Diabetic Eye Disease
People who have diabetes are at high risk for a number of eye problems that can cause severe vision loss or blindness. The most common dia- betic eye disease is diabetic retinopathy, which is damage to the blood vessels in the retina, the light- sensitive membrane at the back of the eyeball. In some people with diabetic retinopathy, blood ves- sels in the retina may swell and leak ﬂuid. In other people, abnormal new blood vessels grow on the surface of the retina. These changes can produce loss of vision or blindness.
In the early stages of the disease, no pain or other symptoms may be present. This is why, if you have diabetes, you should have your eyes examined at least once a year. During the exami- nation, the doctor will use eyedrops to dilate (enlarge) your pupils so that he or she can see inside your eyes to check for signs of the disease. As diabetic retinopathy progresses, the person may experience blurred vision or vision loss.
Doctors treat diabetic retinopathy by using laser surgery to seal the leaking blood vessels or to shrink abnormal vessels. Diabetic retinopathy can- not be prevented, but you can reduce your risk of developing the disease and slow its onset and pro- gression by keeping your blood glucose level within normal range.
A cataract (see page 390) is a cloudy covering that appears over the normally clear lens of the eye. People with diabetes are twice as likely to develop cataracts as are people without diabetes. Cataracts also develop at an earlier age in people with diabetes. Usually cataracts can be surgically removed.
If you have diabetes, you also have twice the normal risk of developing glaucoma (see page 388). This disease is caused by abnormally high pressure from excess ﬂuid in the eyeball. The increased pressure damages the optic nerve and blood vessels in the eye, resulting in vision loss. Doctors treat glaucoma with medications or laser surgery.
Early detection and treatment, before vision loss occurs, are the best ways to control diabetic eye disease. If you have diabetes, make sure you have a thorough eye examination at least once a year. For more information on diabetic retinopa- thy, cataracts, and glaucoma, see chapter 20.
inhibitor can sometimes help prevent kidney damage, even if your blood pres- sure is normal. It is very important to control your blood pressure to prevent kid- ney damage. Be sure to take your blood pressure medication as prescribed. See your doctor right away if you think you might have a bladder or kidney infection, indicated by cloudy or bloody urine, pain or burning during urination, and fre- quent urination or an urgent need to urinate. Back pain, chills, and fever also are possible symptoms of a kidney infection.
Over time, a high blood glucose level can damage the nerves in your body. Nerve damage due to diabetes can produce a loss of sensation or cause pain and
Foot Care Tips for People with Diabetes
People with diabetes are prone to developing severe infections that are slow to heal. The feet are especially susceptible to infection, even from something as common as an ingrown toenail. Nerve damage produced by diabetes can cause numbness in the feet that reduces the person’s ability to feel pain from an injury or infection. An infection can become so serious that it results in the need for amputation.
Controlling your blood glucose level with diet, exercise, and your daily insulin intake can go a long way toward preventing foot problems. The following tips also can help you take better care of your feet:
• Check your feet every day. Look for cuts, blisters, red spots, and swelling, and use a mirror to check the bottoms of your feet.
• Wash your feet every day. Bathe your feet in warm (not hot) soapy water every day and dry them well, especially between the toes.
• Keep your feet soft and smooth. Apply a moisturizing lotion over the tops and bottoms of your feet but not between your toes.
• Smooth corns and calluses gently. Use a pumice stone to gently rub rough spots away.
• Trim your toenails each week. Cut them straight across and ﬁle the edges gently with an emery board or nail ﬁle.
• Always wear shoes and socks. Never walk barefoot, because you could injure your feet.
Wear shoes that are comfortable and ﬁt well.
• Protect your feet from hot and cold. Wear shoes at the beach or on hot pavement. Wear socks if your feet get cold at night.
• Keep the blood circulating to your feet. Put your feet up when sitting. Wiggle your toes and move your feet up and down for a few minutes two or three times a day. Do not cross your legs for long periods. Do not smoke.
• Be more active. Ask your doctor to help you plan a regular exercise program.
• See your doctor regularly. The doctor will check your feet for any potential problems.
Call your doctor right away if a cut, sore, blister, or bruise on your foot does not begin to heal after a day. Follow your doctor’s advice about routine foot care.
burning in your feet. Nerve damage happens slowly, and you may not realize that you have a problem. Your doctor will routinely check the sensation and the pulse in your feet to look for signs of nerve damage.
