Skeletal growth and bone mineral acquisition in type 1 diabetic children; abnormalities of the GH/IGF-1 axis

Implication of Pappalysins and Stanniocalcins in the Bioavailability of IGF-I in Children With Type 1 Diabetes Mellitus

Context

Anomalies in the growth hormone (GH)/insulin-like growth factor (IGF) axis, are common in children with type 1 diabetes mellitus (T1DM), even in those reaching a normal or near-normal final height. However, concentrations of the IGF bioavailability regulatory factors (pappalysins [PAPP-As] and stanniocalcins [STCs]) have not been reported in children with T1DM.

Objective

To determine serum concentrations of PAPP-As and STCs in children at diagnosis of T1DM and after insulin treatment and the correlation of these factors with other members of the GH/IGF axis, beta-cell insulin reserve, auxology, and nutritional status.

Methods

A single-center prospective observational study including 47 patients (59.5% male), with T1DM onset at median age of 9.2 years (interquartile range: 6.3, 11.9) was performed. Blood and anthropometric data were collected at diagnosis and after 6 and 12 months of treatment.

Results

At 6 and 12 months after T1DM diagnosis, there was improvement in the metabolic control (decrease in glycated hemoglobin [HbA1c] at 12 months -3.66 [95% CI: -4.81, -2.05], P = .001), as well as in body mass index SD and height SD (not statistically significant). STC2 increased (P < .001) and PAPP-A2 decreased (P < .001) at 6 and 12 months of treatment onset (P < .001), which was concurrent with increased total IGF-I and IGF-binding protein concentrations, with no significant modification in free IGF-I concentrations. HbA1c correlated with PAPP-A2 (r = +0.41; P < .05) and STC2 (r = -0.32; P < .05).

Conclusion

Implementation of insulin treatment after T1DM onset modifies various components of the circulating IGF system, including PAPP-A2 and STC2. How these modifications modulate linear growth remains unknown.

Adaptation and validation of an artificial intelligence based digital radiogrammetry tool for assessing bone health of indian children and youth with type-1 diabetes

BACKGROUND AND OBJECTIVES

BoneXpert (BX) is an artificial intelligence software used primarily for bone age assessment. Besides, it can also be used to screen for bone health using the digital radiogrammetry tool called bone health index (BHI) for which normative reference values available are calculated from healthy European children. Due to ethnic difference in bone geometry, in a previous study, we generated reference curves based on healthy Indian children. The objectives of this study were: 1) To assess and compare bone health of Indian children with Type 1 diabetes (T1D) using both European and Indian BHI SDS reference data and 2) To identify determinants of poor bone health in Indian children and youth with T1D by using BHI tool (based on BHI-SDS Indian reference data) of BX.

METHOD

The BHI was assessed retrospectively in 1159 subjects with T1D using digitalised left-hand x-rays and SDS were computed using European and Indian data. The demographic, anthropometric, clinical, biochemistry, dual x-ray absorptiometry (DXA) data and peripheral quantitative computed tomography (pQCT) data collection were performed using standard protocols and were extracted from hospital records.

RESULTS

The BHI correlated well with DXA and pQCT parameters in subjects with T1D. BHI-SDS calculated using Indian reference data had better correlation with height and DXA parameters. 8.6% study participants had low (less than -2) BHI-SDS (Indian), with height SDS having significant effect. Subjects with low BHI-SDS were older, shorter and had higher duration of diabetes. They also had lower IGF1 and vitamin D concentrations, bone mineral density, and trabecular density. Female gender, increased duration of illness, poor glycaemic control, and vitamin D deficiency/insufficiency were significant predictors of poor BHI-SDS.

CONCLUSION

Our study highlights the utility of digital radiogrammetry AI tool to screen for bone health of children with T1D and demonstrates and highlights the necessity of interpretation using ethnicity specific normative data.

H. pylori infection and osteoporosis: a large-scale observational and mendelian randomization study

PURPOSE

There is controversy concerning the relationship between Helicobacter pylori (H. pylori) infection and osteoporosis. This study is to examine the causal relationship between H. pylori infection and osteoporosis and to analyze the potential mechanism underlying the relationship.

METHODS

The clinical data of H. pylori infection and bone mineral density from patients or physical examiner with good general condition in our hospital between September 2019 and September 2020 were retrospectively collected. The relationship between H. pylori infection and osteoporosis was compared and analyzed, using logistic regression to examine the potential mechanism underlying the association. To investigate the causal effects of H. pylori infection and osteoporosis, we conducted a two-sample bidirectional Mendelian randomization (MR) analysis.

RESULTS

A total of 470 patients were positive for H. pylori, with a detection rate of 52.22%. It was found that age, SBP, FPG, DBP, ALB, LDL-C, hs-CRP, and OC were positively correlated with osteoporosis, while negative correlations were observed with BMI, LYM, ALB, TP, TG, HDL-C, SCr, UA, and VitD. After stratified analysis of sex and age, it was found that there was a significant correlation between H. pylori infection and osteoporosis. The levels of SBP, ALP, FPG, LDL-C, hs-CRP, and OC in both H. pylori-positive group and osteoporosis group were higher than those in the H. pylori-negative group while the levels of BMI, ALB, TP, HDL-C, SCr, UA, and VitD in the positive group were significantly lower than those in the negative group. Logistic regression analyses with gender and age showed that ALB, FPG, HDL-C, and VitD were common risk factors for osteoporosis and H. pylori infection. In the MR analysis, the IVW results found a positive effect of H. pylori infection on osteoporosis (OR = 1.0017, 95% CI: 1.0002-1.0033, P = 0.0217). Regarding the reverse direction analysis, there was insufficient evidence to prove the causal effects of osteoporosis on H. pylori infection.

CONCLUSION

Our study provides evidence for causal effects of H. pylori infection on osteoporosis. H. pylori may affect osteoporosis through serum albumin, high-density lipoprotein, fasting blood glucose and vitamin D.

Final height in children and adolescents with type 1 diabetes mellitus: A systematic review and meta-analysis

PURPOSE

Considering the high prevalence of type 1 diabetes mellitus (T1DM) together with the importance of improved physical growth and the significance of promoting healthcare quality among T1DM children, this meta-analysis aims to determine mean final height in this population group.

METHODS

We systematically searched PubMed, EMBASE, Web of Science, Scopus, and Cochrane databases for all studies published until May 2023 and reviewed references of published articles. Meta-analytic procedures were used to estimate the effect size (mean final height Z-score) among T1DM children in a random effects model. Significance values, weighted effect sizes, 95% CIs, and tests of homogeneity of variance were calculated. The included studies consisted of data from 3274 patients.

RESULTS

The mean final height Z-score for T1DM children was -0.201 (n = 25 studies, 95% CI: -0.389, -0.013; I2 = 97%), -0.262 in males (n = 20 studies, 95% CI: -0.539, 0.015, I2 = 97.1%), and -0.218 in females (n = 18 studies, 95% CI: -0.436, 0, I2 = 94.2%). The non-significant negative association between age at diagnosis, HbA1c levels, and final height Z-score is suggested by the findings of the univariate meta-regression.

