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Pediatric Endocrinology 2007

Pediatric Endocrinology 2007. Merrily Poth, M.D. Professor Pediatrics and neuroscience USUHS Bethesda, MD. Pediatric Endocrinology. Purpose of these talks is to review clinical endocrinology, in part in to prepare for pediatric board exams.

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Pediatric Endocrinology 2007

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  1. Pediatric Endocrinology2007 Merrily Poth, M.D. Professor Pediatrics and neuroscience USUHS Bethesda, MD

  2. Pediatric Endocrinology Purpose of these talks is to review clinical endocrinology, in part in to prepare for pediatric board exams. I will emphasize areas targeted in past in board questions. I will also emphasize facts that will help you in your practices, outlining the fundamentals of how to diagnose, when to refer and when to reassure

  3. Caveats • Not completely comprehensive. • Not a substitute for in-depth consultation. • Clinically up-to-date, but not emphasizing newer areas of molecular medicine and genetics.

  4. Principles of Endocrinology • Hormones-chemical compounds secreted into blood stream and transported to distant site-where they react with specific receptors. • Feedback loops-in order to maintain homeostasis, each hormone system has method of sensing need for secretion and altering this up or down.

  5. POSTERIOR PITUITARY CONNECTED TO THE HYPOTHALAMUS BY NERVES SECRETES ANTI-DIURETIC HORMONE AND OXYTOCIN Each hormone is made and secreted in associated with a specific physin.

  6. SECRETION OF VASOPRESSIN IS STIMULATED BY HYPERNATREMIA (HYPEROSMOLARITY) • DECREASED BLOOD PRESSURE/BLOOD VOLUME ALSO STIMULUS, BUT TAKES GREATER DEFICIT

  7. Vasopressin • Binds to vasopressin receptors in renal tubule opening channel to water • In absence of vasopressin cannot concentrate urine • Resultant disease called “diabetes insipidus”

  8. DIABETES INSIPIDUS • PRESENTATION DEPENDS ON AGE OF PATIENT • IN INFANT PRESENTS WITH FTT, LOW GRADE FEVER WITHOUT SOURCE, POOR FEEDING • IN OLDER CHILD PRESENTS WITH POLYURIA AND POLYDYPSIA

  9. PATIENT • 5 YO BOY PRESENTS WITH POLYURIA AND POLYURIA • UP AT NIGHT TO DRINK AND URINATE 3 x PER NIGHT • Sudden onset of symptoms • APPEARS “OBSESSED” WITH WATER

  10. CRITICAL QUESTIONS • WHAT DOES HE DRINK? • WATER VS JUICE- When offered a sweet drink does he prefer water? • Does he wake at night to drink water? SUDDEN VS GRADUAL ONSET

  11. EVAULATION FOR DI • FIRST MORNING VOID SPECIFIC GRAVITY-IF GREATER THAN 1.008 THE DIAGNOSIS IS HIGHLY UNLIKELY • SERUM ELECTROLYTES AND GLUCOSE (Diabetes mellitus is much more common than DI) • IF ALLOWED FREE ACCESS TO WATER WILL MAINTAIN SERUM SODIUM AT HIGH END OF NORMAL

  12. EVALUATION FOR DI (CONT) • WATER RESTRICTION (CAREFULLY) • NPO AFTER MIDNIGHT • WEIGH EVENING BEFORE AND Q 2 HOURS during test • STRICTLY MONITOR URINE OUTPUT AND TEST SPECIFIC GRAVITY OF ALL URINE • IF SPECIFIC GRAVITY INCREASE ABOVE 1008-NEGATIVE DIAGNOSIS

  13. Diagnosis of DI IF WEIGHT LOSS GREATER THAN 5% AND URINE SPEC GRAV DOESN’T RISE, AND URINE OUTPUT CONTINUES AT SAME RATE WITHOUT INTAKE. IF APPEARS NOT TO BE ABLE TO CONCENTRATE URINE NEED TO GIVE DDAVP AND DOCUMENT THAT SPECIFIC GRAVITY OF URINE INCREASES MEASURE SERUM VASOPRESSIN WHEN SODIUM INCREASED-This is most “fool proof measure.

