Type 2 diabetes is primarily due to lifestyle factors and genetics. A number of lifestyle factors are known to be important to the development of type 2 diabetes, including obesity (defined by a body mass index of greater than 30), lack of physical activity, poor diet, stress, and urbanization. Excess body fat is associated with 30% of cases in those of Chinese and Japanese descent, 60–80% of cases in those of European and African descent, and 100% of Pima Indians and Pacific Islanders. Even those who are not obese often have a high waist–hip ratio.
FASTING GLUCOSE TEST. Blood is drawn from a vein in the patient's arm after a period at least eight hours when the patient has not eaten, usually in the morning before breakfast. The red blood cells are separated from the sample and the amount of glucose is measured in the remaining plasma. A plasma level of 7.8 mmol/L (200 mg/L) or greater can indicate diabetes. The fasting glucose test is usually repeated on another day to confirm the results.
The main effector organ for fluid homeostasis is the kidney. ADH acts by increasing water permeability in the collecting ducts and distal convoluted tubules; specifically, it acts on proteins called aquaporins and more specifically aquaporin 2 in the following cascade. When released, ADH binds to V2 G-protein coupled receptors within the distal convoluted tubules, increasing cyclic AMP, which couples with protein kinase A, stimulating translocation of the aquaporin 2 channel stored in the cytoplasm of the distal convoluted tubules and collecting ducts into the apical membrane. These transcribed channels allow water into the collecting duct cells. The increase in permeability allows for reabsorption of water into the bloodstream, thus concentrating the urine.
The typical symptoms of diabetes mellitus are the three “polys:” polyuria, polydipsia, and polyphagia. Because of insulin deficiency, the assimilation and storage of glucose in muscle adipose tissues, and the liver is greatly diminished. This produces an accumulation of glucose in the blood and creates an increase in its osmolarity. In response to this increased osmotic pressure there is depletion of intracellular water and osmotic diuresis. The water loss creates intense thirst and increased urination. The increased appetite (polyphagia) is not as clearly understood. It may be the result of the body's effort to increase its supply of energy foods even though eating more carbohydrates in the absence of sufficient insulin does not meet the energy needs of the cells.
No matter where you are with type 2 diabetes, there are some things you should know. It's the most common form of diabetes. Type 2 means that your body doesn't use insulin properly. And while some people can control their blood sugar levels with healthy eating and exercise, others may need medication or insulin to manage it. Regardless, you have everything you need to fight it.
5. Signs and symptoms ofhyperglycemiaandhypoglycemia, and measures to take when they occur. (See accompanying table.) It is important for patients to become familiar with specific signs that are unique to themselves. Each person responds differently and may exhibit symptoms different from those experienced by others. It should be noted that the signs and symptoms may vary even within one individual. Thus it is vital that the person understand all reactions that could occur. When there is doubt, a simple blood glucose reading will determine the actions that should be taken.
Neuropathy — This is another term for nerve damage. The most common type is peripheral neuropathy, which affects nerves in the feet and hands. The nerves to the legs are damaged first, causing pain and numbness in the feet. This can advance to cause symptoms in the legs and hands. Damage to the nerves that control digestion, sexual function, and urination can also occur.
Home blood glucose self-monitoring is indispensable in helping patients to adjust daily insulin doses according to test results and to achieve optimal long-term control of diabetes. Insulin or other hypoglycemic agents are administered as prescribed, and their action and use explained to the patient. With help from a dietitian, a diet is planned based on the recommended amount of calories, protein, carbohydrates, and fats. The amount of carbohydrates consumed is a dietary key to managing glycemic control in diabetes. For most men, 60 to 75 carbohydrate g per meal are a reasonable intake; for most women, 45 to 60 g are appropriate. Saturated fats should be limited to less than 7% of total caloric intake, and trans-fatty acids (unsaturated fats with hydrogen added) minimized. A steady, consistent level of daily exercise is prescribed, and participation in a supervised exercise program is recommended.
Although age of onset and length of the disease process are related to the frequency with which vascular, renal, and neurologic complications develop, there are some patients who remain relatively free of sequelae even into the later years of their lives. Because diabetes mellitus is not a single disease but rather a complex constellation of syndromes, each patient has a unique response to the disease process.