The Impact of Parental Electronic Health Literacy on Disease Management and Outcomes in Pediatric Type 1 Diabetes Mellitus: Cross-Sectional Clinical Study

BACKGROUND

Despite the growing uptake of smart technologies in pediatric type 1 diabetes mellitus (T1DM) care, little is known about caregiving parents' skills to deal with electronic health information sources.

OBJECTIVE

We aimed to assess the electronic health literacy of parents caring for children with T1DM and investigate its associations with disease management and children's outcomes.

METHODS

A cross-sectional survey was performed involving 150 parent-child (8-14 years old with T1DM) dyads in a university pediatric diabetology center. Parents' electronic health literacy (eHealth Literacy Scale [eHEALS]), general health literacy (Chew questionnaire and Newest Vital Sign [NVS]), and attitudes toward T1DM care (Parental Self-Efficacy Scale for Diabetes Management [PSESDM] and Hypoglycemia Fear Survey [HFS]) were investigated. Children's treatment, HbA1c level, and quality of life (Pediatric Quality of Life Inventory Diabetes Module [PedsQL Diab] and EQ-5D-Y-3L) were assessed. Multiple linear regression analysis was performed to investigate the determining factors of 6-month average HbA1c.

RESULTS

Of the 150 children, 38 (25.3%) used a pen, 55 (36.7%) used a pen plus a sensor, 6 (4.0%) used an insulin pump, and 51 (34.0%) used an insulin pump plus a sensor. Parents' average eHEALS score (mean 31.2, SD 4.9) differed significantly by educational level (P=.04) and the children's treatment (P=.005), being the highest in the pump + sensor subgroup. The eHEALS score showed significant Pearson correlations with the Chew score (r=-0.45; P<.001), NVS score (r=0.25; P=.002), and PSESDM score (r=0.35; P<.001) but not with the children's HbA1c (r=-0.143; P=.08), PedsQL Diab (r=-0.0002; P>.99), and EQ-5D-Y-3L outcomes (r=-0.13; P=.12). Regression analysis revealed significant associations of the child's HbA1c level with sex (β=0.58; P=.008), treatment modality (pen + sensor: β=-0.66; P=.03; pump + sensor: β=-0.93; P=.007), and parents' self-efficacy (PSESDM; β=-0.08; P=.001).

CONCLUSIONS

Significantly higher parental electronic health literacy was found in T1DM children using a glucose sensor. The electronic health literacy level was associated with parents' diabetes management attitude but not with the child's glycemic control. Studies further investigating the role of parental electronic health literacy in T1DM children managed at different levels of care and the local context are encouraged.

[The role of cognitive emotion regulation in disordered eating among chronically ill adolescents]

Bevezetés: A krónikus betegségek evészavartünetekkel való társulása fokozott figyelmet igényel a súlyos szövődmények lehetősége és a mortalitási rizikó növekedése miatt. Az evészavarok és a szubklinikai evészavarok maladaptív érzelemszabályozással járnak együtt, melyek kiváltó és fenntartó tényezői is lehetnek a betegségnek. Ismereteink szerint a gyulladásos bélbetegséggel és 1-es típusú diabetesszel élő serdülők kognitív érzelemszabályozásának szerepét az evészavartüneteikben ez idáig még nem vizsgálták. Célkitűzés: 14 és 18 év közötti serdülők körében elemeztük a kognitív érzelemszabályozás és az evészavartünetek kapcsolatát, különös tekintettel az 1-es típusú diabetesben és gyulladásos bélbetegségben érintett fiatalokra. Kutatásunk arra irányult, hogy krónikus betegek csoportjaiban kimutatható-e egyes kognitív érzelemszabályozó stratégiák szerepe az evészavartünetekben. Módszer: Vizsgálatunkban 300 serdülő töltötte ki tájékozott beleegyezés után a Kognitív Érzelemreguláció Kérdőívet és a Pszichopatológiai Tünetlista Gyermekek és Serdülők Számára kérdőívet. A négy vizsgálati csoportot 157, testileg egészséges serdülő, 51, gyulladásos bélbetegség diagnózisával élő serdülő, 61, 1-es típusú diabetes diagnózisú serdülő és 31, anorexia nervosa diagnózissal rendelkező serdülő alkotta. Eredmények: Vizsgálatunk eredményei alapján a gyulladásos bélbetegséggel élő fiatalok esetében a ruminatio és a pozitív átértékelés, az 1-es típusú diabetes diagnózisú serdülőknél pedig az önvád és a ruminatio közvetett úton szignifikáns kapcsolatban állt az evészavartünetekkel. Megbeszélés: Eredményeink arra utalnak, hogy a kognitív érzelemszabályozó stratégiák a vizsgált krónikus betegséggel élő serdülők körében indirekt módon kapcsolatban állnak az evészavartünetekkel. Az önvád és ruminatio negatív érzelemszabályozó stratégiák gyakoribb alkalmazása növeli az evészavartünetek előfordulását, ugyanakkor kisebb mértékű használatuk kevesebb evészavartünettel jár együtt. A pozitív átértékelés nagyobb mértékű alkalmazása kevesebb evészavartünettel jár együtt. Következtetés: A kognitív érzelemszabályozó stratégiák vizsgálatát és fejlesztését javasoljuk beépíteni a krónikus beteg serdülők komplex ellátásába. Orv Hetil. 2023; 164(48): 1895–1903.

Thyroid disturbances after COVID-19 and the effect of vaccination in children: a prospective tri-center registry analysis

