Impact of Epidemiology on Diabetes Mellitus

1. Impact of Epidemiology on Diabetes Mellitus Echo Lecture from Thelma D. Crisostomo,MD

2. Epidemiology of Diabetes Mellitus Type II

3. Global – 2000 AD

4. Total Number of People with Diabetes Year 2000 171 Million Year 2030 366 Million

5. Developing Countries Most Affected In This Global Diabetes Epidemic

6. Certain Ethnic Groups Who Have ExperiencedRapid Modernization Of LifestyleDemonstrate The Greatest Susceptibility To Type 2 DM

7. 2000

8. Epidemiology Studies distribution and determinants of disease PURPOSE • To understand natural history, cause of the disorder and pathogenesis. • For appropriate diagnostic investigation and clinical management. • For creation of scientifically based program for prevention and health care.

9. The First Step Of Epidemiologic Research Begins With Measuring • Incidence • Number of new cases discovered for a specific time and place. • Used to identify epidemics. • Used to search for etiology • Prevalence • Total number of cases old and new occurring in a specified time and place. • Tool for determining public health needs.

10. Is There An Epidemic Of Type 2 Diabetes Mellitus? Epidemic – Definition The occurance in a community of a disease, infectious or chronic (e.g. diabetes mellitus), occurring at a greater frequency than usually expected. Does this apply to Type 2 DM? Yes, particularly in developing and newly industrialized nations.

11. Type 2 DM: A Public Health Prospective • Type 2 DM is among the top 7 cause of death in most countries. • Cardiovascular complications are major cause of morbidity and mortality: This results in the impact of type 2 DM being underestimated from death certificates. • There is an excessive frequency of coronary artery and peripheral vascular disease and strokes.

12. Type 2 DM: A Public Health Prospective • Type 2 DM is the most common cause of adult blindness and a common cause of renal failure and amputation. • Results in disability, reduced life expectancy and enormous health cost for any society.

13. Cause of Death in Type 2 DM

14. The true cost of treating T2DM is not the cost of oral hypoglycemics. The true cost come from treatingcomplications with non-OADs and other forms of treatment

15. Cost Associated with Type 2 Diabetes

16. Etiologic Classification of Diabetes Mellitus • Type 1 Diabetes (B-cell destruction, usually leading absolute insulin deficiency). • Immune mediated • Idiopathic • Type 2 Diabetes (may range from predominantly insulin resistance with relative insulin deficiency to a predominantly secretory defect with insulin resistance).

17. Etiologic Classification of Diabetes Mellitus • Other specific types • Genetic defects of B-cell function • Genetic defects in insulin action • Disease of the exocrine pancreas • Endocrinopathies • Drug – or – chemical – induced • Infections • Uncommon forms of immune-mediated diabetes • Other genetic syndromes sometimes associated with diabetes • Gestational diabetes mellitus (GDM)

18. Ratio of Diagnosed / Undiagnosed Type 2 DM

19. Prevalence of NIDDM in Selected Populations in the Age Range 30–64 Years

20. Year 2000 2.8% Year 2030 4.8% Prevalence of DM Worldwide

21. Global Diabetes Prevalence by Age and Sex for 2000

22. List of Countries with the Highest Numbers of Estimated Cases of Diabetes for 2000 and 2030

23. Estimated Number of Adults with Diabetes by Age-Group, Year, and Countries for the Developed and Developing Categories and for the World.

24. Estimated Number of Adults with Diabetes by Age-Group, Year, and Countries for the Developed and Developing Categories and for the World.

25. Prevalence of DM (Philippines)1982 - 1983

26. Prevalence of IGT (Philippines)1982 - 1983

27. What is the Prevalence of Diabetes Mellitus in the Philippines? • 2 out of 100 • 4 out of 100 • 6 out of 100 • 8 out of 100 • 10 out of 100 2.8 M Filipinos 5th National Nutrition Survey FNRI, DOST Oct 1999 N = 70, 000 99 areas

28. DiabetesGenetics Environment

29. Aetiology of NIDDM: The Interaction of Genetic Susceptibility and Environment Factors Heredity Genetic Susceptibility Obesity Physical inactivity Nutritional Factors Aging Intrauterine Factors Hyperinsulinemia Insulin Resistance Beta-cell Failure Type 2 DM

