Endocrine Abstracts

A 45 year old man was referred to endocrinology with increasing weakness, lethargy, loss of libido and erectile dysfunction. Initial investigations showed hypogonadotrophic hypogonadism with testosterone 0.8 nmol/l (8.2–32.2), FSH <1 U/l, LH<1 U/l, SHBG 93 nmol/l and secondary hypothyroidism with TSH 1.65 mU/l, FT3 2.1 pmol/l FT4 9 pmol/l, prolactin 180 mU/l, IGF-1 12.5 nmol/l. Short synACTHen test showed normal adrenal response (692 to 1014 nmol/l) with a higher baseline cortisol than expected. He had ongoing weight loss 61.4 kg (BMI: 18.1 kg/m²) from 67 kg (BMI: 19.8 kg/m²) few months earlier. MRI scan of pituitary gland was normal. The Patient was commenced on Levothyroxine 150 mcg daily and Tostran 2% titrated up to 4 pumps. However, he continued to lose weight (51 kg, BMI:15 kg/m²) and he was hospitalised for extensive investigations. During admission the ward staff noticed very restricted eating. Psychiatric review revealed unusual perfectionist personality with anankastic traits. He attributed a number of symptoms to different foods which he subsequently avoided. He received dietetic input and at discharge he had regained some body mass BMI 16 kg/m². Unfortunately, his weight dropped further down (BMI: 12.6 kg/m²). Endocrine biochemistry was entirely in keeping with that seen in starvation and anorexia nervosa: with hypogonadotrophic hypogonadism (LH 1.0 U/l, FSH 6.5 U/l,) hypercortisolaemia (cortisol 843 nmol/l), low IGF-1 2.8 (13–35. Despite Levothyroxine 150 mcg daily thyroid function shown low FT3 conversion (<2.5 pmol/l), TSH 0.26 mU/l, FT4 14 pmol/l He underwent a percutaneous endoscopic gastrostomy for enteral feeding and his BMI has so far improved to 16.4 kg/m². Follow-up endocrinology investigations 2 months later shown improved gonadotrophins (FSH 14.2 U/l LH 3.5 U/l), testosterone 5.5 nmol/l (tostran has been discontinued 3 months prior). Thyroid function shown TSH 0.61 mU/l, FT3 improved but borderline low (3.4 pmol/l) and FT4 12 nmol/l. He continues to take levothyroxine 125 mcg with the plan to titrate this down and discontinue in the future.

Discussion: The Endocrine consequences of chronic malnutrition seen in eating disorders have been mostly reported in women with anorexia nervosa. Eating disorders rarely affect men, however both genders seem to suffer from many of the same endocrine complications [1] such as: hypercortisolaemia, hypogonadotrophic hypogonadism, secondary hypothyroidism, low IGF-1 secondary to chronic GH resistance seen in starvation. Hypothalamic down-regulation occurs as a protective mechanism aiming to reduce metabolic rate and conserve the resources [2].

References

[1] Miller, ‘Endocrine Effects of Anorexia Nervosa.’

[2] Usdan, Khaodhiar, and Apovian, ‘The Endocrinopathies of Anorexia Nervosa.’