The diabetic patient should learn to recognize symptoms of low blood sugar (such as confusion, sweats, and palpitations) and high blood sugar (such as, polyuria and polydipsia). When either condition results in hospitalization, vital signs, weight, fluid intake, urine output, and caloric intake are accurately documented. Serum glucose and urine ketone levels are evaluated. Chronic management of DM is also based on periodic measurement of glycosylated hemoglobin levels (HbA1c). Elevated levels of HbA1c suggest poor long-term glucose control. The effects of diabetes on other body systems (such as cerebrovascular, coronary artery, and peripheral vascular) should be regularly assessed. Patients should be evaluated regularly for retinal disease and visual impairment and peripheral and autonomic nervous system abnormalities, e.g., loss of sensation in the feet. The patient is observed for signs and symptoms of diabetic neuropathy, e.g., numbness or pain in the hands and feet, decreased vibratory sense, footdrop, and neurogenic bladder. The urine is checked for microalbumin or overt protein losses, an early indication of nephropathy. The combination of peripheral neuropathy and peripheral arterial disease results in changes in the skin and microvasculature that lead to ulcer formation on the feet and lower legs with poor healing. Approx. 45,000 lower-extremity diabetic amputations are performed in the U.S. each year. Many amputees have a second amputation within five years. Most of these amputations are preventable with regular foot care and examinations. Diabetic patients and their providers should look for changes in sensation to touch and vibration, the integrity of pulses, capillary refill, and the skin. All injuries, cuts, and blisters should be treated promptly. The patient should avoid constricting hose, slippers, shoes, and bed linens or walking barefoot. The patient with ulcerated or insensitive feet is referred to a podiatrist for continuing foot care and is warned that decreased sensation can mask injuries.
Diabetes mellitus has been recorded in all species but is most commonly seen in middle-aged to older, obese, female dogs. A familial predisposition has been suggested. It is possible to identify two types of diabetes, corresponding to the disease in humans, depending on the response to an intravenous glucose tolerance test. Type I is insulin-dependent and comparable to the juvenile onset form of the disease in children in which there is an absolute deficiency of insulin—there is a very low initial blood insulin level and a low response to the injected glucose. This form is seen in a number of dog breeds, particularly the Keeshond, Doberman pinscher, German shepherd dog, Poodle, Golden retriever and Labrador retriever.
Recently, battery-operated insulin pumps have been developed that can be programmed to mimic normal insulin secretion more closely. A person wearing an insulin pump still must monitor blood sugar several times a day and adjust the dosage, and not all diabetic patients are motivated or suited to such vigilance. It is hoped that in the future an implantable or external pump system may be perfected, containing a glucose sensor. In response to data from the sensor the pump will automatically deliver insulin according to changing levels of blood glucose.
Magnetic resonance imaging (MRI) is a test that takes pictures of the body's internal organs and soft tissues without using x-rays. A specially trained technician performs the procedure in an outpatient center or a hospital, and a radiologist—a doctor who specializes in medical imaging—interprets the images. A patient does not need anesthesia, although people with a fear of confined spaces may receive light sedation. An MRI may include an injection of a special dye, called contrast medium. With most MRI machines, the person lies on a table that slides into a tunnel-shaped device that may be open ended or closed at one end. Some MRI machines allow the patient to lie in a more open space. MRIs cannot diagnose diabetes insipidus. Instead, an MRI can show if the patient has problems with his or her hypothalamus or pituitary gland or help the health care provider determine if diabetes insipidus is the possible cause of the patient's symptoms.
