Community Medicine Lecture 3: Diabetes PDF

Level (3) - Semester (6) COMMUNITY MEDICINE LECTURE 3 DIABETES DR STRANGE  Diabetes Mellitus (DM) D EFINITION OF D IABETES M ELLITUS (DM)  A group of metabolic diseases characterized by hyperglycemia resulting from defects in insulin secretion, insulin action, or both. D...

Level (3) - Semester (6) COMMUNITY MEDICINE LECTURE 3 DIABETES DR STRANGE  Diabetes Mellitus (DM) D EFINITION OF D IABETES M ELLITUS (DM)  A group of metabolic diseases characterized by hyperglycemia resulting from defects in insulin secretion, insulin action, or both. D EFINITION OF P REDIABETES  A serious health condition where blood sugar levels are higher than normal, but not high enough yet to be diagnosed as type 2 diabetes.  People who have impaired fasting glucose (IFG) and/or impaired glucose tolerance (IGT). Impaired fasting glucose (IFG) Impaired glucose tolerance (IGT) Elevated fasting blood sugar level (110-125 mg/dL) Elevated blood sugar level (140-199 mg/dL) after an overnight fast, after a 2-hour glucose tolerance test, but is not high enough to be classified as DM. but is not high enough to be classified as DM. ❶ - One of the five leading causes of death in many countries. ❷ - Associated with Premature mortality & High morbidity. ❸ - Has high economic & social cost. ❹ - Its incidence and complications can be decreased by lifestyle & pharmacological interventions. - International Diabetes Federation (IDF) has identified Egypt as the 9th leading country in world ❺ for number of patients with Type 2 DM. Dr. Strange Page 1  Community - Horus Semester 6 – Lecture 3 🅰 Type 1 DM 🅱 Type 2 DM Insulin deficiency Insulin resistance Etiology D.2 Destruction of β-cells (insulin producing) ⇓ of Langerhans in pancreas Progressive insulin secretory defect Accounts for ▪ Only 5-10% of those with diabetes. ▪ ∼90-95% of those with diabetes. ▪ Insulin-dependent diabetes ▪ Non–insulin-dependent diabetes Synonyms ▪ Type 1 diabetes ▪ Type 2 diabetes ▪ Juvenile-onset diabetes ▪ Adult-onset diabetes ▪ Patients need to take insulin everyday to ▪ Patients do not need insulin treatment Insulin stay alive. to survive. 🅲 Gestational diabetes:  Diabetes diagnosed in 2nd or 3rd trimester of pregnancy & may improve after delivery. 🅳 Specific types of diabetes due to other causes: ① Genetic abnormalities ② Diseases of exocrine pancreas e.g., cystic fibrosis. ③ Drug-or chemical-induced diabetes e.g., glucocorticoids – Diuretics – β-blockers. ④ Endocrinal disease e.g., acromegaly, Cushing syndrome. Classical symptoms of DM: Polyuria Polydipsia Polyphagia Diagnosis of DM. (WHO Diabetes criteria): Fasting glucose mmol/L (mg/dL) 2-hour glucose mmol/L (mg/dL) Normal < 6.1 (< 110) < 7.8 (< 140) Impaired fasting glucose (IFG) ≥ 6.1 (≥ 110) & < 7 (< 126) < 7.8 (< 140) Impaired glucose tolerance (IGT) < 7 (< 126) ≥ 7.8 (≥ 140) DM ≥ 7 (≥ 126) ≥ 11.1 (≥ 200) Glycated hemoglobin (hemoglobin A1c) ≥ 6.5 is recommended by American Diabetes Association in 2010; it has yet to be adopted by WHO. Dr. Strange Page 2  Community - Horus Semester 6 – Lecture 3 Type 1 DM Type 2 DM ▪ Absolute insulin deficiency. ▪ Interaction between: ① Genetic predisposition. Caused by ② Lifestyle. ③ Environmental factors. ▪ 10% of all cases of DM. ▪ 90% of all cases of DM. Account for ▪ Affecting nearly 20 million people worldwide. ▪ Majority of cases are diagnosed either: ▪ ⇈ with age & most cases diagnosed Affect o At age of 4-5 years. after age of 40 years. o In their teens & early adulthood. ▪ ⇈ world-wide. ▪ ⇈ rapidly. Incidence ▪ Annual ⇈ in incidence in children < 15 ▪ Number of adults with DM will ⇈ to years old is about 3.4%. 370 million by 2030 (WHO). Dr. Strange Page 3  Community - Horus Semester 6 – Lecture 3 Type 1 DM Type 2 DM 🅰 Genetic factors 🅰 Genetic factors 18 genes for DM are isolated. Heritability of type 2 DM > type 1 DM. Although genetic susceptibility to type 1 DM Account for 40-80% of total disease is inherited, only 12-15% of type 1 DM occurs susceptibility. in families. In identical twins, 40-50% of second twin will 🅱 Lifestyle factors develop DM. ① Dietary factors  Diet high in total calories, total fat, 🅱 Environmental triggers saturated fats, cholesterol & refined sugar. ① Viral infection: ② Mental stress  Coxsackie B virus.  