special cases in hypertension: morbid obesity simon thom 31 st october 2006
TRANSCRIPT
Special cases in hypertension:
Morbid obesity
Simon Thom
31st October 2006
1949 “…an epidemic; under the right economic & social
circumstances, obesity from overeating will be a dominant nutritional problem.”
1965 “While our calorie input goes up our output goes down.
The wonderful advances of technology not merely free us from back-breaking toil; they make it almost impossible to get a decent amount of calorie-using exercise.”
Ancel Keys
BMI Classification
<18.5 underweight
18.5-24.9 healthy
25-29.9 overweight
30-30.9 obese
>40 Morbidly obese
WHO classification of body fatness based on BMI
Weight or waist?
Han TS et al. ABC of obesity. BMJ 2006http://www.who.int/topics/obesity/en/
Romero-Corral A et al. Lancet 2006; 368: 666
Low weight
Normal weight
Over weight
Obese Severely obese
RR for total mortality in patients with CAD by BMI groups R
ela
tive
ris
k, d
eath
Metaanalysis250,152 patients; 3.8 yrs f-up
Relative risk for death among women who never smokedby maximum BMI & % maximum weight lostDeaths in first 8 years after baseline were excluded
Pamuk ER et al. Ann Intern Med 1993; 119: 744
Rel
ativ
e ris
k, d
eath
NHANES I2453 men & 2739 women 45-74 yrs followed 1971 to 1987
A paradox of BMI ?
These three people ……
may have similar BMI!
Obesity decile
Nine year age-adjusted IHD mortality rate by obesity decile & systolic BP
Is hypertension more benign when associated with obesity?9
year
mor
talit
y ra
te /
100
Barrett-Connor E, Khaw KT. Circulation 1985; 72: 53
Association of BMI & waist-hip ratio with MI risk
controlscases
OR
(95
% C
I)
BMI quintiles Waist-hip ratio quintiles
Yusuf S et al. Lancet 2006; 366: 1640INTERHEART; 12461 MI cases 14637 controls
Han TS et al. BMJ 2006; 333: 695Han TS et al. Int J Obes Relat Metab Disord 1997; 21: 587
Strong correlation of visceral fat with waist circumference
Haslam D et al. BMJ 2006; 333: 640
Childhood prevalence of obesity (BMI >30)Health Survey for England 2002
If current trends continue, nearly a third of boys & girls aged under 11 will be obese or overweight by 2010
Time trend in percentages of obese US children & teenagers
Nestle M. NEJM 2006; 354: 2527McGinnis JM. Nat Acad Press 2006
There are now more young people who are overweight through calorie excess
than there are young people who are starving.
Health consequences of obesity
+GoutCancersPre-eclampsiaFetal defectsBack painOsteoarthritisInfertilityHeart failureAtrial fibrillation…….
RR for hypertension according to weight change after age 18 yrs within strata of age
Huang Z. et al. Ann Intern Med 1998; 128: 81
US Nurses Health Study
82,473 nurses; 30 – 55yrsF-up biannual since 197616,395 hypertension cases
Adjusted for BMI at 18, FH of CHD, parity, OCP use, menopausal status, HRT use, smoking
AdiposeTissue
Adiponectin Unknown factors
Factors secreted by adipose tissue
Bone morphogenic protein
Resistin
Adipsin
Estrogen
ANG-II
AngiotensinASP Leptin
PAI-1
Retinol
CRP
Fatty acidsLysophospholipid LactateAdenosineProstaglandinsGlutamine
TNF-IL-6,IL-8TGF-FGFEGF
IGF-IIGFBP
Reaven P. J Insur Med 2004; 36: 132
Lau DCW et al. Am J Physiol 2005; 288: H2031
Anti- & pro- inflammatory adipokines
“Uniquely among chronic diseases, obesity does not need a scientific breakthrough to be treated successfully. Enough is known about the causes of obesity and that diet, exercise, behaviour therapy and laparoscopic surgery can be effective.”