A high level of blood glucose also can damage the small blood vessels and nerves in and around the penis. Therefore diabetes can interfere with both the nerve impulses and the blood ﬂow necessary to produce and maintain an erec- tion. About 60 percent of men with diabetes experience erectile dysfunction (see page 146).
Diabetes can cause infection of the gums and the bones that hold your teeth in place. Like any infection, gum disease (see page 409) can cause your blood glu- cose level to rise, making the problem worse. Without treatment, your teeth can become loose and begin to fall out. To help prevent gum disease, see your den- tist twice a year and tell him or her that you have diabetes. And be sure to brush and ﬂoss your teeth twice a day.
Cancer of the Pancreas
Pancreatic cancer is one of the leading cancers in men, with 26,000 new cases diagnosed each year. It is the ﬁfth most common cause of cancer deaths in the United States and around the world. Most pancreatic cancer begins in the ducts that carry pancreatic juices into the ﬁrst section of the small intestine. A rare type of pancreatic cancer begins in the cells inside the pancreas (known as the islets of Langerhans) that produce insulin. As the cancer grows, the tumor invades organs—such as the stomach and the small intestine—that surround the pancreas. Cancer cells also can break away from the main tumor and spread to other parts of the body—most commonly the lymph nodes or the liver—through the bloodstream.
Cancer of the pancreas has been called a “silent” disease because it usually does not cause symptoms in the early stages. The cancer may grow for some time before it causes symptoms. When symptoms occur, they may be so vague that they go unnoticed. For these reasons, cancer of the pancreas is often not detected until the later stages, when the cancer has already spread outside the pancreas.
Symptoms include pressure in the upper abdomen that sometimes spreads to the back. The pressure may worsen after the person eats or lies down. Other symptoms include nausea, loss of appetite, weight loss, and weakness. If the tumor blocks the duct through which bile (a ﬂuid produced by the liver that helps digest fat) passes into the small intestine, the person develops jaundice (yellow- ing of the skin and the whites of the eyes), and his or her urine may become dark.
The cause of cancer of the pancreas is unknown, but certain factors can increase your risk of developing the disease. Age is a risk factor; the disease rarely occurs before age 40, and the average age at diagnosis is 70. Smoking and heavy drinking are also risk factors for cancer of the pancreas. Cigarette smok-
ers develop the disease two to three times more often than nonsmokers. Having diabetes also increases your chances of developing cancer of the pancreas. Peo- ple with diabetes develop the disease about twice as often as the general popula- tion. The risk of developing pancreatic cancer is higher in people who consume a diet that is high in fat and low in fruits and vegetables.
To diagnose cancer of the pancreas, the doctor will perform a physical exam- ination and ask about the person’s health history (see page 82). He or she will order tests that will produce images of the pancreas. Such tests also will help the doctor determine how far the cancer has progressed. Computed tomography (CT) scanning (which uses a series of X rays and a computer to produce cross- sectional images), magnetic resonance imaging (MRI; which uses a powerful magnetic ﬁeld and a computer to produce three-dimensional images), and ultra- sound scanning (which uses high-frequency sound waves to produce images) are commonly used to diagnose cancer of the pancreas. To view the pancreatic ducts, the doctor probably will order a test called endoscopic retrograde cholangiopan- creatography (ERCP). In ERCP, an endoscope (a lighted, ﬂexible viewing tube) is passed down the throat, through the stomach, and into the small intestine. After the endoscope is in place, contrast medium (a type of dye) is injected into the pancreatic ducts, and a series of X-ray images is produced.
Images of the pancreas and nearby organs may not provide adequate informa- tion for the doctor to make a ﬁrm diagnosis of pancreatic cancer. He or she also may have to perform a biopsy, in which a small sample of tissue is taken from the pancreas for analysis under a microscope. A biopsy can be performed in three ways. In a needle biopsy, the doctor inserts a long needle into the abdomen and then into the pancreas to obtain a tissue sample. A brush biopsy is performed at the same time as the ERCP. The doctor inserts a tiny brush into the endoscope and rubs off some cells for later analysis. Sometimes the doctor performs the biopsy during a surgical procedure known as a laparoscopy. During this proce- dure, the doctor inserts a laparoscope (a viewing tube equipped with a precision optical system that sends clear images to a video monitor) into the abdomen through a small incision and removes a small tissue sample. The doctor also can use the same tube to see inside the abdomen to determine the location and the extent of the cancer.
