Iodine deficiency hypothyroidism in children in recent years: a re-emerging issue?

Summary: Iodine nutrition is a growing issue within the USA due to newer trends of non-iodized salts. There are no recent reviews looking at the current state of iodine deficiency-induced hypothyroidism in children in the USA. We performed a retrospective chart review at our tertiary pediatric endocrine clinic; four met the diagnostic criteria for iodine deficiency defined by a low urine iodine level. We further characterized severity of disease, risk factors, goiter, thyroid labs and antibodies. All cases had significant goiter and were diagnosed within the last 2 years. One case had iodine deficiency due to no iodized salt intake along with concurrent diagnosis of developmental delay and multiple food allergies, while others involved the use of non-iodized salts. Two cases had iodine deficiency along with autoimmunity. It is critical to obtain a dietary history for all patients who present with goiter and/or hypothyroidism. There may be a need to consider reevaluating current preventative measures for iodine deficiency, especially for certain vulnerable populations such as children who do not consume iodized salt. Learning points: In recent decades, iodine nutrition has become a growing concern due to changing dietary patterns and food manufacturing practices. A dietary history is crucial to obtain in children presenting with hypothyroidism and goiter, especially in children with restrictive diets due to behavioral concerns, developmental delays, or multiple food allergies. Of the 12 different types of salts commercially available, only table salt contains iodine in an appropriate amount; thus, individuals using specialty salts can develop mild to moderate iodine deficiency-related thyroid disease.

Clinical practice guidelines for the care of girls and women with Turner syndrome.

Turner syndrome (TS) affects 50 per 100 000 females. TS affects multiple organs through all stages of life, necessitating multidisciplinary care. This guideline extends previous ones and includes important new advances, within diagnostics and genetics, estrogen treatment, fertility, co-morbidities, and neurocognition and neuropsychology. Exploratory meetings were held in 2021 in Europe and United States culminating with a consensus meeting in Aarhus, Denmark in June 2023. Prior to this, eight groups addressed important areas in TS care: (1) diagnosis and genetics, (2) growth, (3) puberty and estrogen treatment, (4) cardiovascular health, (5) transition, (6) fertility assessment, monitoring, and counselling, (7) health surveillance for comorbidities throughout the lifespan, and (8) neurocognition and its implications for mental health and well-being. Each group produced proposals for the present guidelines, which were meticulously discussed by the entire group. Four pertinent questions were submitted for formal GRADE (Grading of Recommendations, Assessment, Development and Evaluation) evaluation with systematic review of the literature. The guidelines project was initiated by the European Society for Endocrinology and the Pediatric Endocrine Society, in collaboration with members from the European Society for Pediatric Endocrinology, the European Society of Human Reproduction and Embryology, the European Reference Network on Rare Endocrine Conditions, the Society for Endocrinology, and the European Society of Cardiology, Japanese Society for Pediatric Endocrinology, Australia and New Zealand Society for Pediatric Endocrinology and Diabetes, Latin American Society for Pediatric Endocrinology, Arab Society for Pediatric Endocrinology and Diabetes, and the Asia Pacific Pediatric Endocrine Society. Advocacy groups appointed representatives for pre-meeting discussions and the consensus meeting.

Vosoritide treatment for children with hypochondroplasia: a phase 2 trial.

Background: Hypochondroplasia is a rare autosomal dominant skeletal dysplasia due to activating variants in FGFR3. It presents with disproportionate short stature with a wide range of clinical severity. There are currently no approved medications to treat short stature in children with hypochondroplasia. Vosoritide is a C-type natriuretic peptide analog that was recently approved for improving growth in children with achondroplasia. We aimed to evaluate the safety and efficacy of vosoritide in children with hypochondroplasia. Methods: We conducted a single-arm, phase 2, open-label trial at a single centre in the USA and enrolled 26 children with hypochondroplasia. The trial consists of a 6-month observation period to establish a baseline annualized growth velocity followed by a 12-month intervention period during which vosoritide is administered daily via subcutaneous injection at a dose of 15 µg/kg/day. The trial's co-primary endpoints included the incidence of adverse events and the change from baseline in age-sex standardized annualized growth velocity and height standardized deviation score (SDS) after 12 months of treatment. This trial is registered with ClinicalTrials.gov (NCT04219007). Findings: Twenty-four participants with a mean age of 5.86 years received vosoritide therapy. The first participant was enrolled on August 4, 2020, and the final participant completed the 18-month trial on September 8, 2023. Vosoritide was well tolerated with no treatment-related serious adverse events. Injection site reactions occurred in 83.3% of participants. No participants discontinued therapy due to an adverse event. Annualized growth velocity increased by 2.26 standard deviations (SD) and height SDS increased by 0.36 SD during the treatment period versus the observation period. Hypochondroplasia specific height SDS increased by 0.38 SD. There was a 1.81 cm/year increase in absolute annualized growth velocity. Interpretation: Vosoritide was safe and effective in increasing growth velocity in children with hypochondroplasia. Efficacy was similar to what has been reported in children with achondroplasia. Funding: This study was supported by an investigator-initiated grant from BioMarin Pharmaceutical.