Rapidly evolving clinical data suggest that the novel coronavirus (SARS-CoV-2) and vaccination against COVID-19 might be associated with thyroid disturbances. However, studies remain limited among the pediatric population. Our aim was to assess the prevalence and permanence of thyroid autoimmunity (TA) and dysfunction in children after an acute infection and its potential association with vaccination. A prospective, multicenter registry analysis was performed among 458 children (mean age: 12.4 ± 3,8 years, 45.4% male) with preceding COVID-19. Patient inclusion lasted from 24th March, 2021 to 23rd March, 2022 at three pediatric outpatient facilities at Semmelweis University, Budapest. Primary outcomes were the rate of thyroid disturbances assessed by laboratory parameters (thyroid function tests, antithyroglobulin [ATG] and anti-thyroid peroxidase [ATPO] antibodies) and thyroid ultrasound. TA rate among vaccinated and unvaccinated children was determined. Children with newly diagnosed thyroid alterations were followed up for 12.7 ± 4.3 months. Six children had previous thyroid disease. Out of 452 children, 30 cases (6.6%) of newly diagnosed TA (six of them had abnormal thyroid-stimulating hormone [TSH] levels) and eight cases (1.8%) of isolated TSH elevation were observed. Ultrasound-proven autoimmune thyroiditis (AIT) was 4.0%. No association was found between COVID-19 vaccination and thyroid autoimmunity (χ2(1,N = 452) = 0.138, p = 0.815). Among children with TA, 73.3% had long-lasting alterations.  Conclusion: Vaccination had no effect on the prevalence of TA. Until further controlled studies state otherwise, children with preceding COVID-19 might benefit from thyroid screening. What is Known: • Numerous case reports implicate that coronavirus disease-2019 (COVID-19) and vaccination against SARS-CoV-2 can be responsible for thyroid disturbances. • Thyroid alterations discovered during acute COVID-19 tend to cease by time and only incidental thyroid autoimmunity (TA) is diagnosed after COVID-19. In adults, no increase in vaccine-related hyper- or hypothyroidism was found. What is New: • TA rate after COVID-19 vaccination among children was not increased. TA had no role in long COVID syndrome. • We discovered a considerable rate of TA (6.6%) and ultrasound-proven autoimmune thyroiditis (AIT) (4.0%) after SARS-CoV-2 infection, and the majority of these alterations remained positive after 6 months.

The Predictive Role of Cognitive Emotion Regulation of Adolescents with Chronic Disease and Their Parents in Adolescents' Quality of Life: A Pilot Study

BACKGROUND

The purpose of this study was to investigate cognitive emotion regulation in adolescents with chronic illness and their parents.

METHODS

Eighty-five young people (mean = 15.86 years, standard deviation = ± 1.42, girls 65.88%) with chronic illnesses (inflammatory bowel disease n = 40 or type 1 diabetes n = 45), and their parents (mean = 46.06 years, 87.06% mother) completed the Cognitive Emotion Regulation Questionnaire (CERQ) for themselves and the Inventory of Quality of Life in Children and Adolescents (ILC) questionnaire adolescent and parent version. We conducted two hierarchical linear regression analyses with "enter" method. The CERQ scales and the diagnosis of chronic disease were chosen as independent variables, and the total ILC score in the first analysis and the ILC proxy score in the second analysis were chosen as dependent variables.

RESULTS

Among adolescents, cognitive emotion regulation strategies such as self-blame, positive reappraisal, and catastrophizing have been proven to be predictors of their own quality of life; however, parental self-blame was also found to be a predictor of adolescents' quality of life. Parental rumination and positive refocusing have been shown to be predictors of how parents rate their child's quality of life.

CONCLUSIONS

The present study sheds light on cognitive emotion regulation strategies in adolescents with chronic illness and their parents that have a significant impact on the development of young people's quality of life.

Anti-SARS-CoV-2 Seropositivity Among Children With Newly Diagnosed Type 1 Diabetes Mellitus: A Case-Control Study

A sudden increase in the number of children with newly diagnosed type 1 diabetes mellitus (T1DM) was experienced during the third wave of COVID-19 epidemic in Hungary. The newly diagnosed T1DM patients had a significantly higher rate of anti-SARS-CoV-2 positivity as compared to prevalent T1DM children [OR (95% CI) 3.74 (1,08,13.55); P=0.04]. The relationship between SARS-CoV-2 infection and diabetes needs to be investigated further.

Transitional elevation of anti-tissue transglutaminase antibodies in children with type 1 diabetes mellitus without coeliac disease

Összefoglaló. Bevezetés: Az 1-es típusú diabetes mellitus és a coeliakia gyakori társulása jól ismert. Néhány tanulmány beszámol átmeneti antitranszglutamináz-emelkedésről 1-es típusú diabeteses betegekben, akiknél az emelkedett antitestszint gluténmentes diéta bevezetése nélkül normalizálódik. Célkitűzés: Kutatásunk során az átmeneti antitranszglutamináz-emelkedés gyakoriságának meghatározását tűztük ki célul. További célunk volt a coeliakia gyakoriságának megállapítása 1-es típusú diabetesszel gondozott betegeink között. Módszer: A Semmelweis Egyetem I. Gyermekgyógyászati Klinikáján 1-es típusú diabetesszel gondozott betegeket vontuk be vizsgálatunkba (238 lány, 265 fiú, medián [IR] életkor az 1-es típusú diabetes diagnózisakor: 7,83 [4,67-11] év). Vizsgáltuk a jelenség időbeli megjelenését, az emelkedés mértékét, gyakoriságát és az antitest típusát. Leíró statisztikai módszereket és khi-négyzet-próbát alkalmaztunk. Eredmények: A vizsgált populációban a coeliakia gyakorisága 12,52%. Átmeneti antitranszglutamináztiter-emelkedést 48 gyermeknél (10,9%) észleltünk. Összesen 71-szer mértünk átmeneti antitranszglutamináz-emelkedést. A gyermekek közül 34 esetben (70,83%) egyszer fordult elő emelkedést mutató antitest, a többi betegnél 2-8 alkalommal. Gyakrabban tapasztaltunk izolált IgA-típusú emelkedést, mint izolált IgG-típusút (54 vs. 5). Következtetés: Az átmeneti antitranszglutamináz-emelkedés gyakorisága magas, összevethető a valódi coeliakiás csoporttal. Kutatásunk alátámasztja a nemzetközi ajánlást, miszerint mérsékelt mértékű antitranszglutamináz-emelkedés esetén, tünetmentes 1-es típusú diabetesszel gondozott betegben a gluténfogyasztás folytatása és az antitestszintek gyakori kontrollja javasolt. Orv Hetil. 2021; 162(48): 1924-1930.

SUMMARY

INTRODUCTION

The frequent association of type 1 diabetes mellitus with coeliac disease is well known. Development of transitional elevation of anti-tissue transglutaminase antibodies in the diagnosis of type 1 diabetes is reported in some studies. In these cases, the anti-tissue transglutaminase antibodies returned to normal without gluten-free diet.

OBJECTIVE

Our aim was to assess the frequency of transitional elevation of anti-tissue transglutaminase in our type 1 diabetes patients. We aimed to investigate the prevalence of coeliac disease in patients with type 1 diabetes.

METHOD

Patients with type 1 diabetes at the Ist Department of Paediatrics, Semmelweis University, were enrolled in the study (238 girls, 265 boys; the median age at the time of type 1 diabetes diagnosis was 7.83 [4.67-11] years). Descriptive statistical analysis was done and the time of appearance, extent, frequency and type of elevated anti-tissue transglutaminase antibodies were examined.

