Diabetes Mellitus Type II

History: Individuals often are asymptomatic and only occasionally report the classic symptoms of diabetes mellitus, including increased urination (polyuria), excessive thirst (polydipsia), and excessive hunger (polyphagia). The individual may complain of frequent skin infections that are slow to heal, itching, blurred vision, tingling, numbness, and pain in the arms and legs. There may be a feeling of general fatigue and drowsiness. Women may experience chronic vaginal infections (vaginitis).

Physical exam: High blood pressure is present in at least half the individuals with type 2 diabetes, and obesity is a very common finding. The feet and lower legs are examined carefully for signs of ulceration, persistent infection, or gout. Blood pressure in the leg may be lower than in the arm (ankle-brachial index) indicating poor circulation to the extremities. A decreased sensation of pain may be detected in the legs and feet consistent with peripheral nerve dysfunction (diabetic neuropathy). An eye exam may reveal changes in the blood vessels, bleeding, and yellow or white patches in the retina (diabetic retinopathy).

Tests: Diagnosis depends primarily on plasma glucose levels, especially an elevated level of fasting plasma glucose (FPG) and the presence of impaired glucose tolerance (IGT). Glucose tolerance testing measures and compares fasting and non-fasting blood glucose levels to evaluate glucose metabolism. The oral glucose tolerance test measures blood glucose at half-hour intervals within 2 hours after drinking a set amount of a glucose solution. Individuals with diabetes show abnormal rises in blood glucose (hyperglycemia) within the 2-hour period.

Urinalysis is performed to measure the amount of glucose excreted in the urine; elevated urine glucose (glycosuria) is a typical abnormal finding in diabetes. The absence of ketosis (abnormally elevated concentration of ketones in the blood) is a primary feature that distinguishes type 2 from type 1 diabetes. A blood chemistry profile is performed to evaluate lipid levels, fluid and electrolyte balance, and to measure serum creatinine, an indicator of kidney function. Periodic testing of the amount of glucose bound to a protein (hemoglobin) in red blood cells (glycosylated hemoglobin or HbA1c) may be used to estimate plasma glucose levels over the preceding 1 to 3 months, and may help the physician recommend changes in diet, exercise, and insulin therapy. However, lack of standardization of assays for HbA1c has discouraged physicians from using it for diagnosis even though it may be used to monitor effectiveness of treatment (Kronenberg).