Anti-Mullerian hormone and spontaneous puberty in a diverse US Turner syndrome clinic cohort: A cross-sectional study.

OBJECTIVE: Serum Anti-Mullerian Hormone (AMH) concentrations have been proposed as a marker of spontaneous puberty and future fertility in Turner syndrome (TS). Gonadotropins during minipuberty may also provide a clue to ovarian function but there is insufficient data to inform utility in the routine clinical management of TS. Our objective was to describe the distribution of AMH in a cross-sectional cohort of patients in a TS specialty clinic, and correlate with spontaneous puberty and karyotype, as well as gonadotropins during the minipuberty of infancy in a smaller subset of patients aged 2-9 months. DESIGN: Retrospective chart review of patients seen in the TS clinic at Children's National Hospital from 1/1/2019 to 8/24/2022, to assess AMH and correlate with karyotype and spontaneous puberty. RESULTS: Among 114 patients (median age 9.6 year, 0.08-22 year), AMH values were detectable in only (40/104) 38%, and higher mean AMH (2.7 ± 0.95 ng/mL) was seen in mosaic 45,X/46,XX karyotype compared to 45,X (0.03 ± 0.14 ng/mL) (p < .001), and structurally abnormal-X karyotype (0.11 ± 0.5) (p = .0003). Mean AMH was higher (1.4 ± 1.6 ng/mL) among those with spontaneous menarche compared with spontaneous thelarche but no menarche. AMH was detectable in 2/10 during minipuberty in those with the lowest luteinizing hormone (LH). CONCLUSIONS: Our institutional data reflects a diverse cohort of patients seen in a TS specialty clinic in the United States, showing correlation of AMH with karyotype and spontaneous menarche, as well as description of gonadotropins during minipuberty highlighting their clinical relevance. Studies in larger, prospective longitudinal cohorts will help determine their predictive value and role in the care of TS.

Hormone Replacement Therapy after Pubertal Induction in Adolescents and Young Adults with Turner Syndrome: A Survey Study.

INTRODUCTION: Turner syndrome (TS) is associated with primary ovarian insufficiency (POI) and most adolescents and young adults (AYA) with TS require treatment with hormone replacement therapy (HRT). International consensus guidelines are unclear on the optimal formulation and dosing for HRT after pubertal induction. This study assessed current HRT practice patterns of endocrinologists and gynecologists in North America. METHODS: Email listserv members of the North American Society for Pediatric and Adolescent Gynecology (NASPAG) and the Pediatric Endocrine Society (PES) were invited to complete a 19-question survey to assess HRT treatment preferences for the management of POI after completion of pubertal induction in AYA with TS. Descriptive analysis and multinomial logistic regression to predict factors associated with preferred HRT are presented. RESULTS: 155 providers (79% pediatric endocrinology, 17% pediatric gynecology) completed the survey. Although 87% (135) reported confidence in prescribing HRT, only half (51%, 79) were aware of published guidelines. Factors significantly associated with preferred HRT included specialty (p = 0.032) and number of patients with TS seen every 3 months (p = 0.024). Gynecologists were 4 times less likely than endocrinologists to prefer hormonal contraceptives and 4 times more likely to favor transdermal estradiol dose of 100 µg/day as compared to lower doses. CONCLUSION: Although most endocrinologists and gynecologists report confidence in prescribing HRT to AYA with TS after pubertal induction, there are clear differences in provider preferences based on specialty and higher volume of patients with TS in their practice. Additional studies on comparative effectiveness of the HRT regimens and evidence-based guidelines are necessary for AYA with TS.

Inspiring New Science to Guide Healthcare in Turner Syndrome: Rationale, design, and methods for the InsighTS Registry.