Depression, fear, anger, anxiety, lack of  Mumps. social support. Risk  Congenital rubella. ③ Obesity factors  CMV.  Up to 80% of all new cases of type 2 DM ② Nutritional factors: can be attributed to obesity.  Nitrosamines toxins found in: ④ Physical inactivity & sedentary life - Smoked &preserved food. - Food grow in area using fertilizers. ⑤ Diabetogenic drugs - Milk formula.  Thiazides diuretics.  Early introduction of cow milk.  Corticosteroids.  Vitamin D deficiency.  Hormonal contraceptives. ③ Immunological factors: 🅲 Intrauterine environment  Type 1 DM is a slow T-cell mediated  Inadequate nutrition in early pregnancy autoimmune disease. (critical stages of fetal development) is important in type 2 DM development. Dr. Strange Page 4  Community - Horus Semester 6 – Lecture 3  PREVENTION OF TYPE 1 DM  Antibody Screening ⎚ In type 1 DM, immune system attacks insulin-producing cells & produce antibodies against pancreatic tissue, which present up to 8 years before onset of DM. ⎚ If these antibodies are found, the child is at high risk for developing DM: Principle ▪ Islet cell antibodies “most widely used antibody markers”. ▪ Insulin autoantibodies (IAA). ▪ Glutamate decarboxylase antibodies (GADA). Indications ⎚ Screening should be restricted to at risk groups (1st degree relative of cases). ❷ Prevention of environmental triggers ① Prevention of viral infection: 1. General prevention measures. 2. Mass MMR immunization to prevent the risks of mumps & rubella. ② Health education of mothers: 1. Encourage breast feeding. 2. Delay introduction of cow milk. 3. Vitamin D supplementation in case of vitamin D deficiency. ❸ Trials to delay or arrest autoimmune process of type1 DM ⎚ Prophylactic insulin, oral glutamic acid decarboxylase & others. Dr. Strange Page 5  Community - Horus Semester 6 – Lecture 3  PREVENTION OF TYPE 2 DM  Primary prevention ① Identify high risk groups: 1. Cases with +ve family history especially 1st degree. 2. Obese individual. 3. Premature atherosclerosis. 4. Pregnant female with excessive weight gain. ② Nutritional Education “Diet modification of high-risk groups”: 1. Minimize carbohydrate consumption. 2. Avoid high fat diet, it is better to use mono-unsaturated fatty acids. 3. Increase the intake of high fibers diet. 4. Adequate nutrition during pregnancy. ③ Healthy lifestyle: 1. Promotion of physical exercise. 2. Avoid use of diabetogenic drugs among high risk individuals. ④ Control of obesity & maintain optimal body weight. ⑤ Premarital counseling & advice to avoid consanguineous marriage. ❷ Secondary prevention ① DM screening “for early case finding”: 1. For all adults at age 40 or 50 & then periodically. 2. Early screening for those with risk factors such as: Indications ▪ Obesity ▪ Family history of DM. ⎚ Screening test may be ▪ Random blood glucose test Method ▪ Fasting blood glucose test ▪ Glucose tolerance test “A blood glucose test 2 hours after 75 g of glucose” ② Control of DM: Aim ⎚ Maintain serum glucose level within normal 1. Life style & diet modification. Measures 2. Oral hypoglycemic. 3. Insulin use. Dr. Strange Page 6  Community - Horus Semester 6 – Lecture 3 ❸ Tertiary prevention (Prevention of DM complication) ① Glucose control: ⎚ In general, for every 1% ⇊ in HBA1c blood test (e.g. from 8% to 7%), risk of micro-vascular DM complications (eye, kidney & nerve disease) ⇊ by 40%. ② Blood pressure control: - CVDs (CHD & stroke) - 33-50%. - Microvascular diseases ⇊ Risk of By (%) - 33% (eye, kidney & nerve disease) - DM complication - 12% (For every 10 mmhg ⇊ in systolic BP) ③ Control of blood lipids: ⎚ Can ⇊ cardiovascular complications by 20-50%. ④ Preventive care for eyes, kidneys & feet: ⎚ Detecting & treating diabetic eye disease with laser therapy can ⇊ severe vision loss by 5-6%. ⎚ Comprehensive foot care programs can ⇊ amputation rate by 45-85%. ⎚ Detecting & treating early diabetic kidney disease can cause ⇊ in kidney function by 30-70%. Dr. Strange Page 7