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1.
Artículo en Inglés | MEDLINE | ID: mdl-38805311

RESUMEN

OBJECTIVE: To evaluate the impact of missed or late meal boluses (MLBs) on glycemic outcomes in children and adolescents with type 1 diabetes using automated insulin delivery (AID) systems. RESEARCH DESIGN AND METHODS: AID-treated (Tandem Control-IQ or Medtronic MiniMed 780G) children and adolescents (aged 6-21 years) from Stanford Medical Center and Steno Diabetes Center Copenhagen with ≥10 days of data were included in this two-center, binational, population-based, retrospective, 1-month cohort study. The primary outcome was the association between number of algorithm-detected MLBs and time in target glucose range (TIR; 70-180 mg/dL). RESULTS: The study included 189 children and adolescents (48% females with a mean ± SD age of 13 ± 4 years). Overall, the mean number of MLBs per day in the cohort was 2.2 ± 0.9. For each additional MLB per day, TIR decreased by 9.7%-points (95% CI 11.3; 8.1), and compared to the quartile with fewest MLBs (Q1), the quartile with most (Q4) had 22.9% less TIR (95% CI 27.2; 18.6). The age-, sex-, and treatment modality-adjusted probability of achieving a TIR of >70% in Q4 was 1.4% compared to 74.8% in Q1 (p<0.001). CONCLUSIONS: MLBs significantly impacted glycemic outcomes in AID-treated children and adolescents. The results emphasize the importance of maintaining a focus on bolus behavior to achieve higher TIR, and supports the need for further research in technological or behavioral support tools to handle missed and late meal boluses.

2.
J Surg Case Rep ; 2023(9): rjad516, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37724063

RESUMEN

Early complications after a laparoscopic sleeve gastrectomy (LSG) include bleeding, leaks, strictures and bowel obstructions. Patients post-LSG experience rapid but intended weight loss and may be on a restricted diet before and following surgery. Thus, many of these patients are in a malnourished state, placing them at a risk of developing potentially life-threatening refeeding syndrome (RFS). We describe the case of an 18-year-old female who developed RFS 2 weeks after LSG. We examine potential causes, review literature and discuss RFS pathophysiology as well as the guidelines that could help prevent RFS in bariatric surgery. Currently, not much is known about the risk of RFS in bariatric surgery and to our knowledge, this is the first report of RFS occurring in the early postoperative phase after LSG. A globally accepted definition of RFS should be established for guidelines to encompass wider patient groups.

3.
Space Sci Rev ; 219(3): 22, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37007705

RESUMEN

The objective of the Psyche Magnetometry Investigation is to test the hypothesis that asteroid (16) Psyche formed from the core of a differentiated planetesimal. To address this, the Psyche Magnetometer will measure the magnetic field around the asteroid to search for evidence of remanent magnetization. Paleomagnetic measurements of meteorites and dynamo theory indicate that a diversity of planetesimals once generated dynamo magnetic fields in their metallic cores. Likewise, the detection of a strong magnetic moment ( > 2 × 10 14 Am 2 ) at Psyche would likely indicate that the body once generated a core dynamo, implying that it formed by igneous differentiation. The Psyche Magnetometer consists of two three-axis fluxgate Sensor Units (SUs) mounted 0.7 m apart along a 2.15-m long boom and connected to two Electronics Units (EUs) located within the spacecraft bus. The Magnetometer samples at up to 50 Hz, has a range of ± 80 , 000 nT , and an instrument noise of 39 pT axis - 1 3 σ integrated over 0.1 to 1 Hz. The two pairs of SUs and EUs provide redundancy and enable gradiometry measurements to suppress noise from flight system magnetic fields. The Magnetometer will be powered on soon after launch and acquire data for the full duration of the mission. The ground data system processes the Magnetometer measurements to obtain an estimate of Psyche's dipole moment.

