The Longevity Hormone Klotho is a New Player in the Interaction of the Growth Hormone/Insulin-Like Growth Factor 1 Axis
Tami Rubinek, PhD, Ido Wolf, MD, Dalit Modan-Moses, MD
Klotho was first discovered as an aging-suppressor gene. Mice that do not express klotho die prematurely with multiple symptoms of aging, several of which are also characteristic of decreased GH/IGF-1 axis activity. Klotho is highly expressed in the brain, the kidney, and parathyroid and pituitary glands, but can also serve as a circulating hormone by its shedding, forming soluble klotho (sKlotho) that can be detected in blood, cerebrospinal fluid and urine. Several lines of evidence suggest an association between klotho levels and activity of the GH/IHG-1 axis: The GH-secreting cells in the anterior pituitary of klotho-deficient mice are hypotrophic; klotho levels are altered in subjects with pathologies of the GH/IGF-1 axis; and accumulating data indicate that klotho is a direct regulator of GH secretion. Thus, klotho seems to be a new player in the intricate regulation of the GH/IGF-1 axis.
Ref: Ped. Endocrinol. Rev. 2016;14(1):9-18
Key words: Klotho, Growth hormone deficiency, IGF-1, Anorexia, Acromegaly
Genetic Mutations, Birth Lengths, Weights and Head Circumferences of Children with IGF-I Receptor Defects. Comparison with other Congenital Defects in the GH/IGF-I axis
Jenna Lee Essakow, MD, Aharon Lauterpacht, MD, Pearl Lilos, BSc, Rivka Kauli, MD, Zvi Laron, MD, PhD(hc)
In recent years more and more genetic defects along the GHRH-GH-IGF-I axis have been reported. Mutations of the IGF-I receptor (R) are a rare abnormality of whom only the heterozygote progenies survive.
To summarize, from the literature, data on birth length, weight and head circumference of neonates with IGF-I-R mutations, and to correlate the data with that of other types of mutations in the GH/IGF-I axis.
Sixty seven neonates from 24 published articles were included and forty seven different mutations of the IGF-I (R) located on chromosome 15 have been identified.
Mean (±SD) birth length (BL), available for 26, (10 M, 16F) neonates with a gestational age of 34-41weeks, was 44.2±4cm; one was premature (30cm at 31 weeks). There was a significant correlation between birth length and gestational age (GA) r=0.71 (p<0.001). Mean birth weight (BW) of 41 neonates (18M, 23F) was 2388±743gr. Two premature neonates weighed 650gr and 950gr respectively. The BW correlated significantly with gestational age, (males: r=0.68; p=0.007, females: r=0.49; p=0.024).
The BMI of 25 neonates ranged from 6 to 13. In 22 records marked microcephaly was ascertained or stated. Nine of 16 mothers were short (133 –148cm), m±SD = 150.5±7.3cm.
Ref: Ped. Endocrinol. Rev. 2016;14(1):19-26
Key words: IGF-I-R mutations, Birth length, Birth weight, Head circumference, Brain size, Congenital IGF-I deficiency, Laron syndrome, hGH-IA gene deletion, Congenital IGHD and congenital MPHD.
Methods for Rating Sexual Development in Girls
Vincenzo De Sanctis, MD, Ihab Zaki Elhakim, MD, Ashraf T Soliman, MD, PhD, FRCP, Heba Elsedfy, MD, Rania Elalaily, MD, Giuseppe Millimaggi, MD
Sexual maturity rating (SMR) is important in population studies and in clinical care. Pubertal staging allows doctors to assess the maturation of adolescents to correlate several pubertal phenomena such as age at menarche, growth spurt and final height, to advise and manage patients appropriately and to have sensitive “sensors” of the effects of environmental exposure on human populations. The commonly used markers of the timing of female puberty are thelarche and menarche. Appearance of the breast bud is the first indicator of puberty onset in 90% of girls. Assessment of thelarche may be performed by a physician with expertise in adolescents or by self-assessment, in which the adolescent identifies her stage of maturation based on Tanner’s photographs/illustrations. The assessment of Tanner stages by professionals provides more reliable information than self-assessment but may involve variations between observers. Tanner self-assessment has been proposed as an alternative in various studies. Some studies have found reasonable agreement between self-assessment and examination by a physician whereas others found discrepancies. Measuring nipple and areola diameters is feasible for sexual maturation staging. Both sizes show a significant increase during pubertal development and after menarche. However, the ratings using nipple/areola method need to be analyzed to establish their degree of concordance with standard techniques and other markers of development to prove their effectiveness for SMR in girls. We report a short review of various methods for SMR during pubertal development in girls.