CONCLUSION

Our findings indicated that children with T1DM have impaired linear growth and that monitoring of growth in these patient populations is an important issue in the management of T1DM. Due to a scarcity of studies providing data on the relationship between uncontrolled diabetes (increased HbA1c) and early diagnosis and final height, further investigation is warranted to determine whether there is indeed a correlation. Consequently, any conclusion regarding the association between uncontrolled diabetes (elevated HbA1c), early diagnosis of T1DM, and the increased risk of impaired linear growth or final height remains uncertain.

Genetic evidence for the causal association between type 1 diabetes and the risk of polycystic ovary syndrome

BACKGROUND

Accumulating observational studies have identified associations between type 1 diabetes (T1D) and polycystic ovary syndrome (PCOS). Still, the evidence about the causal effect of this association is uncertain.

METHODS

We performed a two-sample Mendelian randomization (MR) analysis to test for the causal association between T1D and PCOS using data from a large-scale biopsy-confirmed genome-wide association study (GWAS) in European ancestries. We innovatively divided T1D into nine subgroups to be analyzed separately, including: type1 diabetes wide definition, type1 diabetes early onset, type 1 diabetes with coma, type 1 diabetes with ketoacidosis, type 1 diabetes with neurological complications, type 1 diabetes with ophthalmic complications, type 1 diabetes with peripheral circulatory complications, type 1 diabetes with renal complications, and type 1 diabetes with other specified/multiple/unspecified complications. GWAS data for PCOS were obtained from a large-scale GWAS (10,074 cases and 103,164 controls) for primary analysis and the IEU consortium for replication and meta-analysis. Sensitivity analyses were conducted to evaluate heterogeneity and pleiotropy.

RESULTS

Following rigorous instrument selection steps, the number of SNPs finally used for T1D nine subgroups varying from 6 to 36 was retained in MR estimation. However, we did not observe evidence of causal association between type 1 diabetes nine subgroups and PCOS using the IVW analysis, MR-Egger regression, and weighted median approaches, and all P values were > 0.05 with ORs near 1. Subsequent replicates and meta-analyses also yielded consistent results. A number of sensitivity analyses also did not reveal heterogeneity and pleiotropy, including Cochran's Q test, MR-Egger intercept test, MR-PRESSO global test, leave-one-out analysis, and funnel plot analysis.

CONCLUSION

This is the first MR study to investigate the causal relationship between type 1 diabetes and PCOS. Our findings failed to find substantial causal effect of type 1 diabetes on risk of PCOS. Further randomized controlled studies and MR studies are necessary.

Effects of Type 1 Diabetes Mellitus on Linear Growth: A Comprehensive Review

Type 1 diabetes mellitus (T1DM) has a significant effect on the growth of children. The disease has a negative effect on growth when considered in relation to the time period and metabolic control. Studies in this review have suggested debilitated growth in children with T1DM and have a few anomalies in the growth hormone (GH)-insulin-like growth factor-1 (IGF-1) axis when compared to fit children. Some studies show that children with T1DM were taller before the onset of the disease and during early diagnosis. Moreover, the linear growth depends on the interaction between the gonadotropin hormone, luteinizing hormone (LH), follicle-stimulating hormone (FSH), and sex steroid hormones axis and GH-IGF-1; there's a rise in GH during puberty, which has an effect on the estrogen and testosterone, which leads to the pulsatile secretion of GH, this increment leads to insulin resistance. These studies suggest short stature in girls, and some suggest in both. The final height in boys was unchanged, but a slight decline was observed in girls. This review aims to provide the latest understanding of impaired height in children with T1DM. The most accepted and effective treatment of impaired growth is the administration of long-acting insulin or continuous rapid-acting insulin. However, height was affected by the administration of good basal insulin at puberty and was unaffected by the continuous subcutaneous insulin injection. Hence, new technologies are the therapeutic regimen in children, especially the prepubertal age group; it will be interesting to see their effects on growth patterns in these children with T1DM.

Role of glucose variability on linear growth in children with type 1 diabetes

OBJECTIVE

Linear growth is impaired in children with type 1 diabetes (T1D) and poor metabolic control. A good metabolic control is a key therapeutic goal to prevent vascular complications and also to ensure appropriate anthropometric development during childhood. In this study, we aimed to identify and characterize the effects of glycemic variability on linear growth in children with T1D.

METHODS

Data from 144 prepubertal children with T1D were evaluated. Anthropometric measurements (weight, weight-SDS, height, height-SDS, BMI, BMI-SDS) were collected and glycosylated hemoglobin (HbA1c) was measured at admission and every 4 months over a 2-year period. Glycemic variability indexes (glycemic coefficient of variation (CV), glycemic CV percentage (CV%), and the product between HbA1c-mean and HbA1c-SDS/100 (M*SDS-HbA1c/100)) were calculated. According to height-SDS changes after 2 years of follow-up, the study population was divided into three tertile groups and differences across groups were investigated for variables of interest.

RESULTS

The three groups were similar in terms of age, gender, and follow-up period. After 2 years, all prepubertal children showed a significant positive trend of anthropometric data. Across the three tertile groups, HbA1c-SDS, CV, CV%, and M*SDS-HbA1c significantly decreased from the first to the third tertile of height-SDS. During follow-up, children with lower Δheight-SDS values reported higher values of HbA1c-SDS, CV, CV%, and M*SDS-HbA1c than subjects with higher linear growth.

CONCLUSIONS

Glycemic variability correlates with linear growth in children with T1D. Low glycemic variability indexes were reported in higher height-SDS tertiles. Δheight-SDS is inversely correlated with glycemic CV, CV%, and M*SDS-HbA1c.

IGF1 deficiency integrates stunted growth and neurodegeneration in Down syndrome

Down syndrome (DS), the genetic condition caused by trisomy 21 (T21), is characterized by stunted growth, cognitive impairment, and increased risk of diverse neurological conditions. Although signs of lifelong neurodegeneration are well documented in DS, the mechanisms underlying this phenotype await elucidation. Here we report a multi-omics analysis of neurodegeneration and neuroinflammation biomarkers, plasma proteomics, and immune profiling in a diverse cohort of more than 400 research participants. We identified depletion of insulin growth factor 1 (IGF1), a master regulator of growth and brain development, as the top biosignature associated with neurodegeneration in DS. Individuals with T21 display chronic IGF1 deficiency downstream of growth hormone production, associated with a specific inflammatory profile involving elevated tumor necrosis factor alpha (TNF-α). Shorter children with DS show stronger IGF1 deficiency, elevated biomarkers of neurodegeneration, and increased prevalence of autism and other conditions. These results point to disruption of IGF1 signaling as a potential contributor to stunted growth and neurodegeneration in DS.

Roles of Gut Microbiome in Bone Homeostasis and Its Relationship with Bone-Related Diseases

Simple Summary

In recent years, there has been increasing evidence that communication between the skeletal system and the gut microbiome (GM) can influence bone health and that the GM is a key regulator of bone homeostasis. Here, we review the roles of GM in bone homeostasis. In addition, the relationship between GM composition and selected bone-related diseases (osteoporosis, osteoarthritis, rheumatoid arthritis, diabetes mellitus, obesity and bone cancer) is presented. It is also emphasized that a probiotic supplementation can play an important role in suppressing the symptoms of each of these diseases.