4.
Comput Biol Med ; 154: 106605, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36731362

RESUMEN

This paper validates a glucoregulatory model including glucagon receptors dynamics in the description of endogenous glucose production (EGP). A set of models from literature are selected for a head-to-head comparison in order to evaluate the role of glucagon receptors. Each EGP model is incorporated into an existing glucoregulatory model and validated using a set of clinical data, where both insulin and glucagon are administered. The parameters of each EGP model are identified in the same optimization problem, minimizing the root mean square error (RMSE) between the simulation and the clinical data. The results show that the RMSE for the proposed receptors-based EGP model was lower when compared to each of the considered models (Receptors approach: 7.13±1.71 mg/dl vs. 7.76±1.45 mg/dl (p=0.066), 8.45±1.38 mg/dl (p=0.011) and 8.99±1.62 mg/dl (p=0.007)). This raises the possibility of considering glucagon receptors dynamics in type 1 diabetes simulators.


Asunto(s)
Diabetes Mellitus Tipo 1 , Glucagón , Humanos , Glucosa , Receptores de Glucagón , Insulina , Glucemia
5.
Front Endocrinol (Lausanne) ; 14: 1073388, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36755913

RESUMEN

Objective: To assess the efficacy and safety of a dual-hormone (DH [insulin and glucagon]) closed-loop system compared to a single-hormone (SH [insulin only]) closed-loop system in adolescents with type 1 diabetes. Methods: This was a 26-hour, two-period, randomized, crossover, inpatient study involving 11 adolescents with type 1 diabetes (nine males [82%], mean ± SD age 14.8 ± 1.4 years, diabetes duration 5.7 ± 2.3 years). Except for the treatment configuration of the DiaCon Artificial Pancreas: DH or SH, experimental visits were identical consisting of: an overnight stay (10:00 pm until 7:30 am), several meals/snacks, and a 45-minute bout of moderate intensity continuous exercise. The primary endpoint was percentage of time spent with sensor glucose values below range (TBR [<3.9 mmol/L]) during closed-loop control over the 26-h period (5:00 pm, day 1 to 7:00 pm, day 2). Results: Overall, there were no differences between DH and SH for the following glycemic outcomes (median [IQR]): TBR 1.6 [0.0, 2.4] vs. 1.28 [0.16, 3.19]%, p=1.00; time in range (TIR [3.9-10.0 mmol/L]) 68.4 [48.7, 76.8] vs. 75.7 [69.8, 87.1]%, p=0.08; and time above range (TAR [>10.0 mmol/L]) 28.1 [18.1, 49.8] vs. 23.3 [12.3, 27.2]%, p=0.10. Mean ( ± SD) glucose was higher during DH than SH (8.7 ( ± 3.2) vs. 8.1 ( ± 3.0) mmol/L, p<0.001) but coefficient of variation was similar (34.8 ( ± 6.8) vs. 37.3 ( ± 8.6)%, p=0.20). The average amount of rescue carbohydrates was similar between DH and SH (6.8 ( ± 12.3) vs. 9.5 ( ± 15.4) grams/participant/visit, p=0.78). Overnight, TIR was higher, TAR was lower during the SH visit compared to DH. During and after exercise (4:30 pm until 7 pm) the SH configuration produced higher TIR, but similar TAR and TBR compared to the DH configuration. Conclusions: DH and SH performed similarly in adolescents with type 1 diabetes during a 26-hour inpatient monitoring period involving several metabolic challenges including feeding and exercise. However, during the night and around exercise, the SH configuration outperformed DH.