Cancer of the pancreas can be cured only in its early stages. However, because of the lack of early symptoms, the disease is not often detected until it is in its later stages, when treatment is difﬁcult. Therefore, treatment often focuses on improving the person’s quality of life by controlling the symptoms of the dis- ease. Pain relievers are usually prescribed.
Depending on the type of pancreatic cancer, its location, and whether it has spread, the doctor may attempt to remove the tumor or stop its growth by using surgery, radiation therapy, or chemotherapy (treatment with powerful anticancer drugs). Surgery involves removing all or part of the pancreas and possibly
some surrounding tissue. Doctors also use surgery to help relieve symptoms that occur if a duct is blocked. During radiation therapy, the doctor uses a radioactive substance or X rays to damage cancer cells and stop them from growing and spreading. The radiation affects cells only in the treated area. Chemotherapy uses drugs to kill cancer cells. It is given in cycles so the person can have a period of recovery between treatments. Sometimes doctors use surgery, radiation therapy, and chemotherapy in combination to treat cancer of the pancreas. All three forms of treatment have side effects that your doctor will describe for you.
Surgery to treat cancer of the pancreas is major surgery that requires a lengthy recovery period. Pain, fatigue, and weakness are common. Fatigue is also a side effect of radiation therapy, which also can cause hair loss, darkening of the skin, nausea, vomiting, and diarrhea. People undergoing chemotherapy may be more susceptible to infection; may bruise or bleed easily; may have nausea, vomiting, and diarrhea; and may develop sores in the mouth. The side effects vary from person to person.
People living with cancer of the pancreas (and their families) face many prob- lems and an uncertain future. Coping with these problems may be easier when they can share their concerns in a support group and if they have help with home care. Your doctor or a social worker at your local hospital can refer you to appro- priate sources of information and assistance.
Other Endocrine System Disorders
Here are two closely related disorders of the endocrine system that are more common in women but also can occur in men:
• Hyperthyroidism. This condition occurs when an overactive thyroid gland pro- duces excessive amounts of thyroid hormone, increasing your metabolic rate and your heart rate. Graves’ disease (see below) is the most common cause of hyperthyroidism. Early symptoms develop gradually and usually include irritability, anxiety, mood swings, dry skin, weight loss, increased appetite, and increased sweating. In more advanced cases, symptoms can include an enlarged thyroid gland (called a goiter), muscle wasting, tremor, abnormal heart rate and rhythm, and bulging eyeballs. A goiter is visible as a swelling on the neck. A large goiter may press on the esophagus or the trachea, making it difﬁcult or painful to swallow or breathe. Doctors diagnose hyperthyroidism based on the symptoms, a physical examination, and blood levels of thyroid hormone and thyroid-stimulating hormone. Doctors often prescribe beta- blockers (see page 225) to relieve symptoms such as a rapid heart rate. Antithyroid medications (such as methimazole and propylthiouracil) that reduce production of thyroid hormones also are prescribed. If treatment with medication is ineffective, you may be treated with a single dose of radioac- tive iodine (in liquid or pill form), which collects in the thyroid gland, even-tually destroying some thyroid tissue and inhibiting production of thyroid hor- mones. Some people may require additional radioactive iodine treatments. (In some cases, a doctor may treat a person with radioactive iodine before pre- scribing medication.) If a goiter is particularly unsightly or if it is causing problems with swallowing or breathing, a doctor may recommend surgery to remove the enlarged portion of the thyroid gland.
• Graves’ disease. Also called diffuse toxic goiter, Graves’ disease is an autoimmune disease (a disturbance in the body’s immune system) in which the body produces antibodies that attack the cells of the thyroid gland. Because these antibodies imitate thyroid-stimulating hormone, they cause the thyroid gland to produce excessive amounts of thyroid hormone, resulting in a condition known as hyperthyroidism (see above). Graves’ disease tends to run in families. Symptoms, diagnosis, and treatment are the same as for hyperthyroidism.