RESULTS

The proportion of children with diagnosed coeliac disease was 12.52%. We detected transitional anti-tissue transglutaminase elevation in 48 cases (10.9%). Temporarily elevated antibody levels were measured 71 times. In 34 children (70.83%), the temporary elevation occured once, while in the others, antibody levels became positive 2-8 times. The elevation of the IgA antibody was more frequent than the elevation of the IgG antibody (54 vs. 5).

CONCLUSION

The frequency of temporary elevated anti-tissue transglutaminase levels is considered high. Our study confirms the recommendation that in the case of moderate anti-tissue transglutaminase levels with lack of clinical symptoms, control antibody measurement is necessary with ongoing gluten consumption. Orv Hetil. 2021; 162(48): 1924-1930.

Starving for independence. Anorexia nervosa in an adolescent with type 1 diabetes

Összefoglaló. Az 1-es típusú diabetes mellitus (T1DM-) betegek körében az evészavarok előfordulása az átlagpopulációhoz képest körülbelül kétszeresre tehető. Ez a komorbiditás különösen veszélyes mind a magas mortalitási rizikó, mind a súlyos szövődmények lehetősége miatt. Az evészavarban szenvedő, T1DM-mel élő gyermekek és fiatalok hatékony kezelése a diabetológusok, pszichiáterek, pszichológusok, nővérek és dietetikusok összehangolt munkájával valósítható meg. Közleményünkben egy 14,5 éves, T1DM-mel élő, anorexia nervosával diagnosztizált páciensünk multidiszciplináris terápiáját mutatjuk be, kiemelve a különböző szakemberek együttműködésének főbb metszéspontjait. A szoros diabetológiai gondozással párhuzamosan az anorexia nervosa terápiájában a protokollok ajánlásaival megegyezően családterápiát és kognitív viselkedésterápiás elemekkel bővített egyéni terápiát alkalmaztunk. A terápiás folyamat összesen 18 hónapig tartott. Esetünk korábban le nem írt diabetológiai érdekessége, hogy a számottevő súlycsökkenéssel párhuzamosan betegünk inzulinigénye a töredékére csökkent, ami jelentős mértékben érintette a bazálisinzulin-szükségletet is. Orv Hetil. 2021; 162(33): 1341-1346. Summary. The incidence of eating disorders is approximately twice as high in type 1 diabetes mellitus (T1DM) compared to the general population. Comorbidity is related to potentially severe organ complications and consequently higher mortality risk. The effective treatment of eating disorders in T1DM is provided by the teamwork of diabetologists, psychiatrists, psychologists, nurses and dietitians. The purpose of this paper is to present the multidisciplinary treatment of a 14.5-year-old adolescent with T1DM and diagnosed with anorexia nervosa, focusing on the cooperation of the professionals. In line with the current guidelines, both family therapy and cognitive behavioral therapy-informed individual psychotherapy were applied beside the strict diabetes control. Her therapy process lasted 18 months. The unusual diabetological aspect of our case is that the significant weight loss was associated with highly decreased insulin requirement affecting also the basal insulin requirements. Orv Hetil. 2021; 162(33): 1341-1346.

A Comprehensive Analysis of Hungarian MODY Patients-Part I: Gene Panel Sequencing Reveals Pathogenic Mutations in HNF1A, HNF1B, HNF4A, ABCC8 and INS Genes

Maturity-onset diabetes of the young (MODY) has about a dozen known causal genes to date, the most common ones being HNF1A, HNF4A, HNF1B and GCK. The phenotype of this clinically and genetically heterogeneous form of diabetes depends on the gene in which the patient has the mutation. We have tested 450 Hungarian index patients with suspected MODY diagnosis with Sanger sequencing and next-generation sequencing and found a roughly 30% positivity rate. More than 70% of disease-causing mutations were found in the GCK gene, about 20% in the HNF1A gene and less than 10% in other MODY-causing genes. We found 8 pathogenic and 9 likely pathogenic mutations in the HNF1A gene in a total of 48 patients and family members. In the case of HNF1A-MODY, the recommended first-line treatment is low dose sulfonylurea but according to our data, the majority of our patients had been on unnecessary insulin therapy at the time of requesting their genetic testing. Our data highlights the importance of genetic testing in the diagnosis of MODY and the establishment of the MODY subtype in order to choose the most appropriate treatment.

Celiac disease in children with type 1 diabetes varies around the world: An international, cross-sectional study of 57 375 patients from the SWEET registry

BACKGROUND

Children with type 1 diabetes (T1D) are at much higher risk of developing celiac disease (CD) than the general population. The aim of the study was to assess the prevalence and differences in clinical presentation of CD in T1D in different regions of the world.

METHODS

This study is based on the Better control in Pediatric and Adolescent diabeteS: Working to crEate cEnTers of Reference (SWEET) database. There were 57 375 patients included in the study, aged ≤18 years from 54 SWEET centers. Only centers with screening for celiac disease were included. Regression models adjusted for age, diabetes duration, and gender and a fixed effect in the models for region was used. Diabetes duration, age at diabetes onset, and sex were presented as unadjusted results.

RESULTS

CD was present in 2652 subjects (4.5%), with different prevalence among regions: from 1.9% in Asia/Middle East to 6.9% in Australia/New Zealand. CD was observed more often among females. Comparing children with and without CD, characteristics for those with CD were younger age at diabetes onset (6.3 [3.3; 9.8] vs 8.1 [4.6; 11.3], P < 0.001) and had longer diabetes duration (6.4 [3.6; 9.8] vs 4.8 [2.1; 8.2], P < 0.001). Further, they had lower glycosylated hemoglobin (HbA1c) in Europe and North America/Canada; lower body mass index (BMI)-SD score (BMI-SDS) in southern Europe, North America, and Canada; In most regions daily insulin dose was lower, height-SDS was lower, and the percentage of insulin pump users was higher in children with T1D and CD.

CONCLUSIONS

The prevalence and the anthropometric and metabolic consequences of CD in children with T1D differ around the world.

