Study of bone metabolism in children and adolescents with type I diabetes mellitus: the role of sclerostin

Introduction: Diabetes Mellitus (DM) is a risk factor for reduced bone mass. Several bone metabolic pathways seem to be disrupted in patients with type 1 diabetes mellitus (T1DM), leading to the observed reduced Bone Mineral Density (BMD). Sclerostin and dickkopf-1 are inhibitors of the Wnt/b-catenin bone metabolic pathway. Increased sclerostin and dickkopf-1 levels and have been documented in adult patients with Diabetes Mellitus (DM), predominantly in those with T2DM. No relevant data exist on childhood T1DM. Furthermore, Osteoprotegerin (OPG) has been found higher in young T1DM patients, while Receptor Activator of Nuclear factor-KappaB Ligand(s-RANKL) has been found with comparable levels to controls.Aims Our aim was to study plasma sclerostin, dickkopf-1, OPG and s-RANKL concentration in children and adolescents with T1DM and controls and to correlate their levels with metabolic bone markers and BMD.Materials and Methods: We evaluated 40 children and adolescents with T1DM (mean±SD age 13.04±3.53 years, mean±SD T1DM duration 5.15±3.33years) and 40 healthy age- and gender-matched controls (mean±SD age 12.99±3.3years). Sclerostin, dickkopf-1, OPG, s-RANKL, Osteocalcin, C-telopeptide crosslinks-CTX, electrolytes, PTH, total alkaline phosphatise (ALP) and 25(OH)D were measured. Lumbar spine and total body Bone Mineral Density(BMD) were evaluated with dual energy X-ray absorptiometry (DXA). Results: Patients had significantly lower BMD than controls (L1-L4 BMD Z-score -0.17SD vs 0.23SD, p=0.03, total body BMD Z-score 0.23SD vs 0.56SD, p=0.04). Patients had significantly higher levels of OPG (6.15±1.56 vs 5.01±1.5 pmol/L, p<0.001), s-RANKL(logS-RANKL 5.97±0.63 vs 5.51±0.84, p=0.004) and ALP and lower levels of PTH and magnesium. Patients and controls had comparable 25(OH)vitD levels, while one third of both groups had low 25(OH)vitD levels(<20ng/ml). Osteocalcin was highly correlated with CTX in both groups (r=0.75, p<0.001), indicating coupling of bone resorption and formation but lower levels of both markers in patients could indicate lower bone turnover and osteoblastic disorder. OPG and s-RANKL were associated in controls (R2=0.15, p=0.021) but not in patients (R2=0.006, p=0.64), possibly indicating an osteoclastic disorder . Sclerostin levels in patients and controls were comparable (51.56±12.05 vs 50.98±13.55 pmol/L, p=0.84). Lower values were found in girls (49.1±12.7 vs 53.9±12.3 pmol/L, p=0.05) and in prepubertal children (47.3±11.6 vs 53.3±12.9 pmol/L, p=0.02). Sclerostin values significantly and gradually increased in children through pubertal Tanner stages 1 to 3, then reduced in stage 4 adolescents and increased again in pubertal stage 5 adolescents (ANOVA F=4.56, p=0.0024). Sclerostin levels were positively correlated with logCTX, logOsteocalcin and BMD Z-scores. Dickkopf-1 levels were found higher in patients(13.56±5.34 