Asunto(s)
Diabetes Mellitus Tipo 1 , Insulina , Adolescente , Humanos , Masculino , Glucemia/metabolismo , Estudios Cruzados , Diabetes Mellitus Tipo 1/tratamiento farmacológico , Diabetes Mellitus Tipo 1/metabolismo , Glucosa , Método Simple Ciego , Femenino
6.
Annu Int Conf IEEE Eng Med Biol Soc ; 2022: 2240-2243, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-36086287

RESUMEN

In diabetes, it can become necessary to switch between pump- and pen-based insulin treatment. This switch involves a translation between rapid- and long-acting insulin analogues. In standard-of-care translation algorithms, a unit-to-unit conversion is applied. However, this simplification may not fit all individuals. In this paper, we investigate the correlation between dose-response to rapid- and long-acting insulin in the same individual, and compare the correlation across individuals. As a measure of dose-response, we estimate the insulin sensitivity in clinical data from 25 subjects with type 1 diabetes. For parameter estimation, we use maximum likelihood with a continuous-discrete extended Kalman filter and Bergman's minimal model. The results show a weak correlation between insulin sensitivity to rapid- and long-acting insulin across individuals. On this sparse data set, the analysis suggests that the standardized unit-to-unit translation between insulin analogues may not benefit all subjects.


Asunto(s)
Diabetes Mellitus Tipo 1 , Resistencia a la Insulina , Algoritmos , Diabetes Mellitus Tipo 1/tratamiento farmacológico , Humanos , Insulina , Insulina de Acción Prolongada
9.
Sci Data ; 8(1): 182, 2021 07 16.
Artículo en Inglés | MEDLINE | ID: mdl-34272376

RESUMEN

Inland fisheries and their freshwater habitats face intensifying effects from multiple natural and anthropogenic pressures. Fish harvest and biodiversity data remain largely disparate and severely deficient in many areas, which makes assessing and managing inland fisheries difficult. Expert knowledge is increasingly used to improve and inform biological or vulnerability assessments, especially in data-poor areas. Integrating expert knowledge on the distribution, intensity, and relative influence of human activities can guide natural resource management strategies and institutional resource allocation and prioritization. This paper introduces a dataset summarizing the expert-perceived state of inland fisheries at the basin (fishery) level. An electronic survey distributed to professional networks (June-September 2020) captured expert perceptions (n = 536) of threats, successes, and adaptive capacity to fisheries across 93 hydrological basins, 79 countries, and all major freshwater habitat types. This dataset can be used to address research questions with conservation relevance, including: demographic influences on perceptions of threat, adaptive capacities for climate change, external factors driving multi-stressor interactions, and geospatial threat assessments.


Asunto(s)
Explotaciones Pesqueras , Peces , Animales , Cambio Climático , Conservación de los Recursos Naturales , Actividades Humanas , Humanos , Conocimiento
10.
Int J Obes (Lond) ; 45(1): 235-246, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-32848203

RESUMEN

OBJECTIVES: Little is known about the long-term skeletal impact of bariatric procedures, particularly the increasingly commonly performed gastric sleeve surgery (GS). We examined bone density (BMD) change following three types of bariatric surgery Roux-en-Y gastric bypass (RYGB), GS and laparoscopic adjustable gastric banding (LAGB), compared with diet, over 36 months. METHODS: Non-randomized, prospective study of participants with severe obesity (n = 52), undergoing weight-loss interventions: RYGB (n = 7), GS (n = 21), LAGB (n = 11) and diet (n = 13). Measurements of calciotropic indices, gut hormones (fasting and post prandial) peptide YY (PYY), glucagon-like peptide 1 (GLP1) and adiponectin together with dual-X-ray absorptiometry and quantitative computed tomography scans were performed thorough the study. RESULTS: All groups lost weight during the first 12 months. Despite weight stability from 12 to 36 months and supplementation of calcium and vitamin D, there was progressive bone loss at the total hip (TH) over 36 months in RYGB -14% (95% CI: -12, -17) and GS -9% (95% CI: -7, -10). In RYGB forearm BMD also declined over 36 months -9% (95% CI: -6, -12) and LS BMD declined over the first 12 months -7% (95% CI: -3, -12). RYGB and GS groups experienced significantly greater bone loss until 36 months than LAGB and diet groups, which experienced no significant BMD loss. These bone losses remained significant after adjustment for weight loss and age. RYGB and GS procedures resulted in elevated postprandial PYY, adiponectin and bone turnover markers up to 36 months without such changes among LAGB and diet participants. CONCLUSIONS: RYGB and GS but not LAGB resulted in ongoing TH bone loss for three postoperative years. For RYGB, bone loss was also observed at LS and non-weight-bearing forearms. These BMD changes were independent of weight and age differences. We, therefore, recommend close monitoring of bone health following RYGB and GS surgeries.


