1. END2.21 - Obesity Dr Gul Bano © S Nussey

2. What is obesity?

5. How is obesity defined?

6. How to measure obesity? BMI = Weight/height 2 - using metric not Imperial measures

7. How to measure obesity? cm

8. Who is obese?

9. Age and sex effects Who is obese?

10. Effect of ethnic group Who is obese?

11. Effect of educational level Who is obese?

13. Why treat obesity? Effect of obesity on all-cause deaths

14. Why treat obesity? Effect of obesity on coronary disease deaths

15. Why treat obesity? Effect of obesity on Type 2 DM

16. Quantification of weight gain as a risk factor for diabetes US female nurses study - 114,281 - age 30-55 y with no DM, stroke, CAD or cancer at entry. Prospective cohort study 1976-90 (98% White). Outcome measure - NIDDM 2204 cases during 1.49 million woman-years. After age adjustment, BMI was the dominant predictor of NIDDM Ann Intern Med 1995, 122: 481.

17. US Nurses study Relative risk adjusted for age Attained BMI 2.9 4.3 replotted

18. US Nurses study Relative risk adjusted for age and BMI at 18y Loss (kg)Gain (kg) Weight change from age 18 to 1976

19. Effect of weight gain from 18y to 1982 on relative risk stratified for FH

20. Quantification of weight gain as a risk factor for diabetes NHANES I - 14,407 US adults >25y 1971-5, followed to 1992. Weight change from recruitment to first follow up in 1982-4. Outcome measure - NIDDM 27% increased risk for gains of 5kg or more Every kg increase produces 4.5% increase in risk Am J Epidemiol 1997, 146: 214

21. NHANES I Study *corrected for age, sex, race,education, smoking, cholesterol, bp, alcohol

22. Effects of weight loss on diabetes associated mortality US Cancer Prevention Study I 1959-60 - 1,078,894 men & women age > 30y with 91% follow up to 1972. 52,207 white women age >40 and 27 at recruitment, 15,069 with ‘obesity related health condition’ (heart disease, stroke, diabetes, hypertension). Outcome measure - Death certificate ICD-7 code 260 Am J Epidemiol 1995, 141:1128

23. Cancer Prevention Study I *corrected for initial age and BMI, education, alcohol, physical activity, other illnesses

24. How to treat obesity?

25. Representative outcomes of therapy

26. Treating obesity Overlapping activities in an integrated approach

27. Current potential integration

28. Effectiveness of lifestyle changes in general practice Meta-analysis - smoking, alcohol, diet and exercise. Randomised trials including ‘usual care’ arm, published in English. 6 electronic databases and 37 trials. Only smoking intervention could be analysed. None showed substantial change Family Practice 1997, 14:160

29. Shared Care Approach - 1 Australian study of shared care vs hospital based 37 shared care vs 101 gender-, age- and BMI- matched hospital care patients. Food habits by questionnaire, weight, BMI with comparisons at 10 and weeks. Jointly designed protocol. NB fewer GPs signed up for obesity shared-care protocol than for other protocols. Int J Obesity 1996, 20:413

30. Shared Care Approach - 2

31. Changes in BMI in the Minnesota Heart Health Program 6 communities in 3 states - 500,000 people Mass media, physician education, risk factor screening, adult education, environmental programs, youth education for 7 years in 3. Obesity not primary outcome but included. Cross-sectional and cohort studies BMI increased with time and was unaffected by intervention. Int J Obesity 1995, 19:30.

32. Changes in BMI in the Stanford 5-city project 2 treatment cities n=122,800 received 6 yr mass media and community cardiovascular risk reduction program. BMI a primary outcome Cross-sectional and cohort studies BMI increased with time and was unaffected by intervention. Am J Epidemiol 1991, 134:235

33. Physician Surgeon Psychologist Dietitian Community

34. Mechanism - 1 ‘Medicalise’ the problem Provide means Motivate Reinforce Establish individual responsibility Set individual long-term targets Focus Use individualised objective measures Measure

35. Mechanism - 2 ‘Medicalise’ the problem Entry into main- stream medicine Avoids suggestion of moral turpetude Establishes patho-physiological mechanism Provides mechanism by which socio-political issues can be addressed

36. Mechanism - 3 Individual Responsibility Clear definition of risk, comparable with smoking, bp, lipids Motivation Clarity of purpose and targets for therapy Reinforces medical model Avoids comparisons

37. Conclusion Obesity should be managed as a disease entity by a physician-centred multidisciplinary team. Evidence for long-term success of commercial community-based treatment is sparse. Evidence for the success of non-commercial community-based management (however desirable) is negligible.

38. Means Eating pattern modification –+ Behaviour therapy eg eating situation –+ Appetite suppression eg sibutramine –+ Fat malabsorption eg orlistat –+ Group therapy eg ‘Weight Watchers’ –+ Gastric balloon or waist cord –+ Surgery eg banded gastroplasty Exercise

39. Medical treatment of obesity Dexfenfluramine - withdrawn Orlistat - fat malabsorption Sibutramine - centrally acting

40. Sibutramine

41. Orlistat

42. Conclusion Moderate weight loss (~10% or 10kg) is associated with - –A significant reduction in diabetes incidence and associated mortality –Improved metabolic control in established diabetes This can be achieved with medical therapies More significant weight loss in morbid obesity can currently only be achieved by surgical techniques