vs 11.35±3.76 pmol/L, p=0.0194), in boys (13.36±4.04 vs 11.72±5.14 pmol/L, p=0.02) and prebubertal children (13.61±4.87 vs 11.83±4.56 pmol/L, p=0.05). Dickkopf-1 was positively associated with logCTX, logOsteocalcin and IGF-1 in both groups, while in patients it was associated with OPG and fasting plasma glucose. The lowest dickkopf-1 values were found in Tanner stage 3 adolescents. Conclusions: RANKL/OPG axis seems to be significantly activated in patients with T1DM. These changes could indicate abnormal osteoclast function, while lower bone turnover could indicate abnormal osteoblast function and both could be associated with the lower bone mass, found in T1DM patients. Children and adolescents with T1DM had similar sclerostin but higher levels of dickkopf-1 than controls, indicating a downregulated Wnt/b-catenin bone metabolic pathway. Dickkopf-1 association with OPG and plasma fasting glucose in patients could indicate dickkopf-1 implication in RANKL/OPG axis dysregulation in that group. The decrease in sclerostin values observed in pubertal stage 4 adolescents and dickkopf-1 values in pubertal stage 3 adolescents coincide with the concurrent growth spurt, and are consistent with sclerostin and dickkopf-1 physiology as inhibiting signals. The only current realistic measures against bone disease in patients with T1DM are optimal glycaemic control along with regular physical exercise.Εισαγωγή: Αρκετές οστικές μεταβολικές οδοί διαταράσσονται στους ασθενείς με Σακχαρώδη Διαβήτη τύπου 1(T1ΣΔ) με αποτέλεσμα να ανευρίσκεται μειωμένη οστική πυκνότητα(BMD). Η σκληροστίνη και ο dickkopf-1 είναι αναστολείς της μεταβολικής οδού Wnt/β-κατενίνης των οστών. Αυξημένα επίπεδα σκληροστίνης και dickkopf-1 έχουν τεκμηριωθεί σε ενήλικες Τ2ΣΔ ασθενείς, ενώ δεν υπάρχουν μελέτες στα παιδιά με Τ1ΣΔ. Ομοίως η Οστεοπροτεγερίνη(OPG) έχει βρεθεί αυξημένη στους νεαρούς ασθενείς με Τ1ΣΔ, ενώ ο παράγοντας Receptor Activator of Nuclear factor-KappaB Ligand (s-RANKL) δεν έχει βρεθεί να διαφοροποιείται σημαντικά.Σκοπός: Η μελέτη της σκληροστίνης, του dickkopf-1, της OPG, του s-RANKL, καθώς και η μελέτη δεικτών οστικού μεταβολισμού σε παιδιά και εφήβους με Τ1ΣΔ και σε φυσιολογικά παιδιά και η συσχέτιση των τιμών των αναφερθέντων παραμέτρων τόσο μεταξύ τους όσο και με την ΟΠ.Υλικό: Αξιολογήθηκαν 40 παιδιά και έφηβοι με T1ΣΔ (μέση τιμή±SD ηλικίας:13.04± 3.53 έτη, διάρκεια ΣΔ1: 5.15±3.33 έτη), και 40 υγιείς μάρτυρες (μέση τιμή±SD ηλικίας 12.99±3.3 έτη). Μέθοδος: Μετρήθηκαν η σκληροστίνη, ο dickkopf-1, η οστεοκαλσίνη, τα καρβοξυτελικά πεπτίδια αποδόμησης του κολλαγόνου-CTX, η OPG, ο παράγοντας s-RANKL,ηλεκτρολύτες, παραθορμόνη(PTH), ολική αλκαλική φωσφατάση (ALP) και 25(OH)D. Η ολόσωμη BMD (ΤΒ-ΒΜD) και η BMD οσφυϊκής μοίρας σπονδυλικής στήλης (L1-L4 BMD) αξιολογήθηκαν με απορρόφησιομέτρηση ακτίνων Χ διπλής ενέργειας(DXA).