[Changes of lactate levels in diabetic ketoacidosis and in newly diagnosed type 1 diabetes mellitus]

Introduction: It is known that lactate concentration is increased in diabetic ketoacidosis (DKA), however, the pathophysiology and kinetics of lactate changes are still unclear. Normally, L-lactate is the major form in the human body. According to previous data, also D- and L-lactate might be increased in hyperglycaemic disorders. Aim: We aimed to describe the kinetics and mechanisms of lactate concentration changes in ketoacidosis and newly diagnosed diabetes. Method: We performed a prospective study, including 5-18-year-old children with ketoacidosis (DKA, n = 13) and with newly diagnosed type 1 diabetes without ketoacidosis (T1DM, n = 6). We performed routine blood gas analysis 0-12-24-48 hours after admission, which also measured L-lactate levels. We also determined total venous serum lactate level by gas chromatography-mass spectrometry. Results: Initial plasma lactate concentration was increased in ketoacidosis as compared to the newly diagnosed diabetes group (p<0.05). After 12 h of rehydration, lactate levels were greatly reduced in ketoacidotic patients but after 24-48 h it was repeatedly increased (all p<0.01). In the 0-12 h phase, total serum lactate level was higher than L-lactate level, referring to D-lactate production. Conclusion: We described two L-lactate peaks in ketoacidosis. In the first 12 hours anaerobic glycolysis seems to have major role in hyperlactataemia. We assume that stimulated aerobic glycolysis leads to the second lactate peak. However, D-lactate is not routinely measured, it may contribute to the initial hyperlactataemia in both groups and is comparable to L-lactate production in ketoacidosis. Orv Hetil. 2019; 160(45): 1784-1790.

Modelling intestinal glucose absorption in premature infants using continuous glucose monitoring data

BACKGROUND

Model-based glycaemic control protocols have shown promise in neonatal intensive care units (NICUs) for reducing both hyperglycaemia and insulin-therapy driven hypoglycaemia. However, current models for the appearance of glucose from enteral feeding are based on values from adult intensive care cohorts. This study aims to determine enteral glucose appearance model parameters more reflective of premature infant physiology.

METHODS

Peaks in CGM data associated with enteral milk feeds in preterm and term infants are used to fit a two compartment gut model. The first compartment describes glucose in the stomach, and the half life of gastric emptying is estimated as 20 min from literature. The second compartment describes glucose in the small intestine, and absorption of glucose into the blood is fit to CGM data. Two infant cohorts from two NICUs are used, and results are compared to appearances derived from data in highly controlled studies in literature.

RESULTS

The average half life across all infants for glucose absorption from the gut to the blood was 50 min. This result was slightly slower than, but of similar magnitude to, results derived from literature. No trends were found with gestational or postnatal age. Breast milk fed infants were found to have a higher absorption constant than formula fed infants, a result which may reflect known differences in gastric emptying for different feed types.

CONCLUSIONS

This paper presents a methodology for estimation of glucose appearance due to enteral feeding, and model parameters suitable for a NICU model-based glycaemic control context.

[Clinical application of the electric cardiometry based non-invasive ICON® hemodynamic monitor]

Establishment of a proper hemodynamic monitoring system in order to achieve optimal care among critically ill patients is fundamental. In contrast to invasive patient-checking systems, which were introduced decades ago and used in both adult and pediatric intensive care, the non-invasive methods have become more popular in recent years due to technical advancements in intensive care and patient monitoring. This increase in popularity can be attributed to the higher degree of safety and reduced complication rates as well as to its being more economical. Our summary focuses on the ICON^® patient monitoring system. This newly engineered, non-invasive tool is based on electrical cardiometry, and uses hemodynamic parameters in both neonatal and pediatric care as well as in adults. The operating principle is simple: the conductivity of the blood in the aorta shows time-dependent changes. Prior to the opening of the aortic valve, the orientation of the red blood cells (RBCs) is random, and it is not until the contraction of the aorta that the RBCs and the opening of the aortic valve achieve a parallel position. The tool senses the conductivity between four placed electrodes, and measures the stroke volume (SV) and cardiac output (CO), before calculating other additional parameters (eg.: systemic vascular resistance) by tracing the variation of bioimpedance according to changes in the heart cycle. The most important advantages of ICON^® are the measurements that are made available immediately as well as continuously, and the low complication rate that originates from its non-invasive operation. ICON^® is a new, promising hemodynamic device in the tool belt of intensive care. Due to the nature of the device, it is possible to evaluate the status of the patient on a continuous basis, allowing for optimal care. To identify the more accurate clinical indications further measures will be necessary. Orv Hetil. 2018; 159(44): 1775-1781.

Association between interferon-induced helicase (IFIH1) rs1990760 polymorphism and seasonal variation in the onset of type 1 diabetes mellitus

BACKGROUND

Infections, mostly of viral origin, may contribute to the seasonal variation in the onset of type 1 diabetes mellitus (T1DM). The rs1990760 (A>G, Ala946Thr) polymorphism (GG genotype) of the interferon induced helicase (IFIH1), a virus recognition receptor, confers a modest protection for T1DM. The aim of our study was to evaluate a possible association between this IFIH1 polymorphism and the seasonal variation in the onset of T1DM.

MATERIALS AND METHODS

The IFIH1 rs1990760 polymorphism was genotyped in 1055 patients of Central-Eastern European ancestry with T1DM (median age at diagnosis: 8.2 [interquartile range, IQR 4.8-11.8] years). T1DM onset was recorded in monthly intervals.

RESULTS

The IFIH1 genotype distribution was the following: 436 patients (41.3%) had AA genotype, 483 patients (45.8%) had AG genotype, and 136 patients (12.9%) had GG genotype. Significant seasonal variation in manifestation of T1DM (highest rate in winter and lowest rate in summer period) was observed in the total cohort (n = 1055), irrespective of gender. The disease predisposing AA genotype was more frequently found among new cases with onset in summer vs in those with onset in winter (44.3% vs 37.9%); conversely, the protective GG genotype was less frequent (9.3% vs 12.9%, respectively; P = .0268 for trend). Significant effect of genotype (P = .0418) was found on the seasonal variability of T1DM onset in the total cohort.

CONCLUSIONS

The IFIH1 rs1990760 polymorphism seems to be associated with the seasonal manifestation of T1DM. Our findings suggest that this virus receptor gene may contribute to T1DM manifestation primarily in the summer period.

Evaluation of an open access software for calculating glucose variability parameters of a continuous glucose monitoring system applied at pediatric intensive care unit

Background

Continuous Glucose Monitoring (CGM) has become an increasingly investigated tool, especially with regards to monitoring of diabetic and critical care patients. The continuous glucose data allows the calculation of several glucose variability parameters, however, without specific application the interpretation of the results is time-consuming, utilizing extreme efforts. Our aim was to create an open access software [Glycemic Variability Analyzer Program (GVAP)], readily available to calculate the most common parameters of the glucose variability and to test its usability.

