Sequencing of the GYS2 gene is more likely to be positive in patients with fasting ketotic hypoglycaemia and concomitant postprandial hyperglycaemia with hyperlactataemia.

The clinical problem of hyperinsulinemic hypoglycemia and resultant infantile spasms

Hyperinsulinemic hypoglycemia (HH) is a cause of severe hypoglycemia in the newborn and infancy period and is associated with a high risk of neurologic handicap and epilepsy. Infantile spasms after exposure to HH is rare and has been described in only 1 previous report. We report the clinical, biochemical, and neurodevelopmental characteristics of 5 patients with neonatal-onset HH who subsequently developed infantile spasms. All 5 patients had neonatal-onset HH of varying severity and duration. These patients presented with the characteristic ictal pattern of spasms in clusters at a mean age of 6.6 months. Characteristic hypsarrhythmia was noted in only 3 of 5 patients. Structural abnormality was found in only 1 of 4 patients who underwent MRI of the brain. Infantile spasms responded to medical treatment in 3 patients, spasms in 1 patient were refractory to antiepileptic drugs, and treatment duration was insufficient for us to comment on the response in 1 patient. Developmental delay was evident in all of them. In conclusion neonatal HH of varying severity is associated with later (after a latent period) development of infantile spasms. The latent period before the onset of the spasms can be variable; hence, long-term neurodevelopmental follow-up (until 1 year of age) is necessary.

Congenital hyperinsulinism due to a compound heterozygous ABCC8 mutation with spontaneous resolution at eight weeks

BACKGROUND

Recessive inactivating mutations in ABCC8 and KCNJ11 (which encode the two subunits of the adenosine triphosphate-sensitive potassium (KATP) channels in beta-cells) are the most common cause of medically unresponsive congenital hyperinsulinism (CHI) which requires a near-total pancreatectomy.

METHODS/RESULTS

A patient born at term with marked macrosomia (5,900 g) presented at the age of 2 h with severe hyperinsulinaemic hypoglycaemia. He failed to respond to treatment with the KATP agonist, diazoxide. An (18F)DOPA-PET scan showed intense diffuse uptake of (18F)DOPA (consistent with diffuse disease) and genetic analysis of the ABCC8 gene confirmed a compound heterozygote missense ABCC8 mutation (R168C/S606T). However, unexpectedly in this patient the hyperinsulinaemic hypoglycaemia started to improve spontaneously at 7 weeks of age prior to planned pancreatic surgery.

CONCLUSIONS

This is the first report of a patient with clinically severe autosomal-recessive diffuse CHI due to a compound heterozygous ABCC8 mutation that has resulted in spontaneous resolution at such an early age. Compound heterozygote ABCC8 mutations result in complex interactions, and it is possible that this interaction may modify the potential disease pathogenesis. It is important that physicians are aware of this unusual outcome in order to avoid unnecessary early pancreatic surgery with potential life-long implications.

Diagnosis, management and therapeutic outcome in prepubertal Cushing's disease

OBJECTIVES

Cushing's disease (CD) in prepubertal children is very rare and presents important diagnostic and therapeutic challenges. We report experience of the management of this subpopulation of CD patients.

STUDY DESIGN/METHODS

Retrospective patient case note review.

RESULTS

Between 1985 and 2008, 17 prepubertal children (13M, 4F), aged 5.7-14.1 years presented to our centre for diagnosis and management of CD. All children had subnormal linear growth and excessive weight gain at presentation. A high proportion (85% of males, 75% of females) had evidence of excessive virilisation. Striae and hypertension were seen in 41% of patients. The investigation with highest sensitivity (100%) for CD was excessive increase of serum cortisol to i.v. CRH (mean increase 113%). Pituitary imaging performed in all the patients showed poor concordance with findings at surgery (31%). In contrast bilateral simultaneous inferior petrosal sinus sampling (BSIPSS), performed in 11/16 subjects showed a high correlation with surgical findings (91%). In 16 patients, transsphenoidal selective adenomectomy (TSS) achieved a cure rate of 44%. However, in the 11 patients who had pre-operative BSIPSS, the cure rate was 64%. Of the 16 patients, 9 patients who were not cured by TSS received external pituitary radiotherapy.

CONCLUSIONS

Prepubertal CD had distinctive features with increased frequency in males, abnormal auxology and excessive virilisation. The cortisol response to i.v. CRH administration was particularly exuberant and contributed to diagnosis. BSIPSS was much more helpful than pituitary imaging in localisation of the microadenoma and was associated with improved cure rate by TSS.

Antioxidant activity of Cassia auriculata flowers

The ethanol and methanol extracts of Cassia auriculata flowers were screened for antioxidant activity. The antioxidant activity was determined by an improved assay based on the decolorization of the radical monocation of 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging method. The ethanol and methanol extracts of C. auriculata flowers showed antioxidant activity in both assays.

Nitric oxide radical scavenging active components from Phyllanthus emblica L

An activity-directed fractionation and purification process was used to identify the nitric oxide (NO) scavenging components of Phyllanthus emblica. Dried fruit rind of P. emblica was extracted with methanol and then separated into hexane, ethyl acetate, and water fractions. Among these only the ethyl acetate phase showed strong NO scavenging activity in vitro, when compared with water and hexane phases. The ethyl acetate fraction was then subjected to separation and purification using Sephadex LH-20 chromatography. Five compounds showing strong NO scavenging activity were identified by spectral methods (1H NMR, 13C NMR, and MS) and by comparison with literature values to be Gallic acid, Methyl gallate, Corilagin, Furosin, and Geraniin. In addition, HPLC identification and quantification of isolated compounds were also performed. Gallic acid was found to be a major compound in the ethyl acetate extract and Geraniin showed highest NO scavenging activity among the isolated compounds.