Αποτελέσματα: Η BMD ήταν σημαντικά χαμηλότερη στους ασθενείς από τους μάρτυρες (L1-L4 BMD Z-score -0.17 SD vs 0.23 SD, p=0.03, TB-BMD Z-score 0.23 SD vs 0.56 SD, p=0.04). Οι ασθενείς είχαν υψηλότερα επίπεδα OPG (6.15±1.56 vs 5.01±1.5 pmol/L, p<0,001), s-RANKL(logs-RANKL 5.97±0.63vs5.51±0.84, p=0.004), dickkopf-1 (13.56±5.34 vs 11.35±3.76 pmol/L, p=0.0194) και ALP και χαμηλότερα επίπεδα οστεοκαλσίνης, CTX, ΡΤΗ και μαγνησίου από τους μάρτυρες. Οι ασθενείς και οι μάρτυρες είχαν συγκρίσιμα επίπεδα 25(ΟΗ)VitD, ενώ το ένα τρίτο αμφοτέρων των ομάδων είχε χαμηλά επίπεδα 25(ΟΗ)VitD (<20ng/ml). H oστεοκαλσίνη και η CTX συσχετίζονταν σε αμφότερες τις ομάδες (r=0.75, p<0.001), υποδεικνύοντας σύζευξη οστικής απορρόφησης και σχηματισμού. Η OPG και ο s-RANKL συσχετίζονταν σημαντικά στους μάρτυρες (R2=0.15, ρ=0.021), αλλά όχι στους ασθενείς (R2=0.006, p=0.64), υποδεικνύοντας πιθανώς οστεοκλαστική διαταραχή, ενώ οι χαμηλότερες τιμές οστεοκαλσίνης και CTX στους ασθενείς πιθανότατα υποδεικνύουν χαμηλότερο ρυθμό οστικής εναλλαγής και οστεοβλαστική δυσλειτουργία. Η σκληροστίνη δεν διέφερε σημαντικά μεταξύ ασθενών και μαρτύρων (51.56±12.05 vs 50.98±13.55 pmol/L,p=0.84). Χαμηλότερες τιμές βρέθηκαν στα κορίτσια (49.1±12.7 vs 53.9±12.3 pmol/L,p=0.05) και σε παιδιά προεφηβικής ηλικίας (47.3±11.6 vs 53.3±12.9 pmol/L, p=0.02). Στους ασθενείς και μάρτυρες οι τιμές σκληροστίνης σταδιακά αυξήθηκαν στα παιδιά σταδίου ενήβωσης Tanner 1-3, μειώθηκαν στο στάδιο 4 και αυξήθηκαν ξανά στους εφήβους σταδίου 5 (ANOVA F =4.56, p=0.0024). Η σκληροστίνη συσχετίστηκε θετικά με την logCTX, logOsteocalcin και τα Z-scores της ΒΜD. Ο dickkopf-1 βρέθηκε επίσης με υψηλότερα επίπεδα στα αγόρια (13.36±4.04 vs 11.72±5.14 pmol/L, p=0.02) και στα προεφηβικά παιδιά (13.61±4.87 vs 11.83±4.56 pmol/L, p=0.05), ενώ συσχετίστηκε θετικά με τη logCTX, τη logOsteocalcin, τον IGF-1 και στους ασθενείς επιπλέον με την OPG και τη γλυκόζη νηστείας. Οι χαμηλότερες τιμές dickkopf-1 βρέθηκαν στους εφήβους με στάδιο Tanner 3. Συμπεράσματα: Ο άξονας RANKL/OPG φαίνεται να ενεργοποιείται σημαντικά στα παιδιά και τους εφήβους με Τ1ΣΔ. Οι αλλαγές αυτές ενδεχόμενα υποδεικνύουν διαταραγμένη οστεοκλαστική λειτουργία, ενώ η χαμηλή οστική εναλλαγή υποδεικνύει διαταραγμένη οστεοβλαστική λειτουργία και θα μπορούσαν αμφότερες να συνδέονται με τη χαμηλότερη οστική μάζα, που διαπιστώθηκε στους ασθενείς. Οι ασθενείς και οι μάρτυρες είχαν παρόμοια επίπεδα σκληροστίνης αλλά σημαντικά αυξημένα επίπεδα dickkopf-1, υποδεικνύοντας καταστολή της μεταβολικής οδού Wnt/β-κατενίνης των οστών. Η συσχέτιση στους ασθενείς του dickkopf-1 με τη γλυκόζη νηστείας και την OPG είναι πιθανότατα ενδεικτική της συμμετοχής του dickkopf-1 στη διαταραχή του άξονα RANKL/OPG. Η μείωση των τιμών σκληροστίνης που παρατηρήθηκε στους εφήβους σταδίου ενήβωσης 4 και του dickkopf-1 στους εφήβους σταδίου ενήβωσης 3 συμπίπτουν με το ταυτόχρονο άλμα ανάπτυξης, και συνάδουν με τη φυσιολογία της σκληροστίνης και του dickkopf-1 ως ανασταλτικά σήματα της οστεοσύνθεσης. Ο καλός μεταβολικός έλεγχος και η φυσική δραστηριότητα είναι προς το παρόν τα μόνα ρεαλιστικά μέτρα για την καλή σκελετική υγεία των πασχόντων από Τ1ΣΔ