Asunto(s)
Densidad Ósea/fisiología , Derivación Gástrica , Obesidad Mórbida/cirugía , Pérdida de Peso/fisiología , Adulto , Femenino , Derivación Gástrica/efectos adversos , Derivación Gástrica/estadística & datos numéricos , Humanos , Persona de Mediana Edad , Estudios Prospectivos
11.
Proc Natl Acad Sci U S A ; 117(47): 29419-29421, 2020 11 24.
Artículo en Inglés | MEDLINE | ID: mdl-33139565

RESUMEN

The COVID-19 pandemic has led to environmental recovery in some ecosystems from a global "anthropause," yet such evidence for natural resources with extraction or production value (e.g., fisheries) is limited. This brief report provides a data-driven global snapshot of expert-perceived impacts of COVID-19 on inland fisheries. We distributed an online survey assessing perceptions of inland fishery pressures in June and July 2020 to basin-level inland fishery experts (i.e., identified by the Food and Agriculture Organization of the United Nations across the global North and South); 437 respondents from 79 countries addressed 93 unique hydrological basins, accounting for 82.1% of global inland fish catch. Based on the responses analyzed against extrinsic fish catch and human development index data, pandemic impacts on inland fisheries 1) add gradation to the largely positive environmental narrative of the global pandemic and 2) identify that basins of higher provisioning value are perceived to experience greater fishery pressures but may have limited compensatory capacity to mitigate COVID-19 impacts along with negative pressures already present.


Asunto(s)
COVID-19/economía , Explotaciones Pesqueras/economía , Pandemias/economía , COVID-19/epidemiología , Explotaciones Pesqueras/estadística & datos numéricos , Inseguridad Alimentaria , Humanos
12.
Food Microbiol ; 90: 103468, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32336359

RESUMEN

Listeria monocytogenes is a significant concern for the produce industry; however, there is limited information to support the practical decision-making to mitigate this risk. This study investigated the prevalence of Listeria spp. and L. monocytogenes in seven produce handling and processing (PHP) facilities in the Pacific Northwest. PHP facilities were defined as facilities that receive raw agricultural commodities and further handle, pack, wash, or process prior to distribution into the retail sector. Environmental swabs (n = 50/facility) were collected in high-risk areas (e.g., near raw product entry points) from seven PHP facilities over two visits. Listeria spp. were isolated using modified ISO 11290-1 method and speciated with Microgen® Listeria-ID. Listeria spp., including L. monocytogenes, were found in 5/7 PHP. Prevalence of Listeria spp. ranged from 2% to 26% in these five facilities. Drains, entry areas, and portable equipment consistently tested positive for Listeria spp. during active production. Two additional sampling rounds (n = 50/round) were conducted in the highest prevalence facility (Facility #1). Overall, Listeria spp. were detected in 44/150 (29.3%) swabs collected from Facility #1. This study demonstrated the high prevalence of Listeria spp. near raw product entry points across PHP facilities.


Asunto(s)
Contaminación de Equipos/estadística & datos numéricos , Manipulación de Alimentos , Microbiología de Alimentos/métodos , Industria de Procesamiento de Alimentos , Listeria/aislamiento & purificación , Listeria/clasificación , Noroeste de Estados Unidos , Prevalencia
13.
Diabetes Technol Ther ; 21(5): 295-302, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-30994362