Abstract

The extended microbial genome—the gut microbiome (GM)—plays a significant role in host health and disease. It is able to influence a number of physiological functions. During dysbiosis, GM is associated with the development of various chronic diseases with impaired bone quality. In general, GM is important for bone homeostasis and can affect it via several mechanisms. This review describes the roles of GM in bone homeostasis through influencing the immune and endocrine functions, short-chain fatty acids production, calcium absorption and the gut–brain axis. The relationship between GM composition and several bone-related diseases, specifically osteoporosis, osteoarthritis, rheumatoid arthritis, diabetes mellitus, obesity and bone cancer, is also highlighted and summarized. GM manipulation may become a future adjuvant therapy in the prevention of many chronic diseases. Therefore, the beneficial effects of probiotic therapy to improve the health status of individuals with aforementioned diseases are provided, but further studies are needed to clearly confirm its effectiveness. Recent evidence suggests that GM is responsible for direct and indirect effects on drug efficacy. Accordingly, various GM alterations and interactions related to the treatment of bone-related diseases are mentioned as well.

Increase in Bone Mass Before Onset of Type 1 Diabetes Mellitus in Rats

BACKGROUND/AIM

The typical insulin deficiency in type 1 diabetes mellitus has general effects on metabolism and also affects bone quality.

MATERIALS AND METHODS

Two diabetic rat lines (BB/OK; BB.6KWR) and two non-diabetic rat strains (KWR and BB.14+18KWR), as control group, were included in the study. Bone mineral density, bone mineral content and body structure measurements were performed. The measurements took place before the onset of diabetes mellitus Results: A comparison of the groups showed increased bone density values of the diabetic rats in relation to the control groups. A new finding of increased bone density in the diabetic rats occurs.

CONCLUSION

Diabetic rats showed no osteoporotic bone metabolism before the onset of clinically relevant type 1 diabetes mellitus, but rather increased bone metabolic activity.

A new ex vivo model of the bone tissue response to the hyperglycemic environment - The embryonic chicken femur organotypic culture in high glucose conditions

Diabetes mellitus (DM) embrace a group of chronic metabolic conditions with a high morbidity, causing deleterious effects in different tissues and organs, including bone. Hyperglycemia seems to be one of the most contributing etiological factors of bone-related alterations, altering metabolic functionality and inducing morphological adaptations. Despite the established models for the assessment of bone functionality in hyperglycemic conditions, in vitro studies present a limited representativeness given the imperfect cell-cell and cell-matrix interactions, and restricted three-dimensional spatial arrangement; while in vivo studies raise ethical issues and offer limited mechanistic characterization, given the modulatory influence of many systemic factors and/or regulatory systems. Accordingly, the aim of this study is to establish and characterize an innovative ex vivo model of the bone tissue response to hyperglycemia, reaching hand of the organotypic culture of embryonic chicken femurs in high glucose conditions, showcasing the integrative responsiveness of the model regarding hyperglycemia-induced alterations. A thorough assessment of the cellular and tissue functionality was further conducted. Results show that, in high glucose conditions, femurs presented an increased cell proliferation and enhanced collagen production, despite the altered protein synthesis, substantiated by the increased carbonyl content. Gene expression analysis evidenced that high glucose levels induced the expression of pro-inflammatory and early osteogenic markers, further impairing the expression of late osteogenic markers. Furthermore, the tissue morphological organization and matrix mineralization were significantly altered by high glucose levels, as evidenced by histological, histochemical and microtomographic evaluations. Attained data is coherent with acknowledged hyperglycemia-induced bone tissue alterations, validating the models' effectiveness, and evidencing its integrative responsiveness regarding cell proliferation, gene and protein expression, and tissue morpho-functional organization. The assessed ex vivo model conjoins the capability to access both cellular and tissue outcomes in the absence of a systemic modulatory influence, outreaching the functionality of current experimental in vitro and in vivo models of the diabetic bone condition.

Prevalence of Vertebral Fractures in Adults With Type 1 Diabetes: DenSiFy Study (Diabetes Spine Fractures)

CONTEXT

Vertebral fracture (VF) prevalence up to 24% has been reported among young people with type 1 diabetes (T1D). If this high prevalence is confirmed, individuals with T1D could benefit from preventative VF screening.

OBJECTIVE

We compared the prevalence of VFs between adults with T1D and nondiabetic controls.

METHODS

This cross-sectional study included 127 adults with T1D, and 65 controls with a similar age, sex, and BMI distribution, from outpatient clinics of 2 tertiary care centers. Vertebral fracture assessment (VFA) by dual-energy x-ray absorptiometry (DXA) was used for prevalent VFs. The modified algorithm-based qualitative (mABQ) method was applied. Bone mineral density (BMD) and trabecular bone score (TBS) were assessed by DXA. Serum bone turnover markers and sclerostin were measured in a subgroup of participants.

RESULTS

Participants with T1D (70 women, 57 men) had a mean age of 42.8 ± 14.8 years, median diabetes duration of 25.8 (15.8-34.4) years, mean BMI of 26.6 ± 5.4 kg/m2 and mean HbA1c over the past 3 years of 7.5 ± 0.9%. Controls (35 women, 30 men) had mean age of 42.2 ± 15.9 years and mean BMI of 26.1 ± 5.1 kg/m2. VF prevalence was comparable between groups (2.4% vs 3.1%, P = 0.99). TBS, BMD at the total hip and femoral neck, and bone formation and resorption markers were lower while sclerostin levels were similar in participants with T1D vs controls.

CONCLUSION

Our VFA results using the mABQ method do not confirm increased prevalence of VFs in men and women with relatively well-controlled T1D.

Disruption of the circadian clock component BMAL1 elicits an endocrine adaption impacting on insulin sensitivity and liver disease

SignificanceWhile increasing evidence associates the disruption of circadian rhythms with pathologic conditions, including obesity, type 2 diabetes, and nonalcoholic fatty liver diseases (NAFLD), the involved mechanisms are still poorly described. Here, we show that, in both humans and mice, the pathogenesis of NAFLD is associated with the disruption of the circadian clock combined with perturbations of the growth hormone and sex hormone pathways. However, while this condition protects mice from the development of fibrosis and insulin resistance, it correlates with increased fibrosis in humans. This suggests that the perturbation of the circadian clock and its associated disruption of the growth hormone and sex hormone pathways are critical for the pathogenesis of metabolic and liver diseases.