Sattar N et al. ABC of obesity series. BMJ 2006
Twisk JW. The Amsterdam Growth and Health Study
Am J Epidemiol 1997; 145: 888
Wilsgaard T. The Tromso Study Am J Epidemiol 2001; 154(5): 418
Kuh DJ. MRC National survey J Epidemiol Community Health
1992; 46: 114
Tracking of CVD risk factors
Behavioural patterns – smoking, physical activity, eating habits and weight tracking from childhood, through adolescence to adulthood. Kvaavik E. Oslo Youth Study
Arch Ped Adolesc Med 2004; 157: 1212
Stevens VJ. Ann Int Med 2001; 134: 1-11
Adjusted for age, ethnicity & sex according to quintile of weight change at 36 months (weight loss & usual care groups combined)
Diff
eren
ce f
rom
bas
elin
e B
P (
mm
Hg) Systolic BP
Diastolic BP
Quintile of weight change1 32 4 5
6
4
2
0
-2
-4
-6
-8
-10
Trials of Hypertension Prevention II mean change in BP by quintile of weight change
-8.8 kg -2.6 kg -0.1 kg 2.6 kg 7.3 kg
1191 men & women, high normal BP 110-165% overweight, 3 yrs f-up
Weight gain on -blocker therapy compared with control
Sharma AM et al. Hypertension 2001; 37: 250
Wansink B et al. Ann Int Med 2006; 145: 326
Fat & thin people fail to guess the calorie content of large meals
Distribution of actual & estimated calories of self-selected (top) & experimenter selected (bottom) fast-food meals by thinner & fatter participants.
Use a smaller plate !
The energy gap
The energy gap that explains the increased prevalence of obesity is only ~100 kcal/day.
This means that most of the population weight gain could be eliminated by a combination of increasing energy expenditure & reducing energy intake by 100 kcal/day.
Walking a mile, whether done all at once or divided up across the day, burns ~100 kcal.
Hill J. Science 2003; 299: 853Levine JA. Science 2005; 307: 584
Lean M et al. BMJ 2006; 333: 794Finer N Eur Heart J 2005; 26(7S): 32
Participants achieving 5-10% weight loss in one year(data from combined datasets of 1 year phase 3 trials)
5 mg vs. placebo: p < 0.00120 mg vs. placebo: p < 0.001
5 mg vs. placebo: p = 0.02920 mg vs. placebo: p < 0.001
Wai
st c
ircu
mfe
ren
ce c
han
ge
(cm
)
Wei
gh
t ch
ang
e (k
g)
Weeks
Weeks
Waist (cm)Waist (cm)Weight (kg)Weight (kg)
Placebo Rimonabant 5mg Rimonabant 20mg
Pi-Sunyer FX et al. JAMA 2006; 295: 761
Rimonabant, effects on weight & CVD RFs, RIO-North AmericaChange from baseline for body weight & waist circumference over year 1
A hollow band is placed around the stomach near its upper end, creating a small pouch & a narrow passage into the larger remainder of the stomach. The band is then inflated with saline. It can be tightened or loosened to change the size of the passage by increasing or decreasing the volume of saline.
http://www.ossanz.com.au/lapband.asphttp://www.lapband.com.au/
Bariatric surgery; adjustable laparoscopic gastric banding
Maggard MA et al. Ann Intern Med 2005; 142: 547
Bariatric surgical procedures
Trends in numbers of bariatric procedures, US 1998-2003
Santry HP et al. JAMA 2005; 294: 1909
No.
of p
roce
dure
s, th
ousa
nds
Laparoscopic banding
Before After
Sjöström L et al. NEJM 2004; 351: 2683
Swedish Obese Subjects Study, 4047 subjects BMI ~40 surgery or matched controlsweight Changes over 10 years
Sjöström L et al. NEJM 2004; 351: 2683
Lower 2- & 10-yr incidence of DM, hypertriglyceridemia & hyperuricemia in surgery group
No difference in incidence of hypertension & hypercholesterolemia
% BP at 2-yrs 2.8 / 3.2
% BP at 10-yrs 1.1 / -2.3
Swedish Obese Subjects Study
Incidence of DM, high lipids, hypertension & hyperuricemia
over 2- & 10-yrs
Stanley S et al. Physiol Rev 2005; 85: 1131
Control of energy homoestasis by peripheral signals from adipose tissue, pancreas & the GI tract
Scripps ghrelin vaccine was injected into male rats. Ghrelin secreted by the rats when they had not eaten is sequestered by vaccine-induced antibodies, reducing the ability of ghrelin to reach the brain, where it acts
Zorrilla E. (& Janda). Proc. Natl. Acad. Sci. USA, DOI:10.1073/pnas.0605376103
