Diabetes Mellitus


Every cell in the human body needs energy in order to function. The body’s primary energy source is glucose; glucose from the digested food circulates in the blood as a ready energy source for any cells that need it. Insulin is a hormone produced by cells in the pancreas, an organ located behind the stomach.

Diabetes mellitus, commonly referred to as diabetes is a metabolic disorder characterized by high blood sugar levels that result from defects in insulin secretion or action or both. It is a chronic disorder that causes serious health complications such as kidney failure, heart disease, stroke and blindness.

Types of diabetes

There are 3 types of diabetes:

  • Type 1 diabetes: Type 1 diabetes is also called as insulin-dependent diabetes mellitus (IDDM). Type 1 diabetes is diagnosed in 5-10% of populations. Type 1 diabetes is caused when the body stops producing insulin or produces too little insulin to regulate blood glucose level. The body’s defense mechanism, immune system produce antibodies against insulin secreting cells in pancreas and destroy them
  • Type 2 diabetes: Type 2 diabetes is called as non-insulin dependent diabetes mellitus (NIDDM) and accounts for 90-95% of diagnosed diabetes. In type 2 diabetes the pancreas secretes enough insulin, but the body is partially or completely unable to use the insulin. The body develops resistance because of various factors including secretion more and more insulin
  • Gestational diabetes: It is a form of diabetes that occurs during the second half of pregnancy and blood glucose levels return to normal after delivering the baby. Women who develop gestational diabetes may develop type 2 diabetes in future

Pre-diabetes: It is a condition in which the blood sugar level is higher than normal but not high enough to be considered diabetic. The condition carries a high risk of type 2 diabetes as well as heart disease or stroke.


Causes of diabetes

Type 1 diabetes is caused due to an autoimmune disorder. Other causes include injury to the pancreas from disease, alcohol, trauma and surgery. Other causes including environmental factors, viral infection or nutritional factor in childhood may also contribute

Type 2 diabetes is associated with older age, overweight (obesity), physical inactivity, family history of diabetes and previous history of gestational diabetes

Other risk factors for developing type 2 diabetes include obesity, high blood pressure, sedentary life style, high alcohol intake, older age, high fat diet and pregnancy (gestational diabetes)

Symptoms of diabetes

  • Unexplained weight loss occurs due to loss of excessive calories in the urine
  • Polydypsia: As the kidneys produces excessive urine, it causes abnormal thirst, a condition called polydypsia
  • Polyuria: When the blood sugar level rises, the body tries to get rid of extra sugar in the blood by excreting it in the urine. The kidney excretes additional water to dilute the large amount of sugar
  • Delayed wound healing: White blood cells defend the body against bacteria. High blood sugar level prevents these cells from functioning normally and the wounds take much longer time to heal
  • Infections: Infections result from suppression of the immune system and by presence of glucose in the tissues which allow bacterial growth
  • Altered mental status: Irritation, inattention, and extreme lethargy or confusion are the signs of very high blood sugar
  • Dehydration: Excessive urination leads to dehydration as the sugar and large amount of water is excreted out of the body
  • Other symptoms include blurred vision, nausea, vomiting, and fatigue


  • Acute complications: Acute complications include the complications that occur quickly and usually last for a short time
    • Hypoglycemia: It is a condition characterized by an abnormally low level of glucose in the blood
    • Hyperglycemia: It is a condition of abnormally high level of glucose in the blood
    • Diabetic ketoacidosis: It is a condition resulting from a lack of sufficient insulin in the body, causing high blood glucose levels and ketone formation
  • Chronic complications: These include the complications that last long and are recurring
    • Eye complications: Diabetic retinopathy is the chronic complication of diabetes. Diabetes damages the tiny blood vessels inside the retina leading to diabetic retinopathy. It causes temporary or permanent loss of vision. It also increases the risk of developing cataracts and glaucoma
    • Kidney damage: High blood sugar level can damage the kidneys. When kidneys are damaged, wastes and fluids build up in the blood and are not excreted from your body causing diabetic nephropathy and leading to progressive renal failure
    • Nerve damage: Prolonged exposure to high blood glucose and longer duration of diabetes may cause nerve damage leading to diabetic neuropathy
    • Nerve damage can cause complete loss of sensation in the feet. Because of this minor foot injuries can lead to ulcers and infections and even gangrene. Diabetic foot is a term used for foot problems in patients with diabetes
    • Early coronary artery disease: High sugar levels causes narrowing of both the small and large blood vessels of the heart leading to coronary artery disease
    • Increased risk of infection: Bacterial and fungal infections develop when the blood sugar levels are high and the white cells cannot effectively fight infections