Patients with type 1 DM, unless they have had a pancreatic transplant, require insulin to live; intensive therapy with insulin to limit hyperglycemia (“tight control”) is more effective than conventional therapy in preventing the progression of serious microvascular complications such as kidney and retinal diseases. Intensive therapy consists of three or more doses of insulin injected or administered by infusion pump daily, with frequent self-monitoring of blood glucose levels as well as frequent changes in therapy as a result of contacts with health care professionals. Some negative aspects of intensive therapy include a three times more frequent occurrence of severe hypoglycemia, weight gain, and an adverse effect on serum lipid levels, i.e., a rise in total cholesterol, LDL cholesterol, and triglycerides and a fall in HDL cholesterol. Participation in an intensive therapy program requires a motivated patient, but it can dramatically reduce eye, nerve, and renal complications compared to conventional therapy. See: insulin pump for illus.
Constant advances are being made in development of new oral medications for persons with diabetes. In 2003, a drug called Metaglip combining glipizide and metformin was approved in a dingle tablet. Along with diet and exercise, the drug was used as initial therapy for Type 2 diabetes. Another drug approved by the U.S. Food and Drug Administration (FDA) combines metformin and rosiglitazone (Avandia), a medication that increases muscle cells' sensitivity to insulin. It is marketed under the name Avandamet. So many new drugs are under development that it is best to stay in touch with a physician for the latest information; physicians can find the best drug, diet and exercise program to fit an individual patient's need.
Diabetes insipidus and diabetes mellitus—which includes both type 1 and type 2 diabetes—are unrelated, although both conditions cause frequent urination and constant thirst. Diabetes mellitus causes high blood glucose, or blood sugar, resulting from the body's inability to use blood glucose for energy. People with diabetes insipidus have normal blood glucose levels; however, their kidneys cannot balance fluid in the body.
To distinguish DI from other causes of excess urination, blood glucose levels, bicarbonate levels, and calcium levels need to be tested. Measurement of blood electrolytes can reveal a high sodium level (hypernatremia as dehydration develops). Urinalysis demonstrates a dilute urine with a low specific gravity. Urine osmolarity and electrolyte levels are typically low.
Some patients with type 2 DM can control their disease with a calorically restricted diet (for instance 1600 to 1800 cal/day), regular aerobic exercise, and weight loss. Most patients, however, require the addition of some form of oral hypoglycemic drug or insulin. Oral agents to control DM include sulfonylurea drugs (such as glipizide), which increase pancreatic secretion of insulin; biguanides or thiazolidinediones (such as metformin or pioglitazone), which increase cellular sensitivity to insulin; or a-glucosidase inhibitors (such as acarbose), which decrease the absorption of carbohydrates from the gastrointestinal tract. Both types of diabetics also may be prescribed pramlintide (Symlin), a synthetic analog of human amylin, a hormone manufactured in the pancreatic beta cells. It enhances postprandial glucose control by slowing gastric emptying, decreasing postprandial glucagon concentrations, and regulating appetite and food intake; thus pramlintide is helpful for patients who do not achieve optimal glucose control with insulin and/or oral antidiabetic agents. When combinations of these agents fail to normalize blood glucose levels, insulin injections are added. Tight glucose control can reduce the patient’s risk of many of the complications of the disease. See: illustration
Keeping track of the number of calories provided by different foods can become complicated, so patients usually are advised to consult a nutritionist or dietitian. An individualized, easy to manage diet plan can be set up for each patient. Both the American Diabetes Association and the American Dietetic Association recommend diets based on the use of food exchange lists. Each food exchange contains a known amount of calories in the form of protein, fat, or carbohydrate. A patient's diet plan will consist of a certain number of exchanges from each food category (meat or protein, fruits, breads and starches, vegetables, and fats) to be eaten at meal times and as snacks. Patients have flexibility in choosing which foods they eat as long as they stick with the number of exchanges prescribed.
According to the National Institutes of Health, the reported rate of gestational diabetes is between 2% to 10% of pregnancies. Gestational diabetes usually resolves itself after pregnancy. Having gestational diabetes does, however, put mothers at risk for developing type 2 diabetes later in life. Up to 10% of women with gestational diabetes develop type 2 diabetes. It can occur anywhere from a few weeks after delivery to months or years later.