30. CollisionHunter Gatherer Genes VS 20th Century LifestyleType 2 DM

31. Thrifty Gene Hypothesis Past populations subjected to cycles of feast/famine Genes were adopted to store energy efficiently Rapid Modernization Famine rare. Abundant food stored efficiently Results in Obesity, hyperinsulinemia and diabetes

32. ‘Thrifty Genotype’(Hyperinsulinemia) Modern society Hunter-gatherer society Feast + famine Feast • Maximum metabolic efficiency • Hepatic gluconeogenesis • Hepatic lipogenesis • Selective insulin resistance in muscle • Insulin resistance • diet energy dense, high saturated fat • Physical inactivity • Obesity •  B-cell exhaustion Survival Glucose intolerance Dyslipidemia Hypertension A proposal for the operation of the “thrifty genotype” in the pathogenesis of non-insulin dependent diabetes and other associated cardiovascular disease risk factors in populations who have changed their life-style from hunter gatherer to modern.

33. Age-Standardized prevalence of diabetes in adults in “urban” pacific populations (25-74 years)

34. Prevalence of diabetes by ethnic groups in Mauritius (25-74 years). Age-standardized by direct method to total Mauritius population – 1986.

35. Prevalence of NIDDM in Chinese (30 – 64 years) in China, Singapore and Mauritius. Age-standardized by the direct method to Segi’s world population.

36. Stages in the Development of Type 2 DM Genetic susceptibility  Hyperinsulinemia and/or insulin resistance  Impaired glucose tolerance  Non-insulin dependent diabetes

37. Normal IGT Type 2 Diabetes Development of Type 2 Diabetes

38. Type 2 Diabetes IGT Impaired Glucose Metabolism Normal Glucose Metabolism Development of Type 2 Diabetes Macrovascular disease is closely linked to Insulin Resistance Groop Etiology of non-insulin-dependent diabetes mellitus. Hormone Res. 1997; 22:131-156

40. Studies that Confirm the Strong Genetic Basis of Type 2 DM • Twin studies • Familial aggregation • High prevalence population • Genetic Admixture studies • Prevalence in different ethnic groups in same environment • MODY/Nauruans/Pimas – autosomal dominant inheritance

41. Genetic Factor Type 2 DM – 100% Concordance in Identical Twins Type 1 DM – 30-50% in Concordance in Identical Twins

42. Impaired Glucose Tolerance Worsening to Diabetes in Siblings Overall Occurrence Rate Diabetes 12% Impaired Glucose Tolerance 12%

43. IGT Worsening to Diabetes Filipino Siblings 50% Conversion in 8 years Conversion rate: 9.3 per 100 cases/year

44. IGT Conversion Rate PIMA Indians 9.3 cases per 1000/year Filipino Siblings

45. 10 yr Follow up Impaired Glucose Tolerance (IGT)Natural History Subjects with IGT

46. Major Behavioral, Environmental and Social Risk Factors for Type 2 DM These may vary within and between populations and include: • Age • Nutritional factors • Obesity (central) • Physical inactivity • Degree of modernization • Intra-uterine environment • ? Stress, ? others

47. Fat 40+% Fat 15 to 20% Fat 10 to 15% Sugar 5% Sugar 20% Starch 50 to 70% Starch 60 to 75% Starch 23 to 30% Protein 12% Protein 15 to 20% Protein 10 to 15% Changes in Component of the Diet that Have Been Seen in the Change From Hunter Gatherer to the Modern “Western” Diet

48. High Fat, High Simple Sugar Low Complex Carbohydrate Diet in westernized Societies are contributing to the excess Obesity and NIDDM

49. Environmental Determinant of Type 2 DM Obesity If there were no obesity, the prevalence of diabetes would be greatly reduced

50. Central Distribution of Body Fats as Risk Factor for NIDDM Implicated in: • Europids (Sweden) • Mexican Americans • Native Americans • Micronesians (Nauruans) • Asian Indians (Hindu and Muslim) • Creoles • Chinese • Japanese Americans