Introduction

• Chronic overgrowth of connective tissue and bone.
• Cause: persistent excessive growth hormone (GH).
• Signs:
  • May be mild glucose intolerance or overt diabetes mellitus because GH diabetogenic.
  • Cardiomyopathy; systolic murmur, gallop.
  • Congestive heart failure; pleural effusion, pulmonary edema.
  • Arthritis.
• Diagnosis: biochemistry, urinalysis, radiography.
• Treatment: mild erythrocytosis with severe insulin resistant diabetes mellitus can be controlled with high insulin dose BID (isophane insulin injection (NPH)).
• Prognosis: survival time 8-30 months. Most die of complications, eg CHF, CRF, neurological signs.

Pathogenesis

Etiology

• Progesterone induced.
  Either Prolonged administration of progestagens → hypertrophy and hyperplasia of pituitary somatotrophs.
  Or Following diestrus: mammary gland → excess GH → circulation and into milk.
  Or Pituitary neoplasia (rarely).
  Some progestagens are diabetogenic independently of GH effects, possibly mediated through their glucocorticoid activity.
• Pituitary neoplasia - large acidophil adenomas.
• Hypothalamic neoplasia.

Pathophysiology

• Growth hormone → insulin-like growth factors synthesized and released from liver → promotion of cartilage, bone, cardiac and skeletal muscle and connective tissue growth.
• Growth hormone also → lipolysis and hyperglycemia.

Diagnosis

Treatment

Outcomes