Methods

The GVAP was developed in MATLAB® 2010b environment. The calculated parameters were the following: average area above/below the target range (Avg. AUC-H/L); Percentage Spent Above/Below the Target Range (PATR/PBTR); Continuous Overall Net Glycemic Action (CONGA); Mean of Daily Differences (MODD); Mean Amplitude of Glycemic Excursions (MAGE). For verification purposes we selected 14 CGM curves of pediatric critical care patients. Medtronic® Guardian® Real-Time with Enlite® sensor was used. The reference values were obtained from Medtronic®^’s own software for Avg. AUC-H/L and PATR/PBTR, from GlyCulator for MODD and CONGA, and using manual calculation for MAGE.

Results

The Pearson and Spearman correlation coefficients were above 0.99 for all parameters. The initial execution took 30 minutes, for further analysis with the Windows® Standalone Application approximately 1 minute was needed.

Conclusions

The GVAP is a reliable open access program for analyzing different glycemic variability parameters, hence it could be a useful tool for the study of glycemic control among critically ill patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s12938-015-0035-3) contains supplementary material, which is available to authorized users.

Effects of pH, lactate, hematocrit and potassium level on the accuracy of continuous glucose monitoring (CGM) in pediatric intensive care unit

Background

Continuous glucose monitoring (CGM) originally was developed for diabetic patients and it may be a useful tool for monitoring glucose changes in pediatric intensive care unit (PICU). Its use is, however, limited by the lack of sufficient data on its reliability at insufficient peripheral perfusion. We aimed to correlate the accuracy of CGM with laboratory markers relevant to disturbed tissue perfusion.

Patients and Methods

In 38 pediatric patients (age range, 0–18 years) requiring intensive care we tested the effect of pH, lactate, hematocrit and serum potassium on the difference between CGM and meter glucose measurements. Guardian® (Medtronic®) CGM results were compared to GEM 3000 (Instrumentation laboratory®) and point-of-care measurements. The clinical accuracy of CGM was evaluated by Clarke Error Grid -, Bland-Altman analysis and Pearson’s correlation. We used Friedman test for statistical analysis (statistical significance was established as a p < 0.05).

Results

CGM values exhibited a considerable variability without any correlation with the examined laboratory parameters. Clarke, Bland-Altman analysis and Pearson’s correlation coefficient demonstrated a good clinical accuracy of CGM (zone A and B = 96%; the mean difference between reference and CGM glucose was 1,3 mg/dL, 48 from the 780 calibration pairs overrunning the 2 standard deviation; Pearson’s correlation coefficient: 0.83).

Conclusions

The accuracy of CGM measurements is independent of laboratory parameters relevant to tissue hypoperfusion. CGM may prove a reliable tool for continuous monitoring of glucose changes in PICUs, not much influenced by tissue perfusion, but still not appropriate for being the base for clinical decisions.

[Role of continuous subcutaneous glucose monitoring in intensive care]

Critical care associated with stress hyperglycaemia has gained a new view in the last decade since the demonstration of the beneficial effects of strong glycaemic control on the mortality in intensive care units. Strong glycaemic control may, however, induce hypoglycaemia, resulting in increased mortality, too. Pediatric population has an increased risk of hypoglycaemia because of the developing central nervous system. In this view there is a strong need for close monitoring of glucose levels in intensive care units. The subcutaneous continuous glucose monitoring developed for diabetes care is an alternative for this purpose instead of regular blood glucose measurements. It is important to know the limitations of subcutaneous continuous glucose monitoring in intensive care. Decreased tissue perfusion may disturb the results of subcutaneous continuous glucose monitoring, because the measurement occurs in interstitial fluid. The routine use of subcutaneous continuous glucose monitoring in intensive care units is not recommended yet until sufficient data on the reliability of the system are available. The Medtronic subcutaneous continuous glucose monitoring system is evaluated in the review partly based on the authors own results.

Occurence of thyroid autoimmunity in children with type 1 diabetes mellitus

Ismert, hogy azok a betegek, akikben egy autoimmun betegség már kialakult, fokozottan veszélyeztetettek más autoimmun betegségek fellépésével szemben. Korábban a szerzők kimutatták, hogy 1-es típusú diabéteszben szenvedő betegekben a coeliakia előfordulása gyakoribb, mint a háttérpopulációban. Az autoimmun pajzsmirigybetegség az 1-es típusú diabétesz leggyakoribb társbetegsége, amely általában az élet második évtizedében, az 1-es típusú diabétesz manifesztációját követően lép fel. Célkitűzés: Mindezek alapján a szerzők megvizsgálták a thyreoidea-autoimmunitás, illetve az autoimmun pajzsmirigybetegségek előfordulási gyakoriságát 1-es típusú diabéteszben szenvedő betegekben. Választ kerestek arra a kérdésre is, hogy változik-e a thyreoidea-autoimmunitás prevalenciája azokban a gyermekekben, akik a diabétesz mellett coeliakiában is szenvednek. Módszerek: 268 1-es típusú diabéteszben, valamint 48 1-es típusú diabéteszben és coeliakában szenvedő betegben az autoimmun pajzsmirigybetegségek irányába szűrővizsgálatot végeztek a thyreoglobulin- és a peroxidáz-ellenes antitestek vizsgálatával. Pozitivitás esetén a betegséget a pajzsmirigyfunkció vizsgálatával, illetve ultrahang elvégzésével igazolták. Eredmények: Vizsgálataik szerint a pajzsmirigyellenes antitestek előfordulási gyakorisága szignifikánsan magasabb volt azokban az 1-es típusú diabéteszes betegekben, akik egyidejűleg coeliakában is szenvedtek (1-es típusú diabétesz: 43 (16%), 1-es típusú diabétesz + coeliakia: 16 (33,3%, p < 0,01). A thyreoiditis talaján kialakult hypothyreosis is gyakrabban fordult elő azokban a diabéteszes betegekben, akik coeliakiásak voltak. Következtetések: A szerzők hangsúlyozzák, hogy a coeliakiában szenvedő 1-es típusú diabéteszes betegekben az autoimmun pajzsmirigybetegség fellépésének nagyobb valószínűsége miatt ennek a populációnak az autoimmun pajzsmirigybetegségek iránti rendszeres szűrése feltétlenül indokolt.

