Diabetes Mellitus
We now turn to the common problems of metabolism that can often be treated, controlled, or prevented in a home setting. Knowledge of sugar diabetes is important, because of its high prevalence. This disease has been recognized from antiquity. Both Greek and Chinese writings have mentioned it; and in the sixteenth century Paracelsus initiated the study of the chemistry of diabetic urine.
The word mellitus, introduced by Thomas Willis one hundred years later, describes the sweetness of the diabetic urine, “as if imbued with honey.” This rapidly led to a dietary approach to this disease, until finally Langerhans, a medical student, in 1869 described the islets in the pancreas where the basic production of insulin occurs.
Two Canadians, Banting and Best, finally prepared the extract from dog pancreas that was capable of reducing the elevated blood glucose level. A fascinating long history of discoveries marks the approaches to understanding and treating this common disorder.
It is estimated that there are about 200 million diabetics in the world and approximately 4.2 million in the United States. This disease is more frequent in older people. Hence, as the population grows and becomes older, diabetes will continue to increase.
With treatment, the life expectancy of the diabetic is increasing, and since inheritance is an important factor, the more diabetics that have children, the greater will be the prevalence of this disease, Obesity is also on the rise and appears to precipitate diabetes among those predisposed to it.
Next to obesity and thyroid disorders, diabetes is the third most common problem in metabolism. Interrelated are the metabolic or hormone, and vascular or long-termed components of this disease. The latter consist of an accelerated arteriosclerosis that leads to premature aging and particularly affects the eyes and the kidneys.
Gangrene of the foot, arteriosclerotic heart disease, blindness, and kidney failure (uremia) are the most frequent manifestations of the vascular syndrome. Statistically, the diabetic is faced, not only with a decreased life expectancy, but also with the eventual possibility of disabling complications.
The early detection of diabetes first involves a high index of suspicion. This disease is two and half times more frequent in relatives of known diabetics. Furthermore, 85% of diabetic patients were or are overweight. Four out of five diabetics are over 45 years of age. Mothers who deliver large babies have a high potential for the development of diabetes.
The simplest screening test for this disorder is a urinalysis for sugar. Measurement of the blood sugar (glucose) level in the fasting patient should also be encouraged as a screening tool. The five-hour Glucose Tolerance Test is less commonly performed for diabetes, but is usually used to diagnose and evaluate hypoglycemia.
Pathologic changes occur with the passage of time in diabetes, and seem accelerated by failure to control this disease. The islets of Langerhans in the pancreas typically deteriorate, resulting in the lack of insulin production. Atherosclerosis occurs earlier in a diabetic patient, often leading to coronary artery disease and stroke as the most frequent cause of death.
These also occur from the lack of insulin production. The eyes show changes after 10 to 1 5 years of diabetes. Small retinal hemorrhages, dilated sacs in the weakened blood vessel (aneurysms), and waxy patches (exudates) develop. Later a dangerous type of new blood vessel forms, then further hemorrhages and gradual or sudden loss of vision.
Although marvelous advances in the diagnosis and treatment of these visual complications have been made, diabetic eye disease remains the second most frequent cause of blindness in the United States. Increased tendencies toward cataract formation also occur.
In the kidney, characteristic damage to the filtering unit (glomerulus) progresses to destroy renal function. Infections of the kidney and urinary tract are common, and many patients go on to develop high blood pressure, serious loss of protein, and later kidney failure.
The symptoms of diabetes, as mentioned above, are multiple. Increased fatigability and weakness is common. The diagnosis is frequently suggested by history of increased thirst (polydipsia), increased urination (polyuria), and excessive hunger (polyphagia) in association with weight loss.
Long standing disease is reflected in the pathologic changes mentioned above. Two typical types of diabetes mellitus are seen. The juvenile onset type is characterized by a rapid onset, with instable diabetes, associated with loss of weight and strength, irritability, and the three “polys” mentioned above.