RESUMEN

Background: The aim was to compare the accuracy of the Dexcom® G4 Platinum continuous glucose monitor (CGM) sensor inserted on the upper arm and the abdomen in adults. Methods: Fourteen adults with type 1 diabetes wore two CGMs, one placed on the upper arm and one placed on the abdomen. Three in-clinic visits of 5 h with YSI (2300 STAT, Yellow Springs Instrument) measurements as comparator were performed. Each visit was followed by 4 days with seven-point self-monitoring of blood glucose (SMBG) in free-living conditions. Accuracy analyses on the paired CGM-YSI and CGM-SMBG measurements of the two CGM sensors were performed. Results: Using YSI as comparator, the overall Mean Absolute Relative Difference (MARD) for the CGMabd was 12.3% and CGMarm was 12.0%. The percentage of the CGM measurements in zone A of Clarke error grid analysis for the CGMabd was 85.6% and CGMarm was 86.0%. The hypoglycemia sensitivity for the CGMabd and CGMarm was 69.3%. Using SMBG as comparator, the overall MARD for the CGMabd was 12.5% and CGMarm was 12.0%. The percentage of the CGM measurements in zone A for the CGMabd was 84.1% and the CGMarm was 85.0%. The hypoglycemia sensitivity for the CGMabd was 60.0% and the CGMarm was 71.1%. All the P-values from the comparisons between the accuracy of CGMabd and CGMarm were >0.05. Conclusion: The accuracy of a Dexcom G4 Platinum CGM sensor placed on the upper arm was not different from the accuracy of the sensor placed on the abdomen in adults with type 1 diabetes.


Asunto(s)
Automonitorización de la Glucosa Sanguínea/métodos , Glucemia/análisis , Diabetes Mellitus Tipo 1/sangre , Abdomen , Adulto , Anciano , Brazo , Automonitorización de la Glucosa Sanguínea/instrumentación , Femenino , Humanos , Sistemas de Infusión de Insulina , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Adulto Joven
14.
J Process Control ; 80: 202-210, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32831483

RESUMEN

This paper presents an individualized Ensemble Model Predictive Control (EnMPC) algorithm for blood glucose (BG) stabilization and hypoglycemia prevention in people with type 1 diabetes (T1D) who exercise regularly. The EnMPC formulation can be regarded as a simplified multi-stage MPC allowing for the consideration of N en scenarios gathered from the patient's recent behavior. The patient's physical activity behavior is characterized by an exercise-specific input signal derived from the deconvolution of the patient's continuous glucose monitor (CGM), accounting for known inputs such as meal, and insulin pump records. The EnMPC controller was tested in a cohort of in silico patients with representative inter-subject and intra-subject variability from the FDA-accepted UVA/Padova simulation platform. Results show a significant improvement on hypoglycemia prevention after 30 min of mild to moderate exercise in comparison to a similarly tuned baseline controller (rMPC); with a reduction in hypoglycemia occurrences (< 70 mg/dL), from 3.08% ± 3.55 with rMPC to 0.78% ± 2.04 with EnMPC (P < 0.05).

15.
Nature ; 561(7721): 76-78, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-30185957

RESUMEN

The Juno spacecraft, which is in a polar orbit around Jupiter, is providing direct measurements of the planet's magnetic field close to its surface1. A recent analysis of observations of Jupiter's magnetic field from eight (of the first nine) Juno orbits has provided a spherical-harmonic reference model (JRM09)2 of Jupiter's magnetic field outside the planet. This model is of particular interest for understanding processes in Jupiter's magnetosphere, but to study the field within the planet and thus the dynamo mechanism that is responsible for generating Jupiter's main magnetic field, alternative models are preferred. Here we report maps of the magnetic field at a range of depths within Jupiter. We find that Jupiter's magnetic field is different from all other known planetary magnetic fields. Within Jupiter, most of the flux emerges from the dynamo region in a narrow band in the northern hemisphere, some of which returns through an intense, isolated flux patch near the equator. Elsewhere, the field is much weaker. The non-dipolar part of the field is confined almost entirely to the northern hemisphere, so there the field is strongly non-dipolar and in the southern hemisphere it is predominantly dipolar. We suggest that Jupiter's dynamo, unlike Earth's, does not operate in a thick, homogeneous shell, and we propose that this unexpected field morphology arises from radial variations, possibly including layering, in density or electrical conductivity, or both.