Inspiring New Science to Guide Healthcare in Turner Syndrome (InsighTS) Registry is a national, multicenter registry for individuals with Turner syndrome (TS) designed to collect and store validated longitudinal clinical data from a diverse cohort of patients with TS. Herein, we describe the rationale, design, and approach used to develop the InsighTS registry, as well as the demographics of the initial participants to illustrate the registry's diversity and future utility. Multiple stakeholder groups have been involved from project conceptualization through dissemination, ensuring the registry serves the priorities of the TS community. Key features of InsighTS include recruitment strategies to facilitate enrollment of participants that appropriately reflect the population of individuals with TS receiving care in the US, clarity of data ownership and sharing, and sustainability of this resource. The registry gathers clinical data on diagnosis, treatment, comorbidities, health care utilization, clinical practices, and quality of life with the goal of improving health outcomes for this population. Future directions include multiple patient-centered clinical-translational research projects that will use the InsighTS platform. This thorough and thoughtful planning will ensure InsighTS is a valuable and sustainable resource for the TS community for decades to come.

Case report: Early molecular confirmation and sodium polystyrene sulfonate management of systemic pseudohypoaldosteronism type I.

Introduction: Type 1 pseudohypoaldosteronism (PHA) consists of resistance to aldosterone. Neonatal presentation is characterized by salt wasting, hyperkalemia, and metabolic acidosis with high risk of mortality. Type 1 PHA can be autosomal dominant (renal type 1) or autosomal recessive (systemic type 1). Renal PHA type 1 can be feasibly managed with salt supplementation; however, systemic PHA type 1 tends to have more severe electrolyte imbalance and can be more refractory to treatment. Case Presentation: We present a case of a 3-year-old girl with systemic PHA type 1, diagnosed and confirmed molecularly in infancy, who has been successfully managed with sodium polystyrene sulfonate decanted into feeds along with sodium supplementation. On day 5 of life, a full-term female infant presented to the ED for 2 days of non-bloody, non-bilious emesis, along with hypothermia to 94°F. Laboratory results were notable for hyponatremia (Na) of 127, hyperkalemia (K) of 7.9, and acidosis with bicarbonate level of 11.2. Genetic testing ordered within a week of life confirmed PHA type 1 with a homozygous pathogenic frameshift variant in SCNN1A c.575delA (p.Arg192GlyfsX57). Sodium polystyrene sulfonate and feeds were decanted until the age of 16 months, and she was also continued on NaCl supplementation. She was gradually transitioned to directly administered sodium polystyrene sulfonate without any electrolyte issues. She has overall done well after gastrostomy-tube (G-tube) placement without severe hyperkalemia even with several hospitalizations for gastrointestinal or respiratory illnesses. Discussion/Conclusion: A treatment approach to systemic PHA and sodium polystyrene sulfonate administration in neonates and infants is described.

Cell-free DNA screening positive for monosomy X: clinical evaluation and management of suspected maternal or fetal Turner syndrome.

Initially provided as an alternative to evaluation of serum analytes and nuchal translucency for the assessment of pregnancies at high risk of trisomy 21, cell-free DNA screening for fetal aneuploidy, also referred to as noninvasive prenatal screening, can now also screen for fetal sex chromosome anomalies such as monosomy X as early as 9 to 10 weeks of gestation. Early identification of Turner syndrome, a sex chromosome anomaly resulting from the complete or partial absence of the second X chromosome, allows medical interventions such as optimizing obstetrical outcomes, hormone replacement therapy, fertility preservation and support, and improved neurocognitive outcomes. However, cell-free DNA screening for sex chromosome anomalies and monosomy X in particular is associated with high false-positive rates and low positive predictive value. A cell-free DNA result positive for monosomy X may represent fetal Turner syndrome, maternal Turner syndrome, or confined placental mosaicism. A positive screen for monosomy X with discordant results of diagnostic fetal karyotype presents unique interpretation and management challenges because of potential implications for previously unrecognized maternal Turner syndrome. The current international consensus clinical practice guidelines for the care of individuals with Turner syndrome throughout the lifespan do not specifically address management of individuals with a cell-free DNA screen positive for monosomy X. This study aimed to provide context and expert-driven recommendations for maternal and/or fetal evaluation and management when cell-free DNA screening is positive for monosomy X. We highlight unique challenges of cell-free DNA screening that is incidentally positive for monosomy X, present recommendations for determining if the result is a true-positive, and discuss when diagnosis of Turner syndrome is applicable to the fetus vs the mother. Whereas we defer the subsequent management of confirmed Turner syndrome to the clinical practice guidelines, we highlight unique considerations for individuals initially identified through cell-free DNA screening.

