Causes of Diabetes

Type 1 Diabetics don’t produce insulin. They need insulin for survival; without insulin, they develop diabetic ketoacidosis (a severe medical emergency). Insulin is secreted by Beta cells in the pancreas. In Type 1 Diabetes, these Beta cells are destroyed by antibodies: islet cells and Glutamic acid decarboxylase (GAD) antibodies.

Type 1 Diabetics are typically thin, <30 years old but can occur at any age. The onset is usually abrupt with nausea, vomiting, weight loss, thirst, excess urination, and even diabetic ketoacidosis.

Type 2 Diabetes usually presents after 30 but is increasingly seen at a younger age.  In Type 2 diabetes, insulin resistance (insulin is not as effective) and later a relative lack of insulin. These people are usually overweight or obese. Symptoms occur gradually. Treatment is with a combination of diet, exercise, and weight loss, with or without oral diabetic pills. Some individuals with Type 2 diabetes may need insulin for good control. Very occasionally, ketoacidosis can occur under severe stress in Type 2 diabetes.

Type 2 Diabetes accounts for about 90 to 95% of all diagnosed cases of diabetes. About 90% of the people with Type 2 Diabetes have a positive family history of this condition. The chance of developing Type 2 Diabetes doubles for every 20% increase in body weight in a genetically susceptible individual.

Gestational Diabetes occurs during pregnancy due to severe insulin resistance (insulin not very effective), caused by hormones that antagonize or block the effect of insulin. The elevated blood sugar resolves after childbirth. Gestational diabetes is glucose intolerance that is first detected during pregnancy. Around 4% of pregnant women develop this. It usually occurs during the second or third trimester. It is more common in obese older women, and typically there is a family history of diabetes. Also, certain ethnic groups are more susceptible. If untreated, there is an increased risk of a big baby, premature labor, and premature pregnancy consequences. Pregnant women should be screened with a 50-mg one-hour glucose tolerance test during the 24^th to 28^th week of pregnancy. High-risk individuals should undergo the glucose screening test much earlier. Approximately 95% of women with gestational diabetes have normal glucose levels after delivery. Some women continue to have high blood sugar and develop Type 2 Diabetes or impaired glucose tolerance.

Diabetes due to malnutrition or Tropical Diabetes occurs mainly in developing countries. Insulin therapy is usually required in this situation.

Diabetes can occur secondary to a pancreatic disease that damages the Beta cells, as in pancreatectomy, hemochromatosis, cystic fibrosis, chronic pancreatitis. These people require insulin for management.

Diabetes is secondary to endocrine conditions where excess hormones antagonize or block insulin, such as in Cushing’s syndrome, acromegaly, pheochromocytoma, primary aldosteronism glucagonoma. These are rare.

Drugs causing hyperglycemia include Dyazide, Beta-Blockers, Glucocorticoids, Estrogen-containing preparations, Nicotinic acid, some medications used in HIV, Pentamidine, psychoactive drugs.

Rare genetic syndromes are associated with diabetes, such as lipodystrophic syndrome, muscular dystrophies, Huntington’s chorea.

Maturity-onset diabetes of the young (MODY) is an autosomal dominant condition (passed on from one generation to the next) with diabetes at a very young age. It should be differentiated from Type 1 Diabetes. A blood test is available to confirm MODY.

The newsletter is only sent if there are any new blogs or articles added.