Diabetes mellitus 1 Objectives Definition of

Diabetes mellitus 1

Objectives • Definition of Diabetes. • Symptoms of Diabetes. • Types of Diabetes. • Lab diagnosis of Diabetes. 2

What is diabetes? q Diabetes mellitus (DM) is a a heterogeneous group of diseases characterized by high levels of blood glucose resulting from defects in insulin production, insulin action, or both. q The term diabetes mellitus describes a metabolic disorder of multiple aetiology characterized by chronic hyperglycaemia with disturbances of carbohydrate, fat and protein metabolism resulting from defects in insulin secretion, insulin action, or both. q The effects of diabetes mellitus include long–term damage, dysfunction and failure of various organs.

q Diabetes mellitus may be associated with characteristic symptoms such as thirst, polyuria, blurring of vision, and weight loss. q The most severe forms, ketoacidosis or a non–ketotic hyperosmolar state may develop and lead to coma and death, in absence of effective treatment. q It is common, affecting up to 2% of Westem populations, 17% in Saudi Arabia. 4

Diabetes Long-term Effects The long–term effects of diabetes mellitus include progressive development of retinopathy with potential blindness, nephropathy that may lead to renal failure, and/or neuropathy with risk of foot ulcers, amputation, Charcot joints, and sexual dysfunction. People with diabetes are at high risk of cardiovascular disease (CVD). 5

Burden of Diabetes The development of diabetes is projected to reach pandemic proportions over the next 10 -20 years. International Diabetes Federation (IDF) data indicate that by the year 2025, the number of people affected will reach 333 million – 90% of these people will have Type 2 diabetes. In most Western societies, the overall prevalence has reached 46%, and is as high as 10 -12% among 60 -70 -year-old people. 6

-Insulin metabolism is abnormal in diabetes, either because of: • reduced secretion or • to insensitivity to its effects. -Two Main types of Diabetes: • Insulin-dependent (IDDM or type 1 diabetes mellitus, formerly juvenile-onset). • Non-insulin-dependent (NIDDM or type 2 diabetes mellitus, formerly maturity onset). 7

Classification of diabetes mellitus Insulin. Dependent (Type I) Diabetes Malnutrition Related Diabetes Mellitus Secondary Diabetes Non-Insulin. Dependent (Type 2) Diabetes Gestational Diabetes Mellitus Impaired Glucose Tolerance 8

1 - Insulin- Dependent (Type I) Diabetes -Insulin secretion is absent or severely reduced in IDDM as a result of immunological destruction of beta- cells in the islets of Langerhans. -Circulating islet cell antibodies are found in the majority of patients at presentation and infiltration of the islets by T lymphocytes also occurs. 9

1 - Insulin- Dependent (Type I) Diabetes -The environmental event effects, usually a viral infection, particularly with: • Coxsackie B 4 • mumps. -Most cases of IDDM present before 30 years of age. -The clinical presentation is often acute, with polyuria, polydipsia, polyphagia, weight loss and tiredness developing over several days and ketosis may be present. 10

2 -Non-Insulin-Dependent (Type 2) Diabetes -NIDDM has been divided by the World Health Organization (WHO) into two main groups: • Obese • Non-obese 11

2 -Non-Insulin-Dependent (Type 2) Diabetes q Insulin secretion is retained, although it is inadequate to control blood glucose levels. q There is resistance to the effects of insulin in due to reduced insulin receptors q Genetic factors are a more important etiological factor in NIDDM than IDDM. q Identical twins have a near 100% chance and the risk of developing NIDDM is higher than IDDM if a parent has the disease. 12

2 -Non-Insulin-Dependent (Type 2) Diabetes - Not all patients with NIDDM are over weight, there is a clear association with obesity. - Obese patients develop NIDDM either have: • diminished pancreatic reserve. • a secretory defect in the pancreatic beta-cells. 13

2 -Non-Insulin-Dependent (Type 2) Diabetes q Clinical onset is usually in middle age and the prevalence increases with age. q NIDDM is often detected by urine testing during a routine medical examination. q Patients may complain of polyuria and polydipsia, ketosis is rare. 14

3 - Malnutrition-Related Diabetes Mellitus q Found mainly in developing countries due to proteindeficient diet. q. The etiology of these is not clear. 16

4 - Diabetes Associated with Other Disorders (Secondary Diabetes) - Diabetes may occur in association with other conditions, particularly pancreatic disorders such as: • chronic pancreatitis • haemochromatosis may cause destruction of beta-cells. 17

4 - Diabetes Associated with Other Disorders (Secondary Diabetes) -Endocrinopathies (endocrine disorders) which result in: - increased secretion of counter-regulatory hormones can induce insulin resistance. -Diabetes occurs in association with several genetic disorders, including: • Turner's syndrome • Down's syndrome 18

5 - Gestational Diabetes Mellitus - Gestational diabetes occurs for the first time in pregnancy. - Glycosuria is common because the renal threshold for glucose is exceeded. - Complications can occur due to blood glucose concentrations in both mother and fetus. - Glucose tolerance reverts to normal after delivery in most cases many later develop frank diabetes. 19

6 - Impaired Glucose Tolerance -Impaired glucose tolerance (IGT) is an asymptomatic condition -Diagnosed on the basis of the response of blood glucose to the ingestion of a standard oral glucose solution (oral glucose tolerance test, OGTT; 75 g anhydrous sugar in 300 ml water, blood and urine samples taken at 2 h). 20

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Lab diagnosis * Glucose : 80 -120 mg/dl [normal ranges] Fasting and 2 h-postprandial. * Hemoglobin A 1 c Reflects weighted average of blood glucose concentration over the preceding 2 -3 months [how high blood glucose is, and how long it has been elevated]. * Others: - Fructosamine, glycated albumin. – C-peptide, insulin. – Microalbumin. 22

Management of DM The major components of the treatment of diabetes are: A • Diet and Exercise B • Oral hypoglycaemic therapy C • Insulin Therapy