Bcl-2 and caspase-9 serum levels in children and adolescents with idiopathic epilepsy and active seizures.

BACKGROUND: In the present study we investigated the levels of proapoptotic caspase-9 and antiapoptotic Bcl-2 proteins in the sera of children and adolescents with idiopathic epilepsy and tried to relate the findings to the patients&apos; clinical parameters. METHODS: This retrospective study consisted of 118 children and adolescents with idiopathic epilepsy, categorized according to type and number of seizures, duration of the disease and the control of seizures and 30 age- and sex-matched controls. The relapse of seizures was taken into consideration. RESULTS: Mean serum level between Bcl-2 and caspase-9 was significantly higher only in Bcl-2 patients, compared to controls (P≤0.0001) and (P=0.987) respectively. Significant difference in Bcl-2 level was found among the different types of focal seizures. Caspase-9 level was statistically different in patients with two or more seizures per month compared to those with one seizure per month (P=0.048). No correlation was found between Bcl-2 and caspase-9 levels and age, gender, seizure frequency, total number of seizures and the duration of epilepsy. No significant difference was found in patients with and without drug treatment. CONCLUSIONS: Bcl-2 displays an association with apoptosis and highlights the potential of being a surrogate biomarker for active seizures and epilepsy. There is a significant difference in Bcl-2 serum level among the different types of focal seizures. Proapoptotic caspase-9 cannot act as a marker of active seizures and epilepsy. Caspase-9 serum level is increased acutely in controlled cases after a single relapse

The Effect of Metabolic Profile on Leptin, Adiponectin, and hs-CRP in Children and Adolescents with Type 1 Diabetes

Adipokines are a superfamily of cell signaling proteins produced by the adipose tissue. This study&rsquo;s purpose was to reveal the association of adipokines (leptin, adiponectin), hs-CRP, and IL-6 with well-known cardiovascular risk factors (lipid profile, diabetes control, obesity, physical activity) in children and adolescents with T1D. This cross-sectional study included 80 participants (36 boys) with T1D, aged (mean &plusmn; SD) 14.8 &plusmn; 3.4 years. Body Mass Index (BMI), metabolic profile, and level of physical activity were assessed (using pedometers) for evaluation of their effect on serum leptin, adiponectin, IL-6, and hs-CRP. Leptin levels were associated with BMI (beta = 0.184, p &lt; 0.001), waist to hip ratio (beta = &minus;2.017, p = 0.022), Low Density Lipoprotein-C (LDL-C) (beta = 0.021, p = 0.005), and fat mass (beta = 14.07, p &lt; 0.001). Adiponectin was correlated with waist to height ratio (beta = 0.048, p = 0.006), &Beta;&Mu;&Iota; (beta = &minus;0.056, p = 0.005), and muscle mass (beta = &minus;0.013, p = 0.020). Interestingly, hs-CRP was associated with weight (beta = 0.035, p &lt; 0.001), &Beta;&Mu;I (beta = 0.186, p &lt; 0.001), fat mass (beta = 5.2859, p = 0.004), and muscle mass (beta = 0.027, p = 0.008). Multiple regression analysis of muscle mass unveiled associations with log hs-CRP (beta = &minus;1.237, p = 0.014) and inverse IL&minus;6 (beta = 18.57, p = 0.01). Finally, multiple regression models of fat mass unveiled associations with physical activity (7-day-total-step-count) (beta = &minus;3.90 &times; 10&minus;7, p = 0.027), Inverse IL-6 (beta = &minus;0.1572, p = 0.009), and squared leptin (beta = 0.0077, p = 0.03). This study reports a positive association of leptin with LDL-C, BMI, fat mass, and hip circumference and a negative association of adiponectin with BMI and muscle mass. Finally, hs-CRP was associated with HbA1c, fat mass, and BMI. We propose that leptin, adiponectin, and hs-CRP could be used as prognostic indicators of cardiovascular risk in children with T1D

