Many of the estimated 17 million people in the U.S. with diabetes do not know that they have the disease. Symptoms often go unrecognized and the disease remains 'silent' until detected with a blood test or an eye exam. Classic symptoms of diabetes are: increased thirst, urination, hunger, lethargy, and blurred vision.
Blood sugar levels may be high or fluctuate widely due to inadequate insulin that is required to help the body's tissues use sugar for energy. Unstable or high blood sugar may cause changes in an individual's eyeglass prescription due to swelling of the eye's internal lens.
Tests which measure blood sugar (glucose) can help to diagnose diabetes. Fasting blood glucose levels (measured after fasting for at least 8 hours) above 126 are considered abnormal and diagnostic for diabetes. Levels below 100 are normal, and levels between 100 and 126 are referred to as pre-diabetic or impaired fasting glucose. Random glucose tests, taken without necessarily fasting, are abnormal if above 200. Levels between 100 and 200 are considered pre-diabetic. Glucose tolerance tests measure glucose levels after a sugar load and test how well the body is able to process sugar. Levels below 140 two hours after a ingesting a prescribed amount of sugar are normal. HbA1c is an indicator of the stability of blood glucose levels over the most recent weeks to months. Glucose attaches to hemoglobin in the blood (glycosylation) and remains attached for the life of the blood cell (about 120 days). In diabetes, excess glucose in the blood binds to more hemoglobin and this is reflected in a higher HbA1c number. Normal levels are 4-6%. Diabetics should try to keep the HbA1c below 7%.
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Diabetes damages the small blood vessels throughout the body and eventually damages the organs of the body. Recent studies show that PKC beta (protein kinase C beta) overactivation may play an important role in the deterioration of small blood vessels. When the disease affects the retina of the eye it is called diabetic retinopathy. About 40% of those who have been diabetic for 10 years or longer develop some retinopathy. This retinopathy is the result of oxygen starvation and the development of microaneurysms and new fragile blood vessels that leak and bleed.This process may go on for a long time unnoticed by the individual with diabetes. A yearly dilated eye examination, however, can detect these changes. While early detection is important to formulating an appropriate health plan, identifying advanced stages of retinopathy will allow the eye doctor to offer critical laser treatment of the retina to help preserve vision. Diabetes is the biggest cause of new blindness in the U.S. working population today. Studies show that individuals who keep blood glucose levels consistently stable will do better overall in sustaining healthier bodies and eyes.