Approach to the Peripubertal Patient With Short Stature.

CONTEXT: The assessment and treatment of children with growth retardation is increasingly complex, and due to availability of targeted genetic sequencing, an ever-expanding number of conditions impeding growth are being identified. Among endocrine-related etiologies of short stature amenable to hormonal treatment, defects in the growth hormone (GH)-insulin-like growth factor I axis remain pre-eminent, with a multiplicity of disorders causing decreased secretion or insensitivity to GH action. Sex steroids in puberty increase epiphyseal senescence and eventual growth plate closure. This is mediated mostly via estrogen receptor (ER)α in males and females, effects that can greatly limit time available for growth. EVIDENCE ACQUISITION: Extensive literature review through PubMed and other search engines. EVIDENCE SYNTHESIS: Therapeutic strategies to be considered in peripubertal and pubertal children with disordered growth are here discussed, including daily and weekly GH, low-dose sex steroids, gonadotropin hormone releasing hormone (GnRH) analogues in combination with GH, aromatase inhibitors (AIs) alone and in combination with GH in boys. When used for at least 2 to 3 years, GnRH analogues combined with GH can result in meaningful increases in height. AIs used with GH permit puberty to progress in boys without hindrance, selectively decreasing estrogen, and resulting in taller height. With more than 20 years of cumulative experience in clinical use of these medications, we discuss the safety profile of these treatments. CONCLUSION: The approach of growth retardation in the peripubertal and pubertal years must consider the sex steroid milieu and the tempo of bone acceleration. Treatment of affected children in this period must be individualized.

The Structured Oral Examination: A Method to Improve Formative Assessment of Fellows in Pediatric Endocrinology.

OBJECTIVE: A structured oral exam (SOE) can be utilized as a formative assessment to provide high-quality formative feedback to trainees, but has not been adequately studied in graduate medical education. We obtained fellow and faculty perspectives on: 1) educational effectiveness, 2) feasibility/acceptability, and 3) time/cost of a SOE for formative feedback. METHODS: Four pediatric endocrinology cases were developed and peer-reviewed to generate a SOE. The exam was administered by faculty to pediatric endocrinology fellows individually, with feedback after each case. Fellow/faculty perspectives of the SOE were obtained through a questionnaire. Qualitative thematic analysis was utilized to analyze written comments generated by faculty and fellows. RESULTS: Seven of 10 pediatric endocrinology fellowship programs and all 18 fellows within those programs agreed to participate. Thematic analysis of fellow and faculty comments resulted in 5 perceived advantages of the SOE: 1) improved identification of clinically relevant knowledge deficits, 2) improved assessment of clinical reasoning, 3) immediate feedback/teaching, 4) assurance of adequate teaching/assessment of uncommon cases, and 5) more clinically relevant assessment. Mean time to administer one case was 15.8 minutes (2.0) and was mentioned as a potential barrier to implementation. Almost all fellows (17/18, 94%) and faculty (6/7, 86%) would recommend or would most likely recommend implementation of the SOE into their curriculum. CONCLUSIONS: The SOE utilized for formative feedback was perceived by fellows and faculty to have several educational advantages over current assessments and high acceptability. Objective educational advantages should be assessed on future studies of the SOE.

Impact of route of administration on genotoxic oestrogens concentrations using oral vs transdermal oestradiol in girls with Turner syndrome.

OBJECTIVE: The established link between oestrogen and breast cancer occurs via both oestrogen receptor (ER)-mediated and non ER-mediated mechanisms. The term genotoxic estrogens describes mutagenic metabolites, including oestrogen catechols and quinones, which have been linked to breast carcinogenesis in post-menopausal women. We aimed to assess whether the route of administration of 17ß oestradiol (E2 ) affects the accumulation of genotoxic oestrogen metabolites in a model of ovarian failure in young girls with Turner syndrome. METHODS: Stored plasma samples obtained at 0 and 12 months were used from 40 adolescents with Turner syndrome who participated in a 12 months randomized controlled trial of the metabolic impact of E2 orally (2 mg/d) vs transdermally (100 µg/d); dose escalation allowed matching of unconjugated E2 levels in the parent study. We measured 12 oestrogen metabolites (total concentrations = conjugated and unconjugated) using a highly sensitive LCMSMS assay. Results from 48 normally menstruating adolescents were used for comparison. RESULTS: After treatment, least square mean (SE) total E2 concentrations were higher in the oral vs transdermal group (6784 pmol/L vs 1123 [1614], P < 0.0001), as was oestrone (E1 ) (91 060 pmol/L vs 19 278 [16 534], P < 0.0001). Also, higher after oral treatment were catechol-oestrogens 4-hydroxy-E2 (149 vs 28 [±49] pmol/L), 2-hydroxy-E2 (300 vs 76 [±52]), 4-hydroxy-E1 (450 vs 105 [±113]), 2-hydroxy-E1 (3094 vs 740 [±684]) and 16α-hydroxy-E1 (3,007 vs 157 [±534]) (<0.001 between groups). Levels were much closer to controls in the transdermal group. CONCLUSIONS: Common feminizing doses of oral oestradiol for 12 months result in substantial accumulation of unphysiologic, genotoxic oestrogens compared to transdermal oestradiol, expanding concerns about oral oestrogens' first hepatic passage. Further studies assessing long-term risks of these metabolites in women taking different forms of oestrogen are needed.

Glutamine and type 1 diabetes mellitus: is there a role in glycemic control?