Insulin therapy is mandatory in this type of patient and long-term medical counseling is needed. The second type of diabetes is termed maturity onset. Frequently symptoms are minimal or absent at first. Weight loss or weight gain may be present. These may be increased tendency to urinary infections or Vaginitis.
Blurred or decreased vision, anemia, loss of sensation, or other neurologic problems may send the patient to the physician. Since many patients are obese, the reduction of weight associated with a careful diet can bring a return of health to most people who will cooperate with simple health principles.
The treatment of diabetes involves several basic principles. Doctors aim to correct the underlying metabolic abnormalities and thereby reduce diabetic symptoms. This is associated first of all by the achieving and maintaining of an ideal body weight.
Our third goal is the prevention or delay of the specific complications associated with diseases of the eye, kidney, and nerves. Finally, we try to stem the accelerating atherosclerosis to which the diabetic is particularly liable. Success in these therapies depends on how well the patient has been instructed and his conscientiousness in following directions.
The avoidance of cigarette smoking, with regular daily exercise, the monitoring of the urine and blood sugar, cholesterol and triglycerides, blood pressure and body weight are all imperative. Basically, however, the treatment of diabetes revolves around an appropriate diet. The dietary treatment must meet the basic nutritional requirements.
These are usually the same as those of a nondiabetic patient and, of course, to be acceptable, taste, variety, economy, and other nutritional factors should be considered. The prevention of high blood sugar occurring after a meal is important to avoid aggravating the symptoms.
On the other hand, if a person is taking insulin it is important to provide enough calories of the right type to prevent hypoglycemic reactions. Ideal body weight should be achieved as soon as possible. In order to delay the atherosclerotic complications, the diet should be low enough in fat and animal products to normalize the serum cholesterol and triglyceride levels.
The basic caloric requirement is dictated by age, ideal weight, physical activity, climate, and the patient’ s occupation. An approximate calculation can be obtained by multiplying the ideal weight in pounds by ten. Individuals who are less active or past middle age should reduce their calories somewhat.
Meals should be regular, usually spaced 5-6 hours apart. They are ideally limited to two or three meals a day, the latter especially for those taking insulin. I recommend taking the greater number of calories at breakfast, in order to provide energy during the active part of the day. Suppers should be light, eaten several hours before going to bed.
Careful regulation of the insulin level can usually avoid the necessity of a bedtime snack. The fat content of the diet should definitely be reduced from the 40% eaten by the average American. Protein should also be reduced slightly. The remaining calories should be obtained from complex carbohydrates.
This can lower the insulin requirement dramatically, and in many maturity onset diabetics, make a need for the needle entirely unnecessary. Some dietary suggestions for diabetics, as used in my institution, are presented in the accompanying tables. Insulin therapy is usually necessary for diabetes of juvenile onset.
Several types are available, having fast, intermediate, and long duration of action. Most of the insulin used in the United States today contains 100 units per milliliter. This has helped considerably to standardize the syringes and simplify the self-administration of this hormone.
Regular or crystalline insulin is the shortest acting and is usually used for emergencies. Its duration of action is 6 to 8 hours. Intermediate acting insulins, such as NPH or Lente have a peak effect in 8-12 hours and usually last for 24. The longer-acting insulins are seldom used.
At times, a second small dose of intermediate insulin before bedtime is preferable to increasing the daily dose. It is preferable to have a small amount of sugar spill in the urine during the day than achieve such rigid glucose control as to render the patient hungry all the time or prone to hypoglycemic reactions.
Be sure to rotate the sites of injections and use sterile techniques in the administration of all insulin hormones. Although many diabetic patients develop antibodies to the insulin used, only a few, about 0.1% will develop insulin resistance. A regular exercise program helps, in combination with the low fat diet, to lower daily insulin requirement.
Using the more convenient but less physiologic oral diabetic pills should be discouraged, because of numerous side effects, particularly an increased acceleration of vascular complications. Hope is definitely on the way for patients with diabetes, who will eat properly, exercise regularly, and keep their weight under control.