New-Onset Primary Adrenal Insufficiency and Autoimmune Hypothyroidism in a Pediatric Patient Presenting with MIS-C.

INTRODUCTION: There is emerging speculation that the inflammatory state associated with SARS-CoV-2 infection may trigger autoimmune conditions, but no causal link is established. There are reports of autoimmune thyroiditis and adrenal insufficiency in adults post-COVID-19. We describe the first pediatric report of adrenal insufficiency and autoimmune hypothyroidism after COVID-19. CASE PRESENTATION: A 14-year-old previously healthy girl, with vitiligo, presented in shock following 1 week of fever, lethargy, diarrhea, and vomiting. Three weeks prior, she had congestion and fatigue and known familial exposure for COVID-19. Labs were remarkable for sodium 129 mmol/L, K 4.3 mmol/L, creatinine 2.9 mg/dL, hemoglobin 8.3 g/dL, and positive COVID-19 PCR and SARS-CoV-2 IgG. She was resuscitated with normal saline and required pressor support. EKG showed abnormal repolarization presumed secondary to myocarditis. She met the criteria for multisystem inflammatory syndrome in children (MIS-C), received intravenous immune globulin and IL-1R antagonist and was admitted for intensive care. Persistent hypotension despite improved inflammatory markers and undetectable cortisol led to initiation of hydrocortisone. She was then able to rapidly wean off pressors and hydrocortisone within 48 h. Thereafter, tests undertaken for persistent bradycardia confirmed autoimmune hypothyroidism with TSH 131 µU/mL, free T4 0.85 ng/dL, and positive thyroid autoantibodies. Basal and stimulated cortisol were <1 µg/dL on a standard 250 µg cosyntropin stimulation test, with baseline ACTH >1,250 pg/mL confirming primary adrenal insufficiency. Treatment was initiated with hydrocortisone, levothyroxine, and fludrocortisone. Adrenal sonogram did not reveal any hemorrhage and anti-adrenal antibody titers were positive. The family retrospectively reported oligomenorrhea, increased salt craving in the months prior, and a family history of autoimmune thyroiditis. The cytokine panel was notably different from other cases of MIS-C. CONCLUSION: This is the first pediatric report, to our knowledge, of primary adrenal insufficiency and hypothyroidism following COVID-19, leading to a unique presentation of autoimmune polyglandular syndrome type 2. The initial presentation was attributed to MIS-C, but the subsequent clinical course suggests the possibility of adrenal crisis. It remains unknown if COVID-19 had a causal relationship in triggering the autoimmune adrenal insufficiency and hypothyroidism.

The Care of Adolescents and Young Adults with Turner Syndrome: A Pediatric and Adolescent Gynecology Perspective.

Turner syndrome (TS) is caused by the absence of a part or whole X chromosome in a phenotypic female and has an estimated prevalence of 25-50/100,000 live-born females. The primary gynecologic manifestation of TS is primary ovarian insufficiency (POI), and the resulting hypoestrogenism and infertility are experienced by most individuals with TS. In this review, we summarize the recommendations for the care of adolescents and young adults with TS, with a focus on primary ovarian insufficiency in TS, hormone replacement therapy, fertility preservation, and pregnancy in TS.

Clinical Utility of Anti-Mullerian Hormone in Pediatrics.

CONTEXT: Anti-Mullerian hormone (AMH) was originally described in the context of sexual differentiation in the male fetus but has gained prominence now as a marker of ovarian reserve and fertility in females. In this mini-review, we offer an updated synopsis on AMH and its clinical utility in pediatric patients. DESIGN AND RESULTS: A systematic search was undertaken for studies related to the physiology of AMH, normative data, and clinical role in pediatrics. In males, AMH, secreted by Sertoli cells, is found at high levels prenatally and throughout childhood and declines with progression through puberty to overlap with levels in females. Thus, serum AMH has clinical utility as a marker of testicular tissue in males with differences in sexual development and cryptorchidism and in the evaluation of persistent Mullerian duct syndrome. In females, serum AMH has been used as a predictive marker of ovarian reserve and fertility, but prepubertal and adolescent AMH assessments need to be interpreted cautiously. AMH is also a marker of tumor burden, progression, and recurrence in germ cell tumors of the ovary. CONCLUSIONS: AMH has widespread clinical diagnostic utility in pediatrics but interpretation is often challenging and should be undertaken in the context of not only age and sex but also developmental and pubertal stage of the child. Nonstandardized assays necessitate the need for assay-specific normative data. The recognition of the role of AMH beyond gonadal development and maturation may usher in novel diagnostic and therapeutic applications that would further expand its utility in pediatric care.