The Role of Exercise on Cardiometabolic Profile and Body Composition in Youth with Type 1 Diabetes

Exercise has a direct positive effect on glycemic control by promoting insulin secretion from β-pancreatic islet-cells and by increasing skeletal muscle glucose uptake. The reduction in daily insulin needs and the optimization of glycemic control improves the patient’s quality of life, self-esteem, mental wellness, as well as diabetes-related mobility and mortality. The aim of this study was to investigate the effect of physical activity in children and adolescents with type-1 diabetes (T1D) on diabetic control, cardiovascular, and biochemical profiles; hs-CRP; IL6; leptin; and adiponectin levels of the population under study. This is a prospective cross-sectional study that involved 80 participants (36 boys and 44 girls) with T1D, who were aged 6–21 years and who attended the Diabetes and Metabolism Clinic of the 2nd Pediatric Department, University of Athens, “P & A Kyriakou” Children’s Hospital of Athens. Twenty (25%) children were above the 75th percentile regarding total levels of physical activity, while 40 (50%) and 20 (25%) were between the 25th and 75th percentile, as well as below the 25th percentile, respectively. In the group with an intermediate level of exercise, physical activity was negatively associated with the participant’s family situation (traditional, single parent, grandparent, with others, or by himself/herself) (p = 0.013), ferritin (p = 0.031), lipoprotein(a) [Lp(a)] (p = 0.016), and squared leptin levels (p = 0.040). Whereas in the groups with extreme vs. no exercise there was a negative association with the number of daily glucose measurements (p = 0.047). However, in the group with non-vigorous exercise, physical activity was positively associated with high density lipoprotein-c (HDL-c) levels (p = 0.048). The findings of this study are indicative of the beneficial role of exercise on children and adolescents with T1D, which is achieved by primarily improving their cardiometabolic profile through the amelioration of lipid profile [HDL-c, Lp(a)] and leptin levels, as well as by reducing chronic systemic inflammatory response (ferritin) and ultimately decreasing the overall diabetes morbidity

Immunoassay-Based Serum Hepcidin Reference Range Measurements in Healthy Children: Differences Among Age Groups

BackgroundHepcidin is a peptide hormone that plays a key role in regulating iron absorption from the small intestine and body iron distribution. Alterations in hepcidin concentrations have been associated with chronic inflammatory conditions or inherited diseases of iron metabolism. The aim of our study was to evaluate healthy children in order to define normal reference range of serum hepcidin concentrations. The universal use of a reliable commercial ELISA kit gives the ability to compare our results with those from previous studies. MethodsWe evaluated 180 healthy children (88 boys, mean age: 67.5539.26months, median: 60, range: 24-156months) aged 2-12 years, using an immunoassay kit. ResultsHepcidin median values were 46.94 ng/ml for boys and 46.79 ng/ml for girls. No significant differences were observed between boys and girls. There seem to be significantly higher values of hepcidin in older children (10-12 years old). This trend was constant and statistically significant in boys after gender and age group stratification. Although this trend was more prominent in girls, it was not statistically significant. ConclusionsThis study aims at setting up reference values for serum hepcidin concentrations in healthy pediatric population by using a well-established laboratory kit. The difference in hepcidin concentrations in older children could be attributed to different growth rates. Additionally, differences between values in adults and children could reflect alterations in iron metabolism between those two age groups