Genetic polymorphisms and risk for acute renal failure in preterm neonates

Acute renal failure (ARF) affects about 10% of severely ill neonates. Recent studies have shown that genetic polymorphisms of proteins that play a role in neonatal physiology may contribute to individual susceptibility to both ARF and its risk factors. Our review summarizes the data collected to date. Studies have shown that the risk of preterm neonates for ARF is directly associated with a combination of high tumor necrosis factor-alpha producer and low interleukin-6 producer genotypes, as well as with low heat shock protein 72 producer genotype. Premature birth is itself the most important risk factor for a number of complications, including ARF, and recent studies have also shown an association between several maternal and fetal cytokine genetic polymorphisms and increased inflammatory response in preterm neonates. These polymorphisms could also be associated with increased risk for disorders such as sepsis and necrotizing enterocolitis, which lead to renal hypoperfusion and ARF. Genetic polymorphisms of the renin-angiotensin-aldosterone system have not been shown to directly influence risk for ARF. They may, however, be associated with patent ductus arteriosus, poor postnatal adaptation, and heart failure, which are all prevalent risk factors for ARF.

[Continuous glucose monitoring system, as a valuable tool in the care of children and adolescents with diabetes mellitus]

INTRODUCTION

Good metabolic control of diabetic patients is mainly based on the results of self measured blood glucose levels. Important excursions of blood glucose may, however, be hidden in the usual case of 4-5 daily determinations. The aim of this paper was to give detailed information about this new diagnostic tool and to report the first Hungarian pediatric experiences with continuous glucose monitoring.

METHOD

Continuous glucose monitoring system (Mini-Med) is able to monitor the changes of tissue glucose levels for up to 72 hours by measuring glucose concentration via a s.c. canula every 5 minutes. In its present form the results of continuous glucose monitoring cannot be observed real time by the patient, it provides useful information retrospectively mainly for the doctor.

RESULTS

The sensor detected unexpectedly high fluctuation of glucose levels in several patients. It was possible to distinguish between nighttime hypoglycaemia (Somogyi-effect) or dawn phenomenon-induced morning hyperglycaemiae by the use of continuous glucose monitoring. Fever may influence peripheral circulation representing a limitation in the use (or evaluation) of continuous tissue glucose monitoring. The authors found good correlation between continuous glucose monitoring and self blood glucose monitoring results. The best correlation was observed in the low blood glucose range.

CONCLUSIONS

The continuous glucose monitoring results provide useful information for the diabetologist in order to modify insulin treatment. Continuous glucose monitoring-based changes in insulin treatment are reported to result in better long term metabolic control. Continuous glucose monitoring in the near future will obviously play a primary role in insulin pump therapy where it will provide glucose result for the pump.

Association between heat shock protein 72 gene polymorphism and acute renal failure in premature neonates

Heat shock protein (HSP)70 plays an important role in the ischemic tolerance of fetal and neonatal kidney. We have investigated the association of genetic polymorphisms of the constitutive HSP70 (HSP73) and the inducible HSP70 (HSP72) encoding genes with the risk of acute renal failure (ARF) in very low birth weight (VLBW) neonates. Thirty-seven VLBW neonates with ARF and 93 VLBW neonates without ARF were enrolled in the study. The presence of HSP72 (1267)AG and HSP73 (190)GC polymorphism was analyzed from dried blood samples by PCR and restriction length fragment polymorphism. Allelic prevalence was related to reference values obtained in 131 healthy adults. Stepwise binary logistic regression was applied to determine the independent effect of the established risk factors to the development of ARF. Sixteen of 37 VLBW neonates with ARF and 18 of 93 VLBW neonates without ARF were homozygous for HSP72 (1267)G allele (p </= 0.01). The association between HSP72 (1267)GG genotype and ARF remained at the level of significance (p = 0.05) when it was adjusted for established risk factors of neonatal ARF. Prevalence of HSP72 (1267)GG was also higher in VLBW neonates than in the reference population (p < 0.05) and in VLBW neonates with infant respiratory distress syndrome than in those without (p < 0.001). We found that in VLBW neonates carrying HSP72 (1267)GG genetic variation, which is associated with low inducibility of HSP72, the risk of ARF was increased. Therefore, VLBW neonates with (1267)GG might express less HSP72 and might be less protected against ARF.

Association between G-308A polymorphism of the tumor necrosis factor-alpha gene and 24-hour ambulatory blood pressure values in type 1 diabetic adolescents

Tumor necrosis factor-alpha (TNF-alpha) is an inflammatory cytokine, which also influences blood pressure (BP). The G-308A polymorphism of the TNF-alpha gene is associated with altered TNF-alpha production. The prevalence of the TNF-alpha-308A allele is reportedly higher among patients with type 1 diabetes mellitus (T1DM) than in the healthy population. In this study we investigated whether this genetic polymorphism might correlate with BP values in diabetic adolescents. Ambulatory BP monitoring (ABPM) was performed in 126 adolescents with T1DM (mean age: 14 +/- 2.4 years). The TNF-alpha G-308A genotype was determined by using polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) methodologies. ABPM results were related to healthy reference values and are given as standard deviation score (SDS). The prevalence of the -308A allele was higher in diabetic adolescents than the Hungarian reference population (0.26 vs 0.14, p < 0.01). TNF-alpha genotype was associated both with systolic and diastolic BP values (p < 0.01 and p < 0.01, respectively). In patients with TNF-alpha-308GG and -308GA/AA genotypes, the 24-h systolic BP average values were 0.37 +/- 1.33 and -0.38 +/- 1.28 SDS, while 24-h diastolic BP average values were 0.09 +/- 1.30 and -0.67 +/- 1.31 SDS. Hence, the TNF-alpha-308A allele carrier state appears to be associated with lower systolic and diastolic BP values.

Interleukin genetic variants and the risk of renal failure in infants with infection

Systemic infection is a major risk factor for the development of neonatal acute renal failure (ARF). We investigated whether genetic polymorphisms of tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, IL-6, and IL-10 genes leading to a more intense inflammatory response might predispose very low birth weight (VLBW) infants to the development of ARF in severe infection. The medical records of 92 VLBW newborns (birth weight under 1,500 g) with systemic infection were analyzed. ARF developed in 38 infants during the 1st postnatal week, while 54 neonates exhibited normal renal function. The variants of TNF-alpha, IL-1beta, IL-6, and IL-10 genes were determined from dried blood samples with polymerase chain reaction and restriction fragment length polymorphism methods. The allele frequencies did not differ in ARF and in non-ARF babies, while the (TNF-alpha /IL-6) AG/GC or AG/CC haplotypes were more often present in ARF (26% vs. 6%, P<0.01). The single presence of TNF-alpha, IL-1beta, IL-6, and IL-10 variants does not influence the development of ARF, but the constellation of TNF-alpha and IL-6 genetic variants is associated with ARF. We hypothesize that the simultaneous presence of these polymorphisms might lead to an enhanced inflammatory response in the kidneys in babies with infection.