16.
Basic Clin Pharmacol Toxicol ; 122(3): 322-330, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-28922582

RESUMEN

Hypoglycaemia remains the main limiting factor in type 1 diabetes management. We developed an insulin-dependent glucagon dosing regimen for treatment of mild hypoglycaemia based on simulations. A validated glucose-insulin-glucagon model was used to describe seven virtual patients with insulin pump-treated type 1 diabetes. In each simulation, one of ten different and individualized subcutaneous insulin boluses was administered to decrease plasma glucose (PG) from 7.0 to ≤3.9 mmol/l. Insulin levels were estimated as ratio of actual to baseline serum insulin concentration (se/ba-insulin), insulin on board (IOB) or percentage of IOB to total daily insulin dose (IOB/TDD). Insulin bolus sizes were chosen to provide pre-defined insulin levels when PG reached 3.9 mmol/l, where one of 17 subcutaneous glucagon boluses was administered. Optimum glucagon bolus to treat mild hypoglycaemia at varying insulin levels was the lowest dose that in most patients caused PG peak between 5.0 and 10.0 mmol/l and sustained PG ≥ 3.9 mmol/l for 2 hr after the bolus. PG response to glucagon declined with increasing insulin levels. The glucagon dose to optimally treat mild hypoglycaemia depended exponentially on insulin levels, regardless of how insulin was estimated. A 125-µg glucagon dose was needed to optimally treat mild hypoglycaemia when insulin levels were equal to baseline levels. In contrast, glucagon doses >500 µg were needed when se/ba-insulin >2.5, IOB >2.0 U or IOB/TDD >6%. Although the proposed model-based glucagon regimen needs confirmation in clinical trials, this is the first attempt to develop an insulin-dependent glucagon dosing regimen for treatment of insulin-induced mild hypoglycaemia in patients with type 1 diabetes.


Asunto(s)
Diabetes Mellitus Tipo 1/tratamiento farmacológico , Glucagón/administración & dosificación , Terapia de Reemplazo de Hormonas , Hipoglucemia/tratamiento farmacológico , Hipoglucemiantes/administración & dosificación , Insulina/administración & dosificación , Modelos Biológicos , Adulto , Glucemia/análisis , Biología Computacional , Simulación por Computador , Diabetes Mellitus Tipo 1/sangre , Relación Dosis-Respuesta a Droga , Esquema de Medicación , Monitoreo de Drogas , Sistemas Especialistas , Femenino , Glucagón/efectos adversos , Glucagón/uso terapéutico , Terapia de Reemplazo de Hormonas/efectos adversos , Humanos , Hipoglucemia/sangre , Hipoglucemia/inducido químicamente , Hipoglucemiantes/efectos adversos , Hipoglucemiantes/farmacocinética , Hipoglucemiantes/uso terapéutico , Inyecciones Subcutáneas , Insulina/efectos adversos , Insulina/farmacocinética , Insulina/uso terapéutico , Sistemas de Infusión de Insulina/efectos adversos , Persona de Mediana Edad , Adulto Joven
17.
J Pharmacokinet Pharmacodyn ; 44(5): 477-489, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28831695

