Read the following article and answer the questions that follow. To check your answers, see the answer key below.
Acromegaly is a rare chronic disease caused by prolonged overproduction of growth hormone (GH) by the pituitary gland. Scientists estimate that, worldwide, three out of every million people develop acromegaly each year and that 40 to 60 out of every million people suffer from the disease at any time. Once recognized, acromegaly is treatable in most patients, but because of its slow progression of symptoms and signs, its diagnosis is often delayed for 15 or 20 years. Untreated, acromegaly can result in serious complications and premature death. It is, therefore, important to recognize the early symptoms of acromegaly and to understand its cause in order to facilitate early diagnosis and treatment.
The name acromegaly is derived from the Greek words for “extremities” and “enlargement” and reflects one of its most common clinical features, the abnormal growth of the extremities and body organs. The onset of the disease is so gradual that neither the patients nor their families notice it. Enlargement of the hands and feet is often an early symptom, with patients noticing changes in ring or shoe sizes. Gradually, facial features become enlarged, especially the frontal bone and mandible. Head size increases because of growth in both soft tissue and skull mass. Ribs thicken, creating “barrel” chests. Overgrowth of bone and cartilage often leads to crippling joint pain from accelerated osteoarthrosis, and as the disease progresses, generalized muscular weakness becomes a serious feature. In addition, other symptoms that may occur are headaches and visual disturbances that could lead to blindness. There may be enlargement of body organs such as the liver, spleen, kidneys and heart. Excess growth hormone also causes changes in sugar and lipid metabolism, which can cause diabetes. The most serious health complications of acromegaly are diabetes mellitus, hypertension, and cardiomyopathy.
In over 90 percent of acromegaly patients, the overproduction of GH is caused by a benign tumor of the pituitary gland called an adenoma. The pituitary is a small gland at the base of the brain, which produces several important hormones that control body functions such as growth and development, reproduction, and metabolism. GH, as the name implies, regulates the physical growth of the body. When tumors compress the pituitary gland, excess growth hormone is produced, resulting in acromegaly. Most pituitary tumors arise spontaneously and are not genetically inherited.
Acromegaly, which occurs with equal frequency in men and women, may occur at any age, but is most frequent in the fourth and fifth decades. Most commonly, it occurs after puberty. When an adenoma of the pituitary gland occurs in childhood, the overproduction of GH results in "gigantism," which is a type of acromegaly. In addition to the excessive growth of extremities and body organs of acromegaly, gigantism is characterized by disproportionately long arms and legs. Because acromegaly occurs more often in adulthood, after the growth plates of the long bones have fused and the patient has stopped growing, the development of excessive GH production does not result in increased height.
In addition to a complete medical history and medical examination, diagnostic procedures for acromegaly include a review of serial photographs taken over the years to observe physical changes in the patient. X-rays may detect bone thickening. If a doctor suspects acromegaly, he or she can measure accurately the GH level in the blood after a patient has fasted overnight. After acromegaly has been confirmed by measuring GH levels, imaging techniques such as computed tomography (CT) scans or magnetic resonance imaging (MRI) scans of the pituitary are used to locate the tumor causing growth hormone overproduction. Both techniques are excellent tools for visualizing a tumor without surgery.
Treatment involves reducing GH production to normal levels and relieving the pressure that the growing pituitary tumor exerts on the surrounding brain areas. It also includes preserving normal pituitary function and ameliorating the symptoms of acromegaly. Currently, treatment options include surgical removal of the tumor, drug therapy, and radiation therapy of the pituitary. Surgery is a rapid and effective treatment. The surgeon reaches the pituitary gland through an incision in the nose and, with special tools, removes the tumor tissue in a procedure called transsphenoidal surgery. This procedure promptly relieves the pressure on the surrounding brain regions and leads to a lowering of GH levels, reversing adverse effects. When surgery is successful and normal daytime GH levels are achieved, a patient's survival is equal to that of the general population. More commonly, hormone levels may improve but not return completely to normal. These patients may require additional treatment, usually with medications that reduce both GH secretion and tumor size. Radiation is usually reserved for patients who have tumor remaining after surgery, for patients who are not good candidates for surgery because of other health problems, and for patients who do not respond adequately to surgery and medication.
1. The thesis statement of this article _______________.
a. gives a definition of acromegaly
b. states the pattern of organization
c. provides statistical information
d. presents six aspects
2. According to the reading, acromegaly is _______________.
a. primarily a disease of the middle-aged
b. a benign tumor of the pituitary gland
c. a treatable inherited disease
d. a complication of diabetes, hypertension, or cardiomyopathy
3. Information about the normal function of GH is given in ___________.
a. paragraph 3, sentence 1
b. paragraph 1, sentence 1
c. paragraph 4, sentence 3
d. paragraph 3, sentence 3
4. The most definitive diagnosis of acromegaly is done through __________.
a. a medical examination
b. MRI scans
c. a blood test for GH levels
d. serial photographs documenting changes in a patient's appearance
5. It is possible to infer that the treatment that currently offers the best hope of recovery for an acromegaly patient is ______________.
a. radiation therapy
b. transsphenoidal surgery
c. drug therapy
d. psychological counseling
6. Based on the reading, the diagnosis of acromegaly is often delayed for 15 or 20 years because ______________.
a. symptoms are mistaken for osteoarthritis
b. the pituitary tumor is too small to be detected
c. changes in the patient are very gradual and not noticeable
d. testing for the disease is very expensive
7. The age group affected by gigantism compared with acromegaly is generally younger.
8. Excessive GH production results in increased height if the growth plates of the long bones have fused.
9. The word ‘features’ (para. 2, line 2 ) means _______________.
10. The word ‘ameliorating’ (para. 6, line 3) means ______________.
11. The word ‘it’ (para. 4, line 3) refers to _________________.
12. The word ‘it’ (para. 6, line 2) refers to __________________.
1. b 2. a 3. d 4. c 5. b 6. c 7. a 8. b 9. d 10. c 11. a 12. d