1. Medical Management of Obesity
Robert Schmidli
FRACP, PhD
Consultant Physician,
Diabetes and Endocrinology

2. Case history “Paul”: 38 years, public servant
Normal weight as child, football during teens. Stopped when 19
Weighed 70kg at 18y
Progressive weight gain. Now 130kg
Frequent travel and work lunches
Works late in evenings
No special attention to diet
No time for exercise

3. Examination Weight 130kg, height 1.8, BMI 40 Blood pressure 150/80
Healthy, no abnormality
Cholesterol 4.0
Fasting blood glucose 6.2
What are the main issues?
What should Paul do?

4. Definition Body mass index = weight  height2 Ideal: 20 – 25
Overweight: 25 – 30
Obese: > 30

5. How common is it? Australia second to USA in world AusDiab study:
Overweight 60% both sexes
2½ - fold increase in obesity compared to 1980
Associations:
Television viewing time
Lower physical activity time

6. Benefits of weight loss
9.1kg weight loss  35%  death rate
Surgery  69% cure of diabetes
Death rates lower in individuals trying to lose weight
Blood pressure  0.3 – 1.0 mmHg for each kg weight lost

7. Weight loss targets Diabetes Prevention Trial: 3234 people
High risk for diabetes
≥7% weight loss target
Exercise ≥ 150 min/week
16-lesson curriculum: diet, exercise, behavior modification
Flexible, individualized
Cost: $104,000,000

8. Reductions – Metformin: 31%, Lifestyle 58%

9. Medical causes Hypothyroidism Cushing’s syndrome Insulinoma
Underactive thyroid
Cold intolerance, fatigue, swelling
Cushing’s syndrome
Central obesity, moon face, stretch marks
Insulinoma
Hypothalamic damage
Head injury, surgery, infections
Uncommon!

10. Atkins diet High protein, low carbohydrate
Ketone production not demonstrated to occur
Greater weight loss at 6 but not 12 months compared to “conventional” diet
High dropout rates in both groups

11. Optifast (Modifast) diet
Liquid high-protein, low carbohydrate
Induces ketone formation
Can supplement with vegetables
3 months on, 6 months off
Appetite suppressants required when off
Very effective – 7-8 kg loss per month
Difficult to adhere to
Roles:
Weight loss before surgery
“Last resort” if not suitable for surgery

12. Drug treatment
Multiple hormones/neurotransmitters involved – “redundancy”
Weight gain when stopped
Effectiveness similar for all
Weight plateaus after several months
Expensive
Not covered by PBS

13. Orlistat (Xenical®) Inhibits absorption of fat Take before meals
Diarrhoea after eating fat
Expensive: $160/month
1kg per month. 12% had 10% loss
Non-toxic
Vitamin deficiencies

14. Sibutramine (Reductil®)
Affects appetite centre in brain
Once daily
Stimulant. Hypertension
Avoid in epilepsy
Need to monitor blood pressure
Similar effectiveness to Xenical
15% had 10% weight loss

15. Phentermine (Duromine®)
Stimulant
Cheaper than others ($68/month)
Often not tolerated because of side effects
Avoid in cardiac disease, hypertension
Interacts with other drugs

16. Conclusions Lack of exercise major problem
“Sensible” diet: avoid fat & simple sugars
Drugs have limited effectiveness, highly effective in some
Surgery: sustained weight loss, for more severe end of spectrum
Modifast: short-term, individuals with serious complications