  14. DIABETES INSIPIDUS • IF DIAGNOSIS CONFIRMED AND PT RESPONDS TO EXOGENOUS VASOPRESSIN • NEED TO EVALUATE FOR PITUITARY OR HYPOTHALAMIC PATHOLOGY • IF EVALUATION NEGATIVE REPEAT IN 6 MONTHS • ALSO NEED TO EVALUATE FOR STATUS OF ANTERIOR PITUITARY HORMONES • GH, ACTH, LH, FSH AND TSH

  15. PATIENT • 5 YO BOY PRESENTS WITH POLYURIA AND POLYURIA • UP AT NIGHT TO DRINK AND URINATE 3 x PER NIGHT • Sudden onset of symptoms • APPEARS “OBSESSED” WITH WATER

  16. To diagnose this child as having diabetes insipidus which of the following is true. • A. He must have a elevated serum sodium at baseline. • B. He must awaken at night to drink water. • C. He must be growing normally. • D. His first morning urine can have a specific activity of over 1.010

  17. Review of DI • Cannot concentrate urine. • Will usually drink water sufficient to maintain high normal serum sodium if allowed to. • Treatment is DDAVP, either nasal or oral preparation. • Treated or untreated, the important issue is free access to water, and if not able to drink, replacing output, cc for cc.

  18. ANTERIOR PITUITARY Anterior pituitary is connected to the hypothalamus by blood vessels (the hypothalamic portal system) Releasing factors and other controlling substances travel to pituitary thru this portal system

  19. ANTERIOR PITUITARY • Deficiencies of anterior pituitary hormones can occur singly or in combination • Puberty is a good example of a process that is under control of the hypothalamic-pituitary axis and a good example of active feedback loops.

  20. HYPOTHALAMIC-PITUITARY- GONADAL AXIS

  21. The Hypothalamic-pituitary-gonadal axis GnRH Gonadal steroids LH, FSH

  22. Normal Puberty • Activity of the HPG axis occurs first prenatally, then during the first few months of life, then again at the time of normal puberty. • First event in puberty is pulsing of LHRH by the hypothalamus, which begins to mature the pituitary gland, which then secretes LH and FSH. LOWER RIGHT

  23. PUBERTY in GIRLS • NORMAL PUBERTY BEGINS AT MEAN AGE OF 11 • FIRST SIGN OF PUBERTY-BREASTS IN 85% AND PUBIC HAIR IN 15% • MENARCHE USUALLY APPROX 2 YEARS AFTER THELARCHE

  24. STAGING OF PUBERTY • NEED TO BE COMFORTABLE WITH THE STAGES OF PUBERTY • NEED TO KNOW HOW TO DESCRIBE • NEED TO KNOW WHAT THEY MEAN

  25. Estrogen effects • Breast development Change in body shape and adipose distribution • Growth increase • FUSION OF GROWTH PLATES • Menarche • Psychological changes?

  26. Androgen Effects • Pubic and axillary hair • Growth spurt (?) • Acne • Body odor LOWER RIGHT

  27. NORMAL VARIANTS OF PUBERTY (early signs) • PREMATURE THELARCHE-ONLY SEEN IN GIRLS • PREMATURE ADRENARCHE-MUCH MORE COMMON IN GIRLS

  28. PREMATURE THELARCHE • BREASTS BEGINNING BEFORE AGE OF 3 (OFTEN NOTED “SINCE BIRTH”) • NO OTHER SIGN OF PUBERTY • NOT ASSOCIATED WITH PATHOLOGY AND DOES NOT REQUIRE FURTHER EVALUATION • IN REALITY CAN’T MAKE THE DIAGNOSIS UNTIL YEARS PASS AND PUBERTY HAS NOT PROGRESSED

  29. PREMATURE ADRENARCHE • PUBIC HAIR AFTER THE AGE OF 3 AND BEFORE 8 • No BREAST DEVELOPMENT • NO OTHER SIGNS OF PUBERTY • All labs pre-pubertal except adrenal androgen levels, which are appropriate for physical findings

  30. Precocious Puberty • Much more common in girls. • More likely to be idiopathic in girls. • Cannot predict the time course of pubertal development at the onset.

