Biochemical Changes in Anorexia Nervosa: Identifying the False Statement
The false statement regarding biochemical changes in anorexia nervosa is that growth hormone level does not change. In fact, growth hormone (GH) levels are typically increased in anorexia nervosa, while the statement about increased cortisol levels is accurate.
Hormonal Alterations in Anorexia Nervosa
Growth Hormone Changes
- Growth hormone levels are typically elevated in anorexia nervosa patients 1, not unchanged as suggested in option (b)
- This elevation occurs alongside a paradoxical growth hormone resistance, resulting in decreased insulin-like growth factor 1 (IGF-1) levels 1
- Research specifically examining GH in anorexia nervosa has confirmed increased levels in both pubertal and post-pubertal patients, with more pronounced elevation in pubertal patients 2
- The elevated GH represents a metabolic adaptation to starvation and energy deficiency 2
Cortisol Changes
- Cortisol levels are indeed increased in anorexia nervosa 3, making statement (a) correct
- Morning plasma cortisol levels are elevated in most anorexia nervosa patients 3
- The hypothalamic-pituitary-adrenal axis shows dysfunction in these patients, including abnormal feedback mechanisms on ACTH secretion 3
- Hypercorticism is a recognized hormonal alteration in anorexia nervosa that can contribute to serious bone conditions like osteoporosis 4
Other Key Biochemical Alterations in Anorexia Nervosa
Metabolic and Endocrine Changes
- Decreased estradiol and progesterone
- Decreased leptin
- Increased ghrelin and adiponectin
- Decreased insulin
- Decreased total and free T3 and free T4
- Decreased IGF-1 despite increased GH (indicating GH resistance) 1
Hematological and Biochemical Abnormalities
- Moderate anemia and leukopenia are common
- Thrombocytopenia occurs less frequently
- Hydroelectrolytic disorders (hypokalemia, hyponatremia, metabolic alkalosis)
- Acute or chronic renal failure
- Elevated transaminases
- Risk of hypoglycemia
- Altered lipid parameters 4
Abnormal GH Response to Stimuli
- Anorexia nervosa patients show paradoxical GH responses to glucose loading, with GH levels increasing rather than decreasing after glucose infusion 5
- They demonstrate lack of GH response to acute administration of dexamethasone, unlike normal subjects 6
- These abnormal responses further confirm the disruption of normal GH regulation in anorexia nervosa
The biochemical profile in anorexia nervosa reflects a complex adaptation to energy deficiency, with hormonal changes that attempt to conserve energy and maintain essential metabolic functions during starvation. Understanding these changes is crucial for proper management and prevention of complications in these patients.