Causative & risk factors
Type 2 diabetes occurs due to a relative deficiency of insulin or due to peripheral insulin resistance. Due to deficiency of beta cells, the pancreas is unable to release adequate levels of insulin to regulate the blood sugar. Also the body cells may develop resistance to the action of insulin. In such a scenario even if the pancreas is able to produce adequate amounts of insulin, the insulin receptors of the body tissues may develop resistance to its action. Thus the body cells cannot use the glucose present in the blood adequately unless the levels of insulin in the blood are increased.
Several risk factors have been identified that predispose to type 2 diabetes. They are:
- Having a first degree relative with diabetes
- Belonging to certain ethnic groups such as Chinese, African or South Asian
- Being middle aged or higher; although diabetes is being diagnosed at younger ages these days
- Being obese
- Leading a sedentary lifestyle devoid of exercise
- History of gestational diabetes
- Diabetes is strongly associated with thyroid disease
- Taking high doses of steroids for long periods can lead to diabetes
Diabetes is labeled as a ‘silent killer’. It is entirely possible to have diabetes for years and yet not notice anything abnormal. The classical symptoms produced by diabetes are polydipsia, polyuria and polyphagia. The person experiences a frequent need to urinate (polyuria). The person may need to have a lot of fluids to keep hydrated (polydipsia).The patient may feel very hungry even after intake of adequate food (polyphagia). This is because even though the person is eating; his cells are not being able to pick up the glucose from the blood. A person with type 2 diabetes may consistently gain weight as a result of overeating. Since the cells are not getting enough glucose, the patient may feel fatigued all the time.
Long-term or uncontrolled diabetes can affect various body systems giving rise to a number of complications such as:
- Diabetic retinopathy – Uncontrolled blood sugar levels affect the small blood vessels of the eye giving rise to several eye conditions such as glaucoma, cataracts and even blindness.
- Diabetic nephropathy – Diabetes can affect the filtering units of the kidney giving rise to albuminuria.
- Diabetic ketoacidosis – The blood becomes acidic and there is accumulation of ketone bodies.
- Heart and circulatory disturbances – People with diabetes are at a higher risk of developing hypertension, stroke, ischemic heart disease and other conditions of the heart or blood vessels.
- Erectile dysfunction – Since diabetes affects the circulation, it can cause erectile dysfunction in men.
- Diabetic foot – Diabetics are prone to suffer from unnoticed foot injuries leading to formation of ulcers or gangrene.
- Infections – Diabetics have a higher susceptibility of catching infections compared to the normal population.
- Poor healing – Cuts, wounds, bruises or other injuries take a longer time to heal in patients with diabetes.
- Hyperosmolar Hyperglycemic Nonketotic Syndrome – This is an emergency condition characterized by very high blood sugar levels in the absence of ketones in the blood or urine.
- Peripheral arterial disease – Characterized by intermittent pain and tingling in the leg
- Diabetic coma
- Additional complications – Diabetic patients are more prone to hearing troubles and gum disease.
- Blood glucose levels – fasting, post-prandial and random levels are tested. Diabetes is suspected if:
- Fasting blood glucose levels, measured after at least 8 hours of fasting are higher than 126 mg/dL. The normal fasting blood sugar levels range from 80-110 mg/dL.
- Random or post-prandial blood glucose levels are higher than 200 mg/dL. Random samples are taken anytime whereas post-prandial samples are taken 2 hours after a main meal. The normal post-prandial blood sugar levels range from 110-140 mg/dL.
- These tests can be easily performed with glucometers at home; however laboratory analysis using plasma yields more accurate results.
- Oral glucose tolerance test – The patient is instructed to fast for 8 hours following which, a measured dose of glucose water is fed to him/her. Blood sugar levels are tested before in the fasting state as well at several timed intervals after the liquid is fed. If the blood glucose levels are higher than the specified levels at the specified intervals on more than 1 occasion, the person is said to have diabetes.
- Glycosylated haemoglobin test (HbA1c) – These levels measure not just the current sugar levels but give an estimate of the average blood sugar levels during the past 1 to 3 months. Non-diabetic people have HbA1c levels of up to 6%. A reading of 6.5% or higher is suggestive of diabetes.
- Plasma fructosamine levels – Similar to HbA1c, this test also gives an estimate of blood sugar levels of the previous 1 to 3 weeks. Since the duration of measurement is shorter, this test gives a quick assessment of blood sugar levels over the past few days.
- Urinary albumin levels – All pre-diabetic and diabetic patients must undergo testing for urinary albumin in order to detect changes of nephropathy.
There is no permanent cure for diabetes. Treating diabetes is a life-long task. The aim of treatment is to stabilize blood sugar levels and prevent or delay complications. The treatment plan includes a combination of lifestyle changes and injectible insulin.
- Lifestyle changes: Lifestyle changes are essential for all diabetics, whether type 1 or type 2. The following changes are recommended:
- Diet – A low-calorie, low-fat diet is advised. Meal timings must be kept consistent. The patient is encouraged to eat smaller portions several times a day, rather than large portions at a time. Any food or drink that causes a sudden spike in the blood sugar levels is to be avoided. Examples of such foods include chips, sweetened drinks, desserts, deep-fried food and confectionaries. These are known as high hypoglycemic index foods. Foods that increase the blood sugar levels steadily and slowly are recommended. Examples include whole grains, fruits, vegetables, low fat dairy etc. These are known as low hypoglycemic index foods.
The American Diabetes Association, recommend that 50% to 60% of daily calories come from carbohydrates, 12% to 20% from protein, and no more than 30% from fat. One can enlist the help of a dietician to plan their meals.
- Exercise – An active lifestyle is recommended for all diabetics since a sedentary life increases the peripheral insulin resistance. Patients are advised to exercise at a moderate intensity 5 times a week.
- Weight management – It is very essential for a person with diabetes to maintain a healthy body weight, recommended for his/her gender, age and height. Obesity increases the peripheral insulin resistance, thus making it difficult to normalize blood sugar levels. Being obese as well as diabetic also puts you at a very high risk of developing heart disease.
- Medications – Medications form the mainstay of treatment in people with type 2 diabetes.
- Various classes of medications are beneficial for patients with diabetes. The physician selects 1 or a combination of these drugs for each patient.
- Sulfonylureas – These drugs stimulate the pancreas to release more insulin.
- Meglitinides – These drugs also stimulate the pancreas to release more insulin, but through a different mechanism.
- Biguanides – These drugs reduce the amount of glucose produced by the liver.
- Sodium-glucose co-transporter 2 (SGLT2) inhibitors – These drugs stimulate the kidney to increase excretion of glucose.
- Thiazolidinediones – These drugs increase the sensitivity of cells to insulin
- Alpha glucosidase inhibitors – These drugs reduce the carbohydrate absorption by the intestine.
- Synthetic amylin – This is an injectible drug. When given with insulin, the effect is much better than that produced by insulin alone.
- DPP-IV inhibitors – These drugs inhibit the enzyme DPP IV from breaking down GLP-1.
- Insulin – When a combination of lifestyle changes and medications fail to stabilize the blood sugar levels, injectible insulin is used. Insulin can be derived from animals (bovine) or human sources. According to how quickly insulin acts, it is classified as rapid-acting, intermediate-acting and long-acting. Insulin is administered subcutaneously, either through pre-filled insulin pens or insulin pump.
Stem cell therapy is being tested in the hope of finding a cure for diabetes.
Bariatic surgery is being considered as a supportive treatment option for obese diabetics.