  31. PRECOCIOUS PUBERTY • FIRST STEP IN EVALUATION IS TO DECIDE WHETHER THIS INVOLVES THE HYPO-THALAMIC-PITUITARY AXIS =CENTRAL PRECOCIOUS PUBERTY • VERSUS-SIGNS OF PUBERTY, WITHOUT ACTIVATION OF THE HP AXIS=INCOMPLETE OR PERIPHERAL PUBERTY

  32. Precocious puberty • If gonadotropins are pubertal then the problem is central. • May be associated with a wide variety of CNS lesions, but most often idiopathic (in girls). • Regardless of the cause, if gonadotropins are elevated it can be treated with a long acting GnRH analogue.

  33. EARLY SIGNS OF PUBERTY COMMON IN GIRLS. • THERE ARE DATA THAT PUBERTY IN GIRLS IS OCCURRING EARLIER NOW. • MAY BE ASSOCIATED WITH OBESITY. • THIS IS ONLY TRUE FOR GIRLS! • NO COMPARABLE DATA FOR BOYS. • MENARCH HAS NOT ADVANCED.

  34. Puberty case 1 • A 6 YEAR OLD AFRICAN AMERICAN GIRL COMES TO YOUR CLINIC FOR A SCHOOL PHYSICAL. YOU NOTICE THAT SHE HAS TANNER II PUBIC HAIR AND A LITTLE BIT OF UNDERARM ODOR.

  35. WHICH OF THE FOLLOWING WOULD YOU FIND REASSURING? • A. AN ADVANCED BONE AGE. • B. CLITOROMEGALLY. • C. FACIAL HAIR. • D. NORMAL GROWTH RATE.

  36. A. AN ADVANCED BONE AGE. • B. CLITOROMEGALLY. • C. FACIAL HAIR. • D. NORMAL GROWTH RATE.

  37. PUBERTY CASE 2 • ANGELA IS A 3 YEAR OLD WHO PRESENTS WITH A 6 MONTH HISTORY OF INCREASING BREAST DEVELOPMENT. • ON EXAM SHE HAS TANNER BREASTS, AND NO PUBIC HAIR (TANNER I)

  38. Angela is a 3 YO who presents with complaint of increasing breast development Noted over past 6 months. No other complaints. This is her growth curve.

  39. What is Angela’s diagnosis? • A. Precocious Adrenarche. • B. Premature Thelarche. • C. Exogenous androgen exposure. • D. Precocious puberty.

  40. PRECOCIOUS PUBERTY • FIRST QUESTION-DOES SHE HAVE “CENTRAL PRECOCIOUS PUBERTY? • PELVIC ULTRASOUND WILL ALLOW YOU TO CHECK SIZE OF HER OVARIES AND SHAPE OF HER UTERUS. • THIS IS “BIOASSAY” FOR GONADOTROPINS.

  41. ANGELA • On pelvic ultrasound her ovaries are noted to be symetrically enlarged and her uterus is also slightly larger than pre-pubertal. • Now what?

  42. CENTRAL PRECOCIOUS PUBERTY • DIAGNOSIS OF CENTRAL PRECOCIOUS PUBERTY REQUIRES EXAMINATION OF CNS TO BE SURE THAT THERE IS NO CENTRAL PROCESS INVOLVED (TUMOR, CYST, HYDROCEPHALUS, ETC) • USUALLY MRI IS PERFORMED.

  43. GnRH analogues • They are long-acting agonists for the GnRH receptor • They act by desensitizing the receptor to endogenous GnRH • Major indications for Rx of central precocious puberty are: • Concerns about eventual short stature • Concerns re the social effects of puberty and menstruation on a young girl and her family

  44. PUBERTY IN BOYS

  45. Normal puberty in boys • Most boys begin puberty between the ages of 9 and 15. The mean age is 12. • The first sign of puberty is testicular enlargement. • This is followed by pubic hair, growth of scrotum and penis, axillary hair, acne, voice changes and finally the growth spurt.

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