RESUMEN

Effective mathematical modelling of continuous subcutaneous infusion pharmacokinetics should aid understanding and control in insulin therapy. Thorough analysis of candidate model performance is important for selecting the appropriate models. Eight candidate models for insulin pharmacokinetics included a range of modelled behaviours, parameters and complexity. The models were compared using clinical data from subjects with type 1 diabetes with continuous subcutaneous insulin infusion. Performance of the models was compared through several analyses: R2 for goodness of fit; the Akaike Information Criterion; a bootstrap analysis for practical identifiability; a simulation exercise for predictability. The simplest model fit poorly to the data (R2 = 0.53), had the highest Akaike score, and worst prediction. Goodness of fit improved with increasing model complexity (R2 = 0.85-0.92) but Akaike scores were similar for these models. Complexity increased practical non-identifiability, where small changes in the dataset caused large variation (CV > 10%) in identified parameters in the most complex models. Best prediction was achieved in a relatively simple model. Some model complexity was necessary to achieve good data fit but further complexity introduced practical non-identifiability and worsened prediction capability. The best model used two linear subcutaneous compartments, an interstitial and plasma compartment, and two identified variables for interstitial clearance and subcutaneous transfer rate. This model had optimal performance trade-off with reasonable fit (R2 = 0.85) and parameterisation, and best prediction and practical identifiability (CV < 2%).


Asunto(s)
Insulina Aspart/farmacocinética , Modelos Cardiovasculares , Adulto , Diabetes Mellitus Tipo 1/sangre , Femenino , Humanos , Infusiones Subcutáneas , Insulina Aspart/administración & dosificación , Insulina Aspart/sangre , Masculino , Persona de Mediana Edad , Adulto Joven
18.
J Diabetes Sci Technol ; 11(6): 1101-1111, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-28654314

RESUMEN

BACKGROUND: Currently, no consensus exists on a model describing endogenous glucose production (EGP) as a function of glucagon concentrations. Reliable simulations to determine the glucagon dose preventing or treating hypoglycemia or to tune a dual-hormone artificial pancreas control algorithm need a validated glucoregulatory model including the effect of glucagon. METHODS: Eight type 1 diabetes (T1D) patients each received a subcutaneous (SC) bolus of insulin on four study days to induce mild hypoglycemia followed by a SC bolus of saline or 100, 200, or 300 µg of glucagon. Blood samples were analyzed for concentrations of glucagon, insulin, and glucose. We fitted pharmacokinetic (PK) models to insulin and glucagon data using maximum likelihood and maximum a posteriori estimation methods. Similarly, we fitted a pharmacodynamic (PD) model to glucose data. The PD model included multiplicative effects of insulin and glucagon on EGP. Bias and precision of PD model test fits were assessed by mean predictive error (MPE) and mean absolute predictive error (MAPE). RESULTS: Assuming constant variables in a subject across nonoutlier visits and using thresholds of ±15% MPE and 20% MAPE, we accepted at least one and at most three PD model test fits in each of the seven subjects. Thus, we successfully validated the PD model by leave-one-out cross-validation in seven out of eight T1D patients. CONCLUSIONS: The PD model accurately simulates glucose excursions based on plasma insulin and glucagon concentrations. The reported PK/PD model including equations and fitted parameters allows for in silico experiments that may help improve diabetes treatment involving glucagon for prevention of hypoglycemia.


Asunto(s)
Glucemia/efectos de los fármacos , Simulación por Computador , Diabetes Mellitus Tipo 1/tratamiento farmacológico , Glucagón/administración & dosificación , Hipoglucemia/tratamiento farmacológico , Hipoglucemiantes/administración & dosificación , Insulina/administración & dosificación , Modelos Biológicos , Adulto , Biomarcadores/sangre , Glucemia/metabolismo , Diabetes Mellitus Tipo 1/sangre , Diabetes Mellitus Tipo 1/diagnóstico , Cálculo de Dosificación de Drogas , Femenino , Glucagón/efectos adversos , Glucagón/farmacocinética , Humanos , Hipoglucemia/sangre , Hipoglucemia/inducido químicamente , Hipoglucemia/diagnóstico , Hipoglucemiantes/efectos adversos , Hipoglucemiantes/farmacocinética , Inyecciones Subcutáneas , Insulina/efectos adversos , Insulina/farmacocinética , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Resultado del Tratamiento , Adulto Joven
19.
J Diabetes Sci Technol ; 11(1): 29-36, 2017 01.
Artículo en Inglés | MEDLINE | ID: mdl-27613658

