Clinical Staging for Obesity Raj Padwal Clinical Pharmacology and General Internal Medicine University of Alberta
Disclosures Funding: CIHR, Heart and Stroke Foundation of Canada, University Hospital Foundation. Research Collaboration: Novo Nordisk, CVRx Speaking and other Honoraria: none
Key Points 1. BMI is only an indirect measure of adiposity a. Good for epidemiological studies b. Limited use for measuring individual risk 2. Comorbidity based classification systems offer improved predictive risk a. Complementary role anthromopetric indices
Body Mass Index AdolpheQuetelet (1796 1874) Weight is more or less height squared
BMI and Mortality Risk 19 prospective studies with nearly 1.5 million white adults. Gonzalez et al. NEJM 2010
BMI and Body Fat European South Asian DXA scan of two individuals with the same BMI but markedly different percent body fat Yudkin & Yainik, Lancet 2004
Relationship Between BMI and Percent Body Fat in Men and Women Body Fat (%) 70 60 50 40 30 20 10 0 0 Women Men 10 20 30 40 50 60 Body Mass Index (kg/m 2 ) Adapted from: Gallagher et al. Am J Clin Nutr 2000;72:694.
Health Hazards of Obesity Know the grave doth gape For thee thrice wider than for other men Adolf Schrodter: Falstaff and his page Henry IV William Shakespeare (1564 1616)
Medical Complications of Obesity Pulmonary Disease abnormal function obstructive sleep apnea hypoventilation syndrome Nonalcoholic Fatty Liver Disease steatosis steatohypatitis cirrhosis Gall Bladder Disease Gynecologic Abnormalities abnormal menses infertility polycystic ovarian syndrome Osteoarthritis Skin Gout Idiopathic Intracranial Hypertension Stroke Cataracts Accelerated Atherosclerosis Coronary Heart Disease Diabetes Dyslipidemia Hypertension Severe Pancreatitis Cancer breast, uterus, cervix, colon, esophagus, pancreas, kidney, prostate Phlebitis venous stasis Source: CON 9/33
Comorbidity Based Classification
King s Obesity Staging Criteria Aasheim et al. ClinObes 2011
King s Obesity Staging Criteria 144 patients before and one year after bariatric surgery. Aasheim et al. ClinObes 2011
Edmonton Obesity Staging System (EOSS) Stage 2 co-morbidity Stage 1 moderate Stage 3 end-organ damage moderate pre-clinical risk factors severe mild severe mild Stage 0 Stage 4 end-stage end-stage end-stage Obesity absent absent absent Medical Mental Functional Sharma AM & Kushner RF, Int J Obes 2009
Objective To determine if the EOSS independently predicts mortality in a population based sample
Objectives Examined the association between EOSS and mortality in models adjusted for BMI and metabolic syndrome as well as BMI and hypertriglyceridemic waist. Examined the predictive ability in subgroup eligible for bariatric surgery.
Methods Data source: NHANES III (1988 94) (n=4367) and NHANES 1999 2004 (n=3600; 3 2 y cycles) representative sample of the US noninstitutionalized population Overweight and obese adults randomized to the Mobile Examination Center morning subsample Endpoint: mortality by linking to public use files in the National Death Index Follow up to end 2006
Methods: EOSS Assignment Parameter EOSS 0 EOSS 1 EOSS 2 EOSS 3 Blood pressure Optimal pre HTN HTN Cholesterol Optimal borderline high Glucose Optimal Pre diabetes DM Liver disease (partly SR) Normal Elevated liver E OA (SR) None Joint pain in past year but no OA Physical health (SR) normal Physical impairment but no ADL limit Elevated liver E and liver dz OA ADL limit GFR 90 60 89 30 59 <30 Patients with CAD, CVD, CHF (all SR) assigned to EOSS 3.
EOSS and Mortality
EOSS and Mortality
EOSS and Mortality
EOSS and Mortality
EOSS and Mortality Within BMI Class Overweight
EOSS and Mortality Within BMI Class
NHANES III Results (Cox Model) Variable (Reference) EOSS Stage (Stage 0/1) HR (95% CI) EOSS Stage 2 1.6 (1.2 2.1) EOSS Stage 3 2.7 (2.0 3.7) BMI (Overweight) Class I 1.2 (1.01 1.5) Class II 1.7 (1.2 2.5) Class III 1.5 (0.9 2.5) Metabolic Syndrome (absent) 1.1 (0.98 1.3)
NHANES III Results (Cox Model) Variable (Reference) HR (95% CI) EOSS Stage (Stage 0/1) EOSS Stage 2 1.6 (1.2 2.2) EOSS Stage 3 2.8 (2.1 3.7) BMI (Overweight) Class I 1.3 (1.03 1.6) Class II 1.8 (1.3 2.6) Class III 1.6 (1.02 2.6) Hypertrig Waist (absent) Age 60 y 1.2 (0.7 1.9) Age 61 81 0.9 (0.7 1.1) Age 82 0.9 (0.7 1.1)
NHANES III Results (Cox Model) Bariatric Surgery Eligible (n=546) Variable (Reference) EOSS Stage (Stage 0/1) HR (95% CI) EOSS Stage 2 3.9 (0.8 18.8) EOSS Stage 3 12.3 (2.1 72) BMI (Class II) Class III 0.9 (0.4 2.0) Metabolic Syndrome (absent) 1.3 (0.6 3.1)
Limitations of Comorbidity Based Scores Requirement for detailed information? Simplified version Arbitrarily considered comorbidities as equivalent e.g. diabetes and osteoarthritis? Weighted version
Key Points 1. BMI is only an indirect measure of adiposity a. Good for epidemiological studies b. Limited to measure individual risk 2. Comorbidity based classification systems offer improved predictive risk a. Complementary role anthromopetric indices