Which of the following conditions is caused by excess Growth Hormone?

• A. Ricketts
• B. Cushing's disease
• C. Acromegaly
• D. Addison's disease

Answer: (C)

Excess Growth Hormone in adulthood causes acromegaly. Growth hormone acts directly on tissues and, via IGF-1 produced mainly by the liver, promotes growth. When this hormone is elevated after the growth plates have closed, the long bones can’t lengthen, but soft tissues and bone of the face, hands, and feet thicken over time. This leads to the characteristic features of acromegaly: enlarged hands and feet, prognathism with a protruding jaw, spacing of the teeth, thickened skin, and sometimes enlarged organs. Pituitary adenomas that secrete GH are the common source of this excess. The other conditions listed arise from different hormonal or metabolic problems—rickets from vitamin D deficiency, Cushing’s disease from excess ACTH and cortisol, and Addison’s disease from adrenal cortisol deficiency—so they are not caused by too much Growth Hormone.