PURPOSE OF REVIEW: Recent literature suggests dietary glutamine supplementation may lower blood glucose in patients with type 1 diabetes (T1D), who have no residual insulin secretion. The mechanisms and potential relevance to the care of T1D remain unclear. RECENT FINDINGS: Glutamine is involved in multiple pathways including gluconeogenesis, lipolysis, antioxidant defense, the production of nitric oxide, the secretion of peptides (e.g., glucagon-like peptide 1, GLP-1), or neuromediators (e.g., [Latin Small Letter Gamma]-aminobutyric acid), all processes that may impact insulin sensitivity and/or glucose homeostasis. The article reviews potential mechanisms and literature evidence suggesting a role in improving glucose tolerance in patients with illness associated with insulin resistance, as well as the preliminary evidence for the increased incidence of postexercise hypoglycemia in T1D after oral glutamine. SUMMARY: Further studies are warranted to determine whether the lowering effect of glutamine on blood glucose is sustained over time. If so, long-term randomized trials would be warranted to determine whether there is a role for glutamine as an adjunct dietary supplement to improve glucose control in patients with T1D.

Pediatric silent corticotroph pituitary adenoma and role for proton therapy: case report.

Tumors involving the sella are commonly craniopharyngiomas, optic pathway gliomas, or pituitary adenomas. Functioning adenomas are expected, with prolactinomas topping the differential. The authors present the case of a silent corticotroph adenoma, which has not been described in the pediatric population, and they detail the use of proton therapy, which is also novel.

Is There a Difference between Ultrasonographic (US) Uterine Changes of Oral Versus Transdermal (TD) 17ß Estradiol (17ß E2) in Girls with Turner Syndrome (TS)? Own Experience and Literature Review.

BACKGROUND: Among patients with Turner Syndrome (TS), premature ovarian failure is a main feature. Recently published consensus guidelines recommend that transdermal (TD) estradiol is the preferred route for estrogen replacement. Studies related to ultrasound (US) measurements during estrogen replacement in TS patients using estradiol (17ß E2) and correlating uterine growth with estrogen metabolites are limited. OBJECTIVES: To compare uterine morphology and hormonal changes depending on route of administration of 17ß E2 (oral vs. TD) in a small population of girls with TS. SUBJECTS: 11 hypogonadal girls with TS (mean (SE) age 14.5 ± 1.4 years; BMI -0.98 ± -1.0 SDS) who participated in a larger study on the effects of oral versus TD 17ß E2 agreed to do a sub-study on the effect of the form of 17ß E2 treatment on uterine size. METHODS: 17ß E2 was given orally or TD for 12 months, titrated to doses up to 2 mg orally or 100 µg TD to achieve normal estradiol levels. Subjects received monthly progesterone for 1 week for withdrawal bleeding. At baseline, 6 and 12 months, a pelvic ultrasound was performed while on estradiol only. RESULTS: Uterine morphology and endometrial thickness increased comparably in both groups. E2 concentrations were comparable at 12 months between both groups but E1 and E1S were lower in TD group at 12 months. CONCLUSIONS: According to our experience, in a group of TS patients randomized to oral vs TD 17ß E2 and monitored with trans-abdominal US, both groups achieved similar increases in uterine size comparable to normal women. To confirm our observation a larger sample and a longer evaluation period is needed.

Does oral glutamine improve insulin sensitivity in adolescents with type 1 diabetes?

OBJECTIVE: The decline in insulin sensitivity (SI) associated with puberty increases the difficulty of achieving glycemic control in adolescents with type 1 diabetes (T1D). The aim of this study was to determine whether glutamine supplementation affects blood glucose by enhancing SI in adolescents with T1D. METHODS: Thirteen adolescents with T1D (HbA1C 8.2 ± 0.1%) were admitted to perform afternoon exercise (four 15-min treadmill/5-min rest cycles of exercise) on two occasions within a 4-wk period. They were randomized to receive a drink containing either glutamine (0.25 g/kg) or placebo before exercise, at bedtime, and early morning in a double-blind, crossover design. Blood glucose was monitored overnight, and a hyperinsulinemic-euglycemic clamp was performed the following morning. RESULTS: Blood glucose concentration dropped comparably during exercise on both days. However, the total number of nocturnal hypoglycemic events (17 versus 7, P = 0.045) and the cumulative probability of overnight hypoglycemia (50% versus 33%, P = 0.02) were higher on the glutamine day than on the placebo day. During clamp, glucose infusion rate was not affected by glutamine supplementation (7.7 ± 1 mg • kg-1 • min-1 versus 7.0 ± 1; glutamine versus placebo; P = 0.4). CONCLUSIONS: Oral glutamine supplementation decreases blood glucose in adolescents with T1D after exercise. Insulin sensitivity, however, was unaltered during the euglycemic clamp. Although the mechanisms involved remain to be elucidated, studies to explore the potential use of glutamine to improve blood glucose control are needed.

Estrogen therapy in Turner syndrome: does the type, dose and mode of delivery matter?

The best type, dose and route of estrogen replacement in hypogonadal females has not been fully elucidated and is the subject of this brief review. When feminizing girls with different forms of hypogonadism micronized 17betaE2 should be considered the first choice as it is the most physiological and can be accurately measured in plasma. Most studies of the metabolic effects of the different routes have also used different types of estrogen making comparisons difficult. However, when using the same estradiol compound, 17betaE2 transdermal results in E2, E1 and bioestrogen concentrations closer to normal as compared to oral and achieves greater suppression of LH/FSH but similar IGF-I and lipid concentrations. Whether this translates into better body composition and metabolic outcomes in girls with hypogonadism is being actively investigated and data will soon be available.