metabolic effects of bariatric surgery on diabetes mr paras jethwa bsc md frcs frcs(gen surg)...
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Metabolic Effects of Bariatric Surgery on Diabetes
Mr Paras Jethwa BSc MD FRCS FRCS(Gen Surg)
Consultant Laparoscopic Surgeon
Definitions
• Body Mass Index = weight/height2
< 20 = underweight20-25 = normal25-30 = overweight30-40 = obese > 40 = morbidly obese
• Excess Weight = Current Weight – Ideal Weight
BMI > 30 1991
BMI > 30 1992
BMI > 30 1993
BMI > 30 1994
BMI > 30 1995
BMI > 30 1996
BMI > 30 1997
BMI > 30 1998
BMI > 30 1999
BMI > 30 2000
BMI > 30 2001
0
5
10
15
20
25
30
35
USA MEXICO UK SLOVAKIA GREECE AUSTRALIA NZ HUNGARY SPAIN IRELAND TURKEY SWEDEN FRANCE J APAN
Worldwide Obesity Prevalence (%)
Obesity Related Mortality
Type 2 DM
• >80% have BMI >25
• 50% obese, 10%>40%
• Modest weight loss helps control
• BUT - 95% will fail with diet
• Proposed in mid 90’s that T2DM– “Surgical disease”
– Foregut hormone stimulation
Surgical Options
• Restrictive vs. malabsorption• Restrictive:– Generating saiety signals
• Malabsorpative:– Gastric restriction– Duodenal and upper jejunal bypass
• Extreme (BPD & Switch)– Only last 50cm of SB used for digestion
Laparoscopic Gastric Band
• Mean = 47% EWL• Best for– BMI < 47 kg/m2
– Regular meal patterns– Non sweet eaters
• Mortality risk 1:800• Morbidity risk 1:100• 15% bands need revision
Laparoscopic Gastric Bypass
• Mean = 72% EWL• Best for– All BMI– Sweet eaters and grazers– Diabetics
• Mortality risk 1:300• Morbidity risk 1:75
Laparoscopic Sleeve
• Mean = 75% EWL?• Easy maintence• One long suture line• Poorer longterm• Removes Ghrelin producing cells• Mortality risk 1:400• Morbidity risk 1:100
Laparoscopic Mini Gastric Bypass• Mean = 80% EWL• Best for
– All BMI– Grazers– T2DM
• Mortality risk 1:500• Morbidity risk 1:80• Lower long term risk of metabolic
complications• Extensively practiced in US
MGB success
What mechanisms are at work?Bypass factors
• Foregut vs. Hindgut theories– Gherlin– Glucagon like peptide – Gut derived glucadonotropic signalling
• Diabetic effect seen before weight loss– Clear division contributes– RYB vs. Banding for speed of control
Weight loss factors
• Improvements insulin action/reduced resistance
• Relieve secretory pressure on ß cells• Early effect:– Calorific reduction - increase insulin sensitivity
• Later effect:– Absolute weight loss glycaemic control
Are the effects longlasting?
• Maximum wt loss is at 1-2 years• 30-50% excess wt loss at 6/12• 10-14 years post op - more favourable levels
of :– Cholesterol– DM– HT
Benefits
• 621 studies with 135, 246 patients• Mean age - 40.2 years• Mean BMI - 47.9• 80% Female
• 56% EBWL • 78% resolution of diabetes• BPD>RYB>LAGB• Effect static at 2 years
• Case controlled prospective study
• Surgery v control• 4047 patients• 99.9% follow up• Average 10.9 year follow up• Prospective SOS trial:
– Glucose/lipids/BP• 10.9 year FU - 30%
mortality
Non T2DM effects• SOS study
• 50% reduction in IHD• 85% reduction in sleep apnoea• Life expectancy improves up to 89%• Up to 40% reduction in premature death• 60% reduction in cancer deaths• Fatal IHD halved
0
10
20
30
40
50
60
70
80
90
DM Lipids HT SleepApnoea
% amelioration
Resolution / improvement of comorbidities
Prognostic factors for DM remission
• Type of op• Pro:
– Early rapid weight loss– Preoperative insulin dose
• Against:– Diabetes dutation (B cell mass)– High HbA1c– Insulin vs. oral therapy– Diabetic complications (retinopathy etc.)
• Unsure:– FH– Late onset type 1
Risks
• Remarkably safe• Mortality 0.1% to BPD 1.1%• 5-10% acute comps– Bleeds– Int. hernia– Anastomotic issues– Nutrition– Emotional
• Hypoglycaemia if medication unaltered
Metabolic SurgeryBMI > 40 or BMI >35 with ComorbidityNICE: CG43
Exhausted non surg methodsFit for opWillingFirst line for BMI>50 Part of MDTIn young in exceptional circumstances psychological factors etc.
Diabetes• Bypass:– Type 2 - 87% resolution
• Band– Type 2 - 73% resolution
• 92% mortality risk reduction
• Clinically and cost effective for moderate to severe obesity
Role of banding?• RCT of 80 patients• 2 year follow up• 87% v 22% excess weight
loss• Significant reduction in
metabolic syndrome
• 50-77% of obese adolescents carry their obesity into adulthood
Adolescents
• Rapidly growing group in US– Sequential family members
• Extremely obese teen– Treatment of choice?
• Radical step BUT…….– T2DM not uncommon in teens now– Given that we are following US trends…
Summary
• Obesity plays a key role in pathophysiology• Roux en Y bypass most effective• Effects not just related weight related• Useful adjunct in obesity esp. when DM difficult
to control• Surgical diversion leads to release of incretin • Type 2 DM evaluated at MDT
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