Classification of Diabetes

        Diabetes refers to a condition in which there is elevated blood sugar. It is a chronic disorder of metabolism where the body is not able to effectively utilize the blood sugar. Diabetes can be classified as follows:

• Type 1 Diabetes (or) Insulin Dependant Diabetes Mellitus (IDDM)
• Type 2 Diabetes (or) Non-insulin Dependant Diabetes Mellitus (NIDDM)
• GDM-Gestational Diabetes Mellitus.
• FCPD-Fibrocalculous Pancreatic Diabetes.

 There are other rare conditions of diabetes associated with genetic syndromes. Drugs and toxic metabolites can also induce secondary diabetes. The other specific types of diabetes are:

• Diabetes due to genetic defect in the beta cell function. E.g., - Maturity Onset Diabetes of youth. (MODY)
• Diabetes due to a genetic defect of insulin action.

 Type 1 Diabetes (IDDM)

     This type of diabetes results from complete destruction of beta cells of the pancreas due to auto immunity which results in the absence of insulin secretion. Such patients need insulin treatment for their survival. On withdrawal of insulin, they end up with high blood sugar finally resulting in diabetic ketoacidosis.

     Type 1 diabetes is generally found in young children, adolescents and adults under the age of 40 years. The onset of symptoms is usually sudden, and the major symptoms observed are:

• Increased thirst and appetite.
• Excessive urination.
• Fever and sudden weight loss.

 In some cases, patients present with keto-acidosis or coma especially during recurrent illness or surgery.

 Causes

 Genetic factors, autoimmune and environmental factors play a role in the causation of this kind of diabetes.

 Type 2 Diabetes (NIDDM)

  This type is very common and is widely known as Non- insulin Dependant Diabetes. It develops in later stages of life. Often patients are overweight, (some may be lean due to loss of weight because of uncontrolled diabetes) and have family history of diabetes. They may respond to diet, exercise and oral hypoglycemic drugs. Their symptoms develop gradually and many have insulin resistance.

 Causes

• Genetic factors (family history).
• Environmental factors such as obesity lack of physical activity, stress and drugs such as steroids.

 Common symptoms

• Excessive thirst, hunger and urination
• Loss of weight
• Tiredness
• Irritability
• Pruritis (itching)- often in the private parts
• Burning feet, tingling or numbness of feet

 Differences between Type 1 and Type 2 Diabetes

Type 1 Diabetes or IDDM	Type 2 Diabetes or NIDDM
• Life long dependency on insulin	Can be treated with diet, exercise and oral drugs
• Usually detected below 20 years of age	Usually detected above 25 years of age.
• Negative family.	history of diabetes About 60% have a positive family history
• Diabetic coma occurs if insulin is stopped	Diabetic coma is rare

Gestational Diabetes (GDM)

GDM is a condition where the diabetes sets in during pregnancy. The assessment for GDM should be undertaken at the first prenatal visit. Women with obesity, previous history of GDM, glycosuria or family history of delivering big babies should undergo a spot random glucose screening. If they are found to have elevated blood sugars during the initial screening, they should undergo a glucose tolerance test. If they are normal, they can be retested between 24 and 28 weeks of their gestation. Patients can be treated with diet control in mild cases and insulin may be needed if the sugars are high. Oral hypoglycemic drugs are contraindicated during pregnancy 5 % of patients may continue to have diabetes after delivery.

Impaired Glucose Tolerance (IGT)

The term IGT refers to a metabolic stage intermediary between normal glucose tolerance and diabetes. IGT is more frequent in obese than in non-obese persons. They may be associated with an increased frequency of hypertension, hyperlipidemia, obesity and fasting hyprinsulinemia. About 3-5 % of the patients with IGT progress to diabetes every year. Those with IGT are advised to be on diet control, exercise and adopt life style changes to prevent diabetes.

Fibrocalculous Pancreatic Diabetes (FCPD)

This is an unique secondary type of diabetes occurring due to pancreatic stones. The whole pancreatic gland is shrunken due to pancreatitis and hence the insulin producing cells are damaged, resulting in diabetes. These patients are usually very lean, malnourished and may present with severe abdominal pain prior to developing diabetes. They usually require insulin to control their diabetes.

Clinical Profile	Type 1 DM (IDDM)	Type 2 DM (NIDDM)	GDM(NIDDM)
Age of onset	<40 yrs	>40 yrs	Women of child Bearing age
Body weight	Non- obese	Usually obese	Variable
Prone to Ketoacidosis	Yes	No	Variable
Treatment	Insulin is Essential	Diet, tablets or insulin	Life-style modification With or without insulin
Symptoms	Acute	Gradual onset or may be asymptomatic	Gradual onset or may Be asymptomatic

Who is to be tested?

• All persons manifesting the signs and symptoms of diabetes as mentioned earlier.
• All obese patients, especially with central obesity, i.e., waist-hip ratio>0.9 in men and >0.8 in women.
• Recurrent infections and non-healing ulcers.
• All women with a bed obstetric history, reseated abortions, history of large babies and foetal anamolies.
• At times of physical or mental stress.
• Persons taking drugs like steroids which may precipitate or induce diabetes.
• Patients with hypertension and hyperlipidaemia.

All persons over 30 years, especially in the presence of family history of diabetes.