Oral Health Status of Children Living with Type 1 Diabetes Mellitus

Background: Diabetes is a well-known predisposing factor for oral diseases, so prevention in an early age is mandatory. Objective: To provide oral screening for children living with type 1 diabetes. We aimed to investigate the oral and general health indexes of T1DM children and compare these data to healthy siblings and controls. Methods: In this cross-sectional study, 120 DM patients and 78 siblings, thereafter 80 DM children and 95 controls, took part. A detailed questionnaire, panoramic radiographs, and lateral cephalograms were obtained in every orthodontic consultation. We used Pearson’s chi-square test for statistical analysis and compared the data of the study and control groups. Results: The oral health values of DM children were significantly better (DMF-T 0.83–1.3) than the national average (3.8–4.5). A total of 75% (n = 60) of the children needed orthodontic treatment for orthodontic or skeletal anomalies. The prevalence of skeletal anomalies was significantly (p < 0.05) higher among patients with diabetes mellitus (DM) than in the control group. The frequency of coeliac disease was significantly elevated compared to any literature data (1–3.5%) in the study (15%) and in the control sibling group (13%). Conclusions: Co-morbidities such as CD should get more attention as a prognostic factor for a future higher incidence of diabetes. T1DM children can be motivated and health-conscious patients with excellent oral hygiene and dental status. Orthodontic treatment can help eliminate the oral complications of DM. Special diabetes ambulances may help provide oral care for patients with DM.

Bone Density, Geometry, and Mass by Peripheral Quantitative Computed Tomography and Bone Turnover Markers in Children with Diabetes Mellitus Type 1

BACKGROUND

The type 1 diabetes mellitus (T1DM) is a chronic systemic autoimmune-mediated disease characterised by the insulin deficiency and hyperglycaemia. Its deleterious effect on bones concerns not only bone mass, density, and fracture risk but also may involve the linear growth of long bones. Studies on the lower leg in children with T1DM by pQCT have generated conflicting results, and most of the studies published so far focused only on a selected features of the bone. An additional information about growth, modelling, and remodelling processes can be gathered by the bone turnover marker measurement. The objective of the study was to evaluate bone mineral density, mass, and geometry using peripheral quantitative computed tomography as well as bone turnover markers in the patients with type 1 diabetes mellitus. Material and Methods. Bone mineral density, mass, and geometry on the lower leg using peripheral quantitative computed tomography and serum osteocalcin (OC) and carboxyterminal cross-linked telopeptide of type 1 collagen (CTx) were measured in 35 adolescents with T1DM (15 girls) aged 12.3-17.9 yrs. The results were compared to age- and sex-adjusted reference values for healthy controls.

RESULTS

Both sexes reveal lower than zero Z-scores for lower leg 66% total cortical bone cross-sectional area to muscle cross-sectional area ratio (-0.97 ± 1.02, p = 0.002517 and -0.98 ± 1.40, p = 0.007050, respectively) while tibia 4% trabecular bone density Z-score was lowered in boys (-0.67 ± 1.20, p = 0.02259). In boys in Tanner stage 5 bone mass and dimensions were diminished in comparison to Tanner stages 3 and 4, while in girls, such a phenomenon was not observed. Similarly, bone formation and resorption were decreased in boys but not in girls. Consistently, bone turnover markers correlated positively with bone size, dimensions, and strength in boys only.

CONCLUSIONS

T1DM patients revealed a decreased ratio of cortical bone area/muscle area, reflecting disturbed adaptation of the cortical shaft to the muscle force. When analyzing bone mass and dimensions, boys in Tanner stage 5 diverged from "less-mature" individuals, which may suggest that bone development in these individuals was impaired, affecting all three: mass, size, and strength. Noted in boys, suppressed bone metabolism may result in impairment of bone strength because of inadequate repair of microdamage and accumulation of microfractures.

Good glycemic control at puberty in boys with type 1 diabetes is important for final height

BACKGROUND

Poor glycemic control in children with type 1 diabetes (T1D) may hinder sexual development and the associated growth spurt. This study aims to identify factors that may affect the timing of puberty, total pubertal growth (TPG), and final height (F-Ht) in boys with T1D.

METHODS

This was a retrospective longitudinal study of 68 boys diagnosed with T1D during 1996 to 2009, who were prepubertal at diagnosis and had completed puberty at the time of data collection. Data were accessed regarding anthropometric measurements, Tanner stage, and glycosylated hemoglobin (HbA1c) levels from diagnosis to F-Ht. F-Ht was compared to parental height and Israeli National Health Survey data.

RESULTS

The mean F-Ht standard deviation score (F-Ht-SDS) was lower than the mean Ht-SDS at diagnosis (P < .006) but similar to the mean target height SDS (P = .3) and to values from the national survey (P = .12). Mean HbA1c levels in the year preceding pubertal onset were associated with the age at onset of puberty (R = 0.33, P = .009) and inversely with TPG (R = -0.3, P = .03). Mean HbA1c levels during puberty were inversely associated with TPG (R = -0.26, P = .035) and F-Ht (R = -0.28, P = .02). Boys who presented with diabetic ketoacidosis at diagnosis were shorter than those who did not throughout the follow-up.

CONCLUSIONS

We found associations of age of pubertal onset, pubertal growth spurt, and F-Ht with target height and glycemic control before and during puberty. Targeted interventions to achieve optimal metabolic control during these time periods are needed for normal, timely puberty and for achieving optimal adult height within the genetic target height.

Comparison of quantitative ultrasound of calcaneus and dual energy X-ray absorptiometry in measuring bone density and predicting fractures in patients with diabetic polyneuropathy: A prospective cohort study

AIMS

Compare quantitative ultrasound (QUS) of calcaneus and dual energy X-ray absorptiometry (DXA) as measurements of bone density, calculate 20-year fracture incidence in patients with T1DM and T2DM and multiple complications, and compare the methods' predictive ability.

METHODS

Sixty-two hospital foot clinic patients with T1DM or T2DM and complications were followed (1995-2015; 610 person-years). Clinical assessments and QUS of calcaneus were performed on all at inclusion and DXA of the spine and femoral neck on a subgroup (n = 34). Fracture incidence was assessed at follow-up and compared to incidence in the general population. We evaluated the correlation between QUS of calcaneus and DXA (Pearson's correlation test) and the association between bone density and fracture incidence at follow-up (logistic regression).

RESULTS

Bone density (QUS of calcaneus) correlated with hip bone density (DXA). Incidence of all fractures (30/62 patients; 48%) and hip fractures (6/62 patients; 10%) was higher in patients than the general population. Twelve (19%) experienced foot fracture. QUS of calcaneus predicted hip, lower leg, and foot fractures; DXA did not.

CONCLUSIONS

Because QUS of calcaneus predicted fractures in patients with diabetes and multiple complications, it seems appropriate to test QUS of calcaneus as a fracture risk predictor in primary care.

[Diabetes mellitus and cancer: a system of insulin-like growth factors]

Diabetes mellitus and malignant tumors are among the most common and complex diseases. Epidemiological studies have shown a strong relationship between these pathologies. The causality of this relationship has not yet been unambiguously established, but a number of probable biological mechanisms have been proposed to explain it through the effects of hyperglycemia, hyperinsulinemia on the process of oncogenesis. An important role in this is played by the axis of insulin-like growth factors, their receptors and binding proteins (IGF / IGFR / IGFBP). The review provides data on the structural elements of the insulin / IGF / IGFR / IGFBP signaling axis and their internal relationships in diabetes mellitus and in the development of malignant tumors. Significant changes in the axis that occur during the formation of the diabetic environment prepare the background, which, under certain conditions, can lead to the stimulation or inhibition of tumor development. The considered signaling system, playing a significant role in the physiology of normal cells, often functions as a decisive factor in the survival of tumor cells, providing fine context-dependent regulation of many cellular processes associated with oncogenesis. However, despite many years of in-depth studies of the pathogenesis of diabetes mellitus and malignant tumors, the molecular mechanisms of the relationship between these pathologies are still largely unclear, and the internal heterogeneity of pathologies complicates research and interpretation of the results, leaving many questions.

