Q. My father died a year ago because of diabetes which completely damaged his kidneys. He was diagnosed with the disease in 2007. He was given medicines for his blood sugar but he took them irregularly.  Is diabetes an inherited disease?  What are the initial symptoms of diabetes? Is it caused by eating or drinking too much sweet foods such as softdrinks, chocolotes or ice cream?

—kareen c@yahoo.com

A. Let me answer your last question first because it deals with a very common misconception among laymen. Diabetes mellitus is not caused by eating too much sugar. The persistently high blood sugar level that characterizes diabetes is the result—and not the cause—of the disease.

Diabetes mellitus is caused either by the failure of the pancreas to produce enough insulin or inability of the cells of the body to respond appropriately to insulin, or both. Insulin is a hormone that allows glucose (sugar) in blood to enter the cells of the body. The cells utilize glucose as their main energy source for their various metabolic activities. In diabetes, glucose is unable to enter the cells thus it builds up in blood while at the same time, the cells literally starve. 

There are two main types of diabetes mellitus, type 1 & type 2, but several other rare types exist including gestational diabetes mellitus that occurs during pregnancy. In gestational diabetes, the metabolic abnormality usually disappears after delivery although women who had this condition are at a higher risk (30 to 60 percent) of developing diabetes later in life.

Type 1 diabetes accounts for about five to 10 percent of all cases of diabetes. It is an autoimmune disease that develops when the body’s defense system (immune system) against infection and other foreign substances turns awry and attacks and destroys the cells in the pancreas that produce insulin. It is still unknown what induces the immune system to attack the cells of the pancreas but genetic and environmental factors (like viruses) probably play a role. Type 1 diabetes usually arises in childhood or early adulthood.

Type 2 diabetes (the type your father evidently had) accounts for about 90 to 95 percent of all cases of diabetes. Initially, people with this type of diabetes produce enough insulin, but for unknown reasons, the cells do not respond appropriately to it. Subsequently, over a period of years, insulin production by the pancreas decreases.

The risk factors for type 2 diabetes include advancing age, obesity, family history of diabetes, previous history of gestational diabetes, and a sedentary lifestyle.

Is type 2 diabetes an inherited disease? What we know is that it has a strong genetic tendency, but the genes that predispose a person to the illness have not been identified yet.

Type 1 & type 2 diabetes have very similar initial symptoms, which include frequent urination, frequent thirst, constant hunger, weight loss, blurred vision, and fatigue.

Diabetes cannot be totally prevented but a person can reduce his/her odds of developing the disease by eliminating the modifiable risk factors associated with it—which simply means maintaining a desirable body weight and exercising regularly.

Diabetes mellitus is not curable yet, but it can be controlled by a combination of diet, exercise, and the appropriate drugs. If diabetes is adequately controlled (i.e., if the blood sugar level is always within normal limits), complications will not develop and the diabetic will enjoy a healthy normal life.

If untreated, diabetes invariably leads to a variety of serious, long-term complications that gradually but progressively damage various organs.

Complications of diabetes include damage to the blood vessels of the extremities that leads to poor healing of wounds; damage to the blood vessels of the heart and brain that eventually lead to heart attack and stroke; damage to the eyes that results in blurring of vision and blindness; injury to the kidneys that ultimately cause kidney failure; nerve damage that results in muscle weakness and reduced sensation: and, impairment of the immune system that leads to susceptibility to infection.

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