Medical Management of Obesity

Medical management of Obesity

Henry Buchwald (coined the term “metabolic surgery”): “Metabolic surgery is cognitive surgery”

What is medical management

  • Dietary and physical activity (PA) modifications: reduce intake by 500-1000 kCal/day, increase activity to 60mins 5 days/week.
  • The aim should be to lose 0.5-1kg/week until they lose 5-10% of weight
  • If after 6 months, significant weight loss not achieved, can add obesity drugs.

Initiating medical treatment

  • ASK
    • permission to discuss weight, be non-judgemental
  • ASSESS 
    • health conditions,
    • measure BMI, waist circumference, waist-to-hip ratio,
    • look for causes of weight loss and barriers to change
  • ADVICE
    • About risk of obesity
    • Explain benefits of weight loss
    •  Explore treatment options
  • AGREE
    • On a realistic weight loss target
    • On modality to use (and include a behavioural technique)
  • ASSIST
    • In identifying and addressing barriers
    • Arrange a regular follow-up

  • BMI >30 kg/m2 results in a reduction of 7 years of life for men and 6 years for women, compared to BMI<25
  • Waist circumference <102cm in men and >88cm in women = increase in diabetes and CVR
  • Therefore, if these are present, then treatment should be started. However, if diabetes, OSA or CVD are present then treatment should be started if BMI >27

Assessment of causes:

  • Genetics: Onset before 5 years of age, short stature, hyperphagia, diarrhoea and strong family history: eg. Prader-Willi Syndrome; do NOT respond well to obesity surgery
  • Eating disorders: eg. binge eating disorder (BED) and night-time eating syndrome (NES- morning anorexia, evening hyperphagia and insomnia)
  • Medical conditions: hypothyroidism, hypogonadism and Cushing’s
    • Treatment helps to reduce weight and cardiovascular risk
  • Psychiatric disorders: obesity causes depression/low self-esteem/anxiety/self-harm
  • Medications: can often be swapped to weight neutral/weight-loss promoting medications (includes anti-psychotics, antidepressarnts, anticonvulsants, diabetes – insulin, antihypertensives, OCPs)

Treatment

  • Eating disorders:
    • BED should be treated with CBT/interpersonal psychotherapy (IPT) and drug therapy. If they are particularly sweet bingers, results are likely to be poor post surgery. Otherwise evidence seems to be equal to non-bingers.
    • NES is harder to treat. CBT and ITP can help. Sertraline reduces eating in the evening. There does seem to be benefit to these patients from bariatric surgery.
  • Lifestyle modification:
    • Aim is to lose 5% over 6 months, then another 5% over next 6 months. This results in physiological benefits (insulin sensitivity, BP, mortality etc)
    • Weight loss is dependent on reducing total caloric intake. Good weight loss programmes can help. PA (daily activities for longer times) and exercise (repetitive, structured activities)  should be increased, 30mins 3 days/week to 60mins 5 days/week
    • Its essential for patients to record intake and activities to have a realistic reflection
  • Weight loss drugs
    • Used if lifestyle modifications not worked after 6 months
    • Only ORLISTAT is licensed for use in USA and Europe
      • Lorcaserin and phentermine/topiramate licensed in US only
    • Unlicensed drugs are metformin, SSRI and topiramate are often tried in specialist clinics
  • ORLISTAT
    • Lipase inhibitor, blocks digestion of ~30% of dietary fats
    • In trials, pts lose ~3kg more than controls at 3 months and 5% at 5months
  • Lorcaserin
    • 5-HT receptors, which cause serotonin release, reduce appetite
    • Lorcaserin is a selective 5-HT2C (HT2A causes hallucinations, HT2B causes cardiovascular risk factors and pulmonary hypertension)
  • Combination drugs are being developed as single drug outcomes are disappointing

Who to refer for Bariatric Surgery

  • In the UK, NICE state surgery should be offered to those with BMI>35 or those with BMI>30 and associated co-morbidities.
  • Decision should be made with psychosocial health, adherence, expectations and cost born in mind.
  • Contraindications are
    • high operative risk
    • active substance abuse
    • uncontrolled psychological disorder
    • recent serious life-event (eg. death of family member)
  • All patients should undergo assessment by multidisciplinary weight management team
  • Co-morbidities should be optimised
  • Patients should be screened for nutritional deficiencies