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

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

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?

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

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

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

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

Reductions – Metformin: 31%, Lifestyle 58%

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!

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

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

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

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

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

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

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