Rethinking Fragility Fractures in Type 2 Diabetes: The Link between Hyperinsulinaemia and Osteofragilitas

Patients with type 2 diabetes mellitus (T2DM) and/or cardiovascular disease (CVD), conditions of hyperinsulinaemia, have lower levels of osteocalcin and bone remodelling, and increased rates of fragility fractures. Unlike osteoporosis with lower bone mineral density (BMD), T2DM bone fragility "hyperinsulinaemia-osteofragilitas" phenotype presents with normal to increased BMD. Hyperinsulinaemia and insulin resistance positively associate with increased BMD and fragility fractures. Hyperinsulinaemia enforces glucose fuelling, which decreases NAD+-dependent antioxidant activity. This increases reactive oxygen species and mitochondrial fission, and decreases oxidative phosphorylation high-energy production capacity, required for osteoblasto/cytogenesis. Osteocytes directly mineralise and resorb bone, and inhibit mineralisation of their lacunocanalicular space via pyrophosphate. Hyperinsulinaemia decreases vitamin D availability via adipocyte sequestration, reducing dendrite connectivity, and compromising osteocyte viability. Decreased bone remodelling and micropetrosis ensues. Trapped/entombed magnesium within micropetrosis fossilisation spaces propagates magnesium deficiency (MgD), potentiating hyperinsulinaemia and decreases vitamin D transport. Vitamin D deficiency reduces osteocalcin synthesis and favours osteocyte apoptosis. Carbohydrate restriction/fasting/ketosis increases beta-oxidation, ketolysis, NAD+-dependent antioxidant activity, osteocyte viability and osteocalcin, and decreases excess insulin exposure. Osteocalcin is required for hydroxyapatite alignment, conferring bone structural integrity, decreasing fracture risk and improving metabolic/endocrine homeodynamics. Patients presenting with fracture and normal BMD should be investigated for T2DM and hyperinsulinaemia.

Mechanisms of altered bone remodeling in children with type 1 diabetes

Bone loss associated with type 1 diabetes mellitus (T1DM) begins at the onset of the disease, already in childhood, determining a lower bone mass peak and hence a greater risk of osteoporosis and fractures later in life. The mechanisms underlying diabetic bone fragility are not yet completely understood. Hyperglycemia and insulin deficiency can affect the bone cells functions, as well as the bone marrow fat, thus impairing the bone strength, geometry, and microarchitecture. Several factors, like insulin and growth hormone/insulin-like growth factor 1, can control bone marrow mesenchymal stem cell commitment, and the receptor activator of nuclear factor-κB ligand/osteoprotegerin and Wnt-b catenin pathways can impair bone turnover. Some myokines may have a key role in regulating metabolic control and improving bone mass in T1DM subjects. The aim of this review is to provide an overview of the current knowledge of the mechanisms underlying altered bone remodeling in children affected by T1DM.

Supplementation of Morin Restores the Altered Bone Histomorphometry in Hyperglycemic Rodents via Regulation of Insulin/IGF-1 Signaling

Pathological mechanisms underlining diabetic bone defects include oxidative damage and insulin/IGF-1 imbalance. Morin is a bioflavonoid with antioxidant and anti-diabetic effects. This study evaluates morin's protective effects against altered bone histomorphometry in diabetic rats through assessing insulin/IGF-1 pathway as a potential mechanism. Diabetic animals were administered two morin doses (15 and 30 mg/kg) for 5 weeks. Different serum hepatic and renal functions tests were assessed. Bone density and histomorphometry in cortical and trabecular tissues were evaluated histologically. The expressions of insulin, c-peptide and IGF-1 were estimated. In addition, the enzymatic activities of the major antioxidant enzymes were determined. Diabetic-associated alterations in serum glucose, aminotransferases, urea and creatinine were attenuated by morin. Diabetic bone cortical and trabecular histomorphometry were impaired with increased fibrosis, osteoclastic functions, osteoid formation and reduced mineralization, which was reversed by morin; particularly the 30 mg/kg dose. Insulin/IGF-1 levels were diminished in diabetic animals, while morin treatment enhanced their levels significantly. Diabetes also triggered systemic oxidative stress noticeably. The higher dose (30 mg/kg) of morin corrected the endogenous antioxidant enzymatic activities in diabetic rats. Findings indicate the potential value of morin supplementation against hyperglycemia-induced skeletal impairments. Activation of insulin/IGF-1 signaling could be the underlining mechanism behind these effects.

Association between type 1 diabetes mellitus and reduced bone mineral density in children: a meta-analysis

In this meta-analysis, we analyzed 9 cross-sectional studies for an association between type 1 diabetes mellitus (T1DM) and bone mineral density (BMD) in children. We found that BMD Z-scores were significantly reduced in children with T1DM.

INTRODUCTION

Recent cross-sectional studies have examined how T1DM influences bone health in children and adolescents, but the relationship between T1DM and BMD remains unclear due to conflicting reports.

METHODS

In this meta-analysis, we systematically searched PubMed, Cochrane library, and Web of Science databases (for publications through March 12, 2020), and calculated weight mean difference (WMD) along with 95% confidence intervals (CI) using a random-effects model. Heterogeneity was evaluated using the I² method. The Newcastle-Ottawa Scale was used to assess the quality of the included studies.

RESULTS

Data were analyzed from 9 eligible studies, including a total of 1522 children and adolescents. These data were tested for an association between T1DM and BMD. This analysis found a significant decrease in BMD Z-score in the whole body (pooled WMD, - 0.47, 95% CI, - 0.92 to - 0.02, I² = 80.2%) and lumbar spine (pooled WMD, - 0.41, 95% CI, - 0.69 to - 0.12, I² = 80.3%) in children and adolescents with T1DM, which was consistent in published studies from Asia and South America, but inconsistent in the North America and Europe. Importantly, the differences in BMD Z-scores were independent of age, level of glucose control (HbA1c), and prepubertal stage. Sensitivity analyses did not modify these findings. Funnel plot and the Egger test did not reveal significant publication bias.

CONCLUSION

This meta-analysis suggests that T1DM may play a role in decreasing BMD Z-scores in the whole body and lumbar spine in children.