Variance of ACE and AT1 receptor gene does not influence the risk of neonatal acute renal failure

High neonatal activity of the renin-angiotensin system (RAS) is crucial for the maintenance of glomerular filtration of the newborn. The aim of the present study was to investigate whether genetic polymorphisms leading to lower angiotensin converting enzyme activity (ACE) or impaired functionality of angiotensin II (AII) type 1 receptor (AT1R) might predispose very low birth weight newborns (VLBWs) to the development of acute renal failure (ARF). The medical records of 110 VLBW infants were analyzed. ARF developed in 42 of them during the first postnatal week, while 68 neonates exhibited normal renal function. The ACE I/D polymorphism and the A1166C variants of AT1R were determined from dried blood samples. The frequency of the ACE I allele did not differ in ARF and non-ARF groups (0.307 and 0.284); the frequency of the AT1R C1166 variant was also the same in ARF and non-ARF groups (0.250 and 0.227). Although low activity of RAS has been implicated in the development of neonatal ARF and data indicated that the functionality of RAS is influenced by the I/D variants of the ACE gene and the A1166C variant of the AT1R gene, we could not demonstrate any effect of these polymorphisms on the development of ARF in VLBW infants.

Signs of autonomic neuropathy in childhood uremia

To evaluate the presence of autonomic neuropathy in childhood uremia, cardiovascular autonomic reflexes were examined in children with chronic renal failure. Cardiovascular autonomic reflexes of 10 uremic patients on chronic dialysis and 10 transplanted patients were compared to assess the effect of transplantation on autonomic neuropathy. Resting heart rate, heart rate changes induced by deep breathing, by Valsalva maneuver, and following standing up, and blood pressure change induced by handgrip test were examined. Of the 10 uremic children, 4 showed early involvement and 2 had definite involvement of autonomic neuropathy. Only 1 of the 10 transplanted patients showed early signs of autonomic neuropathy. Autonomic tests demonstrated predominantly parasympathetic dysfunction. In conclusion, cardiovascular autonomic neuropathy is not rare in children and adolescents and young adults with chronic renal failure. In contrast, the prevalence is very low in transplanted patients with similar uremic precedents. Efforts should be made to prevent or delay this uremia-related complication.

Monitoring cardiovascular changes during hemodialysis in children

Hemodialysis (HD) causes rapid volume shifts and circulatory changes. In chronic renal failure (CRF) Na+/K+ATP-ase is depressed, whereas endogenous digoxin-like factor (EDLF) is elevated. Our aim was to characterize HD-induced cardiovascular adaptation and its possible links to Na+/K+ATP-ase and EDLF. Eleven children with CRF on HD (aged 14.7 +/- 3.7 years) and 11 healthy children were investigated for basic circulatory parameters. Thoracic impedance (Zo) and circulatory parameters were monitored by impedance cardiography (ICG) during HD. Erythrocyte Na+/K+ATP-ase and EDLF were measured before and after HD. Up to the loss of 6% of total body weight, Zo rose linearly with fluid removal, above this no further increase occurred. Heart rate and mean arterial pressure (MAP) were inversely related (r = -0.97); MAP rose in the first and decreased in the second part of HD. Systemic vascular resistance paralleled MAP, whereas stroke volume rapidly decreased, but stabilized in the second part of HD. The ratio of preejection period/ventricular ejection time (PEP/VET) correlated positively with HD duration (r = 0.92), suggesting diminished cardiac filling. Cardiac index (CI) remained stable. EDLF was high in uremia accompanied by depressed Na+/K+ATP-ase (P < 0.05 and P < 0.01, respectively). Following HD Na+/K+ATP-ase normalized. Correlation between Na+/K+ATP-ase activity and MAP was linear (r = 0.85). In conclusion, ICG during HD provides detailed information concerning circulatory adaptation resulting in stable CI, suggesting that the dialysis-induced hypovolemia is compensated by the centralization of the blood volume. Changes of Na+/K+ATP-ase indicate that dialyzable blood pressure-regulating substance(s) inhibit(s) the pump. However, lack of further correlation between Na+/K+ATP-ase, EDLF, and cardiovascular parameters indicates the complexity of the regulatory processes.

Endogenous bradykinin regulates renal function in the newborn rabbit

The developmental changes in the activity of the renal kallikrein-kinin system (KKS) are related to the hemodynamic changes occurring in the neonatal kidney. In order to clarify the functional importance of the renal KKS in the developing kidney, the effect of the bradykinin B2 receptor antagonist HOE-140 was investigated in newborn rabbits. Effective blockade of bradykinin effect by HOE-140 was demonstrated in 10 rabbits. In 10 additional animals the subcutaneous injection of 300 micrograms/kg HOE-140 resulted in an increase in renal vascular resistance with a consequent decrease in renal blood flow. Glomerular filtration rate did not change significantly, while the filtration fraction rose, indicating preferential efferent arteriolar constriction. Urine flow rate increased as well as the fractional excretion of potassium. No change in sodium excretion was observed. The present data suggest a regulatory role for the renal KKS in the immature kidney under basal conditions. By inducing predominant efferent arteriolar vasodilation, the KKS appears to play a key role in regulating the neonatal glomerular microcirculation. This is in sharp contrast with the mature kidney, where the KKS predominantly acts on tubular function as a diuretic-natriuretic factor.

Chronic bradykinin receptor blockade modulates neonatal renal function

Recent data indicate that bradykinin participates in the regulation of neonatal glomerular function and also acts as a growth regulator during renal development. The aim of the present study was to investigate the involvement of bradykinin in the maturation of renal function. Bradykinin beta2-receptors of newborn rabbits were inhibited for 4 days by Hoe 140. The animals were treated with 300 microg/kg s.c. Hoe 140 (group Hoe, n = 8) or 0.9% NaCl (group control, n = 8) twice daily. Clearance studies were performed in anesthetized rabbits at the age of 8-9 days. Bradykinin receptor blockade did not impair kidney growth, as demonstrated by similar kidney weights in the two groups, nor did it influence blood pressure. Renal blood flow was higher, while renal vascular resistance and filtration fraction were lower in Hoe 140-treated rabbits. No difference in glomerular filtration rate was observed. The unexpectedly higher renal perfusion observed in group Hoe cannot be explained by the blockade of the known vasodilator and trophic effect of bradykinin. Our results indicate that in intact kallikrein-kinin system is necessary for the normal functional development of the kidney.