RESUMEN

BACKGROUND: Bolus calculators help patients with type 1 diabetes to mitigate the effect of meals on their blood glucose by administering a large amount of insulin at mealtime. Intraindividual changes in patients physiology and nonlinearity in insulin-glucose dynamics pose a challenge to the accuracy of such calculators. METHOD: We propose a method based on a continuous-discrete unscented Kalman filter to continuously track the postprandial glucose dynamics and the insulin sensitivity. We augment the Medtronic Virtual Patient (MVP) model to simulate noise-corrupted data from a continuous glucose monitor (CGM). The basal rate is determined by calculating the steady state of the model and is adjusted once a day before breakfast. The bolus size is determined by optimizing the postprandial glucose values based on an estimate of the insulin sensitivity and states, as well as the announced meal size. Following meal announcements, the meal compartment and the meal time constant are estimated, otherwise insulin sensitivity is estimated. RESULTS: We compare the performance of a conventional linear bolus calculator with the proposed bolus calculator. The proposed basal-bolus calculator significantly improves the time spent in glucose target ( P < .01) compared to the conventional bolus calculator. CONCLUSION: An adaptive nonlinear basal-bolus calculator can efficiently compensate for physiological changes. Further clinical studies will be needed to validate the results.


Asunto(s)
Glucemia/análisis , Diabetes Mellitus Tipo 1/tratamiento farmacológico , Hipoglucemiantes/administración & dosificación , Insulina/administración & dosificación , Dinámicas no Lineales , Diabetes Mellitus Tipo 1/sangre , Humanos , Interfaz Usuario-Computador
20.
Obes Surg ; 26(12): 2936-2943, 2016 12.
Artículo en Inglés | MEDLINE | ID: mdl-27146660

RESUMEN

BACKGROUND: Laparoscopic sleeve gastrectomy (LSG) as a single-stage procedure has shown to be effective in achieving significant weight loss and resolving obesity-related co-morbidities. However, its nutrition consequences have not been extensively explored. This study aims to investigate weight loss and evolution of nutritional deficiencies in a group of patients 3 years post LSG. METHODS: Retrospective data of a group of patients, 3 years following LSG as a stand-alone procedure was collected. Data included anthropometry, nutritional markers (hemoglobin, iron studies, folate, calcium, iPTH, vitamins D, and B12), and compliancy with supplementations. RESULTS: Ninety-one patients (male/female; 28:63), aged 51.9 ± 11.4 years with a BMI of 42.8 ± 6.1 kg/m2 were identified to be 3 years post LSG. Percentage of weight loss at 1 and 3 years post-operatively was 29.8 ± 7.0 and 25.9 ± 8.8 %, respectively. Pre-operatively, the abnormalities included low hemoglobin (4 %), ferritin (6 %), vitamin B12 (1 %), vitamin D (46 %), and elevated iPTH (25 %). At 3 years post-operatively, the abnormal laboratory values included low hemoglobin (14 % females, P = 0.021), ferritin (24 %, P = 0.011), vitamin D (20 %, P = 0.018), and elevated iPTH (17 %, P = 0.010). Compliancy with multivitamin supplementation was noted in 66 % of patients. CONCLUSION: In these patients, LSG resulted in pronounced weight loss at 1 year post-operatively, and most of this was maintained at 3 years. Nutritional deficiencies are prevalent among patients prior to bariatric surgery. These deficiencies may persist or exacerbate post-operatively. Routine nutrition monitoring and supplementations are essential to prevent and treat these deficiencies.


Asunto(s)
Desnutrición/etiología , Obesidad Mórbida/cirugía , Pérdida de Peso , Adulto , Anciano , Femenino , Gastrectomía/métodos , Humanos , Laparoscopía/métodos , Masculino , Desnutrición/sangre , Persona de Mediana Edad , Complicaciones Posoperatorias/sangre , Complicaciones Posoperatorias/etiología , Estudios Retrospectivos
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