Skeletal Response to Insulin in the Naturally Occurring Type 1 Diabetes Mellitus Mouse Model

Patients with type 1 diabetes mellitus (T1DM) exhibit reduced BMD and significant increases in fracture risk. Changes in BMD are attributed to blunted osteoblast activity and inhibited bone remodeling, but these cannot fully explain the impaired bone integrity in T1DM. The goal of this study was to determine the cellular mechanisms that contribute to impaired bone morphology and composition in T1DM. Nonobese diabetic (NOD) mice were used, along with μCT, histomorphometry, histology, Raman spectroscopy, and RNAseq analyses of several skeletal sites in response to naturally occurring hyperglycemia and insulin treatment. The bone volume in the axial skeleton was found to be severely reduced in diabetic NOD mice and was not completely resolved with insulin treatment. Decreased bone volume in diabetic mice was associated with increased sclerostin expression in osteocytes and attenuation of bone formation indices without changes in bone resorption. In the face of blunted bone remodeling, decreases in the mineral:matrix ratio were found in cortical bones of diabetic mice by Raman microspectroscopy, suggesting that T1DM did not affect the bone mineralization process per se, but rather resulted in microenvironmental alterations that favored mineral loss. Bone transcriptome analysis indicated metabolic shifts in response to T1DM. Dysregulation of genes involved in fatty acid oxidation, transport, and synthesis was found in diabetic NOD mice. Specifically, pyruvate dehydrogenase kinase isoenzyme 4 and glucose transporter 1 levels were increased, whereas phosphorylated‐AKT levels were significantly reduced in diabetic NOD mice. In conclusion, in addition to the blunted bone formation, osteoblasts and osteocytes undergo metabolic shifts in response to T1DM that may alter the microenvironment and contribute to mineral loss from the bone matrix. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Molecular characterization and analysis of the association of growth hormone 1 gene with growth traits in Chinese indigenous yak (Bos grunniens)

This study aimed to investigate the effects of polymorphisms in growth hormone 1 (GH1) gene on the growth traits in Chinese indigenous yak. Using the polymerase chain reaction-restriction fragment length polymorphism (PCR-PFLP) approach, one novel single-nucleotide polymorphism (SNP), termed as g.1721G>A, was identified in the exon 4 of GH1 gene in 423 individuals of yak population. Based on the chi-square (χ²) test, the frequencies of g.1721G>A alleles agreed with Hardy-Weinberg equilibrium (HWE) (P < 0.05). A significant association was observed between this SNP and several growth traits (P < 0.01 or P < 0.05), in which the genotype GG exhibited the best values. The present study suggested that the identified SNP was a useful genetic marker for the improvement of growth traits in Chinese indigenous yak.

Increased longevity due to sexual activity in mole-rats is associated with transcriptional changes in the HPA stress axis

Sexual activity and/or reproduction are associated with a doubling of life expectancy in the long-lived rodent genus Fukomys. To investigate the molecular mechanisms underlying this phenomenon, we analyzed 636 RNA-seq samples across 15 tissues. This analysis suggests that changes in the regulation of the hypothalamic–pituitary–adrenal stress axis play a key role regarding the extended life expectancy of reproductive vs. non-reproductive mole-rats. This is substantiated by a corpus of independent evidence. In accordance with previous studies, the up-regulation of the proteasome and so-called ‘anti-aging molecules’, for example, dehydroepiandrosterone, is linked with enhanced lifespan. On the other hand, several of our results are not consistent with knowledge about aging of short-lived model organisms. For example, we found the up-regulation of the insulin-like growth factor 1/growth hormone axis and several other anabolic processes to be compatible with a considerable lifespan prolongation. These contradictions question the extent to which findings from short-lived species can be transferred to longer-lived ones.

Association between Insulin-Like Growth Factor-1 and Relative Skeletal Maturation: A Retrospective Cohort Study of Short Children and Adolescents

Objective

Delays in skeletal maturity are related to bone mass and fracture risk in children, but the factors that determine it are unknown. We aimed to identify the association between insulin-like growth factor-1 (IGF-1) and skeletal maturation before and after growth hormone (GH) treatment.

Methods

In this retrospective cohort study, we observed 783 short children and adolescents, 229 of whom received GH therapy. Skeletal maturation was assessed based on the difference between bone age (BA) and chronological age (CA) (noted as BA-CA). Anthropometric data and laboratory values were measured, and BA was evaluated using the Greulich and Pyle method.

Results

The delayed BA group was defined as BA‐CA < −2 SD (n = 457), and the occurrence rate of BA delay was 58.37%. A nonlinear relationship was observed between the IGF-1 standard deviation score (IGF-1 SDS) and BA-CA before and after GH therapy. Before GH therapy, there was a significant positive association between the IGF-1 SDS and BA-CA when the IGF-1 level was greater than -2 SDS (β 0.17, 95% CI 0.08, 027; P < 0.001). However, we did not observe a significant relationship between the IGF-1 SDS and BA-CA when the IGF-1 level was lower than -2 SDS (β 0.07, 95% CI -0.12, 0.26; P = 0.454). After GH therapy, there was a significant positive association between the IGF-1 SDS and BA-CA when the IGF-1 level was lower than 2 SDS (β 0.20, 95% CI 0.12, 028; P < 0.001). However, we did not observe a significant relationship between the IGF-1 SDS and BA-CA when the IGF-1 level was greater than 2 SDS (β -0.03, 95% CI -0.33, 0.27; P = 0.866).

Conclusion

BA is more delayed in short children and adolescents. There is a nonlinear relationship between IGF-1 and BA maturation in short children before and after GH treatment. These findings suggest that a low level of IGF-1 may contribute to BA delay in short children and adolescents.

Acute Hyperinsulinemia Alters Bone Turnover in Women and Men With Type 1 Diabetes

Type 1 diabetes (T1D) increases fracture risk across the lifespan. The low bone turnover associated with T1D is thought to be related to glycemic control, but it is unclear whether peripheral hyperinsulinemia due to dependence on exogenous insulin has an independent effect on suppressing bone turnover. The purpose of this study was to test the bone turnover marker (BTM) response to acute hyperinsulinemia. Fifty‐eight adults aged 18 to 65 years with T1D over 2 years were enrolled at seven T1D Exchange Clinic Network sites. Participants had T1D diagnosis between age 6 months to 45 years. Participants were stratified based on their residual endogenous insulin secretion measured as peak C‐peptide response to a mixed meal tolerance test. BTMs (CTX, P1NP, sclerostin [SCL], osteonectin [ON], alkaline phosphatase [ALP], osteocalcin [OCN], osteoprotegerin [OPG], osteopontin [OPN], and IGF‐1) were assessed before and at the end of a 2‐hour hyperinsulinemic‐euglycemic clamp (HEC). Baseline ON (r = −0.30, p = .022) and OCN (r = −0.41, p = .002) were negatively correlated with age at T1D diagnosis, but baseline BTMs were not associated with HbA1c. During the HEC, P1NP decreased significantly (−14.5 ± 44.3%; p = .020) from baseline. OCN, ON, and IGF‐1 all significantly increased (16.0 ± 13.1%, 29.7 ± 31.7%, 34.1 ± 71.2%, respectively; all p < .001) during the clamp. The increase in SCL was not significant (7.3 ± 32.9%, p = .098), but the decrease in CTX (−12.4 ± 48.9, p = .058) neared significance. ALP and OPG were not changed from baseline (p = .23 and p = .77, respectively). Baseline ON and SCL were higher in men, but OPG was higher in women (all p ≤ .029). SCL was the only BTM that changed differently in women than men. There were no differences in baseline BTMs or change in BTMs between C‐peptide groups. Exogenous hyperinsulinemia acutely alters bone turnover, suggesting a need to determine whether strategies to promote healthy remodeling may protect bone quality in T1D. © 2020 American Society for Bone and Mineral Research © 2020 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Potential applications for rhIGF-I: Bone disease and IGFI