The stressed neonatal kidney: from pathophysiology to clinical management of neonatal vasomotor nephropathy

The healthy term, and particularly the premature infant, is born with a very low glomerular filtration rate (GFR), controlled by a delicate balance of intrarenal vasoconstrictor and vasodilator forces. Vasoactive disturbances can easily further reduce the already low GFR. The newborn infant is thus prone to develop vasomotor nephropathy (VMNP) or acute renal failure (ARF). The main causes for ARF at this young age are prerenal mechanisms, and include hypotension, hypovolemia, hypoxemia perinatal asphyxia, and neonatal septicemia. Other causes include the administration of angiotensin converting enzyme inhibitors, indomethacin and tolazoline. The most-important factors governing the ultimate renal prognosis are the severity of the underlying disorder, the rapidity of an accurate diagnosis, prompt treatment, and avoidance of severe iatrogenic complications. The immediate treatment is of particular importance in VMNP, i.e., prerenal ischemic ARF, and consists of correcting abnormalities in fluid homeostasis and reduction of the complications of the acute azotemic state (uremia, hyperkalemia, acidosis, and hypertension). In severe and prolonged (established) ARF, temporary dialysis therapy may be indicated. Prerenal ARF with oliguria or anuria warrants immediate volume resuscitation. Special attention should be given to infants with congestive heart failure (CHF). The sick neonate with persistent oliguria and CHF should be treated with intravenous dopamine. Furosemide (FM) is the second line of therapy for babies with indomethacin-induced ARF. In most other conditions, the therapeutic effect of FM is limited to a transient increase in urine flow, without improving basic renal function. The special conditions of the maturing kidney have to be appreciated in order to protect babies from undue renal injury. With the increasing knowledge of the mechanisms governing the development of ARF, progress has been made in the development of new treatment modalities. For example theophylline, calcium antagonists, ATP-MgCl2, thyroxine, and a variety of cytokines may in the near future be used to prevent or ameliorate VMNP and/or recently established ARF. With a combination of time-honored and new therapeutic strategies, there may well be a brighter future for neonates with vasomotor, prerenal, ischemic ARF.

The role of bradykinin in neonatal hemodynamic effects of ACE inhibition

Angiotensin-converting enzyme (ACE) inhibitors exert their effects by inhibiting angiotensin II (AII) production, but also by inhibiting bradykinin (BK) degradation. In order to clarify whether BK is involved in the systemic effects of ACE inhibition in the newborn period, we investigated the effect of perindoprilat (20 microgram/kg i.v.) in newborn rabbits, with or without the blockade of BK beta(2)-receptors (Hoe 140, 300 microgram/kg s.c.). The bolus infusion of perindoprilat resulted in a marked fall in mean arterial blood pressure (MBP) and a slight decrease in heart rate. BK receptor blockade had no effect on the perindoprilat-induced hypotension but the negative chronotropic effect of ACE inhibition was partly prevented by pretreatment with Hoe 140. We therefore conclude that BK is not involved in neonatal blood pressure regulation but that the ACE inhibition-induced neonatal bradycardia is at least partly BK- mediated.

Bradykinin and hypoxemia-induced renal changes in the newborn rabbit

Acute hypoxemia causes a decrease in glomerular filtration rate (GFR) and renal blood flow (RBF) in newborns. These changes are partly mediated by local-acting vasoactive factors. We have previously shown that bradykinin (BK) has a vasodilatory role in the basic regulation of neonatal hemodynamics. The purpose of the present study was to evaluate whether BK can modulate the severe renal vasoconstriction associated with hypoxemia in the newborn rabbit. The effect of systemic hypoxemia (PaO2 approximately 40 mmHg) on renal function was investigated in 9 newborn rabbits (controls) and in 8 animals in which BK-B2 receptors were blocked by Hoe 140 (300 microg/kg subcutaneously), given prior to the induction of hypoxemia. The studies were performed under pentobarbital anesthesia at the age of 5-9 days. In control animals, acute hypoxemia caused a significant decrease in GFR and RBF and an increase in renal vascular resistance. Similar glomerular hemodynamic changes were observed in BK-B2 receptor-blocked newborn rabbits. These results indicate that BK does not play a significant role in the renal vascular changes of the hypoxemic-stressed newborn.

Role of bradykinin in the neonatal renal effects of angiotensin converting enzyme inhibition

The vascular effects of angiotensin converting enzyme inhibitors are mediated by the inhibition of the dual action of angiotensin converting enzyme (ACE): production of angiotensin II and degradation of bradykinin. The deleterious effect of converting enzyme inhibitors (CEI) on neonatal renal function have been ascribed to the elevated activity of the renin-angiotensin system. In order to clarify the role of bradykinin in the CEI-induced renal dysfunction of the newborn, the effect of perindoprilat was investigated in anesthetized newborn rabbits with intact or inhibited bradykinin B2 receptors. Inulin and PAH clearances were used as indices of GFR and renal plasma flow, respectively. Perindoprilat (20 microg/kg i.v.) caused marked systemic and renal vasodilation, reflected by a fall in blood pressure and renal vascular resistance. GFR decreased, while urine flow rate did not change. Prior inhibition of the B2 receptors by Hoe 140 (300 microg/kg s.c.) did not prevent any of the hemodynamic changes caused by perindoprilat, indicating that bradykinin accumulation does not contribute to the CEI-induced neonatal renal effects. A control group receiving only Hoe 140 revealed that BK maintains postglomerular vasodilation via B2 receptors in basal conditions. Thus, the absence of functional B2 receptors in the newborn was not responsible for the failure of Hoe 140 to prevent the perindoprilat-induced changes. Species- and/or age-related differences in the kinin-metabolism could explain these results, suggesting that in the newborn rabbit other kininases than ACE are mainly responsible for the degradation of bradykinin.

Direct renovascular effect of somatostatin in the dog

Recently, effects of somatostatin on the renal function have been described and the vasoactive properties of the peptide were proposed to contribute to this action. However, the available data on its effect in the renal vascular bed are very controversial. Therefore, we investigated the effect of local intaarterial somatostatin boluses in a wide range of doses (5 x 10(-11) - 5 x 10(-5) g) on the renal blood flow (RBF) in anesthetized dogs. RBF was measured by an electromagnetic flow probe. Somatostatin did not influence blood pressure or heart rate. RBF exhibited a significant, dose-dependent fall (ranging from 11.6 +/- 11.9% to 31.9 +/- 17.3%), with a threshold at a dose of 5 x 10(-10) g. These results offer conclusive evidence for the contribution of somatostatin-induced direct renal vasoconstriction to its renal effects, in addition to the demonstrated modulation of other vasoactive systems and tubular functions.