Your physician may diagnose the condition by performing various tests, which may include:

  • Fasting blood glucose test – It is often the preferred test done to diagnose prediabetes and diabetes. A single sample of blood is drawn after the person has fasted overnight. Fasting plasma glucose levels of more than 126 mg/dL on two or more occasions indicates diabetes
  • Random blood glucose test – A blood sample can be taken at any time of day. The blood glucose level of 200 mg/dL or higher indicates diabetes
  • Oral glucose tolerance test – It is commonly used for diagnosing gestational diabetes and in conditions of pre-diabetes. The test takes up to 3 hours, and in this test the person fasts overnight and then first sample of blood taken to determine fasting blood sugar level. After this test the person receives a large standard amount of glucose (75 to 100 grams) and blood samples are taken at every 30 to 60 minutes to measure the blood glucose. A person is said to have a normal response if fasting blood sugar level is less than 95 mg/dL, a 1 hour glucose level of less than 180 mg/dL, a 2 hour glucose level of less than 155 mg/dL, a 3 hour glucose level of less than 14o mg/dL
  • HbA1c test – It is a test used to measure the amount of glycated hemoglobin in the blood. Hemoglobin A 1c (HbA1c) is a minor component of hemoglobin. The blood sample is collected from the vein and the puncture site is covered with bandage to stop any bleeding. The normal level of HbA1c is 6 % or less and above 6.5 % may be considered as a condition of diabetes.


Treatment of diabetes involves diet, exercise, medications and other health habits. These will help to improve the blood sugar levels and prevent or minimize the complications of diabetes.

The goal of the treatment is to keep the blood sugar levels within normal range.

Diet – Eat a consistent well balanced diet that is high in fiber and low in saturated fat. Diabetic patients should not eat much sweet food. Meals should be taken on a regular schedule and long periods between meals should be avoided.

Exercise – Regular exercise in any form can also help people control their weight and maintain blood sugar levels within normal range. It can also reduce the risk of developing complications of diabetes.

Smoking and alcohol use – People with diabetes should stop smoking and consume only moderate or eliminate the consumption of alcohol.

Medical treatment – it depends on the type of diabetes, whether the patient has other medical problems, complications of diabetes, age and general health of patient.

Type 1 diabetes involves the daily injection of insulin, usually combination of short acting insulin and longer acting insulin. It is given in two or three injections per day generally around meal times.

Treatment for type 2 diabetes initially involves weight reduction, diabetic diet and appropriate amounts of exercise. If these measures fail, the oral medications are used. If oral medications do not help to control blood sugar level, insulin injections may be required. Your doctor may recommend taking a combination of oral medication and insulin injections to control blood sugar levels.

Anti diabetic agents used for treatment of insulin dependent and non insulin dependent diabetes mellitus include: Insulin detemir (Levemir),Insulin lispro (Humalog), Regular insulin (Humulin R, Novolin R) ,Insulin NPH(Humulin N, Novolin N), Insulin aspart( Novolog),Insulin glargine (Lantus),and Insulin glulisine (Apidra).

Oral Anti hyperglycemic Drugs: These drugs can often lower blood sugar levels and are usually prescribed for people with type 2 diabetes if diet and exercise fail to lower the blood sugar levels. Oral anti hyperglycemic drugs include Sulfonylureas (glyburide) and meglitinides (repaglinide) stimulate the pancreas to produce more insulin. Glyburide is an oral glucose lowering drug of the sulfonylurea’s group. It lowers the blood glucose by stimulating the release of insulin from the pancreas. Repaglinide improves the glycemic control in type 2 diabetes. Biguanides (metformin) and thaizolidinediones (rosiglitazone) do not affect the release of insulin but increase the body’s response to it. Both the drugs are used as adjunct to diet and exercise to improve glycemic control. Glucosidase inhibitors (acarbose), another class of drug, work by delaying absorption of glucose in the intestine.

Preventive tips

  • Keep your weight under control
  • Practice regular exercise
  • Reduce alcohol intake
  • Quit smoking
  • Adherence to medication and treatment of underlying complications or other disease conditions
  • Lifestyle modification
  • Skin care to prevent infections
  • Brush and floss the teeth regularly

Self care at home

The blood sugar level can be checked at home by pricking a fingertip with a lancing device and applying the blood to a glucose meter. The meter reads the value and the test results help patients to make adjustments in their diet, exercise and medications.