Serum Hepcidin and Ferritin to Iron Ratio in Evaluation of Bacterial Versus Viral Infections in Children A Single-center Study

Background: Differential diagnosis of childhood infections is important. Several biochemical indices steer diagnosis toward bacterial agents, although the data are often not definitive. Hepcidin is a central component of blood iron, and ferritin alterations occur during infections. We measured hepcidin changes and evaluated ferritin to iron ratio (FIR) in patients with suspected infections. Methods: We studied 69 children with infection and an equal number of matched controls during a 3-year period. A bacterial agent was demonstrated in 17 and a viral pathogen in 52 of the patients. Hematologic and biochemical tests were performed on all children including ferritin, iron and hepcidin. FIR was calculated and receiver operating characteristic curve analysis was performed to evaluate the best FIR cutoff value to discriminate between patients and controls and between patients with bacterial infections and viral infections. Results: Hepcidin, ferritin and FIR were significantly higher and iron values significantly lower in febrile patients than its controls. Patients with bacterial infection had significantly lower iron and higher FIR than those with viral infection. FIR had high accuracy discriminating patients from controls but only moderate accuracy discriminating bacterial from viral infected patients. Conclusions: If further studies with larger samples confirm these observations, FIR could be used as an inexpensive, rapid and easily performed complementary index for diagnosis of bacterial infections

Homozygosity of the Z-2 polymorphic variant in the aldose reductase gene promoter confers increased risk for neuropathy in children and adolescents with Type 1 diabetes

Background Diabetic neuropathy (DN) is the least recognized complication of diabetes mellitus and may start early in the course of the disease. Aldose reductase (AKR1B1) gene promoter Z-2/Z-2 polymorphism increases the expression of AKR1B1 enzyme and may contribute to DN. Subjects We evaluated 108 Type 1 diabetes (T1D) children and adolescents (mean +/- SD age: 13.5 +/- 3.46 years, disease duration: 5.3 +/- 3.4 years) and 150 healthy controls (age: 11.9 +/- 2.7 years). Methods In both groups, pupillary dilation (PD) in darkness, postural blood pressure test (PBPT), and vibration sensation thresholds (VST) in upper and lower limbs were estimated as indices of autonomic and peripheral neuropathy, respectively. Nerve conduction studies (NCS) were performed in patients as peripheral neuropathy index. The polymorphisms of AKR1B1 gene were evaluated using microsatellite (AC)n sequence Z. Results PBPT, PD, and VST impairments were more frequent in patient group compared with controls, while 38.6% of patients exhibited NCS abnormality. Gender, age, pubertal status, height, body mass index, diabetes duration, HbA1c, and anti-GAD titers were associated with neuropathy indices in patients. There was a strong correlation between PD and NCS in patients, while homozygous patients for Z-2 AKR1B1 gene polymorphism had higher prevalence of abnormal NCS (83.3% vs. 34.6%), PD (62.5% vs. 31.5%), and PBPT values compared with heterozygous or negative patients. Homozygous AKR1B1 status predicted PD, NCS, and PBPT variance, while PD, VST, NCS, and PBPT parameters accurately discriminated homozygous AKR1B1 patients. Conclusions Impaired indices of peripheral and autonomic DN were present in a significant proportion of young T1D patients. PD, VST, NCS, and PBPT parameters were simultaneously associated with homozygous state of AKR1B1 Z-2 gene polymorphism, implicating polyol metabolism with both autonomic and peripheral neuropathies