Ref: Ped. Endocrinol. Rev. 2016;14(1):27-32
Key words: Sexual maturation, Tanner's stages, Self-assessment, Nipple size, Areola size, Adolescents
A Multidisciplinary Approach to Puberty and Fertility in Girls with Turner Syndrome
Johanna Viau Colindres, MD, Krista J Childress, MD, Marni Axelrad, PhD, Laurence B. McCullough, MD, PhD, Yunru Shao, MMSc, CGC, Charles Macias, MD, MPH, Jennifer Loveless, MPH, Sheila K Gunn1, MD, Jennifer Bercaw-Pratt, Reid Sutton, MD, Lefkothea P Karaviti, MD, PhD, Jennifer E Dietrich, MD, MSc
Women with Turner Syndrome (TS) have a variety of medical needs throughout their lives; however, the peripubertal years are particularly challenging. From a medical perspective, the burden of care increases during this time due to growth optimization strategies, frequent health screenings, and puberty induction. Psychologically, girls begin to comprehend the long-term implications of the condition, including their diminished fertility potential. Unfortunately, clear guidelines for how to best approach this stage have not been established. It remains to be determined what is the best age to begin treatment; the best compound, dose, or protocol to induce puberty; how, when or what to discuss regarding fertility and potential fertility preservation options; and how to support them to accept their differences and empower them to take an active role in their care. Given the complexity of this life stage, a multidisciplinary treatment team that includes experts in endocrinology, gynecology, and psychology is optimal.
Ref: Ped. Endocrinol. Rev. 2016;14(1):33-47
Key words: Turner syndrome, Puberty, Hormone replacement therapy, Fertility
Ultrasound Elastography in Pediatric Congenital Hypothyroid Patients
Mehmet Akif Sarıca, MD, Tahir Dalkıran, MD, Mehmet Sait Menzilcioğlu, MD, Mahmut Duymuş, MD, Nursel Yurttutan, MD
Congenital hypothyroidism (CH) is most frequently encountered in newborns as an endocrine disorder characterized by thyroid hormone deficiency, and is one of the most common reasons for preventable mental retardation. This prospective study was designed to detect the pediatric occurrences of CH followed as euthyroid, with no anomalies detected via US on the gray scale, in comparison with a pediatric group with normal levels.
A total of 42 apparently healthy children with no thyroid disorder (Group 1) and 54 euthyroid CH (Group 2) using thyroid hormone were included in this study. Both B-mode gray scale ultrasound (US) and elastography examinations were made using Toshiba Aplio 400 device (Toshiba Medical Systems Corporation, Otawara, Japan), with a 12 MHz linear probe. All the radiological examinations were made by a single radiologic physician with at least 5 years of experience in elastography.
In total, 96 occurrences in the right and left lobes of 192 thyroid gland measurements were included in the research. There were 20 males and 22 females in the healthy group (n=42), and 28 males and 26 females in the CH group (n=54). Although, there were no significant differences in the average age or gender (p=0.563), there were significant differences in the strain index (SI) values in the CH group. The receiver operating characteristics (ROC) curve was done to calculate the cut-off value for diagnosing CH with strain index ratio (SIR); the value of the cut-off was 0.695, with 63.1% sensitivity and 50.9% specificity.
This was the first study about CH in children. Our study found the SIR of CH to be higher than the normal thyroid parenchyma. It showed that in parenchymal related CH, SE should be used. This study should be a guide for new studies that should be done about the different etiological factors of CH.
Ref: Ped. Endocrinol. Rev. 2016;14(1):48-53
Key words: Children, Elastography, Congenital hypothyroidism, Thyroid gland
Meeting Report: Festive Symposium Honoring Lynne L. Levitsky, MD, Boston April 4th, 2016
Madhusmita Misra, MD, MPH
Ref: Ped. Endocrinol. Rev. 2016;14(1):56-72
Meeting Report: 2016 Annual Meeting of the Endocrine Society Boston, MA (April 1-4, 2016) Selected Highlights
Johanna Viau Colindres, MD, Yvonne K Lee, MD, Monica Serrano Gonzalez, MD, Patrick Shepherd, MD
Ref: Ped. Endocrinol. Rev. 2016;14(1):73-86
Key words: Thyroid nodules, Thyroid cancer, Ultrasound, Fine-needle aspiration, Radioactive iodine, Adrenal insufficiency, Mineralocorticoid receptor, Glucocorticoid receptor, Hydrocortisone, Central precocious puberty, Gonadotropin-releasing hormone agonist, delayed puberty, Hypogonadotropic hypogonadism
Letters to the editors - Response to “Thyroid Hemiagenesis from Childhood to Adulthood: Review of Literature and Personal Experience”
by Vincenzo De Sanctis, MD, Ashraf TSoliman, MD, PhD, FRCP, Salvatore DiMaio, MD, Heba Elsedfy, MD, Nada ASoliman, MD, Rania Elalaily, MD, Andrey Bychkov, MD, PhD
Ref: Ped. Endocrinol. Rev. 2016;14(1):54-55
Key words: Thyroid dysgenesis, History of medicine, Thyroidhemiagenesis, Thyroid hypoplasia, Thyroid aplasia