Approach to the Patient: Safety of Growth Hormone Replacement in Children and Adolescents.

The use of recombinant human growth hormone (rhGH) in children and adolescents has expanded since its initial approval to treat patients with severe GH deficiency (GHD) in 1985. rhGH is now approved to treat several conditions associated with poor growth and short stature. Recent studies have raised concerns that treatment during childhood may affect morbidity and mortality in adulthood, with specific controversies over cancer risk and cerebrovascular events. We will review 3 common referrals to a pediatric endocrinology clinic, followed by a summary of short- and long-term effects of rhGH beyond height outcomes. Methods to mitigate risk will be reviewed. Finally, this information will be applied to each clinical case, highlighting differences in counseling and clinical outcomes. rhGH therapy has been used for more than 3 decades. Data are largely reassuring, yet we still have much to learn about pharmaceutical approaches to growth in children and the lifelong effect of treatment.

Trajectories in estimated glomerular filtration rate in youth-onset type 1 and type 2 diabetes: The SEARCH for Diabetes in Youth Study.

AIMS: We sought to characterize the direction and associated factors of eGFR change following diagnosis of youth-onset type 1 and type 2 diabetes. METHODS: We assessed the direction of eGFR change at two visits (mean 6.6 years apart) in SEARCH, a longitudinal cohort study of youth-onset type 1 and type 2 diabetes. We used the CKiDCr-CysC equation to estimate GFR and categorized 'rising' and 'declining' eGFR as an annual change of ≥3 ml/min/1.73 m2 in either direction. Multivariable logistic regression evaluated factors associated with directional change in eGFR. RESULTS: Estimated GFR declined in 23.8% and rose in 2.8% of participants with type 1 diabetes (N = 1225; baseline age 11.4 years), and declined in 18.1% and rose in 15.6% of participants with type 2 diabetes (N = 160; baseline age 15.0 years). Factors associated with rising and declining eGFR (versus stable) in both type 1 and type 2 diabetes included sex, age at diagnosis, baseline eGFR and difference in fasting glucose between study visits. Additional factors in type 1 diabetes included time from baseline visit, HbA1c and body mass index. CONCLUSIONS: Over the first decade of diabetes, eGFR decline is more common in type 1 diabetes whereas eGFR rise is more common in type 2 diabetes.

Immunological Profile and Autoimmunity in Turner Syndrome.

Turner syndrome (TS), characterized by the partial or complete absence of an X-chromosome, provides a unique insight into the role of the X-chromosome and the immune system. While women have a 10-fold higher incidence of autoimmune disease (AD) compared with men, the risk in women with TS is thought to be further doubled. TS is associated with a propensity for a wide variety of ADs that increase in incidence across the life span. Isochromosome Xq as well as isolated Xp deletion karyotypes may predispose to higher rates of AD in TS suggesting the impact of X-chromosome gene dosage. It is likely, however, that epigenetic changes across the genome and the hormonal milieu may also have a profound impact on the immune profile in TS. This review explores the immune phenotype and the spectrum of ADs in TS. Genotype-phenotype correlations are presented with a brief overview of the genetic and hormonal underpinnings.

Nutritional Rickets Presenting as Chronic Episodic Extremity Pain in a 9-year-old with Autism.

Rickets due to vitamin D deficiency, typically presenting as bowed legs in toddlers, is uncommon in the modern era. We describe the case of a nine-year-old girl with autism and developmental delay who was evaluated for chronic intermittent extremity pain for more than one year prior to referral to the emergency department for hypocalcemia and increased alkaline phosphatase, which eventually led to the diagnosis of rickets confirmed by radiographic and laboratory findings. This report highlights the importance of the patient's history of developmental delay and autism in the evaluation and approach to limb pain, and discusses the appropriate diagnostic approach.

Current best practice in the management of Turner syndrome.

