Diabetes Mellitus (DM) Past Notes PDF

Diabetes Mellitus  Diabetes Mellitus (DM) Definition: Metabolic disease characterized by increased blood glucose level (hyperglycemia) and decreased glucose tolerance. There is disturbance in carbohydrates, lipid and protein metabolism due to decre...

Diabetes Mellitus  Diabetes Mellitus (DM) Definition: Metabolic disease characterized by increased blood glucose level (hyperglycemia) and decreased glucose tolerance. There is disturbance in carbohydrates, lipid and protein metabolism due to decrease insulin/anti-insulin ratio. Classification of DM: 1) Type I DM (or Insulin dependent diabetes mellitus (IDDM). 2) Type II DM (or Non-insulin dependent diabetes mellitus (NIDDM).  Type I (IDDM) Type II (NIDDM) Incidence: 10% 90% Age: Under 20 years Above 40 years Onset: Rapid Slow Autoimmune or viral disease Defect in insulin secretion or insulin Cause: leads to destruction of the B cells resistance (i.e. receptor or post of the pancreas. receptor defect). Level of blood Low or absent Insulin usually present insulin: Oral hypoglycemic drugs + exercise Treatment: Insulin injection + reduction of weight  Metabolic changes in DM: All the metabolic changes are due to decrease in the insulin / anti-insulin ratio. 1) Changes in carbohydrate metabolism: Decrease glucose uptake, glucose oxidation and glycogenesis. Increase glycogenolysis and gluconeogenesis. This leads to: 1) Hyperglycemia 2) Glucosuria (when blood glucose exceeds renal threshold of glucose which is 180 mg/dl) 3) Polyuria 4) Loss of electrolytes 5) Dehydration 6) Polydipsia (feeling of thirst).  2) Changes in lipid metabolism: Decrease lipogenesis. Increase lipolysis. This leads to: 1) Weight loss 2) Increases free fatty acids in blood 3) Fatty liver 4) Hypercholesterolemia 5) Ketosis 6) Coma.  3) Changes in protein metabolism: Decrease protein synthesis Increase protein catabolism. This leads to: 1) Increased sensitivity to infection 2) delayed healing of wounds  Diagnosis of DM The following laboratory analyses are done for diagnosis and control of DM: 1) Fasting plasma glucose levels: (fasting for 8 hours). 2) 2-hour post-prandial plasma glucose level (2-h PP). 3) Glycated Hb (HbA1c) Non-diabetic healthy subjects will have: - Fasting plasma glucose < 100 mg/dL - 2-h PP < 140 mg/dL  Patients with diabetes mellitus will have: - Fasting plasma glucose > 126 mg/dL - 2-h PP ≥ 200 mg/dL - Random plasma glucose concentration > 200 mg/dL in presence of symptoms. ▪ The diagnosis of diabetes must be confirmed on a subsequent day by measuring FPG, 2-h PP, or random plasma glucose (if symptoms are present). Impaired glucose tolerance (IGT): - An intermediate category between normal and diabetes. - Patients with impaired glucose tolerance may be at increased risk of developing diabetes.  3) Measurement of Glycated Hb (HbA1c): It is considered a good test for follow up of diabetic patients. It is not affected by immediate changes in blood glucose levels (feeding or fasting). Normal level: 4 – 6.5%. >6.5% is diagnostic of diabetes. 8% or more indicates poorly controlled diabetes.  Complications of DM: Most of the complications are due to the damage of the vascular system. They can be divided into: 1) Macrovascular complications (coronary artery disease, stroke and peripheral vascular disease). 2) Microvascular complications (retinopathy, nephropathy and neuropathy).  Types of diabetic coma: Hyperglycemic coma Hypoglycemic coma Usually due to ketosis and acidosis caused Usually due to overdose of insulin Cause by severe uncontrolled DM. or oral hypoglycemic drugs. Respiratory rate Hyperventilation Normal respiratory rate Pulse Weak rapid pulse Strong rapid pulse Skin Dry skin (dehydration) Excessive sweating Excess amounts of Urine Free from glucose or acetone glucose and acetone Intravenous administration of insulin Glucose administration Treatment together with glucose.  Treatment of Diabetes Mellitus 1) Diet control 2) Oral Hypoglycemic Drugs 3) Insulin: Insulin is injected subcutaneously, or by an insulin pen.