Growth hormone (GH) and insulin like growth factor-I (IGFI) are key bone trophic hormones, whose rising levels during puberty are critical for pubertal bone accrual. Conditions of GH deficiency and genetic resistance impact cortical and trabecular bone deleteriously with reduced estimates of bone strength. In humans, conditions of undernutrition (as in anorexia nervosa (AN), or subsequent to chronic illnesses) are associated with low IGF-I levels, which correlate with disease severity, and also with lower bone mineral density (BMD), impaired bone structure and lower strength estimates. In adolescents and adults with AN, studies have demonstrated a nutritionally acquired GH resistance with low IGF-I levels despite high concentrations of GH. IGF-I levels go up with increasing body weight, and are associated with rising levels of bone turnover markers. In short-term studies lasting 6-10 days, recombinant human IGF-I (rhIGF-I) administration in physiologic replacement doses normalized IGF-I levels and increased levels of bone formation markers in both adults and adolescents with AN. In a randomized controlled trial in adults with AN in which participants were randomized to one of four arms: (i) rhIGF-I with oral estrogen-progesterone (EP), (ii) rhIGF-I alone, (iii) EP alone, or (iv) neither for 9 months, a significant increase in bone formation markers was noted in the groups that received rhIGF-I, and a significant decrease in bone resorption markers in the groups that received EP. The group that received both rhIGF-I and EP had a significant increase in bone density at the spine and hip compared to the group that received neither. Side effects were minimal, with no documented fingerstick glucose of <50 mg/dl. These data thus suggest a potential role for rhIGF-I administration in optimizing bone accrual in states of undernutrition associated with low IGF-I.

REG-O3 chimeric peptide combining growth hormone and somatostatin sequences improves joint function and prevents cartilage degradation in rat model of traumatic knee osteoarthritis

Objective

REG-O3 is a 24-aminoacid chimeric peptide combining a sequence derived from growth hormone (GH) and an analog of somatostatin (SST), molecules displaying cartilage repair and anti-inflammatory properties, respectively. This study aimed to investigate the disease-modifying osteoarthritis drug (DMOAD) potential of REG-O3 by analyzing its effect on pain, joint function and structure, upon injection into osteoarthritic rat knee joint.

Design

Osteoarthritis was induced in the right knee of mature male Lewis rats (n = 12/group) by surgical transection of the anterior cruciate ligament (ACLT) combined with partial medial meniscectomy (pMMx). Treatments were administered intra-articularly from fourteen days after surgery through three consecutive injections one week apart. The effect of REG-O3, solubilized in a liposomal solution and injected at either 5, 25 or 50 μg/50 μL, was compared to liposomal (LIP), dexamethasone and hyaluronic acid (HA) solutions. The study endpoints were the pain/function measured once a week throughout the entire study, and the joint structure evaluated eight weeks after surgery using OARSI score.

Results

ACLT/pMMx surgery induced a significant modification of weight bearing in all groups. When compared to liposomal solution, REG-O3 was able to significantly improve weight bearing as efficiently as dexamethasone and HA. REG-O3 (25 μg) was also able to significantly decrease OARSI histological global score as well as degeneration of both cartilage and matrix while the other treatments did not.

Conclusion

This study provides evidence of a remarkable protecting effect of REG-O3 on pain/knee joint function and cartilage/matrix degradation in ACLT/pMMx model of rat osteoarthritis. REG-O3 thus displays an interesting profile as a DMOAD.

Bone health and hyperglycemia in pediatric populations

The impact of prediabetes and diabetes on skeletal health in the context of increased risk of fragility fractures in adults has been studied recently. However, the prevalence of diabetes, overweight, and obesity have also increased in younger subjects. Current data concerning bone metabolism based on assessment of markers for bone turnover and of bone quality in diabetes patients in diverse age groups appears to be inconsistent. This review synthesizes the current data on the assessment of bone turnover based on the use of circulating bone markers recommended by international organizations; the effects of age, gender, and other factors on the interpretation of the data; and the effects of type 1 and type 2 diabetes as well as hyperglycemia on bone quality and turnover with particular emphasis on the pediatric population. Early intervention in the pediatric population is necessary to prevent the progression of metabolic disturbances that accompany prediabetes and diabetes in the context of common low vitamin D status that may interfere with bone growth.

Linear Growth in Children and Adolescents with Type 1 Diabetes Mellitus

Ensuring normal linear growth is one of the major therapeutic aims in the management of type one diabetes mellitus (T1DM) in children and adolescents. Many studies in the literature have shown that pediatric patients with T1DM frequently present some abnormalities in their growth hormone (GH)/insulin-like growth factor-1 (IGF-1) axis compared to their healthy peers. Data on the growth of T1DM children and adolescents are still discordant: Some studies have reported that T1DM populations, especially those whose diabetes began in early childhood, are taller than healthy pediatric populations at diagnosis, while other studies have not found any difference. Moreover, many reports have highlighted a growth impairment in T1DM patients of prepubertal and pubertal age, and this impairment seems to be influenced by suboptimal glycemic control and disease duration. However, the most recent data showed that children treated with modern intensive insulin therapies reach a normal final adult height. This narrative review aims to provide current knowledge regarding linear growth in children and adolescents with T1DM. Currently, the choice of the most appropriate therapeutic regimen to achieve a good insulin level and the best metabolic control for each patient, together with the regular measurement of growth parameters, remains the most important available tool for a pediatric diabetologist. Nevertheless, since new technologies are the therapy of choice in young children, especially those of pre-school age, it would be of great interest to evaluate their effects on the growth pattern of children with T1DM.

Earlier puberty in boys with type 1 diabetes mellitus compared to a simultaneously recruited group of control adolescents

BACKGROUND

Recent studies have suggested that there is an earlier age of onset of puberty in healthy boys. However, no study has determined the age of pubertal development in boys with type 1 diabetes (T1D) and compared the results with a simultaneously recruited group of healthy children.

OBJECTIVE

The aim of this study was to evaluate the age of pubertal events in boys with TD1 and determine whether the duration of diabetes, metabolic control or insulin dose are associated with the age of puberty in boys with T1D.

METHODS

Boys aged 7 to 19 years with T1D (n = 148, age 12.9 ± 3.0 years) and healthy boys recruited from schools (n = 388 controls, age 12.8 ± 2.2 years) were studied. A pediatric endocrinologist evaluated pubertal development.

RESULTS

Boys at genital Tanner stage 2 and the final stages of puberty (genital Tanner 4 and 5) were younger than the control group (P = 0.005, P = 0.003, and P = 0.015, respectively). Both groups of boys had a similar age of pubic Tanner stage development. There were no cases of pubertal delay observed in the T1D cohort. There was no association observed between metabolic control with pubertal timing. T1D adolescents had lower height-SDS than the C group at the final stages of puberty.