Turner syndrome (TS) is characterized by partial or complete loss of the second X-chromosome in phenotypic females resulting in a constellation of clinical findings that may include lymphedema, cardiac anomalies, short stature, primary ovarian failure and neurocognitive difficulties. Optimizing health care delivery is important to enable these individuals achieve their full potential. We review the current best practice management recommendations for individuals with TS focusing on the latest consensus opinion in regard to genetic diagnosis, treatment of short stature, estrogen supplementation, addressing psychosocial issues, as well screening for other comorbidities. A multidisciplinary approach and a well-planned transition to adult follow-up care will improve health care delivery significantly for this population.

Serum cystatin C in youth with diabetes: The SEARCH for diabetes in youth study.

AIMS: We compared cystatin C in youth with versus without diabetes and determined factors associated with cystatin C in youth with type 1 diabetes (T1D) and type 2 diabetes (T2D). METHODS: Youth (ages 12-19years) without diabetes (N=544) were ascertained from the NHANES Study 2000-2002 and those with T1D (N=977) and T2D (N=168) from the SEARCH for Diabetes in Youth Study. Adjusted means of cystatin C concentrations were compared amongst the 3 groups. Next, we performed multivariable analyses within the T1D and T2D SEARCH samples to determine the association between cystatin C and race, sex, age, diabetes duration, HbA1c, fasting glucose, and BMI. RESULTS: Adjusted cystatin C concentrations were statistically higher in NHANES (0.85mg/L) than in either the T1D (0.75mg/L) or T2D (0.70mg/L) SEARCH groups (P<0.0001). Fasting glucose was inversely related to cystatin C only in T1D (P<0.001) and BMI positively associated only in T2D (P<0.01) while HbA1c was inversely associated in both groups. CONCLUSIONS: Cystatin C concentrations are statistically higher in youth without diabetes compared to T1D or T2D, however the clinical relevance of this difference is quite small, especially in T1D. In youth with diabetes, cystatin C varies with BMI and acute and chronic glycemic control, however their effects may be different according to diabetes type.

Bone mineral density in patients with inherited bone marrow failure syndromes.

BackgroundPatients with inherited bone marrow failure syndromes (IBMFS) may have several risk factors for low bone mineral density (BMD). We aimed to evaluate the prevalence of low BMD in IBMFS and determine the associated risk factors.MethodsPatients with IBMFS with at least one dual-energy X-ray absorptiometry (DXA) scan were evaluated. Diagnosis of each IBMFS, Fanconi anemia (FA), dyskeratosis congenita, Diamond-Blackfan anemia, and Shwachman-Diamond syndrome was confirmed by syndrome-specific tests. Data were gathered on age, height, and clinical history. DXA scans were completed at the lumbar spine, femoral neck, and forearm. BMD was adjusted for height (HAZ) in children (age ≤20 years). Low BMD was defined as a BMD Z-score and HAZ ≤-2 in adults and children, respectively, in addition to patients currently on bisphosphonate therapy.ResultsNine of thirty-five adults (26%) and eleven of forty children (27%) had low BMD. Adults with FA had significantly lower BMD Z-scores than those with other diagnoses; however, HAZ did not vary significantly in children by diagnosis. Risk factors included hypogonadism, iron overload, and glucocorticoid use.ConclusionsAdults and children with IBMFS have high prevalence of low BMD. Prompt recognition of risk factors and management are essential to optimize bone health.

Chitosan nanofibers for transbuccal insulin delivery.

In this work, they aimed at producing chitosan based nanofiber mats capable of delivering insulin via the buccal mucosa. Chitosan was electrospun into nanofibers using poly(ethylene oxide) (PEO) as a carrier molecule in various feed ratios. The mechanical properties and degradation kinetics of the fibers were measured. Insulin release rates were determined in vitro using an ELISA assay. The bioactivity of released insulin was measured in terms of Akt activation in pre-adipocytes. Insulin permeation across the buccal mucosa was measured in an ex-vivo porcine transbuccal model. Fiber morphology, mechanical properties, and in vitro stability were dependent on PEO feed ratio. Lower PEO content blends produced smaller diameter fibers with significantly faster insulin release kinetics. Insulin showed no reduction in bioactivity due to electrospinning. Buccal permeation of insulin facilitated by high chitosan content blends was significantly higher than that of free insulin. Taken together, the work demonstrates that chitosan-based nanofibers have the potential to serve as a transbuccal insulin delivery vehicle. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1252-1259, 2017.