Endocrinological Disorders Flashcards
A 14-year-old girl attends the GP with her mother, concerned that her periods have yet to start. On examination, she has normal female genitalia but is noted to have bilateral inguinal hernias. Breast buds and sparse pubic and axillary hair are also present. The girl is a normal weight and IQ for her age.
Androgen insensitivity syndrome
Androgen insensitivity syndrome is an X-linked recessive condition due to end-organ resistance to testosterone causing genotypically male children (46XY) to have a female phenotype. Complete androgen insensitivity syndrome is the new term for testicular feminisation syndrome
- primary amenorrhoea
- undescended testes causing groin swellings = phenotypically female genitalia in a genetic male (bilateral inguinal hernias)
- breast bud development and sparse pubic hair
Diagnosis
- buccal smear or chromosomal analysis to reveal 46XY genotype
- LH high
- Testosterone normal/high
Management
- counselling - raise child as female
- bilateral orchidectomy (increased risk of testicular cancer due to undescended testes)
- oestrogen therapy
Neonatal hypogycaemia threshold
Normal term babies often have hypoglycaemia especially in the first 24 hrs of life but without any sequelae, as they can utilise alternate fuels like ketones and lactate. There is no agreed definition of neonatal hypoglycaemia but a figure of < 2.6 mmol/L is used in many guidelines.
Transient hypoglycaemia in the first hours after birth is common.
Causes of persistent/severe neonatal hypoglycaemia
preterm birth (<37 weeks)
maternal DM
IUGR
hypothermia
neonatal sepsis
inborn errors of metabolism
nesidioblastosis
Beckwith-Wiedemann Syndrome (overgrowth e.g. macrosomia, macroglossia, abdominal wall defects, hypoglycaemia increased risk for childhood tumours)
Symptomatic features of neonatal hypoglycaemia
may be asymptomatic
autonomic (hypoglycaemia → changes in neural sympathetic discharge)
- ‘jitteriness’
- irritable
- tachypnoea
- pallor
neuroglycopenic
- poor feeding/sucking
- weak cry
- drowsy
- hypotonia
- seizures
other features may include
- apnoea
- hypothermia
How do we manage neonatal hypoglycaemia
prevention
- feed baby within 30 mins of birth
- subsequent frequent milk feeding (every 2-3 hrs)
asymptomatic
- encourage normal feeding (breast or bottle) = ask breastfeeding support team to come and support mum and baby with attempting a further feed now, skin-to-skin contact encouraged, support with latching, teach how to hand express or give colostrum via different method, breastfeeding counselling
- monitor blood glucose = before next feed, no more than 3 hours apart
- buccal glucose can be given but must be used in conjunction with a feeding plan and no more than 3 hours between feeds
1.5 - 2.5 mmol/l
- feed immediately
- recheck glucose after 30 minutes → if still low, consider admitting and starting IV glucose
symptomatic or very low blood glucose (<1.5 mmol/l)
- admit to the neonatal unit (NNU)
- Confirm hypoglycaemia with lab blood glucose assay
- IV 10% dextrose 2m/kg bolus
- followed by infusion of 3.6ml.kg/hr of 10% glucose
- Frequently recheck glucose until stable (aim for 3-4 mmol/l)
If hypoglycaemia persistent, refer to endocrinology team for further ix
If hypoglycaemia is 2o to hyperinsulinism, give one of:
- glucagon infusion
- diazoxide + clorthiazide
- somatostatin analogue
Male changes in puberty: what is the first sign
- first sign is testicular growth at around 12 years of age (range = 10-15 years)
- testicular volume > 4 ml indicates onset of puberty
- maximum height spurt at 14
Female changes in puberty: what is the first sign?
- first sign is breast development (threlarche) at around 11.5 years of age (range = 9-13 years)
- height spurt reaches its maximum early in puberty (at 12) , before menarche
- menarche at 13 (11-15)
- there is an increase of only about 4% of height following menarche
Normal changes in puberty
- gynaecomastia may develop in boys
- asymmetrical breast growth may occur in girls
- diffuse enlargement of the thyroid gland may be seen
When to intervene in childhood obesity?
NICE recommend
- consider tailored clinical intervention if BMI at 91st centile or above.
- consider assessing for comorbidities if BMI at 98th centile or above
Associations of obesity in children
- Asian children: four times more likely to be obese than white children
- female children
- taller children: children with obesity are often above the 50th percentile in height
Causes of obesity in children
- growth hormone deficiency (GH does lipolysis so deficiency makes you obese)
- hypothyroidism
- Down’s syndrome (hypothyroidism and T1DM)
- Cushing’s syndrome
- Prader-Willi syndrome
Consequences of obesity in children
- orthopaedic problems: slipped upper femoral epiphyses (SUFE), Blount’s disease (a development abnormality of the tibia resulting in bowing of the legs), musculoskeletal pains
- psychological consequences: poor self-esteem, bullying
- sleep apnoea
- benign intracranial hypertension
- long-term consequences: increased incidence of type 2 diabetes mellitus, hypertension and ischaemic heart disease
Mx of obesity in children:
Primary care, ONLY refer for specialists paeds assessment if complications or endogenous cause suspected
tx only if BMI >98th decile
weight maintenance main goal, BMI reduction achieved as height increases
Lifestyle:
- healthier diet = regular meals, decreased portions, eating together as a family, nutrient-rich foods
- increase physical activity = fun activities, family participation, structured physical activity
- limiting television and other small screen recreational activities to less than 2 hours a day
- counselling
Pharmacotherapy = small subgroup, over 12 y/o with extreme obesity → ORLISTAT`(lipase inhibitor)
Bariatric surgery generally not considered
precocious puberty: definition and two classifications
- ‘development of secondary sexual characteristics before 8 years in females and 9 years in males’
- more common in females
1. Gonadotrophin dependent (‘central’, ‘true’)
- due to premature activation of the hypothalamic-pituitary-gonadal axis
- FSH & LH raised
2. Gonadotrophin independent (‘pseudo’, ‘false’)
- due to excess sex hormones
- FSH & LH low
Precocious puberty in males
Males - uncommon and usually has an organic cause
Testes
- bilateral enlargement = gonadotrophin release from intracranial lesion
- unilateral enlargement = gonadal tumour
- small testes = adrenal cause (tumour or adrenal hyperplasia)
Precocious puberty in females
Females - usually idiopathic or familial and follows normal sequence of puberty
Organic causes
- are rare, associated with rapid onset, neurological symptoms and signs and dissonance
- e.g. McCune Albright syndrome
Mx of precocious puberty in gonadotrophin-dependent precocious puberty
- 90% no identifiable cause
- manage associated brain neoplasms (e.g. optic nerve gliomas)
- GnRH agonist (leuprolide) can suppress puberty via negative feedback
- GH therapy (as GnRH agonists can stunt growth)
- Cryproterone (anti-androgen) is used by specialists
Precocious puberty mx for gonadotrophin-independent
McCune Albright or Testotoxicosis = ketoconazole or cyproterone, GnRH agonist, aromatase inhibitors
CAH = adjustment of hydrocortisone therapy, GnRH agonist
Tumours = specialist referral