CONCLUSIONS

Boys with T1D who are treated with modern insulin therapy appear to have an earlier age of onset and an earlier age of final pubertal events than a simultaneously studied group of healthy children. These data suggest that pubertal delay is not a frequent problem for male T1D patients.

Forearm bone density, cross-sectional size and muscle cross-sectional area in adolescents with diabetes mellitus type 1 assessed by peripheral quantitative computed tomography

OBJECTIVES

The mechanical components of bone strength (size, shape and density) in adolescents with T1DM are not extensively studied.

METHODS

The studied group comprises 39 adolescents, aged 11,9-18,0 yrs. The bone and muscle properties were investigated at the forearm (66% and 4% site). All measurements were performed using pQCT method.

RESULTS

The mean Z-score calculated for the ratio of the total cortical bone cross-sectional area to muscle cross-sectional area at 66% was lower than zero in girls (-0,93+/-1,06; p=0,0042). Significant differences between Tanner stages were noted in boys for mean Z-scores for bone masses, cross-sectional dimensions and strength.

CONCLUSIONS

T1DM girls revealed a decreased ratio of cortical bone area/muscle area, reflecting disturbed adaptation of the cortical shaft to the muscle force. When the Z-scores of cortical shell dimensions were investigated, cases in Tanner stage 5 diverged from "less mature" individuals, which may suggests that bone shaft development in these individuals was impaired, affecting both size and strength.

Skeletal Status, Body Composition, and Glycaemic Control in Adolescents with Type 1 Diabetes Mellitus

BACKGROUND

Disturbed bone turnover, osteoporosis, and increased fracture risk are late complications of insulin-dependent diabetes mellitus. Little is known about how far and to what extent can glycaemic control of type 1 diabetes mellitus (T1DM) prevent disturbances of bone health and body composition during the growth and maturation period.

OBJECTIVE

The aim of this cross-sectional study was to compare the skeletal status outcomes and body composition between patients stratified by glycaemic control (1-year HbA1c levels) into well- and poorly-controlled subgroups in a population of T1DM adolescents, that is, <8% and ≥8%, respectively.

SUBJECTS AND METHODS

Skeletal status and body composition were evaluated in 60 adolescents with T1DM (53.3% female; mean aged: 15.1 ± 1.9 years; disease duration: 5.1 ± 3.9 years) using dual energy X-ray absorptiometry (GE Prodigy). The results were compared to age- and sex-adjusted reference values for healthy controls. The calculated Z-scores of different metabolic control subgroups were compared. Clinical data was also assessed.

RESULTS

As evidenced by Z-scores, patients with T1DM revealed a significantly lower TBBMD (total body bone mineral density), TBBMC (total body bone mineral content), S24BMD (bone mineral density of lumbar spine L2-L4), and TBBMC/LBM ratio (total body bone mineral content/lean body mass), but higher FM (fat mass) and FM/LBM ratio (fat mass/lean body mass) values compared to an age- and sex-adjusted general population. The subset (43.3% patients) with poor metabolic control (HbA1c ≥ 8%) had lower TBBMD, TBBMC, and LBM compared to respective values noted in the HbA1c < 8% group, after adjusting for confounders (mean Z-scores: -0.74 vs. -0.10, p = 0.037; -0.67 vs. +0.01, p = 0.026; and -0.45 vs. +0.20, p = 0.043, respectively). Additionally, we found a significant difference in the TBBMC/LBM ratio (relative bone strength index) between the metabolic groups (-0.58 vs. -0.07; p = 0.021). A statistically significant negative correlation between 1-year HbA1c levels and Z-scores of TBBMD, TBBMC, and LBM was also observed. In patients with longer disease duration, a significant negative correlation was established only for TBBMD, after adjusting for confounders. The relationships between densitometric values and age at onset of T1DM and sex were not significant and showed no relation to any of the analysed parameters of the disease course.

CONCLUSION

Findings from this study of adolescents with T1DM indicate that the lower Z-scores of TBBMD, TBBMC, and LBM as well as the TBBMC/LBM ratio are associated with increased HbA1c levels. Their recognition can be crucial in directing strategies to optimise metabolic control and improve diabetes management for bone development and maintenance in adolescents with T1DM.

FoxO1 Is Required for Most of the Metabolic and Hormonal Perturbations Produced by Hepatic Insulin Receptor Deletion in Male Mice

Insulin coordinates the complex response to feeding, affecting numerous metabolic and hormonal pathways. Forkhead box protein O1 (FoxO1) is one of several signaling molecules downstream of insulin; FoxO1 drives gluconeogenesis and is suppressed by insulin. To determine the role of FoxO1 in mediating other actions of insulin, we studied mice with hepatic deletion of the insulin receptor, FoxO1, or both. We found that mice with deletion of the insulin receptor alone showed not only hyperglycemia but also a 70% decrease in plasma insulin-like growth factor 1 and delayed growth during the first 2 months of life, a 24-fold increase in the soluble leptin receptor and a 19-fold increase in plasma leptin levels. Deletion of the insulin receptor also produced derangements in fatty acid metabolism, with a decrease in the expression of the lipogenic enzymes, hepatic diglycerides, and plasma triglycerides; in parallel, it increased expression of the fatty acid oxidation enzymes. Mice with deletion of both insulin receptor and FoxO1 showed a much more modest phenotype, with normal or near-normal glucose levels, growth, leptin levels, hepatic diglycerides, and fatty acid oxidation gene expression; however, lipogenic gene expression remained low. Taken together, these data reveal the pervasive role of FoxO1 in mediating the effects of insulin on not only glucose metabolism but also other hormonal signaling pathways and even some aspects of lipid metabolism.

Hypercalcaemic Pancreatitis, Adrenal Insufficiency, Autoimmune Thyroiditis and Diabetes Mellitus in a girl with Probable Sarcoidosis

INTRODUCTION

Sarcoidosis is a multisystemic granulomatous disease with diverse and often non-specific symptoms during childhood. The clinical manifestations sometimes include endocrinopathies related to sarcoid infiltration of various endocrine organs, but more commonly due to the associated autoimmune endocrine disorders. There are only a few reports of multiple autoimmune and non-autoimmune endocrine problems occurring simultaneously in patients with sarcoidosis. We report a girl with probable sarcoidosis who also had Hashimoto's thyroiditis, Type 1 diabetes (T1D) and secondary adrenal insufficiency.

CASE PRESENTATION

A 9-year-old girl previously diagnosed with autoimmune hypothyroidism and vitamin D deficiency, presented with hypercalcemic pancreatitis after initiating vitamin D supplementation that lead to a diagnosis of probable sarcoidosis. Secondary adrenal insufficiency and T1D were subsequently diagnosed. Her angiotensin converting enzyme levels on 2 occasions were 106 and 135 nmol/mL/min (normal range 10 - 43). All investigations conducted to exclude several infectious and malignant conditions that may mimic sarcoidosis were negative. The patient showed a good response to treatment with hydrocortisone, levothyroxine, insulin and methotrexate.

CONCLUSIONS

To our knowledge, ours is the youngest ever patient reported in the literature with sarcoidosis to develop multiple autoimmune and non-autoimmune endocrinopathies.